dropshell release 2025.0513.2134

build_amd64/_deps/zstd-src/tests/fuzz/.gitignore

@@ -0,0 +1,31 @@
+# test artefacts
+corpora
+block_decompress
+block_round_trip
+dictionary_decompress
+dictionary_loader
+dictionary_round_trip
+dictionary_stream_round_trip
+raw_dictionary_round_trip
+simple_compress
+simple_decompress
+simple_round_trip
+stream_decompress
+stream_round_trip
+zstd_frame_info
+decompress_dstSize_tooSmall
+fse_read_ncount
+sequence_compression_api
+seekable_roundtrip
+huf_decompress
+huf_round_trip
+fuzz-*.log
+rt_lib_*
+d_lib_*
+crash-*
+decompress_cross_format
+generate_sequences
+
+# misc
+trace
+tmp*

build_amd64/_deps/zstd-src/tests/fuzz/README.md

@@ -0,0 +1,161 @@
+# Fuzzing
+
+Each fuzzing target can be built with multiple engines.
+Zstd provides a fuzz corpus for each target that can be downloaded with
+the command:
+
+```
+make corpora
+```
+
+It will download each corpus into `./corpora/TARGET`.
+
+## fuzz.py
+
+`fuzz.py` is a helper script for building and running fuzzers.
+Run `./fuzz.py -h` for the commands and run `./fuzz.py COMMAND -h` for
+command specific help.
+
+### Generating Data
+
+`fuzz.py` provides a utility to generate seed data for each fuzzer.
+
+```
+make -C ../tests decodecorpus
+./fuzz.py gen TARGET
+```
+
+By default it outputs 100 samples, each at most 8KB into `corpora/TARGET-seed`,
+but that can be configured with the `--number`, `--max-size-log` and `--seed`
+flags.
+
+### Build
+It respects the usual build environment variables `CC`, `CFLAGS`, etc.
+The environment variables can be overridden with the corresponding flags
+`--cc`, `--cflags`, etc.
+The specific fuzzing engine is selected with `LIB_FUZZING_ENGINE` or
+`--lib-fuzzing-engine`, the default is `libregression.a`.
+Alternatively, you can use Clang's built in fuzzing engine with
+`--enable-fuzzer`.
+It has flags that can easily set up sanitizers `--enable-{a,ub,m}san`, and
+coverage instrumentation `--enable-coverage`.
+It sets sane defaults which can be overridden with flags `--debug`,
+`--enable-ubsan-pointer-overflow`, etc.
+Run `./fuzz.py build -h` for help.
+
+### Running Fuzzers
+
+`./fuzz.py` can run `libfuzzer`, `afl`, and `regression` tests.
+See the help of the relevant command for options.
+Flags not parsed by `fuzz.py` are passed to the fuzzing engine.
+The command used to run the fuzzer is printed for debugging.
+
+Here's a helpful command to fuzz each target across all cores,
+stopping only if a bug is found:
+```
+for target in $(./fuzz.py list); do
+    ./fuzz.py libfuzzer $target -jobs=10 -workers=10 -max_total_time=1000 || break;
+done
+```
+Alternatively, you can fuzz all targets in parallel, using one core per target:
+```
+python3 ./fuzz.py list | xargs -P$(python3 ./fuzz.py list | wc -l) -I__ sh -c "python3 ./fuzz.py libfuzzer __ 2>&1 | tee __.log"
+```
+Either way, to double-check that no crashes were found, run `ls corpora/*crash`.
+If any crashes were found, you can use the hashes to reproduce them.
+
+## LibFuzzer
+
+```
+# Build the fuzz targets
+./fuzz.py build all --enable-fuzzer --enable-asan --enable-ubsan --cc clang --cxx clang++
+# OR equivalently
+CC=clang CXX=clang++ ./fuzz.py build all --enable-fuzzer --enable-asan --enable-ubsan
+# Run the fuzzer
+./fuzz.py libfuzzer TARGET <libfuzzer args like -jobs=4>
+```
+
+where `TARGET` could be `simple_decompress`, `stream_round_trip`, etc.
+
+### MSAN
+
+Fuzzing with `libFuzzer` and `MSAN` is as easy as:
+
+```
+CC=clang CXX=clang++ ./fuzz.py build all --enable-fuzzer --enable-msan
+./fuzz.py libfuzzer TARGET <libfuzzer args>
+```
+
+`fuzz.py` respects the environment variables / flags `MSAN_EXTRA_CPPFLAGS`,
+`MSAN_EXTRA_CFLAGS`, `MSAN_EXTRA_CXXFLAGS`, `MSAN_EXTRA_LDFLAGS` to easily pass
+the extra parameters only for MSAN.
+
+## AFL
+
+The default `LIB_FUZZING_ENGINE` is `libregression.a`, which produces a binary
+that AFL can use.
+
+```
+# Build the fuzz targets
+CC=afl-clang CXX=afl-clang++ ./fuzz.py build all --enable-asan --enable-ubsan
+# Run the fuzzer without a memory limit because of ASAN
+./fuzz.py afl TARGET -m none
+```
+
+## Regression Testing
+
+The regression test supports the `all` target to run all the fuzzers in one
+command.
+
+```
+CC=clang CXX=clang++ ./fuzz.py build all --enable-asan --enable-ubsan
+./fuzz.py regression all
+CC=clang CXX=clang++ ./fuzz.py build all --enable-msan
+./fuzz.py regression all
+```
+
+## Fuzzing a custom sequence producer plugin
+Sequence producer plugin authors can use the zstd fuzzers to stress-test their code.
+See the documentation in `fuzz_third_party_seq_prod.h` for details.
+
+## Adding a new fuzzer
+There are several steps involved in adding a new fuzzer harness.
+
+### Build your harness
+1. Create a new your fuzzer harness `tests/fuzz/your_harness.c`.
+
+2. Add your harness to the Makefile
+
+    2.1 Follow [this example](https://github.com/facebook/zstd/blob/e124e39301381de8f323436a3e4c46539747ba24/tests/fuzz/Makefile#L216) if your fuzzer requires both compression and decompression symbols (prefix `rt_`). If your fuzzer only requires decompression symbols, follow [this example](https://github.com/facebook/zstd/blob/6a0052a409e2604bd40354b76b86272b712edd7d/tests/fuzz/Makefile#L194) (prefix `d_`).
+    
+    2.2 Add your target to [`FUZZ_TARGETS`](https://github.com/facebook/zstd/blob/6a0052a409e2604bd40354b76b86272b712edd7d/tests/fuzz/Makefile#L108).
+    
+3. Add your harness to [`fuzz.py`](https://github.com/facebook/zstd/blob/6a0052a409e2604bd40354b76b86272b712edd7d/tests/fuzz/fuzz.py#L48).
+
+### Generate seed data
+Follow the instructions above to generate seed data:
+```
+make -C ../tests decodecorpus
+./fuzz.py gen your_harness
+```
+
+### Run the harness
+Follow the instructions above to run your harness and fix any crashes:
+```
+./fuzz.py build your_harness --enable-fuzzer --enable-asan --enable-ubsan --cc clang --cxx clang++
+./fuzz.py libfuzzer your_harness
+```
+
+### Minimize and zip the corpus
+After running the fuzzer for a while, you will have a large corpus at `tests/fuzz/corpora/your_harness*`.
+This corpus must be minimized and zipped before uploading to GitHub for regression testing:
+```
+./fuzz.py minimize your_harness
+./fuzz.py zip your_harness 
+```
+
+### Upload the zip file to GitHub
+The previous step should produce a `.zip` file containing the corpus for your new harness.
+This corpus must be uploaded to GitHub here: https://github.com/facebook/zstd/releases/tag/fuzz-corpora
+
+

build_amd64/_deps/zstd-src/tests/fuzz/block_decompress.c

@@ -0,0 +1,53 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target attempts to decompress the fuzzed data with the simple
+ * decompression function to ensure the decompressor never crashes.
+ */
+
+#include "fuzz_data_producer.h"
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "fuzz_helpers.h"
+#include "zstd.h"
+
+static ZSTD_DCtx *dctx = NULL;
+static void* rBuf = NULL;
+static size_t bufSize = 0;
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    size_t const neededBufSize = ZSTD_BLOCKSIZE_MAX;
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+
+    /* Allocate all buffers and contexts if not already allocated */
+    if (neededBufSize > bufSize) {
+        free(rBuf);
+        rBuf = FUZZ_malloc_rand(neededBufSize, producer);
+        bufSize = neededBufSize;
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+    ZSTD_decompressBegin(dctx);
+    ZSTD_decompressBlock(dctx, rBuf, neededBufSize, src, size);
+
+    FUZZ_dataProducer_free(producer);
+
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/block_round_trip.c

@@ -0,0 +1,103 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress),
+ * compares the result with the original, and calls abort() on corruption.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+#include "fuzz_third_party_seq_prod.h"
+
+static ZSTD_CCtx *cctx = NULL;
+static ZSTD_DCtx *dctx = NULL;
+static void* cBuf = NULL;
+static void* rBuf = NULL;
+static size_t bufSize = 0;
+
+static size_t roundTripTest(void *result, size_t resultCapacity,
+                            void *compressed, size_t compressedCapacity,
+                            const void *src, size_t srcSize,
+                            int cLevel)
+{
+    ZSTD_parameters const params = ZSTD_getParams(cLevel, srcSize, 0);
+    size_t ret = ZSTD_compressBegin_advanced(cctx, NULL, 0, params, srcSize);
+    FUZZ_ZASSERT(ret);
+
+    ret = ZSTD_compressBlock(cctx, compressed, compressedCapacity, src, srcSize);
+    FUZZ_ZASSERT(ret);
+    if (ret == 0) {
+        FUZZ_ASSERT(resultCapacity >= srcSize);
+        if (srcSize > 0) {
+            memcpy(result, src, srcSize);
+        }
+        return srcSize;
+    }
+    ZSTD_decompressBegin(dctx);
+    return ZSTD_decompressBlock(dctx, result, resultCapacity, compressed, ret);
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_SEQ_PROD_SETUP();
+
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    int const cLevel = FUZZ_dataProducer_int32Range(producer, kMinClevel, kMaxClevel);
+
+    size_t neededBufSize = size;
+    if (size > ZSTD_BLOCKSIZE_MAX)
+        size = ZSTD_BLOCKSIZE_MAX;
+
+    /* Allocate all buffers and contexts if not already allocated */
+    if (neededBufSize > bufSize || !cBuf || !rBuf) {
+        free(cBuf);
+        free(rBuf);
+        cBuf = FUZZ_malloc(neededBufSize);
+        rBuf = FUZZ_malloc(neededBufSize);
+        bufSize = neededBufSize;
+    }
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    {
+        size_t const result =
+            roundTripTest(rBuf, neededBufSize, cBuf, neededBufSize, src, size,
+              cLevel);
+        FUZZ_ZASSERT(result);
+        FUZZ_ASSERT_MSG(result == size, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
+    }
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    FUZZ_SEQ_PROD_TEARDOWN();
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/decompress_cross_format.c

@@ -0,0 +1,130 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+// This fuzz target validates decompression of magicless-format compressed data.
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#define ZSTD_STATIC_LINKING_ONLY
+#include "zstd.h"
+#include "fuzz_data_producer.h"
+
+static ZSTD_DCtx *dctx = NULL;
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    // Give a random portion of src data to the producer, to use for parameter generation.
+    // The rest will be interpreted as magicless compressed data.
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size_t magiclessSize = FUZZ_dataProducer_reserveDataPrefix(producer);
+    const uint8_t* const magiclessSrc = src;
+    size_t const dstSize = FUZZ_dataProducer_uint32Range(producer, 0, 10 * size);
+    uint8_t* const standardDst = (uint8_t*)FUZZ_malloc(dstSize);
+    uint8_t* const magiclessDst = (uint8_t*)FUZZ_malloc(dstSize);
+
+    // Create standard-format src from magicless-format src
+    const uint32_t zstd_magic = ZSTD_MAGICNUMBER;
+    size_t standardSize = sizeof(zstd_magic) + magiclessSize;
+    uint8_t* const standardSrc = (uint8_t*)FUZZ_malloc(standardSize);
+    memcpy(standardSrc, &zstd_magic, sizeof(zstd_magic)); // assume fuzzing on little-endian machine
+    memcpy(standardSrc + sizeof(zstd_magic), magiclessSrc, magiclessSize);
+
+    // Truncate to a single frame
+    {
+        const size_t standardFrameCompressedSize = ZSTD_findFrameCompressedSize(standardSrc, standardSize);
+        if (ZSTD_isError(standardFrameCompressedSize)) {
+            goto cleanup_and_return;
+        }
+        standardSize = standardFrameCompressedSize;
+        magiclessSize = standardFrameCompressedSize - sizeof(zstd_magic);
+    }
+
+    // Create DCtx if needed
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    // Test one-shot decompression
+    {
+        FUZZ_ZASSERT(ZSTD_DCtx_reset(dctx, ZSTD_reset_session_and_parameters));
+        FUZZ_ZASSERT(ZSTD_DCtx_setParameter(dctx, ZSTD_d_format, ZSTD_f_zstd1));
+        const size_t standardRet = ZSTD_decompressDCtx(
+                                        dctx, standardDst, dstSize, standardSrc, standardSize);
+
+        FUZZ_ZASSERT(ZSTD_DCtx_reset(dctx, ZSTD_reset_session_and_parameters));
+        FUZZ_ZASSERT(ZSTD_DCtx_setParameter(dctx, ZSTD_d_format, ZSTD_f_zstd1_magicless));
+        const size_t magiclessRet = ZSTD_decompressDCtx(
+                                        dctx, magiclessDst, dstSize, magiclessSrc, magiclessSize);
+
+        // Standard accepts => magicless should accept
+        if (!ZSTD_isError(standardRet)) FUZZ_ZASSERT(magiclessRet);
+
+        // Magicless accepts => standard should accept
+        // NOTE: this is nice-to-have, please disable this check if it is difficult to satisfy.
+        if (!ZSTD_isError(magiclessRet)) FUZZ_ZASSERT(standardRet);
+
+        // If both accept, decompressed size and data should match
+        if (!ZSTD_isError(standardRet) && !ZSTD_isError(magiclessRet)) {
+            FUZZ_ASSERT(standardRet == magiclessRet);
+            if (standardRet > 0) {
+                FUZZ_ASSERT(
+                    memcmp(standardDst, magiclessDst, standardRet) == 0
+                );
+            }
+        }
+    }
+
+    // Test streaming decompression
+    {
+        ZSTD_inBuffer standardIn = { standardSrc, standardSize, 0 };
+        ZSTD_inBuffer magiclessIn = { magiclessSrc, magiclessSize, 0 };
+        ZSTD_outBuffer standardOut = { standardDst, dstSize, 0 };
+        ZSTD_outBuffer magiclessOut = { magiclessDst, dstSize, 0 };
+
+        FUZZ_ZASSERT(ZSTD_DCtx_reset(dctx, ZSTD_reset_session_and_parameters));
+        FUZZ_ZASSERT(ZSTD_DCtx_setParameter(dctx, ZSTD_d_format, ZSTD_f_zstd1));
+        const size_t standardRet = ZSTD_decompressStream(dctx, &standardOut, &standardIn);
+
+        FUZZ_ZASSERT(ZSTD_DCtx_reset(dctx, ZSTD_reset_session_and_parameters));
+        FUZZ_ZASSERT(ZSTD_DCtx_setParameter(dctx, ZSTD_d_format, ZSTD_f_zstd1_magicless));
+        const size_t magiclessRet = ZSTD_decompressStream(dctx, &magiclessOut, &magiclessIn);
+
+        // Standard accepts => magicless should accept
+        if (standardRet == 0) FUZZ_ASSERT(magiclessRet == 0);
+
+        // Magicless accepts => standard should accept
+        // NOTE: this is nice-to-have, please disable this check if it is difficult to satisfy.
+        if (magiclessRet == 0) FUZZ_ASSERT(standardRet == 0);
+
+        // If both accept, decompressed size and data should match
+        if (standardRet == 0 && magiclessRet == 0) {
+            FUZZ_ASSERT(standardOut.pos == magiclessOut.pos);
+            if (standardOut.pos > 0) {
+                FUZZ_ASSERT(
+                    memcmp(standardOut.dst, magiclessOut.dst, standardOut.pos) == 0
+                );
+            }
+        }
+    }
+
+cleanup_and_return:
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    free(standardSrc);
+    free(standardDst);
+    free(magiclessDst);
+    FUZZ_dataProducer_free(producer);
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/decompress_dstSize_tooSmall.c

@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target attempts to decompress a valid compressed frame into
+ * an output buffer that is too small to ensure we always get
+ * ZSTD_error_dstSize_tooSmall.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "fuzz_helpers.h"
+#include "zstd.h"
+#include "zstd_errors.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+#include "fuzz_third_party_seq_prod.h"
+
+static ZSTD_CCtx *cctx = NULL;
+static ZSTD_DCtx *dctx = NULL;
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_SEQ_PROD_SETUP();
+
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size_t rBufSize = FUZZ_dataProducer_uint32Range(producer, 0, size);
+    size = FUZZ_dataProducer_remainingBytes(producer);
+    /* Ensure the round-trip buffer is too small. */
+    if (rBufSize >= size) {
+        rBufSize = size > 0 ? size - 1 : 0;
+    }
+    size_t const cBufSize = ZSTD_compressBound(size);
+
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    void *cBuf = FUZZ_malloc(cBufSize);
+    void *rBuf = FUZZ_malloc(rBufSize);
+    size_t const cSize = ZSTD_compressCCtx(cctx, cBuf, cBufSize, src, size, 1);
+    FUZZ_ZASSERT(cSize);
+    size_t const rSize = ZSTD_decompressDCtx(dctx, rBuf, rBufSize, cBuf, cSize);
+    if (size == 0) {
+        FUZZ_ASSERT(rSize == 0);
+    } else {
+        FUZZ_ASSERT(ZSTD_isError(rSize));
+        FUZZ_ASSERT(ZSTD_getErrorCode(rSize) == ZSTD_error_dstSize_tooSmall);
+    }
+    free(cBuf);
+    free(rBuf);
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    FUZZ_SEQ_PROD_TEARDOWN();
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/dictionary_decompress.c

@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target attempts to decompress the fuzzed data with the dictionary
+ * decompression function to ensure the decompressor never crashes. It does not
+ * fuzz the dictionary.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+#include "fuzz_third_party_seq_prod.h"
+
+static ZSTD_DCtx *dctx = NULL;
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_SEQ_PROD_SETUP();
+
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    FUZZ_dict_t dict;
+    ZSTD_DDict* ddict = NULL;
+
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+    dict = FUZZ_train(src, size, producer);
+    if (FUZZ_dataProducer_uint32Range(producer, 0, 1) == 0) {
+        ddict = ZSTD_createDDict(dict.buff, dict.size);
+        FUZZ_ASSERT(ddict);
+    } else {
+        if (FUZZ_dataProducer_uint32Range(producer, 0, 1) == 0)
+            FUZZ_ZASSERT(ZSTD_DCtx_loadDictionary_advanced(
+                dctx, dict.buff, dict.size,
+                (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+                (ZSTD_dictContentType_e)FUZZ_dataProducer_uint32Range(producer, 0, 2)));
+        else
+            FUZZ_ZASSERT(ZSTD_DCtx_refPrefix_advanced(
+                dctx, dict.buff, dict.size,
+                (ZSTD_dictContentType_e)FUZZ_dataProducer_uint32Range(producer, 0, 2)));
+    }
+
+    {
+        size_t const bufSize = FUZZ_dataProducer_uint32Range(producer, 0, 10 * size);
+        void* rBuf = FUZZ_malloc(bufSize);
+        if (ddict) {
+            ZSTD_decompress_usingDDict(dctx, rBuf, bufSize, src, size, ddict);
+        } else {
+            ZSTD_decompressDCtx(dctx, rBuf, bufSize, src, size);
+        }
+        free(rBuf);
+    }
+    free(dict.buff);
+    FUZZ_dataProducer_free(producer);
+    ZSTD_freeDDict(ddict);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    FUZZ_SEQ_PROD_TEARDOWN();
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/dictionary_loader.c

@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target makes sure that whenever a compression dictionary can be
+ * loaded, the data can be round tripped.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+#include "fuzz_third_party_seq_prod.h"
+
+/**
+ * Compresses the data and returns the compressed size or an error.
+ */
+static size_t compress(void* compressed, size_t compressedCapacity,
+                       void const* source, size_t sourceSize,
+                       void const* dict, size_t dictSize,
+                       ZSTD_dictLoadMethod_e dictLoadMethod,
+                       ZSTD_dictContentType_e dictContentType,
+                       int const refPrefix)
+{
+    ZSTD_CCtx* cctx = ZSTD_createCCtx();
+    if (refPrefix)
+        FUZZ_ZASSERT(ZSTD_CCtx_refPrefix_advanced(
+            cctx, dict, dictSize, dictContentType));
+    else
+        FUZZ_ZASSERT(ZSTD_CCtx_loadDictionary_advanced(
+            cctx, dict, dictSize, dictLoadMethod, dictContentType));
+    size_t const compressedSize = ZSTD_compress2(
+            cctx, compressed, compressedCapacity, source, sourceSize);
+    ZSTD_freeCCtx(cctx);
+    return compressedSize;
+}
+
+static size_t decompress(void* result, size_t resultCapacity,
+                         void const* compressed, size_t compressedSize,
+                         void const* dict, size_t dictSize,
+                       ZSTD_dictLoadMethod_e dictLoadMethod,
+                         ZSTD_dictContentType_e dictContentType,
+                         int const refPrefix)
+{
+    ZSTD_DCtx* dctx = ZSTD_createDCtx();
+    if (refPrefix)
+        FUZZ_ZASSERT(ZSTD_DCtx_refPrefix_advanced(
+            dctx, dict, dictSize, dictContentType));
+    else
+        FUZZ_ZASSERT(ZSTD_DCtx_loadDictionary_advanced(
+            dctx, dict, dictSize, dictLoadMethod, dictContentType));
+    size_t const resultSize = ZSTD_decompressDCtx(
+            dctx, result, resultCapacity, compressed, compressedSize);
+    FUZZ_ZASSERT(resultSize);
+    ZSTD_freeDCtx(dctx);
+    return resultSize;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_SEQ_PROD_SETUP();
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    int const refPrefix = FUZZ_dataProducer_uint32Range(producer, 0, 1) != 0;
+    ZSTD_dictLoadMethod_e const dlm =
+    size = FUZZ_dataProducer_uint32Range(producer, 0, 1);
+    ZSTD_dictContentType_e const dct =
+            FUZZ_dataProducer_uint32Range(producer, 0, 2);
+    size = FUZZ_dataProducer_remainingBytes(producer);
+
+    DEBUGLOG(4, "Dict load method %d", dlm);
+    DEBUGLOG(4, "Dict content type %d", dct);
+    DEBUGLOG(4, "Dict size %u", (unsigned)size);
+
+    void* const rBuf = FUZZ_malloc(size);
+    size_t const cBufSize = ZSTD_compressBound(size);
+    void* const cBuf = FUZZ_malloc(cBufSize);
+
+    size_t const cSize =
+            compress(cBuf, cBufSize, src, size, src, size, dlm, dct, refPrefix);
+    /* compression failing is okay */
+    if (ZSTD_isError(cSize)) {
+      FUZZ_ASSERT_MSG(dct != ZSTD_dct_rawContent, "Raw must always succeed!");
+      goto out;
+    }
+    size_t const rSize =
+            decompress(rBuf, size, cBuf, cSize, src, size, dlm, dct, refPrefix);
+    FUZZ_ASSERT_MSG(rSize == size, "Incorrect regenerated size");
+    FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
+
+out:
+    free(cBuf);
+    free(rBuf);
+    FUZZ_dataProducer_free(producer);
+    FUZZ_SEQ_PROD_TEARDOWN();
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/dictionary_round_trip.c

@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress) with
+ * a dictionary, compares the result with the original, and calls abort() on
+ * corruption.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+#include "fuzz_third_party_seq_prod.h"
+
+static ZSTD_CCtx* cctx = NULL;
+static ZSTD_DCtx* dctx = NULL;
+
+static size_t roundTripTest(void* result, size_t resultCapacity,
+                            void* compressed, size_t compressedCapacity,
+                            const void* src, size_t srcSize,
+                            FUZZ_dataProducer_t* producer)
+{
+    ZSTD_dictContentType_e dictContentType = ZSTD_dct_auto;
+    FUZZ_dict_t dict = FUZZ_train(src, srcSize, producer);
+    int const refPrefix = FUZZ_dataProducer_uint32Range(producer, 0, 1) != 0;
+    size_t cSize;
+    if (FUZZ_dataProducer_uint32Range(producer, 0, 15) == 0) {
+        int const cLevel = FUZZ_dataProducer_int32Range(producer, kMinClevel, kMaxClevel);
+
+        cSize = ZSTD_compress_usingDict(cctx,
+                compressed, compressedCapacity,
+                src, srcSize,
+                dict.buff, dict.size,
+                cLevel);
+        FUZZ_ZASSERT(cSize);
+        // Compress a second time and check for determinism
+        {
+            size_t const cSize0 = cSize;
+            XXH64_hash_t const hash0 = XXH64(compressed, cSize, 0);
+            cSize = ZSTD_compress_usingDict(cctx,
+                    compressed, compressedCapacity,
+                    src, srcSize,
+                    dict.buff, dict.size,
+                    cLevel);
+            FUZZ_ASSERT(cSize == cSize0);
+            FUZZ_ASSERT(XXH64(compressed, cSize, 0) == hash0);
+        }
+    } else {
+        size_t remainingBytes;
+        dictContentType = FUZZ_dataProducer_uint32Range(producer, 0, 2);
+        remainingBytes = FUZZ_dataProducer_remainingBytes(producer);
+        FUZZ_setRandomParameters(cctx, srcSize, producer);
+        /* Disable checksum so we can use sizes smaller than compress bound. */
+        FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 0));
+        if (refPrefix)
+            FUZZ_ZASSERT(ZSTD_CCtx_refPrefix_advanced(
+                cctx, dict.buff, dict.size,
+                dictContentType));
+        else
+            FUZZ_ZASSERT(ZSTD_CCtx_loadDictionary_advanced(
+                cctx, dict.buff, dict.size,
+                (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+                dictContentType));
+        cSize = ZSTD_compress2(cctx, compressed, compressedCapacity, src, srcSize);
+        FUZZ_ZASSERT(cSize);
+        // Compress a second time and check for determinism
+        {
+            size_t const cSize0 = cSize;
+            XXH64_hash_t const hash0 = XXH64(compressed, cSize, 0);
+            FUZZ_dataProducer_rollBack(producer, remainingBytes);
+            FUZZ_setRandomParameters(cctx, srcSize, producer);
+            FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 0));
+            if (refPrefix)
+                FUZZ_ZASSERT(ZSTD_CCtx_refPrefix_advanced(
+                    cctx, dict.buff, dict.size,
+                    dictContentType));
+            cSize = ZSTD_compress2(cctx, compressed, compressedCapacity, src, srcSize);
+            FUZZ_ASSERT(cSize == cSize0);
+            FUZZ_ASSERT(XXH64(compressed, cSize, 0) == hash0);
+        }
+    }
+    if (refPrefix)
+        FUZZ_ZASSERT(ZSTD_DCtx_refPrefix_advanced(
+            dctx, dict.buff, dict.size,
+            dictContentType));
+    else
+        FUZZ_ZASSERT(ZSTD_DCtx_loadDictionary_advanced(
+            dctx, dict.buff, dict.size,
+            (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+            dictContentType));
+    {
+        size_t const ret = ZSTD_decompressDCtx(
+                dctx, result, resultCapacity, compressed, cSize);
+        free(dict.buff);
+        return ret;
+    }
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_SEQ_PROD_SETUP();
+
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    size_t const rBufSize = size;
+    void* rBuf = FUZZ_malloc(rBufSize);
+    size_t cBufSize = ZSTD_compressBound(size);
+    void *cBuf;
+    /* Half of the time fuzz with a 1 byte smaller output size.
+     * This will still succeed because we force the checksum to be disabled,
+     * giving us 4 bytes of overhead.
+     */
+    cBufSize -= FUZZ_dataProducer_uint32Range(producer, 0, 1);
+    cBuf = FUZZ_malloc(cBufSize);
+
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    {
+        size_t const result =
+            roundTripTest(rBuf, rBufSize, cBuf, cBufSize, src, size, producer);
+        FUZZ_ZASSERT(result);
+        FUZZ_ASSERT_MSG(result == size, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
+    }
+    free(rBuf);
+    free(cBuf);
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    FUZZ_SEQ_PROD_TEARDOWN();
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/dictionary_stream_round_trip.c

@@ -0,0 +1,209 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress),
+ * compares the result with the original, and calls abort() on corruption.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+#include "fuzz_third_party_seq_prod.h"
+
+ZSTD_CCtx *cctx = NULL;
+static ZSTD_DCtx *dctx = NULL;
+static uint8_t* cBuf = NULL;
+static uint8_t* rBuf = NULL;
+static size_t bufSize = 0;
+
+static ZSTD_outBuffer makeOutBuffer(uint8_t *dst, size_t capacity,
+                                    FUZZ_dataProducer_t *producer)
+{
+    ZSTD_outBuffer buffer = { dst, 0, 0 };
+
+    FUZZ_ASSERT(capacity > 0);
+    buffer.size = (FUZZ_dataProducer_uint32Range(producer, 1, capacity));
+    FUZZ_ASSERT(buffer.size <= capacity);
+
+    return buffer;
+}
+
+static ZSTD_inBuffer makeInBuffer(const uint8_t **src, size_t *size,
+                                  FUZZ_dataProducer_t *producer)
+{
+    ZSTD_inBuffer buffer = { *src, 0, 0 };
+
+    FUZZ_ASSERT(*size > 0);
+    buffer.size = (FUZZ_dataProducer_uint32Range(producer, 1, *size));
+    FUZZ_ASSERT(buffer.size <= *size);
+    *src += buffer.size;
+    *size -= buffer.size;
+
+    return buffer;
+}
+
+static size_t compress(uint8_t *dst, size_t capacity,
+                        const uint8_t *src, size_t srcSize,
+                        const uint8_t* dict, size_t dictSize,
+                        FUZZ_dataProducer_t *producer, int refPrefix,
+                        ZSTD_dictContentType_e dictContentType)
+{
+    size_t dstSize = 0;
+    ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
+    FUZZ_setRandomParameters(cctx, srcSize, producer);
+
+    /* Disable checksum so we can use sizes smaller than compress bound. */
+    FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 0));
+    if (refPrefix)
+        FUZZ_ZASSERT(ZSTD_CCtx_refPrefix_advanced(
+            cctx, dict, dictSize,
+            dictContentType));
+    else
+        FUZZ_ZASSERT(ZSTD_CCtx_loadDictionary_advanced(
+            cctx, dict, dictSize,
+            (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+            dictContentType));
+
+    while (srcSize > 0) {
+        ZSTD_inBuffer in = makeInBuffer(&src, &srcSize, producer);
+        /* Mode controls the action. If mode == -1 we pick a new mode */
+        int mode = -1;
+        while (in.pos < in.size || mode != -1) {
+            ZSTD_outBuffer out = makeOutBuffer(dst, capacity, producer);
+            /* Previous action finished, pick a new mode. */
+            if (mode == -1) mode = FUZZ_dataProducer_uint32Range(producer, 0, 9);
+            switch (mode) {
+                case 0: /* fall-through */
+                case 1: /* fall-through */
+                case 2: {
+                    size_t const ret =
+                        ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_flush);
+                    FUZZ_ZASSERT(ret);
+                    if (ret == 0)
+                        mode = -1;
+                    break;
+                }
+                case 3: {
+                    size_t ret =
+                        ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end);
+                    FUZZ_ZASSERT(ret);
+                    /* Reset the compressor when the frame is finished */
+                    if (ret == 0) {
+                        ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
+                        if (FUZZ_dataProducer_uint32Range(producer, 0, 7) == 0) {
+                            size_t const remaining = in.size - in.pos;
+                            FUZZ_setRandomParameters(cctx, remaining, producer);
+                        }
+                        mode = -1;
+                    }
+                    break;
+                }
+                case 4: {
+                    ZSTD_inBuffer nullIn = { NULL, 0, 0 };
+                    ZSTD_outBuffer nullOut = { NULL, 0, 0 };
+                    size_t const ret = ZSTD_compressStream2(cctx, &nullOut, &nullIn, ZSTD_e_continue);
+                    FUZZ_ZASSERT(ret);
+                }
+                /* fall-through */
+                default: {
+                    size_t const ret =
+                        ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_continue);
+                    FUZZ_ZASSERT(ret);
+                    mode = -1;
+                }
+            }
+            dst += out.pos;
+            dstSize += out.pos;
+            capacity -= out.pos;
+        }
+    }
+    for (;;) {
+        ZSTD_inBuffer in = {NULL, 0, 0};
+        ZSTD_outBuffer out = makeOutBuffer(dst, capacity, producer);
+        size_t const ret = ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end);
+        FUZZ_ZASSERT(ret);
+
+        dst += out.pos;
+        dstSize += out.pos;
+        capacity -= out.pos;
+        if (ret == 0)
+            break;
+    }
+    return dstSize;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_SEQ_PROD_SETUP();
+    size_t neededBufSize;
+
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    neededBufSize = ZSTD_compressBound(size) * 15;
+
+    /* Allocate all buffers and contexts if not already allocated */
+    if (neededBufSize > bufSize) {
+        free(cBuf);
+        free(rBuf);
+        cBuf = (uint8_t*)FUZZ_malloc(neededBufSize);
+        rBuf = (uint8_t*)FUZZ_malloc(neededBufSize);
+        bufSize = neededBufSize;
+    }
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    {
+        ZSTD_dictContentType_e dictContentType = FUZZ_dataProducer_uint32Range(producer, 0, 2);
+        FUZZ_dict_t dict = FUZZ_train(src, size, producer);
+        int const refPrefix = FUZZ_dataProducer_uint32Range(producer, 0, 1) != 0;
+
+        size_t const cSize = compress(cBuf, neededBufSize, src, size, dict.buff, dict.size, producer, refPrefix, dictContentType);
+
+        if (refPrefix)
+            FUZZ_ZASSERT(ZSTD_DCtx_refPrefix_advanced(
+                dctx, dict.buff, dict.size,
+                dictContentType));
+        else
+            FUZZ_ZASSERT(ZSTD_DCtx_loadDictionary_advanced(
+                dctx, dict.buff, dict.size,
+                (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+                dictContentType));
+        size_t const rSize =
+            ZSTD_decompressDCtx(dctx, rBuf, neededBufSize, cBuf, cSize);
+        FUZZ_ZASSERT(rSize);
+        FUZZ_ASSERT_MSG(rSize == size, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
+        free(dict.buff);
+    }
+
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    FUZZ_SEQ_PROD_TEARDOWN();
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/fse_read_ncount.c

@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target round trips the FSE normalized count with FSE_writeNCount()
+ * and FSE_readNcount() to ensure that it can always round trip correctly.
+ */
+
+#define FSE_STATIC_LINKING_ONLY
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+#include "fse.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+
+    /* Pick a random tableLog and maxSymbolValue */
+    unsigned const tableLog = FUZZ_dataProducer_uint32Range(producer, FSE_MIN_TABLELOG, FSE_MAX_TABLELOG);
+    unsigned const maxSymbolValue = FUZZ_dataProducer_uint32Range(producer, 0, 255);
+
+    unsigned remainingWeight = (1u << tableLog) - 1;
+    size_t dataSize;
+    BYTE data[512];
+    short ncount[256];
+
+    /* Randomly fill the normalized count */
+    memset(ncount, 0, sizeof(ncount));
+    {
+        unsigned s;
+        for (s = 0; s < maxSymbolValue && remainingWeight > 0; ++s) {
+            short n = (short)FUZZ_dataProducer_int32Range(producer, -1, remainingWeight);
+            ncount[s] = n;
+            if (n < 0) {
+                remainingWeight -= 1;
+            } else {
+                assert((unsigned)n <= remainingWeight);
+                remainingWeight -= n;
+            }
+        }
+        /* Ensure ncount[maxSymbolValue] != 0 and the sum is (1<<tableLog) */
+        ncount[maxSymbolValue] = remainingWeight + 1;
+        if (ncount[maxSymbolValue] == 1 && FUZZ_dataProducer_uint32Range(producer, 0, 1) == 1) {
+            ncount[maxSymbolValue] = -1;
+        }
+    }
+    /* Write the normalized count */
+    {
+        FUZZ_ASSERT(sizeof(data) >= FSE_NCountWriteBound(maxSymbolValue, tableLog));
+        dataSize = FSE_writeNCount(data, sizeof(data), ncount, maxSymbolValue, tableLog);
+        FUZZ_ZASSERT(dataSize);
+    }
+    /* Read & validate the normalized count */
+    {
+        short rtNcount[256];
+        unsigned rtMaxSymbolValue = 255;
+        unsigned rtTableLog;
+        /* Copy into a buffer with a random amount of random data at the end */
+        size_t const buffSize = (size_t)FUZZ_dataProducer_uint32Range(producer, dataSize, sizeof(data));
+        BYTE* const buff = FUZZ_malloc(buffSize);
+        size_t rtDataSize;
+        memcpy(buff, data, dataSize); 
+        {
+            size_t b;
+            for (b = dataSize; b < buffSize; ++b) {
+                buff[b] = (BYTE)FUZZ_dataProducer_uint32Range(producer, 0, 255);
+            }
+        }
+
+        rtDataSize = FSE_readNCount(rtNcount, &rtMaxSymbolValue, &rtTableLog, buff, buffSize);
+        FUZZ_ZASSERT(rtDataSize);
+        FUZZ_ASSERT(rtDataSize == dataSize);
+        FUZZ_ASSERT(rtMaxSymbolValue == maxSymbolValue);
+        FUZZ_ASSERT(rtTableLog == tableLog);
+        {
+            unsigned s;
+            for (s = 0; s <= maxSymbolValue; ++s) {
+                FUZZ_ASSERT(ncount[s] == rtNcount[s]);
+            }
+        }
+        free(buff);
+    }
+
+    FUZZ_dataProducer_free(producer);
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/fuzz.h

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * Fuzz target interface.
+ * Fuzz targets have some common parameters passed as macros during compilation.
+ * Check the documentation for each individual fuzzer for more parameters.
+ *
+ * @param STATEFUL_FUZZING:
+ *        Define this to reuse state between fuzzer runs. This can be useful to
+ *        test code paths which are only executed when contexts are reused.
+ *        WARNING: Makes reproducing crashes much harder.
+ *        Default: Not defined.
+ * @param DEBUGLEVEL:
+ *        This is a parameter for the zstd library. Defining `DEBUGLEVEL=1`
+ *        enables assert() statements in the zstd library. Higher levels enable
+ *        logging, so aren't recommended. Defining `DEBUGLEVEL=1` is
+ *        recommended.
+ * @param MEM_FORCE_MEMORY_ACCESS:
+ *        This flag controls how the zstd library accesses unaligned memory.
+ *        It can be undefined, or 0 through 2. If it is undefined, it selects
+ *        the method to use based on the compiler.
+ * @param FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+ *        This is the canonical flag to enable deterministic builds for fuzzing.
+ *        Changes to zstd for fuzzing are gated behind this define.
+ *        It is recommended to define this when building zstd for fuzzing.
+ * @param FUZZ_THIRD_PARTY_SEQ_PROD
+ *        This flag allows sequence producer plugin authors to replace the built-in
+ *        default sequence producer with their own code. If you are not a plugin
+ *        author, you should not define this flag. See the docs at
+ *        fuzz_third_party_seq_prod.h for more information.
+ */
+
+#ifndef FUZZ_H
+#define FUZZ_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

build_amd64/_deps/zstd-src/tests/fuzz/fuzz.py

@@ -0,0 +1,910 @@
+#!/usr/bin/env python
+
+# ################################################################
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under both the BSD-style license (found in the
+# LICENSE file in the root directory of this source tree) and the GPLv2 (found
+# in the COPYING file in the root directory of this source tree).
+# You may select, at your option, one of the above-listed licenses.
+# ##########################################################################
+
+import argparse
+import contextlib
+import os
+import re
+import shlex
+import shutil
+import subprocess
+import sys
+import tempfile
+
+
+def abs_join(a, *p):
+    return os.path.abspath(os.path.join(a, *p))
+
+
+class InputType(object):
+    RAW_DATA = 1
+    COMPRESSED_DATA = 2
+    DICTIONARY_DATA = 3
+
+
+class FrameType(object):
+    ZSTD = 1
+    BLOCK = 2
+
+
+class TargetInfo(object):
+    def __init__(self, input_type, frame_type=FrameType.ZSTD):
+        self.input_type = input_type
+        self.frame_type = frame_type
+
+
+# Constants
+FUZZ_DIR = os.path.abspath(os.path.dirname(__file__))
+CORPORA_DIR = abs_join(FUZZ_DIR, 'corpora')
+TARGET_INFO = {
+    'simple_round_trip': TargetInfo(InputType.RAW_DATA),
+    'stream_round_trip': TargetInfo(InputType.RAW_DATA),
+    'block_round_trip': TargetInfo(InputType.RAW_DATA, FrameType.BLOCK),
+    'simple_decompress': TargetInfo(InputType.COMPRESSED_DATA),
+    'stream_decompress': TargetInfo(InputType.COMPRESSED_DATA),
+    'block_decompress': TargetInfo(InputType.COMPRESSED_DATA, FrameType.BLOCK),
+    'dictionary_round_trip': TargetInfo(InputType.RAW_DATA),
+    'dictionary_decompress': TargetInfo(InputType.COMPRESSED_DATA),
+    'zstd_frame_info': TargetInfo(InputType.COMPRESSED_DATA),
+    'simple_compress': TargetInfo(InputType.RAW_DATA),
+    'dictionary_loader': TargetInfo(InputType.DICTIONARY_DATA),
+    'raw_dictionary_round_trip': TargetInfo(InputType.RAW_DATA),
+    'dictionary_stream_round_trip': TargetInfo(InputType.RAW_DATA),
+    'decompress_dstSize_tooSmall': TargetInfo(InputType.RAW_DATA),
+    'fse_read_ncount': TargetInfo(InputType.RAW_DATA),
+    'sequence_compression_api': TargetInfo(InputType.RAW_DATA),
+    'seekable_roundtrip': TargetInfo(InputType.RAW_DATA),
+    'huf_round_trip': TargetInfo(InputType.RAW_DATA),
+    'huf_decompress': TargetInfo(InputType.RAW_DATA),
+    'decompress_cross_format': TargetInfo(InputType.RAW_DATA),
+    'generate_sequences': TargetInfo(InputType.RAW_DATA),
+}
+TARGETS = list(TARGET_INFO.keys())
+ALL_TARGETS = TARGETS + ['all']
+FUZZ_RNG_SEED_SIZE = 4
+
+# Standard environment variables
+CC = os.environ.get('CC', 'cc')
+CXX = os.environ.get('CXX', 'c++')
+CPPFLAGS = os.environ.get('CPPFLAGS', '')
+CFLAGS = os.environ.get('CFLAGS', '-O3')
+CXXFLAGS = os.environ.get('CXXFLAGS', CFLAGS)
+LDFLAGS = os.environ.get('LDFLAGS', '')
+MFLAGS = os.environ.get('MFLAGS', '-j')
+THIRD_PARTY_SEQ_PROD_OBJ = os.environ.get('THIRD_PARTY_SEQ_PROD_OBJ', '')
+
+# Fuzzing environment variables
+LIB_FUZZING_ENGINE = os.environ.get('LIB_FUZZING_ENGINE', 'libregression.a')
+AFL_FUZZ = os.environ.get('AFL_FUZZ', 'afl-fuzz')
+DECODECORPUS = os.environ.get('DECODECORPUS',
+                              abs_join(FUZZ_DIR, '..', 'decodecorpus'))
+ZSTD = os.environ.get('ZSTD', abs_join(FUZZ_DIR, '..', '..', 'zstd'))
+
+# Sanitizer environment variables
+MSAN_EXTRA_CPPFLAGS = os.environ.get('MSAN_EXTRA_CPPFLAGS', '')
+MSAN_EXTRA_CFLAGS = os.environ.get('MSAN_EXTRA_CFLAGS', '')
+MSAN_EXTRA_CXXFLAGS = os.environ.get('MSAN_EXTRA_CXXFLAGS', '')
+MSAN_EXTRA_LDFLAGS = os.environ.get('MSAN_EXTRA_LDFLAGS', '')
+
+
+def create(r):
+    d = os.path.abspath(r)
+    if not os.path.isdir(d):
+        os.makedirs(d)
+    return d
+
+
+def check(r):
+    d = os.path.abspath(r)
+    if not os.path.isdir(d):
+        return None
+    return d
+
+
+@contextlib.contextmanager
+def tmpdir():
+    dirpath = tempfile.mkdtemp()
+    try:
+        yield dirpath
+    finally:
+        shutil.rmtree(dirpath, ignore_errors=True)
+
+
+def parse_targets(in_targets):
+    targets = set()
+    for target in in_targets:
+        if not target:
+            continue
+        if target == 'all':
+            targets = targets.union(TARGETS)
+        elif target in TARGETS:
+            targets.add(target)
+        else:
+            raise RuntimeError('{} is not a valid target'.format(target))
+    return list(targets)
+
+
+def targets_parser(args, description):
+    parser = argparse.ArgumentParser(prog=args.pop(0), description=description)
+    parser.add_argument(
+        'TARGET',
+        nargs='*',
+        type=str,
+        help='Fuzz target(s) to build {{{}}}'.format(', '.join(ALL_TARGETS)))
+    args, extra = parser.parse_known_args(args)
+    args.extra = extra
+
+    args.TARGET = parse_targets(args.TARGET)
+
+    return args
+
+
+def parse_env_flags(args, flags):
+    """
+    Look for flags set by environment variables.
+    """
+    san_flags = ','.join(re.findall('-fsanitize=((?:[a-z]+,?)+)', flags))
+    nosan_flags = ','.join(re.findall('-fno-sanitize=((?:[a-z]+,?)+)', flags))
+
+    def set_sanitizer(sanitizer, default, san, nosan):
+        if sanitizer in san and sanitizer in nosan:
+            raise RuntimeError('-fno-sanitize={s} and -fsanitize={s} passed'.
+                               format(s=sanitizer))
+        if sanitizer in san:
+            return True
+        if sanitizer in nosan:
+            return False
+        return default
+
+    san = set(san_flags.split(','))
+    nosan = set(nosan_flags.split(','))
+
+    args.asan = set_sanitizer('address', args.asan, san, nosan)
+    args.msan = set_sanitizer('memory', args.msan, san, nosan)
+    args.ubsan = set_sanitizer('undefined', args.ubsan, san, nosan)
+
+    args.sanitize = args.asan or args.msan or args.ubsan
+
+    return args
+
+
+def compiler_version(cc, cxx):
+    """
+    Determines the compiler and version.
+    Only works for clang and gcc.
+    """
+    cc_version_bytes = subprocess.check_output([cc, "--version"])
+    cxx_version_bytes = subprocess.check_output([cxx, "--version"])
+    compiler = None
+    version = None
+    print("{} --version:\n{}".format(cc, cc_version_bytes.decode('ascii')))
+    if b'clang' in cc_version_bytes:
+        assert(b'clang' in cxx_version_bytes)
+        compiler = 'clang'
+    elif b'gcc' in cc_version_bytes or b'GCC' in cc_version_bytes:
+        assert(b'gcc' in cxx_version_bytes or b'g++' in cxx_version_bytes)
+        compiler = 'gcc'
+    if compiler is not None:
+        version_regex = b'([0-9]+)\.([0-9]+)\.([0-9]+)'
+        version_match = re.search(version_regex, cc_version_bytes)
+        version = tuple(int(version_match.group(i)) for i in range(1, 4))
+    return compiler, version
+
+
+def overflow_ubsan_flags(cc, cxx):
+    compiler, version = compiler_version(cc, cxx)
+    if compiler == 'gcc' and version < (8, 0, 0):
+        return ['-fno-sanitize=signed-integer-overflow']
+    if compiler == 'gcc' or (compiler == 'clang' and version >= (5, 0, 0)):
+        return ['-fno-sanitize=pointer-overflow']
+    return []
+
+
+def build_parser(args):
+    description = """
+    Cleans the repository and builds a fuzz target (or all).
+    Many flags default to environment variables (default says $X='y').
+    Options that aren't enabling features default to the correct values for
+    zstd.
+    Enable sanitizers with --enable-*san.
+    For regression testing just build.
+    For libFuzzer set LIB_FUZZING_ENGINE and pass --enable-coverage.
+    For AFL set CC and CXX to AFL's compilers and set
+    LIB_FUZZING_ENGINE='libregression.a'.
+    """
+    parser = argparse.ArgumentParser(prog=args.pop(0), description=description)
+    parser.add_argument(
+        '--lib-fuzzing-engine',
+        dest='lib_fuzzing_engine',
+        type=str,
+        default=LIB_FUZZING_ENGINE,
+        help=('The fuzzing engine to use e.g. /path/to/libFuzzer.a '
+              "(default: $LIB_FUZZING_ENGINE='{})".format(LIB_FUZZING_ENGINE)))
+
+    fuzz_group = parser.add_mutually_exclusive_group()
+    fuzz_group.add_argument(
+        '--enable-coverage',
+        dest='coverage',
+        action='store_true',
+        help='Enable coverage instrumentation (-fsanitize-coverage)')
+    fuzz_group.add_argument(
+        '--enable-fuzzer',
+        dest='fuzzer',
+        action='store_true',
+        help=('Enable clang fuzzer (-fsanitize=fuzzer). When enabled '
+              'LIB_FUZZING_ENGINE is ignored')
+    )
+
+    parser.add_argument(
+        '--enable-asan', dest='asan', action='store_true', help='Enable UBSAN')
+    parser.add_argument(
+        '--enable-ubsan',
+        dest='ubsan',
+        action='store_true',
+        help='Enable UBSAN')
+    parser.add_argument(
+        '--disable-ubsan-pointer-overflow',
+        dest='ubsan_pointer_overflow',
+        action='store_false',
+        help='Disable UBSAN pointer overflow check (known failure)')
+    parser.add_argument(
+        '--enable-msan', dest='msan', action='store_true', help='Enable MSAN')
+    parser.add_argument(
+        '--enable-msan-track-origins', dest='msan_track_origins',
+        action='store_true', help='Enable MSAN origin tracking')
+    parser.add_argument(
+        '--msan-extra-cppflags',
+        dest='msan_extra_cppflags',
+        type=str,
+        default=MSAN_EXTRA_CPPFLAGS,
+        help="Extra CPPFLAGS for MSAN (default: $MSAN_EXTRA_CPPFLAGS='{}')".
+        format(MSAN_EXTRA_CPPFLAGS))
+    parser.add_argument(
+        '--msan-extra-cflags',
+        dest='msan_extra_cflags',
+        type=str,
+        default=MSAN_EXTRA_CFLAGS,
+        help="Extra CFLAGS for MSAN (default: $MSAN_EXTRA_CFLAGS='{}')".format(
+            MSAN_EXTRA_CFLAGS))
+    parser.add_argument(
+        '--msan-extra-cxxflags',
+        dest='msan_extra_cxxflags',
+        type=str,
+        default=MSAN_EXTRA_CXXFLAGS,
+        help="Extra CXXFLAGS for MSAN (default: $MSAN_EXTRA_CXXFLAGS='{}')".
+        format(MSAN_EXTRA_CXXFLAGS))
+    parser.add_argument(
+        '--msan-extra-ldflags',
+        dest='msan_extra_ldflags',
+        type=str,
+        default=MSAN_EXTRA_LDFLAGS,
+        help="Extra LDFLAGS for MSAN (default: $MSAN_EXTRA_LDFLAGS='{}')".
+        format(MSAN_EXTRA_LDFLAGS))
+    parser.add_argument(
+        '--enable-sanitize-recover',
+        dest='sanitize_recover',
+        action='store_true',
+        help='Non-fatal sanitizer errors where possible')
+    parser.add_argument(
+        '--debug',
+        dest='debug',
+        type=int,
+        default=1,
+        help='Set DEBUGLEVEL (default: 1)')
+    parser.add_argument(
+        '--force-memory-access',
+        dest='memory_access',
+        type=int,
+        default=0,
+        help='Set MEM_FORCE_MEMORY_ACCESS (default: 0)')
+    parser.add_argument(
+        '--fuzz-rng-seed-size',
+        dest='fuzz_rng_seed_size',
+        type=int,
+        default=4,
+        help='Set FUZZ_RNG_SEED_SIZE (default: 4)')
+    parser.add_argument(
+        '--disable-fuzzing-mode',
+        dest='fuzzing_mode',
+        action='store_false',
+        help='Do not define FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION')
+    parser.add_argument(
+        '--enable-stateful-fuzzing',
+        dest='stateful_fuzzing',
+        action='store_true',
+        help='Reuse contexts between runs (makes reproduction impossible)')
+    parser.add_argument(
+        '--custom-seq-prod',
+        dest='third_party_seq_prod_obj',
+        type=str,
+        default=THIRD_PARTY_SEQ_PROD_OBJ,
+        help='Path to an object file with symbols for fuzzing your sequence producer plugin.')
+    parser.add_argument(
+        '--cc',
+        dest='cc',
+        type=str,
+        default=CC,
+        help="CC (default: $CC='{}')".format(CC))
+    parser.add_argument(
+        '--cxx',
+        dest='cxx',
+        type=str,
+        default=CXX,
+        help="CXX (default: $CXX='{}')".format(CXX))
+    parser.add_argument(
+        '--cppflags',
+        dest='cppflags',
+        type=str,
+        default=CPPFLAGS,
+        help="CPPFLAGS (default: $CPPFLAGS='{}')".format(CPPFLAGS))
+    parser.add_argument(
+        '--cflags',
+        dest='cflags',
+        type=str,
+        default=CFLAGS,
+        help="CFLAGS (default: $CFLAGS='{}')".format(CFLAGS))
+    parser.add_argument(
+        '--cxxflags',
+        dest='cxxflags',
+        type=str,
+        default=CXXFLAGS,
+        help="CXXFLAGS (default: $CXXFLAGS='{}')".format(CXXFLAGS))
+    parser.add_argument(
+        '--ldflags',
+        dest='ldflags',
+        type=str,
+        default=LDFLAGS,
+        help="LDFLAGS (default: $LDFLAGS='{}')".format(LDFLAGS))
+    parser.add_argument(
+        '--mflags',
+        dest='mflags',
+        type=str,
+        default=MFLAGS,
+        help="Extra Make flags (default: $MFLAGS='{}')".format(MFLAGS))
+    parser.add_argument(
+        'TARGET',
+        nargs='*',
+        type=str,
+        help='Fuzz target(s) to build {{{}}}'.format(', '.join(ALL_TARGETS))
+    )
+    args = parser.parse_args(args)
+    args = parse_env_flags(args, ' '.join(
+        [args.cppflags, args.cflags, args.cxxflags, args.ldflags]))
+
+    # Check option sanity
+    if args.msan and (args.asan or args.ubsan):
+        raise RuntimeError('MSAN may not be used with any other sanitizers')
+    if args.msan_track_origins and not args.msan:
+        raise RuntimeError('--enable-msan-track-origins requires MSAN')
+    if args.sanitize_recover and not args.sanitize:
+        raise RuntimeError('--enable-sanitize-recover but no sanitizers used')
+
+    return args
+
+
+def build(args):
+    try:
+        args = build_parser(args)
+    except Exception as e:
+        print(e)
+        return 1
+    # The compilation flags we are setting
+    targets = args.TARGET
+    cc = args.cc
+    cxx = args.cxx
+    cppflags = shlex.split(args.cppflags)
+    cflags = shlex.split(args.cflags)
+    ldflags = shlex.split(args.ldflags)
+    cxxflags = shlex.split(args.cxxflags)
+    mflags = shlex.split(args.mflags)
+    # Flags to be added to both cflags and cxxflags
+    common_flags = [
+        '-Wno-error=declaration-after-statement',
+        '-Wno-error=c++-compat',
+        '-Wno-error=deprecated' # C files are sometimes compiled with CXX
+    ]
+
+    cppflags += [
+        '-DDEBUGLEVEL={}'.format(args.debug),
+        '-DMEM_FORCE_MEMORY_ACCESS={}'.format(args.memory_access),
+        '-DFUZZ_RNG_SEED_SIZE={}'.format(args.fuzz_rng_seed_size),
+    ]
+
+    # Set flags for options
+    assert not (args.fuzzer and args.coverage)
+    if args.coverage:
+        common_flags += [
+            '-fsanitize-coverage=trace-pc-guard,indirect-calls,trace-cmp'
+        ]
+    if args.fuzzer:
+        common_flags += ['-fsanitize=fuzzer']
+        args.lib_fuzzing_engine = ''
+
+    mflags += ['LIB_FUZZING_ENGINE={}'.format(args.lib_fuzzing_engine)]
+
+    if args.sanitize_recover:
+        recover_flags = ['-fsanitize-recover=all']
+    else:
+        recover_flags = ['-fno-sanitize-recover=all']
+    if args.sanitize:
+        common_flags += recover_flags
+
+    if args.msan:
+        msan_flags = ['-fsanitize=memory']
+        if args.msan_track_origins:
+            msan_flags += ['-fsanitize-memory-track-origins']
+        common_flags += msan_flags
+        # Append extra MSAN flags (it might require special setup)
+        cppflags += [args.msan_extra_cppflags]
+        cflags += [args.msan_extra_cflags]
+        cxxflags += [args.msan_extra_cxxflags]
+        ldflags += [args.msan_extra_ldflags]
+
+    if args.asan:
+        common_flags += ['-fsanitize=address']
+
+    if args.ubsan:
+        ubsan_flags = ['-fsanitize=undefined']
+        if not args.ubsan_pointer_overflow:
+            ubsan_flags += overflow_ubsan_flags(cc, cxx)
+        common_flags += ubsan_flags
+
+    if args.stateful_fuzzing:
+        cppflags += ['-DSTATEFUL_FUZZING']
+
+    if args.third_party_seq_prod_obj:
+        cppflags += ['-DFUZZ_THIRD_PARTY_SEQ_PROD']
+        mflags += ['THIRD_PARTY_SEQ_PROD_OBJ={}'.format(args.third_party_seq_prod_obj)]
+
+    if args.fuzzing_mode:
+        cppflags += ['-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION']
+
+    if args.lib_fuzzing_engine == 'libregression.a':
+        targets = ['libregression.a'] + targets
+
+    # Append the common flags
+    cflags += common_flags
+    cxxflags += common_flags
+
+    # Prepare the flags for Make
+    cc_str = "CC={}".format(cc)
+    cxx_str = "CXX={}".format(cxx)
+    cppflags_str = "CPPFLAGS={}".format(' '.join(cppflags))
+    cflags_str = "CFLAGS={}".format(' '.join(cflags))
+    cxxflags_str = "CXXFLAGS={}".format(' '.join(cxxflags))
+    ldflags_str = "LDFLAGS={}".format(' '.join(ldflags))
+
+    # Print the flags
+    print('MFLAGS={}'.format(' '.join(mflags)))
+    print(cc_str)
+    print(cxx_str)
+    print(cppflags_str)
+    print(cflags_str)
+    print(cxxflags_str)
+    print(ldflags_str)
+
+    # Clean and build
+    clean_cmd = ['make', 'clean'] + mflags
+    print(' '.join(clean_cmd))
+    subprocess.check_call(clean_cmd)
+    build_cmd = [
+        'make',
+        '-j',
+        cc_str,
+        cxx_str,
+        cppflags_str,
+        cflags_str,
+        cxxflags_str,
+        ldflags_str,
+    ] + mflags + targets
+    print(' '.join(build_cmd))
+    subprocess.check_call(build_cmd)
+    return 0
+
+
+def libfuzzer_parser(args):
+    description = """
+    Runs a libfuzzer binary.
+    Passes all extra arguments to libfuzzer.
+    The fuzzer should have been build with LIB_FUZZING_ENGINE pointing to
+    libFuzzer.a.
+    Generates output in the CORPORA directory, puts crashes in the ARTIFACT
+    directory, and takes extra input from the SEED directory.
+    To merge AFL's output pass the SEED as AFL's output directory and pass
+    '-merge=1'.
+    """
+    parser = argparse.ArgumentParser(prog=args.pop(0), description=description)
+    parser.add_argument(
+        '--corpora',
+        type=str,
+        help='Override the default corpora dir (default: {})'.format(
+            abs_join(CORPORA_DIR, 'TARGET')))
+    parser.add_argument(
+        '--artifact',
+        type=str,
+        help='Override the default artifact dir (default: {})'.format(
+            abs_join(CORPORA_DIR, 'TARGET-crash')))
+    parser.add_argument(
+        '--seed',
+        type=str,
+        help='Override the default seed dir (default: {})'.format(
+            abs_join(CORPORA_DIR, 'TARGET-seed')))
+    parser.add_argument(
+        'TARGET',
+        type=str,
+        help='Fuzz target(s) to build {{{}}}'.format(', '.join(TARGETS)))
+    args, extra = parser.parse_known_args(args)
+    args.extra = extra
+
+    if args.TARGET and args.TARGET not in TARGETS:
+        raise RuntimeError('{} is not a valid target'.format(args.TARGET))
+
+    return args
+
+
+def libfuzzer(target, corpora=None, artifact=None, seed=None, extra_args=None):
+    if corpora is None:
+        corpora = abs_join(CORPORA_DIR, target)
+    if artifact is None:
+        artifact = abs_join(CORPORA_DIR, '{}-crash'.format(target))
+    if seed is None:
+        seed = abs_join(CORPORA_DIR, '{}-seed'.format(target))
+    if extra_args is None:
+        extra_args = []
+
+    target = abs_join(FUZZ_DIR, target)
+
+    corpora = [create(corpora)]
+    artifact = create(artifact)
+    seed = check(seed)
+
+    corpora += [artifact]
+    if seed is not None:
+        corpora += [seed]
+
+    cmd = [target, '-artifact_prefix={}/'.format(artifact)]
+    cmd += corpora + extra_args
+    print(' '.join(cmd))
+    subprocess.check_call(cmd)
+
+
+def libfuzzer_cmd(args):
+    try:
+        args = libfuzzer_parser(args)
+    except Exception as e:
+        print(e)
+        return 1
+    libfuzzer(args.TARGET, args.corpora, args.artifact, args.seed, args.extra)
+    return 0
+
+
+def afl_parser(args):
+    description = """
+    Runs an afl-fuzz job.
+    Passes all extra arguments to afl-fuzz.
+    The fuzzer should have been built with CC/CXX set to the AFL compilers,
+    and with LIB_FUZZING_ENGINE='libregression.a'.
+    Takes input from CORPORA and writes output to OUTPUT.
+    Uses AFL_FUZZ as the binary (set from flag or environment variable).
+    """
+    parser = argparse.ArgumentParser(prog=args.pop(0), description=description)
+    parser.add_argument(
+        '--corpora',
+        type=str,
+        help='Override the default corpora dir (default: {})'.format(
+            abs_join(CORPORA_DIR, 'TARGET')))
+    parser.add_argument(
+        '--output',
+        type=str,
+        help='Override the default AFL output dir (default: {})'.format(
+            abs_join(CORPORA_DIR, 'TARGET-afl')))
+    parser.add_argument(
+        '--afl-fuzz',
+        type=str,
+        default=AFL_FUZZ,
+        help='AFL_FUZZ (default: $AFL_FUZZ={})'.format(AFL_FUZZ))
+    parser.add_argument(
+        'TARGET',
+        type=str,
+        help='Fuzz target(s) to build {{{}}}'.format(', '.join(TARGETS)))
+    args, extra = parser.parse_known_args(args)
+    args.extra = extra
+
+    if args.TARGET and args.TARGET not in TARGETS:
+        raise RuntimeError('{} is not a valid target'.format(args.TARGET))
+
+    if not args.corpora:
+        args.corpora = abs_join(CORPORA_DIR, args.TARGET)
+    if not args.output:
+        args.output = abs_join(CORPORA_DIR, '{}-afl'.format(args.TARGET))
+
+    return args
+
+
+def afl(args):
+    try:
+        args = afl_parser(args)
+    except Exception as e:
+        print(e)
+        return 1
+    target = abs_join(FUZZ_DIR, args.TARGET)
+
+    corpora = create(args.corpora)
+    output = create(args.output)
+
+    cmd = [args.afl_fuzz, '-i', corpora, '-o', output] + args.extra
+    cmd += [target, '@@']
+    print(' '.join(cmd))
+    subprocess.call(cmd)
+    return 0
+
+
+def regression(args):
+    try:
+        description = """
+        Runs one or more regression tests.
+        The fuzzer should have been built with
+        LIB_FUZZING_ENGINE='libregression.a'.
+        Takes input from CORPORA.
+        """
+        args = targets_parser(args, description)
+    except Exception as e:
+        print(e)
+        return 1
+    for target in args.TARGET:
+        corpora = create(abs_join(CORPORA_DIR, target))
+        target = abs_join(FUZZ_DIR, target)
+        cmd = [target, corpora]
+        print(' '.join(cmd))
+        subprocess.check_call(cmd)
+    return 0
+
+
+def gen_parser(args):
+    description = """
+    Generate a seed corpus appropriate for TARGET with data generated with
+    decodecorpus.
+    The fuzz inputs are prepended with a seed before the zstd data, so the
+    output of decodecorpus shouldn't be used directly.
+    Generates NUMBER samples prepended with FUZZ_RNG_SEED_SIZE random bytes and
+    puts the output in SEED.
+    DECODECORPUS is the decodecorpus binary, and must already be built.
+    """
+    parser = argparse.ArgumentParser(prog=args.pop(0), description=description)
+    parser.add_argument(
+        '--number',
+        '-n',
+        type=int,
+        default=100,
+        help='Number of samples to generate')
+    parser.add_argument(
+        '--max-size-log',
+        type=int,
+        default=18,
+        help='Maximum sample size to generate')
+    parser.add_argument(
+        '--seed',
+        type=str,
+        help='Override the default seed dir (default: {})'.format(
+            abs_join(CORPORA_DIR, 'TARGET-seed')))
+    parser.add_argument(
+        '--decodecorpus',
+        type=str,
+        default=DECODECORPUS,
+        help="decodecorpus binary (default: $DECODECORPUS='{}')".format(
+            DECODECORPUS))
+    parser.add_argument(
+        '--zstd',
+        type=str,
+        default=ZSTD,
+        help="zstd binary (default: $ZSTD='{}')".format(ZSTD))
+    parser.add_argument(
+        '--fuzz-rng-seed-size',
+        type=int,
+        default=4,
+        help="FUZZ_RNG_SEED_SIZE used for generate the samples (must match)"
+    )
+    parser.add_argument(
+        'TARGET',
+        type=str,
+        help='Fuzz target(s) to build {{{}}}'.format(', '.join(TARGETS)))
+    args, extra = parser.parse_known_args(args)
+    args.extra = extra
+
+    if args.TARGET and args.TARGET not in TARGETS:
+        raise RuntimeError('{} is not a valid target'.format(args.TARGET))
+
+    if not args.seed:
+        args.seed = abs_join(CORPORA_DIR, '{}-seed'.format(args.TARGET))
+
+    if not os.path.isfile(args.decodecorpus):
+        raise RuntimeError("{} is not a file run 'make -C {} decodecorpus'".
+                           format(args.decodecorpus, abs_join(FUZZ_DIR, '..')))
+
+    return args
+
+
+def gen(args):
+    try:
+        args = gen_parser(args)
+    except Exception as e:
+        print(e)
+        return 1
+
+    seed = create(args.seed)
+    with tmpdir() as compressed, tmpdir() as decompressed, tmpdir() as dict:
+        info = TARGET_INFO[args.TARGET]
+
+        if info.input_type == InputType.DICTIONARY_DATA:
+            number = max(args.number, 1000)
+        else:
+            number = args.number
+        cmd = [
+            args.decodecorpus,
+            '-n{}'.format(args.number),
+            '-p{}/'.format(compressed),
+            '-o{}'.format(decompressed),
+        ]
+
+        if info.frame_type == FrameType.BLOCK:
+            cmd += [
+                '--gen-blocks',
+                '--max-block-size-log={}'.format(min(args.max_size_log, 17))
+            ]
+        else:
+            cmd += ['--max-content-size-log={}'.format(args.max_size_log)]
+
+        print(' '.join(cmd))
+        subprocess.check_call(cmd)
+
+        if info.input_type == InputType.RAW_DATA:
+            print('using decompressed data in {}'.format(decompressed))
+            samples = decompressed
+        elif info.input_type == InputType.COMPRESSED_DATA:
+            print('using compressed data in {}'.format(compressed))
+            samples = compressed
+        else:
+            assert info.input_type == InputType.DICTIONARY_DATA
+            print('making dictionary data from {}'.format(decompressed))
+            samples = dict
+            min_dict_size_log = 9
+            max_dict_size_log = max(min_dict_size_log + 1, args.max_size_log)
+            for dict_size_log in range(min_dict_size_log, max_dict_size_log):
+                dict_size = 1 << dict_size_log
+                cmd = [
+                    args.zstd,
+                    '--train',
+                    '-r', decompressed,
+                    '--maxdict={}'.format(dict_size),
+                    '-o', abs_join(dict, '{}.zstd-dict'.format(dict_size))
+                ]
+                print(' '.join(cmd))
+                subprocess.check_call(cmd)
+
+        # Copy the samples over and prepend the RNG seeds
+        for name in os.listdir(samples):
+            samplename = abs_join(samples, name)
+            outname = abs_join(seed, name)
+            with open(samplename, 'rb') as sample:
+                with open(outname, 'wb') as out:
+                    CHUNK_SIZE = 131072
+                    chunk = sample.read(CHUNK_SIZE)
+                    while len(chunk) > 0:
+                        out.write(chunk)
+                        chunk = sample.read(CHUNK_SIZE)
+    return 0
+
+
+def minimize(args):
+    try:
+        description = """
+        Runs a libfuzzer fuzzer with -merge=1 to build a minimal corpus in
+        TARGET_seed_corpus. All extra args are passed to libfuzzer.
+        """
+        args = targets_parser(args, description)
+    except Exception as e:
+        print(e)
+        return 1
+
+    for target in args.TARGET:
+        # Merge the corpus + anything else into the seed_corpus
+        corpus = abs_join(CORPORA_DIR, target)
+        seed_corpus = abs_join(CORPORA_DIR, "{}_seed_corpus".format(target))
+        extra_args = [corpus, "-merge=1"] + args.extra
+        libfuzzer(target, corpora=seed_corpus, extra_args=extra_args)
+        seeds = set(os.listdir(seed_corpus))
+        # Copy all crashes directly into the seed_corpus if not already present
+        crashes = abs_join(CORPORA_DIR, '{}-crash'.format(target))
+        for crash in os.listdir(crashes):
+            if crash not in seeds:
+                shutil.copy(abs_join(crashes, crash), seed_corpus)
+                seeds.add(crash)
+
+
+def zip_cmd(args):
+    try:
+        description = """
+        Zips up the seed corpus.
+        """
+        args = targets_parser(args, description)
+    except Exception as e:
+        print(e)
+        return 1
+
+    for target in args.TARGET:
+        # Zip the seed_corpus
+        seed_corpus = abs_join(CORPORA_DIR, "{}_seed_corpus".format(target))
+        zip_file = "{}.zip".format(seed_corpus)
+        cmd = ["zip", "-r", "-q", "-j", "-9", zip_file, "."]
+        print(' '.join(cmd))
+        subprocess.check_call(cmd, cwd=seed_corpus)
+
+
+def list_cmd(args):
+    print("\n".join(TARGETS))
+
+
+def short_help(args):
+    name = args[0]
+    print("Usage: {} [OPTIONS] COMMAND [ARGS]...\n".format(name))
+
+
+def help(args):
+    short_help(args)
+    print("\tfuzzing helpers (select a command and pass -h for help)\n")
+    print("Options:")
+    print("\t-h, --help\tPrint this message")
+    print("")
+    print("Commands:")
+    print("\tbuild\t\tBuild a fuzzer")
+    print("\tlibfuzzer\tRun a libFuzzer fuzzer")
+    print("\tafl\t\tRun an AFL fuzzer")
+    print("\tregression\tRun a regression test")
+    print("\tgen\t\tGenerate a seed corpus for a fuzzer")
+    print("\tminimize\tMinimize the test corpora")
+    print("\tzip\t\tZip the minimized corpora up")
+    print("\tlist\t\tList the available targets")
+
+
+def main():
+    args = sys.argv
+    if len(args) < 2:
+        help(args)
+        return 1
+    if args[1] == '-h' or args[1] == '--help' or args[1] == '-H':
+        help(args)
+        return 1
+    command = args.pop(1)
+    args[0] = "{} {}".format(args[0], command)
+    if command == "build":
+        return build(args)
+    if command == "libfuzzer":
+        return libfuzzer_cmd(args)
+    if command == "regression":
+        return regression(args)
+    if command == "afl":
+        return afl(args)
+    if command == "gen":
+        return gen(args)
+    if command == "minimize":
+        return minimize(args)
+    if command == "zip":
+        return zip_cmd(args)
+    if command == "list":
+        return list_cmd(args)
+    short_help(args)
+    print("Error: No such command {} (pass -h for help)".format(command))
+    return 1
+
+
+if __name__ == "__main__":
+    sys.exit(main())

build_amd64/_deps/zstd-src/tests/fuzz/fuzz_data_producer.c

@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#include "fuzz_helpers.h"
+#include "fuzz_data_producer.h"
+
+struct FUZZ_dataProducer_s{
+  const uint8_t *data;
+  size_t size;
+};
+
+FUZZ_dataProducer_t *FUZZ_dataProducer_create(const uint8_t *data, size_t size) {
+    FUZZ_dataProducer_t *producer = FUZZ_malloc(sizeof(FUZZ_dataProducer_t));
+
+    producer->data = data;
+    producer->size = size;
+    return producer;
+}
+
+void FUZZ_dataProducer_free(FUZZ_dataProducer_t *producer) { free(producer); }
+
+uint32_t FUZZ_dataProducer_uint32Range(FUZZ_dataProducer_t *producer, uint32_t min,
+                                  uint32_t max) {
+    uint32_t range = max - min;
+    uint32_t rolling = range;
+    uint32_t result = 0;
+
+    FUZZ_ASSERT(min <= max);
+
+    while (rolling > 0 && producer->size > 0) {
+      uint8_t next = *(producer->data + producer->size - 1);
+      producer->size -= 1;
+      result = (result << 8) | next;
+      rolling >>= 8;
+    }
+
+    if (range == 0xffffffff) {
+      return result;
+    }
+
+    return min + result % (range + 1);
+}
+
+uint32_t FUZZ_dataProducer_uint32(FUZZ_dataProducer_t *producer) {
+    return FUZZ_dataProducer_uint32Range(producer, 0, 0xffffffff);
+}
+
+int32_t FUZZ_dataProducer_int32Range(FUZZ_dataProducer_t *producer,
+                                    int32_t min, int32_t max)
+{
+    FUZZ_ASSERT(min <= max);
+
+    if (min < 0)
+      return (int)FUZZ_dataProducer_uint32Range(producer, 0, max - min) + min;
+
+    return FUZZ_dataProducer_uint32Range(producer, min, max);
+}
+
+size_t FUZZ_dataProducer_remainingBytes(FUZZ_dataProducer_t *producer){
+    return producer->size;
+}
+
+void FUZZ_dataProducer_rollBack(FUZZ_dataProducer_t *producer, size_t remainingBytes)
+{
+    FUZZ_ASSERT(remainingBytes >= producer->size);
+    producer->size = remainingBytes;
+}
+
+int FUZZ_dataProducer_empty(FUZZ_dataProducer_t *producer) {
+    return producer->size == 0;
+}
+
+size_t FUZZ_dataProducer_contract(FUZZ_dataProducer_t *producer, size_t newSize)
+{
+    const size_t effectiveNewSize = newSize > producer->size ? producer->size : newSize;
+
+    size_t remaining = producer->size - effectiveNewSize;
+    producer->data = producer->data + remaining;
+    producer->size = effectiveNewSize;
+    return remaining;
+}
+
+size_t FUZZ_dataProducer_reserveDataPrefix(FUZZ_dataProducer_t *producer)
+{
+    size_t producerSliceSize = FUZZ_dataProducer_uint32Range(
+                                  producer, 0, producer->size);
+    return FUZZ_dataProducer_contract(producer, producerSliceSize);
+}

build_amd64/_deps/zstd-src/tests/fuzz/fuzz_data_producer.h

@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * Helper APIs for generating random data from input data stream.
+ The producer reads bytes from the end of the input and appends them together
+ to generate  a random number in the requested range. If it runs out of input
+ data, it will keep returning the same value (min) over and over again.
+
+ */
+
+#ifndef FUZZ_DATA_PRODUCER_H
+#define FUZZ_DATA_PRODUCER_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+
+/* Struct used for maintaining the state of the data */
+typedef struct FUZZ_dataProducer_s FUZZ_dataProducer_t;
+
+/* Returns a data producer state struct. Use for producer initialization. */
+FUZZ_dataProducer_t *FUZZ_dataProducer_create(const uint8_t *data, size_t size);
+
+/* Frees the data producer */
+void FUZZ_dataProducer_free(FUZZ_dataProducer_t *producer);
+
+/* Returns value between [min, max] */
+uint32_t FUZZ_dataProducer_uint32Range(FUZZ_dataProducer_t *producer, uint32_t min,
+                                  uint32_t max);
+
+/* Returns a uint32 value */
+uint32_t FUZZ_dataProducer_uint32(FUZZ_dataProducer_t *producer);
+
+/* Returns a signed value between [min, max] */
+int32_t FUZZ_dataProducer_int32Range(FUZZ_dataProducer_t *producer,
+                                    int32_t min, int32_t max);
+
+/* Returns the size of the remaining bytes of data in the producer */
+size_t FUZZ_dataProducer_remainingBytes(FUZZ_dataProducer_t *producer);
+
+/* Rolls back the data producer state to have remainingBytes remaining */
+void FUZZ_dataProducer_rollBack(FUZZ_dataProducer_t *producer, size_t remainingBytes);
+
+/* Returns true if the data producer is out of bytes */
+int FUZZ_dataProducer_empty(FUZZ_dataProducer_t *producer);
+
+/* Restricts the producer to only the last newSize bytes of data.
+If newSize > current data size, nothing happens. Returns the number of bytes
+the producer won't use anymore, after contracting. */
+size_t FUZZ_dataProducer_contract(FUZZ_dataProducer_t *producer, size_t newSize);
+
+/* Restricts the producer to use only the last X bytes of data, where X is
+ a random number in the interval [0, data_size]. Returns the size of the
+ remaining data the producer won't use anymore (the prefix). */
+size_t FUZZ_dataProducer_reserveDataPrefix(FUZZ_dataProducer_t *producer);
+#endif // FUZZ_DATA_PRODUCER_H

build_amd64/_deps/zstd-src/tests/fuzz/fuzz_helpers.c

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+#include "fuzz_helpers.h"
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+void* FUZZ_malloc(size_t size)
+{
+    if (size > 0) {
+        void* const mem = malloc(size);
+        FUZZ_ASSERT(mem);
+        return mem;
+    }
+    return NULL;
+}
+
+void* FUZZ_malloc_rand(size_t size, FUZZ_dataProducer_t *producer)
+{
+    if (size > 0) {
+        void* const mem = malloc(size);
+        FUZZ_ASSERT(mem);
+        return mem;
+    } else {
+        uintptr_t ptr = 0;
+        /* Add +- 1M 50% of the time */
+        if (FUZZ_dataProducer_uint32Range(producer, 0, 1))
+            FUZZ_dataProducer_int32Range(producer, -1000000, 1000000);
+        return (void*)ptr;
+    }
+
+}
+
+int FUZZ_memcmp(void const* lhs, void const* rhs, size_t size)
+{
+    if (size == 0) {
+        return 0;
+    }
+    return memcmp(lhs, rhs, size);
+}

build_amd64/_deps/zstd-src/tests/fuzz/fuzz_helpers.h

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * Helper functions for fuzzing.
+ */
+
+#ifndef FUZZ_HELPERS_H
+#define FUZZ_HELPERS_H
+
+#include "debug.h"
+#include "fuzz.h"
+#include "xxhash.h"
+#include "zstd.h"
+#include "fuzz_data_producer.h"
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+
+#define FUZZ_QUOTE_IMPL(str) #str
+#define FUZZ_QUOTE(str) FUZZ_QUOTE_IMPL(str)
+
+/**
+ * Asserts for fuzzing that are always enabled.
+ */
+#define FUZZ_ASSERT_MSG(cond, msg)                                             \
+  ((cond) ? (void)0                                                            \
+          : (fprintf(stderr, "%s: %u: Assertion: `%s' failed. %s\n", __FILE__, \
+                     __LINE__, FUZZ_QUOTE(cond), (msg)),                       \
+             abort()))
+#define FUZZ_ASSERT(cond) FUZZ_ASSERT_MSG((cond), "");
+#define FUZZ_ZASSERT(code)                                                     \
+  FUZZ_ASSERT_MSG(!ZSTD_isError(code), ZSTD_getErrorName(code))
+
+#if defined(__GNUC__)
+#define FUZZ_STATIC static __inline __attribute__((unused))
+#elif defined(__cplusplus) ||                                                  \
+    (defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
+#define FUZZ_STATIC static inline
+#elif defined(_MSC_VER)
+#define FUZZ_STATIC static __inline
+#else
+#define FUZZ_STATIC static
+#endif
+
+/**
+ * malloc except return NULL for zero sized data and FUZZ_ASSERT
+ * that malloc doesn't fail.
+ */
+void* FUZZ_malloc(size_t size);
+
+/**
+ * malloc except returns random pointer for zero sized data and FUZZ_ASSERT
+ * that malloc doesn't fail.
+ */
+void* FUZZ_malloc_rand(size_t size,  FUZZ_dataProducer_t *producer);
+
+/**
+ * memcmp but accepts NULL.
+ */
+int FUZZ_memcmp(void const* lhs, void const* rhs, size_t size);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

build_amd64/_deps/zstd-src/tests/fuzz/fuzz_third_party_seq_prod.h

@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) Yann Collet, Meta Platforms, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#ifndef EXAMPLE_SEQ_PROD_H
+#define EXAMPLE_SEQ_PROD_H
+
+#define ZSTD_STATIC_LINKING_ONLY
+#include "zstd.h"
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* *** INTERFACE FOR FUZZING THIRD-PARTY SEQUENCE PRODUCER PLUGINS ***
+ * Fuzz-testing for the external sequence producer API was introduced in PR #3437.
+ * However, the setup in #3437 only allows fuzzers to exercise the implementation of the
+ * API itself (the code in the core zstd library which interacts with your plugin).
+ *
+ * This header defines an interface for plugin authors to link their code into the fuzzer
+ * build. Plugin authors can provide an object file implementing the symbols below,
+ * and those symbols will replace the default ones provided by #3437.
+ *
+ * To fuzz your plugin, follow these steps:
+ *   - Build your object file with a recent version of clang. Building with gcc is not supported.
+ *   - Build your object file using appropriate flags for fuzzing. For example:
+ *     `-g -fno-omit-frame-pointer -fsanitize=undefined,address,fuzzer`
+ *   - Build the fuzzer binaries with options corresponding to the flags you chose. Use --custom-seq-prod= to pass in your object file:
+ *     `./fuzz.py build all --enable-fuzzer --enable-asan --enable-ubsan --cc clang --cxx clang++ --custom-seq-prod=your_object.o`
+ *
+ * An example implementation of this header is provided at tests/fuzz/seq_prod_fuzz_example/.
+ * Use these commands to fuzz with the example code:
+ *   $ make corpora
+ *   $ make -C seq_prod_fuzz_example/
+ *   $ python3 ./fuzz.py build all --enable-fuzzer --enable-asan --enable-ubsan --cc clang --cxx clang++ --custom-seq-prod=seq_prod_fuzz_example/example_seq_prod.o
+ *   $ python3 ./fuzz.py libfuzzer simple_round_trip
+ */
+
+/* The fuzzer will call this function before each test-case. It should run any
+ * setup actions (such as starting a hardware device) needed for fuzzing.
+ *
+ * The fuzzer will assert() that the return value is zero. To signal an error,
+ * please return a non-zero value. */
+size_t FUZZ_seqProdSetup(void);
+
+/* The fuzzer will call this function after each test-case. It should free
+ * resources acquired by FUZZ_seqProdSetup() to prevent leaks across test-cases.
+ *
+ * The fuzzer will assert() that the return value is zero. To signal an error,
+ * please return a non-zero value. */
+size_t FUZZ_seqProdTearDown(void);
+
+/* The fuzzer will call this function before each test-case, only after calling
+ * FUZZ_seqProdSetup(), to obtain a sequence producer state which can be passed
+ * into ZSTD_registerSequenceProducer().
+ *
+ * All compressions which are part of a test-case will share a single sequence
+ * producer state. Sharing the state object is safe because the fuzzers currently
+ * don't exercise the sequence producer API in multi-threaded scenarios. We may
+ * need a new approach in the future to support multi-threaded fuzzing.
+ *
+ * The fuzzer will assert() that the return value is not NULL. To signal an error,
+ * please return NULL. */
+void* FUZZ_createSeqProdState(void);
+
+/* The fuzzer will call this function after each test-case. It should free any
+ * resources acquired by FUZZ_createSeqProdState().
+ *
+ * The fuzzer will assert() that the return value is zero. To signal an error,
+ * please return a non-zero value. */
+size_t FUZZ_freeSeqProdState(void* sequenceProducerState);
+
+/* This is the sequence producer function you would like to fuzz! It will receive
+ * the void* returned by FUZZ_createSeqProdState() on each invocation. */
+size_t FUZZ_thirdPartySeqProd(void* sequenceProducerState,
+                              ZSTD_Sequence* outSeqs, size_t outSeqsCapacity,
+                              const void* src, size_t srcSize,
+                              const void* dict, size_t dictSize,
+                              int compressionLevel,
+                              size_t windowSize);
+
+/* These macros are internal helpers. You do not need to worry about them. */
+#ifdef FUZZ_THIRD_PARTY_SEQ_PROD
+#define FUZZ_SEQ_PROD_SETUP()                                                  \
+  do {                                                                         \
+    FUZZ_ASSERT(FUZZ_seqProdSetup() == 0);                                     \
+    FUZZ_seqProdState = FUZZ_createSeqProdState();                             \
+    FUZZ_ASSERT(FUZZ_seqProdState != NULL);                                    \
+  } while (0)
+#else
+#define FUZZ_SEQ_PROD_SETUP()
+#endif
+
+#ifdef FUZZ_THIRD_PARTY_SEQ_PROD
+#define FUZZ_SEQ_PROD_TEARDOWN()                                               \
+  do {                                                                         \
+    FUZZ_ASSERT(FUZZ_freeSeqProdState(FUZZ_seqProdState) == 0);                \
+    FUZZ_ASSERT(FUZZ_seqProdTearDown() == 0);                                  \
+  } while (0)
+#else
+#define FUZZ_SEQ_PROD_TEARDOWN()
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* EXAMPLE_SEQ_PROD_H */

build_amd64/_deps/zstd-src/tests/fuzz/generate_sequences.c

@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "fuzz_data_producer.h"
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+
+/**
+ * This fuzz target ensures that ZSTD_generateSequences() does not crash and
+ * if it succeeds that ZSTD_compressSequences() round trips.
+ */
+
+static void testRoundTrip(ZSTD_CCtx* cctx, ZSTD_Sequence const* seqs, size_t nbSeqs, const void* src, size_t srcSize) {
+  /* Compress the sequences with block delimiters */
+  const size_t compressBound = ZSTD_compressBound(srcSize);
+  void* dst = FUZZ_malloc(compressBound);
+  FUZZ_ASSERT(dst);
+
+  size_t compressedSize = ZSTD_compressSequences(cctx, dst, compressBound, seqs, nbSeqs, src, srcSize);
+  FUZZ_ZASSERT(compressedSize);
+
+  void* decompressed = FUZZ_malloc(srcSize);
+  FUZZ_ASSERT(srcSize == 0 || decompressed);
+  size_t decompressedSize = ZSTD_decompress(decompressed, srcSize, dst, compressedSize);
+  FUZZ_ZASSERT(decompressedSize);
+  FUZZ_ASSERT(decompressedSize == srcSize);
+  if (srcSize != 0) {
+    FUZZ_ASSERT(!memcmp(src, decompressed, srcSize));
+  }
+
+  free(decompressed);
+  free(dst);
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+
+  FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(data, size);
+  size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+  ZSTD_CCtx* cctx = ZSTD_createCCtx();
+  FUZZ_ASSERT(cctx);
+
+  const size_t seqsCapacity = FUZZ_dataProducer_uint32Range(producer, 0, 2 * ZSTD_sequenceBound(size));
+  ZSTD_Sequence* seqs = (ZSTD_Sequence*)FUZZ_malloc(sizeof(ZSTD_Sequence) * seqsCapacity);
+  FUZZ_ASSERT(seqsCapacity == 0 || seqs);
+
+  FUZZ_setRandomParameters(cctx, size, producer);
+  FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_targetCBlockSize, 0));
+  FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, 0));
+
+  const size_t nbSeqs = ZSTD_generateSequences(cctx, seqs, seqsCapacity, data, size);
+  if (ZSTD_isError(nbSeqs)) {
+    /* Allowed to error if the destination is too small */
+    if (ZSTD_getErrorCode(nbSeqs) == ZSTD_error_dstSize_tooSmall) {
+        FUZZ_ASSERT(seqsCapacity < ZSTD_sequenceBound(size));
+    }
+  } else {
+    /* Ensure we round trip with and without block delimiters*/
+
+    FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_blockDelimiters, ZSTD_sf_explicitBlockDelimiters));
+    testRoundTrip(cctx, seqs, nbSeqs, data, size);
+
+    const size_t nbMergedSeqs = ZSTD_mergeBlockDelimiters(seqs, nbSeqs);
+    FUZZ_ASSERT(nbMergedSeqs <= nbSeqs);
+    FUZZ_ZASSERT(ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only));
+    FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_blockDelimiters, ZSTD_sf_noBlockDelimiters));
+    testRoundTrip(cctx, seqs, nbMergedSeqs, data, size);
+  }
+
+  free(seqs);
+  ZSTD_freeCCtx(cctx);
+  FUZZ_dataProducer_free(producer);
+  return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/huf_decompress.c

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress),
+ * compares the result with the original, and calls abort() on corruption.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "common/cpu.h"
+#include "common/huf.h"
+#include "fuzz_helpers.h"
+#include "fuzz_data_producer.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    /* Select random parameters: #streams, X1 or X2 decoding, bmi2 */
+    int const streams = FUZZ_dataProducer_int32Range(producer, 0, 1);
+    int const symbols = FUZZ_dataProducer_int32Range(producer, 0, 1);
+    int const flags = 0
+        | (ZSTD_cpuid_bmi2(ZSTD_cpuid()) && FUZZ_dataProducer_int32Range(producer, 0, 1) ? HUF_flags_bmi2 : 0)
+        | (FUZZ_dataProducer_int32Range(producer, 0, 1) ? HUF_flags_optimalDepth : 0)
+        | (FUZZ_dataProducer_int32Range(producer, 0, 1) ? HUF_flags_preferRepeat : 0)
+        | (FUZZ_dataProducer_int32Range(producer, 0, 1) ? HUF_flags_suspectUncompressible : 0)
+        | (FUZZ_dataProducer_int32Range(producer, 0, 1) ? HUF_flags_disableAsm : 0)
+        | (FUZZ_dataProducer_int32Range(producer, 0, 1) ? HUF_flags_disableFast : 0);
+    /* Select a random cBufSize - it may be too small */
+    size_t const dBufSize = FUZZ_dataProducer_uint32Range(producer, 0, 8 * size + 500);
+    size_t const maxTableLog = FUZZ_dataProducer_uint32Range(producer, 1, HUF_TABLELOG_MAX);
+    HUF_DTable* dt = (HUF_DTable*)FUZZ_malloc(HUF_DTABLE_SIZE(maxTableLog) * sizeof(HUF_DTable));
+    size_t const wkspSize = HUF_WORKSPACE_SIZE;
+    void* wksp = FUZZ_malloc(wkspSize);
+    void* dBuf = FUZZ_malloc(dBufSize);
+    dt[0] = maxTableLog * 0x01000001;
+    size = FUZZ_dataProducer_remainingBytes(producer);
+
+    if (symbols == 0) {
+        size_t const err = HUF_readDTableX1_wksp(dt, src, size, wksp, wkspSize, flags);
+        if (ZSTD_isError(err))
+            goto _out;
+    } else {
+        size_t const err = HUF_readDTableX2_wksp(dt, src, size, wksp, wkspSize, flags);
+        if (ZSTD_isError(err))
+            goto _out;
+    }
+    if (streams == 0)
+        HUF_decompress1X_usingDTable(dBuf, dBufSize, src, size, dt, flags);
+    else
+        HUF_decompress4X_usingDTable(dBuf, dBufSize, src, size, dt, flags);
+
+_out:
+    free(dt);
+    free(wksp);
+    free(dBuf);
+    FUZZ_dataProducer_free(producer);
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/huf_round_trip.c

@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress),
+ * compares the result with the original, and calls abort() on corruption.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "common/cpu.h"
+#include "compress/hist.h"
+#include "common/huf.h"
+#include "fuzz_helpers.h"
+#include "fuzz_data_producer.h"
+#include "common/bits.h"
+
+static size_t adjustTableLog(size_t tableLog, size_t maxSymbol)
+{
+    size_t const alphabetSize = maxSymbol + 1;
+    size_t minTableLog = ZSTD_highbit32(alphabetSize) + 1;
+    if ((alphabetSize & (alphabetSize - 1)) != 0) {
+        ++minTableLog;
+    }
+    assert(minTableLog <= 9);
+    if (tableLog < minTableLog)
+        return minTableLog;
+    else
+        return tableLog;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    /* Select random parameters: #streams, X1 or X2 decoding, bmi2 */
+    int const streams = FUZZ_dataProducer_int32Range(producer, 0, 1);
+    int const symbols = FUZZ_dataProducer_int32Range(producer, 0, 1);
+    int const flags = 0
+        | (ZSTD_cpuid_bmi2(ZSTD_cpuid()) && FUZZ_dataProducer_int32Range(producer, 0, 1) ? HUF_flags_bmi2 : 0)
+        | (FUZZ_dataProducer_int32Range(producer, 0, 1) ? HUF_flags_optimalDepth : 0)
+        | (FUZZ_dataProducer_int32Range(producer, 0, 1) ? HUF_flags_preferRepeat : 0)
+        | (FUZZ_dataProducer_int32Range(producer, 0, 1) ? HUF_flags_suspectUncompressible : 0)
+        | (FUZZ_dataProducer_int32Range(producer, 0, 1) ? HUF_flags_disableAsm : 0)
+        | (FUZZ_dataProducer_int32Range(producer, 0, 1) ? HUF_flags_disableFast : 0);
+    /* Select a random cBufSize - it may be too small */
+    size_t const cBufSize = FUZZ_dataProducer_uint32Range(producer, 0, 4 * size);
+    /* Select a random tableLog - we'll adjust it up later */
+    size_t tableLog = FUZZ_dataProducer_uint32Range(producer, 1, 12);
+    size_t const kMaxSize = 256 * 1024;
+    size = FUZZ_dataProducer_remainingBytes(producer);
+    if (size > kMaxSize)
+        size = kMaxSize;
+
+    if (size <= 1) {
+        FUZZ_dataProducer_free(producer);
+        return 0;
+    }
+
+    uint32_t maxSymbol = 255;
+
+    U32 count[256];
+    size_t const mostFrequent = HIST_count(count, &maxSymbol, src, size);
+    FUZZ_ZASSERT(mostFrequent);
+    if (mostFrequent == size) {
+        /* RLE */
+        FUZZ_dataProducer_free(producer);
+        return 0;
+
+    }
+    FUZZ_ASSERT(maxSymbol <= 255);
+    tableLog = adjustTableLog(tableLog, maxSymbol);
+
+    size_t const wkspSize = HUF_WORKSPACE_SIZE;
+    void* wksp = FUZZ_malloc(wkspSize);
+    void* rBuf = FUZZ_malloc(size);
+    void* cBuf = FUZZ_malloc(cBufSize);
+    HUF_CElt* ct = (HUF_CElt*)FUZZ_malloc(HUF_CTABLE_SIZE(maxSymbol));
+    HUF_DTable* dt = (HUF_DTable*)FUZZ_malloc(HUF_DTABLE_SIZE(tableLog) * sizeof(HUF_DTable));
+    dt[0] = tableLog * 0x01000001;
+
+    tableLog = HUF_optimalTableLog(tableLog, size, maxSymbol, wksp, wkspSize, ct, count, flags);
+    FUZZ_ASSERT(tableLog <= 12);
+    tableLog = HUF_buildCTable_wksp(ct, count, maxSymbol, tableLog, wksp, wkspSize);
+    FUZZ_ZASSERT(tableLog);
+    size_t const tableSize = HUF_writeCTable_wksp(cBuf, cBufSize, ct, maxSymbol, tableLog, wksp, wkspSize);
+    if (ERR_isError(tableSize)) {
+        /* Errors on uncompressible data or cBufSize too small */
+        goto _out;
+    }
+    FUZZ_ZASSERT(tableSize);
+    if (symbols == 0) {
+        FUZZ_ZASSERT(HUF_readDTableX1_wksp(dt, cBuf, tableSize, wksp, wkspSize, flags));
+    } else {
+        size_t const ret = HUF_readDTableX2_wksp(dt, cBuf, tableSize, wksp, wkspSize, flags);
+        if (ERR_getErrorCode(ret) == ZSTD_error_tableLog_tooLarge) {
+            FUZZ_ZASSERT(HUF_readDTableX1_wksp(dt, cBuf, tableSize, wksp, wkspSize, flags));
+        } else {
+            FUZZ_ZASSERT(ret);
+        }
+    }
+
+    size_t cSize;
+    size_t rSize;
+    if (streams == 0) {
+        cSize = HUF_compress1X_usingCTable(cBuf, cBufSize, src, size, ct, flags);
+        FUZZ_ZASSERT(cSize);
+        if (cSize != 0)
+            rSize = HUF_decompress1X_usingDTable(rBuf, size, cBuf, cSize, dt, flags);
+    } else {
+        cSize = HUF_compress4X_usingCTable(cBuf, cBufSize, src, size, ct, flags);
+        FUZZ_ZASSERT(cSize);
+        if (cSize != 0)
+            rSize = HUF_decompress4X_usingDTable(rBuf, size, cBuf, cSize, dt, flags);
+    }
+    if (cSize != 0) {
+        FUZZ_ZASSERT(rSize);
+        FUZZ_ASSERT_MSG(rSize == size, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
+    }
+_out:
+    free(rBuf);
+    free(cBuf);
+    free(ct);
+    free(dt);
+    free(wksp);
+    FUZZ_dataProducer_free(producer);
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/raw_dictionary_round_trip.c

@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress) with
+ * a raw content dictionary, compares the result with the original, and calls
+ * abort() on corruption.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+#include "fuzz_third_party_seq_prod.h"
+
+static ZSTD_CCtx *cctx = NULL;
+static ZSTD_DCtx *dctx = NULL;
+
+static size_t roundTripTest(void *result, size_t resultCapacity,
+                            void *compressed, size_t compressedCapacity,
+                            const void *src, size_t srcSize,
+                            const void *dict, size_t dictSize,
+                            FUZZ_dataProducer_t *producer)
+{
+    ZSTD_dictContentType_e const dictContentType = ZSTD_dct_rawContent;
+    int const refPrefix = FUZZ_dataProducer_uint32Range(producer, 0, 1) != 0;
+    size_t cSize;
+
+    FUZZ_setRandomParameters(cctx, srcSize, producer);
+    /* Disable checksum so we can use sizes smaller than compress bound. */
+    FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 0));
+    if (refPrefix)
+        FUZZ_ZASSERT(ZSTD_CCtx_refPrefix_advanced(
+            cctx, dict, dictSize,
+            ZSTD_dct_rawContent));
+    else
+        FUZZ_ZASSERT(ZSTD_CCtx_loadDictionary_advanced(
+            cctx, dict, dictSize,
+            (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+            ZSTD_dct_rawContent));
+    cSize = ZSTD_compress2(cctx, compressed, compressedCapacity, src, srcSize);
+    FUZZ_ZASSERT(cSize);
+
+    if (refPrefix)
+        FUZZ_ZASSERT(ZSTD_DCtx_refPrefix_advanced(
+            dctx, dict, dictSize,
+            dictContentType));
+    else
+        FUZZ_ZASSERT(ZSTD_DCtx_loadDictionary_advanced(
+            dctx, dict, dictSize,
+            (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+            dictContentType));
+    {
+        size_t const ret = ZSTD_decompressDCtx(
+                dctx, result, resultCapacity, compressed, cSize);
+        return ret;
+    }
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_SEQ_PROD_SETUP();
+
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    uint8_t const* const srcBuf = src;
+    size_t const srcSize = FUZZ_dataProducer_uint32Range(producer, 0, size);
+    uint8_t const* const dictBuf = srcBuf + srcSize;
+    size_t const dictSize = size - srcSize;
+    size_t const decompSize = srcSize;
+    void* const decompBuf = FUZZ_malloc(decompSize);
+    size_t compSize = ZSTD_compressBound(srcSize);
+    void* compBuf;
+    /* Half of the time fuzz with a 1 byte smaller output size.
+     * This will still succeed because we force the checksum to be disabled,
+     * giving us 4 bytes of overhead.
+     */
+    compSize -= FUZZ_dataProducer_uint32Range(producer, 0, 1);
+    compBuf = FUZZ_malloc(compSize);
+
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    {
+        size_t const result =
+            roundTripTest(decompBuf, decompSize, compBuf, compSize, srcBuf, srcSize, dictBuf, dictSize, producer);
+        FUZZ_ZASSERT(result);
+        FUZZ_ASSERT_MSG(result == srcSize, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, decompBuf, srcSize), "Corruption!");
+    }
+    free(decompBuf);
+    free(compBuf);
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    FUZZ_SEQ_PROD_TEARDOWN();
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/regression_driver.c

@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#include "fuzz.h"
+#include "fuzz_helpers.h"
+#include "util.h"
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char const **argv) {
+  size_t const kMaxFileSize = (size_t)1 << 27;
+  int const kFollowLinks = 1;
+  FileNamesTable* files;
+  const char** const fnTable = argv + 1;
+  uint8_t *buffer = NULL;
+  size_t bufferSize = 0;
+  unsigned i;
+  unsigned numFilesTested = 0;
+  int ret = 0;
+
+  {
+    unsigned const numFiles = (unsigned)(argc - 1);
+#ifdef UTIL_HAS_CREATEFILELIST
+    files = UTIL_createExpandedFNT(fnTable, numFiles, kFollowLinks);
+#else
+    files = UTIL_createFNT_fromROTable(fnTable, numFiles);
+    assert(numFiles == files->tableSize);
+#endif
+  }
+  if (!files) {
+    fprintf(stderr, "ERROR: Failed to create file names table\n");
+    return 1;
+  }
+  if (files->tableSize == 0)
+    fprintf(stderr, "WARNING: No files passed to %s\n", argv[0]);
+  for (i = 0; i < files->tableSize; ++i) {
+    char const *fileName = files->fileNames[i];
+    size_t const fileSize = UTIL_getFileSize(fileName);
+    size_t readSize;
+    FILE *file;
+
+    DEBUGLOG(3, "Running %s", fileName);
+
+    /* Check that it is a regular file, and that the fileSize is valid.
+     * If it is not a regular file, then it may have been deleted since we
+     * constructed the list, so just skip it, but return an error exit code.
+     */
+    if (!UTIL_isRegularFile(fileName)) {
+      ret = 1;
+      continue;
+    }
+    FUZZ_ASSERT_MSG(fileSize <= kMaxFileSize, fileName);
+    /* Ensure we have a large enough buffer allocated */
+    if (fileSize > bufferSize) {
+      free(buffer);
+      buffer = (uint8_t *)malloc(fileSize);
+      FUZZ_ASSERT_MSG(buffer, fileName);
+      bufferSize = fileSize;
+    }
+    /* Open the file */
+    file = fopen(fileName, "rb");
+    FUZZ_ASSERT_MSG(file, fileName);
+    /* Read the file */
+    readSize = fread(buffer, 1, fileSize, file);
+    FUZZ_ASSERT_MSG(readSize == fileSize, fileName);
+    /* Close the file */
+    fclose(file);
+    /* Run the fuzz target */
+    LLVMFuzzerTestOneInput(buffer, fileSize);
+    ++numFilesTested;
+  }
+  fprintf(stderr, "Tested %u files: ", numFilesTested);
+  if (ret == 0) {
+    fprintf(stderr, "Success!\n");
+  } else {
+    fprintf(stderr, "Failure!\n");
+  }
+  free(buffer);
+  UTIL_freeFileNamesTable(files);
+  return ret;
+}

build_amd64/_deps/zstd-src/tests/fuzz/seekable_roundtrip.c

@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#include "zstd.h"
+#include "zstd_seekable.h"
+#include "fuzz_helpers.h"
+#include "fuzz_data_producer.h"
+
+static ZSTD_seekable *stream = NULL;
+static ZSTD_seekable_CStream *zscs = NULL;
+static const size_t kSeekableOverheadSize = ZSTD_seekTableFooterSize;
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+    size_t const compressedBufferSize = ZSTD_compressBound(size) + kSeekableOverheadSize;
+    uint8_t* compressedBuffer = (uint8_t*)malloc(compressedBufferSize);
+    uint8_t* decompressedBuffer = (uint8_t*)malloc(size);
+
+    int const cLevel = FUZZ_dataProducer_int32Range(producer, ZSTD_minCLevel(), ZSTD_maxCLevel());
+    unsigned const checksumFlag = FUZZ_dataProducer_int32Range(producer, 0, 1);
+    size_t const uncompressedSize = FUZZ_dataProducer_uint32Range(producer, 0, size);
+    size_t const offset = FUZZ_dataProducer_uint32Range(producer, 0, size - uncompressedSize);
+    size_t seekSize;
+
+    if (!zscs) {
+        zscs = ZSTD_seekable_createCStream();
+        FUZZ_ASSERT(zscs);
+    }
+    if (!stream) {
+        stream = ZSTD_seekable_create();
+        FUZZ_ASSERT(stream);
+    }
+
+    {   /* Perform a compression */
+        size_t const initStatus = ZSTD_seekable_initCStream(zscs, cLevel, checksumFlag, size);
+        size_t endStatus;
+        ZSTD_outBuffer out = { .dst=compressedBuffer, .pos=0, .size=compressedBufferSize };
+        ZSTD_inBuffer  in  = { .src=src, .pos=0, .size=size };
+        FUZZ_ASSERT(!ZSTD_isError(initStatus));
+
+        do {
+            size_t cSize = ZSTD_seekable_compressStream(zscs, &out, &in);
+            FUZZ_ASSERT(!ZSTD_isError(cSize));
+        } while (in.pos != in.size);
+
+        FUZZ_ASSERT(in.pos == in.size);
+        endStatus = ZSTD_seekable_endStream(zscs, &out);
+        FUZZ_ASSERT(!ZSTD_isError(endStatus));
+        seekSize = out.pos;
+    }
+
+    {   /* Decompress at an offset */
+        size_t const initStatus = ZSTD_seekable_initBuff(stream, compressedBuffer, seekSize);
+        size_t decompressedBytesTotal = 0;
+        size_t dSize;
+
+        FUZZ_ZASSERT(initStatus);
+        do {
+            dSize = ZSTD_seekable_decompress(stream, decompressedBuffer, uncompressedSize, offset);
+            FUZZ_ASSERT(!ZSTD_isError(dSize));
+            decompressedBytesTotal += dSize;
+        } while (decompressedBytesTotal < uncompressedSize && dSize > 0);
+        FUZZ_ASSERT(decompressedBytesTotal == uncompressedSize);
+    }
+
+    FUZZ_ASSERT_MSG(!FUZZ_memcmp(src+offset, decompressedBuffer, uncompressedSize), "Corruption!");
+
+    free(decompressedBuffer);
+    free(compressedBuffer);
+    FUZZ_dataProducer_free(producer);
+
+#ifndef STATEFUL_FUZZING
+    ZSTD_seekable_free(stream); stream = NULL;
+    ZSTD_seekable_freeCStream(zscs); zscs = NULL;
+#endif
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/seq_prod_fuzz_example/README.md

@@ -0,0 +1,12 @@
+# Fuzzing a Custom Sequence Producer Plugin
+This directory contains example code for using a custom sequence producer in the zstd fuzzers.
+
+You can build and run the code in this directory using these commands:
+```
+$ make corpora
+$ make -C seq_prod_fuzz_example/
+$ python3 ./fuzz.py build all --enable-fuzzer --enable-asan --enable-ubsan --cc clang --cxx clang++ --custom-seq-prod=seq_prod_fuzz_example/example_seq_prod.o
+$ python3 ./fuzz.py libfuzzer simple_round_trip
+```
+
+See `../fuzz_third_party_seq_prod.h` and `../README.md` for more information on zstd fuzzing.

build_amd64/_deps/zstd-src/tests/fuzz/seq_prod_fuzz_example/example_seq_prod.c

@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) Yann Collet, Meta Platforms, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#include "fuzz_third_party_seq_prod.h"
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+_Thread_local size_t threadLocalState;
+
+size_t FUZZ_seqProdSetup(void) {
+    threadLocalState = 0;
+    return 0;
+}
+
+size_t FUZZ_seqProdTearDown(void) {
+    return 0;
+}
+
+void* FUZZ_createSeqProdState(void) {
+    return calloc(1, sizeof(size_t));
+}
+
+size_t FUZZ_freeSeqProdState(void* state) {
+    free(state);
+    return 0;
+}
+
+size_t FUZZ_thirdPartySeqProd(
+    void* sequenceProducerState,
+    ZSTD_Sequence* outSeqs, size_t outSeqsCapacity,
+    const void* src, size_t srcSize,
+    const void* dict, size_t dictSize,
+    int compressionLevel,
+    size_t windowSize
+) {
+    /* Try to catch unsafe use of the shared state */
+    size_t* const sharedStatePtr = (size_t*)sequenceProducerState;
+    assert(*sharedStatePtr == threadLocalState);
+    (*sharedStatePtr)++; threadLocalState++;
+
+    /* Check that fallback is enabled when FUZZ_THIRD_PARTY_SEQ_PROD is defined */
+    return ZSTD_SEQUENCE_PRODUCER_ERROR;
+}

build_amd64/_deps/zstd-src/tests/fuzz/sequence_compression_api.c

@@ -0,0 +1,452 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test by generating an arbitrary
+ * array of sequences, generating the associated source buffer, calling
+ * ZSTD_compressSequences(), and then decompresses and compares the result with
+ * the original generated source buffer.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+#include "zstd_errors.h"
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+#include "fuzz_third_party_seq_prod.h"
+
+static ZSTD_CCtx* cctx = NULL;
+static ZSTD_DCtx* dctx = NULL;
+static void* literalsBuffer = NULL;
+static void* generatedSrc = NULL;
+static ZSTD_Sequence* generatedSequences = NULL;
+
+static void* dictBuffer = NULL;
+static ZSTD_CDict* cdict = NULL;
+static ZSTD_DDict* ddict = NULL;
+
+#define ZSTD_FUZZ_GENERATED_SRC_MAXSIZE (1 << 20) /* Allow up to 1MB generated data */
+#define ZSTD_FUZZ_GENERATED_LITERALS_SIZE (1 << 20) /* Fixed size 1MB literals buffer */
+#define ZSTD_FUZZ_MATCHLENGTH_MAXSIZE (1 << 18) /* Allow up to 256KB matches */
+#define ZSTD_FUZZ_GENERATED_DICT_MAXSIZE (1 << ZSTD_WINDOWLOG_MAX_32) /* Allow up to 1 << ZSTD_WINDOWLOG_MAX_32 dictionary */
+#define ZSTD_FUZZ_MAX_NBSEQ (1 << 17) /* Maximum of 128K sequences */
+
+/* Deterministic random number generator */
+#define FUZZ_RDG_rotl32(x,r) ((x << r) | (x >> (32 - r)))
+static uint32_t FUZZ_RDG_rand(uint32_t* src)
+{
+    static const uint32_t prime1 = 2654435761U;
+    static const uint32_t prime2 = 2246822519U;
+    uint32_t rand32 = *src;
+    rand32 *= prime1;
+    rand32 ^= prime2;
+    rand32  = FUZZ_RDG_rotl32(rand32, 13);
+    *src = rand32;
+    return rand32 >> 5;
+}
+
+/* Make a pseudorandom string - this simple function exists to avoid
+ * taking a dependency on datagen.h to have RDG_genBuffer().
+ */
+static char* generatePseudoRandomString(char* str, size_t size, FUZZ_dataProducer_t* producer) {
+    const char charset[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJK1234567890!@#$^&*()_";
+    uint32_t seed = FUZZ_dataProducer_uint32(producer);
+    if (size) {
+        for (size_t n = 0; n < size; n++) {
+            int key = FUZZ_RDG_rand(&seed) % (int) (sizeof charset - 1);
+            str[n] = charset[key];
+        }
+    }
+    return str;
+}
+
+/* Returns size of source buffer */
+static size_t decodeSequences(void* dst, size_t nbSequences,
+                              size_t literalsSize,
+                              const void* dict, size_t dictSize,
+                              ZSTD_SequenceFormat_e mode)
+{
+    const uint8_t* litPtr = literalsBuffer;
+    const uint8_t* const litBegin = literalsBuffer;
+    const uint8_t* const litEnd = litBegin + literalsSize;
+    const uint8_t* dictPtr = dict;
+    uint8_t* op = dst;
+    const uint8_t* const oend = (uint8_t*)dst + ZSTD_FUZZ_GENERATED_SRC_MAXSIZE;
+    size_t generatedSrcBufferSize = 0;
+    size_t bytesWritten = 0;
+
+    for (size_t i = 0; i < nbSequences; ++i) {
+        /* block boundary */
+        if (generatedSequences[i].offset == 0)
+            FUZZ_ASSERT(generatedSequences[i].matchLength == 0);
+
+        if (litPtr + generatedSequences[i].litLength > litEnd) {
+            litPtr = litBegin;
+        }
+        memcpy(op, litPtr, generatedSequences[i].litLength);
+        bytesWritten += generatedSequences[i].litLength;
+        op += generatedSequences[i].litLength;
+        litPtr += generatedSequences[i].litLength;
+
+        /* Copy over the match */
+        {   size_t matchLength = generatedSequences[i].matchLength;
+            size_t j = 0;
+            size_t k = 0;
+            if (dictSize != 0) {
+                if (generatedSequences[i].offset > bytesWritten) { /* Offset goes into the dictionary */
+                    size_t dictOffset = generatedSequences[i].offset - bytesWritten;
+                    size_t matchInDict = MIN(matchLength, dictOffset);
+                    for (; k < matchInDict; ++k) {
+                        op[k] = dictPtr[dictSize - dictOffset + k];
+                    }
+                    matchLength -= matchInDict;
+                    op += matchInDict;
+                }
+            }
+            for (; j < matchLength; ++j) {
+                op[j] = op[(ptrdiff_t)(j - generatedSequences[i].offset)];
+            }
+            op += j;
+            FUZZ_ASSERT(generatedSequences[i].matchLength == j + k);
+            bytesWritten += generatedSequences[i].matchLength;
+        }
+    }
+    generatedSrcBufferSize = bytesWritten;
+    FUZZ_ASSERT(litPtr <= litEnd);
+    if (mode == ZSTD_sf_noBlockDelimiters) {
+        const uint32_t lastLLSize = (uint32_t)(litEnd - litPtr);
+        if (lastLLSize <= (uint32_t)(oend - op)) {
+            memcpy(op, litPtr, lastLLSize);
+            generatedSrcBufferSize += lastLLSize;
+    }   }
+    return generatedSrcBufferSize;
+}
+
+/* Returns nb sequences generated
+ * Note : random sequences are always valid in ZSTD_sf_noBlockDelimiters mode.
+ * However, it can fail with ZSTD_sf_explicitBlockDelimiters,
+ * due to potential lack of space in
+ */
+static size_t generateRandomSequences(FUZZ_dataProducer_t* producer,
+                                      size_t literalsSizeLimit, size_t dictSize,
+                                      size_t windowLog, ZSTD_SequenceFormat_e mode)
+{
+    const uint32_t repCode = 0;  /* not used by sequence ingestion api */
+    size_t windowSize = 1ULL << windowLog;
+    size_t blockSizeMax = MIN(ZSTD_BLOCKSIZE_MAX, windowSize);
+    uint32_t matchLengthMax = ZSTD_FUZZ_MATCHLENGTH_MAXSIZE;
+    uint32_t bytesGenerated = 0;
+    uint32_t nbSeqGenerated = 0;
+    uint32_t isFirstSequence = 1;
+    uint32_t blockSize = 0;
+
+    if (mode == ZSTD_sf_explicitBlockDelimiters) {
+        /* ensure that no sequence can be larger than one block */
+        literalsSizeLimit = MIN(literalsSizeLimit, blockSizeMax/2);
+        matchLengthMax = MIN(matchLengthMax, (uint32_t)blockSizeMax/2);
+    }
+
+    while ( nbSeqGenerated < ZSTD_FUZZ_MAX_NBSEQ - 3 /* extra room for explicit delimiters */
+         && bytesGenerated < ZSTD_FUZZ_GENERATED_SRC_MAXSIZE
+         && !FUZZ_dataProducer_empty(producer)) {
+        uint32_t matchLength;
+        uint32_t matchBound = matchLengthMax;
+        uint32_t offset;
+        uint32_t offsetBound;
+        const uint32_t minLitLength = (isFirstSequence && (dictSize == 0));
+        const uint32_t litLength = FUZZ_dataProducer_uint32Range(producer, minLitLength, (uint32_t)literalsSizeLimit);
+        bytesGenerated += litLength;
+        if (bytesGenerated > ZSTD_FUZZ_GENERATED_SRC_MAXSIZE) {
+            break;
+        }
+        offsetBound = (bytesGenerated > windowSize) ? (uint32_t)windowSize : bytesGenerated + (uint32_t)dictSize;
+        offset = FUZZ_dataProducer_uint32Range(producer, 1, offsetBound);
+        if (dictSize > 0 && bytesGenerated <= windowSize) {
+            /* Prevent match length from being such that it would be associated with an offset too large
+             * from the decoder's perspective. If not possible (match would be too small),
+             * then reduce the offset if necessary.
+             */
+            const size_t bytesToReachWindowSize = windowSize - bytesGenerated;
+            if (bytesToReachWindowSize < ZSTD_MINMATCH_MIN) {
+                const uint32_t newOffsetBound = offsetBound > windowSize ? (uint32_t)windowSize : offsetBound;
+                offset = FUZZ_dataProducer_uint32Range(producer, 1, newOffsetBound);
+            } else {
+                matchBound = MIN(matchLengthMax, (uint32_t)bytesToReachWindowSize);
+            }
+        }
+        matchLength = FUZZ_dataProducer_uint32Range(producer, ZSTD_MINMATCH_MIN, matchBound);
+        bytesGenerated += matchLength;
+        if (bytesGenerated > ZSTD_FUZZ_GENERATED_SRC_MAXSIZE) {
+            break;
+        }
+        {   ZSTD_Sequence seq = {offset, litLength, matchLength, repCode};
+            const uint32_t lastLits = FUZZ_dataProducer_uint32Range(producer, 0, litLength);
+            #define SPLITPROB 6000
+            #define SPLITMARK 5234
+            const int split = (FUZZ_dataProducer_uint32Range(producer, 0, SPLITPROB) == SPLITMARK);
+            if (mode == ZSTD_sf_explicitBlockDelimiters) {
+                const size_t seqSize = seq.litLength + seq.matchLength;
+                if (blockSize + seqSize > blockSizeMax) {  /* reaching limit : must end block now */
+                    const ZSTD_Sequence endBlock = {0, 0, 0, 0};
+                    generatedSequences[nbSeqGenerated++] = endBlock;
+                    blockSize = (uint32_t)seqSize;
+                }
+                if (split) {
+                    const ZSTD_Sequence endBlock = {0, lastLits, 0, 0};
+                    generatedSequences[nbSeqGenerated++] = endBlock;
+                    assert(lastLits <= seq.litLength);
+                    seq.litLength -= lastLits;
+                    blockSize = (uint32_t)(seqSize - lastLits);
+                } else {
+                    blockSize += seqSize;
+                }
+            }
+            generatedSequences[nbSeqGenerated++] = seq;
+            isFirstSequence = 0;
+        }
+    }
+
+    if (mode == ZSTD_sf_explicitBlockDelimiters) {
+        /* always end sequences with a block delimiter */
+        const ZSTD_Sequence endBlock = {0, 0, 0, 0};
+        assert(nbSeqGenerated < ZSTD_FUZZ_MAX_NBSEQ);
+        generatedSequences[nbSeqGenerated++] = endBlock;
+    }
+    return nbSeqGenerated;
+}
+
+static size_t
+transferLiterals(void* dst, size_t dstCapacity, const ZSTD_Sequence* seqs, size_t nbSeqs, const void* src, size_t srcSize)
+{
+    size_t n;
+    char* op = dst;
+    char* const oend = op + dstCapacity;
+    const char* ip = src;
+    const char* const iend = ip + srcSize;
+    for (n=0; n<nbSeqs; n++) {
+        size_t litLen = seqs[n].litLength;
+        size_t mlen = seqs[n].matchLength;
+        assert(op + litLen < oend); (void)oend;
+        assert(ip + litLen + mlen <= iend); (void)iend;
+        memcpy(op, ip, litLen);
+        op += litLen;
+        ip += litLen + mlen;
+    }
+    assert(oend - op >= 8);
+    return (size_t)(op - (char*)dst);
+}
+
+static size_t roundTripTest_compressSequencesAndLiterals(
+                    void* result, size_t resultCapacity,
+                    void* compressed, size_t compressedCapacity,
+                    const void* src, size_t srcSize,
+                    const ZSTD_Sequence* seqs, size_t nbSeqs)
+{
+    size_t const litCapacity = srcSize + 8;
+    void* literals = malloc(litCapacity);
+    size_t cSize, litSize;
+
+    assert(literals);
+    litSize = transferLiterals(literals, litCapacity, seqs, nbSeqs, src, srcSize);
+
+    cSize = ZSTD_compressSequencesAndLiterals(cctx,
+                                compressed, compressedCapacity,
+                                   seqs, nbSeqs,
+                                   literals, litSize, litCapacity, srcSize);
+    free(literals);
+    if (ZSTD_getErrorCode(cSize) == ZSTD_error_cannotProduce_uncompressedBlock) {
+        /* Valid scenario : ZSTD_compressSequencesAndLiterals cannot generate uncompressed blocks */
+        return 0;
+    }
+    if (ZSTD_getErrorCode(cSize) == ZSTD_error_dstSize_tooSmall) {
+        /* Valid scenario : in explicit delimiter mode,
+         * it might be possible for the compressed size to outgrow dstCapacity.
+         * In which case, it's still a valid fuzzer scenario,
+         * but no roundtrip shall be possible */
+        return 0;
+    }
+
+    /* round-trip */
+    FUZZ_ZASSERT(cSize);
+    {   size_t const dSize = ZSTD_decompressDCtx(dctx, result, resultCapacity, compressed, cSize);
+        FUZZ_ZASSERT(dSize);
+        FUZZ_ASSERT_MSG(dSize == srcSize, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, result, srcSize), "Corruption!");
+        return dSize;
+    }
+}
+
+static size_t roundTripTest(void* result, size_t resultCapacity,
+                            void* compressed, size_t compressedCapacity,
+                            const void* src, size_t srcSize,
+                            const ZSTD_Sequence* seqs, size_t nbSeqs,
+                            unsigned hasDict,
+                            ZSTD_SequenceFormat_e mode)
+{
+    size_t cSize;
+    size_t dSize;
+
+    if (hasDict) {
+        FUZZ_ZASSERT(ZSTD_CCtx_refCDict(cctx, cdict));
+        FUZZ_ZASSERT(ZSTD_DCtx_refDDict(dctx, ddict));
+    }
+
+    {   int blockMode, validation;
+        /* compressSequencesAndLiterals() only supports explicitBlockDelimiters and no validation */
+        FUZZ_ZASSERT(ZSTD_CCtx_getParameter(cctx, ZSTD_c_blockDelimiters, &blockMode));
+        FUZZ_ZASSERT(ZSTD_CCtx_getParameter(cctx, ZSTD_c_validateSequences, &validation));
+        if ((blockMode == ZSTD_sf_explicitBlockDelimiters) && (!validation)) {
+            FUZZ_ZASSERT(roundTripTest_compressSequencesAndLiterals(result, resultCapacity, compressed, compressedCapacity, src, srcSize, seqs, nbSeqs));
+        }
+    }
+
+    cSize = ZSTD_compressSequences(cctx, compressed, compressedCapacity,
+                                   seqs, nbSeqs,
+                                   src, srcSize);
+    if ( (ZSTD_getErrorCode(cSize) == ZSTD_error_dstSize_tooSmall)
+      && (mode == ZSTD_sf_explicitBlockDelimiters) ) {
+        /* Valid scenario : in explicit delimiter mode,
+         * it might be possible for the compressed size to outgrow dstCapacity.
+         * In which case, it's still a valid fuzzer scenario,
+         * but no roundtrip shall be possible */
+        return 0;
+    }
+    /* round-trip */
+    FUZZ_ZASSERT(cSize);
+    dSize = ZSTD_decompressDCtx(dctx, result, resultCapacity, compressed, cSize);
+    FUZZ_ZASSERT(dSize);
+    FUZZ_ASSERT_MSG(dSize == srcSize, "Incorrect regenerated size");
+    FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, result, srcSize), "Corruption!");
+    return dSize;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t* src, size_t size)
+{
+    FUZZ_SEQ_PROD_SETUP();
+
+    void* rBuf;
+    size_t rBufSize;
+    void* cBuf;
+    size_t cBufSize;
+    size_t generatedSrcSize;
+    size_t nbSequences;
+    size_t dictSize = 0;
+    unsigned hasDict;
+    unsigned wLog;
+    int cLevel;
+    ZSTD_SequenceFormat_e mode;
+
+    FUZZ_dataProducer_t* const producer = FUZZ_dataProducer_create(src, size);
+    FUZZ_ASSERT(producer);
+
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    /* Generate window log first so we don't generate offsets too large */
+    wLog = FUZZ_dataProducer_uint32Range(producer, ZSTD_WINDOWLOG_MIN, ZSTD_WINDOWLOG_MAX);
+    cLevel = FUZZ_dataProducer_int32Range(producer, -3, 22);
+    mode = (ZSTD_SequenceFormat_e)FUZZ_dataProducer_int32Range(producer, 0, 1);
+
+    ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
+    ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, 0);
+    ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, cLevel);
+    ZSTD_CCtx_setParameter(cctx, ZSTD_c_windowLog, (int)wLog);
+    ZSTD_CCtx_setParameter(cctx, ZSTD_c_minMatch, ZSTD_MINMATCH_MIN);
+    ZSTD_CCtx_setParameter(cctx, ZSTD_c_validateSequences, 1);
+    ZSTD_CCtx_setParameter(cctx, ZSTD_c_blockDelimiters, (int)mode);
+    ZSTD_CCtx_setParameter(cctx, ZSTD_c_forceAttachDict, ZSTD_dictForceAttach);
+
+    if (!literalsBuffer) {
+        literalsBuffer = FUZZ_malloc(ZSTD_FUZZ_GENERATED_LITERALS_SIZE);
+        FUZZ_ASSERT(literalsBuffer);
+        literalsBuffer = generatePseudoRandomString(literalsBuffer, ZSTD_FUZZ_GENERATED_LITERALS_SIZE, producer);
+    }
+
+    if (!dictBuffer) { /* Generate global dictionary buffer */
+        ZSTD_compressionParameters cParams;
+
+        /* Generate a large dictionary buffer */
+        dictBuffer = calloc(ZSTD_FUZZ_GENERATED_DICT_MAXSIZE, 1);
+        FUZZ_ASSERT(dictBuffer);
+
+        /* Create global cdict and ddict */
+        cParams = ZSTD_getCParams(1, ZSTD_FUZZ_GENERATED_SRC_MAXSIZE, ZSTD_FUZZ_GENERATED_DICT_MAXSIZE);
+        cParams.minMatch = ZSTD_MINMATCH_MIN;
+        cParams.hashLog = ZSTD_HASHLOG_MIN;
+        cParams.chainLog = ZSTD_CHAINLOG_MIN;
+
+        cdict = ZSTD_createCDict_advanced(dictBuffer, ZSTD_FUZZ_GENERATED_DICT_MAXSIZE, ZSTD_dlm_byRef, ZSTD_dct_rawContent, cParams, ZSTD_defaultCMem);
+        ddict = ZSTD_createDDict_advanced(dictBuffer, ZSTD_FUZZ_GENERATED_DICT_MAXSIZE, ZSTD_dlm_byRef, ZSTD_dct_rawContent, ZSTD_defaultCMem);
+        FUZZ_ASSERT(cdict);
+        FUZZ_ASSERT(ddict);
+    }
+
+    FUZZ_ASSERT(cdict);
+    FUZZ_ASSERT(ddict);
+
+    hasDict = FUZZ_dataProducer_uint32Range(producer, 0, 1);
+    if (hasDict) {
+        dictSize = ZSTD_FUZZ_GENERATED_DICT_MAXSIZE;
+    }
+
+    if (!generatedSequences) {
+        generatedSequences = FUZZ_malloc(sizeof(ZSTD_Sequence)*ZSTD_FUZZ_MAX_NBSEQ);
+    }
+    if (!generatedSrc) {
+        generatedSrc = FUZZ_malloc(ZSTD_FUZZ_GENERATED_SRC_MAXSIZE);
+    }
+
+    nbSequences = generateRandomSequences(producer, ZSTD_FUZZ_GENERATED_LITERALS_SIZE, dictSize, wLog, mode);
+    generatedSrcSize = decodeSequences(generatedSrc, nbSequences, ZSTD_FUZZ_GENERATED_LITERALS_SIZE, dictBuffer, dictSize, mode);
+
+    /* Note : in explicit block delimiters mode,
+     * the fuzzer might generate a lot of small blocks.
+     * In which case, the final compressed size might be > ZSTD_compressBound().
+     * This is still a valid scenario fuzzer though, which makes it possible to check under-sized dstCapacity.
+     * The test just doesn't roundtrip. */
+    cBufSize = ZSTD_compressBound(generatedSrcSize);
+    cBuf = FUZZ_malloc(cBufSize);
+
+    rBufSize = generatedSrcSize;
+    rBuf = FUZZ_malloc(rBufSize);
+
+    {   const size_t result = roundTripTest(rBuf, rBufSize,
+                                        cBuf, cBufSize,
+                                        generatedSrc, generatedSrcSize,
+                                        generatedSequences, nbSequences,
+                                        hasDict, mode);
+        FUZZ_ASSERT(result <= generatedSrcSize);  /* can be 0 when no round-trip */
+    }
+
+    free(rBuf);
+    free(cBuf);
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+    free(generatedSequences); generatedSequences = NULL;
+    free(generatedSrc); generatedSrc = NULL;
+    free(literalsBuffer); literalsBuffer = NULL;
+#endif
+    FUZZ_SEQ_PROD_TEARDOWN();
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/simple_compress.c

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target attempts to compress the fuzzed data with the simple
+ * compression function with an output buffer that may be too small to
+ * ensure that the compressor never crashes.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "fuzz_helpers.h"
+#include "zstd.h"
+#include "zstd_errors.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+#include "fuzz_third_party_seq_prod.h"
+
+static ZSTD_CCtx *cctx = NULL;
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_SEQ_PROD_SETUP();
+
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    size_t const maxSize = ZSTD_compressBound(size);
+    size_t const bufSize = FUZZ_dataProducer_uint32Range(producer, 0, maxSize);
+
+    int const cLevel = FUZZ_dataProducer_int32Range(producer, kMinClevel, kMaxClevel);
+
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+
+    void *rBuf = FUZZ_malloc(bufSize);
+    size_t const ret = ZSTD_compressCCtx(cctx, rBuf, bufSize, src, size, cLevel);
+    if (ZSTD_isError(ret)) {
+        FUZZ_ASSERT(ZSTD_getErrorCode(ret) == ZSTD_error_dstSize_tooSmall);
+    }
+    free(rBuf);
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+#endif
+    FUZZ_SEQ_PROD_TEARDOWN();
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/simple_decompress.c

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target attempts to decompress the fuzzed data with the simple
+ * decompression function to ensure the decompressor never crashes.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include "fuzz_helpers.h"
+#include "zstd.h"
+#include "fuzz_data_producer.h"
+
+static ZSTD_DCtx *dctx = NULL;
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    {
+        size_t const bufSize = FUZZ_dataProducer_uint32Range(producer, 0, 10 * size);
+        void *rBuf = FUZZ_malloc(bufSize);
+        size_t const dSize = ZSTD_decompressDCtx(dctx, rBuf, bufSize, src, size);
+        if (!ZSTD_isError(dSize)) {
+            /* If decompression was successful, the content size from the frame header(s) should be valid. */
+            unsigned long long const expectedSize = ZSTD_findDecompressedSize(src, size);
+            FUZZ_ASSERT(expectedSize != ZSTD_CONTENTSIZE_ERROR);
+            FUZZ_ASSERT(expectedSize == ZSTD_CONTENTSIZE_UNKNOWN || expectedSize == dSize);
+        }
+        free(rBuf);
+    }
+
+    FUZZ_dataProducer_free(producer);
+
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/simple_round_trip.c

@@ -0,0 +1,182 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress),
+ * compares the result with the original, and calls abort() on corruption.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+#include "fuzz_third_party_seq_prod.h"
+
+static ZSTD_CCtx *cctx = NULL;
+static ZSTD_DCtx *dctx = NULL;
+
+static size_t getDecompressionMargin(void const* compressed, size_t cSize, size_t srcSize, int hasSmallBlocks, int maxBlockSize)
+{
+    size_t margin = ZSTD_decompressionMargin(compressed, cSize);
+    if (!hasSmallBlocks) {
+        /* The macro should be correct in this case, but it may be smaller
+         * because of e.g. block splitting, so take the smaller of the two.
+         */
+        ZSTD_FrameHeader zfh;
+        size_t marginM;
+        FUZZ_ZASSERT(ZSTD_getFrameHeader(&zfh, compressed, cSize));
+        if (maxBlockSize == 0) {
+            maxBlockSize = zfh.blockSizeMax;
+        } else {
+            maxBlockSize = MIN(maxBlockSize, (int)zfh.blockSizeMax);
+        }
+        marginM = ZSTD_DECOMPRESSION_MARGIN(srcSize, maxBlockSize);
+        if (marginM < margin)
+            margin = marginM;
+    }
+    return margin;
+}
+
+static size_t roundTripTest(void *result, size_t resultCapacity,
+                            void *compressed, size_t compressedCapacity,
+                            const void *src, size_t srcSize,
+                            FUZZ_dataProducer_t *producer)
+{
+    size_t cSize;
+    size_t dSize;
+    int targetCBlockSize = 0;
+    int maxBlockSize = 0;
+    if (FUZZ_dataProducer_uint32Range(producer, 0, 1)) {
+        size_t const remainingBytes = FUZZ_dataProducer_remainingBytes(producer);
+        FUZZ_setRandomParameters(cctx, srcSize, producer);
+        cSize = ZSTD_compress2(cctx, compressed, compressedCapacity, src, srcSize);
+        FUZZ_ZASSERT(cSize);
+        FUZZ_ZASSERT(ZSTD_CCtx_getParameter(cctx, ZSTD_c_targetCBlockSize, &targetCBlockSize));
+        FUZZ_ZASSERT(ZSTD_CCtx_getParameter(cctx, ZSTD_c_maxBlockSize, &maxBlockSize));
+        // Compress a second time and check for determinism
+        {
+            size_t const cSize0 = cSize;
+            XXH64_hash_t const hash0 = XXH64(compressed, cSize, 0);
+            FUZZ_dataProducer_rollBack(producer, remainingBytes);
+            FUZZ_setRandomParameters(cctx, srcSize, producer);
+            cSize = ZSTD_compress2(cctx, compressed, compressedCapacity, src, srcSize);
+            FUZZ_ASSERT(cSize == cSize0);
+            FUZZ_ASSERT(XXH64(compressed, cSize, 0) == hash0);
+        }
+    } else {
+        int const cLevel = FUZZ_dataProducer_int32Range(producer, kMinClevel, kMaxClevel);
+        cSize = ZSTD_compressCCtx(
+            cctx, compressed, compressedCapacity, src, srcSize, cLevel);
+        FUZZ_ZASSERT(cSize);
+        // Compress a second time and check for determinism
+        {
+            size_t const cSize0 = cSize;
+            XXH64_hash_t const hash0 = XXH64(compressed, cSize, 0);
+            cSize = ZSTD_compressCCtx(
+                cctx, compressed, compressedCapacity, src, srcSize, cLevel);
+            FUZZ_ASSERT(cSize == cSize0);
+            FUZZ_ASSERT(XXH64(compressed, cSize, 0) == hash0);
+        }
+    }
+    if (FUZZ_dataProducer_uint32Range(producer, 0, 1)) {
+        FUZZ_ZASSERT(ZSTD_DCtx_setParameter(dctx, ZSTD_d_maxBlockSize, maxBlockSize));
+    }
+    dSize = ZSTD_decompressDCtx(dctx, result, resultCapacity, compressed, cSize);
+    FUZZ_ZASSERT(dSize);
+    FUZZ_ASSERT_MSG(dSize == srcSize, "Incorrect regenerated size");
+    FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, result, dSize), "Corruption!");
+
+    {
+        size_t margin = getDecompressionMargin(compressed, cSize, srcSize, targetCBlockSize, maxBlockSize);
+        size_t const outputSize = srcSize + margin;
+        char* const output = (char*)FUZZ_malloc(outputSize);
+        char* const input = output + outputSize - cSize;
+        FUZZ_ASSERT(outputSize >= cSize);
+        memcpy(input, compressed, cSize);
+
+        dSize = ZSTD_decompressDCtx(dctx, output, outputSize, input, cSize);
+        FUZZ_ZASSERT(dSize);
+        FUZZ_ASSERT_MSG(dSize == srcSize, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, output, srcSize), "Corruption!");
+
+        free(output);
+    }
+
+    /* When superblock is enabled make sure we don't expand the block more than expected.
+     * NOTE: This test is currently disabled because superblock mode can arbitrarily
+     * expand the block in the worst case. Once superblock mode has been improved we can
+     * re-enable this test.
+     */
+    if (0 && targetCBlockSize != 0) {
+        size_t normalCSize;
+        FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_targetCBlockSize, 0));
+        normalCSize = ZSTD_compress2(cctx, compressed, compressedCapacity, src, srcSize);
+        FUZZ_ZASSERT(normalCSize);
+        {
+            size_t const bytesPerBlock = 3 /* block header */
+                + 5 /* Literal header */
+                + 6 /* Huffman jump table */
+                + 3 /* number of sequences */
+                + 1 /* symbol compression modes */;
+            size_t const expectedExpansion = bytesPerBlock * (1 + (normalCSize / MAX(1, targetCBlockSize)));
+            size_t const allowedExpansion = (srcSize >> 3) + 5 * expectedExpansion + 10;
+            FUZZ_ASSERT(cSize <= normalCSize + allowedExpansion);
+        }
+    }
+    return dSize;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_SEQ_PROD_SETUP();
+
+    size_t const rBufSize = size;
+    void* rBuf = FUZZ_malloc(rBufSize);
+    size_t cBufSize = ZSTD_compressBound(size);
+    void* cBuf;
+
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    /* Half of the time fuzz with a 1 byte smaller output size.
+     * This will still succeed because we don't use a dictionary, so the dictID
+     * field is empty, giving us 4 bytes of overhead.
+     */
+    cBufSize -= FUZZ_dataProducer_uint32Range(producer, 0, 1);
+
+    cBuf = FUZZ_malloc(cBufSize);
+
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    roundTripTest(rBuf, rBufSize, cBuf, cBufSize, src, size, producer);
+    free(rBuf);
+    free(cBuf);
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    FUZZ_SEQ_PROD_TEARDOWN();
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/stream_decompress.c

@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target attempts to decompress the fuzzed data with the simple
+ * decompression function to ensure the decompressor never crashes.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "fuzz_helpers.h"
+#include "zstd.h"
+#include "fuzz_data_producer.h"
+
+static ZSTD_DStream *dstream = NULL;
+uint32_t seed;
+
+static ZSTD_outBuffer makeOutBuffer(FUZZ_dataProducer_t *producer, void* buf, size_t bufSize)
+{
+  ZSTD_outBuffer buffer = { buf, 0, 0 };
+
+  if (FUZZ_dataProducer_empty(producer)) {
+    buffer.size = bufSize;
+  } else {
+    buffer.size = (FUZZ_dataProducer_uint32Range(producer, 0, bufSize));
+  }
+  FUZZ_ASSERT(buffer.size <= bufSize);
+
+  if (buffer.size == 0) {
+    buffer.dst = NULL;
+  }
+
+  return buffer;
+}
+
+static ZSTD_inBuffer makeInBuffer(const uint8_t **src, size_t *size,
+                                  FUZZ_dataProducer_t *producer)
+{
+  ZSTD_inBuffer buffer = { *src, 0, 0 };
+
+  FUZZ_ASSERT(*size > 0);
+  if (FUZZ_dataProducer_empty(producer)) {
+    buffer.size = *size;
+  } else {
+    buffer.size = (FUZZ_dataProducer_uint32Range(producer, 0, *size));
+  }
+  FUZZ_ASSERT(buffer.size <= *size);
+  *src += buffer.size;
+  *size -= buffer.size;
+
+  if (buffer.size == 0) {
+    buffer.src = NULL;
+  }
+
+  return buffer;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    int stableOutBuffer;
+    ZSTD_outBuffer out;
+    void* buf;
+    size_t bufSize;
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+    bufSize = MAX(10 * size, ZSTD_BLOCKSIZE_MAX);
+
+    /* Allocate all buffers and contexts if not already allocated */
+    buf = FUZZ_malloc(bufSize);
+
+    if (!dstream) {
+        dstream = ZSTD_createDStream();
+        FUZZ_ASSERT(dstream);
+    } else {
+        FUZZ_ZASSERT(ZSTD_DCtx_reset(dstream, ZSTD_reset_session_only));
+    }
+
+    stableOutBuffer = FUZZ_dataProducer_uint32Range(producer, 0, 10) == 5;
+    if (stableOutBuffer) {
+      FUZZ_ZASSERT(ZSTD_DCtx_setParameter(dstream, ZSTD_d_stableOutBuffer, 1));
+      out.dst = buf;
+      out.size = bufSize;
+      out.pos = 0;
+    } else {
+      out = makeOutBuffer(producer, buf, bufSize);
+    }
+
+    while (size > 0) {
+        ZSTD_inBuffer in = makeInBuffer(&src, &size, producer);
+        do {
+            size_t const rc = ZSTD_decompressStream(dstream, &out, &in);
+            if (ZSTD_isError(rc)) goto error;
+            if (out.pos == out.size) {
+                if (stableOutBuffer) goto error;
+                out = makeOutBuffer(producer, buf, bufSize);
+            }
+        } while (in.pos != in.size);
+    }
+
+error:
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeDStream(dstream); dstream = NULL;
+#endif
+    FUZZ_dataProducer_free(producer);
+    free(buf);
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/stream_round_trip.c

@@ -0,0 +1,218 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress),
+ * compares the result with the original, and calls abort() on corruption.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+#include "fuzz_third_party_seq_prod.h"
+
+ZSTD_CCtx *cctx = NULL;
+static ZSTD_DCtx *dctx = NULL;
+static uint8_t* cBuf = NULL;
+static uint8_t* rBuf = NULL;
+static size_t bufSize = 0;
+
+static ZSTD_outBuffer makeOutBuffer(uint8_t *dst, size_t capacity,
+                                    FUZZ_dataProducer_t *producer)
+{
+    ZSTD_outBuffer buffer = { dst, 0, 0 };
+
+    FUZZ_ASSERT(capacity > 0);
+    buffer.size = (FUZZ_dataProducer_uint32Range(producer, 1, capacity));
+    FUZZ_ASSERT(buffer.size <= capacity);
+
+    return buffer;
+}
+
+static ZSTD_inBuffer makeInBuffer(const uint8_t **src, size_t *size,
+                                  FUZZ_dataProducer_t *producer)
+{
+    ZSTD_inBuffer buffer = { *src, 0, 0 };
+
+    FUZZ_ASSERT(*size > 0);
+    buffer.size = (FUZZ_dataProducer_uint32Range(producer, 1, *size));
+    FUZZ_ASSERT(buffer.size <= *size);
+    *src += buffer.size;
+    *size -= buffer.size;
+
+    return buffer;
+}
+
+static size_t compress(uint8_t *dst, size_t capacity,
+                       const uint8_t *src, size_t srcSize,
+                     FUZZ_dataProducer_t *producer)
+{
+    size_t dstSize = 0;
+    ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
+    FUZZ_setRandomParameters(cctx, srcSize, producer);
+    int maxBlockSize;
+    FUZZ_ZASSERT(ZSTD_CCtx_getParameter(cctx, ZSTD_c_maxBlockSize, &maxBlockSize));
+
+    while (srcSize > 0) {
+        ZSTD_inBuffer in = makeInBuffer(&src, &srcSize, producer);
+        /* Mode controls the action. If mode == -1 we pick a new mode */
+        int mode = -1;
+        while (in.pos < in.size || mode != -1) {
+            ZSTD_outBuffer out = makeOutBuffer(dst, capacity, producer);
+            /* Previous action finished, pick a new mode. */
+            if (mode == -1) mode = FUZZ_dataProducer_uint32Range(producer, 0, 9);
+            switch (mode) {
+                case 0: /* fall-through */
+                case 1: /* fall-through */
+                case 2: {
+                    size_t const ret =
+                        ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_flush);
+                    FUZZ_ZASSERT(ret);
+                    if (ret == 0)
+                        mode = -1;
+                    break;
+                }
+                case 3: {
+                    size_t ret =
+                        ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end);
+                    FUZZ_ZASSERT(ret);
+                    /* Reset the compressor when the frame is finished */
+                    if (ret == 0) {
+                        ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
+                        if (FUZZ_dataProducer_uint32Range(producer, 0, 7) == 0) {
+                            size_t const remaining = in.size - in.pos;
+                            FUZZ_setRandomParameters(cctx, remaining, producer);
+                            /* Always use the same maxBlockSize */
+                            FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_maxBlockSize, maxBlockSize));
+                        }
+                        mode = -1;
+                    }
+                    break;
+                }
+                case 4: {
+                    ZSTD_inBuffer nullIn = { NULL, 0, 0 };
+                    ZSTD_outBuffer nullOut = { NULL, 0, 0 };
+                    size_t const ret = ZSTD_compressStream2(cctx, &nullOut, &nullIn, ZSTD_e_continue);
+                    FUZZ_ZASSERT(ret);
+                }
+                /* fall-through */
+                default: {
+                    size_t const ret =
+                        ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_continue);
+                    FUZZ_ZASSERT(ret);
+                    mode = -1;
+                }
+            }
+            dst += out.pos;
+            dstSize += out.pos;
+            capacity -= out.pos;
+        }
+    }
+    for (;;) {
+        ZSTD_inBuffer in = {NULL, 0, 0};
+        ZSTD_outBuffer out = makeOutBuffer(dst, capacity, producer);
+        size_t const ret = ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end);
+        FUZZ_ZASSERT(ret);
+
+        dst += out.pos;
+        dstSize += out.pos;
+        capacity -= out.pos;
+        if (ret == 0)
+            break;
+    }
+    return dstSize;
+}
+
+static size_t decompress(void* dst, size_t dstCapacity, void const* src, size_t srcSize, FUZZ_dataProducer_t* producer)
+{
+    ZSTD_inBuffer in = {src, srcSize, 0};
+    ZSTD_outBuffer out = {dst, dstCapacity, 0};
+    int maxBlockSize;
+    FUZZ_ZASSERT(ZSTD_CCtx_getParameter(cctx, ZSTD_c_maxBlockSize, &maxBlockSize));
+    if (FUZZ_dataProducer_uint32Range(producer, 0, 1)) {
+        FUZZ_ZASSERT(ZSTD_DCtx_setParameter(dctx, ZSTD_d_maxBlockSize, maxBlockSize));
+    }
+    while (in.pos < in.size) {
+        size_t const ret = ZSTD_decompressStream(dctx, &out, &in);
+        FUZZ_ZASSERT(ret);
+        FUZZ_ASSERT(ret == 0);
+    }
+    return out.pos;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_SEQ_PROD_SETUP();
+    size_t neededBufSize;
+
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    neededBufSize = ZSTD_compressBound(size) * 15;
+
+    /* Allocate all buffers and contexts if not already allocated */
+    if (neededBufSize > bufSize) {
+        free(cBuf);
+        free(rBuf);
+        cBuf = (uint8_t*)FUZZ_malloc(neededBufSize);
+        rBuf = (uint8_t*)FUZZ_malloc(neededBufSize);
+        bufSize = neededBufSize;
+    }
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    {
+        size_t const cSize = compress(cBuf, neededBufSize, src, size, producer);
+        size_t const rSize = decompress(rBuf, neededBufSize, cBuf, cSize, producer);
+        FUZZ_ZASSERT(rSize);
+        FUZZ_ASSERT_MSG(rSize == size, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
+
+        /* Test in-place decompression (note the macro doesn't work in this case) */
+        {
+            size_t const margin = ZSTD_decompressionMargin(cBuf, cSize);
+            size_t const outputSize = size + margin;
+            char* const output = (char*)FUZZ_malloc(outputSize);
+            char* const input = output + outputSize - cSize;
+            size_t dSize;
+            FUZZ_ASSERT(outputSize >= cSize);
+            memcpy(input, cBuf, cSize);
+
+            dSize = ZSTD_decompressDCtx(dctx, output, outputSize, input, cSize);
+            FUZZ_ZASSERT(dSize);
+            FUZZ_ASSERT_MSG(dSize == size, "Incorrect regenerated size");
+            FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, output, size), "Corruption!");
+
+            free(output);
+        }
+    }
+
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    FUZZ_SEQ_PROD_TEARDOWN();
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/zstd_frame_info.c

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target fuzzes all of the helper functions that consume compressed
+ * input.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    ZSTD_FrameHeader zfh;
+    if (size == 0) {
+        src = NULL;
+   }
+    /* You can fuzz any helper functions here that are fast, and take zstd
+     * compressed data as input. E.g. don't expect the input to be a dictionary,
+     * so don't fuzz ZSTD_getDictID_fromDict().
+     */
+    ZSTD_getFrameContentSize(src, size);
+    ZSTD_getDecompressedSize(src, size);
+    ZSTD_findFrameCompressedSize(src, size);
+    ZSTD_getDictID_fromFrame(src, size);
+    ZSTD_findDecompressedSize(src, size);
+    ZSTD_decompressBound(src, size);
+    ZSTD_frameHeaderSize(src, size);
+    ZSTD_isFrame(src, size);
+    ZSTD_getFrameHeader(&zfh, src, size);
+    ZSTD_getFrameHeader_advanced(&zfh, src, size, ZSTD_f_zstd1);
+    return 0;
+}

build_amd64/_deps/zstd-src/tests/fuzz/zstd_helpers.c

@@ -0,0 +1,208 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+#define ZDICT_STATIC_LINKING_ONLY
+
+#include <string.h>
+
+#include "zstd_helpers.h"
+#include "fuzz_helpers.h"
+#include "zstd.h"
+#include "zdict.h"
+#include "sequence_producer.h"
+#include "fuzz_third_party_seq_prod.h"
+
+const int kMinClevel = -3;
+const int kMaxClevel = 19;
+
+void* FUZZ_seqProdState = NULL;
+
+static void set(ZSTD_CCtx *cctx, ZSTD_cParameter param, int value)
+{
+    FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, param, value));
+}
+
+static unsigned produceParamValue(unsigned min, unsigned max,
+                                  FUZZ_dataProducer_t *producer) {
+    return FUZZ_dataProducer_uint32Range(producer, min, max);
+}
+
+static void setRand(ZSTD_CCtx *cctx, ZSTD_cParameter param, unsigned min,
+                    unsigned max, FUZZ_dataProducer_t *producer) {
+    unsigned const value = produceParamValue(min, max, producer);
+    set(cctx, param, value);
+}
+
+ZSTD_compressionParameters FUZZ_randomCParams(size_t srcSize, FUZZ_dataProducer_t *producer)
+{
+    /* Select compression parameters */
+    ZSTD_compressionParameters cParams;
+    cParams.windowLog = FUZZ_dataProducer_uint32Range(producer, ZSTD_WINDOWLOG_MIN, 15);
+    cParams.hashLog = FUZZ_dataProducer_uint32Range(producer, ZSTD_HASHLOG_MIN, 15);
+    cParams.chainLog = FUZZ_dataProducer_uint32Range(producer, ZSTD_CHAINLOG_MIN, 16);
+    cParams.searchLog = FUZZ_dataProducer_uint32Range(producer, ZSTD_SEARCHLOG_MIN, 9);
+    cParams.minMatch = FUZZ_dataProducer_uint32Range(producer, ZSTD_MINMATCH_MIN,
+                                          ZSTD_MINMATCH_MAX);
+    cParams.targetLength = FUZZ_dataProducer_uint32Range(producer, 0, 512);
+    cParams.strategy = FUZZ_dataProducer_uint32Range(producer, ZSTD_STRATEGY_MIN, ZSTD_STRATEGY_MAX);
+    return ZSTD_adjustCParams(cParams, srcSize, 0);
+}
+
+ZSTD_frameParameters FUZZ_randomFParams(FUZZ_dataProducer_t *producer)
+{
+    /* Select frame parameters */
+    ZSTD_frameParameters fParams;
+    fParams.contentSizeFlag = FUZZ_dataProducer_uint32Range(producer, 0, 1);
+    fParams.checksumFlag = FUZZ_dataProducer_uint32Range(producer, 0, 1);
+    fParams.noDictIDFlag = FUZZ_dataProducer_uint32Range(producer, 0, 1);
+    return fParams;
+}
+
+ZSTD_parameters FUZZ_randomParams(size_t srcSize, FUZZ_dataProducer_t *producer)
+{
+    ZSTD_parameters params;
+    params.cParams = FUZZ_randomCParams(srcSize, producer);
+    params.fParams = FUZZ_randomFParams(producer);
+    return params;
+}
+
+static void setSequenceProducerParams(ZSTD_CCtx *cctx, FUZZ_dataProducer_t *producer) {
+#ifdef FUZZ_THIRD_PARTY_SEQ_PROD
+    ZSTD_registerSequenceProducer(
+        cctx,
+        FUZZ_seqProdState,
+        FUZZ_thirdPartySeqProd
+    );
+#else
+    ZSTD_registerSequenceProducer(
+        cctx,
+        NULL,
+        simpleSequenceProducer
+    );
+#endif
+
+#ifdef FUZZ_THIRD_PARTY_SEQ_PROD
+    FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_enableSeqProducerFallback, 1));
+#else
+    setRand(cctx, ZSTD_c_enableSeqProducerFallback, 0, 1, producer);
+#endif
+    FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, 0));
+    FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_enableLongDistanceMatching, ZSTD_ps_disable));
+}
+
+void FUZZ_setRandomParameters(ZSTD_CCtx *cctx, size_t srcSize, FUZZ_dataProducer_t *producer)
+{
+    ZSTD_compressionParameters cParams = FUZZ_randomCParams(srcSize, producer);
+    set(cctx, ZSTD_c_windowLog, cParams.windowLog);
+    set(cctx, ZSTD_c_hashLog, cParams.hashLog);
+    set(cctx, ZSTD_c_chainLog, cParams.chainLog);
+    set(cctx, ZSTD_c_searchLog, cParams.searchLog);
+    set(cctx, ZSTD_c_minMatch, cParams.minMatch);
+    set(cctx, ZSTD_c_targetLength, cParams.targetLength);
+    set(cctx, ZSTD_c_strategy, cParams.strategy);
+    /* Select frame parameters */
+    setRand(cctx, ZSTD_c_contentSizeFlag, 0, 1, producer);
+    setRand(cctx, ZSTD_c_checksumFlag, 0, 1, producer);
+    setRand(cctx, ZSTD_c_dictIDFlag, 0, 1, producer);
+    /* Select long distance matching parameters */
+    setRand(cctx, ZSTD_c_enableLongDistanceMatching, ZSTD_ps_auto, ZSTD_ps_disable, producer);
+    setRand(cctx, ZSTD_c_ldmHashLog, ZSTD_HASHLOG_MIN, 16, producer);
+    setRand(cctx, ZSTD_c_ldmMinMatch, ZSTD_LDM_MINMATCH_MIN,
+            ZSTD_LDM_MINMATCH_MAX, producer);
+    setRand(cctx, ZSTD_c_ldmBucketSizeLog, 0, ZSTD_LDM_BUCKETSIZELOG_MAX,
+            producer);
+    setRand(cctx, ZSTD_c_ldmHashRateLog, ZSTD_LDM_HASHRATELOG_MIN,
+            ZSTD_LDM_HASHRATELOG_MAX, producer);
+    /* Set misc parameters */
+#ifndef ZSTD_MULTITHREAD
+    // To reproduce with or without ZSTD_MULTITHREAD, we are going to use
+    // the same amount of entropy.
+    unsigned const nbWorkers_value = produceParamValue(0, 2, producer);
+    unsigned const rsyncable_value = produceParamValue(0, 1, producer);
+    (void)nbWorkers_value;
+    (void)rsyncable_value;
+    set(cctx, ZSTD_c_nbWorkers, 0);
+    set(cctx, ZSTD_c_rsyncable, 0);
+#else
+    setRand(cctx, ZSTD_c_nbWorkers, 0, 2, producer);
+    setRand(cctx, ZSTD_c_rsyncable, 0, 1, producer);
+#endif
+    setRand(cctx, ZSTD_c_useRowMatchFinder, 0, 2, producer);
+    setRand(cctx, ZSTD_c_enableDedicatedDictSearch, 0, 1, producer);
+    setRand(cctx, ZSTD_c_forceMaxWindow, 0, 1, producer);
+    setRand(cctx, ZSTD_c_literalCompressionMode, 0, 2, producer);
+    setRand(cctx, ZSTD_c_forceAttachDict, 0, 2, producer);
+    setRand(cctx, ZSTD_c_blockSplitterLevel, 0, ZSTD_BLOCKSPLITTER_LEVEL_MAX, producer);
+    setRand(cctx, ZSTD_c_splitAfterSequences, 0, 2, producer);
+    setRand(cctx, ZSTD_c_deterministicRefPrefix, 0, 1, producer);
+    setRand(cctx, ZSTD_c_prefetchCDictTables, 0, 2, producer);
+    setRand(cctx, ZSTD_c_maxBlockSize, ZSTD_BLOCKSIZE_MAX_MIN, ZSTD_BLOCKSIZE_MAX, producer);
+    setRand(cctx, ZSTD_c_validateSequences, 0, 1, producer);
+    setRand(cctx, ZSTD_c_repcodeResolution, 0, 2, producer);
+    if (FUZZ_dataProducer_uint32Range(producer, 0, 1) == 0) {
+      setRand(cctx, ZSTD_c_srcSizeHint, ZSTD_SRCSIZEHINT_MIN, 2 * srcSize, producer);
+    }
+    if (FUZZ_dataProducer_uint32Range(producer, 0, 1) == 0) {
+      setRand(cctx, ZSTD_c_targetCBlockSize, ZSTD_TARGETCBLOCKSIZE_MIN, ZSTD_TARGETCBLOCKSIZE_MAX, producer);
+    }
+
+#ifdef FUZZ_THIRD_PARTY_SEQ_PROD
+    setSequenceProducerParams(cctx, producer);
+#else
+    if (FUZZ_dataProducer_uint32Range(producer, 0, 10) == 1) {
+        setSequenceProducerParams(cctx, producer);
+    } else {
+        ZSTD_registerSequenceProducer(cctx, NULL, NULL);
+    }
+#endif
+}
+
+FUZZ_dict_t FUZZ_train(void const* src, size_t srcSize, FUZZ_dataProducer_t *producer)
+{
+    size_t const dictSize = MAX(srcSize / 8, 1024);
+    size_t const totalSampleSize = dictSize * 11;
+    FUZZ_dict_t dict = { FUZZ_malloc(dictSize), dictSize };
+    char* const samples = (char*)FUZZ_malloc(totalSampleSize);
+    unsigned nbSamples = 100;
+    size_t* const samplesSizes = (size_t*)FUZZ_malloc(sizeof(size_t) * nbSamples);
+    size_t pos = 0;
+    size_t sample = 0;
+    ZDICT_fastCover_params_t params;
+
+    for (sample = 0; sample < nbSamples; ++sample) {
+      size_t const remaining = totalSampleSize - pos;
+      size_t const offset = FUZZ_dataProducer_uint32Range(producer, 0, MAX(srcSize, 1) - 1);
+      size_t const limit = MIN(srcSize - offset, remaining);
+      size_t const toCopy = MIN(limit, remaining / (nbSamples - sample));
+      memcpy(samples + pos, (const char*)src + offset, toCopy);
+      pos += toCopy;
+      samplesSizes[sample] = toCopy;
+    }
+    memset(samples + pos, 0, totalSampleSize - pos);
+
+    memset(&params, 0, sizeof(params));
+    params.accel = 5;
+    params.k = 40;
+    params.d = 8;
+    params.f = 14;
+    params.zParams.compressionLevel = 1;
+    dict.size = ZDICT_trainFromBuffer_fastCover(dict.buff, dictSize,
+        samples, samplesSizes, nbSamples, params);
+    if (ZSTD_isError(dict.size)) {
+        free(dict.buff);
+        memset(&dict, 0, sizeof(dict));
+    }
+
+    free(samplesSizes);
+    free(samples);
+
+    return dict;
+}

build_amd64/_deps/zstd-src/tests/fuzz/zstd_helpers.h

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+/**
+ * Helper functions for fuzzing.
+ */
+
+#ifndef ZSTD_HELPERS_H
+#define ZSTD_HELPERS_H
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include "zstd.h"
+#include "zstd_errors.h"
+#include "fuzz_data_producer.h"
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern const int kMinClevel;
+extern const int kMaxClevel;
+
+void FUZZ_setRandomParameters(ZSTD_CCtx *cctx, size_t srcSize, FUZZ_dataProducer_t *producer);
+
+ZSTD_compressionParameters FUZZ_randomCParams(size_t srcSize, FUZZ_dataProducer_t *producer);
+ZSTD_frameParameters FUZZ_randomFParams(FUZZ_dataProducer_t *producer);
+ZSTD_parameters FUZZ_randomParams(size_t srcSize, FUZZ_dataProducer_t *producer);
+
+typedef struct {
+  void* buff;
+  size_t size;
+} FUZZ_dict_t;
+
+/* Quickly train a dictionary from a source for fuzzing.
+ * NOTE: Don't use this to train production dictionaries, it is only optimized
+ * for speed, and doesn't care about dictionary quality.
+ */
+FUZZ_dict_t FUZZ_train(void const* src, size_t srcSize, FUZZ_dataProducer_t *producer);
+
+#ifdef FUZZ_THIRD_PARTY_SEQ_PROD
+extern void* FUZZ_seqProdState;
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ZSTD_HELPERS_H */