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Fuzz targets used by [oss-fuzz](https://github.com/google/oss-fuzz/).
## How to add new targets
Add **fuzz_target_name.c** and edit `meson.build` accordingly.
New targets are picked up by oss-fuzz automatically within a day. Targets must not be renamed once added.
Add (optional) **fuzz_target_name.dict** containing keywords and magic bytes.
Add (optional) **fuzz_target_name.corpus** with file names on separate lines. Wildcards `?`, `*` and `**` are supported. Examples below.
```bash
tests/* # all files in directory tests
tests/** # all files in directory tests and sub-directories
**.rq # all files ending with .rq in the repository
```
Recommended reading: [Fuzz Target](https://llvm.org/docs/LibFuzzer.html#fuzz-target), [Dictionaries](https://llvm.org/docs/LibFuzzer.html#dictionaries), [Corpus](https://llvm.org/docs/LibFuzzer.html#corpus)
## How to reproduce oss-fuzz bugs locally
Build with at least the following flags, choosing a sanitizer as needed. A somewhat recent version of [clang](http://clang.llvm.org/) is recommended.
```bash
$ CC=clang CXX=clang++ meson DIR -Db_sanitize=<address|undefined> -Db_lundef=false
```
Afterwards run the affected target against the provided test case.
```bash
$ DIR/fuzzing/fuzz_target_name FILE
```
#### FAQs
###### What about Memory Sanitizer (MSAN)?
Correct MSAN instrumentation is [difficult to achieve](https://clang.llvm.org/docs/MemorySanitizer.html#handling-external-code) locally, so false positives are very likely to mask the actual bug.
If need be, [you can still reproduce](https://google.github.io/oss-fuzz/advanced-topics/reproducing/#building-using-docker) those bugs with the oss-fuzz provided docker images.
###### There are no file/function names in the stack trace.
`llvm-symbolizer` must be in `PATH`.
###### UndefinedBehavior Sanitizer (UBSAN) doesn't provide a stack trace.
Set environment variable `UBSAN_OPTIONS` to `print_stacktrace=1` prior to running the target.
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