Add documentation about potential fuzzing pitfall
Change-Id: I2ea01b3ad3359510bff3ffd298d4ed17d3677ffc
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/20146
Reviewed-by: David Neto <dneto@google.com>
Reviewed-by: dan sinclair <dsinclair@google.com>
diff --git a/README.md b/README.md
index 86a0b50..32f4620 100644
--- a/README.md
+++ b/README.md
@@ -16,6 +16,7 @@
* `TINT_BUILD_WGSL_READER` : enable the WGSL input reader (on by default)
* `TINT_BUILD_SPV_WRITER` : enable the SPIR-V output writer (on by default)
* `TINT_BUILD_WGSL_WRITER` : enable the WGSL output writer (on by default)
+ * `TINT_BUILD_FUZZERS` : enable building fuzzzers (off by default)
## Building
Tint uses Chromium dependency management so you need to install [depot_tools]
@@ -52,6 +53,20 @@
make # -j N for N-way parallel build
```
+### Fuzzers on MacOS
+If you are attempting fuzz, using `TINT_BUILD_FUZZERS=ON`, the version of llvm
+in the XCode SDK does not have the needed libfuzzer functionality included.
+
+The build error that you will see from using the XCode SDK will look something
+like this:
+```
+ld: file not found:/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/11.0.0/lib/darwin/libclang_rt.fuzzer_osx.a
+```
+
+The solution to this problem is to use a full version llvm, like what you would
+get via homebrew, `brew install llvm`, and use something like `CC=<path to full
+clang> cmake ..` to setup a build using that toolchain.
+
## Issues
Please file any issues or feature requests at
https://bugs.chromium.org/p/tint/issues/entry
