doxygen: Skip libfuzzer header

libfuzzer contains preprocessor magic that makes doxygen choke.
Define `TESTING_LIBFUZZER_LIBFUZZER_EXPORTS_H_` so that doxygen skips over this header. We don't want to generate documentation for this non-tint code anyway.

Fixed: tint:1647
Change-Id: I084a6c3db0ffe492a62a1f9dcb0c30b68cebb9e0
Commit-Queue: Ben Clayton <>
Reviewed-by: Austin Eng <>
diff --git a/Doxyfile b/Doxyfile
index c28c268..cb5c120 100644
--- a/Doxyfile
+++ b/Doxyfile
@@ -2078,7 +2078,8 @@
 # recursively expanded use the := operator instead of the = operator.
 # This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
+PREDEFINED             = DOXYGEN \
+                         TESTING_LIBFUZZER_LIBFUZZER_EXPORTS_H_  # See:
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this
 # tag can be used to specify a list of macro names that should be expanded. The