Use standard $CC as $HFUZZ_CC_ASAN to avoid expensive compiler search (#656)

infra/base-images/base-builder/compile_honggfuzz

@@ -20,12 +20,15 @@ echo -n "Compiling honggfuzz to $LIB_FUZZING_ENGINE ..."
 pushd $SRC/honggfuzz > /dev/null
 make clean
 CC=clang CFLAGS= make
-# libhfuzz.a willl be added by CC/CXX linker directly during linking,
-# but its defined here to satisfy the build infrastructure
+# libhfuzz.a will be added by CC/CXX linker directly during linking,
+# but it's defined here to satisfy the build infrastructure
 cp libhfuzz/libhfuzz.a $LIB_FUZZING_ENGINE
 cp honggfuzz $OUT/
 popd > /dev/null
 
+# Tell hfuzz-clang which exactly clang binary to use (otherwise hfuzz-clang
+# would try various ones (clang-5.0, clang-4.0, clang-devel, etc.)
+export HFUZZ_CC_PATH="$CC"
 # Relevant coverage flags are added by the compiler/linker
 export COVERAGE_FLAGS=
 export CC=$SRC/honggfuzz/hfuzz_cc/hfuzz-clang

infra/base-images/base-runner/run_fuzzer

@@ -54,7 +54,7 @@ elif [[ "$FUZZING_ENGINE" = honggfuzz ]]; then
   rm -rf /tmp/honggfuzz_workdir && mkdir /tmp/honggfuzz_workdir
   # --exit_upon_crash: exit whith a first crash seen
   # -R (report): save report file to this location
-  # -W (working dir): where the crashes and the report file go
+  # -W (working dir): where the crashes go
   # -v (verbose): don't use VTE UI, just stderr
   # -z: use software-instrumentation of clang (trace-pc-guard....)
   # -P: use persistent mode of fuzzing (i.e. LLVMFuzzerTestOneInput)