[libFuzzer] Add Fuzzer to the list of sanitizers which support coverage.

Without this change, additional coverage flags specified after
-fsanitize=fuzzer would get discarded.

https://reviews.llvm.org/D34794

llvm-svn: 306734

clang/lib/Driver/SanitizerArgs.cpp

@@ -32,7 +32,7 @@ enum : SanitizerMask {
   RequiresPIE = DataFlow,
   NeedsUnwindTables = Address | Thread | Memory | DataFlow,
   SupportsCoverage = Address | KernelAddress | Memory | Leak | Undefined |
-                     Integer | Nullability | DataFlow,
+                     Integer | Nullability | DataFlow | Fuzzer,
   RecoverableByDefault = Undefined | Integer | Nullability,
   Unrecoverable = Unreachable | Return,
   LegacyFsanitizeRecoverMask = Undefined | Integer,

clang/test/Driver/fuzzer.c

@@ -15,10 +15,14 @@
 //
 // CHECK-LIBCXX-DARWIN: -lc++
 
+
 // Check that we don't link in libFuzzer.a when producing a shared object.
 // RUN: %clang -fsanitize=fuzzer %s -shared -o %t.so -### 2>&1 | FileCheck --check-prefixes=CHECK-NOLIB-SO %s
 // CHECK-NOLIB-SO-NOT: libLLVMFuzzer.a
 
+// RUN: %clang -fsanitize=fuzzer -fsanitize-coverage=trace-pc %s -### 2>&1 | FileCheck --check-prefixes=CHECK-MSG %s
+// CHECK-MSG-NOT: argument unused during compilation
+
 int LLVMFuzzerTestOneInput(const char *Data, long Size) {
   return 0;
 }