Flag -fsanitize=fuzzer to enable libfuzzer

Previously, adding libfuzzer to a project was a multi-step procedure,
involving libfuzzer compilation, linking the library, and specifying
coverage flags.
With this change,libfuzzer can be enabled by adding a single
-fsanitize=fuzzer flag instead.

llvm-svn: 301212

1 files changed, 15 insertions, 0 deletions

diff --git a/clang/lib/Driver/ToolChains/Darwin.cpp b/clang/lib/Driver/ToolChains/Darwin.cpp
index ec2212f7a80..e41b50c40b2 100644
--- a/clang/lib/Driver/ToolChains/Darwin.cpp
+++ b/clang/lib/Driver/ToolChains/Darwin.cpp
@@ -930,6 +930,18 @@ void MachO::AddLinkRuntimeLib(const ArgList &Args, ArgStringList &CmdArgs,
   }
 }
 
+void MachO::AddFuzzerLinkArgs(const ArgList &Args, ArgStringList &CmdArgs) const {
+
+  // Go up one directory from Clang to find the libfuzzer archive file.
+  StringRef ParentDir = llvm::sys::path::parent_path(getDriver().InstalledDir);
+  SmallString<128> P(ParentDir);
+  llvm::sys::path::append(P, "lib", "libLLVMFuzzer.a");
+  CmdArgs.push_back(Args.MakeArgString(P));
+
+  // Libfuzzer is written in C++ and requires libcxx.
+  AddCXXStdlibLibArgs(Args, CmdArgs);
+}
+
 StringRef Darwin::getPlatformFamily() const {
   switch (TargetPlatform) {
     case DarwinPlatformKind::MacOS:
@@ -1041,6 +1053,8 @@ void DarwinClang::AddLinkRuntimeLibArgs(const ArgList &Args,
     AddLinkSanitizerLibArgs(Args, CmdArgs, "ubsan");
   if (Sanitize.needsTsanRt())
     AddLinkSanitizerLibArgs(Args, CmdArgs, "tsan");
+  if (Sanitize.needsFuzzer())
+    AddFuzzerLinkArgs(Args, CmdArgs);
   if (Sanitize.needsStatsRt()) {
     StringRef OS = isTargetMacOS() ? "osx" : "iossim";
     AddLinkRuntimeLib(Args, CmdArgs,
@@ -1895,6 +1909,7 @@ SanitizerMask Darwin::getSupportedSanitizers() const {
   SanitizerMask Res = ToolChain::getSupportedSanitizers();
   Res |= SanitizerKind::Address;
   Res |= SanitizerKind::Leak;
+  Res |= SanitizerKind::Fuzzer;
   if (isTargetMacOS()) {
     if (!isMacosxVersionLT(10, 9))
       Res |= SanitizerKind::Vptr;