Add -link-cxx-sanitizer driver flag.

Summary:
This flag can be used to force linking of CXX-specific parts
of sanitizer runtimes into the final executable. It gives more precise
control than --driver-mode=g++ and comes handy when user links several
object files with sanitized C++ code into an executable, but wants
to provide libstdc++ himself, instead of relying on Clang dirver's
behavior.

Test Plan: clang regression test suite

Reviewers: chandlerc, rsmith

Reviewed By: rsmith

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D4824

llvm-svn: 215252

2 files changed, 10 insertions, 9 deletions

diff --git a/clang/lib/Driver/SanitizerArgs.cpp b/clang/lib/Driver/SanitizerArgs.cpp
index b64f0275768..c192034236d 100644
--- a/clang/lib/Driver/SanitizerArgs.cpp
+++ b/clang/lib/Driver/SanitizerArgs.cpp
@@ -28,10 +28,7 @@ void SanitizerArgs::clear() {
   AsanZeroBaseShadow = false;
   UbsanTrapOnError = false;
   AsanSharedRuntime = false;
-}
-
-SanitizerArgs::SanitizerArgs() {
-  clear();
+  LinkCXXRuntimes = false;
 }
 
 SanitizerArgs::SanitizerArgs(const ToolChain &TC,
@@ -168,6 +165,10 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
     AsanZeroBaseShadow =
         (TC.getTriple().getEnvironment() == llvm::Triple::Android);
   }
+
+  // Parse -link-cxx-sanitizer flag.
+  LinkCXXRuntimes =
+      Args.hasArg(options::OPT_fsanitize_link_cxx_runtime) || D.CCCIsCXX();
 }
 
 void SanitizerArgs::addArgs(const llvm::opt::ArgList &Args,
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 860454a22b7..65760b49baa 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -2273,13 +2273,13 @@ static void addDfsanRT(const ToolChain &TC, const ArgList &Args,
 static void addSanitizerRuntimes(const ToolChain &TC, const ArgList &Args,
                                  ArgStringList &CmdArgs) {
   const SanitizerArgs &Sanitize = TC.getSanitizerArgs();
-  const Driver &D = TC.getDriver();
   if (Sanitize.needsUbsanRt())
-    addUbsanRT(TC, Args, CmdArgs, D.CCCIsCXX(),
-                    Sanitize.needsAsanRt() || Sanitize.needsTsanRt() ||
-                    Sanitize.needsMsanRt() || Sanitize.needsLsanRt());
+    addUbsanRT(TC, Args, CmdArgs, Sanitize.linkCXXRuntimes(),
+               Sanitize.needsAsanRt() || Sanitize.needsTsanRt() ||
+                   Sanitize.needsMsanRt() || Sanitize.needsLsanRt());
   if (Sanitize.needsAsanRt())
-    addAsanRT(TC, Args, CmdArgs, Sanitize.needsSharedAsanRt(), D.CCCIsCXX());
+    addAsanRT(TC, Args, CmdArgs, Sanitize.needsSharedAsanRt(),
+              Sanitize.linkCXXRuntimes());
   if (Sanitize.needsTsanRt())
     addTsanRT(TC, Args, CmdArgs);
   if (Sanitize.needsMsanRt())