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

5 files changed, 22 insertions, 10 deletions

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 1dafcebf05c..82e6fafa23a 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -535,6 +535,8 @@ def fsanitize_undefined_trap_on_error : Flag<["-"], "fsanitize-undefined-trap-on
                                         Group<f_clang_Group>, Flags<[CC1Option]>;
 def fno_sanitize_undefined_trap_on_error : Flag<["-"], "fno-sanitize-undefined-trap-on-error">,
                                            Group<f_clang_Group>;
+def fsanitize_link_cxx_runtime : Flag<["-"], "fsanitize-link-c++-runtime">,
+                                 Group<f_clang_Group>;
 def funsafe_math_optimizations : Flag<["-"], "funsafe-math-optimizations">,
   Group<f_Group>;
 def fno_unsafe_math_optimizations : Flag<["-"], "fno-unsafe-math-optimizations">,
diff --git a/clang/include/clang/Driver/SanitizerArgs.h b/clang/include/clang/Driver/SanitizerArgs.h
index c79c4714f4f..c25687c701b 100644
--- a/clang/include/clang/Driver/SanitizerArgs.h
+++ b/clang/include/clang/Driver/SanitizerArgs.h
@@ -52,9 +52,9 @@ class SanitizerArgs {
   bool AsanZeroBaseShadow;
   bool UbsanTrapOnError;
   bool AsanSharedRuntime;
+  bool LinkCXXRuntimes;
 
  public:
-  SanitizerArgs();
   /// Parses the sanitizer arguments from an argument list.
   SanitizerArgs(const ToolChain &TC, const llvm::opt::ArgList &Args);
 
@@ -77,6 +77,7 @@ class SanitizerArgs {
     return (Kind & HasZeroBaseShadow) || AsanZeroBaseShadow;
   }
   bool needsUnwindTables() const { return Kind & NeedsUnwindTables; }
+  bool linkCXXRuntimes() const { return LinkCXXRuntimes; }
   void addArgs(const llvm::opt::ArgList &Args,
                llvm::opt::ArgStringList &CmdArgs) const;
 
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())
diff --git a/clang/test/Driver/sanitizer-ld.c b/clang/test/Driver/sanitizer-ld.c
index 786262c68b8..10f0b3060d8 100644
--- a/clang/test/Driver/sanitizer-ld.c
+++ b/clang/test/Driver/sanitizer-ld.c
@@ -195,6 +195,14 @@
 // CHECK-UBSAN-LINUX: "-lpthread"
 // CHECK-UBSAN-LINUX-NOT: "-lstdc++"
 
+// RUN: %clang -fsanitize=undefined -fsanitize-link-c++-runtime %s -### -o %t.o 2>&1 \
+// RUN:     -target i386-unknown-linux \
+// RUN:     --sysroot=%S/Inputs/basic_linux_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-UBSAN-LINUX-LINK-CXX %s
+// CHECK-UBSAN-LINUX-LINK-CXX-NOT: "-lstdc++"
+// CHECK-UBSAN-LINUX-LINK-CXX: "-whole-archive" "{{.*}}libclang_rt.ubsan_cxx-i386.a" "-no-whole-archive"
+// CHECK-UBSAN-LINUX-LINK-CXX-NOT: "-lstdc++"
+
 // RUN: %clangxx -fsanitize=undefined %s -### -o %t.o 2>&1 \
 // RUN:     -target i386-unknown-linux \
 // RUN:     -resource-dir=%S/Inputs/resource_dir \