Create undef reference to profile hook symbol
Create undef reference to profile hook symbol when
PGO instrumentation is turned on. This allows
LLVM to omit emission of hook variable use method
for every single module instrumented.
llvm-svn: 251385
diff --git a/clang/lib/Driver/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index e8a2d83..d0f4dac 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -25,6 +25,7 @@
#include "llvm/Option/ArgList.h"
#include "llvm/Option/OptTable.h"
#include "llvm/Option/Option.h"
+#include "llvm/ProfileData/InstrProf.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
@@ -3811,6 +3812,18 @@
return Res;
}
+void Linux::addProfileRTLibs(const llvm::opt::ArgList &Args,
+ llvm::opt::ArgStringList &CmdArgs) const {
+ if (!needsProfileRT(Args)) return;
+
+ // Add linker option -u__llvm_runtime_variable to cause runtime
+ // initialization module to be linked in.
+ if (!Args.hasArg(options::OPT_coverage))
+ CmdArgs.push_back(Args.MakeArgString(
+ Twine("-u", llvm::getInstrProfRuntimeHookVarName())));
+ ToolChain::addProfileRTLibs(Args, CmdArgs);
+}
+
/// DragonFly - DragonFly tool chain which can call as(1) and ld(1) directly.
DragonFly::DragonFly(const Driver &D, const llvm::Triple &Triple,