InstrProf: Emit runtime hook directly in IRGen

-u behaviour is apparently not portable between linkers (see cfe-commits
discussions for r204379 and r205012).  I've moved the logic to IRGen,
where it should have been in the first place.

I don't have a Linux system to test this on, so it's possible this logic
*still* doesn't pull in the instrumented profiling runtime on Linux.

I'm in the process of getting tests going on the compiler-rt side
(llvm-commits "[PATCH] InstrProf: Add initial compiler-rt test").  Once
we have tests for the full flow there, the runtime logic should get a
whole lot less brittle.

<rdar://problem/16458307>

llvm-svn: 205023

1 files changed, 0 insertions, 7 deletions

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 2141cc9656b..9a31eb9f9d6 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1817,13 +1817,6 @@ static void addProfileRT(
         Args.hasArg(options::OPT_coverage)))
     return;
 
-  // Pull in runtime for -fprofile-inst-generate.  This is required since there
-  // are no calls to the runtime in the code.
-  if (Args.hasArg(options::OPT_fprofile_instr_generate)) {
-    CmdArgs.push_back("-u");
-    CmdArgs.push_back("___llvm_profile_runtime");
-  }
-
   SmallString<128> LibProfile = getCompilerRTLibDir(TC);
   llvm::sys::path::append(LibProfile,
       Twine("libclang_rt.profile-") + getArchNameForCompilerRTLib(TC) + ".a");