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/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index b348d6c24d6..4bb8332ea7d 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -325,13 +325,6 @@ void DarwinClang::AddLinkRuntimeLibArgs(const ArgList &Args,
       Args.hasArg(options::OPT_fprofile_instr_generate) ||
       Args.hasArg(options::OPT_fcreate_profile) ||
       Args.hasArg(options::OPT_coverage)) {
-    // 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");
-    }
-
     // Select the appropriate runtime library for the target.
     if (isTargetIOSBased())
       AddLinkRuntimeLib(Args, CmdArgs, "libclang_rt.profile_ios.a");