[XRay][darwin] Initial XRay in Darwin Support

Summary:
This change implements the changes required in both clang and
compiler-rt to allow building XRay-instrumented binaries in Darwin. For
now we limit this to x86_64. We also start building the XRay runtime
library in compiler-rt for osx.

A caveat to this is that we don't have the tests set up and running
yet, which we'll do in a set of follow-on changes.

This patch uses the monorepo layout for the coordinated change across
multiple projects.

Reviewers: kubamracek

Subscribers: mgorny, cfe-commits, llvm-commits

Differential Revision: https://reviews.llvm.org/D39114

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@317875 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/Driver/ToolChains/Darwin.cpp b/lib/Driver/ToolChains/Darwin.cpp
index 39c4525f84..e689d4fa44 100644
--- a/lib/Driver/ToolChains/Darwin.cpp
+++ b/lib/Driver/ToolChains/Darwin.cpp
@@ -18,6 +18,7 @@
 #include "clang/Driver/DriverDiagnostic.h"
 #include "clang/Driver/Options.h"
 #include "clang/Driver/SanitizerArgs.h"
+#include "clang/Driver/XRayArgs.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Option/ArgList.h"
 #include "llvm/Support/Path.h"
@@ -1098,6 +1099,11 @@ void DarwinClang::AddLinkRuntimeLibArgs(const ArgList &Args,
   if (Sanitize.needsEsanRt())
     AddLinkSanitizerLibArgs(Args, CmdArgs, "esan");
 
+  const XRayArgs& XRay = getXRayArgs();
+  if (XRay.needsXRayRt() && isTargetMacOS()) {
+    AddLinkRuntimeLib(Args, CmdArgs, "libclang_rt.xray_osx.a", RLO_AlwaysLink);
+  }
+
   // Otherwise link libSystem, then the dynamic runtime library, and finally any
   // target specific static runtime library.
   CmdArgs.push_back("-lSystem");