From 3d6b342fee947f19830af2267263e710d90c8a01 Mon Sep 17 00:00:00 2001
From: Dean Michael Berris <dberris@google.com>
Date: Tue, 26 Sep 2017 03:18:11 +0000
Subject: [PATCH] [XRay][Driver] Do not link in XRay runtime in shared libs

Summary:
This change ensures that we don't link in the XRay runtime when building
shared libraries with clang. This doesn't prevent us from building
shared libraris tht have XRay instrumentation sleds, but it does prevent
us from linking in the static XRay runtime into a shared library.

The XRay runtime currently doesn't support dynamic registration of
instrumentation sleds in shared objects, which we'll start enabling in
the future. That work has to happen in the back-end and in the runtime.

Reviewers: rnk, pelikan

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D38226

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@314188 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Driver/ToolChains/Gnu.cpp           |  5 +++++
 test/Driver/XRay/lit.local.cfg          | 19 +++++++++++++++++++
 test/Driver/XRay/xray-shared-noxray.cpp | 16 ++++++++++++++++
 3 files changed, 40 insertions(+)
 create mode 100644 test/Driver/XRay/xray-shared-noxray.cpp

diff --git a/lib/Driver/ToolChains/Gnu.cpp b/lib/Driver/ToolChains/Gnu.cpp
index aa8276c1fa..757ebda46d 100644
--- a/lib/Driver/ToolChains/Gnu.cpp
+++ b/lib/Driver/ToolChains/Gnu.cpp
@@ -206,6 +206,10 @@ void tools::gcc::Linker::RenderExtraToolArgs(const JobAction &JA,
 
 static bool addXRayRuntime(const ToolChain &TC, const ArgList &Args,
                            ArgStringList &CmdArgs) {
+  // Do not add the XRay runtime to shared libraries.
+  if (Args.hasArg(options::OPT_shared))
+    return false;
+
   if (Args.hasFlag(options::OPT_fxray_instrument,
                    options::OPT_fnoxray_instrument, false)) {
     CmdArgs.push_back("-whole-archive");
@@ -213,6 +217,7 @@ static bool addXRayRuntime(const ToolChain &TC, const ArgList &Args,
     CmdArgs.push_back("-no-whole-archive");
     return true;
   }
+
   return false;
 }
 
diff --git a/test/Driver/XRay/lit.local.cfg b/test/Driver/XRay/lit.local.cfg
index 34040d2261..56420cfecc 100644
--- a/test/Driver/XRay/lit.local.cfg
+++ b/test/Driver/XRay/lit.local.cfg
@@ -1,2 +1,21 @@
 target_triple_components = config.target_triple.split('-')
 config.available_features.update(target_triple_components)
+
+# Only run the tests in platforms where XRay instrumentation is supported.
+supported_targets = [
+    'amd64', 'x86_64', 'x86_64h', 'arm', 'aarch64', 'arm64', 'powerpc64le',
+    'mips', 'mipsel', 'mips64', 'mips64el'
+]
+
+# Only on platforms we support.
+supported_oses = [
+    'linux'
+]
+
+triple_set = set(target_triple_components)
+if len(triple_set.intersection(supported_targets)) == 0:
+  config.unsupported = True
+
+# Do not run for 'android' despite being linux.
+if len(triple_set.intersection(supported_oses)) == 0 or 'android' in triple_set:
+  config.unsupported = True
diff --git a/test/Driver/XRay/xray-shared-noxray.cpp b/test/Driver/XRay/xray-shared-noxray.cpp
new file mode 100644
index 0000000000..564df88c4e
--- /dev/null
+++ b/test/Driver/XRay/xray-shared-noxray.cpp
@@ -0,0 +1,16 @@
+// RUN: %clangxx -shared -fPIC -o /dev/null -v -fxray-instrument %s 2>&1 | \
+// RUN:     FileCheck %s --check-prefix=SHARED
+// RUN: %clangxx -static -o /dev/null -v -fxray-instrument %s 2>&1 -DMAIN | \
+// RUN:     FileCheck %s --check-prefix=STATIC
+// RUN: %clangxx -static -fPIE -o /dev/null -v -fxray-instrument %s 2>&1 \
+// RUN:     -DMAIN | FileCheck %s --check-prefix=STATIC
+//
+// SHARED-NOT: {{clang_rt\.xray-}}
+// STATIC: {{clang_rt\.xray-}}
+//
+// REQUIRES: linux
+int foo() { return 42; }
+
+#ifdef MAIN
+int main() { return foo(); }
+#endif
-- 
2.50.0