[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

llvm-svn: 314188

diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp
index aa8276c..757ebda 100644 (file)
--- a/clang/lib/Driver/ToolChains/Gnu.cpp
+++ b/clang/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/clang/test/Driver/XRay/lit.local.cfg b/clang/test/Driver/XRay/lit.local.cfg
index 34040d2..56420cf 100644 (file)
--- a/clang/test/Driver/XRay/lit.local.cfg
+++ b/clang/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/clang/test/Driver/XRay/xray-shared-noxray.cpp b/clang/test/Driver/XRay/xray-shared-noxray.cpp
new file mode 100644 (file)
index 0000000..564df88
--- /dev/null
+++ b/clang/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