[XRay][compiler-rt] Remove reliance on C++ ABI features

Summary:
This fixes http://llvm.org/PR32274.

This change adds a test to ensure that we're able to link XRay modes and
the runtime to binaries that don't need to depend on the C++ standard
library or a C++ ABI library. In particular, we ensure that this will work
with C programs compiled+linked with XRay.

To make the test pass, we need to change a few things in the XRay
runtime implementations to remove the reliance on C++ ABI features. In
particular, we change the thread-safe function-local-static
initialisation to use pthread_* instead of the C++ features that ensure
non-trivial thread-local/function-local-static initialisation.

Depends on D47696.

Reviewers: dblaikie, jfb, kpw, eizan

Reviewed By: kpw

Subscribers: echristo, eizan, kpw, mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D46998

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@334262 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 0 deletions

diff --git a/test/xray/TestCases/Posix/c-test.cc b/test/xray/TestCases/Posix/c-test.cc
new file mode 100644
index 000000000..f8f5775d1
--- /dev/null
+++ b/test/xray/TestCases/Posix/c-test.cc
@@ -0,0 +1,15 @@
+// RUN: %clang_xray -g -o %t %s
+// RUN: rm xray-log.c-test.* || true
+// RUN: XRAY_OPTIONS=patch_premain=true:verbosity=1:xray_mode=xray-basic %t \
+// RUN:     2>&1 | FileCheck %s
+// RUN: rm xray-log.c-test.* || true
+//
+// REQUIRES: x86_64-target-arch
+// REQUIRES: built-in-llvm-tree
+__attribute__((xray_always_instrument)) void always() {}
+
+int main() {
+  always();
+}
+
+// CHECK: =={{[0-9].*}}==XRay: Log file in '{{.*}}'