From: Hans Wennborg <hans@hanshq.net>
Date: Fri, 5 Feb 2016 22:15:03 +0000 (+0000)
Subject: Merging r259931:
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=2d49f0a0ae8366964a93e3b7b26e29679bee7160;p=clang

Merging r259931:
------------------------------------------------------------------------
r259931 | uweigand | 2016-02-05 13:34:28 -0800 (Fri, 05 Feb 2016) | 33 lines

[SystemZ] Define __GCC_HAVE_SYNC_COMPARE_AND_SWAP macros

Define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_[1248] macros on SystemZ.

This fixes a miscompile of GCC C++11 standard library headers
due to use of those macros in an ABI-changing manner.

See e.g. /usr/include/c++/4.8.5/ext/concurrence.h:

  // Compile time constant that indicates prefered locking policy in
  // the current configuration.
  static const _Lock_policy __default_lock_policy =
#ifdef __GTHREADS
#if (defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2) \
     && defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4))
  _S_atomic;
#else
  _S_mutex;
#endif
#else
  _S_single;
#endif

A different choice of __default_lock_policy causes different
sizes of several of the C++11 data structures, which are then
incompatible when inlined in clang-compiled code with what the
(GCC-compiled) external library expects.

This in turn leads to various crashes when using std::thread
in code compiled with clang, as see e.g. via the ThreadPool
unit tests.  See PR 26473 for an example.


------------------------------------------------------------------------


git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_38@259939 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index 1bc6c51b9b..4f0b124895 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -6151,6 +6151,12 @@ public:
     Builder.defineMacro("__s390x__");
     Builder.defineMacro("__zarch__");
     Builder.defineMacro("__LONG_DOUBLE_128__");
+
+    Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_1");
+    Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2");
+    Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4");
+    Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8");
+
     if (HasTransactionalExecution)
       Builder.defineMacro("__HTM__");
     if (Opts.ZVector)
diff --git a/test/Preprocessor/predefined-arch-macros.c b/test/Preprocessor/predefined-arch-macros.c
index 66a96e431f..ea98e7fb0f 100644
--- a/test/Preprocessor/predefined-arch-macros.c
+++ b/test/Preprocessor/predefined-arch-macros.c
@@ -1787,6 +1787,10 @@
 // RUN:     -target s390x-unknown-linux \
 // RUN:   | FileCheck %s -check-prefix=CHECK_SYSTEMZ_Z10
 //
+// CHECK_SYSTEMZ_Z10: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1
+// CHECK_SYSTEMZ_Z10: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2
+// CHECK_SYSTEMZ_Z10: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
+// CHECK_SYSTEMZ_Z10: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8
 // CHECK_SYSTEMZ_Z10: #define __LONG_DOUBLE_128__ 1
 // CHECK_SYSTEMZ_Z10: #define __s390__ 1
 // CHECK_SYSTEMZ_Z10: #define __s390x__ 1
@@ -1796,6 +1800,10 @@
 // RUN:     -target s390x-unknown-linux \
 // RUN:   | FileCheck %s -check-prefix=CHECK_SYSTEMZ_ZEC12
 //
+// CHECK_SYSTEMZ_ZEC12: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1
+// CHECK_SYSTEMZ_ZEC12: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2
+// CHECK_SYSTEMZ_ZEC12: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
+// CHECK_SYSTEMZ_ZEC12: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8
 // CHECK_SYSTEMZ_ZEC12: #define __HTM__ 1
 // CHECK_SYSTEMZ_ZEC12: #define __LONG_DOUBLE_128__ 1
 // CHECK_SYSTEMZ_ZEC12: #define __s390__ 1