r259931 - [SystemZ] Define __GCC_HAVE_SYNC_COMPARE_AND_SWAP macros

[Ulrich Weigand via cfe-commits]

Author: uweigand
Date: Fri Feb  5 15:34:28 2016
New Revision: 259931

URL: http://llvm.org/viewvc/llvm-project?rev=259931&view=rev
Log:
[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.


Modified:
    cfe/trunk/lib/Basic/Targets.cpp
    cfe/trunk/test/Preprocessor/predefined-arch-macros.c

Modified: cfe/trunk/lib/Basic/Targets.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/Targets.cpp?rev=259931&r1=259930&r2=259931&view=diff
==============================================================================
--- cfe/trunk/lib/Basic/Targets.cpp (original)
+++ cfe/trunk/lib/Basic/Targets.cpp Fri Feb  5 15:34:28 2016
@@ -6166,6 +6166,12 @@ 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)

Modified: cfe/trunk/test/Preprocessor/predefined-arch-macros.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Preprocessor/predefined-arch-macros.c?rev=259931&r1=259930&r2=259931&view=diff
==============================================================================
--- cfe/trunk/test/Preprocessor/predefined-arch-macros.c (original)
+++ cfe/trunk/test/Preprocessor/predefined-arch-macros.c Fri Feb  5 15:34:28 2016
@@ -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