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libstdc++: Fix usage of __GXX_WEAK__ in TM TS support. 

* include/bits/c++config (_GLIBCXX_USE_WEAK_REF): New.
	(_GLIBCXX_TXN_SAFE, _GLIBCXX_TXN_SAFE_DYN): Use	_GLIBCXX_USE_WEAK_REF
	and move after its definition.
	* config/os/aix/os_defines.h (_GLIBCXX_USE_WEAK_REF): Override.
	* src/c++11/cow-stdexcept.cc: Use _GLIBCXX_USE_WEAK_REF instead of
	__GXX_WEAK__, and only provide transactional clones if
	_GLIBCXX_USE_WEAK_REF is true.  Don't provide stubs of libitm
	functions.

From-SVN: r232539
This commit is contained in:
Torvald Riegel 2016-01-18 20:09:55 +00:00 committed by Torvald Riegel
parent 66bc83c2a7
commit 9585381acd
4 changed files with 45 additions and 28 deletions
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11
libstdc++-v3/ChangeLog
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@ -1,3 +1,14 @@
2016-01-18 Torvald Riegel <triegel@redhat.com>
* include/bits/c++config (_GLIBCXX_USE_WEAK_REF): New.
(_GLIBCXX_TXN_SAFE, _GLIBCXX_TXN_SAFE_DYN): Use _GLIBCXX_USE_WEAK_REF
and move after its definition.
* config/os/aix/os_defines.h (_GLIBCXX_USE_WEAK_REF): Override.
* src/c++11/cow-stdexcept.cc: Use _GLIBCXX_USE_WEAK_REF instead of
__GXX_WEAK__, and only provide transactional clones if
_GLIBCXX_USE_WEAK_REF is true. Don't provide stubs of libitm
functions.
2016-01-18 Jonathan Wakely <jwakely@redhat.com>
PR libstdc++/60637

3
libstdc++-v3/config/os/aix/os_defines.h
View File

@ -48,4 +48,7 @@
#define __COMPATMATH__
#endif
// No support for referencing weak symbols without a definition.
#define _GLIBCXX_USE_WEAK_REF 0
#endif

36
libstdc++-v3/include/bits/c++config
View File

@ -483,20 +483,6 @@ namespace std
#define _GLIBCXX_USE_ALLOCATOR_NEW
// Conditionally enable annotations for the Transactional Memory TS on C++11.
// Most of the following conditions are due to limitations in the current
// implementation.
#if __cplusplus >= 201103L && _GLIBCXX_USE_CXX11_ABI \
&& _GLIBCXX_USE_DUAL_ABI && __cpp_transactional_memory >= 201505L \
&& !_GLIBCXX_FULLY_DYNAMIC_STRING && __GXX_WEAK__ \
&& _GLIBCXX_USE_ALLOCATOR_NEW
#define _GLIBCXX_TXN_SAFE transaction_safe
#define _GLIBCXX_TXN_SAFE_DYN transaction_safe_dynamic
#else
#define _GLIBCXX_TXN_SAFE
#define _GLIBCXX_TXN_SAFE_DYN
#endif
#else // !__cplusplus
# define _GLIBCXX_BEGIN_EXTERN_C
# define _GLIBCXX_END_EXTERN_C
@ -524,6 +510,28 @@ namespace std
# define _GLIBCXX_WEAK_DEFINITION
#endif
// By default, we assume that __GXX_WEAK__ also means that there is support
// for declaring functions as weak while not defining such functions. This
// allows for referring to functions provided by other libraries (e.g.,
// libitm) without depending on them if the respective features are not used.
#ifndef _GLIBCXX_USE_WEAK_REF
# define _GLIBCXX_USE_WEAK_REF __GXX_WEAK__
#endif
// Conditionally enable annotations for the Transactional Memory TS on C++11.
// Most of the following conditions are due to limitations in the current
// implementation.
#if __cplusplus >= 201103L && _GLIBCXX_USE_CXX11_ABI \
&& _GLIBCXX_USE_DUAL_ABI && __cpp_transactional_memory >= 201505L \
&& !_GLIBCXX_FULLY_DYNAMIC_STRING && _GLIBCXX_USE_WEAK_REF \
&& _GLIBCXX_USE_ALLOCATOR_NEW
#define _GLIBCXX_TXN_SAFE transaction_safe
#define _GLIBCXX_TXN_SAFE_DYN transaction_safe_dynamic
#else
#define _GLIBCXX_TXN_SAFE
#define _GLIBCXX_TXN_SAFE_DYN
#endif
// The remainder of the prewritten config is automatic; all the
// user hooks are listed above.

23
libstdc++-v3/src/c++11/cow-stdexcept.cc
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@ -179,6 +179,13 @@ _GLIBCXX_END_NAMESPACE_VERSION
// Furthermore, _Rep will always have been allocated or deallocated via
// global new or delete, so nontransactional writes we do to _Rep cannot
// interfere with transactional accesses.
// We depend on having support for referencing functions declared weak that
// are not defined by us. Without such support, the exceptions will not be
// declared transaction-safe, so we just don't provide transactional clones
// in this case.
#if _GLIBCXX_USE_WEAK_REF
extern "C" {
#ifndef _GLIBCXX_MANGLE_SIZE_T
@ -195,7 +202,6 @@ extern "C" {
# define ITM_REGPARM
#endif
#if __GXX_WEAK__
// Declare all libitm symbols we rely on, but make them weak so that we do
// not depend on libitm.
extern void* _ZGTtnaX (size_t sz) __attribute__((weak));
@ -213,19 +219,6 @@ extern void _ITM_memcpyRnWt(void *, const void *, size_t)
extern void _ITM_addUserCommitAction(void (*)(void *), uint64_t, void *)
ITM_REGPARM __attribute__((weak));
#else
// If there is no support for weak symbols, create dummies. The exceptions
// will not be declared transaction_safe in this case.
void* _ZGTtnaX (size_t) { return NULL; }
void _ZGTtdlPv (void*) { }
uint8_t _ITM_RU1(const uint8_t *) { return 0; }
uint32_t _ITM_RU4(const uint32_t *) { return 0; }
uint64_t _ITM_RU8(const uint64_t *) { return 0; }
void _ITM_memcpyRtWn(void *, const void *, size_t) { }
void _ITM_memcpyRnWt(void *, const void *, size_t) { }
void _ITM_addUserCommitAction(void (*)(void *), uint64_t, void *) { };
#endif
}
// A transactional version of basic_string::basic_string(const char *s)
@ -441,3 +434,5 @@ CTORDTOR(14overflow_error, std::overflow_error, runtime_error)
CTORDTOR(15underflow_error, std::underflow_error, runtime_error)
}
#endif // _GLIBCXX_USE_WEAK_REF