| Message ID | 20160116134140.GO15084@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 16/01/16 13:41 +0000, Jonathan Wakely wrote: >On 16/01/16 14:35 +0100, Jakub Jelinek wrote: >>On Sat, Jan 16, 2016 at 07:47:33AM -0500, David Edelsohn wrote: >>>stage1 libstdc++ builds just fine. the problem is stage2 configure >>>fails due to missing ITM_xxx symbols when configure tries to compile >>>and run conftest programs. >> >>On x86_64-linux, the _ITM_xxx symbols are undef weak ones and thus it is >>fine to load libstdc++ without libitm and libstdc++ doesn't depend on >>libitm. >> >>So, is AIX defining __GXX_WEAK__ or not? Perhaps some other macro or >>configure check needs to be used to determine if undefined weak symbols >>work the way libstdc++ needs them to. >> >>#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)); >>extern void _ZGTtdlPv (void* ptr) __attribute__((weak)); >>extern uint8_t _ITM_RU1(const uint8_t *p) >> ITM_REGPARM __attribute__((weak)); >>extern uint32_t _ITM_RU4(const uint32_t *p) >> ITM_REGPARM __attribute__((weak)); >>extern uint64_t _ITM_RU8(const uint64_t *p) >> ITM_REGPARM __attribute__((weak)); >>extern void _ITM_memcpyRtWn(void *, const void *, size_t) >> ITM_REGPARM __attribute__((weak)); >>extern void _ITM_memcpyRnWt(void *, const void *, size_t) >> ITM_REGPARM __attribute__((weak)); >>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 > >I think it's better to just drop that whole section of the file if TM >isn't supported, as this patch does. > >Bootstraps OK on AIX, still testing on GNU/Linux. Doh, it causes libitm.c++/libstdc++-safeexc.C to FAIL, because TM isn't enabled when building libstdc++ ... that's the whole point of the complicated preprocessor conditions!
commit 16819a03a27de6911140c8e1a249611dc232b30d
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Sat Jan 16 13:07:02 2016 +0000
Fix bootstrap for targets without TM support
PR libstdc++/69312
* include/bits/c++config: Adjust whitespace.
* libsupc++/eh_exception.cc: Check feature-test macro for TM support.
* src/c++11/cow-stdexcept.cc: Likewise.
diff --git a/libstdc++-v3/include/bits/c++config b/libstdc++-v3/include/bits/c++config
index 387a7bb..81d757e 100644
--- a/libstdc++-v3/include/bits/c++config
+++ b/libstdc++-v3/include/bits/c++config
@@ -490,11 +490,11 @@ namespace std
&& _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
+# define _GLIBCXX_TXN_SAFE transaction_safe
+# define _GLIBCXX_TXN_SAFE_DYN transaction_safe_dynamic
#else
-#define _GLIBCXX_TXN_SAFE
-#define _GLIBCXX_TXN_SAFE_DYN
+# define _GLIBCXX_TXN_SAFE
+# define _GLIBCXX_TXN_SAFE_DYN
#endif
#else // !__cplusplus
diff --git a/libstdc++-v3/libsupc++/eh_exception.cc b/libstdc++-v3/libsupc++/eh_exception.cc
index 32f9df7..f1a6ffb 100644
--- a/libstdc++-v3/libsupc++/eh_exception.cc
+++ b/libstdc++-v3/libsupc++/eh_exception.cc
@@ -51,6 +51,7 @@ std::bad_exception::what() const _GLIBCXX_TXN_SAFE_DYN _GLIBCXX_USE_NOEXCEPT
return "std::bad_exception";
}
+#if __cpp_transactional_memory >= 201505L
// Transactional clones for the destructors and what().
// what() is effectively transaction_pure, but we do not want to annotate it
// as such; thus, we call exactly the respective nontransactional function.
@@ -84,3 +85,4 @@ _ZGTtNKSt13bad_exception4whatEv(
}
}
+#endif
diff --git a/libstdc++-v3/src/c++11/cow-stdexcept.cc b/libstdc++-v3/src/c++11/cow-stdexcept.cc
index afc3f6c..7211ebe 100644
--- a/libstdc++-v3/src/c++11/cow-stdexcept.cc
+++ b/libstdc++-v3/src/c++11/cow-stdexcept.cc
@@ -26,6 +26,7 @@
// ISO C++ 14882: 19.1 Exception classes
//
+#if __cpp_transactional_memory >= 201505L
// Enable hooks for support for the Transactional Memory TS (N4514).
#define _GLIBCXX_TM_TS_INTERNAL
void
@@ -40,6 +41,7 @@ void*
_txnal_logic_error_get_msg(void* e);
void*
_txnal_runtime_error_get_msg(void* e);
+#endif
// All exception classes still use the classic COW std::string.
#define _GLIBCXX_USE_CXX11_ABI 0
@@ -167,6 +169,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
+#if __cpp_transactional_memory >= 201505L
// Support for the Transactional Memory TS (N4514).
//
// logic_error and runtime_error both carry a message in the form of a COW
@@ -440,3 +443,4 @@ CTORDTOR(14overflow_error, std::overflow_error, runtime_error)
CTORDTOR(15underflow_error, std::underflow_error, runtime_error)
}
+#endif