On 04/08/16 20:01 +0300, Gleb Natapov wrote:
Instead of throwing an exception allocate its memory and initialize it
explicitly. Makes std::make_exception_ptr more efficient since no stack
unwinding is needed.
In this version I hopefully addressed all Jonathan comments.
* libsupc++/exception (std::exception): Move...
* libsupc++/exception.h: ...here; New.
* libsupc++/cxxabi.h (__cxa_allocate_exception): Move...
* libsupc++/cxxabi_init_exception.h: ...here and add
__cxa_init_primary_exception; New.
* config/abi/pre/gnu-versioned-namespace.ver: add
__cxa_init_primary_exception and std::exception_ptr(void*)
* config/abi/pre/gnu.ver (CXXABI_1.3.11) : add
__cxa_init_primary_exception and std::exception_ptr(void*)
(CXXABI_1.3.11): New.
* include/Makefile.am: add exception.h and cxxabi_init_exception.h
* include/Makefile.in: Likewise.
* libsupc++/Makefile.am: add exception.h and cxxabi_init_exception.h
* libsupc++/Makefile.in: Likewise.
* libsupc++/eh_throw.cc(__cxa_throw): add __cxa_init_primary_exception
and use it
* libsupc++/exception_ptr.h(std::make_exception_ptr): use
__cxa_allocate_exception and __cxa_init_primary_exception to create
exception pointer
* libsupc++/typeinfo: include bits/exception.h instead of exception
This version is *much* easier to review :-)
+namespace __cxxabiv1
+{
+ struct __cxa_refcounted_exception;
+
+ extern "C"
+ {
+ // Allocate memory for the primary exception plus the thrown object.
+ void*
+ __cxa_allocate_exception(size_t) _GLIBCXX_NOTHROW;
Please align __cxa_allocate_exception with the return type on the
previous line.
+
+ // Initialize exception
Please add "(this is a GNU extension)" to the comment.
+ __cxa_refcounted_exception*
+ __cxa_init_primary_exception(void *object, std::type_info *tinfo,
+ void (_GLIBCXX_CDTOR_CALLABI *dest) (void *)) _GLIBCXX_NOTHROW;
+
+ }
+} // namespace __cxxabiv1
+
+#endif
+
+#pragma GCC visibility pop
+
+#endif // _CXXABI_INIT_EXCEPTION_H
index 63631f6..8be903b 100644
--- a/libstdc++-v3/libsupc++/exception
+++ b/libstdc++-v3/libsupc++/exception
@@ -36,39 +36,12 @@
#include <bits/c++config.h>
#include <bits/atomic_lockfree_defines.h>
+#include <bits/exception.h>
extern "C++" {
namespace std
{
- /**
- * @defgroup exceptions Exceptions
- * @ingroup diagnostics
- *
- * Classes and functions for reporting errors via exception classes.
- * @{
- */
The Doxygen group that starts with @{ ends later in this file, but you
haven't moved the corresponding @} to the new file.
I can take care of fixing that up though (we want the contents of the
new file and this one to all be in the group).
@@ -162,8 +169,12 @@ namespace std
swap(exception_ptr& __lhs, exception_ptr& __rhs)
{ __lhs.swap(__rhs); }
- } // namespace __exception_ptr
+ template<typename _Ex>
+ static inline void
+ __dest_thunk(void* x)
+ { reinterpret_cast<_Ex*>(x)->~_Ex(); }
This is still 'static' so we get a separate instantiation in every
translation unit that uses make_exception_ptr. It should non 'inline'
but not 'static'.
Looking at it again now, is there any reason to use reinterpret_cast
rather than static_cast? I think they're identical in this context,
and I prefer not to only use reinterpret_cast as a last resort.
Other than that, I think this is good to commit.
I can't think of any way to test the changes beyond the existing tests
for exception_ptr, so we don't need new test files.
