Commit Graph

74 Commits

Author SHA1 Message Date
Saleem Abdulrasool 55410fff8e unwinder: conditionalise availability
__attribute__ (( unavailable )) is for Apple specific builds.  Create a macro
to conditionalise the usage of the macro.  This is to aid in porting the
unwinder to other platforms.

llvm-svn: 192868
2013-10-17 03:57:41 +00:00
Nick Kledzik 312fcd0e1c libcxxabi contains the runtime support for C++. But, as some folks have
realized, it is not complete.  It relies on some _Unwind_* functions to be
supplied by the OS. That means it cannot be ported to platforms that don’t 
already have an unwinder.  

Years ago Apple wrote its own unwinder for MacOSX and iOS.  To make libcxxabi 
complete, Apple has decided the source code for its unwinder can be contributed
to the open source LLVM libcxxabi project, with a dual licensed under LLVM 
and MIT license.

So, I’ve spent some time cleaning up the sources to make them conform with 
LLVM style and to conditionalize the sources in a way that should make it 
easier to port to other platforms.  The sources are in a separate "Unwind" 
directory under "src" in libcxxabi.  

Background:
Most architectures now use "zero cost" exceptions for C++.  The zero cost means
there are no extra instructions executed if no exceptions are thrown.  But if 
an exception is thrown, the runtime must consult side tables and figure out how
to restore registers and "unwind" from the current stack frame to the catch 
clause.  That ability to modify the stack frames and cause the thread to resume 
in a catch clause with all registers restored properly is the main purpose 
of the unwinder.

This unwinder has two levels of API.  The high level APIs are the _Unwind_* 
functions which the cxa_* exception functions in libcxxabi require.  The low 
level APIs are the unw_* functions which are an interface defined by the the 
old HP libunwind project (which shares no code with this unwinder).

llvm-svn: 192136
2013-10-07 21:39:41 +00:00
Howard Hinnant 80fe668394 Tweaks/cleanups provided by Matthew Dempsky
llvm-svn: 184118
2013-06-17 20:25:21 +00:00
Howard Hinnant f2ca35cd79 Add capability to demangle invocation functions for ObjC blocks.
llvm-svn: 179208
2013-04-10 19:44:03 +00:00
Howard Hinnant 4ac72dd982 I've moved __cxa_terminate_handler, __cxa_unexpected_handler and __cxa_new_handler from the public header cxxabi.h into the private header cxa_handlers.hpp. During this move I've also moved them from namespace __cxxabiapple into the global namespace. They are, and have always been extern C and so the namespace (or lack of it) does not affect their ABI. In general external clients should not reference these symbols. They are atomic variables and will be changing into C++11 atomic variables in the future. However for those few clients who really need access to them, their name, mangling, size, alignment and layout will remain stable. You just may need your own declaration of them. Include guards have been added to the private header cxa_exception.hpp. The private header cxa_default_handlers.hpp has been removed and the default handlers are now file-static. Include guards have been added to the private header cxa_handlers.hpp.
llvm-svn: 153039
2012-03-19 16:20:34 +00:00
Howard Hinnant baae2be624 Enable __arm__ on apple
llvm-svn: 152735
2012-03-14 19:30:00 +00:00
Howard Hinnant 49f28b5a47 I had originally made the handler function pointers a static internal detail, not accessible to the outside world. I did this because they must be accessed in a thread-safe manner, and the library provides thread-safe getters and setters for these. However I am at least temporarily making them public and giving them the Apple-extension names. In the future these may disappear again, and I think that would probably be a good idea.
llvm-svn: 151256
2012-02-23 15:32:07 +00:00
Howard Hinnant 995fcc0d49 Add (reluctantly) a namespace alias for __cxxabiv1.
llvm-svn: 150828
2012-02-17 18:45:44 +00:00
Howard Hinnant eaa65afc7b Work on restricting symbol visibility.
llvm-svn: 149633
2012-02-02 20:47:28 +00:00
Howard Hinnant 90ef25c05e Add version number to this library so we can recognize when we're using it.
llvm-svn: 149632
2012-02-02 20:47:05 +00:00
Howard Hinnant 5bbc597f1e Put throw() clauses back on these functions in cxxabi.h. This header must be C++03 compatible and these throw specs are consistent with the current cxxabi.h that Apple ships.
llvm-svn: 149249
2012-01-30 16:02:11 +00:00
Howard Hinnant abc770690a By changing all of the throw() specs to noexcept I've been able to compile and link all of the source files into a dylib. Prior to this substitution the changed functions were calling __cxa_call_unexpected which isn't implemented yet. However in none of these cases do we actaully want __cxa_call_unexpected to be called. Primative buildit script added.
llvm-svn: 148880
2012-01-24 23:42:30 +00:00
Howard Hinnant e04f51662c Added __cxa_increment_exception_refcount, __cxa_decrement_exception_refcount, __cxa_current_primary_exception, __cxa_rethrow_primary_exception
llvm-svn: 147106
2011-12-21 23:32:11 +00:00
Howard Hinnant bf8a39bb94 Fixed several bugs, implemented support for vector types, and cleaned out dead code.
llvm-svn: 146677
2011-12-15 20:02:15 +00:00
Howard Hinnant 49b607a2cd Silence some -Wall warnings pointed out by Marshall Clow
llvm-svn: 137047
2011-08-08 15:49:07 +00:00
Nick Kledzik 2dfc79b19e make cxxabi.h safe for C code to include
llvm-svn: 136682
2011-08-02 05:15:26 +00:00
Nick Kledzik 12a10bc046 make LIBCXXABI_NORETURN be the right attribute
llvm-svn: 136680
2011-08-02 05:01:17 +00:00
Marshall Clow 60fa2d232a Fixed struct/class mismatch for std::type_info and added NORETURN flags
llvm-svn: 135584
2011-07-20 14:27:46 +00:00
Howard Hinnant 471e111324 In cxa_demangle.cpp, rewrite __parse_unresolved_name to reflect updated understanding and sync with updated clang mangling. Also fix think-o in __parse_encoding enabling the parsing of trailing .eh and .b.
llvm-svn: 133632
2011-06-22 19:27:39 +00:00
Howard Hinnant 575498b52f tabs to spaces
llvm-svn: 132729
2011-06-07 19:56:49 +00:00
Nick Lewycky 69e35a7f55 Add support for the ARM EABI variant of the __cxa_guard methods, controlled by
the LIBCXXABI_ARMEABI macro.

llvm-svn: 132723
2011-06-07 18:46:10 +00:00
Marshall Clow ad3dea06a9 Added __cxa_bad_cast and __cxa_bad_typeid and placeholder NORETURN macro
llvm-svn: 132524
2011-06-03 02:04:41 +00:00
Howard Hinnant 4a88971ac1 Introduce cxa_virtual.cpp and cxa_guard.cpp. Contributed by Nick Lewycky, Howard Hinnant and John McCall
llvm-svn: 132009
2011-05-24 22:01:16 +00:00
Howard Hinnant d3da57f99b initial import
llvm-svn: 130921
2011-05-05 15:27:28 +00:00