ODFstudio/odfstudio
2
0
Fork 0
Code Issues Packages Activity

Hack to dynamically adapt to __cxa_exceptiom in LLVM 5.0 libcxxabi

Browse Source 
...for Linux aarch64, similar to 7a9dd3d482 "Hack
to dynamically adapt to __cxa_exceptiom in LLVM 5.0 libcxxabi" for macOS x86-64.
But unlike on macOS (which is known to always use libcxxabi), be careful to only
execute the hack in builds targeting libcxxabi.

Change-Id: I5417fde425d2d6bac9400592193a9fe5d2bfe175
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/88458
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
This commit is contained in:
Stephan Bergmann
2020-02-12 09:11:45 +01:00
parent d1378b92c6
commit a7d1fed245
1 changed files with 22 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
bridges/source/cpp_uno/gcc3_linux_aarch64/abi.cxx
+22
View File
@@ -136,6 +136,28 @@ std::type_info * getRtti(typelib_TypeDescription const & type) {
extern "C" void _GLIBCXX_CDTOR_CALLABI deleteException(void * exception) {
__cxxabiv1::__cxa_exception * header =
static_cast<__cxxabiv1::__cxa_exception *>(exception) - 1;
#if defined _LIBCPPABI_VERSION // detect libc++abi
// The libcxxabi commit
// <http://llvm.org/viewvc/llvm-project?view=revision&revision=303175>
// "[libcxxabi] Align unwindHeader on a double-word boundary" towards
// LLVM 5.0 changed the size of __cxa_exception by adding
//
// __attribute__((aligned))
//
// to the final member unwindHeader, on x86-64 effectively adding a hole of
// size 8 in front of that member (changing its offset from 88 to 96,
// sizeof(__cxa_exception) from 120 to 128, and alignof(__cxa_exception)
// from 8 to 16); a hack to dynamically determine whether we run against a
// new libcxxabi is to look at the exceptionDestructor member, which must
// point to this function (the use of __cxa_exception in fillUnoException is
// unaffected, as it only accesses members towards the start of the struct,
// through a pointer known to actually point at the start):
if (header->exceptionDestructor != &deleteException) {
header = reinterpret_cast<__cxa_exception const *>(
reinterpret_cast<char const *>(header) - 8);
assert(header->exceptionDestructor == &deleteException);
}
#endif
OUString unoName(toUnoName(header->exceptionType->name()));
typelib_TypeDescription * td = 0;
typelib_typedescription_getByName(&td, unoName.pData);