On 16 Nov 2011, at 19:12, Richard Henderson wrote:
On 11/16/2011 08:38 AM, Rainer Orth wrote:
* config/generic/asmcfi.h: Fix comment.
* config/x86/sjlj.S (_ITM_beginTransaction): Provide PIC code
sequence without .hidden support.
(GTM_longjmp) [__ELF__]: Only use .hidden if
HAVE_ATTRIBUTE_VISIBILITY.
Nearly ok.
+ subl $4, %esp
+ movl %ebx, 24(%esp)
+ call 1f
+1: popl %ebx
+ addl $_GLOBAL_OFFSET_TABLE_+[.-1b], %ebx
+ call GTM_begin_transaction@PLT
+ movl 24(%esp), %ebx
+ addl $4, %esp
This is overly complicated. We've saved %ebx at 12(%esp) above.
This should be as simple as
call 1f
1: popl %ebx
addl $_GLOBAL_OFFSET_TABLE_+[.-1b], %ebx
call GTM_begin_transaction@PLT
movl 12(%esp), %ebx
It also needs wrapping like
#elif defined(__ELF__)
...
#else
# error "Unsupported PIC sequence"
#endif
... which will almost certainly immediately fail on Darwin, but
at least not with some reference to @PLT.
we have the equivalent of hidden on Darwin :
.private_extern
I will try and get back to this .. been busy with other stuff....
at the moment the two things top issues remaining on Darwn are:
1. underscores for the ASM functions.
.. Darwin's asm will not add an underscore to functions .. so we end
up with unresolved refs to __ITM_beginTransaction/GTM_...
2. providing a section name for .tm_clone_section that is compatible
with Mach-o section semantics.
I've hacked around this for my tests by making a target macro, but
maybe you have some other preference.
Iain
