[PATCH] Fix PR libitm/55693
The attached patch eliminates the failure of the libitm.c++/eh-1.C execution
test on darwin10
and later, PR55693. With the introduction of c++ weak-symbol coalescing in Mac
OS X 10.6, dyld no
longer looks up weak symbols that reside in object files rather than shared
libraries. This prevents
weak symbols for the dummy functions in libgcc/config/darwin-crt-tm.c from
being replaced by those
in the libstdc++ shared library. The solution is not to define these dummy
symbols when targeting
Mac OS X 10.6 or later (where the tool chain properly handles undefined weak
refs in the linker).
Tested on x86_64-apple-darwin10 with Xcode 3.2.6, x86_64-apple-darwin11 and
x86_64-apple-darwin12
with Xcode 4.5.2/4.6. Note that this fix requires functional dynamic lookup of
undefined symbols
which is broken for the buggy linkers in Xcode 4.2 up to but not including
Xcode 4.4 due to
radr://10466868. Since the Xcode 4.x was only briefly available to 10.6 users
and the libitm.c++/eh-1.C
execution test is already broken on 10.6, they should revert to Xcode 3.2.6 to
achieve the fix.
Users on 10.7 and later have access to Xcode 4.4 and later without the
undefined dynamic lookup bug.
Okay for gcc trunk?
Jack
/libgcc
2013-02-06 Iain Sandoe i...@codesourcery.com
Jack Howarth howa...@bromo.med.uc.edu
PR libitm/55693
* config/darwin-crt-tm.c: Provide dummy functions only prior to 10.6.
/gcc
2013-02-06 Iain Sandoe i...@codesourcery.com
Jack Howarth howa...@bromo.med.uc.edu
PR libitm/55693
* gcc/config/darwin.h: Replace ENDFILE_SPEC with TM_DESTRUCTOR and
define ENDFILE_SPEC as TM_DESTRUCTOR.
* config/i386/darwin.h (ENDFILE_SPEC): Use TM_DESTRUCTOR.
Index: libgcc/config/darwin-crt-tm.c
===
--- libgcc/config/darwin-crt-tm.c (revision 195764)
+++ libgcc/config/darwin-crt-tm.c (working copy)
@@ -103,9 +103,12 @@ void __doTMdeRegistrations (void)
_ITM_deregisterTMCloneTable (tmct);
}
+#if defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) \
+__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ 1060
+
/* Provide dummy functions to satisfy linkage for versions of the Darwin
tool-chain that that can't handle undefined weak refs at the link stage.
- ??? Define these dummy functions only when !HAVE_ELF_STYLE_WEAKREF. */
+ Don't define for 10.6 or later with faster weak-symbol coalescing. */
extern void *__cxa_allocate_exception (size_t) WEAK;
extern void __cxa_throw (void *, void *, void *) WEAK;
@@ -144,5 +147,5 @@ void _ZdlPvRKSt9nothrow_t (void * a UNUS
void *_ZnaXRKSt9nothrow_t (size_t s UNUSED, c_nothrow_p b UNUSED)
{ return NULL; }
void _ZdaPvRKSt9nothrow_t (void * a UNUSED, c_nothrow_p b UNUSED) { return; }
-
+#endif
#endif
Index: gcc/config/i386/darwin.h
===
--- gcc/config/i386/darwin.h(revision 195764)
+++ gcc/config/i386/darwin.h(working copy)
@@ -131,8 +131,7 @@ extern int darwin_emit_branch_islands;
%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
%{mpc32:crtprec32.o%s} \
%{mpc64:crtprec64.o%s} \
- %{mpc80:crtprec80.o%s} \
- %{fgnu-tm: -lcrttme.o}
+ %{mpc80:crtprec80.o%s} TM_DESTRUCTOR
#undef SUBTARGET_EXTRA_SPECS
#define SUBTARGET_EXTRA_SPECS \
Index: gcc/config/darwin.h
===
--- gcc/config/darwin.h (revision 195764)
+++ gcc/config/darwin.h (working copy)
@@ -363,7 +363,8 @@ extern GTY(()) int darwin_ms_struct;
%{shared-libgcc:%:version-compare( 10.5 mmacosx-version-min= crt3.o%s)}
/* We want a destructor last in the list. */
-#define ENDFILE_SPEC %{fgnu-tm: -lcrttme.o}
+#define TM_DESTRUCTOR %{fgnu-tm: -lcrttme.o}
+#define ENDFILE_SPEC TM_DESTRUCTOR
#define DARWIN_EXTRA_SPECS \
{ darwin_crt1, DARWIN_CRT1_SPEC }, \
Re: [PATCH] Fix PR libitm/55693
Hi Jack,
Thanks for having a look at this.
However I don't understand why you need this:
Index: gcc/config/i386/darwin.h
===
--- gcc/config/i386/darwin.h (revision 195764)
+++ gcc/config/i386/darwin.h (working copy)
@@ -131,8 +131,7 @@ extern int darwin_emit_branch_islands;
%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
%{mpc32:crtprec32.o%s} \
%{mpc64:crtprec64.o%s} \
- %{mpc80:crtprec80.o%s} \
- %{fgnu-tm: -lcrttme.o}
+ %{mpc80:crtprec80.o%s} TM_DESTRUCTOR
#undef SUBTARGET_EXTRA_SPECS
#define SUBTARGET_EXTRA_SPECS \
Index: gcc/config/darwin.h
===
--- gcc/config/darwin.h (revision 195764)
+++ gcc/config/darwin.h (working copy)
@@ -363,7 +363,8 @@ extern GTY(()) int darwin_ms_struct;
%{shared-libgcc:%:version-compare( 10.5 mmacosx-version-min= crt3.o%s)}
/* We want a destructor last in the list. */
-#define ENDFILE_SPEC %{fgnu-tm: -lcrttme.o}
+#define TM_DESTRUCTOR %{fgnu-tm: -lcrttme.o}
+#define ENDFILE_SPEC TM_DESTRUCTOR
#define DARWIN_EXTRA_SPECS \
{ darwin_crt1, DARWIN_CRT1_SPEC }, \
It seems you just add a macro TM_DESTRUCTOR which is the same as
ENDFILE_SPEC. Maybe I missed something (I am updating my svn)...
Also why HAVE_ELF_STYLE_WEAKREF is not defined for MacOS version where
weak ref works? It could be better to define function to dummy only if
HAVE_ELF_STYLE_WEAKREF is not set (and not testing the MacOS version).
If we want to remove support for Xcode 4.2 (buggy linker), I think you
should also have a look at the old commit to undo it (I remember a
change in libitm which add a #ifdef MACH).
Thanks.
--
Patrick
Re: [PATCH] Fix PR libitm/55693
On Wed, Feb 06, 2013 at 05:37:12PM +0100, Patrick Marlier wrote:
Hi Jack,
Thanks for having a look at this.
However I don't understand why you need this:
Index: gcc/config/i386/darwin.h
===
--- gcc/config/i386/darwin.h (revision 195764)
+++ gcc/config/i386/darwin.h (working copy)
@@ -131,8 +131,7 @@ extern int darwin_emit_branch_islands;
%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
%{mpc32:crtprec32.o%s} \
%{mpc64:crtprec64.o%s} \
- %{mpc80:crtprec80.o%s} \
- %{fgnu-tm: -lcrttme.o}
+ %{mpc80:crtprec80.o%s} TM_DESTRUCTOR
#undef SUBTARGET_EXTRA_SPECS
#define SUBTARGET_EXTRA_SPECS \
Index: gcc/config/darwin.h
===
--- gcc/config/darwin.h (revision 195764)
+++ gcc/config/darwin.h (working copy)
@@ -363,7 +363,8 @@ extern GTY(()) int darwin_ms_struct;
%{shared-libgcc:%:version-compare( 10.5 mmacosx-version-min= crt3.o%s)}
/* We want a destructor last in the list. */
-#define ENDFILE_SPEC %{fgnu-tm: -lcrttme.o}
+#define TM_DESTRUCTOR %{fgnu-tm: -lcrttme.o}
+#define ENDFILE_SPEC TM_DESTRUCTOR
#define DARWIN_EXTRA_SPECS \
{ darwin_crt1, DARWIN_CRT1_SPEC }, \
It seems you just add a macro TM_DESTRUCTOR which is the same as
ENDFILE_SPEC. Maybe I missed something (I am updating my svn)...
Patrick,
This was the patch Iain proposed off-list and I just cleaned up the comments.
I believe that he added the additional definition of TM_DESTRUCTOR so that
it could be used to replace the explicit instance of %{fgnu-tm: -lcrttme.o}
in the definition of ENDFILE_SPEC in gcc/config/i386/darwin.h.
Also why HAVE_ELF_STYLE_WEAKREF is not defined for MacOS version where
weak ref works? It could be better to define function to dummy only if
HAVE_ELF_STYLE_WEAKREF is not set (and not testing the MacOS version).
I assume you are referring to the change...
/* Provide dummy functions to satisfy linkage for versions of the Darwin
tool-chain that that can't handle undefined weak refs at the link stage.
- ??? Define these dummy functions only when !HAVE_ELF_STYLE_WEAKREF. */
+ Don't define for 10.6 or later with faster weak-symbol coalescing. */
As far as I can tell that was only a TODO type note in the comments and
was never implemented. Using !HAVE_ELF_STYLE_WEAKREF as the conditional
to avoid defining the dummy functions won't help at all. The problem here
has nothing to do with HAVE_ELF_STYLE_WEAKREF but is the fact that
the introduction of faster c++ weak-symbol coalescing prevents dyld from
looking in libstdc++ for the __cxa* symbols if weak symbols for them
exist in linked libgcc/config/darwin-crt-tm.o. This problem also exists
for Xcode 3.2.6 which doesn't HAVE_ELF_STYLE_WEAKREF. So the correct fix
is what Iain proposed of defining the dummy functions only when the
__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ 10.6.
If we want to remove support for Xcode 4.2 (buggy linker), I think you
should also have a look at the old commit to undo it (I remember a
change in libitm which add a #ifdef MACH).
I don't see the point. The libitm.c++/eh-1.C execution test case is broken
current gcc trunk on Xcode 4.2 up to 4.4. With the patch, it remains broken (as
you
there are some linker bugs you just can hack around).
Jack
Thanks.
--
Patrick
Re: [PATCH] Fix PR libitm/55693
On 6 Feb 2013, at 17:20, Jack Howarth wrote:
On Wed, Feb 06, 2013 at 05:37:12PM +0100, Patrick Marlier wrote:
Hi Jack,
Thanks for having a look at this.
However I don't understand why you need this:
Index: gcc/config/i386/darwin.h
===
--- gcc/config/i386/darwin.h (revision 195764)
+++ gcc/config/i386/darwin.h (working copy)
@@ -131,8 +131,7 @@ extern int darwin_emit_branch_islands;
%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
%{mpc32:crtprec32.o%s} \
%{mpc64:crtprec64.o%s} \
- %{mpc80:crtprec80.o%s} \
- %{fgnu-tm: -lcrttme.o}
+ %{mpc80:crtprec80.o%s} TM_DESTRUCTOR
#undef SUBTARGET_EXTRA_SPECS
#define SUBTARGET_EXTRA_SPECS \
Index: gcc/config/darwin.h
===
--- gcc/config/darwin.h (revision 195764)
+++ gcc/config/darwin.h (working copy)
@@ -363,7 +363,8 @@ extern GTY(()) int darwin_ms_struct;
%{shared-libgcc:%:version-compare( 10.5 mmacosx-version-min= crt3.o%s)}
/* We want a destructor last in the list. */
-#define ENDFILE_SPEC %{fgnu-tm: -lcrttme.o}
+#define TM_DESTRUCTOR %{fgnu-tm: -lcrttme.o}
+#define ENDFILE_SPEC TM_DESTRUCTOR
#define DARWIN_EXTRA_SPECS \
{ darwin_crt1, DARWIN_CRT1_SPEC }, \
It seems you just add a macro TM_DESTRUCTOR which is the same as
ENDFILE_SPEC. Maybe I missed something (I am updating my svn)...
Patrick,
This was the patch Iain proposed off-list and I just cleaned up the
comments.
I believe that he added the additional definition of TM_DESTRUCTOR so that
it could be used to replace the explicit instance of %{fgnu-tm: -lcrttme.o}
in the definition of ENDFILE_SPEC in gcc/config/i386/darwin.h.
Correct - it was non-obvious to have a second instance embedded in the sub-dir.
(but I'm not going to complain if that change is removed).
==
Apropos support.
I believe our policy is to support the latest official XCode from Apple for
each version of Darwin.
In some cases (Darwins 9) the last issued XCode will not build GCC and it's
neccessary to build odcctools and bootstrap via an older GCC.
but otherwise I don't see a point in trying to support anything that's an
'unofficial developer' release of XCode.
Iain
Re: [PATCH] Fix PR libitm/55693
On Wed, Feb 06, 2013 at 05:28:33PM +, Iain Sandoe wrote:
On 6 Feb 2013, at 17:20, Jack Howarth wrote:
On Wed, Feb 06, 2013 at 05:37:12PM +0100, Patrick Marlier wrote:
Hi Jack,
Thanks for having a look at this.
However I don't understand why you need this:
Index: gcc/config/i386/darwin.h
===
--- gcc/config/i386/darwin.h (revision 195764)
+++ gcc/config/i386/darwin.h (working copy)
@@ -131,8 +131,7 @@ extern int darwin_emit_branch_islands;
%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
%{mpc32:crtprec32.o%s} \
%{mpc64:crtprec64.o%s} \
- %{mpc80:crtprec80.o%s} \
- %{fgnu-tm: -lcrttme.o}
+ %{mpc80:crtprec80.o%s} TM_DESTRUCTOR
#undef SUBTARGET_EXTRA_SPECS
#define SUBTARGET_EXTRA_SPECS \
Index: gcc/config/darwin.h
===
--- gcc/config/darwin.h (revision 195764)
+++ gcc/config/darwin.h (working copy)
@@ -363,7 +363,8 @@ extern GTY(()) int darwin_ms_struct;
%{shared-libgcc:%:version-compare( 10.5 mmacosx-version-min= crt3.o%s)}
/* We want a destructor last in the list. */
-#define ENDFILE_SPEC %{fgnu-tm: -lcrttme.o}
+#define TM_DESTRUCTOR %{fgnu-tm: -lcrttme.o}
+#define ENDFILE_SPEC TM_DESTRUCTOR
#define DARWIN_EXTRA_SPECS \
{ darwin_crt1, DARWIN_CRT1_SPEC }, \
It seems you just add a macro TM_DESTRUCTOR which is the same as
ENDFILE_SPEC. Maybe I missed something (I am updating my svn)...
Patrick,
This was the patch Iain proposed off-list and I just cleaned up the
comments.
I believe that he added the additional definition of TM_DESTRUCTOR so that
it could be used to replace the explicit instance of %{fgnu-tm: -lcrttme.o}
in the definition of ENDFILE_SPEC in gcc/config/i386/darwin.h.
Correct - it was non-obvious to have a second instance embedded in the
sub-dir.
(but I'm not going to complain if that change is removed).
==
Apropos support.
I believe our policy is to support the latest official XCode from Apple for
each version of Darwin.
Iain,
Do remember that Xcode 4.x on Snow Leopard is the odd duck here. Those
releases were the
only Xcode releases that Apple required to be explicitly purchased at a cost
from the App Store.
Also, those releases were only briefly available from the App Store (as they
were removed as
soon as Lion was released). So it is no longer the latest official Xcode for
Snow Leopard
(unless you have a paid developer account). I suspect this episode will never
be repeated and had
more to do with the novelty of the App Store at the time. Apple has been very
good with Xcode
releases under Lion (starting with 4.2 up to the current 4.6 release) all being
free.
Jack
In some cases (Darwins 9) the last issued XCode will not build GCC and it's
neccessary to build odcctools and bootstrap via an older GCC.
but otherwise I don't see a point in trying to support anything that's an
'unofficial developer' release of XCode.
It's really neither fish nor fowl as Apple did release it 'officially' but only
for a brief period of time.
Iain
Re: [PATCH] Fix PR libitm/55693
On Wed, Feb 6, 2013 at 6:28 PM, Iain Sandoe i...@codesourcery.com wrote:
On 6 Feb 2013, at 17:20, Jack Howarth wrote:
On Wed, Feb 06, 2013 at 05:37:12PM +0100, Patrick Marlier wrote:
Hi Jack,
Thanks for having a look at this.
However I don't understand why you need this:
Index: gcc/config/i386/darwin.h
===
--- gcc/config/i386/darwin.h (revision 195764)
+++ gcc/config/i386/darwin.h (working copy)
@@ -131,8 +131,7 @@ extern int darwin_emit_branch_islands;
%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
%{mpc32:crtprec32.o%s} \
%{mpc64:crtprec64.o%s} \
- %{mpc80:crtprec80.o%s} \
- %{fgnu-tm: -lcrttme.o}
+ %{mpc80:crtprec80.o%s} TM_DESTRUCTOR
#undef SUBTARGET_EXTRA_SPECS
#define SUBTARGET_EXTRA_SPECS \
Index: gcc/config/darwin.h
===
--- gcc/config/darwin.h (revision 195764)
+++ gcc/config/darwin.h (working copy)
@@ -363,7 +363,8 @@ extern GTY(()) int darwin_ms_struct;
%{shared-libgcc:%:version-compare( 10.5 mmacosx-version-min= crt3.o%s)}
/* We want a destructor last in the list. */
-#define ENDFILE_SPEC %{fgnu-tm: -lcrttme.o}
+#define TM_DESTRUCTOR %{fgnu-tm: -lcrttme.o}
+#define ENDFILE_SPEC TM_DESTRUCTOR
#define DARWIN_EXTRA_SPECS \
{ darwin_crt1, DARWIN_CRT1_SPEC }, \
It seems you just add a macro TM_DESTRUCTOR which is the same as
ENDFILE_SPEC. Maybe I missed something (I am updating my svn)...
Patrick,
This was the patch Iain proposed off-list and I just cleaned up the
comments.
I believe that he added the additional definition of TM_DESTRUCTOR so that
it could be used to replace the explicit instance of %{fgnu-tm: -lcrttme.o}
in the definition of ENDFILE_SPEC in gcc/config/i386/darwin.h.
Correct - it was non-obvious to have a second instance embedded in the
sub-dir.
(but I'm not going to complain if that change is removed).
I had a look at Iain's patch from the PR but some changes are missing
in the proposed patch to give TM_DESTRUCTOR a sense.
So either you add changes for files: gcc/config/darwin10.h
libgcc/config.host libgcc/config/t-darwin to this patch or you create
another patch with changes to gcc/config/darwin10.h libgcc/config.host
libgcc/config/t-darwin gcc/config/darwin.h gcc/config/i386/darwin.h.
About this old patch
http://gcc.gnu.org/ml/gcc-patches/2012-02/msg00851.html, I though that
!defined (__MACH__) should be changed but it seems the best
way...
Thanks for the precision about XCode.
Note that I cannot approve anything. So the patch must be approved by
a GCC master ;)
--
Patrick
Re: [PATCH] Fix PR libitm/55693
On Wed, Feb 06, 2013 at 09:15:20PM +0100, Patrick Marlier wrote:
On Wed, Feb 6, 2013 at 6:28 PM, Iain Sandoe i...@codesourcery.com wrote:
On 6 Feb 2013, at 17:20, Jack Howarth wrote:
On Wed, Feb 06, 2013 at 05:37:12PM +0100, Patrick Marlier wrote:
Hi Jack,
Thanks for having a look at this.
However I don't understand why you need this:
Index: gcc/config/i386/darwin.h
===
--- gcc/config/i386/darwin.h (revision 195764)
+++ gcc/config/i386/darwin.h (working copy)
@@ -131,8 +131,7 @@ extern int darwin_emit_branch_islands;
%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
%{mpc32:crtprec32.o%s} \
%{mpc64:crtprec64.o%s} \
- %{mpc80:crtprec80.o%s} \
- %{fgnu-tm: -lcrttme.o}
+ %{mpc80:crtprec80.o%s} TM_DESTRUCTOR
#undef SUBTARGET_EXTRA_SPECS
#define SUBTARGET_EXTRA_SPECS \
Index: gcc/config/darwin.h
===
--- gcc/config/darwin.h (revision 195764)
+++ gcc/config/darwin.h (working copy)
@@ -363,7 +363,8 @@ extern GTY(()) int darwin_ms_struct;
%{shared-libgcc:%:version-compare( 10.5 mmacosx-version-min=
crt3.o%s)}
/* We want a destructor last in the list. */
-#define ENDFILE_SPEC %{fgnu-tm: -lcrttme.o}
+#define TM_DESTRUCTOR %{fgnu-tm: -lcrttme.o}
+#define ENDFILE_SPEC TM_DESTRUCTOR
#define DARWIN_EXTRA_SPECS \
{ darwin_crt1, DARWIN_CRT1_SPEC }, \
It seems you just add a macro TM_DESTRUCTOR which is the same as
ENDFILE_SPEC. Maybe I missed something (I am updating my svn)...
Patrick,
This was the patch Iain proposed off-list and I just cleaned up the
comments.
I believe that he added the additional definition of TM_DESTRUCTOR so that
it could be used to replace the explicit instance of %{fgnu-tm: -lcrttme.o}
in the definition of ENDFILE_SPEC in gcc/config/i386/darwin.h.
Correct - it was non-obvious to have a second instance embedded in the
sub-dir.
(but I'm not going to complain if that change is removed).
I had a look at Iain's patch from the PR but some changes are missing
in the proposed patch to give TM_DESTRUCTOR a sense.
So either you add changes for files: gcc/config/darwin10.h
libgcc/config.host libgcc/config/t-darwin to this patch or you create
another patch with changes to gcc/config/darwin10.h libgcc/config.host
libgcc/config/t-darwin gcc/config/darwin.h gcc/config/i386/darwin.h.
Patrick,
I think you are making this much more complex than it really is.
The ENDFILE_SPEC on ppc is obtained from gcc/config/darwin.h and is
only...
#define TM_DESTRUCTOR %{fgnu-tm: -lcrttme.o}
whereas for intel darwin, it is defined in gcc/config/i386/darwin.h as
#undef ENDFILE_SPEC
#define ENDFILE_SPEC \
%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
%{mpc32:crtprec32.o%s} \
%{mpc64:crtprec64.o%s} \
%{mpc80:crtprec80.o%s} \
%{fgnu-tm: -lcrttme.o}
Iain only added TM_DESTRUCTOR to remove the explicit instance of
%{fgnu-tm: -lcrttme.o} in the definition of ENDFILE_SPEC in
gcc/config/i386/darwin.h (which meant he needed a new definition,
TM_DESTRUCTOR).
That change is non-essential to the fix and completely tangential to the
problem. The actual fix is only the change...
Index: libgcc/config/darwin-crt-tm.c
===
--- libgcc/config/darwin-crt-tm.c (revision 195764)
+++ libgcc/config/darwin-crt-tm.c (working copy)
@@ -103,9 +103,12 @@ void __doTMdeRegistrations (void)
_ITM_deregisterTMCloneTable (tmct);
}
+#if defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) \
+__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ 1060
+
/* Provide dummy functions to satisfy linkage for versions of the Darwin
tool-chain that that can't handle undefined weak refs at the link stage.
- ??? Define these dummy functions only when !HAVE_ELF_STYLE_WEAKREF. */
+ Don't define for 10.6 or later with faster weak-symbol coalescing. */
extern void *__cxa_allocate_exception (size_t) WEAK;
extern void __cxa_throw (void *, void *, void *) WEAK;
@@ -144,5 +147,5 @@ void _ZdlPvRKSt9nothrow_t (void * a UNUS
void *_ZnaXRKSt9nothrow_t (size_t s UNUSED, c_nothrow_p b UNUSED)
{ return NULL; }
void _ZdaPvRKSt9nothrow_t (void * a UNUSED, c_nothrow_p b UNUSED) { return; }
-
+#endif
#endif
which correctly eliminates the definition of the dummy functions on darwin
when c++ fast weak-symbol coalescing is present (which was introduced in
dyld at 10.6). The problem and solution was identified by the darwin linker
developer. The fast weak-symbol coalescing now assumes that weak symbol
duplicates are rare and only looks for them if the weak symbol appears
in a shared library. In our case, the weak dummy functions are considered
to reside in an object file, libgcc/config/darwin-crt-tm.o, and this
doesn't trigger the
Re: [PATCH] Fix PR libitm/55693
On Wed, Feb 06, 2013 at 09:15:20PM +0100, Patrick Marlier wrote: About this old patch http://gcc.gnu.org/ml/gcc-patches/2012-02/msg00851.html, I though that !defined (__MACH__) should be changed but it seems the best way... Actually on reflection this conditional may be why the proposed patch doesn't work under 10.6 with Xcode 4.2. That configuration, unlike Xcode 4.5.2/4.6 on 10.7/10.8, doesn't cause HAVE_ELF_STYLE_WEAKREF to be defined and the testcase was failing with undefined symbols for _ZdlPv. Since Xcode 4.2 has an undefined dynamic lookup bug and Iain said the patch worked with Xcode 3.2.6 on 10.6, I didn't explore further. I can test tomorrow removing the !defined (__MACH__) from libitm/eh_cpp.cc and libitm/alloc_cpp.cc to see if that fixes the Xcode 4.2/10.6 combination. However, from the original comments added to the code, this likely will cause the problem with undefined weak refs being improperly handled at link to time to return for older Xcode's. Do we know exactly which Xcode releases show that issue? Jack Thanks for the precision about XCode. Note that I cannot approve anything. So the patch must be approved by a GCC master ;) -- Patrick
Re: [PATCH] Fix PR libitm/55693
Jack,
On Wed, Feb 6, 2013 at 10:27 PM, Jack Howarth howa...@bromo.med.uc.edu wrote:
I think you are making this much more complex than it really is.
The ENDFILE_SPEC on ppc is obtained from gcc/config/darwin.h and is
only...
#define TM_DESTRUCTOR %{fgnu-tm: -lcrttme.o}
whereas for intel darwin, it is defined in gcc/config/i386/darwin.h as
#undef ENDFILE_SPEC
#define ENDFILE_SPEC \
%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
%{mpc32:crtprec32.o%s} \
%{mpc64:crtprec64.o%s} \
%{mpc80:crtprec80.o%s} \
%{fgnu-tm: -lcrttme.o}
Iain only added TM_DESTRUCTOR to remove the explicit instance of
%{fgnu-tm: -lcrttme.o} in the definition of ENDFILE_SPEC in
gcc/config/i386/darwin.h (which meant he needed a new definition,
TM_DESTRUCTOR).
That change is non-essential to the fix and completely tangential to the
problem. The actual fix is only the change...
Ok thanks. I am fine with this then. It was just I did not understand
the purpose of this from your first email on gcc-patches.
--
Patrick
