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[Revised][PATCH] PR41260 link with -no_compact_unwind on darwin10 and later
- From: Jack Howarth <howarth at bromo dot med dot uc dot edu>
- To: gcc-patches at gcc dot gnu dot org
- Cc: mrs at apple dot com, peter at pogma dot com
- Date: Mon, 21 Sep 2009 11:35:09 -0400
- Subject: [Revised][PATCH] PR41260 link with -no_compact_unwind on darwin10 and later
The exception handling tests failing on darwin10 since r147995
are due to the new dwarf unwinding information being added
to describe the function epilog. This breaks the unwinding
under darwin10 since the unwinder used is always from libSystem
(based on that from libgcc in gcc 4.2.1) that doesn't expect
this additional information. The attached patch takes the second
option of passing -no_compact_unwind onto the linkage for darwin10
or later. This eliminates all of the regressions from r147995...
http://gcc.gnu.org/ml/gcc-testresults/2009-09/msg01761.html
and more. While we might be able to use the alternate approach
of suppressing the additional dwarf unwinding information, I fear
that there are other incompatibilities left in the compact
unwinding when it is generated by FSF gcc 4.5 but run with an
unwinder based on gcc 4.2.1. Hence the additional regressions
disappearing when -no_compact_unwind is used.
There still is the question of whether this change should
be extended to all darwin and not just darwin10 or later? The
current patch fixes darwin10 but binaries built with gcc 4.5
on darwin9 and run under darwin10 will still have the offending
dwarf unwinding information present.
Okay for gcc trunk?
Jack
2009-09-20 Peter O'Gorman <peter@pogma.com>
PR middle-end/41260
* gcc/config/darwin.h: Pass -no_compact_unwind to linker
on darwin10 and later since it always uses the unwinder in
libSystem which is derived from the gcc 4.2.1 unwinder.
Index: gcc/config/darwin.h
===================================================================
--- gcc/config/darwin.h (revision 151908)
+++ gcc/config/darwin.h (working copy)
@@ -372,7 +372,9 @@
/* Machine dependent libraries. */
-#define LIB_SPEC "%{!static:-lSystem}"
+#define LIB_SPEC "%{!static:\
+ %:version-compare(>= 10.6 mmacosx-version-min= -no_compact_unwind) \
+ -lSystem}"
/* Support -mmacosx-version-min by supplying different (stub) libgcc_s.dylib
libraries to link against, and by not linking against libgcc_s on