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gcc/4.7: fix C++ exceptions and pthread_exit()

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Following the introduction of the support for the musl C library, the
support of C++ exceptions or features like pthread_exit() got broken
even with other libraries such as glibc. This was reported as bug #7028.

The problem was caused by the gcc patch needed to add support for
musl, which modified the libgcc/unwind-dw2-fde-dip.c logic to decide
whether USE_PT_GNU_EH_FRAME should be enabled or not. It completely
removed the existing logic, replacing it by a single logic based on
the definition of TARGET_DL_ITERATE_PHDR. However, this constant gets
defined by the configure script only for Solaris, or Linux Musl
platforms. For glibc/uClibc, the configure script does not define it,
and therefore USE_PT_GNU_EH_FRAME is not defined, causing issues with
exception handling.

This patch fixes that by restoring all the logic of
libgcc/unwind-dw2-fde-dip.c, and just adding the musl logic as one
more case.

It has been successfully runtime tested using the two code examples
provided in bug #7208, with uClibc, musl and glibc.

Cc: Krzysztof Wrzalik <kwrzalik@gmail.com>
Cc: David Bachelart <david.bachelart@bbright.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
This commit is contained in:
Thomas Petazzoni 2014-08-15 18:38:02 +02:00 committed by Peter Korsgaard
parent 4bb2a05e81
commit fea35ce673
1 changed files with 23 additions and 38 deletions
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61
package/gcc/4.7.4/900-musl-support.patch
View File

@ -13,6 +13,12 @@ https://bitbucket.org/GregorR/musl-cross/src. Compared to the upstream version:
causing build failure. Bug reported upstream at
https://bitbucket.org/GregorR/musl-gcc-patches/issue/4/musl-gcc-patches-break-the-build-on.
* change the USE_PT_GNU_EH_FRAME logic to keep the existing gcc logic
and only add the musl one as an addition, not as a replacement. Not
doing this breaks C++ exception handling with glibc, because
USE_PT_GNU_EH_FRAME doesn't get defined due to the configure script
not testing dl_iterate_phdr() on any system except Solaris.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
@ -71,7 +77,7 @@ Index: b/gcc/config.gcc
*)
tm_defines="$tm_defines DEFAULT_LIBC=LIBC_GLIBC"
;;
@@ -2092,6 +2095,10 @@
@@ -2091,6 +2094,10 @@
powerpc*-*-linux*paired*)
tm_file="${tm_file} rs6000/750cl.h" ;;
esac
@ -299,46 +305,25 @@ Index: b/libgcc/unwind-dw2-fde-dip.c
===================================================================
--- a/libgcc/unwind-dw2-fde-dip.c
+++ b/libgcc/unwind-dw2-fde-dip.c
@@ -47,28 +47,13 @@
#include "unwind-compat.h"
#include "gthr.h"
-#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
- && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \
- || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG)))
-# define USE_PT_GNU_EH_FRAME
-#endif
-
-#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
- && defined(__FreeBSD__) && __FreeBSD__ >= 7
-# define ElfW __ElfN
-# define USE_PT_GNU_EH_FRAME
-#endif
-
-#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
- && defined(__OpenBSD__)
-# define ElfW(type) Elf_##type
-# define USE_PT_GNU_EH_FRAME
-#endif
-
-#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
- && defined(TARGET_DL_ITERATE_PHDR) \
- && defined(__sun__) && defined(__svr4__)
+#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) && defined(TARGET_DL_ITERATE_PHDR)
@@ -71,6 +71,13 @@
# define USE_PT_GNU_EH_FRAME
+# ifdef __OpenBSD__
+# define ElfW(type) Elf_##typ
+# elif defined(__FreeBSD__) && __FreeBSD__ >= 7
+# define ElfW __ElfN
+# endif
#endif
+/* For musl libc, TARGET_DL_ITERATE_PHDR gets defined by the configure
+ script. */
+#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
+ && defined(TARGET_DL_ITERATE_PHDR)
+# define USE_PT_GNU_EH_FRAME
+#endif
+
#if defined(USE_PT_GNU_EH_FRAME)
#include <link.h>
Index: b/gcc/configure
===================================================================
--- a/gcc/configure
+++ b/gcc/configure
@@ -26787,6 +26787,9 @@
@@ -26791,6 +26791,9 @@
else
gcc_cv_libc_provides_ssp=no
case "$target" in
@ -348,7 +333,7 @@ Index: b/gcc/configure
*-*-linux* | *-*-kfreebsd*-gnu | *-*-knetbsd*-gnu)
# glibc 2.4 and later provides __stack_chk_fail and
# either __stack_chk_guard, or TLS access to stack guard canary.
@@ -26820,6 +26823,7 @@
@@ -26824,6 +26827,7 @@
# <http://gcc.gnu.org/ml/gcc/2008-10/msg00130.html>) and for now
# simply assert that glibc does provide this, which is true for all
# realistically usable GNU/Hurd configurations.
@ -356,7 +341,7 @@ Index: b/gcc/configure
gcc_cv_libc_provides_ssp=yes;;
*-*-darwin* | *-*-freebsd*)
ac_fn_c_check_func "$LINENO" "__stack_chk_fail" "ac_cv_func___stack_chk_fail"
@@ -26902,6 +26906,9 @@
@@ -26906,6 +26910,9 @@
gcc_cv_target_dl_iterate_phdr=no
fi
;;
@ -370,7 +355,7 @@ Index: b/gcc/configure.ac
===================================================================
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -4664,6 +4664,9 @@
@@ -4669,6 +4669,9 @@
gcc_cv_libc_provides_ssp,
[gcc_cv_libc_provides_ssp=no
case "$target" in
@ -380,7 +365,7 @@ Index: b/gcc/configure.ac
*-*-linux* | *-*-kfreebsd*-gnu | *-*-knetbsd*-gnu)
[# glibc 2.4 and later provides __stack_chk_fail and
# either __stack_chk_guard, or TLS access to stack guard canary.
@@ -4697,6 +4700,7 @@
@@ -4702,6 +4705,7 @@
# <http://gcc.gnu.org/ml/gcc/2008-10/msg00130.html>) and for now
# simply assert that glibc does provide this, which is true for all
# realistically usable GNU/Hurd configurations.
@ -388,7 +373,7 @@ Index: b/gcc/configure.ac
gcc_cv_libc_provides_ssp=yes;;
*-*-darwin* | *-*-freebsd*)
AC_CHECK_FUNC(__stack_chk_fail,[gcc_cv_libc_provides_ssp=yes],
@@ -4762,6 +4766,9 @@
@@ -4767,6 +4771,9 @@
gcc_cv_target_dl_iterate_phdr=no
fi
;;