http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55909
Bug #: 55909
Summary: libtool test exposes what I think is some alignment
issue in libstd++
Classification: Unclassified
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: philip.copel...@oracle.com
Created attachment 29107
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29107
Original libtool cpp file
While debugging libtool breakage on sparc64 (64bit Big Endian)
gcc-4.7.2-8.fc18.sparc64
glibc-2.16-28.fc18.sparc64
[mockbuild@localhost 104]$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/sparc64-redhat-linux/4.7.2/lto-wrapper
Target: sparc64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla
--enable-bootstrap --enable-shared --enable-threads=posix
--enable-checking=release --disable-build-with-cxx
--disable-build-poststage1-with-cxx --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-gnu-unique-object
--enable-linker-build-id --with-linker-hash-style=gnu
--enable-languages=c,c++,objc,obj-c++,java,fortran,lto --enable-plugin
--enable-initfini-array --enable-java-awt=gtk --disable-dssi
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre
--enable-libgcj-multifile --with-ecj-jar=/usr/share/java/eclipse-ecj.jar
--disable-libjava-multilib --with-ppl --with-cloog --with-long-double-128
--with-cpu=ultrasparc --disable-multilib --build=sparc64-redhat-linux
Thread model: posix
gcc version 4.7.2 20121109 (Red Hat 4.7.2-8) (GCC)
-------------------------------------------------------------------------------
++ at_fn_check_prepare_dynamic 'if /builddir/build/BUILD/libtool-2.4.2/libtool
--mode=execute -dlopen m/module.la "./main" ; then :; else lt_status=0;
test "Xsparc64-redhat-linux-gnu" != "Xsparc64-redhat-linux-gnu" && test -x
"./main" && exit 77; exit ; fi' exceptions.at:385
++ case $1 in
++ at_fn_check_prepare_trace exceptions.at:385
++ printf '%s\n' exceptions.at:385
++ at_check_trace=:
++ at_check_filter=:
++ :
++ :
++ at_status=139
++ at_failed=false
++ :
++ echo stderr:
stderr:
++ cat
/builddir/build/BUILD/libtool-2.4.2/tests/testsuite.dir/at-groups/104/stderr
++ :
++ /builddir/build/BUILD/libtool-2.4.2/libtool --mode=execute -dlopen
m/module.la ./main
exceptions_in_prog
/builddir/build/BUILD/libtool-2.4.2/tests/testsuite.dir/at-groups/104/test-source:
line 565: 61893 Segmentation fault (core dumped) $LIBTOOL --mode=execute
-dlopen m/module.la "$lt_exe"
++ lt_status=139
------------------------------------------------------------------------------
This eventually boils down to
[mockbuild@localhost 104]$ /builddir/build/BUILD/libtool-2.4.2/libtool
--verbose --mode=execute -dlopen m/module.la ./.libs/lt-main
exceptions_in_prog
Segmentation fault (core dumped)
[mockbuild@localhost 104]$ gdb ./.libs/lt-main
(gdb) set environment LD_LIBRARY_PATH=m
(gdb) run
exceptions_in_prog
Program received signal SIGSEGV, Segmentation fault.
0xfffff8010061a558 in __frame_dummy_init_array_entry () from
/lib64/libstdc++.so.6
(gdb) where
#0 0xfffff8010061a558 in __frame_dummy_init_array_entry () from
/lib64/libstdc++.so.6
#1 0xfffff80100490988 in __cxxabiv1::__cxa_get_globals ()
at ../../../../libstdc++-v3/libsupc++/eh_globals.cc:63
#2 0xfffff801004907cc in std::uncaught_exception ()
at ../../../../libstdc++-v3/libsupc++/eh_catch.cc:136
#3 0xfffff801004ccbe4 in ~sentry (this=0x7fefffff1b0, __in_chrg=<optimized
out>)
at
/usr/src/debug/gcc-4.7.2-20121109/obj-sparc64-redhat-linux/sparc64-redhat-linux/libstdc++-v3/include/ostream:429
#4 std::__ostream_insert<char, std::char_traits<char> > (__out=...,
__s=<optimized out>,
__n=<optimized out>)
at
/usr/src/debug/gcc-4.7.2-20121109/obj-sparc64-redhat-linux/sparc64-redhat-linux/libstdc++-v3/include/bits/ostream_insert.h:112
#5 0x000000000010321c in operator<< <std::char_traits<char> > (
__s=0x1085f8 "exceptions_in_prog\n", __out=...)
at
/usr/lib/gcc/sparc64-redhat-linux/4.7.2/../../../../include/c++/4.7.2/ostream:533
#6 exceptions_in_prog () at main.cpp:30
#7 0x0000000000102e78 in main () at main.cpp:120
-------------------------------------------------------------------------------
Lets read that in order with some program text around it that might make some
better sense:
#7 0x0000000000102e78 in main () at main.cpp:120
(gdb) list
115 int main (void)
116 {
117
118 LTDL_SET_PRELOADED_SYMBOLS();
119
120 if (exceptions_in_prog ())
121 return 1;
122 if (exceptions_in_lib ())
123 return 1;
124 if (exceptions_in_module ())
#6 exceptions_in_prog () at main.cpp:30
(gdb) list
25 return 0;
26 }
27
28 int exceptions_in_prog (void)
29 {
30 std::cerr << "exceptions_in_prog\n";
31 try {
32 foo ();
33 }
34 catch (exc e) {
#5 0x000000000010321c in operator<< <std::char_traits<char> > (
__s=0x1085f8 "exceptions_in_prog\n", __out=...)
at
/usr/lib/gcc/sparc64-redhat-linux/4.7.2/../../../../include/c++/4.7.2/ostream:533
533 __ostream_insert(__out, __s,
(gdb) list
528 operator<<(basic_ostream<char, _Traits>& __out, const char* __s)
529 {
530 if (!__s)
531 __out.setstate(ios_base::badbit);
532 else
533 __ostream_insert(__out, __s,
534
static_cast<streamsize>(_Traits::length(__s)));
535 return __out;
536 }
537
(gdb) down
#4 std::__ostream_insert<char, std::char_traits<char> > (__out=...,
__s=<optimized out>,
__n=<optimized out>)
at
/usr/src/debug/gcc-4.7.2-20121109/obj-sparc64-redhat-linux/sparc64-redhat-linux/libstdc++-v3/include/bits/ostream_insert.h:112
112 return __out;
(gdb) list
107 __throw_exception_again;
108 }
109 __catch(...)
110 { __out._M_setstate(__ios_base::badbit); }
111 }
112 return __out;
113 }
114
115 // Inhibit implicit instantiations for required instantiations,
116 // which are defined via explicit instantiations elsewhere.
#3 0xfffff801004ccbe4 in ~sentry (this=0x7fefffff1b0, __in_chrg=<optimized
out>)
at
/usr/src/debug/gcc-4.7.2-20121109/obj-sparc64-redhat-linux/sparc64-redhat-linux/libstdc++-v3/include/ostream:429
429 if (bool(_M_os.flags() & ios_base::unitbuf) &&
!uncaught_exception())
(gdb) list
424 * @c flush() on the output stream.
425 */
426 ~sentry()
427 {
428 // XXX MT
429 if (bool(_M_os.flags() & ios_base::unitbuf) &&
!uncaught_exception())
430 {
431 // Can't call flush directly or else will get into
recursive lock.
432 if (_M_os.rdbuf() && _M_os.rdbuf()->pubsync() == -1)
433 _M_os.setstate(ios_base::badbit);
#2 0xfffff801004907cc in std::uncaught_exception ()
at ../../../../libstdc++-v3/libsupc++/eh_catch.cc:136
136 __cxa_eh_globals *globals = __cxa_get_globals ();
(gdb) list
131
132
133 bool
134 std::uncaught_exception() throw()
135 {
136 __cxa_eh_globals *globals = __cxa_get_globals ();
137 return globals->uncaughtExceptions != 0;
138 }
#1 0xfffff80100490988 in __cxxabiv1::__cxa_get_globals ()
at ../../../../libstdc++-v3/libsupc++/eh_globals.cc:63
63 { return get_global(); }
(gdb) list
58 __cxxabiv1::__cxa_get_globals_fast() _GLIBCXX_NOTHROW
59 { return get_global(); }
60
61 extern "C" __cxa_eh_globals*
62 __cxxabiv1::__cxa_get_globals() _GLIBCXX_NOTHROW
63 { return get_global(); }
64
65
66 #else
67
#0 0xfffff8010061a558 in __frame_dummy_init_array_entry () from
/lib64/libstdc++.so.6
(gdb) list
68 // Single-threaded fallback buffer.
69 static __cxa_eh_globals eh_globals;
70
71 #if __GTHREADS
72
73 static void
74 eh_globals_dtor(void* ptr)
75 {
76 if (ptr)
77 {
-------------------------------------------------------------------------------
I suspect this may be an endian/alignment bug as the same g++ program will run
correctly on an x86_64 system, however my c++ foo is somewhat weak when it
comes to the lower levels. The above is about as far as I can debug this.
