[Bug target/51907] New: SIGSEGV in _Unwind_GetIP

[pluto at agmk dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51907

             Bug #: 51907
           Summary: SIGSEGV in _Unwind_GetIP
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: pl...@agmk.net
            Target: x86_64-w64-mingw32


hi,

the following code compiled for x86_64-w64-mingw32 crashes inside libgcc:

#include <cstdio>
#include <unwind.h>

namespace backtracexx
{
        _Unwind_Reason_Code helper( struct _Unwind_Context* ctx, void* )
        {
                std::printf( "helper( ctx = %p ) => ", (void*)ctx );
                _Unwind_Ptr ip = _Unwind_GetIP( ctx );
                std::printf( "ip = %p\n", (void*)ip );
                return _URC_NO_REASON;
        }
        void scan()
        {
                _Unwind_Backtrace( reinterpret_cast< _Unwind_Trace_Fn >( helper
), 0 );
        }
}

int main()
{
        backtracexx::scan();
}


d:\test>d:\mingw64\bin\x86_64-w64-mingw32-g++ example.cpp -g2 -o example.exe

d:\test>d:\mingw64\bin\x86_64-w64-mingw32-g++ -v
Using built-in specs.
COLLECT_GCC=d:\mingw64\bin\x86_64-w64-mingw32-g++
COLLECT_LTO_WRAPPER=d:/mingw64/bin/../libexec/gcc/x86_64-w64-mingw32/4.7.0/lto-wrapper.exe
Target: x86_64-w64-mingw32
Configured with: ../../../build/gcc/src/configure --target=x86_64-w64-mingw32
--prefix=/c/bb/vista64-mingw32/mingw-x86-x86_64/bu
ild/build/root
--with-sysroot=/c/bb/vista64-mingw32/mingw-x86-x86_64/build/build/root
--enable-languages=all,obj-c++ --enable-fu
lly-dynamic-string --disable-multilib
Thread model: win32
gcc version 4.7.0 20111220 (experimental) (GCC)


(gdb) r
Starting program: d:\test/example.exe
[New Thread 2448.0xaa8]
helper( ctx = 000000000022FDD0 ) =>
Program received signal SIGSEGV, Segmentation fault.
0x000000006cecea63 in _Unwind_GetIP (context=0x22fdd0) at
../../../../../build/gcc/src/libgcc/unwind-sjlj.c:214
214     ../../../../../build/gcc/src/libgcc/unwind-sjlj.c: No such file or
directory.
        in ../../../../../build/gcc/src/libgcc/unwind-sjlj.c
(gdb) bt
#0  0x000000006cecea63 in _Unwind_GetIP (context=0x22fdd0) at
../../../../../build/gcc/src/libgcc/unwind-sjlj.c:214
#1  0x0000000000401529 in backtracexx::helper (ctx=0x22fdd0) at example.cpp:9
#2  0x000000006cecee55 in _Unwind_Backtrace (trace=0x401500
<backtracexx::helper(_Unwind_Context*, void*)>,
    trace_argument=0x0) at ../../../../../build/gcc/src/libgcc/unwind.inc:295
#3  0x0000000000401564 in backtracexx::scan () at example.cpp:15
#4  0x000000000040157d in main () at example.cpp:21