我不是在寻找解决这个问题的方法,只是为了解它的原因。一位同事向我展示了一些代码,这些代码在Visual Studio 2008编译时在Windows Mobile 6 ARMV4I下运行时导致访问冲突。这个相同的代码在x86 Windows下运行良好,他声称它可以在GCC编译的Linux下运行(我还没有验证过)。我将问题提炼到以下代码:
int main( int argc, char* argv[] )
{
try
{
throw std::runtime_error( "a" );
}
catch( std::runtime_error& e1 )
{
try
{
try
{
throw std::runtime_error( "b" );
}
catch( std::runtime_error& e11 )
{
throw;
}
}
catch( std::runtime_error& e12 )
{
e12.what(); // access violation
}
}
return 0;
}
如果不考虑此代码是否合理,有人可以解释在上面的代码中调用std::runtime_error::what()
时导致访问冲突的原因吗?
谢谢, PaulH
编辑: callstack:
test.exe!wmain(int argc = 1, wchar_t** argv = 0x00040080) Line: 169, Byte Offsets: 0xd8 C++
_CallSettingFrame
test.exe!CallCatchBlock(EHExceptionRecord* pExcept = 0x1803eb0c, unsigned long int* pRN = 0x1803fc18, _CONTEXT* pContext = 0x1803f014, _s_FuncInfo* pFuncInfo = 0x00023960, void* handlerAddress = 0x00011494, int CatchDepth = 0, unsigned long int NLGCode = 256) Line: 878, Byte Offsets: 0x258 C++
test.exe!__InternalCxxFrameHandler(EHExceptionRecord* pExcept = 0x1803eb0c, unsigned long int* pRN = 0x1803f2f8, _CONTEXT* pContext = 0x1803f014, _DISPATCHER_CONTEXT* pDC = 0x1803e824, _s_FuncInfo* pFuncInfo = 0x00023960, int CatchDepth = 0) Line: 179, Byte Offsets: 0xfc C++
test.exe!__CxxFrameHandler3(EHExceptionRecord* pExcept = 0x1803eb0c, unsigned long int* pRN = 0x1803f2f8, _CONTEXT* pContext = 0x1803f014, _DISPATCHER_CONTEXT* pDC = 0x1803e824) Line: 242, Byte Offsets: 0x54 C++
0xf000fffc
输出窗口:
RaiseException: Thread=96ec78d0 Proc=80096c70 'test.exe'
AKY=00000801 PC=03f91e7c(coredll.dll+0x00043e7c) RA=88037538(NK.EXE+0x00007538) BVA=00000000 FSR=00000000
RaiseException: Thread=96ec78d0 Proc=80096c70 'test.exe'
AKY=00000801 PC=03f91e7c(coredll.dll+0x00043e7c) RA=88037538(NK.EXE+0x00007538) BVA=00000000 FSR=00000000
RaiseException: Thread=96ec78d0 Proc=80096c70 'test.exe'
AKY=00000801 PC=03f91e7c(coredll.dll+0x00043e7c) RA=88037538(NK.EXE+0x00007538) BVA=00000000 FSR=00000000
Data Abort: Thread=96ec78d0 Proc=80096c70 'test.exe'
AKY=00000801 PC=000114ac(test.exe+0x000014ac) RA=0002095c(test.exe+0x0001095c) BVA=5061654c FSR=00000405
First-chance exception at 0x000114ac in test.exe: 0xC0000005: Access violation reading location 0x5061654c.
EDIT2: Microsoft Connect中有关于此问题的defect report。
答案 0 :(得分:0)
这不是一个答案,但列表太长,无法发表评论。
我在程序集中查找了违规代码的Release版本。见下文。我在正确的指令行上从底部标记了5行AV。
int _tmain(int argc, _TCHAR* argv[])
{
000116E8 mov r12, sp
000116EC stmdb sp!, {r11, r12, lr}
000116F0 add r11, sp, #0xC
000116F4 sub sp, sp, #0x98
000116F8 ldr r3, [pc, #0x10C]
000116FC ldr r3, [r3]
00011700 str r3, [r11, #-0x10]
try
{
throw std::runtime_error( "a" );
00011704 mov r2, #0
00011708 mov r1, #0
0001170C sub r0, r11, #0x84
00011710 bl |std::basic_string<char,std::char_traits<char>,std::allocator<char> >::_Tidy ( 11118h )|
00011714 ldr r1, [pc, #0xEC]
00011718 mov r2, #1
0001171C sub r0, r11, #0x84
00011720 bl |std::basic_string<char,std::char_traits<char>,std::allocator<char> >::assign ( 114d0h )
00011724 sub r1, r11, #0x84
00011728 sub r0, r11, #0x68
0001172C bl |std::runtime_error::runtime_error ( 115ach )|
00011730 ldr r1, [pc, #0xC4]
00011734 sub r0, r11, #0x68
00011738 bl 000118F0
return 0;
0001173C ldr r0, [r11, #-0x10]
00011740 bl 00011C70
00011744 mov r0, #0
}
00011748 sub sp, r11, #0xC
0001174C ldmia sp, {r11, sp, pc}
00011750 andeq r3, r1, r8, ror r0
00011754 andeq r4, r1, r0, ror #3
}
catch( std::runtime_error& e11 )
00011758 str lr, [sp, #-4]!
{
throw;
0001175C mov r1, #0
00011760 mov r0, #0
00011764 bl 000118F0
00011768 andeq r3, r1, r8, ror r0
0001176C andeq r4, r1, r0, ror #3
}
}
catch( std::runtime_error& e12 )
00011770 str lr, [sp, #-4]!
{
e12.what(); // access violation
00011774 ldr r0, e12, #-0xA4
00011778 ldr r3, [r0] // AV
0001177C mov lr, pc
00011780 ldr pc, [r3, #4]
00011784 ldr r0, [pc, #0x78]
00011788 ldr pc, [sp], #4