获取当前的GCC异常模型

问题描述

使用 DWARF2 ， sjlj 构建 g ++ >或 seh 异常模型。 提供了 g ++ 的各种版本有不同的异常模型。我希望能够从 gcc 工具链中确定正在使用的异常模型。是否有一个 g ++ 参数可以转储编译器的默认异常模型？

解决方案

编辑：最初，我正在测试 g ++ -v 中描述的配置标志。正如Jonathon Wakely在评论中指出的那样，这不是一件好事情。

检查方法是编译为assembly：

  struct S {〜S（）; }; 
 void bar（）; 
 void foo（）{
 S s; 
 bar（）; 
 
  

g ++ -S< filename> -o output.s 在它们中有以下异常引用：

MinGW-4.8.1- x86-posix-sjlj ：

  .def ___gxx_personality_sj0; .scl 2; .type 32; .endef 
 .def __Unwind_SjLj_Register; .scl 2; .type 32; .endef 
 .def __Unwind_SjLj_Unregister; .scl 2; .type 32; .endef 
 .def __Unwind_SjLj_Resume; .scl 2; .type 32; .endef 
  

MinGW-4.8.1-x86-posix-矮人：

  .def ___gxx_personality_v0; .scl 2; .type 32; .endef 
 .def __Unwind_Resume; .scl 2; .type 32; .endef 
  

MinGW-4.8.1-x64-win32- sjlj ：

  .def __gxx_personality_sj0; .scl 2; .type 32; .endef 
 .def _Unwind_SjLj_Register; .scl 2; .type 32; .endef 
 .def _Unwind_SjLj_Unregister; .scl 2; .type 32; .endef 
 .def _Unwind_SjLj_Resume; .scl 2; .type 32; .endef 
  

MinGW-4.8.1-x64-posix- seh ：

  .def __gxx_personality_seh0; .scl 2; .type 32; .endef 
 .def _Unwind_Resume; .scl 2; .type 32; .endef 
  

MinGW-4.8.1-x64-posix- sjlj ：

  .def __gxx_personality_sj0; .scl 2; .type 32; .endef 
 .def _Unwind_SjLj_Register; .scl 2; .type 32; .endef 
 .def _Unwind_SjLj_Unregister; .scl 2; .type 32; .endef 
 .def _Unwind_SjLj_Resume; .scl 2; .type 32; .endef 
  

FC17-g ++ - 4.7.2-x64 ：

  .cfi_personality 0x3，__ gxx_personality_v0 
 .globl __gxx_personality_v0 
 call _Unwind_Resume 
  

看起来我们应该搜索 __ gxx_personality _（[az]） （0-9] +），然后比较第一个捕获组：

• v = dwarf


• seh = seh


• sj = sjlj

g++ is built using either the DWARF2, sjlj or seh exception model. MinGW-builds provide various builds of g++ that have different exception models. I would like to be able to determine from the gcc toolchain what exception model is being used. Is there a g++ argument that will dump the default exception model of the compiler?

解决方案

Edit: Originally, I was testing for the configuration flags that are described in g++ -v. As Jonathon Wakely points out in the comments, this is not a good thing to do.

An inspection way to do it is to compile to assembly:

struct S { ~S(); };
void bar();
void foo() {
  S s;
  bar();
}

The result of g++ -S <filename> -o output.s have the following exception references in them:

MinGW-4.8.1-x86-posix-sjlj:

.def    ___gxx_personality_sj0; .scl    2;  .type   32; .endef
.def    __Unwind_SjLj_Register; .scl    2;  .type   32; .endef
.def    __Unwind_SjLj_Unregister;   .scl    2;  .type   32; .endef
.def    __Unwind_SjLj_Resume;   .scl    2;  .type   32; .endef

MinGW-4.8.1-x86-posix-dwarf:

.def    ___gxx_personality_v0;  .scl    2;  .type   32; .endef
.def    __Unwind_Resume;    .scl    2;  .type   32; .endef

MinGW-4.8.1-x64-win32-sjlj:

.def    __gxx_personality_sj0;  .scl    2;  .type   32; .endef
.def    _Unwind_SjLj_Register;  .scl    2;  .type   32; .endef
.def    _Unwind_SjLj_Unregister;    .scl    2;  .type   32; .endef
.def    _Unwind_SjLj_Resume;    .scl    2;  .type   32; .endef

MinGW-4.8.1-x64-posix-seh:

.def    __gxx_personality_seh0; .scl    2;  .type   32; .endef
.def    _Unwind_Resume; .scl    2;  .type   32; .endef

MinGW-4.8.1-x64-posix-sjlj:

.def    __gxx_personality_sj0;  .scl    2;  .type   32; .endef
.def    _Unwind_SjLj_Register;  .scl    2;  .type   32; .endef
.def    _Unwind_SjLj_Unregister;    .scl    2;  .type   32; .endef
.def    _Unwind_SjLj_Resume;    .scl    2;  .type   32; .endef

FC17-g++-4.7.2-x64:

.cfi_personality 0x3,__gxx_personality_v0
.globl  __gxx_personality_v0
call    _Unwind_Resume

Looks like we should search for __gxx_personality_([a-z])(0-9]+) and then compare the first capture group to:

• v = dwarf
• seh = seh
• sj = sjlj

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