Obtaining current GCC exception model

gcc, mingw-w64

Solution

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`

Problem

`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?

Original source

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