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Re: [MinGW] Allow Building GCC with --disable-sjlj-exceptions

References: <>

Hello Ranjit, Brian

Brian Dessent wrote:
> Ranjit Mathew wrote:
>> -#define DWARF2_UNWIND_INFO 0
>> +#define DWARF2_UNWIND_INFO 1
> This makes no sense at all.  DW2 EH is seriously broken under
> cygwin/mingw, and it's not clear that this is even fundamentally
> (e.g. the situation of throwing an exception in a callback from third
> party code that doesn't use DW2 like the win32 API.)  Someone posted
> the mingw list recently with a testcase showing even further breakage
> DW2 EH when throwing across a DLL boundary.  Flipping this switch
> be the *last* step that happens after all these other problems are
> fixed, not the first step.  SJLJ is still the only sane default for
> cygwin/mingw.

I would disagree about the "seriously broken". I have been using it in
my own gcc toolset on mingw for three years and I am convinced that it
has more benefits than deficiencies. 

The report of "even further breakage" was actually exciting to me
because the reporter cared enough to also submit a tidy little testcase
Now we can fix the bug. (FWIW, a very similar initialization bug was
reported on the mingw list when the experimental EH-acoss-DLL-boundaries
-- using SjLj -- was first unleashed on mingw users for testing.)

I agree with Ranjit that the option to enable DW2 EH should be made
available on mingw32 target.

But I think it should wait until stage 1.



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