2.4.0 plan for #12215 [LyX crashes with async processes (Qt6 only)] ?

[Jean-Marc Lasgouttes]

Le 23/11/2022 à 04:13, Richard Kimberly Heck a écrit :
> In general, from the LyX bug report, it looks like they're building LyX 
> but not Qt with debug iterators enabled.
> 
> That is a bad idea. libstdc++ debug mode breaks ABI. I don't think we 
> ever return any QMap in Qt across its library boundary, but if we did, 
> they couldn't use it.

> So, maybe the problem is very specific to --enable-stdlib-debug and has 
> to do with the way we use external libraries.

It might be time to dump debug iterators and use the less annoying but 
less powerful _GLIBCXX_ASSERTIONS, which only does basic index checking.
It seems to me that most interesting errors found by stdlib-debug in the 
past were in this category.

It was introduced in gcc 6 and the release notes say:
"Assertions to check function preconditions can be enabled by defining 
the _GLIBCXX_ASSERTIONS macro. The initial set of assertions are a 
subset of the checks enabled by the Debug Mode, but without the ABI 
changes and changes to algorithmic complexity that are caused by 
enabling the full Debug Mode. "

As far as I understand, this avoids all compatibility issues. I put 
documentation below; currently we use _GLIBCXX_DEBUG and
_GLIBCXX_DEBUG_PEDANTIC.

JMarc


_GLIBCXX_ASSERTIONS

     Undefined by default. When defined, enables extra error checking in 
the form of precondition assertions, such as bounds checking in strings 
and null pointer checks when dereferencing smart pointers.

_GLIBCXX_DEBUG

     Undefined by default. When defined, compiles user code using the 
debug mode. When defined, _GLIBCXX_ASSERTIONS is defined automatically, 
so all the assertions enabled by that macro are also enabled in debug 
mode. [*]

_GLIBCXX_DEBUG_PEDANTIC

     Undefined by default. When defined while compiling with the debug 
mode, makes the debug mode extremely picky by making the use of 
libstdc++ extensions and libstdc++-specific behavior into errors.


[*] https://gcc.gnu.org/onlinedocs/libstdc++/manual/debug_mode.html