https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108300
Bug ID: 108300
Summary: `abort()` macro cause bootstrap failure on
*-w64-mingw32
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: bootstrap
Assignee: unassigned at gcc dot gnu.org
Reporter: lh_mouse at 126 dot com
Target Milestone: ---
Recently, mingw-w64 has got updated <msxml.h> from Wine. GCC then ceases to
build:
```
../../gcc/gcc/system.h:791:30: error: expected identifier before string
constant
791 | #define abort() fancy_abort (__FILE__, __LINE__, __FUNCTION__)
| ^~~~~~~~
```
The reason is elaborated in this piece of log of #gcc on OFTC:
```
[16:51:28] <lh_ideapad> on Windows hosts, <windows.h> now involves <msxml.h>,
which brings a struct that has `abort()` as a member function, so if the macro
above is expanded there it will become nonsense.
[16:52:34] <lh_ideapad> if GCC does not use that struct (and a plenty more) the
standard way to prevent them from being included is to define
`WIN32_LEAN_AND_MEAN` before inclusion of <windows.h>. unfortunately, not all
GCC source files do so.
[16:53:31] <lh_ideapad> there are about thirty to forty files that include
<windows.h> without defining `WIN32_LEAN_AND_MEAN`. do you think it is a good
idea to patch them all?
[16:54:11] <lh_ideapad> this can be generated by an sed command, but it's gonna
be a large patch, touching files that I am not familiar with.
[16:55:03] <lh_ideapad> or, we can patch mingw-w64 msxml.h to `#undef abort`.
[16:57:22] <iains> can you fixincludes windows.h to add a wrapperr that defines
WIN32_LEAN_AND_MEAN and then include_next windows.h?
[16:58:11] <iains> (that means you do not have to patch the original file ..
you could also use fixincludes to do that too - but it seems maybe more
complicated than the wrapper)
[17:06:14] <iains> .. of course, that does not help if the files are sources
that need to be built by the bootstrap compiler - it’s only going to succeed if
they are all target-libs related.
[17:23:52] <iains> .. hmm but if they are sources in the gcc tree, I’d suppose
that windows.h should not be included directly - but via system.h where you
could place the #define before the inclusion.
[17:34:14] <Arsen> ugh, the wonders of macros
[17:34:25] <Arsen> maybe that can be a static inline fn instead?
[17:34:41] <Arsen> (or even just regular ol inline)
[18:08:19] <jwakely> yeah, GCC should not #define abort like that, it's
disgusting
[18:08:40] <jwakely> "but we've always done it like that" - time to stop
```
I create this PR for the record. In my opinion, including <windows.h> without
`WIN32_LEAN_AND_MEAN` pulls in tons of unnecessary stuff and is almost never
desired. This can be fixed by
```
sed -Ei 's,^( *)#( *)include <windows\.h>,\1#\2define WIN32_LEAN_AND_MEAN
1\n&,' \
$(grep --inc "*.[hc]" --inc "*.cc" -Flr "<windows.h>")
```
(Some source files already have it.)
