Re: windows cfbot failing: my_perl

Hi,

On 2022-08-26 06:40:47 -0700, Andres Freund wrote:
> On 2022-08-26 06:21:51 -0700, Andres Freund wrote:
> > On 2022-08-26 06:55:46 -0500, Justin Pryzby wrote:
> > > The last 20 some consecutive builds failed:
> > > https://cirrus-ci.com/github/postgresql-cfbot/postgresql
> > > 
> > > like this:
> > > [09:29:27.711] C:\Program Files (x86)\Windows Kits\10\Include\10.0.20348.0\ucrt\malloc.h(159,17): error C2065: 'my_perl': undeclared identifier (compiling source file src/pl/plperl/SPI.c) [c:\cirrus\plperl.vcxproj]
> > > [09:29:27.711] C:\Program Files (x86)\Windows Kits\10\Include\10.0.20348.0\ucrt\malloc.h(159,17): error C2065: 'my_perl': undeclared identifier (compiling source file src/pl/plperl/Util.c) [c:\cirrus\plperl.vcxproj]
> > > [09:29:27.711] C:\Program Files (x86)\Windows Kits\10\Include\10.0.20348.0\ucrt\malloc.h(159,17): error C2223: left of '->IMem' must point to struct/union (compiling source file src/pl/plperl/SPI.c) [c:\cirrus\plperl.vcxproj]
> > > [09:29:27.711] C:\Program Files (x86)\Windows Kits\10\Include\10.0.20348.0\ucrt\malloc.h(159,17): error C2223: left of '->IMem' must point to struct/union (compiling source file src/pl/plperl/Util.c) [c:\cirrus\plperl.vcxproj]
> > > 
> > > I imagine it may be due to an error hit while rebuilding the ci's docker image.
> > 
> > I don't think it's CI specific, see
> > https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=hamerkop&dt=2022-08-26%2011%3A00%3A11
> > 
> > Looks like the failures might have started with
> > https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=121d2d3d70ecdb2113b340c5f3b99a61341291af
> > based on
> > https://cirrus-ci.com/github/postgres/postgres/
> > 
> > Not immediately obvious why that would be.
> 
> Reproduces in a VM, it starts to fail with that commit. Looks like somehow
> different macros are trampling on each other. Something in perl is interfering
> with msvc's malloc.h, turning
> 
>             if (_Marker == _ALLOCA_S_HEAP_MARKER)
>             {
>                 free(_Memory);
>             }
> into
> 
>             if (_Marker == 0xDDDD)
>             {
>                 (*(my_perl->IMem)->pFree)((my_perl->IMem), (_Memory));
>             }
> 
> after preprocessing. No idea how.

Because perl, extremely unhelpfully, #defines free. Which, not surprisingly,
causes issues when including system headers referencing free as well.

I don't really see a good solution to this other than hoisting the
mb/pg_wchar.h include out to before we include all the perl stuff. That does
fix the issue.

Greetings,

Andres Freund