Cannot compile Windows RC file with Meson git

[lb90]

Describe the bug

Compiling GLib on Windows with MSVC fails with the following error:

Compiling C object glib/glib.rc_i.p/glib.rc.i
FAILED: glib/glib.rc_i.p/glib.rc.i
"cl" "/EP" "/P" "-Iglib\glib.rc_i.p" "-Iglib" "-I..\glib\glib" "/MD" "/nologo" "/showIncludes" "/utf-8" "/W4" "/O2" "/Z7" "/FIglib/msvc_recommended_pragmas.h" "/utf-8" "-D_GNU_SOURCE" "-DUNICODE" "-D_UNICODE" "-DG_ENABLE_DEBUG" "/wo4057" "/wd4068" "/wo4090" "/wd4100" "/wd4116" "/wo4125" "/wd4127" "/wd4146" "/wd4152" "/wd4201" "/wd4232" "/wo4245" "/wo4267" "/wd4334" "/wo4389" "/wo4702" "/wd4706" "-DRC_INVOKED" "/Fdglib\glib.rc_i.p\glib.rc.pdb" /Figlib/glib.rc_i.p/glib.rc.i "/c" glib/glib.rc
glib.rc
glib/glib.rc: fatal error C1083: Cannot open include file: 'glib/msvc_recommended_pragmas.h': No such file or directory
ninja: build stopped: subcommand failed.

To Reproduce

• Open either CMD or PowerShell
• python C:\path\to\meson-git\meson.py setup ..\glib --vsenv
• python C:\path\to\meson-git\meson.py compile

Expected behavior

Compilation should succeed as in Meson 1.9.1

system parameters

• Native build
• Windows 11
• Python 3.14
• Meson master
• ninja 1.13.1

[lb90]

This was bisected to 632115e

[bonzini]

@bruchar1

[bruchar1]

It seems to be an include path problem.

[dcbaker]

(Adding branches and tags to help make sure this doesn't get missed before 1.10.0)

[bruchar1]

I was able to reproduce. However, I'm not sure to understand how to solve it...

[lb90]

Hi @bruchar1, thanks for looking into this! :)

I think we can modify things on the GLib side if needed. Could you explain what's happening under the hood?

[lb90]

I think that:

• In Meson 1.9.1, options added via add_project_options('...', language: 'c') do not influence compilation of RC files in any way
• In Meson git, options added via add_project_options('...', language: 'c') end up in the depfile target for RC files

Perhaps we can invoke the preprocessor via CUSTOM_COMMAND rather than c_PREPROCESSOR?

[bonzini]

That's a separate issue, which is not as serious a bug. But if there's no idea on how to fix this the original PR should be reverted.