Promote `rc` (Windows resource compiler) to a proper Meson language
`rc` is now a first-class Meson language, just like `nasm` or `masm`.
Users can declare it with `project('foo', 'c', 'rc')` or
`add_languages('rc')`, and pass `.rc` files directly as sources to build
targets. The `RCFLAGS` environment variable and
`add_project_arguments(language: 'rc')` now work as expected.
Fix #4736
Once we are making a real language and not hand-rolling a simulacrum of
one, it is easy to support `RCFLAGS`. In fact, it is hard to *forget* to
support `RCFLAGS` --- that's the beauty of using existing abstractions.
This is not the easiest way to fix #4736, but I do think it is the best
way long term, because it helps ensure other deviations from how
language support is supposed to work --- of which a missing `*FLAGS`
variable is just one possible example --- are also far less likely.
The issue I am most worried about is the treatment of `depends` and
`depend_files`. As described in the docs, those have to be
hand-migrated, and the result is slightly different behavior in terms of
which exact build steps depend on what. The lack of fine-grained code of
compilation vs linking build depends, or per-language depends (so we
don't have to make assumptions about compilation units) is certainly
preexisting, and arguably a problem. So one could say well that should
be fixed first before we write our shim.
Implementation details:
**Resource Compiler hierarchy** mirrors the `GnuLikeCompiler` /
`VisualStudioLikeCompiler` split used for C/C++:
- `VisualStudioLikeResourceCompiler` — `/I`, `/fo`, `/nologo`, `.res`
suffix
- `WindowsResourceCompiler` (`rc.exe`)
- `LlvmRcCompiler` (`llvm-rc`)
- `GnuLikeResourceCompiler` — `-I`, `-o`, `.o` suffix
- `WindresCompiler` (`windres`)
- `LlvmWindresCompiler` (`llvm-windres`)
- `WineResourceCompiler` (`wrc`)
**`windows.compile_resources()`** is now a thin deprecated shim that
ensures the `rc` language is detected and returns the source files for
the normal compile pipeline to handle.
Key changes:
- `mesonbuild/compilers/rc.py`: new file with the mixin hierarchy
described above
- `mesonbuild/compilers/detect.py`: `detect_rc_compiler()` function
- `mesonbuild/compilers/compilers.py`: `rc` in `Language`,
`lang_suffixes`, `CFLAGS_MAPPING`; new `get_object_suffix()` on
`Compiler` base class
- `mesonbuild/envconfig.py`: `rc` moved from `ENV_VAR_TOOL_MAP` to
`ENV_VAR_COMPILER_MAP` (supports both `RC` and `WINDRES` env vars)
- `mesonbuild/backend/backends.py`: use `compiler.get_object_suffix()`
for output file extension
- `mesonbuild/backend/ninjabackend.py`: skip link rule generation for
compilers without a linker (`rc`)
- `mesonbuild/modules/windows.py`: simplified from 196 to ~80 lines
Latest Meson version supporting previous Python versions:
Meson is available on PyPI, so it can be installed with pip3 install meson. The exact command to type to install with pip can vary between systems, be sure to use the Python 3 version of pip.
If you wish you can install it locally with the standard Python command:
python3 -m pip install meson
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python3 -m pip install ninja
More on Installing Meson build can be found at the getting meson page.
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./packaging/create_zipapp.py --outfile meson.pyz --interpreter '/usr/bin/env python3' <source checkout>
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meson setup <source directory> <build directory>
Depending on how you obtained Meson the command might also be called meson.py instead of plain meson. In the rest of this document we are going to use the latter form.
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cd <source root> meson setup builddir
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