Add cc.preprocess() method for c-like compilers

This introduce a new type of BuildTarget: CompileTarget. From ninja
backend POV it is the same thing as any other build target, except that
it skips the final link step. It could be used in the future for
transpilers too.

1 files changed, 38 insertions, 0 deletions

diff --git a/mesonbuild/interpreter/compiler.py b/mesonbuild/interpreter/compiler.py
index b46e502..7397321 100644
--- a/mesonbuild/interpreter/compiler.py
+++ b/mesonbuild/interpreter/compiler.py
@@ -4,6 +4,7 @@
 
 import enum
 import functools
+import os
 import typing as T
 
 from .. import build
@@ -79,6 +80,11 @@ if T.TYPE_CHECKING:
         header_prefix: str
         header_required: T.Union[bool, coredata.UserFeatureOption]
 
+    class PreprocessKW(TypedDict):
+        output: str
+        compile_args: T.List[str]
+        include_directories: T.List[build.IncludeDirs]
+
 
 class _TestMode(enum.Enum):
 
@@ -184,6 +190,7 @@ class CompilerHolder(ObjectHolder['Compiler']):
                              'first_supported_link_argument': self.first_supported_link_argument_method,
                              'symbols_have_underscore_prefix': self.symbols_have_underscore_prefix_method,
                              'get_argument_syntax': self.get_argument_syntax_method,
+                             'preprocess': self.preprocess_method,
                              })
 
     @property
@@ -734,3 +741,34 @@ class CompilerHolder(ObjectHolder['Compiler']):
     @noKwargs
     def get_argument_syntax_method(self, args: T.List['TYPE_var'], kwargs: 'TYPE_kwargs') -> str:
         return self.compiler.get_argument_syntax()
+
+    @FeatureNew('compiler.preprocess', '0.64.0')
+    @typed_pos_args('compiler.preprocess', varargs=(mesonlib.File, str), min_varargs=1)
+    @typed_kwargs(
+        'compiler.preprocess',
+        KwargInfo('output', str, default='@PLAINNAME@.i'),
+        KwargInfo('compile_args', ContainerTypeInfo(list, str), listify=True, default=[]),
+        _INCLUDE_DIRS_KW,
+    )
+    def preprocess_method(self, args: T.Tuple[T.List['mesonlib.FileOrString']], kwargs: 'PreprocessKW') -> T.List[build.CustomTargetIndex]:
+        compiler = self.compiler.get_preprocessor()
+        sources = self.interpreter.source_strings_to_files(args[0])
+        tg_kwargs = {
+            f'{self.compiler.language}_args': kwargs['compile_args'],
+            'build_by_default': False,
+            'include_directories': kwargs['include_directories'],
+        }
+        tg = build.CompileTarget(
+            'preprocessor',
+            self.interpreter.subdir,
+            self.subproject,
+            self.environment,
+            sources,
+            kwargs['output'],
+            compiler,
+            tg_kwargs)
+        self.interpreter.add_target(tg.name, tg)
+        # Expose this target as list of its outputs, so user can pass them to
+        # other targets, list outputs, etc.
+        private_dir = os.path.relpath(self.interpreter.backend.get_target_private_dir(tg), self.interpreter.subdir)
+        return [build.CustomTargetIndex(tg, os.path.join(private_dir, o)) for o in tg.outputs]