Rust: Add a rust.proc_macro() method

docs/markdown/Rust-module.md

@@ -105,3 +105,32 @@ were never turned on by Meson.
 [properties]
 bindgen_clang_arguments = ['--target', 'x86_64-linux-gnu']
 ```
+
+### proc_macro()
+
+```meson
+rustmod.proc_macro(name, sources, ...)
+```
+
+*Since 1.3.0*
+
+This function creates a Rust `proc-macro` crate, similar to:
+```meson
+[[shared_library]](name, sources,
+  rust_crate_type: 'proc-macro',
+  native: true)
+```
+
+`proc-macro` targets can be passed to `link_with` keyword argument of other Rust
+targets.
+
+Only a subset of [[shared_library]] keyword arguments are allowed:
+- rust_args
+- rust_dependency_map
+- sources
+- dependencies
+- extra_files
+- link_args
+- link_depends
+- link_with
+- override_options

mesonbuild/modules/rust.py

@@ -15,13 +15,15 @@ from __future__ import annotations
 
 import os
 import typing as T
+from mesonbuild.interpreterbase.decorators import FeatureNew
 
 from . import ExtensionModule, ModuleReturnValue, ModuleInfo
 from .. import mlog
-from ..build import BothLibraries, BuildTarget, CustomTargetIndex, Executable, ExtractedObjects, GeneratedList, CustomTarget, InvalidArguments, Jar, StructuredSources
+from ..build import (BothLibraries, BuildTarget, CustomTargetIndex, Executable, ExtractedObjects, GeneratedList,
+                     CustomTarget, InvalidArguments, Jar, StructuredSources, SharedLibrary)
 from ..compilers.compilers import are_asserts_disabled
-from ..interpreter.type_checking import DEPENDENCIES_KW, LINK_WITH_KW, TEST_KWS, OUTPUT_KW, INCLUDE_DIRECTORIES
-from ..interpreterbase import ContainerTypeInfo, InterpreterException, KwargInfo, typed_kwargs, typed_pos_args, noPosargs
+from ..interpreter.type_checking import DEPENDENCIES_KW, LINK_WITH_KW, SHARED_LIB_KWS, TEST_KWS, OUTPUT_KW, INCLUDE_DIRECTORIES, SOURCES_VARARGS
+from ..interpreterbase import ContainerTypeInfo, InterpreterException, KwargInfo, typed_kwargs, typed_pos_args, noPosargs, permittedKwargs
 from ..mesonlib import File
 
 if T.TYPE_CHECKING:
@@ -32,6 +34,7 @@ if T.TYPE_CHECKING:
     from ..interpreter import kwargs as _kwargs
     from ..interpreter.interpreter import SourceInputs, SourceOutputs
     from ..programs import ExternalProgram, OverrideProgram
+    from ..interpreter.type_checking import SourcesVarargsType
 
     from typing_extensions import TypedDict
 
@@ -64,6 +67,7 @@ class RustModule(ExtensionModule):
         self.methods.update({
             'test': self.test,
             'bindgen': self.bindgen,
+            'proc_macro': self.proc_macro,
         })
 
     @typed_pos_args('rust.test', str, BuildTarget)
@@ -268,6 +272,19 @@ class RustModule(ExtensionModule):
 
         return ModuleReturnValue([target], [target])
 
+    # Allow a limited set of kwargs, but still use the full set of typed_kwargs()
+    # because it could be setting required default values.
+    @FeatureNew('rust.proc_macro', '1.3.0')
+    @permittedKwargs({'rust_args', 'rust_dependency_map', 'sources', 'dependencies', 'extra_files',
+                      'link_args', 'link_depends', 'link_with', 'override_options'})
+    @typed_pos_args('rust.proc_macro', str, varargs=SOURCES_VARARGS)
+    @typed_kwargs('rust.proc_macro', *SHARED_LIB_KWS, allow_unknown=True)
+    def proc_macro(self, state: ModuleState, args: T.Tuple[str, SourcesVarargsType], kwargs: T.Dict) -> SharedLibrary:
+        kwargs['native'] = True
+        kwargs['rust_crate_type'] = 'proc-macro'
+        target = state._interpreter.build_target(state.current_node, args, kwargs, SharedLibrary)
+        return T.cast('SharedLibrary', target)
+
 
 def initialize(interp: Interpreter) -> RustModule:
     return RustModule(interp)

test cases/rust/18 proc-macro/meson.build

@@ -18,3 +18,16 @@ main = executable(
 )
 
 test('main_test', main)
+
+rust = import('rust')
+
+pm = rust.proc_macro('proc_macro_examples2', 'proc.rs')
+
+main = executable(
+  'main2',
+  'use.rs',
+  link_with : pm,
+  rust_dependency_map : {'proc_macro_examples2' : 'proc_macro_examples'}
+)
+
+test('main_test2', main)