modules: rust: add package.executable

Signed-off-by: Paolo Bonzini <[email protected]>

Author: bonzini

docs/markdown/Rust-module.md

@@ -242,12 +242,7 @@ Example usage:
 rust = import('rust')
 cargo = rust.workspace()
 pkg = cargo.package()
-
-executable('my_app', 'src/main.rs',
-  dependencies: pkg.dependencies(),
-  rust_args: pkg.rust_args(),
-  rust_dependency_map: pkg.rust_dependency_map(),
-)
+pkg.executable(install: true)
 ```
 
 ### workspace.subproject()
@@ -379,6 +374,26 @@ Builds a proc-macro crate for a workspace package.
 
 Accepts all keyword arguments from [[shared_library]].
 
+#### package.executable()
+
+```meson
+exe = pkg.executable([target_name], [sources], ...)
+```
+
+Builds an executable target for a workspace package.  The method requires that the
+package has at least one `[[bin]]` section defined in its `Cargo.toml` file,
+or one binary discovered from the contents of the file system.
+
+Positional arguments:
+- `target_name`: (`str`, optional) Name of the binary target to build. If the package
+  has multiple `[[bin]]` sections in `Cargo.toml`, this argument is required and must
+  match one of the binary names. If omitted and there's only one binary, that binary
+  will be built automatically.
+- `sources`: (`StructuredSources`, optional) Source files for the executable.  If omitted,
+  uses the path specified in the corresponding `[[bin]]` section of `Cargo.toml`.
+
+Accepts all keyword arguments from [[executable]].
+
 ### Subprojects only
 
 #### subproject.dependency()

mesonbuild/modules/rust.py

@@ -20,7 +20,7 @@
 from ..interpreter.type_checking import (
     DEPENDENCIES_KW, LINK_WITH_KW, LINK_WHOLE_KW, SHARED_LIB_KWS, TEST_KWS, TEST_KWS_NO_ARGS,
     OUTPUT_KW, INCLUDE_DIRECTORIES, SOURCES_VARARGS, NoneType, in_set_validator,
-    LIBRARY_KWS, _BASE_LANG_KW
+    EXECUTABLE_KWS, LIBRARY_KWS, _BASE_LANG_KW
 )
 from ..interpreterbase import ContainerTypeInfo, InterpreterException, KwargInfo, typed_kwargs, typed_pos_args, noKwargs, noPosargs, permittedKwargs
 from ..interpreter.interpreterobjects import Doctest
@@ -77,6 +77,11 @@ class FuncWorkspace(TypedDict):
     class FuncDependency(TypedDict):
         rust_abi: T.Optional[RUST_ABI]
 
+    class RustPackageExecutable(_kwargs.Executable):
+        dependencies: T.List[T.Union[Dependency, ExternalLibrary]]
+        link_with: T.List[LibTypes]
+        link_whole: T.List[LibTypes]
+
     class RustPackageLibrary(_kwargs.Library):
         dependencies: T.List[T.Union[Dependency, ExternalLibrary]]
         link_with: T.List[LibTypes]
@@ -243,6 +248,7 @@ def __init__(self, rust_ws: RustWorkspace, package: cargo.PackageState) -> None:
             'dependencies': self.dependencies_method,
             'library': self.library_method,
             'proc_macro': self.proc_macro_method,
+            'executable': self.executable_method,
         })
 
     @noPosargs
@@ -290,7 +296,7 @@ def validate_pos_args(name: str, args: T.Tuple[
             raise MesonException(f"{name} only accepts one StructuredSources parameter")
         return None, args[0]
 
-    def merge_kw_args(self, state: ModuleState, kwargs: RustPackageLibrary) -> None:
+    def merge_kw_args(self, state: ModuleState, kwargs: T.Union[RustPackageExecutable, RustPackageLibrary]) -> None:
         deps = kwargs['dependencies']
         kwargs['dependencies'] = self.dependencies_method(state, [], {})
         kwargs['dependencies'].extend(deps)
@@ -382,6 +388,42 @@ def proc_macro_method(self, state: 'ModuleState', args: T.Tuple[
         result = self._library_method(state, args, kwargs)
         return T.cast('SharedLibrary', result)
 
+    @typed_pos_args('package.executable', optargs=[(str, StructuredSources), StructuredSources])
+    @typed_kwargs(
+        'package.executable',
+        *EXECUTABLE_KWS,
+        DEPENDENCIES_KW,
+        LINK_WITH_KW,
+        LINK_WHOLE_KW,
+        _BASE_LANG_KW.evolve(name='rust_args'),
+    )
+    def executable_method(self, state: 'ModuleState', args: T.Tuple[
+            T.Optional[T.Union[str, StructuredSources]],
+            T.Optional[StructuredSources]], kwargs: RustPackageExecutable) -> Executable:
+        """Builds executable targets from workspace bins."""
+        tgt_args = self.validate_pos_args('package.executable', args)
+        if not self.package.manifest.bin:
+            raise MesonException("no [[bin]] section in Cargo package")
+
+        # If there's more than one binary, the first argument must be specified
+        # and must be one of the keys in pkg.bin
+        tgt_name, sources = tgt_args
+        if not tgt_name:
+            if len(self.package.manifest.bin) > 1:
+                raise MesonException("Package has multiple binaries, you must specify which one to build as the first argument")
+            # Single binary, use it
+            tgt_name = next(iter(self.package.manifest.bin.keys()))
+        else:
+            if tgt_name not in self.package.manifest.bin:
+                raise MesonException(f"Binary '{tgt_name}' not found.")
+
+        if not sources:
+            sources = self.package.manifest.bin[tgt_name].path
+
+        exe_args: T.Tuple[str, SourcesVarargsType] = (tgt_name, [sources])
+        self.merge_kw_args(state, kwargs)
+        return state._interpreter.build_target(state.current_node, exe_args, kwargs, Executable)
+
 
 class RustSubproject(RustCrate):
     """Represents a Cargo subproject."""