rust: clean up inputs and outputs to bindgen

Make the handling of bindgen inputs consistent with the inputs and outputs of
source_strings_to_files.

However, for the first source argument reject anything that cannot
possibly be an header file.  This also fixes a mypy failure from the next
patch, since ExtractedObjects does not have a zero-argument get_outputs
method.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

mesonbuild/modules/unstable_rust.py

@@ -17,7 +17,7 @@ import typing as T
 
 from . import ExtensionModule, ModuleReturnValue
 from .. import mlog
-from ..build import BothLibraries, BuildTarget, CustomTargetIndex, Executable, GeneratedList, IncludeDirs, CustomTarget
+from ..build import BothLibraries, BuildTarget, CustomTargetIndex, Executable, ExtractedObjects, GeneratedList, IncludeDirs, CustomTarget
 from ..dependencies import Dependency, ExternalLibrary
 from ..interpreter.interpreter import TEST_KWARGS
 from ..interpreterbase import ContainerTypeInfo, InterpreterException, KwargInfo, FeatureNew, typed_kwargs, typed_pos_args, noPosargs
@@ -27,7 +27,7 @@ if T.TYPE_CHECKING:
     from . import ModuleState
     from ..interpreter import Interpreter
     from ..interpreter import kwargs as _kwargs
-    from ..interpreter.interpreter import SourceInputs
+    from ..interpreter.interpreter import SourceInputs, SourceOutputs
     from ..programs import ExternalProgram
 
     from typing_extensions import TypedDict
@@ -168,7 +168,7 @@ class RustModule(ExtensionModule):
         KwargInfo('include_directories', ContainerTypeInfo(list, IncludeDirs), default=[], listify=True),
         KwargInfo(
             'input',
-            ContainerTypeInfo(list, (File, GeneratedList, BuildTarget, BothLibraries, CustomTargetIndex, CustomTarget, str), allow_empty=False),
+            ContainerTypeInfo(list, (File, GeneratedList, BuildTarget, BothLibraries, ExtractedObjects, CustomTargetIndex, CustomTarget, str), allow_empty=False),
             default=[],
             listify=True,
             required=True,
@@ -184,7 +184,7 @@ class RustModule(ExtensionModule):
         header, *_deps = self.interpreter.source_strings_to_files(kwargs['input'])
 
         # Split File and Target dependencies to add pass to CustomTarget
-        depends: T.List[T.Union[GeneratedList, BuildTarget, CustomTargetIndex, CustomTarget]] = []
+        depends: T.List['SourceOutputs'] = []
         depend_files: T.List[File] = []
         for d in _deps:
             if isinstance(d, File):
@@ -203,6 +203,8 @@ class RustModule(ExtensionModule):
         name: str
         if isinstance(header, File):
             name = header.fname
+        elif isinstance(header, (BuildTarget, BothLibraries, ExtractedObjects)):
+            raise InterpreterException('bindgen source file must be a C header, not an object or build target')
         else:
             name = header.get_outputs()[0]
 

test cases/failing/115 nonsensical bindgen/meson.build

@@ -0,0 +1,20 @@
+# SPDX-license-identifer: Apache-2.0
+# Copyright © 2021 Intel Corporation
+
+project('rustmod bindgen', 'c')
+
+if not add_languages('rust', required: false)
+  error('MESON_SKIP_TEST test requires rust compiler')
+endif
+
+prog_bindgen = find_program('bindgen', required : false)
+if not prog_bindgen.found()
+  error('MESON_SKIP_TEST bindgen not found')
+endif
+
+c_lib = static_library('clib', 'src/source.c')
+
+import('unstable-rust').bindgen(
+  input : c_lib,
+  output : 'header.rs',
+)

test cases/failing/115 nonsensical bindgen/src/header.h

@@ -0,0 +1,8 @@
+// SPDX-license-identifer: Apache-2.0
+// Copyright © 2021 Intel Corporation
+
+#pragma once
+
+#include <stdint.h>
+
+int32_t add(const int32_t, const int32_t);

test cases/failing/115 nonsensical bindgen/src/source.c

@@ -0,0 +1,8 @@
+// SPDX-license-identifer: Apache-2.0
+// Copyright © 2021 Intel Corporation
+
+#include "header.h"
+
+int32_t add(const int32_t first, const int32_t second) {
+    return first + second;
+}

test cases/failing/115 nonsensical bindgen/test.json

@@ -0,0 +1,8 @@
+{
+    "stdout": [
+        {
+            "line": "test cases/failing/115 nonsensical bindgen/meson.build:17:24: ERROR: bindgen source file must be a C header, not an object or build target"
+        }
+    ]
+}
+