build: allow non-Rust files in non-structured sources

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

3 files changed, 15 insertions, 4 deletions

diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 1780e96e9..52063866b 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -1980,6 +1980,7 @@ class NinjaBackend(backends.Backend):
                                      for s in f.get_outputs()])
             self.all_structured_sources.update(_ods)
             orderdeps.extend(_ods)
+            return orderdeps, main_rust_file
 
         for i in target.get_sources():
             if main_rust_file is None:
diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index 4f581de31..410b4d243 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -771,18 +771,22 @@ class BuildTarget(Target):
         ''' Initialisations and checks requiring the final list of compilers to be known
         '''
         self.validate_sources()
-        if self.structured_sources and any([self.sources, self.generated]):
-            raise MesonException('cannot mix structured sources and unstructured sources')
-        if self.structured_sources and 'rust' not in self.compilers:
-            raise MesonException('structured sources are only supported in Rust targets')
         if self.uses_rust():
             if self.link_language and self.link_language != 'rust':
                 raise MesonException('cannot build Rust sources with a different link_language')
+            if self.structured_sources:
+                # TODO: the interpreter should be able to generate a better error message?
+                if any((s.endswith('.rs') for s in self.sources)) or \
+                       any(any((s.endswith('.rs') for s in g.get_outputs())) for g in self.generated):
+                    raise MesonException('cannot mix Rust structured sources and unstructured sources')
 
             # relocation-model=pic is rustc's default and Meson does not
             # currently have a way to disable PIC.
             self.pic = True
             self.pie = True
+        else:
+            if self.structured_sources:
+                raise MesonException('structured sources are only supported in Rust targets')
 
         if 'vala' in self.compilers and self.is_linkable_target():
             self.outputs += [self.vala_header, self.vala_vapi]
diff --git a/test cases/rust/28 mixed/meson.build b/test cases/rust/28 mixed/meson.build
index b00d8ac88..fac3d466f 100644
--- a/test cases/rust/28 mixed/meson.build
+++ b/test cases/rust/28 mixed/meson.build
@@ -2,5 +2,11 @@
 project('mixed', ['cpp', 'rust'])
 
 e1 = executable('mixed', 'hello.rs', 'main.cc')
+e2 = executable('mixed-structured', structured_sources('hello.rs'), 'main.cc')
+
+hello2 = import('fs').copyfile('hello.rs', 'hello2.rs')
+e3 = executable('mixed-structured-gen', structured_sources(hello2), 'main.cc')
 
 test('mixed', e1)
+test('mixed-structured', e2)
+test('mixed-structured-gen', e3)