extract_all_sources: Also include generated object files

Closes #4281.

mesonbuild/backend/backends.py

@@ -443,7 +443,13 @@ class Backend:
                 sources.append(File(True, dirpart, fnamepart))
 
         # Filter out headers and all non-source files
-        sources = [s for s in sources if self.environment.is_source(s) and not self.environment.is_header(s)]
+        filtered_sources = []
+        for s in sources:
+            if self.environment.is_source(s) and not self.environment.is_header(s):
+                filtered_sources.append(s)
+            elif self.environment.is_object(s):
+                result.append(s.relative_name())
+        sources = filtered_sources
 
         # extobj could contain only objects and no sources
         if not sources:

test cases/nasm/1 configure file/meson.build

@@ -47,3 +47,9 @@ exe = executable('hello', asm_gen.process('hello.asm'),
 )
 
 test('test-nasm-configure-file', exe)
+
+exe2 = executable('hello2', objects : exe.extract_all_objects(),
+  link_args: link_args,
+)
+
+test('test-nasm-extract-all-objects', exe2)