take override_option('unity=...') into account when allowing extract_objects()

A single target could be picked for unity build, and in that case
extract_objects() should not be allowed.

Likewise for the opposite case, where extract_objects() should be allowed
if unity build is disabled for a single target.  A test that covers that
case is added later.

1 files changed, 1 insertions, 5 deletions

diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py
index 8524bf9..fb4163f 100644
--- a/mesonbuild/backend/backends.py
+++ b/mesonbuild/backend/backends.py
@@ -836,7 +836,7 @@ class Backend:
         # With unity builds, sources don't map directly to objects,
         # we only support extracting all the objects in this mode,
         # so just return all object files.
-        if self.is_unity(extobj.target):
+        if extobj.target.is_unity:
             compsrcs = classify_unity_sources(extobj.target.compilers.values(), sources)
             sources = []
             unity_size = extobj.target.get_option(OptionKey('unity_size'))
@@ -1280,10 +1280,6 @@ class Backend:
             libs.extend(self.get_custom_target_provided_by_generated_source(t))
         return libs
 
-    def is_unity(self, target: build.BuildTarget) -> bool:
-        optval = target.get_option(OptionKey('unity'))
-        return optval == 'on' or (optval == 'subprojects' and target.subproject != '')
-
     def get_custom_target_sources(self, target: build.CustomTarget) -> T.List[str]:
         '''
         Custom target sources can be of various object types; strings, File,