Make it possible to only do unity builds on subprojects.

1 files changed, 8 insertions, 1 deletions

diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py
index a77047b..6a00d17 100644
--- a/mesonbuild/backend/backends.py
+++ b/mesonbuild/backend/backends.py
@@ -306,7 +306,7 @@ class Backend:
         # With unity builds, there's just one object that contains all the
         # sources, and we only support extracting all the objects in this mode,
         # so just return that.
-        if self.get_option_for_target('unity', target):
+        if self.is_unity(target):
             comp = get_compiler_for_source(extobj.target.compilers.values(),
                                            extobj.srclist[0])
             # There is a potential conflict here, but it is unlikely that
@@ -607,6 +607,13 @@ class Backend:
                     libs.append(os.path.join(self.get_target_dir(t), f))
         return libs
 
+    def is_unity(self, target):
+        optval = self.get_option_for_target('unity', target)
+        if optval == 'on' or (optval == 'subprojects' and target.subproject != ''):
+            return True
+        return False
+
+
     def get_custom_target_sources(self, target):
         '''
         Custom target sources can be of various object types; strings, File,