Skip parsing test files that don't need regeneration

tools/generation/generator.py

@@ -49,8 +49,8 @@ def create(args):
         for test in exp.expand('utf-8', caseFile):
             if args.out:
                 try:
-                    existing = Test(test.file_name)
-                    existing.load(args.out)
+                    test_file = os.path.join(args.out, test.file_name)
+                    test_mtime = os.path.getmtime(test_file)
 
                     if args.no_clobber:
                         print_error(
@@ -58,18 +58,18 @@ def create(args):
                         exit(1)
 
                     if not args.regenerate:
-                        test_file = os.path.join(args.out, test.file_name)
-                        test_mtime = os.path.getmtime(test_file)
                         source_files = test.source_file_names
                         if all(test_mtime > os.path.getmtime(f) for f in source_files):
                             continue
 
+                    existing = Test(test_file)
+                    existing.load()
                     if not existing.is_generated():
                         print_error(
                             'Refusing to overwrite non-generated file: ' +
                             test.file_name)
                         exit(1)
-                except IOError:
+                except (OSError, IOError):
                     pass
 
                 test.write(args.out, parents=args.parents)

tools/generation/lib/test.py

@@ -24,9 +24,8 @@ class Test:
         self.source = None
         self.attribs = dict(meta=None)
 
-    def load(self, prefix = None):
-        location = os.path.join(prefix or '', self.file_name)
-        with open(location, 'r') as handle:
+    def load(self):
+        with open(self.file_name, 'r') as handle:
             self.source = handle.read()
         self._parse()