[NFC][lit] Cleanup code using string interpolation

LLVM now requires Python 3.6, so we can use string interpolation to make
code more readable.

Author: Julian Lettner

llvm/utils/lit/lit/main.py

@@ -179,14 +179,12 @@ def filter_by_shard(tests, run, shards, lit_config):
     # For clarity, generate a preview of the first few test indices in the shard
     # to accompany the arithmetic expression.
     preview_len = 3
-    preview = ", ".join([str(i + 1) for i in test_ixs[:preview_len]])
+    preview = ', '.join([str(i + 1) for i in test_ixs[:preview_len]])
     if len(test_ixs) > preview_len:
-        preview += ", ..."
-    # TODO(python3): string interpolation
-    msg = 'Selecting shard {run}/{shards} = size {sel_tests}/{total_tests} = ' \
-          'tests #({shards}*k)+{run} = [{preview}]'.format(
-              run=run, shards=shards, sel_tests=len(selected_tests),
-              total_tests=len(tests), preview=preview)
+        preview += ', ...'
+    msg = f'Selecting shard {run}/{shards} = ' \
+          f'size {len(selected_tests)}/{len(tests)} = ' \
+          f'tests #({shards}*k)+{run} = [{preview}]'
     lit_config.note(msg)
     return selected_tests
 

llvm/utils/lit/lit/reports.py

@@ -104,22 +104,17 @@ def _write_testsuite(self, file, suite, tests):
         failures = sum(1 for t in tests if t.isFailure())
 
         name = suite.config.name.replace('.', '-')
-        # file.write(f'<testsuite name={quo(name)} tests="{len(tests)}" failures="{failures}" skipped="{skipped}">\n')
-        file.write('<testsuite name={name} tests="{tests}" failures="{failures}" skipped="{skipped}">\n'.format(
-            name=quo(name), tests=len(tests), failures=failures, skipped=skipped))
+        file.write(f'<testsuite name={quo(name)} tests="{len(tests)}" failures="{failures}" skipped="{skipped}">\n')
         for test in tests:
             self._write_test(file, test, name)
         file.write('</testsuite>\n')
 
     def _write_test(self, file, test, suite_name):
         path = '/'.join(test.path_in_suite[:-1]).replace('.', '_')
-        # class_name = f'{suite_name}.{path or suite_name}'
-        class_name = suite_name + '.' + (path or suite_name)
+        class_name = f'{suite_name}.{path or suite_name}'
         name = test.path_in_suite[-1]
         time = test.result.elapsed or 0.0
-        # file.write(f'<testcase classname={quo(class_name)} name={quo(name)} time="{time:.2f}"')
-        file.write('<testcase classname={class_name} name={name} time="{time:.2f}"'.format(
-            class_name=quo(class_name), name=quo(name), time=time))
+        file.write(f'<testcase classname={quo(class_name)} name={quo(name)} time="{time:.2f}"')
 
         if test.isFailure():
             file.write('>\n  <failure><![CDATA[')
@@ -140,9 +135,7 @@ def _write_test(self, file, test, suite_name):
             file.write(']]></failure>\n</testcase>\n')
         elif test.result.code in self.skipped_codes:
             reason = self._get_skip_reason(test)
-            # file.write(f'>\n  <skipped message={quo(reason)}/>\n</testcase>\n')
-            file.write('>\n  <skipped message={reason}/>\n</testcase>\n'.format(
-                reason=quo(reason)))
+            file.write(f'>\n  <skipped message={quo(reason)}/>\n</testcase>\n')
         else:
             file.write('/>\n')