Add time summary at the end of the build

Author: shahmishal

utils/build-script

@@ -40,6 +40,7 @@ from swift_build_support.swift_build_support.toolchain import host_toolchain
 from swift_build_support.swift_build_support.utils \
     import exit_rejecting_arguments
 from swift_build_support.swift_build_support.utils import fatal_error
+from swift_build_support.swift_build_support.utils import log_analyzer
 
 
 # -----------------------------------------------------------------------------
@@ -719,6 +720,9 @@ def main():
 
 if __name__ == "__main__":
     try:
-        sys.exit(main())
+        exit_code = main()
     except KeyboardInterrupt:
         sys.exit(1)
+    finally:
+        log_analyzer()
+    sys.exit(exit_code)

utils/swift_build_support/swift_build_support/utils.py

@@ -55,3 +55,37 @@ def log_time(event, command, duration=0):
 
     f.write("{}\n".format(json.dumps(log_event)))
     f.close()
+
+
+def log_analyzer():
+    """
+    Analyze .build_script_log and provide a summary of the time execution.
+    """
+    build_script_log_path = log_time_path()
+    print("--- Build Script Analyzer ---")
+    build_events = []
+    total_duration = 0
+    if os.path.exists(build_script_log_path):
+        print("Build Script Log: {}".format(build_script_log_path))
+        with open(build_script_log_path) as f:
+            for event in f:
+                build_event = json.loads(event)
+                build_event["duration"] = float(build_event["duration"])
+                total_duration += build_event["duration"]
+                build_events.append(build_event)
+        finish_events = [x for x in build_events if x["event"] == "end"]
+        finish_events.sort(key=lambda x: x["duration"], reverse=True)
+
+        print("Build Percentage \t Build Duration (sec) \t Build Phase")
+        print("================ \t ==================== \t ===========")
+        event_row = '{:<17.1%} \t {:<21} \t {}'
+        for build_event in finish_events:
+            duration_percentage = \
+                (float(build_event["duration"]) / float(total_duration))
+            print(event_row.format(duration_percentage,
+                                   build_event["duration"],
+                                   build_event["command"]))
+        print("Total Duration: {}".format(total_duration))
+    else:
+        print("Skip build script analyzer")
+        print(".build_script_log file not found at {}".format(build_script_log_path))