Add script to merge multiple -ftime-trace outputs.

Author: ktf

scripts/profile-compilation-merge

@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+ 
+"""Combine JSON from multiple -ftime-traces into one.
+ 
+scripts/profile-compilation-merge foo.json bar.json.
+
+results in ./combined.json
+"""
+ 
+import json
+import sys
+ 
+if __name__ == '__main__':
+    start_time = 0
+    combined_data = []
+    for filename in sys.argv[1:]:
+        with open(filename, 'r') as f:
+            file_time = None
+            for event in json.load(f)['traceEvents']:
+                # Skip metadata events
+                # Skip total events
+               # Filter out shorter events to reduce data size
+               if event['ph'] == 'M' or \
+                    event['name'].startswith('Total') or \
+                    event['dur'] < 5000:
+                    continue
+ 
+               if event['name'] == 'ExecuteCompiler':
+                    # Find how long this compilation takes
+                    file_time = event['dur']
+                    # Set the file name in ExecuteCompiler
+                    #event['args']['detail'] = filename
+ 
+               # Offset start time to make compiles sequential
+               event['ts'] += start_time
+ 
+               # Add data to combined
+               combined_data.append(event)
+ 
+            # Increase the start time for the next file
+            # Add 1 to avoid issues with simultaneous events
+            start_time += file_time + 1
+ 
+    with open('combined.json', 'w') as f:
+        json.dump({'traceEvents': sorted(combined_data, key=lambda k: k['ts'])}, f)