profile_diffs.py: script to compare Go coverage profiles, outputs new…

profile_diffs.py

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+import sys
+
+def find_newly_hit_blocks(first_profile_path, second_profile_path, output_path):
+    """
+    Given two paths to Go coverage profiles, determine which basic blocks are hit
+    in the second coverage profile and not the first. This can be used to tell if
+    coverage has increased from the first profile to the second profile.
+    TODO: Compare the # of times that a basic block has been hit as well.
+
+    Args:
+        first_profile_path (str): Path to the first Go coverage profile.
+        second_profile_path (str): Path to the second Go coverage profile.
+        output_path (str): Path to save the new code blocks.
+    """
+    try:
+        # Read the two profiles
+        with open(first_profile_path, 'r') as prof1, open(second_profile_path, 'r') as prof2:
+            prof1_lines = prof1.readlines()
+            prof2_lines = prof2.readlines()
+
+        # Parse lines into sets of code blocks
+        def parse_coverage(lines):
+            coverage = {}
+            for line in lines:
+                # Split on whitespace
+                parts = line.split()
+
+                # The last digit in a coverage profile denotes how many times it was
+                # hit during the profile. Extract this value. The "block" is the part
+                # of the coverage profile _before_ the hit counter.
+                if len(parts) > 0 and parts[-1].isdigit():
+                    block = " ".join(parts[:-1])
+                    hit = int(parts[-1])
+                    coverage[block] = hit
+
+            # Return the coverage map for comparison.
+            return coverage
+
+        file1_coverage = parse_coverage(prof1_lines)
+        file2_coverage = parse_coverage(prof2_lines)
+
+        # Find blocks hit in the second profile but not in the first
+        newly_hit_blocks = []
+        for block, hit in file2_coverage.items():
+            if hit > 0 and file1_coverage.get(block, 0) == 0:
+                newly_hit_blocks.append(f"{block} {hit}\n")
+
+        # Write newly hit blocks to the output file
+        with open(output_path, 'w') as output_file:
+            output_file.writelines(newly_hit_blocks)
+
+        print(f"Newly hit blocks have been extracted and saved to: {output_path}")
+
+    except Exception as e:
+        print(f"An error occurred: {e}")
+
+def main(file1_path, file2_path, output_path):
+    find_newly_hit_blocks(file1_path, file2_path, output_path)
+
+if __name__ == "__main__":
+    if len(sys.argv) != 4:
+        print("Usage: python profile_diffs.py <profile1_path> <profile2_path> <output_path>")
+        sys.exit(1)
+
+    file1_path = sys.argv[1]
+    file2_path = sys.argv[2]
+    output_path = sys.argv[3]
+
+    main(file1_path, file2_path, output_path)