1 files changed, 129 insertions, 0 deletions
diff --git a/js/src/devtools/rootAnalysis/explain.py b/js/src/devtools/rootAnalysis/explain.py
new file mode 100755
index 0000000000..993725273c
--- /dev/null
+++ b/js/src/devtools/rootAnalysis/explain.py
@@ -0,0 +1,129 @@
+#!/usr/bin/python3
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+from __future__ import print_function
+
+import argparse
+import re
+
+from collections import defaultdict
+
+parser = argparse.ArgumentParser(description="Process some integers.")
+parser.add_argument("rootingHazards", nargs="?", default="rootingHazards.txt")
+parser.add_argument("gcFunctions", nargs="?", default="gcFunctions.txt")
+parser.add_argument("hazards", nargs="?", default="hazards.txt")
+parser.add_argument("extra", nargs="?", default="unnecessary.txt")
+parser.add_argument("refs", nargs="?", default="refs.txt")
+args = parser.parse_args()
+
+num_hazards = 0
+num_refs = 0
+num_missing = 0
+
+try:
+    with open(args.rootingHazards) as rootingHazards, open(
+        args.hazards, "w"
+    ) as hazards, open(args.extra, "w") as extra, open(args.refs, "w") as refs:
+        current_gcFunction = None
+
+        # Map from a GC function name to the list of hazards resulting from
+        # that GC function
+        hazardousGCFunctions = defaultdict(list)
+
+        # List of tuples (gcFunction, index of hazard) used to maintain the
+        # ordering of the hazards
+        hazardOrder = []
+
+        # Map from a hazardous GC function to the filename containing it.
+        fileOfFunction = {}
+
+        for line in rootingHazards:
+            m = re.match(r"^Time: (.*)", line)
+            mm = re.match(r"^Run on:", line)
+            if m or mm:
+                print(line, file=hazards)
+                print(line, file=extra)
+                print(line, file=refs)
+                continue
+
+            m = re.match(r"^Function.*has unnecessary root", line)
+            if m:
+                print(line, file=extra)
+                continue
+
+            m = re.match(r"^Function.*takes unsafe address of unrooted", line)
+            if m:
+                num_refs += 1
+                print(line, file=refs)
+                continue
+
+            m = re.match(
+                r"^Function.*has unrooted.*of type.*live across GC call '(.*?)' at (\S+):\d+$",
+                line,
+            )  # NOQA: E501
+            if m:
+                current_gcFunction = m.group(1)
+                hazardousGCFunctions[current_gcFunction].append(line)
+                hazardOrder.append(
+                    (
+                        current_gcFunction,
+                        len(hazardousGCFunctions[current_gcFunction]) - 1,
+                    )
+                )
+                num_hazards += 1
+                fileOfFunction[current_gcFunction] = m.group(2)
+                continue
+
+            m = re.match(r"Function.*expected hazard.*but none were found", line)
+            if m:
+                num_missing += 1
+                print(line + "\n", file=hazards)
+                continue
+
+            if current_gcFunction:
+                if not line.strip():
+                    # Blank line => end of this hazard
+                    current_gcFunction = None
+                else:
+                    hazardousGCFunctions[current_gcFunction][-1] += line
+
+        with open(args.gcFunctions) as gcFunctions:
+            gcExplanations = {}  # gcFunction => stack showing why it can GC
+
+            current_func = None
+            explanation = None
+            for line in gcFunctions:
+                m = re.match(r"^GC Function: (.*)", line)
+                if m:
+                    if current_func:
+                        gcExplanations[current_func] = explanation
+                    current_func = None
+                    if m.group(1) in hazardousGCFunctions:
+                        current_func = m.group(1)
+                        explanation = line
+                elif current_func:
+                    explanation += line
+            if current_func:
+                gcExplanations[current_func] = explanation
+
+        for gcFunction, index in hazardOrder:
+            gcHazards = hazardousGCFunctions[gcFunction]
+
+            if gcFunction in gcExplanations:
+                print(gcHazards[index] + gcExplanations[gcFunction], file=hazards)
+            else:
+                print(gcHazards[index], file=hazards)
+
+except IOError as e:
+    print("Failed: %s" % str(e))
+
+print("Wrote %s" % args.hazards)
+print("Wrote %s" % args.extra)
+print("Wrote %s" % args.refs)
+print(
+    "Found %d hazards %d unsafe references %d missing"
+    % (num_hazards, num_refs, num_missing)
+)