1 files changed, 145 insertions, 0 deletions
diff --git a/dom/media/webrtc/third_party_build/extract-for-git.py b/dom/media/webrtc/third_party_build/extract-for-git.py
new file mode 100644
index 0000000000..d2701d7dff
--- /dev/null
+++ b/dom/media/webrtc/third_party_build/extract-for-git.py
@@ -0,0 +1,145 @@
+# 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/.
+import argparse
+import os
+import re
+import subprocess
+
+# This script extracts commits that touch third party webrtc code so they can
+# be imported into Git. It filters out commits that are not part of upstream
+# code and rewrites the paths to match upstream. Finally, the commits are
+# combined into a mailbox file that can be applied with `git am`.
+LIBWEBRTC_DIR = "third_party/libwebrtc"
+
+
+def build_commit_list(revset, env):
+    """Build commit list from the specified revset.
+
+    The revset can be a single revision, e.g. 52bb9bb94661, or a range,
+    e.g. 8c08a5bb8a99::52bb9bb94661, or any other valid revset
+    (check hg help revset). Only commits that touch libwebrtc are included.
+    """
+    res = subprocess.run(
+        ["hg", "log", "-r", revset, "-M", "--template", "{node}\n", LIBWEBRTC_DIR],
+        capture_output=True,
+        text=True,
+        env=env,
+    )
+    return [line.strip() for line in res.stdout.strip().split("\n")]
+
+
+def extract_author_date(sha1, env):
+    res = subprocess.run(
+        ["hg", "log", "-r", sha1, "--template", "{author}|{date|isodate}"],
+        capture_output=True,
+        text=True,
+        env=env,
+    )
+    return res.stdout.split("|")
+
+
+def extract_description(sha1, env):
+    res = subprocess.run(
+        ["hg", "log", "-r", sha1, "--template", "{desc}"],
+        capture_output=True,
+        text=True,
+        env=env,
+    )
+    return res.stdout
+
+
+def extract_commit(sha1, env):
+    res = subprocess.run(
+        ["hg", "log", "-r", sha1, "-pg", "--template", "\n"],
+        capture_output=True,
+        text=True,
+        env=env,
+    )
+    return res.stdout
+
+
+def filter_nonwebrtc(commit):
+    filtered = []
+    skipping = False
+    for line in commit.split("\n"):
+        # Extract only patches affecting libwebrtc, but avoid commits that
+        # touch build, which is tracked by a separate repo, or that affect
+        # moz.build files which are code generated.
+        if (
+            line.startswith("diff --git a/" + LIBWEBRTC_DIR)
+            and not line.startswith("diff --git a/" + LIBWEBRTC_DIR + "/build")
+            and not line.startswith("diff --git a/" + LIBWEBRTC_DIR + "/third_party")
+            and not line.startswith(
+                "diff --git a/" + LIBWEBRTC_DIR + "/moz-patch-stack"
+            )
+            and not line.endswith("moz.build")
+        ):
+            skipping = False
+        elif line.startswith("diff --git"):
+            skipping = True
+
+        if not skipping:
+            filtered.append(line)
+    return "\n".join(filtered)
+
+
+def fixup_paths(commit):
+    # make sure we only rewrite paths in the diff-related or rename lines
+    commit = re.sub(
+        f"^rename (from|to) {LIBWEBRTC_DIR}/", "rename \\1 ", commit, flags=re.MULTILINE
+    )
+    return re.sub(f"( [ab])/{LIBWEBRTC_DIR}/", "\\1/", commit)
+
+
+def write_as_mbox(sha1, author, date, description, commit, ofile):
+    # Use same magic date as git format-patch
+    ofile.write("From {} Mon Sep 17 00:00:00 2001\n".format(sha1))
+    ofile.write("From: {}\n".format(author))
+    ofile.write("Date: {}\n".format(date))
+    description = description.split("\n")
+    ofile.write("Subject: {}\n".format(description[0]))
+    ofile.write("\n".join(description[1:]))
+    ofile.write(
+        "\nMercurial Revision: https://hg.mozilla.org/mozilla-central/rev/{}\n".format(
+            sha1
+        )
+    )
+    ofile.write(commit)
+    ofile.write("\n")
+    ofile.write("\n")
+
+
+if __name__ == "__main__":
+    commits = []
+    parser = argparse.ArgumentParser(
+        description="Format commits for upstream libwebrtc"
+    )
+    parser.add_argument(
+        "revsets", metavar="revset", type=str, nargs="+", help="A revset to process"
+    )
+    parser.add_argument(
+        "--target", choices=("libwebrtc", "build", "third_party"), default="libwebrtc"
+    )
+    args = parser.parse_args()
+
+    if args.target != "libwebrtc":
+        LIBWEBRTC_DIR = os.path.join(LIBWEBRTC_DIR, args.target)
+
+    # must run 'hg' with HGPLAIN=1 to ensure aliases don't interfere with
+    # command output.
+    env = os.environ.copy()
+    env["HGPLAIN"] = "1"
+
+    for revset in args.revsets:
+        commits.extend(build_commit_list(revset, env))
+
+    with open("mailbox.patch", "w") as ofile:
+        for sha1 in commits:
+            author, date = extract_author_date(sha1, env)
+            description = extract_description(sha1, env)
+            filtered_commit = filter_nonwebrtc(extract_commit(sha1, env))
+            if len(filtered_commit) == 0:
+                continue
+            fixedup_commit = fixup_paths(filtered_commit)
+            write_as_mbox(sha1, author, date, description, fixedup_commit, ofile)