untracked-allocations.py

#!/usr/bin/env python3

# Copyright 2025 The Servo Project Developers. See the COPYRIGHT
# file at the top-level directory of this distribution.
#
# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
# option. This file may not be copied, modified, or distributed
# except according to those terms.

# usage: python3 untracked-allocations.py [file] [crate-name] [max stacks]

import operator
import sys

with open(sys.argv[1]) as f:
    lines = f.readlines()

crates = {}
skippable_prefixes = [
    "/Users/jdm/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/",
    "/Users/jdm/.cargo/git/checkouts/",
    "/Users/jdm/.rustup/toolchains/1.85.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/",
    "/Users/jdm/.rustup/toolchains/1.89.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/",
    "/Users/jdm/src/servo/target/debug/build/",
    "/Users/jdm/src/alt-servo/target/debug/build/",
    "/rustc/4d91de4e48198da2e33413efdcd9cd2cc0c46688/library/",
    "/rustc/29483883eed69d5fb4db01964cdf2af4d86e9cb2/library/",
    "/rust/deps/",
    "???:0",
    "/Users/jdm/src/servo/components/shared/",
    "/Users/jdm/src/servo/components/",
    "/Users/jdm/src/servo/ports/",
    "/Users/jdm/src/alt-servo/components/shared/",
    "/Users/jdm/src/alt-servo/components/",
    "/Users/jdm/src/alt-servo/ports/",
]
skippable_crates = [
    "thin-vec-0.2.14",
    "alloc",
    "core",
    "std",
    "bytes-1.10.1",
    "servo_arc",
    "smallvec-1.15.1",
    "hashbrown-0.15.2",
    "hashbrown-0.15.5",
    "indexmap-2.10.0",
    "slotmap-1.0.7",
    "smallbitvec-2.6.0",
]
entries = []
current = None
for line in lines:
    line = line.strip()
    if line == "---":
        if current:
            if not current["highlight"]:
                current["highlight"] = {"crate": "", "filename": "", "method": ""}
            entries += [current]
        current = {
            "size": 0,
            "highlight": None,
            "frames": [],
        }
        continue

    if line.isdigit():
        current["size"] = int(line)
        continue

    if not line:
        continue

    current["frames"] += [line]

    if not current["highlight"]:
        # print(line)
        (path, method) = line.split(" ", maxsplit=1)
        original_path = path
        # print(path)
        for prefix in skippable_prefixes:
            path = path.removeprefix(prefix)
        if not path:
            continue

        # print(path)
        crate = path.split("/")[0]
        if not crate:
            print(original_path)
            raise "oops"
        # print(crate)
        if crate in skippable_crates:
            continue
        method = "::".join(method[1:-1].split("::")[:-1])
        filename = "/".join(path.split("/")[1:]).split(":")[0]
        current["highlight"] = {"crate": crate, "method": method, "filename": filename}
        if crate not in crates:
            crates[crate] = 0
        crates[crate] += 1

print("Overall stats")
for crate in sorted(crates, key=lambda x: crates[x], reverse=True):
    print(f"{crate}: {crates[crate]}")

if len(sys.argv) > 2:
    print()
    relevant = filter(lambda entry: entry["highlight"]["crate"] == sys.argv[2], entries)
    count = 0
    limit = int(sys.argv[3]) if len(sys.argv) > 3 else 10
    for entry in sorted(relevant, key=lambda x: x["size"], reverse=True):
        if count == limit:
            break
        print(f"{entry['size']} - {entry['highlight']['method']}")
        count += 1