feat(tools): add a script for printing Rust stacks' sizes

[no changelog]

.github/workflows/core.yml

@@ -84,6 +84,7 @@ jobs:
       - run: nix-shell --run "poetry run make -C core build_prodtest"
         if: matrix.coins == 'universal' && matrix.type != 'debuglink'
       - run: nix-shell --run "poetry run make -C core build_firmware"
+      - run: nix-shell --run "poetry run ./tools/print-rust-stack-sizes.py | sort -k1 -n | tail -n 50"
       - run: nix-shell --run "poetry run make -C core sizecheck"
         if: matrix.coins == 'universal' && matrix.type != 'debuglink'
       - run: nix-shell --run "poetry run ./tools/check-bitcoin-only core/build/firmware/firmware.bin"

poetry.lock

@@ -1163,6 +1163,17 @@ files = [
     {file = "pycparser-2.21.tar.gz", hash = "sha256:e644fdec12f7872f86c58ff790da456218b10f863970249516d60a5eaca77206"},
 ]
 
+[[package]]
+name = "pyelftools"
+version = "0.32"
+description = "Library for analyzing ELF files and DWARF debugging information"
+optional = false
+python-versions = "*"
+files = [
+    {file = "pyelftools-0.32-py3-none-any.whl", hash = "sha256:013df952a006db5e138b1edf6d8a68ecc50630adbd0d83a2d41e7f846163d738"},
+    {file = "pyelftools-0.32.tar.gz", hash = "sha256:6de90ee7b8263e740c8715a925382d4099b354f29ac48ea40d840cf7aa14ace5"},
+]
+
 [[package]]
 name = "pyflakes"
 version = "3.2.0"
@@ -1905,4 +1916,4 @@ test = ["big-O", "jaraco.functools", "jaraco.itertools", "jaraco.test", "more-it
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.9"
-content-hash = "dc9c84386e9b6cf621114845c095bba59d9a5cc169b1622208de2b270d71cbb8"
+content-hash = "1257cb4cd905c3a00c46535ffa5767cf7bc5af0ac33b80f0adbd5776a8c49d31"

pyproject.toml

@@ -76,6 +76,7 @@ toiftool = {path = "./python/tools/toiftool", develop = true, python = ">=3.8"}
 trezor-pylint-plugin = {path = "./tools/trezor-pylint-plugin", develop = true}
 trezor-core-tools = {path = "./core/tools", develop = true}
 flake8-annotations = "^3.1.1"
+pyelftools = "^0.32"
 
 [tool.poetry.dev-dependencies]
 scan-build = "*"

tools/print-rust-stack-sizes.py

@@ -0,0 +1,58 @@
+#!/usr/bin/env python3
+
+import subprocess
+from pathlib import Path
+
+import click
+
+from elftools.construct import Struct, ULInt32, GreedyRange
+from elftools.common.construct_utils import ULEB128
+from elftools.elf.elffile import ELFFile
+
+SYMBOL_TYPES = ("t", "w")  # text, weak
+
+ROOT = Path(__file__).parent.parent.resolve()
+
+FIRMWARE_ELF = ROOT / "core" / "build" / "firmware" / "firmware.elf"
+elf = ELFFile(FIRMWARE_ELF.open("rb"))
+
+
+def load_address_map():
+    """Load address map from firmware ELF file using `nm`."""
+    out = subprocess.check_output(
+        args=["arm-none-eabi-nm", "--radix=d", "--demangle", FIRMWARE_ELF]
+    )
+    symbols = (line.decode().split(maxsplit=2) for line in out.splitlines())
+    return {
+        int(addr): name for addr, type, name in symbols if type.lower() in SYMBOL_TYPES
+    }
+
+
+def load_stack_sizes():
+    """Load Rust stack sizes from firmware ELF section generated by `-Z emit-stack-sizes`."""
+    stack_sizes = elf.get_section_by_name(".stack_sizes")
+
+    Entries = GreedyRange(
+        Struct(
+            "Entry",
+            ULInt32("symbol_addr"),
+            ULEB128("stack_size"),
+        )
+    )
+    return Entries.parse(stack_sizes.data())
+
+
+@click.command()
+def main():
+    """Print Rust functions' stack size.
+
+    See https://blog.japaric.io/stack-analysis/ for more details.
+    """
+    address_map = load_address_map()
+    for entry in load_stack_sizes():
+        symbol_name = address_map[entry.symbol_addr]
+        print(f"{entry.stack_size}\t{symbol_name}")
+
+
+if __name__ == "__main__":
+    main()