[ci/scripts] Add run nm scripts

Prints useful tables about binary size.

TODO: expand it to parse linker map and also dump module, objects, and
section names with a given symbol.

Author: digantdesai

.github/scripts/run_nm.py

@@ -0,0 +1,166 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+import re
+import subprocess
+import sys
+from dataclasses import dataclass
+from typing import Dict, List, Optional, Union
+
+
+@dataclass
+class Symbol:
+    name: str
+    addr: int
+    size: int
+    symbol_type: str
+
+
+class Parser:
+    def __init__(self, elf: str, toolchain_prefix: str = "", filter=None):
+        self.elf = elf
+        self.toolchain_prefix = toolchain_prefix
+        self.symbols: Dict[str, Symbol] = self._get_nm_output()
+        self.filter = filter
+
+    @staticmethod
+    def run_nm(
+        elf_file_path: str, args: Optional[List[str]] = None, nm: str = "nm"
+    ) -> str:
+        """
+        Run the nm command on the specified ELF file.
+        """
+        args = [] if args is None else args
+        cmd = [nm] + args + [elf_file_path]
+        try:
+            result = subprocess.run(cmd, check=True, capture_output=True, text=True)
+            return result.stdout
+        except FileNotFoundError:
+            print(f"Error: 'nm' command not found. Please ensure it's installed.")
+            sys.exit(1)
+        except subprocess.CalledProcessError as e:
+            print(f"Error running nm on {elf_file_path}: {e}")
+            print(f"stderr: {e.stderr}")
+            sys.exit(1)
+
+    def _get_nm_output(self) -> Dict[str, Symbol]:
+        args = [
+            "--print-size",
+            "--size-sort",
+            "--reverse-sort",
+            "--demangle",
+            "--format=bsd",
+        ]
+        output = Parser.run_nm(
+            self.elf,
+            args,
+            nm=self.toolchain_prefix + "nm" if self.toolchain_prefix else "nm",
+        )
+        lines = output.splitlines()
+        symbols = []
+        symbol_pattern = re.compile(
+            r"(?P<addr>[0-9a-fA-F]+)\s+(?P<size>[0-9a-fA-F]+)\s+(?P<type>\w)\s+(?P<name>.+)"
+        )
+
+        def parse_line(line: str) -> Optional[Symbol]:
+
+            match = symbol_pattern.match(line)
+            if match:
+                addr = int(match.group("addr"), 16)
+                size = int(match.group("size"), 16)
+                type_ = match.group("type").strip().strip("\n")
+                name = match.group("name").strip().strip("\n")
+                return Symbol(name=name, addr=addr, size=size, symbol_type=type_)
+            return None
+
+        for line in lines:
+            symbol = parse_line(line)
+            if symbol:
+                symbols.append(symbol)
+
+        assert len(symbols) > 0, "No symbols found in nm output"
+        if len(symbols) != len(lines):
+            print(
+                "** Warning: Not all lines were parsed, check the output of nm. Parsed {len(symbols)} lines, given {len(lines)}"
+            )
+        if any(symbol.size == 0 for symbol in symbols):
+            print("** Warning: Some symbols have zero size, check the output of nm.")
+
+        # TODO: Populate the section and module fields from the linker map if available (-Wl,-Map=linker.map)
+        return {symbol.name: symbol for symbol in symbols}
+
+    def print(self):
+        print(f"Elf: {self.elf}")
+
+        def print_table(filter=None, filter_name=None):
+            print("\nAddress\t\tSize\tType\tName")
+            # Apply filter and sort symbols
+            symbols_to_print = {
+                name: sym
+                for name, sym in self.symbols.items()
+                if not filter or filter(sym)
+            }
+            sorted_symbols = sorted(
+                symbols_to_print.items(), key=lambda x: x[1].size, reverse=True
+            )
+
+            # Print symbols and calculate total size
+            size_total = 0
+            for name, sym in sorted_symbols:
+                print(f"{hex(sym.addr)}\t\t{sym.size}\t{sym.symbol_type}\t{sym.name}")
+                size_total += sym.size
+
+            # Print summary
+            symbol_percent = len(symbols_to_print) / len(self.symbols) * 100
+            print("-----")
+            print(f"> Total bytes: {size_total}")
+            print(
+                f"Counted: {len(symbols_to_print)}/{len(self.symbols)}, {symbol_percent:0.2f}% (filter: '{filter_name}')"
+            )
+            print("=====\n")
+
+        # Print tables with different filters
+        def is_executorch_symbol(s):
+            return "executorch" in s.name or s.name.startswith("et")
+
+        FILTER_NAME_TO_FILTER_AND_LABEL = {
+            "all": (None, "All"),
+            "executorch": (is_executorch_symbol, "ExecuTorch"),
+            "executorch_text": (lambda s: is_executorch_symbol(s) and s.symbol_type.lower() == "t", "ExecuTorch .text")
+        }
+
+        filter_func, label = FILTER_NAME_TO_FILTER_AND_LABEL.get(self.filter, FILTER_NAME_TO_FILTER_AND_LABEL["all"])
+        print_table(filter_func, label)
+
+
+if __name__ == "__main__":
+    import argparse
+
+    parser = argparse.ArgumentParser(
+        description="Process ELF file and linker map file."
+    )
+    parser.add_argument(
+        "-e", "--elf-file-path", required=True, help="Path to the ELF file"
+    )
+    parser.add_argument(
+        "-f",
+        "--filter",
+        required=False,
+        default="all",
+        help="Filter symbols by pre-defined filters",
+        choices=["all", "executorch", "executorch_text"],
+    )
+    parser.add_argument(
+        "-p",
+        "--toolchain-prefix",
+        required=False,
+        default="",
+        help="Optional toolchain prefix for nm",
+    )
+
+    args = parser.parse_args()
+    p = Parser(args.elf_file_path, args.toolchain_prefix, filter=args.filter)
+    p.print()