Add an additional binary ELF size differ we can use for size differen…

…ces and docs (project-chip#37325)

* Add the binary size differ

* Add documentation for tooling

* Restyle

* Fix text

---------

Co-authored-by: Andrei Litvin <andreilitvin@google.com>

docs/tools/index.md

@@ -28,6 +28,7 @@ Source files for these tools are located at `scripts/tools`.
 
 ../scripts/tools/memory/README
 ../scripts/tools/spake2p/README
+../scripts/tools/ELF_SIZE_TOOLING
 
 ```
 

scripts/tools/ELF_SIZE_TOOLING.md

@@ -0,0 +1,63 @@
+# ELF binary size information
+
+## Individual size information
+
+`file_size_from_nm.py` is able to build an interactive tree map of
+methods/namespaces sizes within an elf binary.
+
+Use it to determine how much space specific parts of the code take. For example:
+
+```
+./scripts/tools/file_size_from_nm.py \
+    --zoom '::chip::app'             \
+    ./out/qpg-qpg6105-light/chip-qpg6105-lighting-example.out
+```
+
+could result in a graph like:
+
+![image](./FileSizeOutputExample.png)
+
+## Determine difference between two binaries
+
+`binary_elf_size_diff` provides the ability to compare two elf files. Usually
+you can build the master branch of a binary and save it somewhere like
+`./out/master.elf` and then re-build with changes and compare.
+
+Example runs:
+
+```
+> ~/devel/chip-scripts/bindiff.py \
+  ./out/qpg-qpg6105-light/chip-qpg6105-lighting-example.out \
+  ./out/qpg-master.out
+
+Type       Size  Function
+-------  ------  -----------------------------------------------------------------------------------------------------------------------
+CHANGED    -128  chip::app::CodegenDataModelProvider::WriteAttribute(chip::app::DataModel::WriteAttributeRequest const&, chip::app::A...
+CHANGED     -76  chip::app::InteractionModelEngine::CheckCommandExistence(chip::app::ConcreteCommandPath const&, chip::app::DataModel...
+CHANGED     -74  chip::app::reporting::Engine::CheckAccessDeniedEventPaths(chip::TLV::TLVWriter&, bool&, chip::app::ReadHandler*)
+REMOVED     -58  chip::app::DataModel::EndpointFinder::EndpointFinder(chip::app::DataModel::ProviderMetadataTree*)
+REMOVED     -44  chip::app::DataModel::EndpointFinder::Find(unsigned short)
+CHANGED      18  chip::app::WriteHandler::WriteClusterData(chip::Access::SubjectDescriptor const&, chip::app::ConcreteDataAttributePa...
+ADDED       104  chip::app::DataModel::ValidateClusterPath(chip::app::DataModel::ProviderMetadataTree*, chip::app::ConcreteClusterPat...
+ADDED       224  chip::app::WriteHandler::CheckWriteAllowed(chip::Access::SubjectDescriptor const&, chip::app::ConcreteDataAttributeP...
+TOTAL       -34
+
+
+```
+
+```
+> ~/devel/chip-scripts/bindiff.py \
+  --output csv --skip-total       \
+  ./out/qpg-qpg6105-light/chip-qpg6105-lighting-example.out ./out/qpg-master.out
+
+Type,Size,Function
+CHANGED,-128,"chip::app::CodegenDataModelProvider::WriteAttribute(chip::app::DataModel::WriteAttributeRequest const&, chip::app::AttributeValueDecoder&)"
+CHANGED,-76,"chip::app::InteractionModelEngine::CheckCommandExistence(chip::app::ConcreteCommandPath const&, chip::app::DataModel::AcceptedCommandEntry&)"
+CHANGED,-74,"chip::app::reporting::Engine::CheckAccessDeniedEventPaths(chip::TLV::TLVWriter&, bool&, chip::app::ReadHandler*)"
+REMOVED,-58,chip::app::DataModel::EndpointFinder::EndpointFinder(chip::app::DataModel::ProviderMetadataTree*)
+REMOVED,-44,chip::app::DataModel::EndpointFinder::Find(unsigned short)
+CHANGED,18,"chip::app::WriteHandler::WriteClusterData(chip::Access::SubjectDescriptor const&, chip::app::ConcreteDataAttributePath const&, chip::TLV::TLVReader&)"
+ADDED,104,"chip::app::DataModel::ValidateClusterPath(chip::app::DataModel::ProviderMetadataTree*, chip::app::ConcreteClusterPath const&, chip::Protocols::InteractionModel::Status)"
+ADDED,224,"chip::app::WriteHandler::CheckWriteAllowed(chip::Access::SubjectDescriptor const&, chip::app::ConcreteDataAttributePath const&)"
+
+```

scripts/tools/binary_elf_size_diff.py

@@ -0,0 +1,218 @@
+#!/usr/bin/env -S python3 -B
+#
+#    Copyright (c) 2025 Project CHIP Authors
+#
+#    Licensed under the Apache License, Version 2.0 (the "License");
+#    you may not use this file except in compliance with the License.
+#    You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS,
+#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#    See the License for the specific language governing permissions and
+#    limitations under the License.
+#
+
+# Processes 2 ELF files via `nm` and outputs the
+# diferences in size. Example calls:
+#
+#  scripts/tools/bindiff.py    \
+#     ./out/updated_binary.elf \
+#     ./out/master_build.elf
+#
+#  scripts/tools/bindiff.py    \
+#     --output csv             \
+#     --no-demangle            \
+#     ./out/updated_binary.elf \
+#     ./out/master_build.elf
+#
+#
+# Requires:
+#   - click
+#   - coloredlogs
+#   - cxxfilt
+#   - tabulate
+
+import csv
+import logging
+import os
+import subprocess
+import sys
+from dataclasses import dataclass
+from enum import Enum, auto
+from pathlib import Path
+
+import click
+import coloredlogs
+import cxxfilt
+import tabulate
+
+
+@dataclass
+class Symbol:
+    symbol_type: str
+    name: str
+    size: int
+
+
+# Supported log levels, mapping string values required for argument
+# parsing into logging constants
+__LOG_LEVELS__ = {
+    "debug": logging.DEBUG,
+    "info": logging.INFO,
+    "warn": logging.WARN,
+    "fatal": logging.FATAL,
+}
+
+
+class OutputType(Enum):
+    TABLE = (auto(),)
+    CSV = (auto(),)
+
+
+__OUTPUT_TYPES__ = {
+    "table": OutputType.TABLE,
+    "csv": OutputType.CSV,
+}
+
+
+def get_sizes(p: Path, no_demangle: bool):
+    output = subprocess.check_output(
+        ["nm", "--print-size", "--size-sort", "--radix=d", p.as_posix()]
+    ).decode("utf8")
+
+    result = {}
+
+    for line in output.split("\n"):
+        if not line.strip():
+            continue
+
+        _, size, t, name = line.split(" ")
+        size = int(size, 10)
+
+        if not no_demangle:
+            name = cxxfilt.demangle(name)
+
+        result[name] = Symbol(symbol_type=t, name=name, size=size)
+
+    return result
+
+
+def default_cols():
+    try:
+        # if terminal output, try to fit
+        return os.get_terminal_size().columns - 29
+    except Exception:
+        return 120
+
+
+@click.command()
+@click.option(
+    "--log-level",
+    default="INFO",
+    show_default=True,
+    type=click.Choice(list(__LOG_LEVELS__.keys()), case_sensitive=False),
+    help="Determines the verbosity of script output.",
+)
+@click.option(
+    "--output",
+    default="TABLE",
+    show_default=True,
+    type=click.Choice(list(__OUTPUT_TYPES__.keys()), case_sensitive=False),
+    help="Determines the type of the output (use CSV for easier parsing).",
+)
+@click.option(
+    "--skip-total",
+    default=False,
+    is_flag=True,
+    help="Skip the output of a TOTAL line (i.e. a sum of all size deltas)"
+)
+@click.option(
+    "--no-demangle",
+    default=False,
+    is_flag=True,
+    help="Skip CXX demangling. Note that this will not deduplicate inline method instantiations."
+)
+@click.option(
+    "--style",
+    default="simple",
+    show_default=True,
+    help="tablefmt style for table output (e.g.: simple, plain, grid, fancy_grid, pipe, orgtbl, jira, presto, pretty, psql, rst)",
+)
+@click.option(
+    "--name-truncate",
+    default=default_cols(),
+    show_default=True,
+    type=int,
+    help="Truncate function name to this length (for table output only). use <= 10 to disable",
+)
+@click.argument("f1", type=Path)
+@click.argument("f2", type=Path)
+def main(
+    log_level,
+    output,
+    skip_total,
+    no_demangle,
+    style: str,
+    name_truncate: int,
+    f1: Path,
+    f2: Path,
+):
+    log_fmt = "%(asctime)s %(levelname)-7s %(message)s"
+    coloredlogs.install(level=__LOG_LEVELS__[log_level], fmt=log_fmt)
+
+    r1 = get_sizes(f1, no_demangle)
+    r2 = get_sizes(f2, no_demangle)
+
+    output_type = __OUTPUT_TYPES__[output]
+
+    # at this point every key has a size information
+    # We are interested in sizes that are DIFFERENT (add/remove or changed)
+    delta = []
+    total = 0
+    for k in set(r1.keys()) | set(r2.keys()):
+        if k in r1 and k in r2 and r1[k].size == r2[k].size:
+            continue
+
+        # At this point the value is in v1 or v2
+        s1 = r1[k].size if k in r1 else 0
+        s2 = r2[k].size if k in r2 else 0
+        name = r1[k].name if k in r1 else r2[k].name
+
+        if k in r1 and k in r2:
+            change = "CHANGED"
+        elif k in r1:
+            change = "ADDED"
+        else:
+            change = "REMOVED"
+
+        if (
+            output_type == OutputType.TABLE
+            and name_truncate > 10
+            and len(name) > name_truncate
+        ):
+            name = name[: name_truncate - 4] + "..."
+
+        delta.append([change, s1 - s2, name])
+        total += s1 - s2
+
+    delta.sort(key=lambda x: x[1])
+    if not skip_total:
+        delta.append(["TOTAL", total, ""])
+
+    HEADER = ["Type", "Size", "Function"]
+
+    if output_type == OutputType.TABLE:
+        print(tabulate.tabulate(delta, headers=HEADER, tablefmt=style))
+    elif output_type == OutputType.CSV:
+        writer = csv.writer(sys.stdout)
+        writer.writerow(HEADER)
+        writer.writerows(delta)
+    else:
+        raise Exception("Unknown output type: %r" % output)
+
+
+if __name__ == "__main__":
+    main(auto_envvar_prefix="CHIP")