FastLED Symbol Analysis

This document describes the new generic symbol analysis functionality that works across all supported platforms including UNO, ESP32, and others.

Overview

The symbol analysis tool provides comprehensive analysis of compiled ELF files to help identify optimization opportunities and understand binary size allocation. Unlike the previous ESP32-specific implementation, this tool:

✅ Works on ALL platforms (UNO, ESP32, Teensy, STM32, etc.)
✅ Pulls ALL symbols without filtering or classification
✅ No FastLED-specific filtering - analyzes everything
✅ Generic and extensible for any platform with build_info.json

Quick Start

Analyze a specific platform

bash

cd ci
uv run symbol_analysis.py --board uno
uv run symbol_analysis.py --board esp32dev

Run analysis on all available platforms

bash

uv run demo_symbol_analysis.py

Use in GitHub Actions

bash

uv run symbol_analysis_runner.py --board uno --example Blink

Files

symbol_analysis.py - Main generic symbol analysis tool
symbol_analysis_runner.py - GitHub Actions wrapper
demo_symbol_analysis.py - Demonstration script for multiple platforms
SYMBOL_ANALYSIS.md - This documentation file

Example Output

UNO Platform Results

================================================================================
UNO SYMBOL ANALYSIS REPORT
================================================================================

SUMMARY:
  Total symbols: 51
  Total symbol size: 3767 bytes (3.7 KB)

LARGEST SYMBOLS (all symbols, sorted by size):
   1.   1204 bytes - ClocklessController<...>::showPixels(...)
   2.    572 bytes - CFastLED::show(unsigned char) [clone .constprop.18]
   3.    460 bytes - main
   4.    204 bytes - CPixelLEDController<...>::show(...)
   5.    168 bytes - CPixelLEDController<...>::showColor(...)

SYMBOL TYPE BREAKDOWN:
  t: 19 symbols, 2710 bytes (2.6 KB)
  T: 14 symbols, 904 bytes (0.9 KB)
  b: 15 symbols, 89 bytes (0.1 KB)
  d: 3 symbols, 64 bytes (0.1 KB)

ESP32 Platform Results

================================================================================
ESP32DEV SYMBOL ANALYSIS REPORT
================================================================================

SUMMARY:
  Total symbols: 2503
  Total symbol size: 237092 bytes (231.5 KB)

LARGEST SYMBOLS (all symbols, sorted by size):
   1.  12009 bytes - _vfprintf_r
   2.  11813 bytes - _svfprintf_r
   3.   8010 bytes - _vfiprintf_r
   4.   7854 bytes - _svfiprintf_r
   5.   4192 bytes - port_IntStack

SYMBOL TYPE BREAKDOWN:
  T: 1240 symbols, 156230 bytes (152.6 KB)
  t: 371 symbols, 45841 bytes (44.8 KB)
  d: 475 symbols, 13032 bytes (12.7 KB)
  D: 60 symbols, 9421 bytes (9.2 KB)
  W: 126 symbols, 5209 bytes (5.1 KB)

ESP32S3 Platform Results

================================================================================
ESP32S3 SYMBOL ANALYSIS REPORT
================================================================================

SUMMARY:
  Total symbols: 2831
  Total symbol size: 260710 bytes (254.6 KB)

LARGEST SYMBOLS (all symbols, sorted by size):
   1.  11309 bytes - _vfprintf_r
   2.  11118 bytes - _svfprintf_r
   3.   7337 bytes - _svfiprintf_r
   4.   7265 bytes - _vfiprintf_r
   5.   4192 bytes - port_IntStack
   6.   1164 bytes - printBeforeSetupInfo()
   7.    828 bytes - fl::RmtController5::loadPixelData(PixelIterator&)

SYMBOL TYPE BREAKDOWN:
  T: 1416 symbols, 172591 bytes (168.5 KB)
  t: 429 symbols, 48854 bytes (47.7 KB)
  d: 529 symbols, 14189 bytes (13.9 KB)
  D: 72 symbols, 9831 bytes (9.6 KB)
  W: 122 symbols, 5457 bytes (5.3 KB)

Output Files

The tool generates JSON files with complete symbol data:

.build/{board}_symbol_analysis.json - Complete analysis results

JSON Structure

json

{
  "summary": {
    "board": "uno",
    "total_symbols": 51,
    "total_size": 3767,
    "largest_symbols": [...],
    "type_breakdown": {...},
    "dependencies": {...}
  },
  "all_symbols_sorted_by_size": [
    {
      "address": "00001240",
      "size": 1204,
      "type": "t",
      "name": "_ZN19ClocklessController...",
      "demangled_name": "ClocklessController<...>::showPixels(...)"
    },
    ...
  ],
  "dependencies": {
    "module.cpp.o": ["symbol1", "symbol2", ...]
  }
}

Supported Platforms

The tool automatically detects and works with any platform that has:

A build_info.json file in .build/{platform}/
Standard toolchain tools (nm, c++filt) in the build info aliases

Successfully tested platforms:

✅ UNO (AVR) - 51 symbols, 3.7 KB
✅ ESP32DEV (Xtensa) - 2503 symbols, 231.5 KB
✅ ESP32S3 (Xtensa) - 2831 symbols, 254.6 KB
✅ TEENSY31 (ARM Cortex-M4) - 238 symbols, 10.9 KB
✅ TEENSYLC (ARM Cortex-M0+) - 241 symbols, 9.1 KB
✅ DIGIX (ARM Cortex-M3) - 298 symbols, 17.9 KB
✅ STM32 (ARM Cortex-M3) - 311 symbols, 15.6 KB

Key Improvements

From ESP32-specific to Generic

Before (ESP32 only):

python

# Hard-coded ESP32 board detection
esp32_boards = ["esp32dev", "esp32", "esp32s2", ...]

# FastLED-specific filtering
if any(keyword in search_text for keyword in [
    "fastled", "cfastled", "crgb", "hsv", ...]):
    fastled_symbols.append(symbol_info)

After (Generic):

python

# Auto-detect any platform with build_info.json
for item in build_dir.iterdir():
    if item.is_dir() and (item / "build_info.json").exists():
        available_boards.append((build_info_file, item.name))

# No filtering - analyze ALL symbols
symbols.append(symbol_info)  # Everything included

Symbol Analysis Improvements

No Classification - All symbols are included without filtering
Complete Demangling - All C++ symbols are properly demangled
Platform Agnostic - Works with any toolchain (AVR, ARM, Xtensa, etc.)
Size-based Sorting - All results sorted by symbol size for easy optimization targeting

GitHub Actions Integration

The symbol_analysis_runner.py script provides GitHub Actions compatibility:

yaml

- name: Run Symbol Analysis
  run: python ci/symbol_analysis_runner.py --board uno --example Blink

This runner:

Validates build_info.json exists
Handles errors gracefully with --skip-on-failure
Provides proper exit codes for CI/CD

Migration from ESP32 Analysis

If you were using the old ESP32-specific analysis:

Old command:

bash

cd ci/ci && python esp32_symbol_analysis.py

New command:

bash

cd ci && uv run symbol_analysis.py --board esp32dev

The new tool provides all the same information plus:

Support for more platforms
ALL symbols instead of just FastLED ones
Better error handling
Cleaner output format

Advanced Usage

Analyzing Custom Platforms

To add support for a new platform:

Ensure the platform builds correctly with PlatformIO
Verify build_info.json is generated in .build/{platform}/
Run: uv run symbol_analysis.py --board {platform}

Batch Analysis

bash

# Analyze all available platforms
uv run demo_symbol_analysis.py

# Analyze specific platforms in sequence
for board in uno esp32dev teensy31; do
    uv run symbol_analysis.py --board $board
done

Integration with Build Systems

python

# In your Python build script
from ci.ci.symbol_analysis import main as analyze_symbols
import sys

# Override arguments
sys.argv = ["symbol_analysis.py", "--board", "uno"]
analyze_symbols()

Troubleshooting

Common Issues

"build_info.json not found"
- Solution: Compile the platform first: uv run ci/ci-compile.py {board} --examples Blink
"KeyError: 'board_name'"
- Solution: The board name in the directory doesn't match the key in build_info.json
- Check: cat .build/{board}/build_info.json | jq 'keys'
"Tool not found"
- Solution: The toolchain isn't installed or path is incorrect in build_info.json

Debug Mode

To debug issues, run with verbose Python output:

bash

uv run python -v symbol_analysis.py --board uno

Contributing

When adding new features:

Maintain platform independence
Don't add filtering logic
Test on multiple platforms
Update this documentation
Add tests to verify functionality

Performance

Platform analysis times (approximate):

UNO: < 1 second (51 symbols)
Teensy: < 2 seconds (238-241 symbols)
STM32: < 3 seconds (311 symbols)
ESP32: < 10 seconds (2503 symbols)

The tool scales well with symbol count and provides progress feedback during demangling.