Bloaty

A tool for analyzing binary size and feature impact across Rust workspace members. Bloaty helps you understand how different features affect your binary sizes and identify potential optimization opportunities.

Features

• Analyze binary sizes across workspace members
• Compare feature impact on binary sizes
• Support for multiple output formats (text, JSON, JSONL)
• Integration with cargo-bloat, cargo-llvm-lines, and cargo-size
• Detailed reporting of size differences between features

Installation

cargo install --path packages/bloaty

Usage

Basic usage:

cargo run --bin bloaty

This will analyze all workspace members and generate reports in all supported formats.

Command Line Options

All list arguments (packages, skip-packages, skip-features, tool, output-format) support both comma-separated lists and multiple arguments.

• -p, --package <PACKAGE>: Specify packages to analyze

  # Using comma-separated list
  --package pkg1,pkg2,pkg3
  # Using multiple arguments
  --package pkg1 --package pkg2 --package pkg3
  

• --skip-packages <SKIP_PACKAGES>: Packages to skip

  # Using comma-separated list
  --skip-packages pkg1,pkg2
  # Using multiple arguments
  --skip-packages pkg1 --skip-packages pkg2
  

• --skip-features <SKIP_FEATURES>: Features to skip

  # Using comma-separated list
  --skip-features test,bench,dev
  # Using multiple arguments
  --skip-features test --skip-features bench
  

• -t, --tool <TOOL>: Tools to use (options: bloat, llvm-lines, size)

  # Using comma-separated list
  --tool bloat,size
  # Using multiple arguments
  --tool bloat --tool size
  

• --report-file <REPORT_FILE>: Custom report file name (without extension)

• --output-format <FORMAT>: Output format (text, json, jsonl, all)

  # Using comma-separated list
  --output-format text,json
  # Using multiple arguments
  --output-format text --output-format json
  # Using 'all' for all formats
  --output-format all
  

Examples

Analyze specific packages:

# Using comma-separated list
cargo run --bin bloaty -- -p package1,package2

# Using multiple arguments
cargo run --bin bloaty -- -p package1 -p package2

Skip certain features:

# Using comma-separated list
cargo run --bin bloaty -- --skip-features test,bench,dev

# Using multiple arguments
cargo run --bin bloaty -- --skip-features test --skip-features bench

Use specific tools:

# Using comma-separated list
cargo run --bin bloaty -- -t bloat,size

# Using multiple arguments
cargo run --bin bloaty -- -t bloat -t size

Generate specific output formats:

# Using comma-separated list
cargo run --bin bloaty -- --output-format text,json

# Using multiple arguments
cargo run --bin bloaty -- --output-format text --output-format json

# Generate all formats
cargo run --bin bloaty -- --output-format all

Custom report file:

cargo run --bin bloaty -- --report-file analysis

Output Formats

Text Format

Human-readable format showing package, target, and feature sizes with differences.

Example:

Package: my_crate
===================

Target: my_target
-------------------
Base size: 1.2 MB
Feature: default        | Size: 1.2 MB | Diff: +0 B
Feature: extra          | Size: 1.5 MB | Diff: +300 KB
Feature: minimal        | Size: 900 KB | Diff: -300 KB

JSON Format

Complete analysis in a single JSON object, useful for programmatic processing.

JSONL Format

Line-delimited JSON format, with each line representing a single event in the analysis process. Useful for streaming and real-time processing.

Example:

{"type":"package_start","name":"my_crate","timestamp":1234567890}
{"type":"target_start","package":"my_crate","target":"my_target","timestamp":1234567890}
{"type":"base_size","package":"my_crate","target":"my_target","size":1258291,"size_formatted":"1.2 MB","timestamp":1234567890}
{"type":"feature","package":"my_crate","target":"my_target","feature":"default","size":1258291,"diff":0,"diff_formatted":"+0 B","size_formatted":"1.2 MB","timestamp":1234567890}

Dependencies

• cargo-bloat
• cargo-llvm-lines
• cargo-size

Make sure these tools are installed before running bloaty:

cargo install cargo-bloat cargo-llvm-lines cargo-size