cargo-bsize

Analyze Rust binary size.

Install

cargo binstall cargo-bsize

Use

cargo bsize
cargo bsize --cdylib rolldown_binding path/to/rolldown
cargo bsize --staticlib my_ffi_lib path/to/project

A staticlib is an archive of unlinked objects, so it is first linked into a shared library with cc (every member kept, dead code stripped, symbols the host provides left unresolved) and that is what gets analyzed.

The output is a Markdown report that can be fed into an agent. It shows:

• Binary size by object-file section
• Linker input, archive-member, and exported-root provenance
• Code size by Rust function
• Static data size
• Rust type layout
• Code size by crate
• Code size by generic monomorphization
• Duplicate Cargo dependencies
• Duplicate function bodies
• Duplicate static data
• Repeated string literals
• Inlined Rust code
• LLVM inlining, instruction-growth, and stack-frame decisions
• Panic-path overhead
• Unwind frame and exception-cleanup ownership
• Rust formatting overhead
• Trait-object dynamic dispatch
• Assembly instruction patterns
• Rust source-line attribution
• Assembly and input-object reference graph with root/API retention, shared cohorts, coverage gains, and shortest why-live paths
• Ranked graph-coverage gaps and likely missing entries
• And more.

Prior art

• cargo-bloat
• cargo-llvm-lines
• cargo-show-asm

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