Small Binary Toolchain, Linker, And Post-Link Optimization

This page documents the bounded production evidence for small native binaries,

native linker layout, and post-link optimization. It covers section splitting,

dead-code and dead-data elimination, identical code/data folding, symbol

visibility, source-owned linker-script policy, thin whole-program summaries,

profile freshness, relocation-safe post-link layout, stripped artifacts,

debug-capable artifacts, and release size budgets.

Run the bounded gates with:

make tiny-binary-check
make native-linker-check
make native-post-link-check

These gates do not run the full release or self-host matrix. They validate the

source-owned toolchain evidence listed below.

Evidence Files

• native-toolchain/schema.tsv;
• native-toolchain/section-policy.tsv;
• native-toolchain/linker-script-policy.tsv;
• native-toolchain/post-link-policy.tsv;
• native-toolchain/verification-cases.tsv;
• native-toolchain/fixtures/valid-native-toolchain.json;
• release/native-toolchain-size-report.tsv;
• release/native-toolchain-section-report.tsv;
• release/native-toolchain-symbol-report.tsv;
• release/native-toolchain-callgraph-report.tsv;
• release/native-toolchain-profile-report.tsv;
• release/native-toolchain-post-link-report.tsv;
• release/native-toolchain-relocations.tsv;
• release/native-toolchain-thin-summary.tsv;
• perf/native-toolchain-benchmarks.tsv;
• compat/native-toolchain-contract.tsv;
• tools/native-toolchain-check.py.

Tiny Binary Policy

Release-size variants must be built from fine-grained function and data

sections. Unreachable text and data are removed before release artifacts are

accepted. Eligible identical text and readonly data are folded only when the

symbol and section reports record the retained representative.

The gate rejects:

NATIVE_TOOLCHAIN_SIZE_BUDGET
NATIVE_TOOLCHAIN_SYMBOL
NATIVE_TOOLCHAIN_SECTION

release/native-toolchain-size-report.tsv records both stripped and

debug-capable variants where supported. Stripped variants remove non-exported

symbol information. Debug-capable variants keep review/debug metadata and still

must fit the configured budget.

Native Linker Contract

The native linker contract is source owned. Linker scripts or equivalent 0x0

metadata define memory regions, fixed-address sections, output-section mapping,

firmware image placement, and hosted binary placement.

The gate rejects:

NATIVE_TOOLCHAIN_LINKER_SCRIPT

release/native-toolchain-section-report.tsv,

release/native-toolchain-symbol-report.tsv, and

release/native-toolchain-thin-summary.tsv are the release evidence for native

linker layout. Output sections must map existing input sections and memory

regions must not overlap.

Thin Summary And Profile Data

Thin whole-program summary data records cross-module imports, cross-package

inline decisions, devirtualization, and bounded parallel backend work. Profile

data records workload identity, hash, profile kind, age, hot ordering, and cold

split decisions.

The gate rejects stale profile data:

NATIVE_TOOLCHAIN_PROFILE_STALE

Profile absence is not a correctness problem. When profile-guided layout is

used, profile age and hash evidence must be present and current.

Post-Link Layout

Post-link layout may reorder hot code, split cold code, and keep folded code

stable only when relocation evidence exists for every moved symbol.

The gate rejects:

NATIVE_TOOLCHAIN_RELOCATION

release/native-toolchain-post-link-report.tsv records before/after order,

action, relocation evidence, profile hash, and status for each moved symbol.

What This Does Not Overpromise

This page closes native performance Milestone 7 for the recorded hosted native

toolchain evidence. Direct hardware access, bare-metal output, QEMU or

equivalent emulator execution, compile-time incremental builds, and final

release-wide verification remain owned by later milestones.