cperf

C11/C17 performance notes, small examples, and cperf-lint written in C11. Light C++ remarks appear where the same pattern applies.

Part of XPerf. Shared docs: docs/README.md. Severity presets. Guide v0. Wall-clock evidence gates cp-alloc-hot, cp-realloc-grow-one and cp-printf-hot; cp-strlen-in-cond (hint) and cp-strcat-hot (off) have none yet. cp-sprintf-hot, cp-fopen-hot, cp-gettime-hot, and cp-wide-bool-flags are hint with JSONL and are not corpus-triaged. cp-regex-hot is hint with JSONL (about 9.7×) and is not corpus-triaged. Corpus r1–r3 remains lint dogfood.

ContentsCopy Anchor Link

• English guide (v0) — from docs/guide-src/
• cperf-lint — C11 checker
• Corpus pins

FocusCopy Anchor Link

Arenas / pools, capacity doubling, strlen-in-cond (cp-strlen-in-cond), hot-path stdio (cp-printf-hot), strcat-in-loop (cp-strcat-hot), formatted writes, file opens, clock samples in loops, and honest measurement notes. Claims without a local bench or citation stay provisional; corpus counts are lint dogfood.

Build examplesCopy Anchor Link

cc -std=c17 -O2 -o /tmp/m01 examples/m01_arena.c && /tmp/m01
cc -std=c17 -O2 -o /tmp/p01 examples/p01_soa.c && /tmp/p01

Run lintCopy Anchor Link

cd packages/cperf/cperf-lint
make
./cperf-lint path/to/sources --preset app          # alloc/realloc=error; strlen, later hints, and cp-regex-hot=hint; printf/strcat=off
./cperf-lint path/to/sources --preset all          # every rule error
./cperf-lint path/to/sources --severity cp-printf-hot=off
make self-lint   # dogfood: lint src/ + include/, must be clean
make test        # fixtures + severity smoke + self-lint

From package root: bash scripts/smoke-lint.sh.

Exit code 1 only when an error-severity finding exists (hints print but exit 0 unless --strict-hints). Exit 2 on usage/IO errors.

LayoutCopy Anchor Link

docs/guide-src/   chapter sources (00_head … 04_hot_calls, 99_tail)
docs/             assembled guide + corpus.md + evidence-policy.md
evidence/         wall-clock gates: cp-alloc-hot, cp-realloc-grow-one, cp-printf-hot (*.md + *.jsonl)
examples/         tiny C demos + bench/ harnesses
cperf-lint/       C11 checker (src/, include/, Makefile) + fixtures
scripts/          regen-evidence-*.sh, run-static-vs-o2.sh