[DO NOT MERGE] temporary: time clangd's module BMI rebuild on real projects - #29
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…jects Instruments module preparation (per-module prime duration, the preparation window and clangd's CPU at both ends) in the clangd engine's report, has the conformance runner wait for preparation and record it under MCPPLS_MEASURE_PREPARATION, and adds a linux-x64 workflow timing self-mcpp, real-xlings and self-mcppls cold and warm.
…hots per start Once preparation is idle and MCPPLS_MEASURE_PREPARATION is set, the clangd engine writes its log ring to <cache>/clangd-ring.log; the workflow keeps it, the server logs and a .pcm snapshot after the cold and the warm start, to tell whether the warm start built BMIs again.
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Temporary draft, opened only to get numbers from CI; it will be closed without merging.
Question: how much of an mcppls cold start is clangd rebuilding the modules' BMIs (module preparation)? The answer decides whether a consumer-side universal BMI (clangd reading an IFC the GCC build already wrote) is worth doing (mcpp-safe research).
What it changes (measurement only):
src/engine/clangd.cpp: the clangd engine's report carriespreparationTiming: each primed module's time from itsimport M;didOpen to its first diagnostics, the preparation window, and clangd's CPU seconds at both ends and now.src/bin/conformance.cpp: withMCPPLS_MEASURE_PREPARATIONset,--measurewaits for preparation to finish (up to 15 min) and records that report section..github/workflows/tmp-bmi-timing.yml: linux-x64, self-mcpp / real-xlings / self-mcppls, cold then warm; the table goes to the step summary, the JSON to thebmi-timingartifact.Locally, the
timingfixture: cold first navigation 3.4 s with a 2.1 s preparation window (std 1.8 s), clangd 4.9 of 5.1 CPU seconds in preparation; warm 0.8 s with nothing primed.