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Chris Tate
fa7bc7c7a0
A build now names the functions of the program's own files that compile
to the dynamic tier and likely run often, so a slow program with a little
untyped code says where the time goes:
warning SC6101: 3 functions that likely run often use untyped values, which runs slower than typed code:
advance (nbody.js:22): untyped JavaScript file, in a loop
...
- The functions come from the tier assignment lowering already makes
(Lowerer.dynamicFunctions). Without a profile, a function counts as
likely hot when a dynamic operation runs inside one of its loops, when
a loop calls it, or when it calls itself (lowering/dynamic-tier.ts).
- A function is named only when its source says why its values are
untyped: an `any` (for a for...of variable, the value it iterates), an
untyped JSON.parse result, or an untyped JavaScript file. Generated
%dyn.* helpers, module top levels and functions that are dynamic for an
operation without a static lowering are left out.
- At most five functions are named, most likely hot first, with the
total; dynamic-tier code in npm packages is counted per package on one
line. All of the warning's text is in diagnostics/dynamic-tier.ts.
- SC6101 opens the SC61xx band, performance notes, with a new
"performance" category in the diagnostics envelope; SC60xx stay the
divergences.
- scriptc build prints it after the divergence warnings, and the
executable cache stores it with the entry, so a cached build (including
the CLI's routed fast path) repeats it. scriptc coverage reports it, and
a comment-only edit no longer replays a verdict that carries it, since
its text holds line numbers.
- --no-dynamic-tier-warning leaves it out of build and coverage;
coverage --fail-on=dynamic fails on it.
- Docs: coverage.mdx (Dynamic tier, Gating builds and CI, the envelope
categories) and cli.mdx.