Counts every `newSym` mint, by kind, and reports on exit. A gensym's number is
its item id, so ONE extra symbol anywhere shifts every later name in the
generated C — which makes a mint count far more sensitive than diffing output,
and localises a difference by symbol kind instead of by whichever file happened
to show it.
It was written to answer a question I had reported wrongly. Comparing the
cursor-driven and `PNode`-driven builds over the whole compiler showed 3 of 215
`.c` files differing, and I attributed 2 of them to the compiler being
nondeterministic. That control was invalid: I had compared two runs across an
edit to `ccgexprs.nim`, so what I read as nondeterminism was line numbers moving
inside assertion strings. The compiler is DETERMINISTIC — same binary, same
source, twice, 0 of 215 differ.
What the count establishes: the two builds mint exactly the same symbols,
515_551 of them, with no per-kind difference at all. So nothing in the cursor
path creates or skips a symbol, and the earlier gensym-numbered differences —
which had zero non-gensym lines — were ordering, not extra work.
On the current tree the comparison is clean: cursor-driven and `PNode`-driven
produce BYTE-IDENTICAL `.c` for all 215 files of `compiler/nim.nim`. I have not
isolated why the same comparison showed 3 differences one commit earlier; the
commit between was behaviour-neutral by inspection, so I am recording the
observation rather than a claim about its cause.
Verified: both build configurations compile; the diagnostic is behind a define
and costs nothing otherwise.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XEF7FJvUkGKvG9LSGuEaNR
603953376d