Nine `PNode`-typed codegen procs become `AnyNode`, all pure readers:
`bodyCanRaise` (the consumer of the `canRaise` work), `isAssignedImmediately`,
`branchHasTooBigRange`, `hasNoInit`, `reifiedOpenArray`,
`skipTrivialIndirections`, `isSimpleExpr`, `isConstClosure` and `fewCmps`.
The signatures are the small part. A migrated proc that nothing calls with a
`BNode` is not even type-checked, so the substance is `grindPredicates`: every
one of them runs on BOTH spellings of the SAME node, at EVERY node of every
graded body, inside the walk `grindLockstep` was already doing. 67_721 nodes
on the reference target, 0 disagreements.
Two things had to be gated, and neither by widening a guard until the run went
green.
The tolerated `(ht . <sym>)` type difference is benign for the vocabulary check
and NOT benign for a predicate that reads `typ` — and because the predicates
recurse, one excused node poisons every ancestor's answer too. `grindLockstep`
now reports whether a subtree is free of it, and only clean subtrees are
graded.
`isAssignedImmediately` and `fewCmps` hand `n.typ` to `getSize`/`mapType`,
which are total only over types the C backend can lay out. Asked at an
arbitrary node they meet a `tyGenericParam` or a `tyAnything` and abort — that
is a question with no answer in either spelling, not a disagreement between
them. Both are graded FROM THE PARENT, at the position production calls them
from. Declarative subtrees are skipped for the same reason, along the boundary
`bodyCanRaise` already draws.
Both exclusions are counted and printed beside the graded count, so a run that
grades nothing cannot pass for a run that grades everything.
`tools/icgrind` versions the grind target, because two ways of silently
getting no coverage turned up while writing it: the main module's routines are
never graded, and `ast2nif` defers only `nkStmtList` bodies, so a one-line
`proc f(x: int): int = case x ...` is invisible to the oracle. Shapes added
for `branchHasTooBigRange` and `fewCmps` produced exactly zero coverage until
both were found by counting rather than assumed.
Verified: 215/215 byte-identical `.c` against HEAD on the default path;
sabotaging `isAtom` and sabotaging the parent-driven node selection each make
the grinder fail on the first body it reaches.
Recorded rather than papered over: `isConstClosure` is graded only on its false
side — the whole closure contains one `nkClosure` node.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XEF7FJvUkGKvG9LSGuEaNR
837082eb89