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fix(ir): converge the comptime-int count surface (0083)

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Three adjacent cells of the shared count surface still diverged from the
rest; all now route through the same leaf+fold+narrow+diagnose path.

1. Aliased integer constraint bypassed the value-param range gate — only
   builtin constraint names matched intTypeRange, so Box(5_000_000_000)
   with `$K: Count` (Count :: u32) compiled and bound a truncated value.
   resolveValueParamArg (shared by both the struct AND type-fn binder) now
   resolves the constraint to its underlying builtin via
   canonicalIntConstraintName (Count -> u32, Small -> s8) before
   range-checking, so an aliased integer constraint behaves exactly like
   the builtin it names.

2. A named const with an expression RHS (M :: 2; N :: M + 1) did not fold
   as a count — moduleConstInt read only a literal RHS node. It now folds
   every const's RHS through the shared evalConstIntExpr, cycle-guarded
   (mutual / self cycles fold to null, not a stack overflow), and pass-0
   pre-registers expression-RHS consts. N :: M + 1 == 3 at every consumer:
   dim (direct + alias), Vector lane, value-param (struct + type-fn),
   inline for.

3. Stateful resolveArrayLen still fabricated length 0 after a failed fold;
   it now returns null -> the .unresolved sentinel (no fabrication). The
   binding's lowering never reaches sizeOf (alloca defers it; hasErrors
   aborts first) and a field access on an already-diagnosed .unresolved
   value is poison-suppressed (emitFieldError), so a failed-fold dim emits
   ONE clean diagnostic with no panic.

Regressions: examples/0146 (full positive matrix — every consumer x leaf
form), 1135 (aliased u32 + s8 overflow), 1136 (direct non-const dim halts
cleanly). The cascade cleanup also tightened 1502/1503 to one diagnostic.
Unit test added for moduleConstInt expression-folding + cycle detection.
This commit is contained in:
agra
2026-06-04 14:09:46 +03:00
parent e03c087e5a
commit a821323c3c
18 changed files with 328 additions and 33 deletions
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issues/0083-named-const-array-dimension-miscompiled.md
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@@ -167,6 +167,34 @@
> `examples/1132-diagnostics-array-dim-non-integral-float.sx`,
> `examples/1133-diagnostics-array-dim-negative-float.sx`,
> `examples/1134-diagnostics-value-param-u32-overflow.sx`.
>
> **Convergence — the last three count-surface cells (attempt 9).** Three
> adjacent cells of the SAME shared count surface still diverged. (1) An ALIASED
> integer constraint (`Count :: u32`; `$K: Count`) bypassed the value-param range
> gate — only BUILTIN constraint names matched `intTypeRange`, so
> `Box(5_000_000_000)` with `$K: Count` compiled and bound a truncated value. The
> gate (`Lowering.resolveValueParamArg`, shared by BOTH binders — struct +
> type-fn) now resolves the constraint to its underlying builtin
> (`canonicalIntConstraintName`: `Count` → u32, `Small` → s8) before
> range-checking, so an aliased integer constraint behaves exactly like the
> builtin it names. (2) A named const with an EXPRESSION RHS (`M :: 2; N :: M + 1`)
> did not fold as a count — `program_index.moduleConstInt` read only a LITERAL RHS
> node. It now folds every const's RHS through the shared `evalConstIntExpr`
> (cycle-guarded so `N :: N` / mutual cycles fold to null, not a stack overflow),
> and scanDecls pass-0 pre-registers expression-RHS consts; so `N :: M + 1` == 3
> at every count consumer (dim direct + alias, Vector lane, value-param struct +
> type-fn, `inline for`). (3) The stateful `Lowering.resolveArrayLen` STILL
> fabricated length 0 after a failed fold; it now returns null → the `.unresolved`
> sentinel (no fabrication), and the binding's lowering bails on it cleanly — a
> field access on an already-diagnosed `.unresolved` value stays silent
> (`emitFieldError`), so a failed-fold dim emits ONE clean diagnostic and never
> reaches the `sizeOf` panic. Files: `src/ir/program_index.zig` (+`.test.zig`),
> `src/ir/lower.zig`. Regressions: `examples/0146-types-comptime-count-matrix.sx`
> (the full positive matrix — every consumer × representative leaf form),
> `examples/1135-diagnostics-value-param-alias-constraint-overflow.sx` (aliased
> u32 + s8 overflow), `examples/1136-diagnostics-array-dim-nonconst-direct-no-crash.sx`
> (direct non-const dim halts cleanly, no fabrication / panic); the cascade
> cleanup also tightened `examples/1502`/`1503` to one diagnostic each.
## Symptom
A fixed array whose dimension is a module-global integer constant (`N :: 16;