The stateless alias-registration array-dim path collapsed foldDimU32's
distinct .too_large / .below_min outcomes into null, so an oversized type
alias (Big :: [5000000000]s64) emitted the FALSE 'an array dimension is not
a compile-time integer constant' message while the direct form correctly
reported 'array dimension 5000000000 does not fit in u32'.
Add program_index.reportDimError as the single source of dim-error wording
(the stateful path now emits through it too) and type_bridge.foldArrayDim to
surface the DimU32 reason at the alias-registration site. An oversized/negative
alias dim now routes to reportDimError for the same precise message as the
direct form; a genuinely non-const alias dim keeps the alias-specific message.
Regression: examples/1131-diagnostics-array-dim-oversized-u32-alias.sx
Two remaining siblings in F0.4's comptime-int path.
1. Type-returning function with a value param used as a TYPE annotation
(`b : Make(N, s64)` where `Make :: ($K: u32, $T: Type) -> Type`):
- `isValueParamPosition` (semantic_diagnostics) now also skips a value
param of a `fn_ast_map` type-returning function, so `N` is not walked
as the type name "N" ("unknown type 'N'").
- `resolveParameterizedWithBindings` routes a type-returning-function
name to `instantiateTypeFunction` (the `.call` path already did).
- `instantiateTypeFunction` resolves a general return-type expression
(`return [K]T`) with bindings active — not just struct/union returns.
`Make(N, s64)`, `Make(M + 1, s64)`, `Make(3, s64)` all resolve to one
`[3]s64`.
2. Oversized dim/lane fold panicked the compiler (0087): an array dim /
Vector lane folded to a valid i64 (5e9) then narrowed to u32 with an
unchecked `@intCast`. New single gate `program_index.foldDimU32` folds
via `evalConstIntExpr` then range-checks `[min, maxInt(u32)]`; the three
narrowing sites (resolveArrayLen stateful + stateless, resolveVectorLane)
all route through it and emit a clean diagnostic + halt instead of
panicking. Value-param args stay i64 until used as a dim/lane, where the
same gate checks them.
Regressions: examples/0208 (value-param type function), examples/1130
(oversized array dim clean halt), examples/1503 (oversized Vector lane
clean halt). Marks issue 0087 RESOLVED.
Gate: zig build, zig build test, bash tests/run_examples.sh — 398 passed,
0 failed, 0 timed out.
Attempts 1–4 fixed the array-dimension paths but the same length-0
fabrication class survived on every other site that resolves a
compile-time integer. Unify them all on the single shared
`program_index.evalConstIntExpr` so they cannot diverge:
- All three Vector lane resolvers (resolveTypeCallWithBindings,
resolveParameterizedWithBindings, resolveArrayLiteralType) and both
generic value-param binders (instantiateGenericStruct,
instantiateTypeFunction) hand-rolled an `else => 0` switch. A
module-const lane `Vector(N, f32)` fabricated a 0-lane `<0 x float>`
(LLVM "huge alignment" abort); a value-param `Vec(N, f32)` fabricated
a 0 binding / wrong mangled name. They now fold through the shared
evaluator and emit a clean diagnostic + `.unresolved` on a non-const
operand (resolveVectorLane / resolveValueParamArg) — never 0.
- evalComptimeInt (inline-for bounds) delegated to the shared evaluator,
so `inline for 0..M` / `0..(M+1)` fold like array dims. The `<pack>.len`
leaf moved into the shared folder via a new `ctx.lookupPackLen`.
- The unknown-type semantic checker no longer walks a value-param
position (`Vector(N, …)` / `Vec(N, …)`) as a type name (was reporting
"unknown type 'N'").
- The parameterized-type-arg parser and the function-body lookahead
(hasFnBodyAfterArrow) accept a const-EXPRESSION in a value position, so
`Vector(M + 1, f32)` and `[M + 1]T` parse as a return type too (the
latter a pre-existing array-dim sibling that the same heuristic broke).
Regressions: examples/1501 (named-const + const-expr lane, direct +
alias, 3/4-lane reads), 1502 (runtime lane clean-halts, exit 1, no LLVM
crash), 0207 (Vec(N)/Vec(M+1) == Vec(3) instantiation), 0610 (inline-for
const bounds). Shared-evaluator unit test extended with the pack-len arm.
zig build && zig build test && bash tests/run_examples.sh: 395 passed,
0 failed.
A constant-FOLDABLE expression array dimension (`[M + 1]`, `[M * N]`,
`[N - M]`, nested `[M + N - 1]`, parenthesised `[(M + 1) * 2]`, mixing
untyped and typed module consts) was wrongly rejected as "not a
compile-time integer constant" even though every operand is
compile-time-known. Attempts 1-3 resolved only a bare named-const dim or
a literal; an expression dim must be EVALUATED, not rejected.
Fix: the shared dim resolver now routes the dimension through a single
constant integer-expression evaluator (`program_index.evalConstIntExpr`)
that folds integer `+ - * / %` and unary negate over literals and
named/typed module consts, recursively (parentheses carry no AST node).
The leaf-name lookup is delegated via `ctx.lookupDimName`, so the
stateful body-lowering path (`Lowering`, which also sees comptime
constants and generic `$N` values) and the stateless registration path
(`type_bridge.StatelessInner`, module consts only) share the EXACT SAME
folding logic and cannot diverge — an expression dim via a type alias
resolves identically to the direct form.
No-fabrication discipline unchanged: a genuinely non-comptime dimension
(runtime local, non-comptime call, unbound name) or arithmetic that
overflows / divides by zero still yields null -> `.unresolved` -> the
same clean compile-halting diagnostic, never a fabricated length.
- examples/0144-types-const-expr-array-dim.sx: every expression form,
direct vs alias, scalar / string / struct element types (fails on the
pre-fix compiler, passes after).
- examples/1129 re-pointed at a genuinely non-const dimension
(`[get()]s64`, a runtime call) so it still proves the stateless
clean-halt (a foldable expression is no longer an error).
- program_index.test.zig: unit test for evalConstIntExpr folding and
clean-halt-on-non-const.
A type alias whose dimension is a named const (`Arr :: [N]T`) resolves its
dimension eagerly during scanDecls pass 1, on the stateless registration path,
which can only read `module_const_map`. Typed consts (`N : s64 : 16`) register
only in pass 2 and a forward-declared untyped const had not registered yet, so
the stateless resolver saw an empty table, printed a non-fatal warning,
fabricated length 0, and continued — yielding a 0-byte alloca, garbage reads,
and a segfault for slice/struct elements.
- scanDecls pass 0 pre-registers every integer-valued module const before any
type alias resolves, so typed, untyped, and forward-referenced consts all
resolve identically.
- Both dim resolvers now share `program_index.moduleConstInt`, so the stateful
body-lowering path and the stateless registration path cannot diverge.
- `resolveArrayLen` returns `?u32`; `resolveCompound` yields `.unresolved` on
null instead of a 0-length array. The stateful path emits a diagnostic; the
alias-registration path surfaces an unresolved alias as a clean compile error
that aborts the build. The Vector lane-count `else => 0` is fixed the same way.
Regressions: examples/0143 (typed-const dim direct + via alias for s64/string/
struct, forward-ref alias, nested) and examples/1129 (an unresolvable computed
dim halts with a clean diagnostic + non-zero exit). Both fail on the pre-fix
compiler (garbage/segfault; warning+exit0) and pass after.
Makes the F0.4 fixes exhaustive across every resolution / nesting path.
0083 — named-const array dimension, stateless paths. Attempt 1 fixed the
stateful resolver (direct local decls, struct fields, params, returns) but the
binding-free registration-time resolver (`type_bridge`, used for type aliases
`Arr :: [N]T` and inline union/enum field types) still resolved a named dim with
a silent `else 0`, so `Arr :: [N]s64; a : Arr` and `union { a: [N]s64 }` were
still miscompiled (garbage / bus error). Thread the module-global const table
(`ProgramIndex.module_const_map`) into `type_bridge` alongside the alias map, so
`StatelessInner.resolveArrayLen` resolves a named module-const dim to the same
length everywhere. The remaining unresolvable case (a computed/comptime dim on
the binding-free path, which the stateful path hard-errors) now bails LOUDLY
instead of fabricating a 0 length.
0085 — nested slice-literal elements. `lowerArrayLiteral` lowered each element
with the element type as target but appended the raw value. A nested `.[...]`
element at a slice element type (`[][]s64`) still lowers to an aggregate array
`[N]T`, so the outer aggregate held raw arrays where slice {ptr,len} headers
were expected — indexing the inner slice read a garbage pointer and segfaulted.
After lowering each element, coerce a same-element array to the slice element
type via the existing `array_to_slice` op. The coercion recurses with the
nesting, so `[][]T` and deeper materialize at every level — local-bound AND
direct-call-argument forms.
Regressions (fail-before/pass-after demonstrated on the pre-fix compiler):
examples/0140-types-named-const-array-dim.sx — extended with type-alias,
nested [N][M]T, and union-field named dims (s64 / string / struct elems)
examples/0142-types-nested-slice-literal-elements.sx — [][]s64 + [][]string,
local-bound vs direct-arg
src/ir/type_bridge.test.zig — named-const dim resolves to literal length
Gate: zig build, zig build test, bash tests/run_examples.sh (388 passed).
Issues 0083 and 0085 marked RESOLVED.
Two silent-miscompile codegen fixes:
0083 — named-const array dimension. `TypeResolver.resolveCompound`'s array
arm resolved the dimension with `if int_literal ... else 0`, so a named const
(`N :: 16; [N]T`) hit the silent `else 0`: the array became 0-length / 0-byte
and element access ran out of bounds (garbage for scalars, bus error for
slice/pointer/struct elements). The arm now delegates the dimension to
`inner.resolveArrayLen` (symmetric with `inner.resolveInner` for the element).
The stateful `Lowering.resolveArrayLen` evaluates it as a compile-time integer
across the comptime-constant / generic-value / module-global const tables and
emits a diagnostic — no fabricated length — when it isn't one.
0084 — `.[...]` literal passed directly as a call arg. `lowerArrayLiteral`
always yields an aggregate array value; the array→slice conversion is the
caller's job. The local-bound var-decl path did it, but the call-arg coercion
path had no array→slice arm, so `classify([N]T, []T)` returned `.none` and the
raw array was passed where a slice was expected (callee read its {ptr,len}
header off the wrong bytes → 0 / garbage / segfault). `classify` now returns a
new `.array_to_slice` plan for same-element `[N]T → []T`, and `coerceToType`
emits the existing `array_to_slice` op — identical to the local-bound path.
Regressions (fail-before/pass-after demonstrated on the pre-fix compiler):
examples/0140-types-named-const-array-dim.sx (s64 + string + struct elems)
examples/0141-types-slice-literal-direct-call-arg.sx (string + []s64)
Gate: zig build, zig build test, bash tests/run_examples.sh (387 passed).
Issues 0083 and 0084 marked RESOLVED.
