1f9f944ca1
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.
56 lines
2.6 KiB
Markdown
56 lines
2.6 KiB
Markdown
# 0085 — nested slice literal elements are stored as raw arrays
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> **RESOLVED.** Root cause: `Lowering.lowerArrayLiteral` lowered each element with
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> the element type as `target_type` but appended the returned value directly. For
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> a nested `.[...]` element whose expected element type is a slice (`[]T`), the
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> inner literal still lowers to an aggregate ARRAY `[N]T` — so the outer aggregate
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> (typed array-of-`[]T`) held raw arrays where slice {ptr,len} headers were
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> expected; indexing the inner slice read a garbage pointer and segfaulted. Fix:
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> after lowering each element, when the element type is a slice and the lowered
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> value is a same-element array, coerce it via the existing `array_to_slice` op
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> (materialize backing storage + build the header) — identical to the whole-
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> literal coercion the var-decl / call-arg paths already run. The coercion
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> recurses with the nesting, so `[][]T` and deeper materialize at every level.
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> Files: `src/ir/lower.zig` (`lowerArrayLiteral`). Regression:
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> `examples/0142-types-nested-slice-literal-elements.sx` (`[][]s64` + `[][]string`,
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> local-bound AND direct-call-argument forms).
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## Symptom
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Nested array/slice literals such as `.[.[1, 2], .[3, 4]]` miscompile when the
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expected element type is a slice (`[][]s64`). Observed: both the local-bound and
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direct-call forms segfault while indexing the inner slice. Expected: both forms
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materialize each inner `[N]T` literal as a `[]T` slice and print the same value.
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## Reproduction
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```sx
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#import "modules/std.sx";
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sum_nested :: (xss: [][]s64) -> s64 {
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return xss[0][1] + xss[1][0];
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}
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main :: () {
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local : [][]s64 = .[.[1, 2], .[3, 4]];
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print("local={}\n", sum_nested(local));
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print("direct={}\n", sum_nested(.[.[1, 2], .[3, 4]]));
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}
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```
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Observed on `flow/sx-foundation/F0.4`: segfault at address `0x9` before either
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line prints. Expected output:
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```text
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local=5
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direct=5
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```
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## Investigation prompt
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Fix nested slice literal materialization. The likely area is
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`src/ir/lower.zig` in `Lowering.lowerArrayLiteral`: the outer literal can know
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its expected element type is `[]T`, and the loop sets `self.target_type =
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elem_ty` while lowering each inner literal, but it appends the returned value
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directly. For an inner `.[...]`, that returned value is still an array aggregate
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`[N]T`, not the target `[]T` slice. Add per-element coercion/materialization
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after lowering each element, using the element source type and expected
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`elem_ty` (the existing `array_to_slice` coercion should be reused). Verify the
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repro prints `local=5` and `direct=5`, then run `zig build && zig build test &&
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bash tests/run_examples.sh`.
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