Files
sx/issues/0093-global-raw-value-numeric-limit-shadow.md
agra d8076b9333 lang: rename signed integer types sN -> iN
Surface rename of the signed integer family: s1..s64 become i1..i64
(u1..u64, usize, isize unchanged). 'string' keeps the s-prefix arm in
name classification; width parsing moves to the i-prefix arm next to
isize.

Internal TypeId tags follow the surface (.s8/.s16/.s32/.s64 ->
.i8/.i16/.i32/.i64), as do mono-key mangle fragments (ptr_i64,
tu_i64_bool) and all display/diagnostic formatting (i{d}).

Migrated in the same sweep: stdlib + examples + issue repros + FFI C
companions (shared symbol names like ffi_id_i64), expected
stdout/stderr/ir snapshots, specs.md, readme.md, CLAUDE.md/AGENTS.md,
implementation_plan.md, docs/, issue writeups. Vendored stb_image and
historical flow state left untouched.

zig build test: 426/426; examples suite: 595/595.
2026-06-12 09:31:53 +03:00

85 lines
4.2 KiB
Markdown

> **RESOLVED** (NL.2 attempt 4). Root cause: the issue-0092 fix guarded the
> numeric-limit intercept against value shadowing using ONLY lexical
> `Scope.lookup`. But the ordinary identifier field-access path resolves a
> value through THREE sources (`expr_typer.zig` `.identifier` arm): lexical
> `scope` → program `global_names` → module value constants
> `module_const_map`. A backtick raw identifier bound at MODULE scope
> (`` `f64 := Box.{…} ``, a global, or `` `f64 :: Box.{…} ``, a module const)
> is registered in `global_names` / `module_const_map`, NOT in `Scope`, so the
> scope-only guard missed it and the intercept still folded `` `f64.epsilon ``
> to the numeric limit — the same silent-wrong-value bug as 0092, one source
> deeper. The module-const variant has the same root cause and is covered by
> the same fix (no separate issue).
>
> Fix (close ALL THREE value-binding sources in one pass): a single shared
> helper `Lowering.identifierBindsValue(name)` returns true when `name`
> resolves through `scope.lookup` OR `program_index.global_names` OR
> `program_index.module_const_map`. Used in BOTH resolvers so they cannot
> desync (issue-0083 two-resolver class):
> - `src/ir/lower.zig` — `lowerNumericLimit`: defer to ordinary field lowering
> (return null) when an `.identifier` receiver `identifierBindsValue`.
> - `src/ir/expr_typer.zig` — numeric-limit inference arm: the `shadowed`
> check now calls the same helper.
>
> A bare `f64.epsilon` / `i32.max` (a `.type_expr` receiver, never an
> `.identifier`) still folds, even when a global or module-const raw value of
> the same spelling exists — the bare receiver is never value-shadowed.
> Float-only-on-int and non-numeric-receiver errors are unchanged.
>
> Regression: `examples/0161-types-numeric-limit-value-shadow.sx` now exercises
> all three binding kinds — a GLOBAL `` `f32 ``, a MODULE-CONST `` `i16 ``, and
> LOCAL `` `f64 ``/`` `i32 ``/`` `u8 `` — each reading its field while the bare
> spelling still folds. Unit test `src/ir/expr_typer.test.zig` pins the global
> + module-const sources. NL.1 (`examples/0148`) / NL.2 (`examples/0159`,
> `examples/0160`) unregressed.
# 0093 — numeric-limit intercept hijacks global raw reserved-spelled value receivers
## Symptom
Field access on a **global** raw reserved-spelled value binding is interpreted as
a builtin type numeric-limit access instead of an ordinary value field access.
Observed: the repro prints `0.000000 2147483647` (`f64.epsilon` /
`i32.max`). Expected: it prints `12 78` from the `Box` fields.
## Reproduction
```sx
#import "modules/std.sx";
Box :: struct { epsilon: i64; max: i64; }
`f64 := Box.{ epsilon = 12, max = 34 };
`i32 := Box.{ epsilon = 56, max = 78 };
main :: () -> i32 {
print("{} {}\n", `f64.epsilon, `i32.max);
return 0;
}
```
## Investigation prompt
Investigate issue 0093: the issue-0092 value-binding precedence fix covers
lexical locals but misses global raw value bindings. In `src/ir/lower.zig`, start
at `Lowering.lowerNumericLimit` and the new issue-0092 guard around
`Scope.lookup`. That guard returns `null` for a shadowing local, but global raw
bindings are registered in `ProgramIndex.global_names` (and module constants in
`ProgramIndex.module_const_map`), not in `Scope`, so an `.identifier` receiver
whose text is `f64` / `i32` still folds to a numeric limit before ordinary
global field lowering can read the value. Mirror the same rule in
`src/ir/expr_typer.zig` so inferred types match lowering.
Likely fix: for `.identifier` numeric-limit receivers, prefer any in-scope value
binding source over the builtin-type fold: lexical `Scope.lookup`, global values
(`program_index.global_names`), and module value constants where applicable.
Keep `.type_expr` receivers folding as type receivers, so bare `f64.epsilon` and
`i32.max` still fold even when a raw global value of the same spelling exists.
Verification: pin the repro above as a regression. It should print `12 78`.
Also verify the existing numeric-limit examples still pass:
`examples/0148-types-int-numeric-limits.sx`,
`examples/0159-types-float-numeric-limits.sx`,
`examples/0160-types-float-numeric-limits-errors.sx`, and
`examples/0161-types-numeric-limit-value-shadow.sx`.