d8076b9333
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.
77 lines
3.2 KiB
Markdown
77 lines
3.2 KiB
Markdown
# 0101 — postfix `!` chained with `.field` miscompiles
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**RESOLVED.** A postfix optional force-unwrap chained directly with a member
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access — `opt!.field` — read garbage instead of the field, while the
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bind-first form (`v := opt!; v.field`) was correct. Sibling chains shared the
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bug: `opt!.method()` failed to resolve the method at all (`error: unresolved
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'<method>'`), and `opt!.a.b` / `opt![i]` were affected the same way.
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**Symptom** — observed vs expected:
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```sx
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#import "modules/std.sx";
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S :: struct { id: string; n: i64; }
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mk :: () -> ?S { return S.{ id = "hello", n = 42 }; }
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main :: () {
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print("chained: {}\n", mk()!.id); // observed: garbage (e.g. 8362783136)
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v := mk()!; print("bind: {}\n", v.id); // observed: "hello" (correct)
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}
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```
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Expected: `mk()!.id` prints `hello` (same as the bind-first form).
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**Root cause** (`src/ir/expr_typer.zig`, `ExprTyper.inferType`): the AST-level
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type-inference switch had **no `.force_unwrap` arm**, so `mk()!` typed as
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`.unresolved` (the `else` fallback). `lowerForceUnwrap` lowers the unwrap to a
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correctly-typed value, so the *bind* form works — `v := mk()!` stores that
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typed Ref into a slot and `v.field` reads it back. But the *chained* form never
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materializes a slot: `lowerFieldAccess` re-derives the receiver type via
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`inferExprType(fa.object)` (= `inferExprType(mk()!)`), got `.unresolved`, and
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the struct-field lookup on `.unresolved` failed — `mk()!.id` was typed
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`.unresolved`/`i64` and its value emitted as `undef` (the print monomorphized
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`pack_i64` with `i64 undef`, surfacing as a stale stack address). The method
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chain failed for the same reason: receiver typing returned `.unresolved`, so
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method resolution found nothing.
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**Fix** (`src/ir/expr_typer.zig:92`): add a `.force_unwrap` arm to
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`ExprTyper.inferType` that resolves the operand's optional child type (mirrors
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`lowerForceUnwrap`'s `resolveOptionalInner`):
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```zig
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.force_unwrap => |fu| blk: {
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const opt_ty = self.l.inferExprType(fu.operand);
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if (!opt_ty.isBuiltin()) {
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const info = self.l.module.types.get(opt_ty);
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if (info == .optional) break :blk info.optional.child;
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}
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break :blk .unresolved;
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},
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```
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This is the single root cause for every chained form — field, nested field,
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method call, and index all route their receiver type through `inferExprType`.
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One arm fixes all of them.
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**Reproduction** (standalone, std-only):
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```sx
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#import "modules/std.sx";
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Inner :: struct { tag: string; k: i64; }
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S :: struct {
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id: string; n: i64; inner: Inner;
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greet :: (self: *S) -> string { return self.id; }
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}
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mk :: () -> ?S { return S.{ id = "hello", n = 42, inner = Inner.{ tag = "deep", k = 7 } }; }
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main :: () {
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print("{}\n", mk()!.id); // pre-fix: garbage; post-fix: hello
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print("{}\n", mk()!.n); // pre-fix: garbage; post-fix: 42
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print("{}\n", mk()!.greet()); // pre-fix: error unresolved 'greet'; post-fix: hello
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print("{}\n", mk()!.inner.tag); // post-fix: deep
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}
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```
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**Regression**: `examples/0905-optionals-unwrap-field-chain.sx` exercises
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`opt!.field` (string + int field, chained vs bind-first), `opt!.method()`
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(pointer + value receiver), nested `opt!.a.b`, and `opt![i]`. Garbage / compile
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error on pre-fix code; all correct after.
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