bdd0e96d78
A block's value is now its last statement ONLY when that statement is a trailing expression with no `;`. A trailing `;` discards the value, leaving the block void. This makes value-vs-statement explicit and lets the compiler reject "this block was supposed to produce a value". Compiler: - Parser records `Block.produces_value` (last stmt is a no-`;` trailing expression) + `Block.discarded_semi` (the `;` that discarded a value), via `expectSemicolonAfter`. A trailing expression before `}` may now omit its `;` (previously a parse error). Match-arm and else-arm bodies are built value-producing regardless of the arm `;` (arms are exempt — the `;` is an arm terminator). - Lowering: `lowerBlockValue` / the block-expr path / `inferExprType` respect `produces_value`. A value-position block that discards its value is a hard error (`lowerValueBody` for function bodies; the value-context `.block` path for if/else branches, `catch` bodies, value bindings, match arms). Pure-failable `-> !` bodies (value rides the error channel) and a value-if whose branches are void are handled without false errors. - `defer`/`onfail` cleanup bodies lower as statements (void), so a trailing `;` there is fine. Migration (behavior-preserving — output unchanged): - stdlib + ~210 examples: dropped the trailing `;` on value-position last expressions. `format` now ends with an explicit `#insert "return result;"` (it relied on `#insert`-as-block-value, which `;` discards). - Two `main :: () -> s32` examples that relied on the old silent default-return got an explicit trailing `0`. - Rejection snapshots 0412 / 1013 regenerated (their quoted source lines lost a `;`); the diagnostics themselves are unchanged. Docs/tests: specs.md "Block values" section; examples 0040 (rules) + 0041 (rejection); 3 parser unit tests. Filed issue 0066 (pre-existing match-arm negated-literal phi-width quirk, surfaced not caused here). Gates: zig build, zig build test, run_examples.sh -> 343 passed, cross_compile.sh -> 7 passed (also refreshed its stale example names).
50 lines
2.1 KiB
Plaintext
50 lines
2.1 KiB
Plaintext
// Phase 0 baseline (PLAN-FFI.md step 0.4): focused FP-aggregate (HFA)
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// FFI test. All-float / all-double aggregates of ≤4 fields stay as
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// struct values in LLVM and pass through the float register file
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// (AAPCS64 v0..v3, SysV AMD64 xmm0..xmm7). Distinct from the int
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// register-coercion paths (i64 / [2 x i64]).
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//
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// FQuad — 16 B, four f32 (same slot as ffi-02's Vec4f)
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// DQuad — 32 B, four f64 (UIEdgeInsets-shape HFA — the
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// f32-vs-f64 landmine from this session)
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//
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// Already nominally covered by ffi-02's Vec4f, but pinning it as a
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// focused single-file test means a future ABI rule change that
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// breaks the FP path fails *this* test directly without a noisy
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// drag-in from the multi-shape baseline.
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#import "modules/std.sx";
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#import c {
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#source "1212-ffi-04-fp-struct.c";
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};
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FQuad :: struct { a: f32; b: f32; c: f32; d: f32; }
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DQuad :: struct { a: f64; b: f64; c: f64; d: f64; }
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ffi_fquad_make :: (a: f32, b: f32, c: f32, d: f32) -> FQuad #foreign;
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ffi_fquad_reverse :: (v: FQuad) -> FQuad #foreign;
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ffi_fquad_sum :: (v: FQuad) -> f32 #foreign;
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ffi_dquad_make :: (a: f64, b: f64, c: f64, d: f64) -> DQuad #foreign;
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ffi_dquad_reverse :: (v: DQuad) -> DQuad #foreign;
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ffi_dquad_sum :: (v: DQuad) -> f64 #foreign;
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main :: () -> s32 {
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// ── FQuad (16 B, 4×f32 HFA) ────────────────────────────────────
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f := ffi_fquad_make(1.0, 2.0, 3.0, 4.0);
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print("fquad make = ({}, {}, {}, {})\n", f.a, f.b, f.c, f.d);
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g := ffi_fquad_reverse(f);
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print("fquad rev = ({}, {}, {}, {})\n", g.a, g.b, g.c, g.d);
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print("fquad sum = {}\n", ffi_fquad_sum(f));
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// ── DQuad (32 B, 4×f64 HFA — UIEdgeInsets-shape) ──────────────
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d := ffi_dquad_make(1.5, 2.5, 3.5, 4.5);
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print("dquad make = ({}, {}, {}, {})\n", d.a, d.b, d.c, d.d);
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e := ffi_dquad_reverse(d);
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print("dquad rev = ({}, {}, {}, {})\n", e.a, e.b, e.c, e.d);
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print("dquad sum = {}\n", ffi_dquad_sum(d));
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0
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}
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