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).
47 lines
1.7 KiB
Plaintext
47 lines
1.7 KiB
Plaintext
// Phase 1 step 1.9 (PLAN-FFI.md): all-double HFA returns through
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// `#objc_call`. 4×f64 = 32 B, stays in v0..v3 on AAPCS64 and
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// xmm0..xmm3 on SysV AMD64 — same shape as UIEdgeInsets / NSRect /
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// CGRect, the f32-vs-f64 landmine that bit us when we first wrote
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// `safeAreaInsets` in uikit.sx.
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//
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// Nominally covered by ffi-objc-call-05's nil-recv NSRect case,
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// but that only checks that zeros come back. Here we install a
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// real IMP that returns specific non-zero values and verify each
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// field comes through the float-register file intact.
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#import "modules/std.sx";
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#import "modules/compiler.sx";
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#import "modules/std/objc.sx";
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UIEdgeInsets :: struct {
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top: f64;
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left: f64;
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bottom: f64;
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right: f64;
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}
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insets_imp :: (self: *void, _cmd: *void) -> UIEdgeInsets callconv(.c) {
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UIEdgeInsets.{ top = 1.5, left = 2.5, bottom = 3.5, right = 4.5 }
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}
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main :: () -> s32 {
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inline if OS == .macos {
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ns_object := objc_getClass("NSObject".ptr);
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my_cls := objc_allocateClassPair(ns_object, "SxInsetsProbe".ptr, 0);
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sel := sel_registerName("safeAreaInsets".ptr);
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// Method type encoding: {UIEdgeInsets=dddd}@: → returns 4×f64,
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// implicit (self: id, _cmd: SEL). `d` = double.
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ok := class_addMethod(my_cls, sel, xx insets_imp, "{UIEdgeInsets=dddd}@:".ptr);
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print("addMethod = {}\n", ok);
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objc_registerClassPair(my_cls);
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instance := class_createInstance(my_cls, 0);
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ins := #objc_call(UIEdgeInsets)(instance, "safeAreaInsets");
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print("insets = ({}, {}, {}, {})\n", ins.top, ins.left, ins.bottom, ins.right);
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}
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inline if OS != .macos {
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print("skipped (not macos)\n");
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}
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0
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}
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