Files
sx/examples/1323-ffi-objc-arc-00b-multi-instance.sx
agra bdd0e96d78 feat(lang): block value requires no trailing ; (Rust-style)
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).
2026-06-02 09:23:50 +03:00

75 lines
2.5 KiB
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// ffi-objc-arc-00b — multi-instance allocator threading.
//
// Verifies that EACH sx-defined-class instance captures its own
// allocator and round-trips through it. Catches bugs where:
// - the captured allocator is shared across instances (one global
// slot instead of per-instance).
// - alloc captures the wrong allocator on the 2nd+ instance.
// - dealloc reads garbage if state[0] is overwritten between
// instances.
//
// Three instances → three alloc events → three dealloc events. The
// tracker observes exactly +3 / +3 deltas.
#import "modules/std.sx";
#import "modules/allocators.sx";
#import "modules/std/objc.sx";
#import "modules/compiler.sx";
SxMultiProbe :: #objc_class("SxMultiProbe") {
#extends NSObject;
a: s32;
b: s32;
alloc :: () -> *SxMultiProbe;
}
main :: () -> s32 {
inline if OS == .macos {
gpa := GPA.init();
tracker := TrackingAllocator.init(xx gpa);
push Context.{ allocator = xx tracker, data = null } {
alloc_before := tracker.alloc_count;
dealloc_before := tracker.dealloc_count;
f1 := SxMultiProbe.alloc();
f2 := SxMultiProbe.alloc();
f3 := SxMultiProbe.alloc();
alloc_after_three := tracker.alloc_count - alloc_before;
f1.release();
f2.release();
f3.release();
alloc_delta := tracker.alloc_count - alloc_before;
dealloc_delta := tracker.dealloc_count - dealloc_before;
// alloc_delta MAY include extras from autorelease/etc. but
// each SxMultiProbe.alloc contributes at least 1. Check the
// BALANCE: every alloc paired with a dealloc.
if dealloc_delta != alloc_delta {
print("FAIL: alloc/dealloc unbalanced; alloc={} dealloc={}\n",
alloc_delta, dealloc_delta);
return 1;
}
if alloc_after_three < 3 {
print("FAIL: 3 SxMultiProbe.alloc()s should produce >= 3 tracker allocs; saw {}\n",
alloc_after_three);
return 1;
}
if dealloc_delta < 3 {
print("FAIL: 3 release()s should produce >= 3 tracker deallocs; saw {}\n",
dealloc_delta);
return 1;
}
}
print("multi-instance round-trip: ok\n");
}
inline if OS != .macos {
print("skipped (not macos)\n");
}
0
}