Files
sx/examples/0506-packs-pack-if-return.sx
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

40 lines
1.4 KiB
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// Variadic heterogeneous type packs — control-flow follow-up to
// issue-0045 fix (commit 9e78790).
//
// issue-0045's fix routes inline-comptime-body `return X;` into a
// result slot so the caller's basic block isn't terminated
// mid-flight. But the fix sets `block_terminated = true` after
// the inline return — which leaks PAST the enclosing `if`'s
// merge block. When the body shape is
// if cond { return X; }
// return Y;
// only the then-branch's `return X;` runs; `block_terminated`
// stays true in the merge block, so `lowerBlockValue`'s loop
// exits before the trailing `return Y;` lowers. The trailing
// return never stores into the slot — for the false-condition
// path the load reads uninitialised stack memory.
//
// Pack-fn `..$args` is the shortest repro because `args.len`
// gives a comptime-feeling test for the condition. The bug is
// actually shape-agnostic — any comptime body with `if cond
// { return X; }; return Y;` regresses the same way.
//
// `maybe()` with zero call-args takes the false branch and
// should fall through to `return -1;`. Today it loads garbage
// from the uninitialised slot.
#import "modules/std.sx";
maybe :: (..$args) -> i64 {
if args.len > 0 {
return 42;
}
return -1;
}
main :: () -> i32 {
print("{}\n", maybe()); // expect -1
print("{}\n", maybe(99)); // expect 42
return 0;
}