lab/sx

Files

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

2.4 KiB

Raw Blame History

0030 — `extern G : T;` cross-file sx global declarations (feature request)

Status: OPEN feature request (not a bug). Relocated from the old examples/issue-0030.sx placeholder during the test-layout migration. Repro: issues/0030-extern-global-declarations.sx (currently a parse error — the syntax doesn't exist yet).

Symptom / request

Support an extern G : T; top-level form so a global defined in one sx source file can be referenced from another without threading it through parameters — mirroring how #foreign function declarations work (declared in one place, defined elsewhere, resolved at link time).

// game/main.sx
g_metal_gpu : *MetalGPU = null;

// game/chess/pieces.sx
extern g_metal_gpu : *MetalGPU;          // ← parse error today

load :: (self: *ChessPieces, path: [:0]u8) {
    inline if OS == .ios {
        tex := g_metal_gpu.create_texture(w, h, .rgba8, xx pixels);
    }
}

Today pieces.load takes has_gpu: bool, gpu: GPU params and main.sx threads them through; cross-file extern globals would drop that ceremony. Distinct from the existing name : T #foreign; form (an external C data symbol from libsystem etc. — see examples/1205-ffi-foreign-global.sx); this request is for sx-defined globals shared across sx modules.

Reproduction

issues/0030-extern-global-declarations.sx:

#import "modules/std.sx";
extern g_x : *void;          // want: a reference to a global defined elsewhere
main :: () -> i32 { 0; }

./zig-out/bin/sx run … → error: expected '::', ':=', or ':' after identifier (the extern keyword/form is unparsed).

Implementation sketch

parser — surface syntax for extern G : T;. Must not clash with G :: T; (type alias), G : T = ---; (uninitialized global), G : T; (typed global). Reject extern G : T = expr; (an extern can't carry an initializer).
src/ir/lower.zig — record an extern-global stub that resolves at module-link time.
src/ir/emit_llvm.zig — emit an external LLVM global (no storage, just a reference). Globals already have first-class IR addresses; this adds an "extern" flag meaning "emit a reference, not storage."

Caveat

Encourages process-global state. Steer callers toward explicit parameter passing where reasonable; reserve for genuine process singletons (active GPU, active platform) where threading through every call site is more noise than signal.

2.4 KiB Raw Blame History

0030 — extern G : T; cross-file sx global declarations (feature request)