Repro found while writing PLAN-FFI step 0.10.
In a single file:
__stdinp : *void #foreign;
stdinp_addr :: () -> u64 { xx @__stdinp; }
main :: () -> s32 {
a : u64 = xx @__stdinp; // a = real symbol address
b := stdinp_addr(); // b = 0
...
}
The emitted IR for the helper is `ret i64 undef`, suggesting the
`address_of(identifier=__stdinp)` branch in lower.zig (~line 1719)
doesn't see `__stdinp` in `global_names` at the moment the helper's
body is being lowered — even though the same lookup succeeds inside
main's body in the same compilation unit.
Likely cause: lazy-body lowering ordering vs. the pass that
registers extern global decls into `global_names`. Worth verifying
which before fixing — could also be per-function scoping of the
map. Phase 1 of the FFI plan doesn't depend on this, so it stays
filed as an open issue and gets addressed when convenient (or when
sx-side `extern` cross-file globals from issue-0030 land and need
the same lookup to work everywhere).
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