8a875d354c
Using a bare pack name where a runtime value is required was silent garbage (f(xs)/return xs produced a stray pointer). Now a clear, context-tailored compile error: isPackName + diagPackAsValue, caught at lowerVarDecl (storage), lowerReturn (return), lowerFor (iterate), and an identifier-arm catch-all for call/other. Storage binds a placeholder so there is no cascade error. Suggestions point at WORKING fixes -- materialize (..xs), or declare the slice form ..xs: []P for runtime use. The plan category-B "spread ..xs" is broken (spreading a comptime pack into a []Any param crashes the LLVM verifier; filed issue 0053), so the diagnostics steer to the slice-of-protocol variadic instead. Repurposed examples/162-pack-bare-args.sx (was an aspirational bare-$args->[]Any auto-materialise, contradicting Decision 1) into the slice-form forward (..args: []Any). examples/203 is the four-category negative test. specs.md "Pack as value" updated. 238 examples + unit green.
1.8 KiB
Symptom
Spreading a comptime pack ..$args into a []Any parameter — f(..args) where
f takes items: []Any — fails LLVM verification:
LLVM verification failed: Incorrect number of arguments passed to called function!
%call = call i64 @log_count(ptr %0, { ptr, i64 }, { ptr, i64 }, double ...)
The spread passes the pack's N elements as N separate positional args instead of
materialising a single []Any slice for the one items parameter.
Reproduction
#import "modules/std.sx";
log_count :: (items: []Any) -> s64 { return items.len; }
forward :: (..$args) -> s64 { return log_count(..args); }
main :: () -> s32 { print("{}\n", forward(1, "hi", 2.5)); return 0; }
Expected: 3 (the pack spreads into the []Any slice, like calling
log_count(1, "hi", 2.5) against a []Any variadic would).
Workaround / current advice
Declare the forwarder as the slice variadic instead of a pack — then it's
already a runtime []Any and forwards directly (no spread needed):
forward :: (..args: []Any) -> s64 { return log_count(args); } // works -> 3
This is what examples/162-pack-bare-args.sx now demonstrates, and what the
Step 2.7 pack-as-value diagnostic recommends (declare ..xs: []P for runtime
use rather than spreading a pack).
Suspected area
The call-arg spread lowering (packSpreadRefs / lowerVariadicArgs /
packVariadicCallArgs interaction in src/ir/lower.zig):
when the spread source is a comptime pack and the callee parameter is a single
[]Any (not itself variadic/pack), the spread must collect the pack
elements into one []Any slice arg, not splat them as separate positional args.
Compare the working path where the callee is itself a []Any variadic.
Verification
The reproduction above should print 3 and pass sx ir LLVM verification.