C: va_arg of any non-int type -> "invalid symbol in lea"

• Type: bug (Track C — C frontend desugar in cparser.inc; the failing guard is shared ir.inc).
• Status: done
• Found: 2026-06-26 writing the lib/crtl printf engine. Blocks the entire printf family: every %s (char*), %x/%u (unsigned), %p (void*) and %ld (long) needs a non-int va_arg.
• Closed: 2026-06-27

Symptom

va_arg(ap, T) compiles only for T == int. Every other scalar type fails at compile time:

$ pascal26 va.c out
pascal26:61: error: invalid symbol in lea ()

Reproduced for unsigned int, long, char *, void *, unsigned long. Minimal repro:

#include <stdarg.h>
static long f(int n, ...) {
  va_list ap; va_start(ap, n);
  long x = va_arg(ap, long);        /* char* / void* / unsigned all fail too */
  va_end(ap);
  return x;
}
int main(void){ return (int)f(1, 5); }

va_arg(ap, int) is fine (test/cvarargs_int_b49.c passes).

Root cause (narrowed)

cparser.inc (~243) desugars __builtin_va_arg(ap, T) to *(T*)__pxx_va_arg_gp(&ap) by building AN_DEREF directly over the helper AN_CALL, tagging ASTTk[deref] := T:

node := AllocNode(AN_DEREF); ASTLeft[node] := callNode; ASTTk[node] := Ord(vt);

For T = int this lowers to a clean IR_LOAD_MEM. For an 8-byte / non-int T the value-path lowering emits an IR_LEA whose operand is the call node (not a symbol), tripping the verifier guard at ir.inc:297 Error('invalid symbol in lea').

The equivalent explicit cast compiles and runs fine:

extern void *get(void);
int main(void){ return (int)(*(long*)get()); }   /* ok */

The difference: the explicit form wraps the call in an AN_PTR_CAST (*(long*) ...), the va_arg desugar omits it. Likely fix: wrap callNode in an AN_PTR_CAST (to T*/tyPointer) before the AN_DEREF, matching the working *(T*)call() shape — a Track C change in cparser.inc. (If the real defect is the value-path AN_DEREF LEA for a non-int type over a non-symbol operand, that is shared ir.inc and belongs to Track A — confirm which during the fix.)

Acceptance

va_arg(ap, T) works for int, unsigned, long, and any pointer type; lib/crtl/src/stdio.c snprintf("%s/%x/%p", ...) renders correctly.

Resolution

• 2026-06-27 audit — DONE / no longer reproducible. Solved as a side effect of later Lua/stdio varargs work. Current compiler/pascal26 compiles and runs the old va_arg(ap, long) repro, returning 5, and a combined probe covering unsigned int, char *, and void * returns 42. No invalid symbol in lea error remains.