Hojun-Cho 993da52333 selfhost+test: nodeisstr handles N_INDEX of [N]str (#34) ...

wwstage's nodeisstr (cgenutil) didn't recognize N_INDEX-of-[N]str.
cgindex emitted only the ptr-half MOVQ when the result was used as
a str arg (call, .len access, str streq), so the .len half read
stack residue. Surfaced by worker-21 during #21 dev — pre-#21
slotsize=24B masked the read-side defect; post-#21 (16B stride)
exposed it. cstage's typed-AST node_isstr handles this naturally;
wwstage's untyped pattern walks the base ident's tnode shape.

Added N_INDEX arm to nodeisstr: walk the indexed base's tnode
through N_TARRAY / N_TSLICE / N_TPTR.lhs, return isstrtype on the
element. Mirrors cgindex's own base-type walk byte-for-byte in
shape so the two now agree on load-shape decisions.

Not covered (separate bugs, separately filed):
- N_UN(TK_STAR) of *str — cgun itself never loads .len into BX.
- tuple `.1` of str — N_TTUPLE path has its own load shape.
- alias-typed base (`type a = [N]str`) — N_TNAME isn't peeled; cgindex
  doesn't peel it either, so agreement holds. Outside #34 scope.

Test 711: 3 new rows — barelet_index_call_arg (streq direct arg),
nested_call_index_arg (f(g(argv[i])) — nested-call recursion),
barelet_index_len_arg (sister regression-pin for cgindex element
stride in bare-let context; pins a different code path that was
already correct post-#21).

The pre-existing wwstage `..findflag(SB)` symbol-mangling bug in
getopttest wwstage build is filed as task #37, not in this commit's
scope.

2026-05-16 11:37:17 +09:00

586 KiB

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