Hojun-Cho
3d79735964
wwstage exprtype's N_CALL fn-value arm peeled ALL pointer levels before the TY_FN gate, so a deref-less `pf(21)` where pf:**fn type-checked and lowered -- then segfaulted at runtime (a silent miscompile). cstage peels exactly one level and loud-rejects (the C6a discipline, check.c:1947). Align wwstage DOWN: peel one level (loop -> if); a remaining non-TY_FN callee hits a loud "calling non-function" reject mirroring cstage's message. Both stages now reject the exotic deref-less `**fn`/`***fn` shape; the legitimate `(*pf)(21)` and one-level deref-less `f(21)` (f:*fn) still compile + run. Multi-level autoderef is a separate deferred FEATURE, not a miscompile to lower (rule 7/10 -- align the richer stage down to the leaner, no value ships). ww-only change (cstage is the correct oracle); a reject emits no asm, so the byte-id baselines and LANGBYTEID floor are unchanged. Pins: cfail test/wcc/data/fnptr_pp_derefless_reject (both stages reject, reddens-on-revert -- the silent miscompile resurfaces if the fix is reverted) + test/lang/fnptr_derefless_call_test (positive guard (*pf)(21)==42 and one-level f(21), value-asserted + byte-id, so the fix does not over-reject the legitimate one-level autoderef).
22 lines
1.1 KiB
Plaintext
22 lines
1.1 KiB
Plaintext
//ww:error "calling non-function"
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// #14: a deref-less call through a pointer-to-pointer-to-fn (`pf(21)` where
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// pf: **fn) is a hard reject in BOTH stages. The #181-cgen path lowers an
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// indirect call by using the callee VALUE as the target, so it autoderefs
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// exactly ONE pointer level — correct for a single `*fn`, but for a `**fn`
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// the value is only the *address of* the fn-ptr, so a deref-less call ships
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// a CALL through that address and segfaults. cstage rejected at one-level
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// peel (cmd/wcc/check.c:1947); wwstage was the SILENT-miscompile side until
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// it was aligned DOWN to the same one-level peel (selfhost/cmd/wcc/check.ww,
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// task #14). Multi-level fn-ptr autoderef is a deferred FEATURE (#181); the
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// legal one-explicit-deref `(*pf)(21)` stays accepted (test/lang/
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// fnptr_derefless_call_test.ww derefless_pp_one_explicit_deref). REVERT
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// MANIFESTATION: revert the wwstage peel loop->if and this case COMPILES
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// again under w6c_ww (the runww ERROR arm runs both stages).
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package main;
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fn add1(x: i32) i32 = { return x + 21; };
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export fn main() i32 = {
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let f: *fn(x: i32) i32 = &add1;
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let pf: **fn(x: i32) i32 = &f;
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return pf(21);
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};
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