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[Clang] Do not try to transform invalid bindings #125658

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Merged
merged 1 commit into from
Feb 19, 2025
Merged

[Clang] Do not try to transform invalid bindings #125658

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2 changes: 1 addition & 1 deletion clang/lib/Sema/TreeTransform.h
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Original file line number Diff line number Diff line change
Expand Up @@ -12716,7 +12716,7 @@ TreeTransform<Derived>::TransformDeclRefExpr(DeclRefExpr *E) {
ValueDecl *ND
= cast_or_null<ValueDecl>(getDerived().TransformDecl(E->getLocation(),
E->getDecl()));
if (!ND)
if (!ND || ND->isInvalidDecl())
return ExprError();

NamedDecl *Found = ND;
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15 changes: 15 additions & 0 deletions clang/test/SemaCXX/cxx2c-binding-pack.cpp
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Expand Up @@ -218,3 +218,18 @@ auto X = [] <typename = void> () {
static_assert(sizeof...(pack3) == 5);
};
} // namespace

namespace GH125165 {

template <typename = void>
auto f(auto t) {
const auto& [...pack] = t;
// expected-error@-1 {{cannot decompose non-class, non-array type 'char const'}}
(pack, ...);
};

void g() {
f('x'); // expected-note {{in instantiation}}
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Interesting, should this work: https://godbolt.org/z/dKcaa3jY4

We should also try other arguments types beside char like int, float etc

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@ricejasonf ricejasonf Feb 6, 2025 •
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That happens to work because the pack can be empty. In clang-19 it seems to still allow decomposition. https://godbolt.org/z/zMrqTYE8c

(I am not saying that it should though.... maybe because it is empty?)

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Maybe: https://godbolt.org/z/Ejf8Mj5jj

}

}