Alias template with NTTP crashes if it has an unevaluated generic lambda taking auto...
#105885
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clang:frontend
Language frontend issues, e.g. anything involving "Sema"
confirmed
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crash
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EugeneZelenko
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clang:frontend
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@llvm/issue-subscribers-clang-frontend Author: Mital Ashok (MitalAshok)
https://godbolt.org/z/rzdG81qd7
template<int>
using test = decltype([](auto...) {
}());
static_assert(__is_same(test<0>, void)); |
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Looks like a regression on trunk: https://godbolt.org/z/j79K6z5fz |
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Confirmed #89934 would fix this. |
llvmbot
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Aug 27, 2024
…late decl (llvm#89934) In the last patch llvm#82310, we used template depths to tell if such alias decls contain lambdas, which is wrong because the lambda can also appear as a part of the default argument, and that would make `getTemplateInstantiationArgs` provide extra template arguments in undesired contexts. This leads to issue llvm#89853. Moreover, our approach for llvm#82104 was sadly wrong. We tried to teach `DeduceReturnType` to consider alias template arguments; however, giving these arguments in the context where they should have been substituted in a `TransformCallExpr` call is never correct. This patch addresses such problems by using a `RecursiveASTVisitor` to check if the lambda is contained by an alias `Decl`, as well as twiddling the lambda dependencies - we should also build a dependent lambda expression if the surrounding alias template arguments were dependent. Fixes llvm#89853 Fixes llvm#102760 Fixes llvm#105885 (cherry picked from commit b412ec5)
5c4lar
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Aug 29, 2024
…late decl (llvm#89934) In the last patch llvm#82310, we used template depths to tell if such alias decls contain lambdas, which is wrong because the lambda can also appear as a part of the default argument, and that would make `getTemplateInstantiationArgs` provide extra template arguments in undesired contexts. This leads to issue llvm#89853. Moreover, our approach for llvm#82104 was sadly wrong. We tried to teach `DeduceReturnType` to consider alias template arguments; however, giving these arguments in the context where they should have been substituted in a `TransformCallExpr` call is never correct. This patch addresses such problems by using a `RecursiveASTVisitor` to check if the lambda is contained by an alias `Decl`, as well as twiddling the lambda dependencies - we should also build a dependent lambda expression if the surrounding alias template arguments were dependent. Fixes llvm#89853 Fixes llvm#102760 Fixes llvm#105885
tru
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Sep 1, 2024
…late decl (llvm#89934) In the last patch llvm#82310, we used template depths to tell if such alias decls contain lambdas, which is wrong because the lambda can also appear as a part of the default argument, and that would make `getTemplateInstantiationArgs` provide extra template arguments in undesired contexts. This leads to issue llvm#89853. Moreover, our approach for llvm#82104 was sadly wrong. We tried to teach `DeduceReturnType` to consider alias template arguments; however, giving these arguments in the context where they should have been substituted in a `TransformCallExpr` call is never correct. This patch addresses such problems by using a `RecursiveASTVisitor` to check if the lambda is contained by an alias `Decl`, as well as twiddling the lambda dependencies - we should also build a dependent lambda expression if the surrounding alias template arguments were dependent. Fixes llvm#89853 Fixes llvm#102760 Fixes llvm#105885 (cherry picked from commit b412ec5)
dmpolukhin
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Sep 2, 2024
…late decl (llvm#89934) In the last patch llvm#82310, we used template depths to tell if such alias decls contain lambdas, which is wrong because the lambda can also appear as a part of the default argument, and that would make `getTemplateInstantiationArgs` provide extra template arguments in undesired contexts. This leads to issue llvm#89853. Moreover, our approach for llvm#82104 was sadly wrong. We tried to teach `DeduceReturnType` to consider alias template arguments; however, giving these arguments in the context where they should have been substituted in a `TransformCallExpr` call is never correct. This patch addresses such problems by using a `RecursiveASTVisitor` to check if the lambda is contained by an alias `Decl`, as well as twiddling the lambda dependencies - we should also build a dependent lambda expression if the surrounding alias template arguments were dependent. Fixes llvm#89853 Fixes llvm#102760 Fixes llvm#105885
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https://godbolt.org/z/rzdG81qd7
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