llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Matheus Izvekov (mizvekov) <details> <summary>Changes</summary> In deduction, when comparing template arguments of value kind, we should check if the value matches. Values of different types can still match. For example, `short(0)` matches `int(0)`. Values of nullptr kind always match each other, since there is only one such possible value. Similarly to integrals, the type does not matter. --- Full diff: https://github.com/llvm/llvm-project/pull/124498.diff 3 Files Affected: - (modified) clang/docs/ReleaseNotes.rst (+1) - (modified) clang/lib/Sema/SemaTemplateDeduction.cpp (+4-3) - (modified) clang/test/SemaTemplate/cwg2398.cpp (-4) ``````````diff diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 27574924a14a92..0556879251f89d 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -996,6 +996,7 @@ Bug Fixes to C++ Support - Fix template argument checking so that converted template arguments are converted again. This fixes some issues with partial ordering involving template template parameters with non-type template parameters. +- Fix nondeduced mismatch with nullptr template arguments. Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp index 2b96692727a7c8..1e1fce10e7c017 100644 --- a/clang/lib/Sema/SemaTemplateDeduction.cpp +++ b/clang/lib/Sema/SemaTemplateDeduction.cpp @@ -2541,10 +2541,9 @@ DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams, return TemplateDeductionResult::NonDeducedMismatch; case TemplateArgument::NullPtr: - if (A.getKind() == TemplateArgument::NullPtr && - S.Context.hasSameType(P.getNullPtrType(), A.getNullPtrType())) + // 'nullptr' has only one possible value, so it always matches. + if (A.getKind() == TemplateArgument::NullPtr) return TemplateDeductionResult::Success; - Info.FirstArg = P; Info.SecondArg = A; return TemplateDeductionResult::NonDeducedMismatch; @@ -2559,6 +2558,8 @@ DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams, return TemplateDeductionResult::NonDeducedMismatch; case TemplateArgument::StructuralValue: + // FIXME: structural equality will also compare types, + // but they should match iff they have the same value. if (A.getKind() == TemplateArgument::StructuralValue && A.structurallyEquals(P)) return TemplateDeductionResult::Success; diff --git a/clang/test/SemaTemplate/cwg2398.cpp b/clang/test/SemaTemplate/cwg2398.cpp index 137b94ba2641de..dccb17c48d3256 100644 --- a/clang/test/SemaTemplate/cwg2398.cpp +++ b/clang/test/SemaTemplate/cwg2398.cpp @@ -697,15 +697,11 @@ namespace nttp_partial_order { template void f<B>(B<&A::m>); } // namespace t5 namespace t6 { - // FIXME: This should pick the second overload. struct A {}; using nullptr_t = decltype(nullptr); template<template<nullptr_t> class TT2> void f(TT2<nullptr>); - // new-note@-1 {{here}} template<template<A*> class TT1> void f(TT1<nullptr>) {} - // new-note@-1 {{here}} template<A*> struct B {}; template void f<B>(B<nullptr>); - // new-error@-1 {{ambiguous}} } // namespace t6 } // namespace nttp_partial_order `````````` </details> https://github.com/llvm/llvm-project/pull/124498 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
