Index: clang/lib/AST/ASTContext.cpp =================================================================== --- clang/lib/AST/ASTContext.cpp +++ clang/lib/AST/ASTContext.cpp @@ -6245,14 +6245,29 @@ auto *TYTCArgs = TYTC->getTemplateArgsAsWritten(); if (TXTCArgs->NumTemplateArgs != TYTCArgs->NumTemplateArgs) return false; - llvm::FoldingSetNodeID XID, YID; - for (auto &ArgLoc : TXTCArgs->arguments()) - ArgLoc.getArgument().Profile(XID, X->getASTContext()); - for (auto &ArgLoc : TYTCArgs->arguments()) - ArgLoc.getArgument().Profile(YID, Y->getASTContext()); - if (XID != YID) - return false; + // We couldn't compare the profiling result for the template + // args here. Consider the following example in different modules: + // + // template <__integer_like _Tp, C<_Tp> Sentinel> + // constexpr _Tp operator()(_Tp &&__t, Sentinel &&last) const { + // return __t; + // } + // + // When we compare the profiling result for `C<_Tp>` in different + // modules, it will compare the type of `_Tp` in different modules. + // However, the type of `_Tp` in different modules refer to different + // types here naturally. So we couldn't compare the profiling result + // for the template args directly. } + llvm::FoldingSetNodeID XID, YID; + auto *XConstraint = TXTC->getImmediatelyDeclaredConstraint(); + auto *YConstraint = TYTC->getImmediatelyDeclaredConstraint(); + if (XConstraint) + XConstraint->Profile(XID, *this, /*Canonical=*/true); + if (YConstraint) + YConstraint->Profile(YID, *this, /*Canonical=*/true); + if (XID != YID) + return false; } return true; } Index: clang/test/Modules/concept.cppm =================================================================== --- clang/test/Modules/concept.cppm +++ clang/test/Modules/concept.cppm @@ -18,6 +18,9 @@ template concept __member_size = requires(_Tp &&t) { t.size(); }; +template +concept C = requires(First x, Second y) { x+y; }; + struct A { public: template @@ -29,6 +32,11 @@ constexpr __integer_like auto operator()(_Tp&& __t) const { return __t.size(); } + + template <__integer_like _Tp, C<_Tp> Sentinel> + constexpr _Tp operator()(_Tp &&__t, Sentinel &&last) const { + return __t; + } }; #endif @@ -51,4 +59,5 @@ auto operator+(S s) { return 0; } }; __fn{}(S()); + __fn{}(S(), S()); }