Index: clang/lib/Sema/Sema.cpp =================================================================== --- clang/lib/Sema/Sema.cpp +++ clang/lib/Sema/Sema.cpp @@ -2556,32 +2556,35 @@ bool (*IsPlausibleResult)(QualType)) { SourceLocation Loc = E.get()->getExprLoc(); SourceRange Range = E.get()->getSourceRange(); - - QualType ZeroArgCallTy; UnresolvedSet<4> Overloads; - if (tryExprAsCall(*E.get(), ZeroArgCallTy, Overloads) && - !ZeroArgCallTy.isNull() && - (!IsPlausibleResult || IsPlausibleResult(ZeroArgCallTy))) { - // At this point, we know E is potentially callable with 0 - // arguments and that it returns something of a reasonable type, - // so we can emit a fixit and carry on pretending that E was - // actually a CallExpr. - SourceLocation ParenInsertionLoc = getLocForEndOfToken(Range.getEnd()); - bool IsMV = IsCPUDispatchCPUSpecificMultiVersion(E.get()); - Diag(Loc, PD) << /*zero-arg*/ 1 << IsMV << Range - << (IsCallableWithAppend(E.get()) - ? FixItHint::CreateInsertion(ParenInsertionLoc, "()") - : FixItHint()); - if (!IsMV) - notePlausibleOverloads(*this, Loc, Overloads, IsPlausibleResult); - - // FIXME: Try this before emitting the fixit, and suppress diagnostics - // while doing so. - E = BuildCallExpr(nullptr, E.get(), Range.getEnd(), None, - Range.getEnd().getLocWithOffset(1)); - return true; - } + // If this is a SFINAE context, don't try anything that might trigger ADL + // prematurely. + if (!isSFINAEContext()) { + QualType ZeroArgCallTy; + if (tryExprAsCall(*E.get(), ZeroArgCallTy, Overloads) && + !ZeroArgCallTy.isNull() && + (!IsPlausibleResult || IsPlausibleResult(ZeroArgCallTy))) { + // At this point, we know E is potentially callable with 0 + // arguments and that it returns something of a reasonable type, + // so we can emit a fixit and carry on pretending that E was + // actually a CallExpr. + SourceLocation ParenInsertionLoc = getLocForEndOfToken(Range.getEnd()); + bool IsMV = IsCPUDispatchCPUSpecificMultiVersion(E.get()); + Diag(Loc, PD) << /*zero-arg*/ 1 << IsMV << Range + << (IsCallableWithAppend(E.get()) + ? FixItHint::CreateInsertion(ParenInsertionLoc, "()") + : FixItHint()); + if (!IsMV) + notePlausibleOverloads(*this, Loc, Overloads, IsPlausibleResult); + + // FIXME: Try this before emitting the fixit, and suppress diagnostics + // while doing so. + E = BuildCallExpr(nullptr, E.get(), Range.getEnd(), None, + Range.getEnd().getLocWithOffset(1)); + return true; + } + } if (!ForceComplain) return false; bool IsMV = IsCPUDispatchCPUSpecificMultiVersion(E.get()); Index: clang/lib/Sema/SemaExprMember.cpp =================================================================== --- clang/lib/Sema/SemaExprMember.cpp +++ clang/lib/Sema/SemaExprMember.cpp @@ -1645,6 +1645,9 @@ << BaseType << int(IsArrow) << BaseExpr.get()->getSourceRange() << FixItHint::CreateReplacement(OpLoc, "->"); + if (S.isSFINAEContext()) + return ExprError(); + // Recurse as an -> access. IsArrow = true; return LookupMemberExpr(S, R, BaseExpr, IsArrow, OpLoc, SS, Index: clang/test/SemaCXX/PR52970.cpp =================================================================== --- /dev/null +++ clang/test/SemaCXX/PR52970.cpp @@ -0,0 +1,57 @@ +// RUN: %clang_cc1 -fsyntax-only -std=c++11 -verify %s +// RUN: %clang_cc1 -fsyntax-only -std=c++14 -verify %s +// RUN: %clang_cc1 -fsyntax-only -std=c++17 -verify %s +// RUN: %clang_cc1 -fsyntax-only -std=c++20 -verify %s +// expected-no-diagnostics + +struct Incomplete; +template struct Holder { T t; }; + +namespace DotFollowingFunctionName { +struct Good { + struct Nested { + int b; + } a; +}; + +struct Bad { + Holder a(); +}; + +template +constexpr auto f(T t) -> decltype((t.a.b, true)) { return true; } +constexpr bool f(...) { return false; } + +static_assert(DotFollowingFunctionName::f(Good{}), ""); +static_assert(!DotFollowingFunctionName::f(Bad{}), ""); + +#if __cplusplus >= 202002L +template +concept C = requires(T t) { t.a.b; }; + +static_assert(C); +static_assert(!C); +#endif +} // namespace DotFollowingFunctionName + +namespace DotFollowingPointer { +struct Good { + int begin(); +}; +using Bad = Holder *; + +template +constexpr auto f(T t) -> decltype((t.begin(), true)) { return true; } +constexpr bool f(...) { return false; } + +static_assert(DotFollowingPointer::f(Good{}), ""); +static_assert(!DotFollowingPointer::f(Bad{}), ""); + +#if __cplusplus >= 202002L +template +concept C = requires(T t) { t.begin(); }; + +static_assert(C); +static_assert(!C); +#endif +} // namespace DotFollowingPointer