From: Chandler Carruth Date: Sat, 18 Jun 2011 01:19:03 +0000 (+0000) Subject: Accept no-return stripping conversions for pointer type arguments after X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=18e0461ad72dcf6ec93cd3b1df7bf1b5a30b10b7;p=clang Accept no-return stripping conversions for pointer type arguments after deducing template parameter types. Recently Clang began enforcing the more strict checking that the argument type and the deduced function parameter type (after substitution) match, but that only consideres qualification conversions. One problem with this patch is that we check noreturn conversions and qualification conversions independently. If a valid conversion would require *both*, perhaps interleaved with each other, it will be rejected. If this actually occurs (I'm not yet sure it does) and is in fact a problem (I'm not yet sure it is), there is a FIXME to implement more intelligent conversion checking. However, this step at least allows Clang to resume accepting valid code we're seeing in the wild. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@133327 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h index 577c88c927..06d7d58988 100644 --- a/include/clang/Sema/Sema.h +++ b/include/clang/Sema/Sema.h @@ -1351,6 +1351,8 @@ public: bool IgnoreBaseAccess); bool IsQualificationConversion(QualType FromType, QualType ToType, bool CStyle, bool &ObjCLifetimeConversion); + bool IsNoReturnConversion(QualType FromType, QualType ToType, + QualType &ResultTy); bool DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType); diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp index 2995e2e6e0..eb1d661183 100644 --- a/lib/Sema/SemaOverload.cpp +++ b/lib/Sema/SemaOverload.cpp @@ -924,8 +924,8 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType, /// \brief Determine whether the conversion from FromType to ToType is a valid /// conversion that strips "noreturn" off the nested function type. -static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, - QualType ToType, QualType &ResultTy) { +bool Sema::IsNoReturnConversion(QualType FromType, QualType ToType, + QualType &ResultTy) { if (Context.hasSameUnqualifiedType(FromType, ToType)) return false; @@ -1066,7 +1066,7 @@ static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, S.ExtractUnqualifiedFunctionType(ToType), FromType)) { QualType resultTy; // if the function type matches except for [[noreturn]], it's ok - if (!IsNoReturnConversion(S.Context, FromType, + if (!S.IsNoReturnConversion(FromType, S.ExtractUnqualifiedFunctionType(ToType), resultTy)) // otherwise, only a boolean conversion is standard if (!ToType->isBooleanType()) @@ -1234,7 +1234,7 @@ static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, // Compatible conversions (Clang extension for C function overloading) SCS.Second = ICK_Compatible_Conversion; FromType = ToType.getUnqualifiedType(); - } else if (IsNoReturnConversion(S.Context, FromType, ToType, FromType)) { + } else if (S.IsNoReturnConversion(FromType, ToType, FromType)) { // Treat a conversion that strips "noreturn" as an identity conversion. SCS.Second = ICK_NoReturn_Adjustment; } else if (IsTransparentUnionStandardConversion(S, From, ToType, @@ -7597,8 +7597,8 @@ private: QualType ResultTy; if (Context.hasSameUnqualifiedType(TargetFunctionType, FunDecl->getType()) || - IsNoReturnConversion(Context, FunDecl->getType(), TargetFunctionType, - ResultTy)) { + S.IsNoReturnConversion(FunDecl->getType(), TargetFunctionType, + ResultTy)) { Matches.push_back(std::make_pair(CurAccessFunPair, cast(FunDecl->getCanonicalDecl()))); FoundNonTemplateFunction = true; diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp index b5e9c25d85..dcb4ff2860 100644 --- a/lib/Sema/SemaTemplateDeduction.cpp +++ b/lib/Sema/SemaTemplateDeduction.cpp @@ -2371,9 +2371,16 @@ CheckOriginalCallArgDeduction(Sema &S, Sema::OriginalCallArg OriginalArg, // - The transformed A can be another pointer or pointer to member // type that can be converted to the deduced A via a qualification // conversion. + // + // Also allow conversions which merely strip [[noreturn]] from function types + // (recursively) as an extension. + // FIXME: Currently, this doesn't place nicely with qualfication conversions. bool ObjCLifetimeConversion = false; + QualType ResultTy; if ((A->isAnyPointerType() || A->isMemberPointerType()) && - S.IsQualificationConversion(A, DeducedA, false, ObjCLifetimeConversion)) + (S.IsQualificationConversion(A, DeducedA, false, + ObjCLifetimeConversion) || + S.IsNoReturnConversion(A, DeducedA, ResultTy))) return false; diff --git a/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p3.cpp b/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p3.cpp index f5481c307d..295f080a75 100644 --- a/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p3.cpp +++ b/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p3.cpp @@ -71,7 +71,21 @@ void test_f3(int ***ip, volatile int ***vip) { A a0 = f3(ip); A a1 = f3(vip); } - + +// Also accept conversions for pointer types which require removing +// [[noreturn]]. +namespace noreturn_stripping { + template + void f(R (*function)()); + + void g() __attribute__ ((__noreturn__)); + void h(); + void test() { + f(g); + f(h); + } +} + // - If P is a class, and P has the form template-id, then A can be a // derived class of the deduced A. Likewise, if P is a pointer to a class // of the form template-id, A can be a pointer to a derived class pointed