r294861 - Attributes on K&R C functions should not cause incompatible function type with a redeclaration having the same attribute. Fixing this introduced a secondary problem where we were assuming that K&R functions could not be attributed types when reporting old-style function definitions that are not preceded by a prototype.
Aaron Ballman via cfe-commits
cfe-commits at lists.llvm.org
Sat Feb 11 09:49:54 PST 2017
Author: aaronballman
Date: Sat Feb 11 11:49:53 2017
New Revision: 294861
URL: http://llvm.org/viewvc/llvm-project?rev=294861&view=rev
Log:
Attributes on K&R C functions should not cause incompatible function type with a redeclaration having the same attribute. Fixing this introduced a secondary problem where we were assuming that K&R functions could not be attributed types when reporting old-style function definitions that are not preceded by a prototype.
This patch fixes PR31020.
Modified:
cfe/trunk/include/clang/AST/Type.h
cfe/trunk/include/clang/AST/TypeLoc.h
cfe/trunk/lib/Sema/SemaDecl.cpp
cfe/trunk/test/Sema/knr-def-call.c
cfe/trunk/test/Sema/warn-strict-prototypes.c
Modified: cfe/trunk/include/clang/AST/Type.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/Type.h?rev=294861&r1=294860&r2=294861&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/Type.h (original)
+++ cfe/trunk/include/clang/AST/Type.h Sat Feb 11 11:49:53 2017
@@ -1888,6 +1888,13 @@ public:
/// immediately following this class.
template <typename T> const T *getAs() const;
+ /// Member-template getAsAdjusted<specific type>. Look through specific kinds
+ /// of sugar (parens, attributes, etc) for an instance of \<specific type>.
+ /// This is used when you need to walk over sugar nodes that represent some
+ /// kind of type adjustment from a type that was written as a \<specific type>
+ /// to another type that is still canonically a \<specific type>.
+ template <typename T> const T *getAsAdjusted() const;
+
/// A variant of getAs<> for array types which silently discards
/// qualifiers from the outermost type.
const ArrayType *getAsArrayTypeUnsafe() const;
@@ -6008,6 +6015,38 @@ template <typename T> const T *Type::get
return cast<T>(getUnqualifiedDesugaredType());
}
+template <typename T> const T *Type::getAsAdjusted() const {
+ static_assert(!TypeIsArrayType<T>::value, "ArrayType cannot be used with getAsAdjusted!");
+
+ // If this is directly a T type, return it.
+ if (const T *Ty = dyn_cast<T>(this))
+ return Ty;
+
+ // If the canonical form of this type isn't the right kind, reject it.
+ if (!isa<T>(CanonicalType))
+ return nullptr;
+
+ // Strip off type adjustments that do not modify the underlying nature of the
+ // type.
+ const Type *Ty = this;
+ while (Ty) {
+ if (const auto *A = dyn_cast<AttributedType>(Ty))
+ Ty = A->getModifiedType().getTypePtr();
+ else if (const auto *E = dyn_cast<ElaboratedType>(Ty))
+ Ty = E->desugar().getTypePtr();
+ else if (const auto *P = dyn_cast<ParenType>(Ty))
+ Ty = P->desugar().getTypePtr();
+ else if (const auto *A = dyn_cast<AdjustedType>(Ty))
+ Ty = A->desugar().getTypePtr();
+ else
+ break;
+ }
+
+ // Just because the canonical type is correct does not mean we can use cast<>,
+ // since we may not have stripped off all the sugar down to the base type.
+ return dyn_cast<T>(Ty);
+}
+
inline const ArrayType *Type::getAsArrayTypeUnsafe() const {
// If this is directly an array type, return it.
if (const ArrayType *arr = dyn_cast<ArrayType>(this))
Modified: cfe/trunk/include/clang/AST/TypeLoc.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/TypeLoc.h?rev=294861&r1=294860&r2=294861&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/TypeLoc.h (original)
+++ cfe/trunk/include/clang/AST/TypeLoc.h Sat Feb 11 11:49:53 2017
@@ -70,6 +70,28 @@ public:
return t;
}
+ /// \brief Convert to the specified TypeLoc type, returning a null TypeLoc if
+ /// this TypeLock is not of the desired type. It will consider type
+ /// adjustments from a type that wad written as a T to another type that is
+ /// still canonically a T (ignores parens, attributes, elaborated types, etc).
+ template <typename T>
+ T getAsAdjusted() const {
+ TypeLoc Cur = *this;
+ while (!T::isKind(Cur)) {
+ if (auto PTL = Cur.getAs<ParenTypeLoc>())
+ Cur = PTL.getInnerLoc();
+ else if (auto ATL = Cur.getAs<AttributedTypeLoc>())
+ Cur = ATL.getModifiedLoc();
+ else if (auto ETL = Cur.getAs<ElaboratedTypeLoc>())
+ Cur = ETL.getNamedTypeLoc();
+ else if (auto ATL = Cur.getAs<AdjustedTypeLoc>())
+ Cur = ATL.getOriginalLoc();
+ else
+ break;
+ }
+ return Cur.getAs<T>();
+ }
+
/// The kinds of TypeLocs. Equivalent to the Type::TypeClass enum,
/// except it also defines a Qualified enum that corresponds to the
/// QualifiedLoc class.
Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=294861&r1=294860&r2=294861&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Sat Feb 11 11:49:53 2017
@@ -7564,11 +7564,12 @@ static FunctionDecl* CreateNewFunctionDe
// Determine whether the function was written with a
// prototype. This true when:
// - there is a prototype in the declarator, or
- // - the type R of the function is some kind of typedef or other reference
- // to a type name (which eventually refers to a function type).
+ // - the type R of the function is some kind of typedef or other non-
+ // attributed reference to a type name (which eventually refers to a
+ // function type).
bool HasPrototype =
(D.isFunctionDeclarator() && D.getFunctionTypeInfo().hasPrototype) ||
- (!isa<FunctionType>(R.getTypePtr()) && R->isFunctionProtoType());
+ (!R->getAsAdjusted<FunctionType>() && R->isFunctionProtoType());
NewFD = FunctionDecl::Create(SemaRef.Context, DC,
D.getLocStart(), NameInfo, R,
@@ -12104,7 +12105,7 @@ Decl *Sema::ActOnFinishFunctionBody(Decl
!LangOpts.CPlusPlus) {
TypeSourceInfo *TI = FD->getTypeSourceInfo();
TypeLoc TL = TI->getTypeLoc();
- FunctionTypeLoc FTL = TL.castAs<FunctionTypeLoc>();
+ FunctionTypeLoc FTL = TL.getAsAdjusted<FunctionTypeLoc>();
Diag(FTL.getLParenLoc(), diag::warn_strict_prototypes) << 1;
}
}
Modified: cfe/trunk/test/Sema/knr-def-call.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/knr-def-call.c?rev=294861&r1=294860&r2=294861&view=diff
==============================================================================
--- cfe/trunk/test/Sema/knr-def-call.c (original)
+++ cfe/trunk/test/Sema/knr-def-call.c Sat Feb 11 11:49:53 2017
@@ -39,3 +39,9 @@ void use_proto() {
proto(42.1); // expected-warning{{implicit conversion from 'double' to 'int' changes value from 42.1 to 42}}
(&proto)(42.1); // expected-warning{{implicit conversion from 'double' to 'int' changes value from 42.1 to 42}}
}
+
+// PR31020
+void func(short d) __attribute__((cdecl)); // expected-note{{previous declaration is here}}
+void __attribute__((cdecl)) func(d)
+ short d; // expected-warning{{promoted type 'int' of K&R function parameter is not compatible with the parameter type 'short' declared in a previous prototype}}
+{}
Modified: cfe/trunk/test/Sema/warn-strict-prototypes.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/warn-strict-prototypes.c?rev=294861&r1=294860&r2=294861&view=diff
==============================================================================
--- cfe/trunk/test/Sema/warn-strict-prototypes.c (original)
+++ cfe/trunk/test/Sema/warn-strict-prototypes.c Sat Feb 11 11:49:53 2017
@@ -60,3 +60,8 @@ void foo10(p, p2) void *p; {} // expecte
// K&R function definition with previous prototype declared is not diagnosed.
void foo11(int p, int p2);
void foo11(p, p2) int p; int p2; {}
+
+// PR31020
+void __attribute__((cdecl)) foo12(d) // expected-warning {{this old-style function definition is not preceded by a prototype}}
+ short d;
+{}
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