//===--- SemaInit.cpp - Semantic Analysis for Initializers ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements semantic analysis for initializers. The main entry
// point is Sema::CheckInitList(), but all of the work is performed
// within the InitListChecker class.
//
// This file also implements Sema::CheckInitializerTypes.
//
//===----------------------------------------------------------------------===//
#include "SemaInit.h"
#include "Sema.h"
#include "clang/Parse/Designator.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "llvm/Support/ErrorHandling.h"
#include <map>
using namespace clang;
//===----------------------------------------------------------------------===//
// Sema Initialization Checking
//===----------------------------------------------------------------------===//
static Expr *IsStringInit(Expr *Init, QualType DeclType, ASTContext &Context) {
const ArrayType *AT = Context.getAsArrayType(DeclType);
if (!AT) return 0;
if (!isa<ConstantArrayType>(AT) && !isa<IncompleteArrayType>(AT))
return 0;
// See if this is a string literal or @encode.
Init = Init->IgnoreParens();
// Handle @encode, which is a narrow string.
if (isa<ObjCEncodeExpr>(Init) && AT->getElementType()->isCharType())
return Init;
// Otherwise we can only handle string literals.
StringLiteral *SL = dyn_cast<StringLiteral>(Init);
if (SL == 0) return 0;
QualType ElemTy = Context.getCanonicalType(AT->getElementType());
// char array can be initialized with a narrow string.
// Only allow char x[] = "foo"; not char x[] = L"foo";
if (!SL->isWide())
return ElemTy->isCharType() ? Init : 0;
// wchar_t array can be initialized with a wide string: C99 6.7.8p15 (with
// correction from DR343): "An array with element type compatible with a
// qualified or unqualified version of wchar_t may be initialized by a wide
// string literal, optionally enclosed in braces."
if (Context.typesAreCompatible(Context.getWCharType(),
ElemTy.getUnqualifiedType()))
return Init;
return 0;
}
static bool CheckSingleInitializer(Expr *&Init, QualType DeclType,
bool DirectInit, Sema &S) {
// Get the type before calling CheckSingleAssignmentConstraints(), since
// it can promote the expression.
QualType InitType = Init->getType();
if (S.getLangOptions().CPlusPlus) {
// FIXME: I dislike this error message. A lot.
if (S.PerformImplicitConversion(Init, DeclType,
"initializing", DirectInit)) {
ImplicitConversionSequence ICS;
OverloadCandidateSet CandidateSet;
if (S.IsUserDefinedConversion(Init, DeclType, ICS.UserDefined,
CandidateSet,
true, false, false) != OR_Ambiguous)
return S.Diag(Init->getSourceRange().getBegin(),
diag::err_typecheck_convert_incompatible)
<< DeclType << Init->getType() << "initializing"
<< Init->getSourceRange();
S.Diag(Init->getSourceRange().getBegin(),
diag::err_typecheck_convert_ambiguous)
<< DeclType << Init->getType() << Init->getSourceRange();
S.PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false);
return true;
}
return false;
}
Sema::AssignConvertType ConvTy =
S.CheckSingleAssignmentConstraints(DeclType, Init);
return S.DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType,
InitType, Init, "initializing");
}
static void CheckStringInit(Expr *Str, QualType &DeclT, Sema &S) {
// Get the length of the string as parsed.
uint64_t StrLength =
cast<ConstantArrayType>(Str->getType())->getSize().getZExtValue();
const ArrayType *AT = S.Context.getAsArrayType(DeclT);
if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) {
// C99 6.7.8p14. We have an array of character type with unknown size
// being initialized to a string literal.
llvm::APSInt ConstVal(32);
ConstVal = StrLength;
// Return a new array type (C99 6.7.8p22).
DeclT = S.Context.getConstantArrayType(IAT->getElementType(),
ConstVal,
ArrayType::Normal, 0);
return;
}
const ConstantArrayType *CAT = cast<ConstantArrayType>(AT);
// C99 6.7.8p14. We have an array of character type with known size. However,
// the size may be smaller or larger than the string we are initializing.
// FIXME: Avoid truncation for 64-bit length strings.
if (StrLength-1 > CAT->getSize().getZExtValue())
S.Diag(Str->getSourceRange().getBegin(),
diag::warn_initializer_string_for_char_array_too_long)
<< Str->getSourceRange();
// Set the type to the actual size that we are initializing. If we have
// something like:
// char x[1] = "foo";
// then this will set the string literal's type to char[1].
Str->setType(DeclT);
}
bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType,
SourceLocation InitLoc,
DeclarationName InitEntity, bool DirectInit) {
if (DeclType->isDependentType() ||
Init->isTypeDependent() || Init->isValueDependent()) {
// We have either a dependent type or a type- or value-dependent
// initializer, so we don't perform any additional checking at
// this point.
// If the declaration is a non-dependent, incomplete array type
// that has an initializer, then its type will be completed once
// the initializer is instantiated.
if (!DeclType->isDependentType()) {
if (const IncompleteArrayType *ArrayT
= Context.getAsIncompleteArrayType(DeclType)) {
if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
if (!ILE->isTypeDependent()) {
// Compute the constant array type from the length of the
// initializer list.
// FIXME: This will be wrong if there are designated
// initializations. Good thing they don't exist in C++!
llvm::APInt NumElements(Context.getTypeSize(Context.getSizeType()),
ILE->getNumInits());
llvm::APInt Zero(Context.getTypeSize(Context.getSizeType()), 0);
if (NumElements == Zero) {
// Sizing an array implicitly to zero is not allowed by ISO C,
// but is supported by GNU.
Diag(ILE->getLocStart(), diag::ext_typecheck_zero_array_size);
}
DeclType = Context.getConstantArrayType(ArrayT->getElementType(),
NumElements,
ArrayT->getSizeModifier(),
ArrayT->getIndexTypeCVRQualifiers());
return false;
}
}
// Make the array type-dependent by making it dependently-sized.
DeclType = Context.getDependentSizedArrayType(ArrayT->getElementType(),
/*NumElts=*/0,
ArrayT->getSizeModifier(),
ArrayT->getIndexTypeCVRQualifiers(),
SourceRange());
}
}
return false;
}
// C++ [dcl.init.ref]p1:
// A variable declared to be a T& or T&&, that is "reference to type T"
// (8.3.2), shall be initialized by an object, or function, of
// type T or by an object that can be converted into a T.
if (DeclType->isReferenceType())
return CheckReferenceInit(Init, DeclType, InitLoc,
/*SuppressUserConversions=*/false,
/*AllowExplicit=*/DirectInit,
/*ForceRValue=*/false);
// C99 6.7.8p3: The type of the entity to be initialized shall be an array
// of unknown size ("[]") or an object type that is not a variable array type.
if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType))
return Diag(InitLoc, diag::err_variable_object_no_init)
<< VAT->getSizeExpr()->getSourceRange();
InitListExpr *InitList = dyn_cast<InitListExpr>(Init);
if (!InitList) {
// FIXME: Handle wide strings
if (Expr *Str = IsStringInit(Init, DeclType, Context)) {
CheckStringInit(Str, DeclType, *this);
return false;
}
// C++ [dcl.init]p14:
// -- If the destination type is a (possibly cv-qualified) class
// type:
if (getLangOptions().CPlusPlus && DeclType->isRecordType()) {
QualType DeclTypeC = Context.getCanonicalType(DeclType);
QualType InitTypeC = Context.getCanonicalType(Init->getType());
// -- If the initialization is direct-initialization, or if it is
// copy-initialization where the cv-unqualified version of the
// source type is the same class as, or a derived class of, the
// class of the destination, constructors are considered.
if ((DeclTypeC.getLocalUnqualifiedType()
== InitTypeC.getLocalUnqualifiedType()) ||
IsDerivedFrom(InitTypeC, DeclTypeC)) {
const CXXRecordDecl *RD =
cast<CXXRecordDecl>(DeclType->getAs<RecordType>()->getDecl());
// No need to make a CXXConstructExpr if both the ctor and dtor are
// trivial.
if (RD->hasTrivialConstructor() && RD->hasTrivialDestructor())
return false;
ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(*this);
// FIXME: Poor location information
InitializationKind InitKind
= InitializationKind::CreateCopy(Init->getLocStart(),
SourceLocation());
if (DirectInit)
InitKind = InitializationKind::CreateDirect(Init->getLocStart(),
SourceLocation(),
SourceLocation());
CXXConstructorDecl *Constructor
= PerformInitializationByConstructor(DeclType,
MultiExprArg(*this,
(void **)&Init, 1),
InitLoc, Init->getSourceRange(),
InitEntity, InitKind,
ConstructorArgs);
if (!Constructor)
return true;
OwningExprResult InitResult =
BuildCXXConstructExpr(/*FIXME:ConstructLoc*/SourceLocation(),
DeclType, Constructor,
move_arg(ConstructorArgs));
if (InitResult.isInvalid())
return true;
Init = InitResult.takeAs<Expr>();
return false;
}
// -- Otherwise (i.e., for the remaining copy-initialization
// cases), user-defined conversion sequences that can
// convert from the source type to the destination type or
// (when a conversion function is used) to a derived class
// thereof are enumerated as described in 13.3.1.4, and the
// best one is chosen through overload resolution
// (13.3). If the conversion cannot be done or is
// ambiguous, the initialization is ill-formed. The
// function selected is called with the initializer
// expression as its argument; if the function is a
// constructor, the call initializes a temporary of the
// destination type.
// FIXME: We're pretending to do copy elision here; return to this when we
// have ASTs for such things.
if (!PerformImplicitConversion(Init, DeclType, "initializing"))
return false;
if (InitEntity)
return Diag(InitLoc, diag::err_cannot_initialize_decl)
<< InitEntity << (int)(Init->isLvalue(Context) == Expr::LV_Valid)
<< Init->getType() << Init->getSourceRange();
return Diag(InitLoc, diag::err_cannot_initialize_decl_noname)
<< DeclType << (int)(Init->isLvalue(Context) == Expr::LV_Valid)
<< Init->getType() << Init->getSourceRange();
}
// C99 6.7.8p16.
if (DeclType->isArrayType())
return Diag(Init->getLocStart(), diag::err_array_init_list_required)
<< Init->getSourceRange();
return CheckSingleInitializer(Init, DeclType, DirectInit, *this);
}
bool hadError = CheckInitList(InitList, DeclType);
Init = InitList;
return hadError;
}
//===----------------------------------------------------------------------===//
// Semantic checking for initializer lists.
//===----------------------------------------------------------------------===//
/// @brief Semantic checking for initializer lists.
///
/// The InitListChecker class contains a set of routines that each
/// handle the initialization of a certain kind of entity, e.g.,
/// arrays, vectors, struct/union types, scalars, etc. The
/// InitListChecker itself performs a recursive walk of the subobject
/// structure of the type to be initialized, while stepping through
/// the initializer list one element at a time. The IList and Index
/// parameters to each of the Check* routines contain the active
/// (syntactic) initializer list and the index into that initializer
/// list that represents the current initializer. Each routine is
/// responsible for moving that Index forward as it consumes elements.
///
/// Each Check* routine also has a StructuredList/StructuredIndex
/// arguments, which contains the current the "structured" (semantic)
/// initializer list and the index into that initializer list where we
/// are copying initializers as we map them over to the semantic
/// list. Once we have completed our recursive walk of the subobject
/// structure, we will have constructed a full semantic initializer
/// list.
///
/// C99 designators cause changes in the initializer list traversal,
/// because they make the initialization "jump" into a specific
/// subobject and then continue the initialization from that
/// point. CheckDesignatedInitializer() recursively steps into the
/// designated subobject and manages backing out the recursion to
/// initialize the subobjects after the one designated.
namespace {
class InitListChecker {
Sema &SemaRef;
bool hadError;
std::map<InitListExpr *, InitListExpr *> SyntacticToSemantic;
InitListExpr *FullyStructuredList;
void CheckImplicitInitList(InitListExpr *ParentIList, QualType T,
unsigned &Index, InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool TopLevelObject = false);
void CheckExplicitInitList(InitListExpr *IList, QualType &T,
unsigned &Index, InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool TopLevelObject = false);
void CheckListElementTypes(InitListExpr *IList, QualType &DeclType,
bool SubobjectIsDesignatorContext,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool TopLevelObject = false);
void CheckSubElementType(InitListExpr *IList, QualType ElemType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex);
void CheckScalarType(InitListExpr *IList, QualType DeclType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex);
void CheckReferenceType(InitListExpr *IList, QualType DeclType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex);
void CheckVectorType(InitListExpr *IList, QualType DeclType, unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex);
void CheckStructUnionTypes(InitListExpr *IList, QualType DeclType,
RecordDecl::field_iterator Field,
bool SubobjectIsDesignatorContext, unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool TopLevelObject = false);
void CheckArrayType(InitListExpr *IList, QualType &DeclType,
llvm::APSInt elementIndex,
bool SubobjectIsDesignatorContext, unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex);
bool CheckDesignatedInitializer(InitListExpr *IList, DesignatedInitExpr *DIE,
unsigned DesigIdx,
QualType &CurrentObjectType,
RecordDecl::field_iterator *NextField,
llvm::APSInt *NextElementIndex,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool FinishSubobjectInit,
bool TopLevelObject);
InitListExpr *getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
QualType CurrentObjectType,
InitListExpr *StructuredList,
unsigned StructuredIndex,
SourceRange InitRange);
void UpdateStructuredListElement(InitListExpr *StructuredList,
unsigned &StructuredIndex,
Expr *expr);
int numArrayElements(QualType DeclType);
int numStructUnionElements(QualType DeclType);
void FillInValueInitializations(InitListExpr *ILE);
public:
InitListChecker(Sema &S, InitListExpr *IL, QualType &T);
bool HadError() { return hadError; }
// @brief Retrieves the fully-structured initializer list used for
// semantic analysis and code generation.
InitListExpr *getFullyStructuredList() const { return FullyStructuredList; }
};
} // end anonymous namespace
/// Recursively replaces NULL values within the given initializer list
/// with expressions that perform value-initialization of the
/// appropriate type.
void InitListChecker::FillInValueInitializations(InitListExpr *ILE) {
assert((ILE->getType() != SemaRef.Context.VoidTy) &&
"Should not have void type");
SourceLocation Loc = ILE->getSourceRange().getBegin();
if (ILE->getSyntacticForm())
Loc = ILE->getSyntacticForm()->getSourceRange().getBegin();
if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) {
unsigned Init = 0, NumInits = ILE->getNumInits();
for (RecordDecl::field_iterator
Field = RType->getDecl()->field_begin(),
FieldEnd = RType->getDecl()->field_end();
Field != FieldEnd; ++Field) {
if (Field->isUnnamedBitfield())
continue;
if (Init >= NumInits || !ILE->getInit(Init)) {
if (Field->getType()->isReferenceType()) {
// C++ [dcl.init.aggr]p9:
// If an incomplete or empty initializer-list leaves a
// member of reference type uninitialized, the program is
// ill-formed.
SemaRef.Diag(Loc, diag::err_init_reference_member_uninitialized)
<< Field->getType()
<< ILE->getSyntacticForm()->getSourceRange();
SemaRef.Diag(Field->getLocation(),
diag::note_uninit_reference_member);
hadError = true;
return;
} else if (SemaRef.CheckValueInitialization(Field->getType(), Loc)) {
hadError = true;
return;
}
// FIXME: If value-initialization involves calling a constructor, should
// we make that call explicit in the representation (even when it means
// extending the initializer list)?
if (Init < NumInits && !hadError)
ILE->setInit(Init,
new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()));
} else if (InitListExpr *InnerILE
= dyn_cast<InitListExpr>(ILE->getInit(Init)))
FillInValueInitializations(InnerILE);
++Init;
// Only look at the first initialization of a union.
if (RType->getDecl()->isUnion())
break;
}
return;
}
QualType ElementType;
unsigned NumInits = ILE->getNumInits();
unsigned NumElements = NumInits;
if (const ArrayType *AType = SemaRef.Context.getAsArrayType(ILE->getType())) {
ElementType = AType->getElementType();
if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType))
NumElements = CAType->getSize().getZExtValue();
} else if (const VectorType *VType = ILE->getType()->getAs<VectorType>()) {
ElementType = VType->getElementType();
NumElements = VType->getNumElements();
} else
ElementType = ILE->getType();
for (unsigned Init = 0; Init != NumElements; ++Init) {
if (Init >= NumInits || !ILE->getInit(Init)) {
if (SemaRef.CheckValueInitialization(ElementType, Loc)) {
hadError = true;
return;
}
// FIXME: If value-initialization involves calling a constructor, should
// we make that call explicit in the representation (even when it means
// extending the initializer list)?
if (Init < NumInits && !hadError)
ILE->setInit(Init,
new (SemaRef.Context) ImplicitValueInitExpr(ElementType));
} else if (InitListExpr *InnerILE
= dyn_cast<InitListExpr>(ILE->getInit(Init)))
FillInValueInitializations(InnerILE);
}
}
InitListChecker::InitListChecker(Sema &S, InitListExpr *IL, QualType &T)
: SemaRef(S) {
hadError = false;
unsigned newIndex = 0;
unsigned newStructuredIndex = 0;
FullyStructuredList
= getStructuredSubobjectInit(IL, newIndex, T, 0, 0, IL->getSourceRange());
CheckExplicitInitList(IL, T, newIndex, FullyStructuredList, newStructuredIndex,
/*TopLevelObject=*/true);
if (!hadError)
FillInValueInitializations(FullyStructuredList);
}
int InitListChecker::numArrayElements(QualType DeclType) {
// FIXME: use a proper constant
int maxElements = 0x7FFFFFFF;
if (const ConstantArrayType *CAT =
SemaRef.Context.getAsConstantArrayType(DeclType)) {
maxElements = static_cast<int>(CAT->getSize().getZExtValue());
}
return maxElements;
}
int InitListChecker::numStructUnionElements(QualType DeclType) {
RecordDecl *structDecl = DeclType->getAs<RecordType>()->getDecl();
int InitializableMembers = 0;
for (RecordDecl::field_iterator
Field = structDecl->field_begin(),
FieldEnd = structDecl->field_end();
Field != FieldEnd; ++Field) {
if ((*Field)->getIdentifier() || !(*Field)->isBitField())
++InitializableMembers;
}
if (structDecl->isUnion())
return std::min(InitializableMembers, 1);
return InitializableMembers - structDecl->hasFlexibleArrayMember();
}
void InitListChecker::CheckImplicitInitList(InitListExpr *ParentIList,
QualType T, unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool TopLevelObject) {
int maxElements = 0;
if (T->isArrayType())
maxElements = numArrayElements(T);
else if (T->isStructureType() || T->isUnionType())
maxElements = numStructUnionElements(T);
else if (T->isVectorType())
maxElements = T->getAs<VectorType>()->getNumElements();
else
assert(0 && "CheckImplicitInitList(): Illegal type");
if (maxElements == 0) {
SemaRef.Diag(ParentIList->getInit(Index)->getLocStart(),
diag::err_implicit_empty_initializer);
++Index;
hadError = true;
return;
}
// Build a structured initializer list corresponding to this subobject.
InitListExpr *StructuredSubobjectInitList
= getStructuredSubobjectInit(ParentIList, Index, T, StructuredList,
StructuredIndex,
SourceRange(ParentIList->getInit(Index)->getSourceRange().getBegin(),
ParentIList->getSourceRange().getEnd()));
unsigned StructuredSubobjectInitIndex = 0;
// Check the element types and build the structural subobject.
unsigned StartIndex = Index;
CheckListElementTypes(ParentIList, T, false, Index,
StructuredSubobjectInitList,
StructuredSubobjectInitIndex,
TopLevelObject);
unsigned EndIndex = (Index == StartIndex? StartIndex : Index - 1);
StructuredSubobjectInitList->setType(T);
// Update the structured sub-object initializer so that it's ending
// range corresponds with the end of the last initializer it used.
if (EndIndex < ParentIList->getNumInits()) {
SourceLocation EndLoc
= ParentIList->getInit(EndIndex)->getSourceRange().getEnd();
StructuredSubobjectInitList->setRBraceLoc(EndLoc);
}
}
void InitListChecker::CheckExplicitInitList(InitListExpr *IList, QualType &T,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool TopLevelObject) {
assert(IList->isExplicit() && "Illegal Implicit InitListExpr");
SyntacticToSemantic[IList] = StructuredList;
StructuredList->setSyntacticForm(IList);
CheckListElementTypes(IList, T, true, Index, StructuredList,
StructuredIndex, TopLevelObject);
IList->setType(T);
StructuredList->setType(T);
if (hadError)
return;
if (Index < IList->getNumInits()) {
// We have leftover initializers
if (StructuredIndex == 1 &&
IsStringInit(StructuredList->getInit(0), T, SemaRef.Context)) {
unsigned DK = diag::warn_excess_initializers_in_char_array_initializer;
if (SemaRef.getLangOptions().CPlusPlus) {
DK = diag::err_excess_initializers_in_char_array_initializer;
hadError = true;
}
// Special-case
SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK)
<< IList->getInit(Index)->getSourceRange();
} else if (!T->isIncompleteType()) {
// Don't complain for incomplete types, since we'll get an error
// elsewhere
QualType CurrentObjectType = StructuredList->getType();
int initKind =
CurrentObjectType->isArrayType()? 0 :
CurrentObjectType->isVectorType()? 1 :
CurrentObjectType->isScalarType()? 2 :
CurrentObjectType->isUnionType()? 3 :
4;
unsigned DK = diag::warn_excess_initializers;
if (SemaRef.getLangOptions().CPlusPlus) {
DK = diag::err_excess_initializers;
hadError = true;
}
if (SemaRef.getLangOptions().OpenCL && initKind == 1) {
DK = diag::err_excess_initializers;
hadError = true;
}
SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK)
<< initKind << IList->getInit(Index)->getSourceRange();
}
}
if (T->isScalarType() && !TopLevelObject)
SemaRef.Diag(IList->getLocStart(), diag::warn_braces_around_scalar_init)
<< IList->getSourceRange()
<< CodeModificationHint::CreateRemoval(IList->getLocStart())
<< CodeModificationHint::CreateRemoval(IList->getLocEnd());
}
void InitListChecker::CheckListElementTypes(InitListExpr *IList,
QualType &DeclType,
bool SubobjectIsDesignatorContext,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool TopLevelObject) {
if (DeclType->isScalarType()) {
CheckScalarType(IList, DeclType, Index, StructuredList, StructuredIndex);
} else if (DeclType->isVectorType()) {
CheckVectorType(IList, DeclType, Index, StructuredList, StructuredIndex);
} else if (DeclType->isAggregateType()) {
if (DeclType->isRecordType()) {
RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl();
CheckStructUnionTypes(IList, DeclType, RD->field_begin(),
SubobjectIsDesignatorContext, Index,
StructuredList, StructuredIndex,
TopLevelObject);
} else if (DeclType->isArrayType()) {
llvm::APSInt Zero(
SemaRef.Context.getTypeSize(SemaRef.Context.getSizeType()),
false);
CheckArrayType(IList, DeclType, Zero, SubobjectIsDesignatorContext, Index,
StructuredList, StructuredIndex);
} else
assert(0 && "Aggregate that isn't a structure or array?!");
} else if (DeclType->isVoidType() || DeclType->isFunctionType()) {
// This type is invalid, issue a diagnostic.
++Index;
SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type)
<< DeclType;
hadError = true;
} else if (DeclType->isRecordType()) {
// C++ [dcl.init]p14:
// [...] If the class is an aggregate (8.5.1), and the initializer
// is a brace-enclosed list, see 8.5.1.
//
// Note: 8.5.1 is handled below; here, we diagnose the case where
// we have an initializer list and a destination type that is not
// an aggregate.
// FIXME: In C++0x, this is yet another form of initialization.
SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list)
<< DeclType << IList->getSourceRange();
hadError = true;
} else if (DeclType->isReferenceType()) {
CheckReferenceType(IList, DeclType, Index, StructuredList, StructuredIndex);
} else {
// In C, all types are either scalars or aggregates, but
// additional handling is needed here for C++ (and possibly others?).
assert(0 && "Unsupported initializer type");
}
}
void InitListChecker::CheckSubElementType(InitListExpr *IList,
QualType ElemType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex) {
Expr *expr = IList->getInit(Index);
if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) {
unsigned newIndex = 0;
unsigned newStructuredIndex = 0;
InitListExpr *newStructuredList
= getStructuredSubobjectInit(IList, Index, ElemType,
StructuredList, StructuredIndex,
SubInitList->getSourceRange());
CheckExplicitInitList(SubInitList, ElemType, newIndex,
newStructuredList, newStructuredIndex);
++StructuredIndex;
++Index;
} else if (Expr *Str = IsStringInit(expr, ElemType, SemaRef.Context)) {
CheckStringInit(Str, ElemType, SemaRef);
UpdateStructuredListElement(StructuredList, StructuredIndex, Str);
++Index;
} else if (ElemType->isScalarType()) {
CheckScalarType(IList, ElemType, Index, StructuredList, StructuredIndex);
} else if (ElemType->isReferenceType()) {
CheckReferenceType(IList, ElemType, Index, StructuredList, StructuredIndex);
} else {
if (SemaRef.getLangOptions().CPlusPlus) {
// C++ [dcl.init.aggr]p12:
// All implicit type conversions (clause 4) are considered when
// initializing the aggregate member with an ini- tializer from
// an initializer-list. If the initializer can initialize a
// member, the member is initialized. [...]
ImplicitConversionSequence ICS
= SemaRef.TryCopyInitialization(expr, ElemType,
/*SuppressUserConversions=*/false,
/*ForceRValue=*/false,
/*InOverloadResolution=*/false);
if (ICS.ConversionKind != ImplicitConversionSequence::BadConversion) {
if (SemaRef.PerformImplicitConversion(expr, ElemType, ICS,
"initializing"))
hadError = true;
UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
++Index;
return;
}
// Fall through for subaggregate initialization
} else {
// C99 6.7.8p13:
//
// The initializer for a structure or union object that has
// automatic storage duration shall be either an initializer
// list as described below, or a single expression that has
// compatible structure or union type. In the latter case, the
// initial value of the object, including unnamed members, is
// that of the expression.
if ((ElemType->isRecordType() || ElemType->isVectorType()) &&
SemaRef.Context.hasSameUnqualifiedType(expr->getType(), ElemType)) {
UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
++Index;
return;
}
// Fall through for subaggregate initialization
}
// C++ [dcl.init.aggr]p12:
//
// [...] Otherwise, if the member is itself a non-empty
// subaggregate, brace elision is assumed and the initializer is
// considered for the initialization of the first member of
// the subaggregate.
if (ElemType->isAggregateType() || ElemType->isVectorType()) {
CheckImplicitInitList(IList, ElemType, Index, StructuredList,
StructuredIndex);
++StructuredIndex;
} else {
// We cannot initialize this element, so let
// PerformCopyInitialization produce the appropriate diagnostic.
SemaRef.PerformCopyInitialization(expr, ElemType, "initializing");
hadError = true;
++Index;
++StructuredIndex;
}
}
}
void InitListChecker::CheckScalarType(InitListExpr *IList, QualType DeclType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex) {
if (Index < IList->getNumInits()) {
Expr *expr = IList->getInit(Index);
if (isa<InitListExpr>(expr)) {
SemaRef.Diag(IList->getLocStart(),
diag::err_many_braces_around_scalar_init)
<< IList->getSourceRange();
hadError = true;
++Index;
++StructuredIndex;
return;
} else if (isa<DesignatedInitExpr>(expr)) {
SemaRef.Diag(expr->getSourceRange().getBegin(),
diag::err_designator_for_scalar_init)
<< DeclType << expr->getSourceRange();
hadError = true;
++Index;
++StructuredIndex;
return;
}
Expr *savExpr = expr; // Might be promoted by CheckSingleInitializer.
if (CheckSingleInitializer(expr, DeclType, false, SemaRef))
hadError = true; // types weren't compatible.
else if (savExpr != expr) {
// The type was promoted, update initializer list.
IList->setInit(Index, expr);
}
if (hadError)
++StructuredIndex;
else
UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
++Index;
} else {
SemaRef.Diag(IList->getLocStart(), diag::err_empty_scalar_initializer)
<< IList->getSourceRange();
hadError = true;
++Index;
++StructuredIndex;
return;
}
}
void InitListChecker::CheckReferenceType(InitListExpr *IList, QualType DeclType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex) {
if (Index < IList->getNumInits()) {
Expr *expr = IList->getInit(Index);
if (isa<InitListExpr>(expr)) {
SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list)
<< DeclType << IList->getSourceRange();
hadError = true;
++Index;
++StructuredIndex;
return;
}
Expr *savExpr = expr; // Might be promoted by CheckSingleInitializer.
if (SemaRef.CheckReferenceInit(expr, DeclType,
/*FIXME:*/expr->getLocStart(),
/*SuppressUserConversions=*/false,
/*AllowExplicit=*/false,
/*ForceRValue=*/false))
hadError = true;
else if (savExpr != expr) {
// The type was promoted, update initializer list.
IList->setInit(Index, expr);
}
if (hadError)
++StructuredIndex;
else
UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
++Index;
} else {
// FIXME: It would be wonderful if we could point at the actual member. In
// general, it would be useful to pass location information down the stack,
// so that we know the location (or decl) of the "current object" being
// initialized.
SemaRef.Diag(IList->getLocStart(),
diag::err_init_reference_member_uninitialized)
<< DeclType
<< IList->getSourceRange();
hadError = true;
++Index;
++StructuredIndex;
return;
}
}
void InitListChecker::CheckVectorType(InitListExpr *IList, QualType DeclType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex) {
if (Index < IList->getNumInits()) {
const VectorType *VT = DeclType->getAs<VectorType>();
unsigned maxElements = VT->getNumElements();
unsigned numEltsInit = 0;
QualType elementType = VT->getElementType();
if (!SemaRef.getLangOptions().OpenCL) {
for (unsigned i = 0; i < maxElements; ++i, ++numEltsInit) {
// Don't attempt to go past the end of the init list
if (Index >= IList->getNumInits())
break;
CheckSubElementType(IList, elementType, Index,
StructuredList, StructuredIndex);
}
} else {
// OpenCL initializers allows vectors to be constructed from vectors.
for (unsigned i = 0; i < maxElements; ++i) {
// Don't attempt to go past the end of the init list
if (Index >= IList->getNumInits())
break;
QualType IType = IList->getInit(Index)->getType();
if (!IType->isVectorType()) {
CheckSubElementType(IList, elementType, Index,
StructuredList, StructuredIndex);
++numEltsInit;
} else {
const VectorType *IVT = IType->getAs<VectorType>();
unsigned numIElts = IVT->getNumElements();
QualType VecType = SemaRef.Context.getExtVectorType(elementType,
numIElts);
CheckSubElementType(IList, VecType, Index,
StructuredList, StructuredIndex);
numEltsInit += numIElts;
}
}
}
// OpenCL & AltiVec require all elements to be initialized.
if (numEltsInit != maxElements)
if (SemaRef.getLangOptions().OpenCL || SemaRef.getLangOptions().AltiVec)
SemaRef.Diag(IList->getSourceRange().getBegin(),
diag::err_vector_incorrect_num_initializers)
<< (numEltsInit < maxElements) << maxElements << numEltsInit;
}
}
void InitListChecker::CheckArrayType(InitListExpr *IList, QualType &DeclType,
llvm::APSInt elementIndex,
bool SubobjectIsDesignatorContext,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex) {
// Check for the special-case of initializing an array with a string.
if (Index < IList->getNumInits()) {
if (Expr *Str = IsStringInit(IList->getInit(Index), DeclType,
SemaRef.Context)) {
CheckStringInit(Str, DeclType, SemaRef);
// We place the string literal directly into the resulting
// initializer list. This is the only place where the structure
// of the structured initializer list doesn't match exactly,
// because doing so would involve allocating one character
// constant for each string.
UpdateStructuredListElement(StructuredList, StructuredIndex, Str);
StructuredList->resizeInits(SemaRef.Context, StructuredIndex);
++Index;
return;
}
}
if (const VariableArrayType *VAT =
SemaRef.Context.getAsVariableArrayType(DeclType)) {
// Check for VLAs; in standard C it would be possible to check this
// earlier, but I don't know where clang accepts VLAs (gcc accepts
// them in all sorts of strange places).
SemaRef.Diag(VAT->getSizeExpr()->getLocStart(),
diag::err_variable_object_no_init)
<< VAT->getSizeExpr()->getSourceRange();
hadError = true;
++Index;
++StructuredIndex;
return;
}
// We might know the maximum number of elements in advance.
llvm::APSInt maxElements(elementIndex.getBitWidth(),
elementIndex.isUnsigned());
bool maxElementsKnown = false;
if (const ConstantArrayType *CAT =
SemaRef.Context.getAsConstantArrayType(DeclType)) {
maxElements = CAT->getSize();
elementIndex.extOrTrunc(maxElements.getBitWidth());
elementIndex.setIsUnsigned(maxElements.isUnsigned());
maxElementsKnown = true;
}
QualType elementType = SemaRef.Context.getAsArrayType(DeclType)
->getElementType();
while (Index < IList->getNumInits()) {
Expr *Init = IList->getInit(Index);
if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
// If we're not the subobject that matches up with the '{' for
// the designator, we shouldn't be handling the
// designator. Return immediately.
if (!SubobjectIsDesignatorContext)
return;
// Handle this designated initializer. elementIndex will be
// updated to be the next array element we'll initialize.
if (CheckDesignatedInitializer(IList, DIE, 0,
DeclType, 0, &elementIndex, Index,
StructuredList, StructuredIndex, true,
false)) {
hadError = true;
continue;
}
if (elementIndex.getBitWidth() > maxElements.getBitWidth())
maxElements.extend(elementIndex.getBitWidth());
else if (elementIndex.getBitWidth() < maxElements.getBitWidth())
elementIndex.extend(maxElements.getBitWidth());
elementIndex.setIsUnsigned(maxElements.isUnsigned());
// If the array is of incomplete type, keep track of the number of
// elements in the initializer.
if (!maxElementsKnown && elementIndex > maxElements)
maxElements = elementIndex;
continue;
}
// If we know the maximum number of elements, and we've already
// hit it, stop consuming elements in the initializer list.
if (maxElementsKnown && elementIndex == maxElements)
break;
// Check this element.
CheckSubElementType(IList, elementType, Index,
StructuredList, StructuredIndex);
++elementIndex;
// If the array is of incomplete type, keep track of the number of
// elements in the initializer.
if (!maxElementsKnown && elementIndex > maxElements)
maxElements = elementIndex;
}
if (!hadError && DeclType->isIncompleteArrayType()) {
// If this is an incomplete array type, the actual type needs to
// be calculated here.
llvm::APSInt Zero(maxElements.getBitWidth(), maxElements.isUnsigned());
if (maxElements == Zero) {
// Sizing an array implicitly to zero is not allowed by ISO C,
// but is supported by GNU.
SemaRef.Diag(IList->getLocStart(),
diag::ext_typecheck_zero_array_size);
}
DeclType = SemaRef.Context.getConstantArrayType(elementType, maxElements,
ArrayType::Normal, 0);
}
}
void InitListChecker::CheckStructUnionTypes(InitListExpr *IList,
QualType DeclType,
RecordDecl::field_iterator Field,
bool SubobjectIsDesignatorContext,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool TopLevelObject) {
RecordDecl* structDecl = DeclType->getAs<RecordType>()->getDecl();
// If the record is invalid, some of it's members are invalid. To avoid
// confusion, we forgo checking the intializer for the entire record.
if (structDecl->isInvalidDecl()) {
hadError = true;
return;
}
if (DeclType->isUnionType() && IList->getNumInits() == 0) {
// Value-initialize the first named member of the union.
RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl();
for (RecordDecl::field_iterator FieldEnd = RD->field_end();
Field != FieldEnd; ++Field) {
if (Field->getDeclName()) {
StructuredList->setInitializedFieldInUnion(*Field);
break;
}
}
return;
}
// If structDecl is a forward declaration, this loop won't do
// anything except look at designated initializers; That's okay,
// because an error should get printed out elsewhere. It might be
// worthwhile to skip over the rest of the initializer, though.
RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl();
RecordDecl::field_iterator FieldEnd = RD->field_end();
bool InitializedSomething = false;
while (Index < IList->getNumInits()) {
Expr *Init = IList->getInit(Index);
if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
// If we're not the subobject that matches up with the '{' for
// the designator, we shouldn't be handling the
// designator. Return immediately.
if (!SubobjectIsDesignatorContext)
return;
// Handle this designated initializer. Field will be updated to
// the next field that we'll be initializing.
if (CheckDesignatedInitializer(IList, DIE, 0,
DeclType, &Field, 0, Index,
StructuredList, StructuredIndex,
true, TopLevelObject))
hadError = true;
InitializedSomething = true;
continue;
}
if (Field == FieldEnd) {
// We've run out of fields. We're done.
break;
}
// We've already initialized a member of a union. We're done.
if (InitializedSomething && DeclType->isUnionType())
break;
// If we've hit the flexible array member at the end, we're done.
if (Field->getType()->isIncompleteArrayType())
break;
if (Field->isUnnamedBitfield()) {
// Don't initialize unnamed bitfields, e.g. "int : 20;"
++Field;
continue;
}
CheckSubElementType(IList, Field->getType(), Index,
StructuredList, StructuredIndex);
InitializedSomething = true;
if (DeclType->isUnionType()) {
// Initialize the first field within the union.
StructuredList->setInitializedFieldInUnion(*Field);
}
++Field;
}
if (Field == FieldEnd || !Field->getType()->isIncompleteArrayType() ||
Index >= IList->getNumInits())
return;
// Handle GNU flexible array initializers.
if (!TopLevelObject &&
(!isa<InitListExpr>(IList->getInit(Index)) ||
cast<InitListExpr>(IList->getInit(Index))->getNumInits() > 0)) {
SemaRef.Diag(IList->getInit(Index)->getSourceRange().getBegin(),
diag::err_flexible_array_init_nonempty)
<< IList->getInit(Index)->getSourceRange().getBegin();
SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
<< *Field;
hadError = true;
++Index;
return;
} else {
SemaRef.Diag(IList->getInit(Index)->getSourceRange().getBegin(),
diag::ext_flexible_array_init)
<< IList->getInit(Index)->getSourceRange().getBegin();
SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
<< *Field;
}
if (isa<InitListExpr>(IList->getInit(Index)))
CheckSubElementType(IList, Field->getType(), Index, StructuredList,
StructuredIndex);
else
CheckImplicitInitList(IList, Field->getType(), Index, StructuredList,
StructuredIndex);
}
/// \brief Expand a field designator that refers to a member of an
/// anonymous struct or union into a series of field designators that
/// refers to the field within the appropriate subobject.
///
/// Field/FieldIndex will be updated to point to the (new)
/// currently-designated field.
static void ExpandAnonymousFieldDesignator(Sema &SemaRef,
DesignatedInitExpr *DIE,
unsigned DesigIdx,
FieldDecl *Field,
RecordDecl::field_iterator &FieldIter,
unsigned &FieldIndex) {
typedef DesignatedInitExpr::Designator Designator;
// Build the path from the current object to the member of the
// anonymous struct/union (backwards).
llvm::SmallVector<FieldDecl *, 4> Path;
SemaRef.BuildAnonymousStructUnionMemberPath(Field, Path);
// Build the replacement designators.
llvm::SmallVector<Designator, 4> Replacements;
for (llvm::SmallVector<FieldDecl *, 4>::reverse_iterator
FI = Path.rbegin(), FIEnd = Path.rend();
FI != FIEnd; ++FI) {
if (FI + 1 == FIEnd)
Replacements.push_back(Designator((IdentifierInfo *)0,
DIE->getDesignator(DesigIdx)->getDotLoc(),
DIE->getDesignator(DesigIdx)->getFieldLoc()));
else
Replacements.push_back(Designator((IdentifierInfo *)0, SourceLocation(),
SourceLocation()));
Replacements.back().setField(*FI);
}
// Expand the current designator into the set of replacement
// designators, so we have a full subobject path down to where the
// member of the anonymous struct/union is actually stored.
DIE->ExpandDesignator(DesigIdx, &Replacements[0],
&Replacements[0] + Replacements.size());
// Update FieldIter/FieldIndex;
RecordDecl *Record = cast<RecordDecl>(Path.back()->getDeclContext());
FieldIter = Record->field_begin();
FieldIndex = 0;
for (RecordDecl::field_iterator FEnd = Record->field_end();
FieldIter != FEnd; ++FieldIter) {
if (FieldIter->isUnnamedBitfield())
continue;
if (*FieldIter == Path.back())
return;
++FieldIndex;
}
assert(false && "Unable to find anonymous struct/union field");
}
/// @brief Check the well-formedness of a C99 designated initializer.
///
/// Determines whether the designated initializer @p DIE, which
/// resides at the given @p Index within the initializer list @p
/// IList, is well-formed for a current object of type @p DeclType
/// (C99 6.7.8). The actual subobject that this designator refers to
/// within the current subobject is returned in either
/// @p NextField or @p NextElementIndex (whichever is appropriate).
///
/// @param IList The initializer list in which this designated
/// initializer occurs.
///
/// @param DIE The designated initializer expression.
///
/// @param DesigIdx The index of the current designator.
///
/// @param DeclType The type of the "current object" (C99 6.7.8p17),
/// into which the designation in @p DIE should refer.
///
/// @param NextField If non-NULL and the first designator in @p DIE is
/// a field, this will be set to the field declaration corresponding
/// to the field named by the designator.
///
/// @param NextElementIndex If non-NULL and the first designator in @p
/// DIE is an array designator or GNU array-range designator, this
/// will be set to the last index initialized by this designator.
///
/// @param Index Index into @p IList where the designated initializer
/// @p DIE occurs.
///
/// @param StructuredList The initializer list expression that
/// describes all of the subobject initializers in the order they'll
/// actually be initialized.
///
/// @returns true if there was an error, false otherwise.
bool
InitListChecker::CheckDesignatedInitializer(InitListExpr *IList,
DesignatedInitExpr *DIE,
unsigned DesigIdx,
QualType &CurrentObjectType,
RecordDecl::field_iterator *NextField,
llvm::APSInt *NextElementIndex,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool FinishSubobjectInit,
bool TopLevelObject) {
if (DesigIdx == DIE->size()) {
// Check the actual initialization for the designated object type.
bool prevHadError = hadError;
// Temporarily remove the designator expression from the
// initializer list that the child calls see, so that we don't try
// to re-process the designator.
unsigned OldIndex = Index;
IList->setInit(OldIndex, DIE->getInit());
CheckSubElementType(IList, CurrentObjectType, Index,
StructuredList, StructuredIndex);
// Restore the designated initializer expression in the syntactic
// form of the initializer list.
if (IList->getInit(OldIndex) != DIE->getInit())
DIE->setInit(IList->getInit(OldIndex));
IList->setInit(OldIndex, DIE);
return hadError && !prevHadError;
}
bool IsFirstDesignator = (DesigIdx == 0);
assert((IsFirstDesignator || StructuredList) &&
"Need a non-designated initializer list to start from");
DesignatedInitExpr::Designator *D = DIE->getDesignator(DesigIdx);
// Determine the structural initializer list that corresponds to the
// current subobject.
StructuredList = IsFirstDesignator? SyntacticToSemantic[IList]
: getStructuredSubobjectInit(IList, Index, CurrentObjectType,
StructuredList, StructuredIndex,
SourceRange(D->getStartLocation(),
DIE->getSourceRange().getEnd()));
assert(StructuredList && "Expected a structured initializer list");
if (D->isFieldDesignator()) {
// C99 6.7.8p7:
//
// If a designator has the form
//
// . identifier
//
// then the current object (defined below) shall have
// structure or union type and the identifier shall be the
// name of a member of that type.
const RecordType *RT = CurrentObjectType->getAs<RecordType>();
if (!RT) {
SourceLocation Loc = D->getDotLoc();
if (Loc.isInvalid())
Loc = D->getFieldLoc();
SemaRef.Diag(Loc, diag::err_field_designator_non_aggr)
<< SemaRef.getLangOptions().CPlusPlus << CurrentObjectType;
++Index;
return true;
}
// Note: we perform a linear search of the fields here, despite
// the fact that we have a faster lookup method, because we always
// need to compute the field's index.
FieldDecl *KnownField = D->getField();
IdentifierInfo *FieldName = D->getFieldName();
unsigned FieldIndex = 0;
RecordDecl::field_iterator
Field = RT->getDecl()->field_begin(),
FieldEnd = RT->getDecl()->field_end();
for (; Field != FieldEnd; ++Field) {
if (Field->isUnnamedBitfield())
continue;
if (KnownField == *Field || Field->getIdentifier() == FieldName)
break;
++FieldIndex;
}
if (Field == FieldEnd) {
// There was no normal field in the struct with the designated
// name. Perform another lookup for this name, which may find
// something that we can't designate (e.g., a member function),
// may find nothing, or may find a member of an anonymous
// struct/union.
DeclContext::lookup_result Lookup = RT->getDecl()->lookup(FieldName);
if (Lookup.first == Lookup.second) {
// Name lookup didn't find anything.
SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown)
<< FieldName << CurrentObjectType;
++Index;
return true;
} else if (!KnownField && isa<FieldDecl>(*Lookup.first) &&
cast<RecordDecl>((*Lookup.first)->getDeclContext())
->isAnonymousStructOrUnion()) {
// Handle an field designator that refers to a member of an
// anonymous struct or union.
ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx,
cast<FieldDecl>(*Lookup.first),
Field, FieldIndex);
D = DIE->getDesignator(DesigIdx);
} else {
// Name lookup found something, but it wasn't a field.
SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_nonfield)
<< FieldName;
SemaRef.Diag((*Lookup.first)->getLocation(),
diag::note_field_designator_found);
++Index;
return true;
}
} else if (!KnownField &&
cast<RecordDecl>((*Field)->getDeclContext())
->isAnonymousStructOrUnion()) {
ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, *Field,
Field, FieldIndex);
D = DIE->getDesignator(DesigIdx);
}
// All of the fields of a union are located at the same place in
// the initializer list.
if (RT->getDecl()->isUnion()) {
FieldIndex = 0;
StructuredList->setInitializedFieldInUnion(*Field);
}
// Update the designator with the field declaration.
D->setField(*Field);
// Make sure that our non-designated initializer list has space
// for a subobject corresponding to this field.
if (FieldIndex >= StructuredList->getNumInits())
StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1);
// This designator names a flexible array member.
if (Field->getType()->isIncompleteArrayType()) {
bool Invalid = false;
if ((DesigIdx + 1) != DIE->size()) {
// We can't designate an object within the flexible array
// member (because GCC doesn't allow it).
DesignatedInitExpr::Designator *NextD
= DIE->getDesignator(DesigIdx + 1);
SemaRef.Diag(NextD->getStartLocation(),
diag::err_designator_into_flexible_array_member)
<< SourceRange(NextD->getStartLocation(),
DIE->getSourceRange().getEnd());
SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
<< *Field;
Invalid = true;
}
if (!hadError && !isa<InitListExpr>(DIE->getInit())) {
// The initializer is not an initializer list.
SemaRef.Diag(DIE->getInit()->getSourceRange().getBegin(),
diag::err_flexible_array_init_needs_braces)
<< DIE->getInit()->getSourceRange();
SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
<< *Field;
Invalid = true;
}
// Handle GNU flexible array initializers.
if (!Invalid && !TopLevelObject &&
cast<InitListExpr>(DIE->getInit())->getNumInits() > 0) {
SemaRef.Diag(DIE->getSourceRange().getBegin(),
diag::err_flexible_array_init_nonempty)
<< DIE->getSourceRange().getBegin();
SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
<< *Field;
Invalid = true;
}
if (Invalid) {
++Index;
return true;
}
// Initialize the array.
bool prevHadError = hadError;
unsigned newStructuredIndex = FieldIndex;
unsigned OldIndex = Index;
IList->setInit(Index, DIE->getInit());
CheckSubElementType(IList, Field->getType(), Index,
StructuredList, newStructuredIndex);
IList->setInit(OldIndex, DIE);
if (hadError && !prevHadError) {
++Field;
++FieldIndex;
if (NextField)
*NextField = Field;
StructuredIndex = FieldIndex;
return true;
}
} else {
// Recurse to check later designated subobjects.
QualType FieldType = (*Field)->getType();
unsigned newStructuredIndex = FieldIndex;
if (CheckDesignatedInitializer(IList, DIE, DesigIdx + 1, FieldType, 0, 0,
Index, StructuredList, newStructuredIndex,
true, false))
return true;
}
// Find the position of the next field to be initialized in this
// subobject.
++Field;
++FieldIndex;
// If this the first designator, our caller will continue checking
// the rest of this struct/class/union subobject.
if (IsFirstDesignator) {
if (NextField)
*NextField = Field;
StructuredIndex = FieldIndex;
return false;
}
if (!FinishSubobjectInit)
return false;
// We've already initialized something in the union; we're done.
if (RT->getDecl()->isUnion())
return hadError;
// Check the remaining fields within this class/struct/union subobject.
bool prevHadError = hadError;
CheckStructUnionTypes(IList, CurrentObjectType, Field, false, Index,
StructuredList, FieldIndex);
return hadError && !prevHadError;
}
// C99 6.7.8p6:
//
// If a designator has the form
//
// [ constant-expression ]
//
// then the current object (defined below) shall have array
// type and the expression shall be an integer constant
// expression. If the array is of unknown size, any
// nonnegative value is valid.
//
// Additionally, cope with the GNU extension that permits
// designators of the form
//
// [ constant-expression ... constant-expression ]
const ArrayType *AT = SemaRef.Context.getAsArrayType(CurrentObjectType);
if (!AT) {
SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array)
<< CurrentObjectType;
++Index;
return true;
}
Expr *IndexExpr = 0;
llvm::APSInt DesignatedStartIndex, DesignatedEndIndex;
if (D->isArrayDesignator()) {
IndexExpr = DIE->getArrayIndex(*D);
DesignatedStartIndex = IndexExpr->EvaluateAsInt(SemaRef.Context);
DesignatedEndIndex = DesignatedStartIndex;
} else {
assert(D->isArrayRangeDesignator() && "Need array-range designator");
DesignatedStartIndex =
DIE->getArrayRangeStart(*D)->EvaluateAsInt(SemaRef.Context);
DesignatedEndIndex =
DIE->getArrayRangeEnd(*D)->EvaluateAsInt(SemaRef.Context);
IndexExpr = DIE->getArrayRangeEnd(*D);
if (DesignatedStartIndex.getZExtValue() !=DesignatedEndIndex.getZExtValue())
FullyStructuredList->sawArrayRangeDesignator();
}
if (isa<ConstantArrayType>(AT)) {
llvm::APSInt MaxElements(cast<ConstantArrayType>(AT)->getSize(), false);
DesignatedStartIndex.extOrTrunc(MaxElements.getBitWidth());
DesignatedStartIndex.setIsUnsigned(MaxElements.isUnsigned());
DesignatedEndIndex.extOrTrunc(MaxElements.getBitWidth());
DesignatedEndIndex.setIsUnsigned(MaxElements.isUnsigned());
if (DesignatedEndIndex >= MaxElements) {
SemaRef.Diag(IndexExpr->getSourceRange().getBegin(),
diag::err_array_designator_too_large)
<< DesignatedEndIndex.toString(10) << MaxElements.toString(10)
<< IndexExpr->getSourceRange();
++Index;
return true;
}
} else {
// Make sure the bit-widths and signedness match.
if (DesignatedStartIndex.getBitWidth() > DesignatedEndIndex.getBitWidth())
DesignatedEndIndex.extend(DesignatedStartIndex.getBitWidth());
else if (DesignatedStartIndex.getBitWidth() <
DesignatedEndIndex.getBitWidth())
DesignatedStartIndex.extend(DesignatedEndIndex.getBitWidth());
DesignatedStartIndex.setIsUnsigned(true);
DesignatedEndIndex.setIsUnsigned(true);
}
// Make sure that our non-designated initializer list has space
// for a subobject corresponding to this array element.
if (DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits())
StructuredList->resizeInits(SemaRef.Context,
DesignatedEndIndex.getZExtValue() + 1);
// Repeatedly perform subobject initializations in the range
// [DesignatedStartIndex, DesignatedEndIndex].
// Move to the next designator
unsigned ElementIndex = DesignatedStartIndex.getZExtValue();
unsigned OldIndex = Index;
while (DesignatedStartIndex <= DesignatedEndIndex) {
// Recurse to check later designated subobjects.
QualType ElementType = AT->getElementType();
Index = OldIndex;
if (CheckDesignatedInitializer(IList, DIE, DesigIdx + 1, ElementType, 0, 0,
Index, StructuredList, ElementIndex,
(DesignatedStartIndex == DesignatedEndIndex),
false))
return true;
// Move to the next index in the array that we'll be initializing.
++DesignatedStartIndex;
ElementIndex = DesignatedStartIndex.getZExtValue();
}
// If this the first designator, our caller will continue checking
// the rest of this array subobject.
if (IsFirstDesignator) {
if (NextElementIndex)
*NextElementIndex = DesignatedStartIndex;
StructuredIndex = ElementIndex;
return false;
}
if (!FinishSubobjectInit)
return false;
// Check the remaining elements within this array subobject.
bool prevHadError = hadError;
CheckArrayType(IList, CurrentObjectType, DesignatedStartIndex, false, Index,
StructuredList, ElementIndex);
return hadError && !prevHadError;
}
// Get the structured initializer list for a subobject of type
// @p CurrentObjectType.
InitListExpr *
InitListChecker::getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
QualType CurrentObjectType,
InitListExpr *StructuredList,
unsigned StructuredIndex,
SourceRange InitRange) {
Expr *ExistingInit = 0;
if (!StructuredList)
ExistingInit = SyntacticToSemantic[IList];
else if (StructuredIndex < StructuredList->getNumInits())
ExistingInit = StructuredList->getInit(StructuredIndex);
if (InitListExpr *Result = dyn_cast_or_null<InitListExpr>(ExistingInit))
return Result;
if (ExistingInit) {
// We are creating an initializer list that initializes the
// subobjects of the current object, but there was already an
// initialization that completely initialized the current
// subobject, e.g., by a compound literal:
//
// struct X { int a, b; };
// struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 };
//
// Here, xs[0].a == 0 and xs[0].b == 3, since the second,
// designated initializer re-initializes the whole
// subobject [0], overwriting previous initializers.
SemaRef.Diag(InitRange.getBegin(),
diag::warn_subobject_initializer_overrides)
<< InitRange;
SemaRef.Diag(ExistingInit->getSourceRange().getBegin(),
diag::note_previous_initializer)
<< /*FIXME:has side effects=*/0
<< ExistingInit->getSourceRange();
}
InitListExpr *Result
= new (SemaRef.Context) InitListExpr(InitRange.getBegin(), 0, 0,
InitRange.getEnd());
Result->setType(CurrentObjectType);
// Pre-allocate storage for the structured initializer list.
unsigned NumElements = 0;
unsigned NumInits = 0;
if (!StructuredList)
NumInits = IList->getNumInits();
else if (Index < IList->getNumInits()) {
if (InitListExpr *SubList = dyn_cast<InitListExpr>(IList->getInit(Index)))
NumInits = SubList->getNumInits();
}
if (const ArrayType *AType
= SemaRef.Context.getAsArrayType(CurrentObjectType)) {
if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) {
NumElements = CAType->getSize().getZExtValue();
// Simple heuristic so that we don't allocate a very large
// initializer with many empty entries at the end.
if (NumInits && NumElements > NumInits)
NumElements = 0;
}
} else if (const VectorType *VType = CurrentObjectType->getAs<VectorType>())
NumElements = VType->getNumElements();
else if (const RecordType *RType = CurrentObjectType->getAs<RecordType>()) {
RecordDecl *RDecl = RType->getDecl();
if (RDecl->isUnion())
NumElements = 1;
else
NumElements = std::distance(RDecl->field_begin(),
RDecl->field_end());
}
if (NumElements < NumInits)
NumElements = IList->getNumInits();
Result->reserveInits(NumElements);
// Link this new initializer list into the structured initializer
// lists.
if (StructuredList)
StructuredList->updateInit(StructuredIndex, Result);
else {
Result->setSyntacticForm(IList);
SyntacticToSemantic[IList] = Result;
}
return Result;
}
/// Update the initializer at index @p StructuredIndex within the
/// structured initializer list to the value @p expr.
void InitListChecker::UpdateStructuredListElement(InitListExpr *StructuredList,
unsigned &StructuredIndex,
Expr *expr) {
// No structured initializer list to update
if (!StructuredList)
return;
if (Expr *PrevInit = StructuredList->updateInit(StructuredIndex, expr)) {
// This initializer overwrites a previous initializer. Warn.
SemaRef.Diag(expr->getSourceRange().getBegin(),
diag::warn_initializer_overrides)
<< expr->getSourceRange();
SemaRef.Diag(PrevInit->getSourceRange().getBegin(),
diag::note_previous_initializer)
<< /*FIXME:has side effects=*/0
<< PrevInit->getSourceRange();
}
++StructuredIndex;
}
/// Check that the given Index expression is a valid array designator
/// value. This is essentailly just a wrapper around
/// VerifyIntegerConstantExpression that also checks for negative values
/// and produces a reasonable diagnostic if there is a
/// failure. Returns true if there was an error, false otherwise. If
/// everything went okay, Value will receive the value of the constant
/// expression.
static bool
CheckArrayDesignatorExpr(Sema &S, Expr *Index, llvm::APSInt &Value) {
SourceLocation Loc = Index->getSourceRange().getBegin();
// Make sure this is an integer constant expression.
if (S.VerifyIntegerConstantExpression(Index, &Value))
return true;
if (Value.isSigned() && Value.isNegative())
return S.Diag(Loc, diag::err_array_designator_negative)
<< Value.toString(10) << Index->getSourceRange();
Value.setIsUnsigned(true);
return false;
}
Sema::OwningExprResult Sema::ActOnDesignatedInitializer(Designation &Desig,
SourceLocation Loc,
bool GNUSyntax,
OwningExprResult Init) {
typedef DesignatedInitExpr::Designator ASTDesignator;
bool Invalid = false;
llvm::SmallVector<ASTDesignator, 32> Designators;
llvm::SmallVector<Expr *, 32> InitExpressions;
// Build designators and check array designator expressions.
for (unsigned Idx = 0; Idx < Desig.getNumDesignators(); ++Idx) {
const Designator &D = Desig.getDesignator(Idx);
switch (D.getKind()) {
case Designator::FieldDesignator:
Designators.push_back(ASTDesignator(D.getField(), D.getDotLoc(),
D.getFieldLoc()));
break;
case Designator::ArrayDesignator: {
Expr *Index = static_cast<Expr *>(D.getArrayIndex());
llvm::APSInt IndexValue;
if (!Index->isTypeDependent() &&
!Index->isValueDependent() &&
CheckArrayDesignatorExpr(*this, Index, IndexValue))
Invalid = true;
else {
Designators.push_back(ASTDesignator(InitExpressions.size(),
D.getLBracketLoc(),
D.getRBracketLoc()));
InitExpressions.push_back(Index);
}
break;
}
case Designator::ArrayRangeDesignator: {
Expr *StartIndex = static_cast<Expr *>(D.getArrayRangeStart());
Expr *EndIndex = static_cast<Expr *>(D.getArrayRangeEnd());
llvm::APSInt StartValue;
llvm::APSInt EndValue;
bool StartDependent = StartIndex->isTypeDependent() ||
StartIndex->isValueDependent();
bool EndDependent = EndIndex->isTypeDependent() ||
EndIndex->isValueDependent();
if ((!StartDependent &&
CheckArrayDesignatorExpr(*this, StartIndex, StartValue)) ||
(!EndDependent &&
CheckArrayDesignatorExpr(*this, EndIndex, EndValue)))
Invalid = true;
else {
// Make sure we're comparing values with the same bit width.
if (StartDependent || EndDependent) {
// Nothing to compute.
} else if (StartValue.getBitWidth() > EndValue.getBitWidth())
EndValue.extend(StartValue.getBitWidth());
else if (StartValue.getBitWidth() < EndValue.getBitWidth())
StartValue.extend(EndValue.getBitWidth());
if (!StartDependent && !EndDependent && EndValue < StartValue) {
Diag(D.getEllipsisLoc(), diag::err_array_designator_empty_range)
<< StartValue.toString(10) << EndValue.toString(10)
<< StartIndex->getSourceRange() << EndIndex->getSourceRange();
Invalid = true;
} else {
Designators.push_back(ASTDesignator(InitExpressions.size(),
D.getLBracketLoc(),
D.getEllipsisLoc(),
D.getRBracketLoc()));
InitExpressions.push_back(StartIndex);
InitExpressions.push_back(EndIndex);
}
}
break;
}
}
}
if (Invalid || Init.isInvalid())
return ExprError();
// Clear out the expressions within the designation.
Desig.ClearExprs(*this);
DesignatedInitExpr *DIE
= DesignatedInitExpr::Create(Context,
Designators.data(), Designators.size(),
InitExpressions.data(), InitExpressions.size(),
Loc, GNUSyntax, Init.takeAs<Expr>());
return Owned(DIE);
}
bool Sema::CheckInitList(InitListExpr *&InitList, QualType &DeclType) {
InitListChecker CheckInitList(*this, InitList, DeclType);
if (!CheckInitList.HadError())
InitList = CheckInitList.getFullyStructuredList();
return CheckInitList.HadError();
}
/// \brief Diagnose any semantic errors with value-initialization of
/// the given type.
///
/// Value-initialization effectively zero-initializes any types
/// without user-declared constructors, and calls the default
/// constructor for a for any type that has a user-declared
/// constructor (C++ [dcl.init]p5). Value-initialization can fail when
/// a type with a user-declared constructor does not have an
/// accessible, non-deleted default constructor. In C, everything can
/// be value-initialized, which corresponds to C's notion of
/// initializing objects with static storage duration when no
/// initializer is provided for that object.
///
/// \returns true if there was an error, false otherwise.
bool Sema::CheckValueInitialization(QualType Type, SourceLocation Loc) {
// C++ [dcl.init]p5:
//
// To value-initialize an object of type T means:
// -- if T is an array type, then each element is value-initialized;
if (const ArrayType *AT = Context.getAsArrayType(Type))
return CheckValueInitialization(AT->getElementType(), Loc);
if (const RecordType *RT = Type->getAs<RecordType>()) {
if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
// -- if T is a class type (clause 9) with a user-declared
// constructor (12.1), then the default constructor for T is
// called (and the initialization is ill-formed if T has no
// accessible default constructor);
if (ClassDecl->hasUserDeclaredConstructor()) {
ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(*this);
// FIXME: Poor location information
CXXConstructorDecl *Constructor
= PerformInitializationByConstructor(Type,
MultiExprArg(*this, 0, 0),
Loc, SourceRange(Loc),
DeclarationName(),
InitializationKind::CreateValue(Loc, Loc, Loc),
ConstructorArgs);
if (!Constructor)
return true;
OwningExprResult Init
= BuildCXXConstructExpr(Loc, Type, Constructor,
move_arg(ConstructorArgs));
if (Init.isInvalid())
return true;
// FIXME: Actually perform the value-initialization!
return false;
}
}
}
if (Type->isReferenceType()) {
// C++ [dcl.init]p5:
// [...] A program that calls for default-initialization or
// value-initialization of an entity of reference type is
// ill-formed. [...]
// FIXME: Once we have code that goes through this path, add an actual
// diagnostic :)
}
return false;
}
//===----------------------------------------------------------------------===//
// Initialization entity
//===----------------------------------------------------------------------===//
void InitializedEntity::InitDeclLoc() {
assert((Kind == EK_Variable || Kind == EK_Parameter || Kind == EK_Member) &&
"InitDeclLoc cannot be used with non-declaration entities.");
if (TypeSourceInfo *DI = VariableOrMember->getTypeSourceInfo()) {
TL = DI->getTypeLoc();
return;
}
// FIXME: Once we've gone through the effort to create the fake
// TypeSourceInfo, should we cache it in the declaration?
// (If not, we "leak" it).
TypeSourceInfo *DI = VariableOrMember->getASTContext()
.CreateTypeSourceInfo(VariableOrMember->getType());
DI->getTypeLoc().initialize(VariableOrMember->getLocation());
TL = DI->getTypeLoc();
}
InitializedEntity InitializedEntity::InitializeBase(ASTContext &Context,
CXXBaseSpecifier *Base)
{
InitializedEntity Result;
Result.Kind = EK_Base;
Result.Base = Base;
// FIXME: CXXBaseSpecifier should store a TypeLoc.
TypeSourceInfo *DI = Context.CreateTypeSourceInfo(Base->getType());
DI->getTypeLoc().initialize(Base->getSourceRange().getBegin());
Result.TL = DI->getTypeLoc();
return Result;
}
//===----------------------------------------------------------------------===//
// Initialization sequence
//===----------------------------------------------------------------------===//
void InitializationSequence::Step::Destroy() {
switch (Kind) {
case SK_ResolveAddressOfOverloadedFunction:
case SK_CastDerivedToBaseRValue:
case SK_CastDerivedToBaseLValue:
case SK_BindReference:
case SK_BindReferenceToTemporary:
case SK_UserConversion:
case SK_QualificationConversionRValue:
case SK_QualificationConversionLValue:
case SK_ListInitialization:
case SK_ConstructorInitialization:
case SK_ZeroInitialization:
break;
case SK_ConversionSequence:
delete ICS;
}
}
void InitializationSequence::AddAddressOverloadResolutionStep(
FunctionDecl *Function) {
Step S;
S.Kind = SK_ResolveAddressOfOverloadedFunction;
S.Type = Function->getType();
S.Function = Function;
Steps.push_back(S);
}
void InitializationSequence::AddDerivedToBaseCastStep(QualType BaseType,
bool IsLValue) {
Step S;
S.Kind = IsLValue? SK_CastDerivedToBaseLValue : SK_CastDerivedToBaseRValue;
S.Type = BaseType;
Steps.push_back(S);
}
void InitializationSequence::AddReferenceBindingStep(QualType T,
bool BindingTemporary) {
Step S;
S.Kind = BindingTemporary? SK_BindReferenceToTemporary : SK_BindReference;
S.Type = T;
Steps.push_back(S);
}
void InitializationSequence::AddUserConversionStep(FunctionDecl *Function,
QualType T) {
Step S;
S.Kind = SK_UserConversion;
S.Type = T;
S.Function = Function;
Steps.push_back(S);
}
void InitializationSequence::AddQualificationConversionStep(QualType Ty,
bool IsLValue) {
Step S;
S.Kind = IsLValue? SK_QualificationConversionLValue
: SK_QualificationConversionRValue;
S.Type = Ty;
Steps.push_back(S);
}
void InitializationSequence::AddConversionSequenceStep(
const ImplicitConversionSequence &ICS,
QualType T) {
Step S;
S.Kind = SK_ConversionSequence;
S.Type = T;
S.ICS = new ImplicitConversionSequence(ICS);
Steps.push_back(S);
}
void InitializationSequence::AddListInitializationStep(QualType T) {
Step S;
S.Kind = SK_ListInitialization;
S.Type = T;
Steps.push_back(S);
}
void
InitializationSequence::AddConstructorInitializationStep(
CXXConstructorDecl *Constructor,
QualType T) {
Step S;
S.Kind = SK_ConstructorInitialization;
S.Type = T;
S.Function = Constructor;
Steps.push_back(S);
}
void InitializationSequence::AddZeroInitializationStep(QualType T) {
Step S;
S.Kind = SK_ZeroInitialization;
S.Type = T;
Steps.push_back(S);
}
void InitializationSequence::SetOverloadFailure(FailureKind Failure,
OverloadingResult Result) {
SequenceKind = FailedSequence;
this->Failure = Failure;
this->FailedOverloadResult = Result;
}
//===----------------------------------------------------------------------===//
// Attempt initialization
//===----------------------------------------------------------------------===//
/// \brief Attempt list initialization (C++0x [dcl.init.list])
static void TryListInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
InitListExpr *InitList,
InitializationSequence &Sequence) {
// FIXME: We only perform rudimentary checking of list
// initializations at this point, then assume that any list
// initialization of an array, aggregate, or scalar will be
// well-formed. We we actually "perform" list initialization, we'll
// do all of the necessary checking. C++0x initializer lists will
// force us to perform more checking here.
Sequence.setSequenceKind(InitializationSequence::ListInitialization);
QualType DestType = Entity.getType().getType();
// C++ [dcl.init]p13:
// If T is a scalar type, then a declaration of the form
//
// T x = { a };
//
// is equivalent to
//
// T x = a;
if (DestType->isScalarType()) {
if (InitList->getNumInits() > 1 && S.getLangOptions().CPlusPlus) {
Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForScalar);
return;
}
// Assume scalar initialization from a single value works.
} else if (DestType->isAggregateType()) {
// Assume aggregate initialization works.
} else if (DestType->isVectorType()) {
// Assume vector initialization works.
} else if (DestType->isReferenceType()) {
// FIXME: C++0x defines behavior for this.
Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList);
return;
} else if (DestType->isRecordType()) {
// FIXME: C++0x defines behavior for this
Sequence.SetFailed(InitializationSequence::FK_InitListBadDestinationType);
}
// Add a general "list initialization" step.
Sequence.AddListInitializationStep(DestType);
}
/// \brief Try a reference initialization that involves calling a conversion
/// function.
///
/// FIXME: look intos DRs 656, 896
static OverloadingResult TryRefInitWithConversionFunction(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Expr *Initializer,
bool AllowRValues,
InitializationSequence &Sequence) {
QualType DestType = Entity.getType().getType();
QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType();
QualType T1 = cv1T1.getUnqualifiedType();
QualType cv2T2 = Initializer->getType();
QualType T2 = cv2T2.getUnqualifiedType();
bool DerivedToBase;
assert(!S.CompareReferenceRelationship(Initializer->getLocStart(),
T1, T2, DerivedToBase) &&
"Must have incompatible references when binding via conversion");
(void)DerivedToBase;
// Build the candidate set directly in the initialization sequence
// structure, so that it will persist if we fail.
OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
CandidateSet.clear();
// Determine whether we are allowed to call explicit constructors or
// explicit conversion operators.
bool AllowExplicit = Kind.getKind() == InitializationKind::IK_Direct;
const RecordType *T1RecordType = 0;
if (AllowRValues && (T1RecordType = T1->getAs<RecordType>())) {
// The type we're converting to is a class type. Enumerate its constructors
// to see if there is a suitable conversion.
CXXRecordDecl *T1RecordDecl = cast<CXXRecordDecl>(T1RecordType->getDecl());
DeclarationName ConstructorName
= S.Context.DeclarationNames.getCXXConstructorName(
S.Context.getCanonicalType(T1).getUnqualifiedType());
DeclContext::lookup_iterator Con, ConEnd;
for (llvm::tie(Con, ConEnd) = T1RecordDecl->lookup(ConstructorName);
Con != ConEnd; ++Con) {
// Find the constructor (which may be a template).
CXXConstructorDecl *Constructor = 0;
FunctionTemplateDecl *ConstructorTmpl
= dyn_cast<FunctionTemplateDecl>(*Con);
if (ConstructorTmpl)
Constructor = cast<CXXConstructorDecl>(
ConstructorTmpl->getTemplatedDecl());
else
Constructor = cast<CXXConstructorDecl>(*Con);
if (!Constructor->isInvalidDecl() &&
Constructor->isConvertingConstructor(AllowExplicit)) {
if (ConstructorTmpl)
S.AddTemplateOverloadCandidate(ConstructorTmpl, /*ExplicitArgs*/ 0,
&Initializer, 1, CandidateSet);
else
S.AddOverloadCandidate(Constructor, &Initializer, 1, CandidateSet);
}
}
}
if (const RecordType *T2RecordType = T2->getAs<RecordType>()) {
// The type we're converting from is a class type, enumerate its conversion
// functions.
CXXRecordDecl *T2RecordDecl = cast<CXXRecordDecl>(T2RecordType->getDecl());
// Determine the type we are converting to. If we are allowed to
// convert to an rvalue, take the type that the destination type
// refers to.
QualType ToType = AllowRValues? cv1T1 : DestType;
const UnresolvedSet *Conversions
= T2RecordDecl->getVisibleConversionFunctions();
for (UnresolvedSet::iterator I = Conversions->begin(),
E = Conversions->end();
I != E; ++I) {
NamedDecl *D = *I;
CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
CXXConversionDecl *Conv;
if (ConvTemplate)
Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
else
Conv = cast<CXXConversionDecl>(*I);
// If the conversion function doesn't return a reference type,
// it can't be considered for this conversion unless we're allowed to
// consider rvalues.
// FIXME: Do we need to make sure that we only consider conversion
// candidates with reference-compatible results? That might be needed to
// break recursion.
if ((AllowExplicit || !Conv->isExplicit()) &&
(AllowRValues || Conv->getConversionType()->isLValueReferenceType())){
if (ConvTemplate)
S.AddTemplateConversionCandidate(ConvTemplate, ActingDC, Initializer,
ToType, CandidateSet);
else
S.AddConversionCandidate(Conv, ActingDC, Initializer, cv1T1,
CandidateSet);
}
}
}
SourceLocation DeclLoc = Initializer->getLocStart();
// Perform overload resolution. If it fails, return the failed result.
OverloadCandidateSet::iterator Best;
if (OverloadingResult Result
= S.BestViableFunction(CandidateSet, DeclLoc, Best))
return Result;
FunctionDecl *Function = Best->Function;
// Compute the returned type of the conversion.
if (isa<CXXConversionDecl>(Function))
T2 = Function->getResultType();
else
T2 = cv1T1;
// Add the user-defined conversion step.
Sequence.AddUserConversionStep(Function, T2.getNonReferenceType());
// Determine whether we need to perform derived-to-base or
// cv-qualification adjustments.
bool NewDerivedToBase = false;
Sema::ReferenceCompareResult NewRefRelationship
= S.CompareReferenceRelationship(DeclLoc, T1, T2.getNonReferenceType(),
NewDerivedToBase);
assert(NewRefRelationship != Sema::Ref_Incompatible &&
"Overload resolution picked a bad conversion function");
(void)NewRefRelationship;
if (NewDerivedToBase)
Sequence.AddDerivedToBaseCastStep(
S.Context.getQualifiedType(T1,
T2.getNonReferenceType().getQualifiers()),
/*isLValue=*/true);
if (cv1T1.getQualifiers() != T2.getNonReferenceType().getQualifiers())
Sequence.AddQualificationConversionStep(cv1T1, T2->isReferenceType());
Sequence.AddReferenceBindingStep(cv1T1, !T2->isReferenceType());
return OR_Success;
}
/// \brief Attempt reference initialization (C++0x [dcl.init.list])
static void TryReferenceInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Expr *Initializer,
InitializationSequence &Sequence) {
Sequence.setSequenceKind(InitializationSequence::ReferenceBinding);
QualType DestType = Entity.getType().getType();
QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType();
QualType T1 = cv1T1.getUnqualifiedType();
QualType cv2T2 = Initializer->getType();
QualType T2 = cv2T2.getUnqualifiedType();
SourceLocation DeclLoc = Initializer->getLocStart();
// If the initializer is the address of an overloaded function, try
// to resolve the overloaded function. If all goes well, T2 is the
// type of the resulting function.
if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Initializer,
T1,
false);
if (!Fn) {
Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
return;
}
Sequence.AddAddressOverloadResolutionStep(Fn);
cv2T2 = Fn->getType();
T2 = cv2T2.getUnqualifiedType();
}
// FIXME: Rvalue references
bool ForceRValue = false;
// Compute some basic properties of the types and the initializer.
bool isLValueRef = DestType->isLValueReferenceType();
bool isRValueRef = !isLValueRef;
bool DerivedToBase = false;
Expr::isLvalueResult InitLvalue = ForceRValue ? Expr::LV_InvalidExpression :
Initializer->isLvalue(S.Context);
Sema::ReferenceCompareResult RefRelationship
= S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, DerivedToBase);
// C++0x [dcl.init.ref]p5:
// A reference to type "cv1 T1" is initialized by an expression of type
// "cv2 T2" as follows:
//
// - If the reference is an lvalue reference and the initializer
// expression
OverloadingResult ConvOvlResult = OR_Success;
if (isLValueRef) {
if (InitLvalue == Expr::LV_Valid &&
RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) {
// - is an lvalue (but is not a bit-field), and "cv1 T1" is
// reference-compatible with "cv2 T2," or
//
// Per C++ [over.best.ics]p2, we ignore whether the lvalue is a
// bit-field when we're determining whether the reference initialization
// can occur. This property will be checked by PerformInitialization.
if (DerivedToBase)
Sequence.AddDerivedToBaseCastStep(
S.Context.getQualifiedType(T1, cv2T2.getQualifiers()),
/*isLValue=*/true);
if (cv1T1.getQualifiers() != cv2T2.getQualifiers())
Sequence.AddQualificationConversionStep(cv1T1, /*IsLValue=*/true);
Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/false);
return;
}
// - has a class type (i.e., T2 is a class type), where T1 is not
// reference-related to T2, and can be implicitly converted to an
// lvalue of type "cv3 T3," where "cv1 T1" is reference-compatible
// with "cv3 T3" (this conversion is selected by enumerating the
// applicable conversion functions (13.3.1.6) and choosing the best
// one through overload resolution (13.3)),
if (RefRelationship == Sema::Ref_Incompatible && T2->isRecordType()) {
ConvOvlResult = TryRefInitWithConversionFunction(S, Entity, Kind,
Initializer,
/*AllowRValues=*/false,
Sequence);
if (ConvOvlResult == OR_Success)
return;
}
}
// - Otherwise, the reference shall be an lvalue reference to a
// non-volatile const type (i.e., cv1 shall be const), or the reference
// shall be an rvalue reference and the initializer expression shall
// be an rvalue.
if (!((isLValueRef && cv1T1.getCVRQualifiers() == Qualifiers::Const) ||
(isRValueRef && InitLvalue != Expr::LV_Valid))) {
if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
Sequence.SetOverloadFailure(
InitializationSequence::FK_ReferenceInitOverloadFailed,
ConvOvlResult);
else if (isLValueRef)
Sequence.SetFailed(InitLvalue == Expr::LV_Valid
? (RefRelationship == Sema::Ref_Related
? InitializationSequence::FK_ReferenceInitDropsQualifiers
: InitializationSequence::FK_NonConstLValueReferenceBindingToUnrelated)
: InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary);
else
Sequence.SetFailed(
InitializationSequence::FK_RValueReferenceBindingToLValue);
return;
}
// - If T1 and T2 are class types and
if (T1->isRecordType() && T2->isRecordType()) {
// - the initializer expression is an rvalue and "cv1 T1" is
// reference-compatible with "cv2 T2", or
if (InitLvalue != Expr::LV_Valid &&
RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) {
if (DerivedToBase)
Sequence.AddDerivedToBaseCastStep(
S.Context.getQualifiedType(T1, cv2T2.getQualifiers()),
/*isLValue=*/false);
if (cv1T1.getQualifiers() != cv2T2.getQualifiers())
Sequence.AddQualificationConversionStep(cv1T1, /*IsLValue=*/false);
Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true);
return;
}
// - T1 is not reference-related to T2 and the initializer expression
// can be implicitly converted to an rvalue of type "cv3 T3" (this
// conversion is selected by enumerating the applicable conversion
// functions (13.3.1.6) and choosing the best one through overload
// resolution (13.3)),
if (RefRelationship == Sema::Ref_Incompatible) {
ConvOvlResult = TryRefInitWithConversionFunction(S, Entity,
Kind, Initializer,
/*AllowRValues=*/true,
Sequence);
if (ConvOvlResult)
Sequence.SetOverloadFailure(
InitializationSequence::FK_ReferenceInitOverloadFailed,
ConvOvlResult);
return;
}
Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
return;
}
// - If the initializer expression is an rvalue, with T2 an array type,
// and "cv1 T1" is reference-compatible with "cv2 T2," the reference
// is bound to the object represented by the rvalue (see 3.10).
// FIXME: How can an array type be reference-compatible with anything?
// Don't we mean the element types of T1 and T2?
// - Otherwise, a temporary of type “cv1 T1” is created and initialized
// from the initializer expression using the rules for a non-reference
// copy initialization (8.5). The reference is then bound to the
// temporary. [...]
// Determine whether we are allowed to call explicit constructors or
// explicit conversion operators.
bool AllowExplicit = (Kind.getKind() == InitializationKind::IK_Direct);
ImplicitConversionSequence ICS
= S.TryImplicitConversion(Initializer, cv1T1,
/*SuppressUserConversions=*/false, AllowExplicit,
/*ForceRValue=*/false,
/*FIXME:InOverloadResolution=*/false,
/*UserCast=*/Kind.isExplicitCast());
if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) {
// FIXME: Use the conversion function set stored in ICS to turn
// this into an overloading ambiguity diagnostic. However, we need
// to keep that set as an OverloadCandidateSet rather than as some
// other kind of set.
Sequence.SetFailed(InitializationSequence::FK_ReferenceInitFailed);
return;
}
// [...] If T1 is reference-related to T2, cv1 must be the
// same cv-qualification as, or greater cv-qualification
// than, cv2; otherwise, the program is ill-formed.
if (RefRelationship == Sema::Ref_Related &&
!cv1T1.isAtLeastAsQualifiedAs(cv2T2)) {
Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
return;
}
// Perform the actual conversion.
Sequence.AddConversionSequenceStep(ICS, cv1T1);
Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true);
return;
}
/// \brief Attempt character array initialization from a string literal
/// (C++ [dcl.init.string], C99 6.7.8).
static void TryStringLiteralInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Expr *Initializer,
InitializationSequence &Sequence) {
// FIXME: Implement!
}
/// \brief Attempt initialization by constructor (C++ [dcl.init]), which
/// enumerates the constructors of the initialized entity and performs overload
/// resolution to select the best.
static void TryConstructorInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Expr **Args, unsigned NumArgs,
QualType DestType,
InitializationSequence &Sequence) {
Sequence.setSequenceKind(InitializationSequence::ConstructorInitialization);
// Build the candidate set directly in the initialization sequence
// structure, so that it will persist if we fail.
OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
CandidateSet.clear();
// Determine whether we are allowed to call explicit constructors or
// explicit conversion operators.
bool AllowExplicit = (Kind.getKind() == InitializationKind::IK_Direct ||
Kind.getKind() == InitializationKind::IK_Value ||
Kind.getKind() == InitializationKind::IK_Default);
// The type we're converting to is a class type. Enumerate its constructors
// to see if one is suitable.
const RecordType *DestRecordType = DestType->getAs<RecordType>();
assert(DestRecordType && "Constructor initialization requires record type");
CXXRecordDecl *DestRecordDecl
= cast<CXXRecordDecl>(DestRecordType->getDecl());
DeclarationName ConstructorName
= S.Context.DeclarationNames.getCXXConstructorName(
S.Context.getCanonicalType(DestType).getUnqualifiedType());
DeclContext::lookup_iterator Con, ConEnd;
for (llvm::tie(Con, ConEnd) = DestRecordDecl->lookup(ConstructorName);
Con != ConEnd; ++Con) {
// Find the constructor (which may be a template).
CXXConstructorDecl *Constructor = 0;
FunctionTemplateDecl *ConstructorTmpl
= dyn_cast<FunctionTemplateDecl>(*Con);
if (ConstructorTmpl)
Constructor = cast<CXXConstructorDecl>(
ConstructorTmpl->getTemplatedDecl());
else
Constructor = cast<CXXConstructorDecl>(*Con);
if (!Constructor->isInvalidDecl() &&
Constructor->isConvertingConstructor(AllowExplicit)) {
if (ConstructorTmpl)
S.AddTemplateOverloadCandidate(ConstructorTmpl, /*ExplicitArgs*/ 0,
Args, NumArgs, CandidateSet);
else
S.AddOverloadCandidate(Constructor, Args, NumArgs, CandidateSet);
}
}
SourceLocation DeclLoc = Kind.getLocation();
// Perform overload resolution. If it fails, return the failed result.
OverloadCandidateSet::iterator Best;
if (OverloadingResult Result
= S.BestViableFunction(CandidateSet, DeclLoc, Best)) {
Sequence.SetOverloadFailure(
InitializationSequence::FK_ConstructorOverloadFailed,
Result);
return;
}
// Add the constructor initialization step. Any cv-qualification conversion is
// subsumed by the initialization.
Sequence.AddConstructorInitializationStep(
cast<CXXConstructorDecl>(Best->Function),
DestType);
}
/// \brief Attempt value initialization (C++ [dcl.init]p7).
static void TryValueInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
InitializationSequence &Sequence) {
// C++ [dcl.init]p5:
//
// To value-initialize an object of type T means:
QualType T = Entity.getType().getType();
// -- if T is an array type, then each element is value-initialized;
while (const ArrayType *AT = S.Context.getAsArrayType(T))
T = AT->getElementType();
if (const RecordType *RT = T->getAs<RecordType>()) {
if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
// -- if T is a class type (clause 9) with a user-declared
// constructor (12.1), then the default constructor for T is
// called (and the initialization is ill-formed if T has no
// accessible default constructor);
//
// FIXME: we really want to refer to a single subobject of the array,
// but Entity doesn't have a way to capture that (yet).
if (ClassDecl->hasUserDeclaredConstructor())
return TryConstructorInitialization(S, Entity, Kind, 0, 0, T, Sequence);
// FIXME: non-union class type w/ non-trivial default constructor gets
// zero-initialized, then constructor gets called.
}
}
Sequence.AddZeroInitializationStep(Entity.getType().getType());
Sequence.setSequenceKind(InitializationSequence::ZeroInitialization);
}
/// \brief Attempt a user-defined conversion between two types (C++ [dcl.init]),
/// which enumerates all conversion functions and performs overload resolution
/// to select the best.
static void TryUserDefinedConversion(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Expr *Initializer,
InitializationSequence &Sequence) {
Sequence.setSequenceKind(InitializationSequence::UserDefinedConversion);
QualType DestType = Entity.getType().getType();
assert(!DestType->isReferenceType() && "References are handled elsewhere");
QualType SourceType = Initializer->getType();
assert((DestType->isRecordType() || SourceType->isRecordType()) &&
"Must have a class type to perform a user-defined conversion");
// Build the candidate set directly in the initialization sequence
// structure, so that it will persist if we fail.
OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
CandidateSet.clear();
// Determine whether we are allowed to call explicit constructors or
// explicit conversion operators.
bool AllowExplicit = Kind.getKind() == InitializationKind::IK_Direct;
if (const RecordType *DestRecordType = DestType->getAs<RecordType>()) {
// The type we're converting to is a class type. Enumerate its constructors
// to see if there is a suitable conversion.
CXXRecordDecl *DestRecordDecl
= cast<CXXRecordDecl>(DestRecordType->getDecl());
DeclarationName ConstructorName
= S.Context.DeclarationNames.getCXXConstructorName(
S.Context.getCanonicalType(DestType).getUnqualifiedType());
DeclContext::lookup_iterator Con, ConEnd;
for (llvm::tie(Con, ConEnd) = DestRecordDecl->lookup(ConstructorName);
Con != ConEnd; ++Con) {
// Find the constructor (which may be a template).
CXXConstructorDecl *Constructor = 0;
FunctionTemplateDecl *ConstructorTmpl
= dyn_cast<FunctionTemplateDecl>(*Con);
if (ConstructorTmpl)
Constructor = cast<CXXConstructorDecl>(
ConstructorTmpl->getTemplatedDecl());
else
Constructor = cast<CXXConstructorDecl>(*Con);
if (!Constructor->isInvalidDecl() &&
Constructor->isConvertingConstructor(AllowExplicit)) {
if (ConstructorTmpl)
S.AddTemplateOverloadCandidate(ConstructorTmpl, /*ExplicitArgs*/ 0,
&Initializer, 1, CandidateSet);
else
S.AddOverloadCandidate(Constructor, &Initializer, 1, CandidateSet);
}
}
}
if (const RecordType *SourceRecordType = SourceType->getAs<RecordType>()) {
// The type we're converting from is a class type, enumerate its conversion
// functions.
CXXRecordDecl *SourceRecordDecl
= cast<CXXRecordDecl>(SourceRecordType->getDecl());
const UnresolvedSet *Conversions
= SourceRecordDecl->getVisibleConversionFunctions();
for (UnresolvedSet::iterator I = Conversions->begin(),
E = Conversions->end();
I != E; ++I) {
NamedDecl *D = *I;
CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
CXXConversionDecl *Conv;
if (ConvTemplate)
Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
else
Conv = cast<CXXConversionDecl>(*I);
if (AllowExplicit || !Conv->isExplicit()) {
if (ConvTemplate)
S.AddTemplateConversionCandidate(ConvTemplate, ActingDC, Initializer,
DestType, CandidateSet);
else
S.AddConversionCandidate(Conv, ActingDC, Initializer, DestType,
CandidateSet);
}
}
}
SourceLocation DeclLoc = Initializer->getLocStart();
// Perform overload resolution. If it fails, return the failed result.
OverloadCandidateSet::iterator Best;
if (OverloadingResult Result
= S.BestViableFunction(CandidateSet, DeclLoc, Best)) {
Sequence.SetOverloadFailure(
InitializationSequence::FK_UserConversionOverloadFailed,
Result);
return;
}
FunctionDecl *Function = Best->Function;
if (isa<CXXConstructorDecl>(Function)) {
// Add the user-defined conversion step. Any cv-qualification conversion is
// subsumed by the initialization.
Sequence.AddUserConversionStep(Function, DestType);
return;
}
// Add the user-defined conversion step that calls the conversion function.
QualType ConvType = Function->getResultType().getNonReferenceType();
Sequence.AddUserConversionStep(Function, ConvType);
// If the conversion following the call to the conversion function is
// interesting, add it as a separate step.
if (Best->FinalConversion.First || Best->FinalConversion.Second ||
Best->FinalConversion.Third) {
ImplicitConversionSequence ICS;
ICS.ConversionKind = ImplicitConversionSequence::StandardConversion;
ICS.Standard = Best->FinalConversion;
Sequence.AddConversionSequenceStep(ICS, DestType);
}
}
/// \brief Attempt an implicit conversion (C++ [conv]) converting from one
/// non-class type to another.
static void TryImplicitConversion(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Expr *Initializer,
InitializationSequence &Sequence) {
ImplicitConversionSequence ICS
= S.TryImplicitConversion(Initializer, Entity.getType().getType(),
/*SuppressUserConversions=*/true,
/*AllowExplicit=*/false,
/*ForceRValue=*/false,
/*FIXME:InOverloadResolution=*/false,
/*UserCast=*/Kind.isExplicitCast());
if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) {
Sequence.SetFailed(InitializationSequence::FK_ConversionFailed);
return;
}
Sequence.AddConversionSequenceStep(ICS, Entity.getType().getType());
}
InitializationSequence::InitializationSequence(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Expr **Args,
unsigned NumArgs) {
ASTContext &Context = S.Context;
// C++0x [dcl.init]p16:
// The semantics of initializers are as follows. The destination type is
// the type of the object or reference being initialized and the source
// type is the type of the initializer expression. The source type is not
// defined when the initializer is a braced-init-list or when it is a
// parenthesized list of expressions.
QualType DestType = Entity.getType().getType();
if (DestType->isDependentType() ||
Expr::hasAnyTypeDependentArguments(Args, NumArgs)) {
SequenceKind = DependentSequence;
return;
}
QualType SourceType;
Expr *Initializer = 0;
if (Kind.getKind() == InitializationKind::IK_Copy) {
Initializer = Args[0];
if (!isa<InitListExpr>(Initializer))
SourceType = Initializer->getType();
}
// - If the initializer is a braced-init-list, the object is
// list-initialized (8.5.4).
if (InitListExpr *InitList = dyn_cast_or_null<InitListExpr>(Initializer)) {
TryListInitialization(S, Entity, Kind, InitList, *this);
return;
}
// - If the destination type is a reference type, see 8.5.3.
if (DestType->isReferenceType()) {
// C++0x [dcl.init.ref]p1:
// A variable declared to be a T& or T&&, that is, "reference to type T"
// (8.3.2), shall be initialized by an object, or function, of type T or
// by an object that can be converted into a T.
// (Therefore, multiple arguments are not permitted.)
if (NumArgs != 1)
SetFailed(FK_TooManyInitsForReference);
else
TryReferenceInitialization(S, Entity, Kind, Args[0], *this);
return;
}
// - If the destination type is an array of characters, an array of
// char16_t, an array of char32_t, or an array of wchar_t, and the
// initializer is a string literal, see 8.5.2.
if (Initializer && IsStringInit(Initializer, DestType, Context)) {
TryStringLiteralInitialization(S, Entity, Kind, Initializer, *this);
return;
}
// - If the initializer is (), the object is value-initialized.
if (Kind.getKind() == InitializationKind::IK_Value) {
TryValueInitialization(S, Entity, Kind, *this);
return;
}
// - Otherwise, if the destination type is an array, the program is
// ill-formed.
if (const ArrayType *AT = Context.getAsArrayType(DestType)) {
if (AT->getElementType()->isAnyCharacterType())
SetFailed(FK_ArrayNeedsInitListOrStringLiteral);
else
SetFailed(FK_ArrayNeedsInitList);
return;
}
// - If the destination type is a (possibly cv-qualified) class type:
if (DestType->isRecordType()) {
// - If the initialization is direct-initialization, or if it is
// copy-initialization where the cv-unqualified version of the
// source type is the same class as, or a derived class of, the
// class of the destination, constructors are considered. [...]
if (Kind.getKind() == InitializationKind::IK_Direct ||
(Kind.getKind() == InitializationKind::IK_Copy &&
(Context.hasSameUnqualifiedType(SourceType, DestType) ||
S.IsDerivedFrom(SourceType, DestType))))
TryConstructorInitialization(S, Entity, Kind, Args, NumArgs,
Entity.getType().getType(), *this);
// - Otherwise (i.e., for the remaining copy-initialization cases),
// user-defined conversion sequences that can convert from the source
// type to the destination type or (when a conversion function is
// used) to a derived class thereof are enumerated as described in
// 13.3.1.4, and the best one is chosen through overload resolution
// (13.3).
else
TryUserDefinedConversion(S, Entity, Kind, Initializer, *this);
return;
}
// - Otherwise, if the source type is a (possibly cv-qualified) class
// type, conversion functions are considered.
if (SourceType->isRecordType()) {
TryUserDefinedConversion(S, Entity, Kind, Initializer, *this);
return;
}
// - Otherwise, the initial value of the object being initialized is the
// (possibly converted) value of the initializer expression. Standard
// conversions (Clause 4) will be used, if necessary, to convert the
// initializer expression to the cv-unqualified version of the
// destination type; no user-defined conversions are considered.
TryImplicitConversion(S, Entity, Kind, Initializer, *this);
}
InitializationSequence::~InitializationSequence() {
for (llvm::SmallVectorImpl<Step>::iterator Step = Steps.begin(),
StepEnd = Steps.end();
Step != StepEnd; ++Step)
Step->Destroy();
}
//===----------------------------------------------------------------------===//
// Perform initialization
//===----------------------------------------------------------------------===//
Action::OwningExprResult
InitializationSequence::Perform(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Action::MultiExprArg Args,
QualType *ResultType) {
if (SequenceKind == FailedSequence) {
unsigned NumArgs = Args.size();
Diagnose(S, Entity, Kind, (Expr **)Args.release(), NumArgs);
return S.ExprError();
}
if (SequenceKind == DependentSequence) {
// If the declaration is a non-dependent, incomplete array type
// that has an initializer, then its type will be completed once
// the initializer is instantiated.
if (ResultType && !Entity.getType().getType()->isDependentType() &&
Args.size() == 1) {
QualType DeclType = Entity.getType().getType();
if (const IncompleteArrayType *ArrayT
= S.Context.getAsIncompleteArrayType(DeclType)) {
// FIXME: We don't currently have the ability to accurately
// compute the length of an initializer list without
// performing full type-checking of the initializer list
// (since we have to determine where braces are implicitly
// introduced and such). So, we fall back to making the array
// type a dependently-sized array type with no specified
// bound.
if (isa<InitListExpr>((Expr *)Args.get()[0])) {
SourceRange Brackets;
// Scavange the location of the brackets from the entity, if we can.
if (isa<IncompleteArrayTypeLoc>(Entity.getType())) {
IncompleteArrayTypeLoc ArrayLoc
= cast<IncompleteArrayTypeLoc>(Entity.getType());
Brackets = ArrayLoc.getBracketsRange();
}
*ResultType
= S.Context.getDependentSizedArrayType(ArrayT->getElementType(),
/*NumElts=*/0,
ArrayT->getSizeModifier(),
ArrayT->getIndexTypeCVRQualifiers(),
Brackets);
}
}
}
if (Kind.getKind() == InitializationKind::IK_Copy)
return Sema::OwningExprResult(S, Args.release()[0]);
unsigned NumArgs = Args.size();
return S.Owned(new (S.Context) ParenListExpr(S.Context,
SourceLocation(),
(Expr **)Args.release(),
NumArgs,
SourceLocation()));
}
QualType DestType = Entity.getType().getType().getNonReferenceType();
if (ResultType)
*ResultType = Entity.getType().getType();
Sema::OwningExprResult CurInit(S);
// For copy initialization and any other initialization forms that
// only have a single initializer, we start with the (only)
// initializer we have.
// FIXME: DPG is not happy about this. There's confusion regarding whether
// we're supposed to start the conversion from the solitary initializer or
// from the set of arguments.
if (Kind.getKind() == InitializationKind::IK_Copy ||
SequenceKind != ConstructorInitialization) {
assert(Args.size() == 1);
CurInit = Sema::OwningExprResult(S, Args.release()[0]);
if (CurInit.isInvalid())
return S.ExprError();
}
// Walk through the computed steps for the initialization sequence,
// performing the specified conversions along the way.
for (step_iterator Step = step_begin(), StepEnd = step_end();
Step != StepEnd; ++Step) {
if (CurInit.isInvalid())
return S.ExprError();
Expr *CurInitExpr = (Expr *)CurInit.get();
QualType SourceType = CurInitExpr->getType();
switch (Step->Kind) {
case SK_ResolveAddressOfOverloadedFunction:
// Overload resolution determined which function invoke; update the
// initializer to reflect that choice.
CurInit = S.FixOverloadedFunctionReference(move(CurInit), Step->Function);
break;
case SK_CastDerivedToBaseRValue:
case SK_CastDerivedToBaseLValue: {
// We have a derived-to-base cast that produces either an rvalue or an
// lvalue. Perform that cast.
// Casts to inaccessible base classes are allowed with C-style casts.
bool IgnoreBaseAccess = Kind.isCStyleOrFunctionalCast();
if (S.CheckDerivedToBaseConversion(SourceType, Step->Type,
CurInitExpr->getLocStart(),
CurInitExpr->getSourceRange(),
IgnoreBaseAccess))
return S.ExprError();
CurInit = S.Owned(new (S.Context) ImplicitCastExpr(Step->Type,
CastExpr::CK_DerivedToBase,
(Expr*)CurInit.release(),
Step->Kind == SK_CastDerivedToBaseLValue));
break;
}
case SK_BindReference:
if (FieldDecl *BitField = CurInitExpr->getBitField()) {
// References cannot bind to bit fields (C++ [dcl.init.ref]p5).
S.Diag(Kind.getLocation(), diag::err_reference_bind_to_bitfield)
<< Entity.getType().getType().isVolatileQualified()
<< BitField->getDeclName()
<< CurInitExpr->getSourceRange();
S.Diag(BitField->getLocation(), diag::note_bitfield_decl);
return S.ExprError();
}
// Reference binding does not have any corresponding ASTs.
// Check exception specifications
if (S.CheckExceptionSpecCompatibility(CurInitExpr, DestType))
return S.ExprError();
break;
case SK_BindReferenceToTemporary:
// Check exception specifications
if (S.CheckExceptionSpecCompatibility(CurInitExpr, DestType))
return S.ExprError();
// FIXME: At present, we have no AST to describe when we need to make a
// temporary to bind a reference to. We should.
break;
case SK_UserConversion: {
// We have a user-defined conversion that invokes either a constructor
// or a conversion function.
CastExpr::CastKind CastKind = CastExpr::CK_Unknown;
if (CXXConstructorDecl *Constructor
= dyn_cast<CXXConstructorDecl>(Step->Function)) {
// Build a call to the selected constructor.
ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(S);
SourceLocation Loc = CurInitExpr->getLocStart();
CurInit.release(); // Ownership transferred into MultiExprArg, below.
// Determine the arguments required to actually perform the constructor
// call.
if (S.CompleteConstructorCall(Constructor,
Sema::MultiExprArg(S,
(void **)&CurInitExpr,
1),
Loc, ConstructorArgs))
return S.ExprError();
// Build the an expression that constructs a temporary.
CurInit = S.BuildCXXConstructExpr(Loc, Step->Type, Constructor,
move_arg(ConstructorArgs));
if (CurInit.isInvalid())
return S.ExprError();
CastKind = CastExpr::CK_ConstructorConversion;
} else {
// Build a call to the conversion function.
CXXConversionDecl *Conversion = cast<CXXConversionDecl>(Step->Function);
// FIXME: Should we move this initialization into a separate
// derived-to-base conversion? I believe the answer is "no", because
// we don't want to turn off access control here for c-style casts.
if (S.PerformObjectArgumentInitialization(CurInitExpr, Conversion))
return S.ExprError();
// Do a little dance to make sure that CurInit has the proper
// pointer.
CurInit.release();
// Build the actual call to the conversion function.
CurInit = S.Owned(S.BuildCXXMemberCallExpr(CurInitExpr, Conversion));
if (CurInit.isInvalid() || !CurInit.get())
return S.ExprError();
CastKind = CastExpr::CK_UserDefinedConversion;
}
CurInit = S.MaybeBindToTemporary(CurInit.takeAs<Expr>());
CurInitExpr = CurInit.takeAs<Expr>();
CurInit = S.Owned(new (S.Context) ImplicitCastExpr(CurInitExpr->getType(),
CastKind,
CurInitExpr,
false));
break;
}
case SK_QualificationConversionLValue:
case SK_QualificationConversionRValue:
// Perform a qualification conversion; these can never go wrong.
S.ImpCastExprToType(CurInitExpr, Step->Type,
CastExpr::CK_NoOp,
Step->Kind == SK_QualificationConversionLValue);
CurInit.release();
CurInit = S.Owned(CurInitExpr);
break;
case SK_ConversionSequence:
if (S.PerformImplicitConversion(CurInitExpr, Step->Type, "converting",
false, false, *Step->ICS))
return S.ExprError();
CurInit.release();
CurInit = S.Owned(CurInitExpr);
break;
case SK_ListInitialization: {
InitListExpr *InitList = cast<InitListExpr>(CurInitExpr);
QualType Ty = Step->Type;
if (S.CheckInitList(InitList, ResultType? *ResultType : Ty))
return S.ExprError();
CurInit.release();
CurInit = S.Owned(InitList);
break;
}
case SK_ConstructorInitialization: {
CXXConstructorDecl *Constructor
= cast<CXXConstructorDecl>(Step->Function);
// Build a call to the selected constructor.
ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(S);
SourceLocation Loc = Kind.getLocation();
// Determine the arguments required to actually perform the constructor
// call.
if (S.CompleteConstructorCall(Constructor, move(Args),
Loc, ConstructorArgs))
return S.ExprError();
// Build the an expression that constructs a temporary.
CurInit = S.BuildCXXConstructExpr(Loc, Step->Type, Constructor,
move_arg(ConstructorArgs));
if (CurInit.isInvalid())
return S.ExprError();
CurInit = S.MaybeBindToTemporary(CurInit.takeAs<Expr>());
break;
}
case SK_ZeroInitialization: {
if (Kind.getKind() == InitializationKind::IK_Value)
CurInit = S.Owned(new (S.Context) CXXZeroInitValueExpr(Step->Type,
Kind.getRange().getBegin(),
Kind.getRange().getEnd()));
else
CurInit = S.Owned(new (S.Context) ImplicitValueInitExpr(Step->Type));
break;
}
}
}
return move(CurInit);
}
//===----------------------------------------------------------------------===//
// Diagnose initialization failures
//===----------------------------------------------------------------------===//
bool InitializationSequence::Diagnose(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Expr **Args, unsigned NumArgs) {
if (SequenceKind != FailedSequence)
return false;
QualType DestType = Entity.getType().getType();
switch (Failure) {
case FK_TooManyInitsForReference:
S.Diag(Kind.getLocation(), diag::err_reference_has_multiple_inits)
<< SourceRange(Args[0]->getLocStart(), Args[NumArgs - 1]->getLocEnd());
break;
case FK_ArrayNeedsInitList:
case FK_ArrayNeedsInitListOrStringLiteral:
S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list)
<< (Failure == FK_ArrayNeedsInitListOrStringLiteral);
break;
case FK_AddressOfOverloadFailed:
S.ResolveAddressOfOverloadedFunction(Args[0],
DestType.getNonReferenceType(),
true);
break;
case FK_ReferenceInitOverloadFailed:
case FK_UserConversionOverloadFailed:
switch (FailedOverloadResult) {
case OR_Ambiguous:
S.Diag(Kind.getLocation(), diag::err_typecheck_ambiguous_condition)
<< Args[0]->getType() << DestType.getNonReferenceType()
<< Args[0]->getSourceRange();
S.PrintOverloadCandidates(FailedCandidateSet, true);
break;
case OR_No_Viable_Function:
S.Diag(Kind.getLocation(), diag::err_typecheck_nonviable_condition)
<< Args[0]->getType() << DestType.getNonReferenceType()
<< Args[0]->getSourceRange();
S.PrintOverloadCandidates(FailedCandidateSet, false);
break;
case OR_Deleted: {
S.Diag(Kind.getLocation(), diag::err_typecheck_deleted_function)
<< Args[0]->getType() << DestType.getNonReferenceType()
<< Args[0]->getSourceRange();
OverloadCandidateSet::iterator Best;
OverloadingResult Ovl = S.BestViableFunction(FailedCandidateSet,
Kind.getLocation(),
Best);
if (Ovl == OR_Deleted) {
S.Diag(Best->Function->getLocation(), diag::note_unavailable_here)
<< Best->Function->isDeleted();
} else {
llvm_unreachable("Inconsistent overload resolution?");
}
break;
}
case OR_Success:
llvm_unreachable("Conversion did not fail!");
break;
}
break;
case FK_NonConstLValueReferenceBindingToTemporary:
case FK_NonConstLValueReferenceBindingToUnrelated:
S.Diag(Kind.getLocation(),
Failure == FK_NonConstLValueReferenceBindingToTemporary
? diag::err_lvalue_reference_bind_to_temporary
: diag::err_lvalue_reference_bind_to_unrelated)
<< DestType.getNonReferenceType()
<< Args[0]->getType()
<< Args[0]->getSourceRange();
break;
case FK_RValueReferenceBindingToLValue:
S.Diag(Kind.getLocation(), diag::err_lvalue_to_rvalue_ref)
<< Args[0]->getSourceRange();
break;
case FK_ReferenceInitDropsQualifiers:
S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
<< DestType.getNonReferenceType()
<< Args[0]->getType()
<< Args[0]->getSourceRange();
break;
case FK_ReferenceInitFailed:
S.Diag(Kind.getLocation(), diag::err_reference_bind_failed)
<< DestType.getNonReferenceType()
<< (Args[0]->isLvalue(S.Context) == Expr::LV_Valid)
<< Args[0]->getType()
<< Args[0]->getSourceRange();
break;
case FK_ConversionFailed:
S.Diag(Kind.getLocation(), diag::err_cannot_initialize_decl_noname)
<< DestType
<< (Args[0]->isLvalue(S.Context) == Expr::LV_Valid)
<< Args[0]->getType()
<< Args[0]->getSourceRange();
break;
case FK_TooManyInitsForScalar: {
InitListExpr *InitList = cast<InitListExpr>(Args[0]);
S.Diag(Kind.getLocation(), diag::err_excess_initializers)
<< /*scalar=*/2
<< SourceRange(InitList->getInit(1)->getLocStart(),
InitList->getLocEnd());
break;
}
case FK_ReferenceBindingToInitList:
S.Diag(Kind.getLocation(), diag::err_reference_bind_init_list)
<< DestType.getNonReferenceType() << Args[0]->getSourceRange();
break;
case FK_InitListBadDestinationType:
S.Diag(Kind.getLocation(), diag::err_init_list_bad_dest_type)
<< (DestType->isRecordType()) << DestType << Args[0]->getSourceRange();
break;
case FK_ConstructorOverloadFailed: {
SourceRange ArgsRange;
if (NumArgs)
ArgsRange = SourceRange(Args[0]->getLocStart(),
Args[NumArgs - 1]->getLocEnd());
// FIXME: Using "DestType" for the entity we're printing is probably
// bad.
switch (FailedOverloadResult) {
case OR_Ambiguous:
S.Diag(Kind.getLocation(), diag::err_ovl_ambiguous_init)
<< DestType << ArgsRange;
S.PrintOverloadCandidates(FailedCandidateSet, true);
break;
case OR_No_Viable_Function:
S.Diag(Kind.getLocation(), diag::err_ovl_no_viable_function_in_init)
<< DestType << ArgsRange;
S.PrintOverloadCandidates(FailedCandidateSet, false);
break;
case OR_Deleted: {
S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init)
<< true << DestType << ArgsRange;
OverloadCandidateSet::iterator Best;
OverloadingResult Ovl = S.BestViableFunction(FailedCandidateSet,
Kind.getLocation(),
Best);
if (Ovl == OR_Deleted) {
S.Diag(Best->Function->getLocation(), diag::note_unavailable_here)
<< Best->Function->isDeleted();
} else {
llvm_unreachable("Inconsistent overload resolution?");
}
break;
}
case OR_Success:
llvm_unreachable("Conversion did not fail!");
break;
}
break;
}
}
return true;
}