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llvm-project/clang/lib/Sema/SemaExprMember.cpp

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//===--- SemaExprMember.cpp - Semantic Analysis for Expressions -----------===//
//
// 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 member access expressions.
//
//===----------------------------------------------------------------------===//
#include "clang/Sema/SemaInternal.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/Scope.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "clang/Lex/Preprocessor.h"
using namespace clang;
using namespace sema;
/// Determines if the given class is provably not derived from all of
/// the prospective base classes.
static bool IsProvablyNotDerivedFrom(Sema &SemaRef,
CXXRecordDecl *Record,
const llvm::SmallPtrSet<CXXRecordDecl*, 4> &Bases) {
if (Bases.count(Record->getCanonicalDecl()))
return false;
RecordDecl *RD = Record->getDefinition();
if (!RD) return false;
Record = cast<CXXRecordDecl>(RD);
for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(),
E = Record->bases_end(); I != E; ++I) {
CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType());
CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>();
if (!BaseRT) return false;
CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl());
if (!IsProvablyNotDerivedFrom(SemaRef, BaseRecord, Bases))
return false;
}
return true;
}
enum IMAKind {
/// The reference is definitely not an instance member access.
IMA_Static,
/// The reference may be an implicit instance member access.
IMA_Mixed,
/// The reference may be to an instance member, but it is invalid if
/// so, because the context is not an instance method.
IMA_Mixed_StaticContext,
/// The reference may be to an instance member, but it is invalid if
/// so, because the context is from an unrelated class.
IMA_Mixed_Unrelated,
/// The reference is definitely an implicit instance member access.
IMA_Instance,
/// The reference may be to an unresolved using declaration.
IMA_Unresolved,
/// The reference may be to an unresolved using declaration and the
/// context is not an instance method.
IMA_Unresolved_StaticContext,
/// All possible referrents are instance members and the current
/// context is not an instance method.
IMA_Error_StaticContext,
/// All possible referrents are instance members of an unrelated
/// class.
IMA_Error_Unrelated
};
/// The given lookup names class member(s) and is not being used for
/// an address-of-member expression. Classify the type of access
/// according to whether it's possible that this reference names an
/// instance member. This is best-effort; it is okay to
/// conservatively answer "yes", in which case some errors will simply
/// not be caught until template-instantiation.
static IMAKind ClassifyImplicitMemberAccess(Sema &SemaRef,
Scope *CurScope,
const LookupResult &R) {
assert(!R.empty() && (*R.begin())->isCXXClassMember());
DeclContext *DC = SemaRef.getFunctionLevelDeclContext();
bool isStaticContext =
(!isa<CXXMethodDecl>(DC) ||
cast<CXXMethodDecl>(DC)->isStatic());
// C++0x [expr.prim]p4:
// Otherwise, if a member-declarator declares a non-static data member
// of a class X, the expression this is a prvalue of type "pointer to X"
// within the optional brace-or-equal-initializer.
if (CurScope->getFlags() & Scope::ThisScope)
isStaticContext = false;
if (R.isUnresolvableResult())
return isStaticContext ? IMA_Unresolved_StaticContext : IMA_Unresolved;
// Collect all the declaring classes of instance members we find.
bool hasNonInstance = false;
bool hasField = false;
llvm::SmallPtrSet<CXXRecordDecl*, 4> Classes;
for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
NamedDecl *D = *I;
if (D->isCXXInstanceMember()) {
if (dyn_cast<FieldDecl>(D))
hasField = true;
CXXRecordDecl *R = cast<CXXRecordDecl>(D->getDeclContext());
Classes.insert(R->getCanonicalDecl());
}
else
hasNonInstance = true;
}
// If we didn't find any instance members, it can't be an implicit
// member reference.
if (Classes.empty())
return IMA_Static;
// If the current context is not an instance method, it can't be
// an implicit member reference.
if (isStaticContext) {
if (hasNonInstance)
return IMA_Mixed_StaticContext;
if (SemaRef.getLangOptions().CPlusPlus0x && hasField) {
// C++0x [expr.prim.general]p10:
// An id-expression that denotes a non-static data member or non-static
// member function of a class can only be used:
// (...)
// - if that id-expression denotes a non-static data member and it
// appears in an unevaluated operand.
const Sema::ExpressionEvaluationContextRecord& record
= SemaRef.ExprEvalContexts.back();
bool isUnevaluatedExpression = (record.Context == Sema::Unevaluated);
if (isUnevaluatedExpression)
return IMA_Mixed_StaticContext;
}
return IMA_Error_StaticContext;
}
CXXRecordDecl *contextClass;
if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC))
contextClass = MD->getParent()->getCanonicalDecl();
else
contextClass = cast<CXXRecordDecl>(DC);
// [class.mfct.non-static]p3:
// ...is used in the body of a non-static member function of class X,
// if name lookup (3.4.1) resolves the name in the id-expression to a
// non-static non-type member of some class C [...]
// ...if C is not X or a base class of X, the class member access expression
// is ill-formed.
if (R.getNamingClass() &&
contextClass != R.getNamingClass()->getCanonicalDecl() &&
contextClass->isProvablyNotDerivedFrom(R.getNamingClass()))
return (hasNonInstance ? IMA_Mixed_Unrelated : IMA_Error_Unrelated);
// If we can prove that the current context is unrelated to all the
// declaring classes, it can't be an implicit member reference (in
// which case it's an error if any of those members are selected).
if (IsProvablyNotDerivedFrom(SemaRef, contextClass, Classes))
return (hasNonInstance ? IMA_Mixed_Unrelated : IMA_Error_Unrelated);
return (hasNonInstance ? IMA_Mixed : IMA_Instance);
}
/// Diagnose a reference to a field with no object available.
static void DiagnoseInstanceReference(Sema &SemaRef,
const CXXScopeSpec &SS,
NamedDecl *rep,
const DeclarationNameInfo &nameInfo) {
SourceLocation Loc = nameInfo.getLoc();
SourceRange Range(Loc);
if (SS.isSet()) Range.setBegin(SS.getRange().getBegin());
if (isa<FieldDecl>(rep) || isa<IndirectFieldDecl>(rep)) {
if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(SemaRef.CurContext)) {
if (MD->isStatic()) {
// "invalid use of member 'x' in static member function"
SemaRef.Diag(Loc, diag::err_invalid_member_use_in_static_method)
<< Range << nameInfo.getName();
return;
}
}
SemaRef.Diag(Loc, diag::err_invalid_non_static_member_use)
<< nameInfo.getName() << Range;
return;
}
SemaRef.Diag(Loc, diag::err_member_call_without_object) << Range;
}
/// Builds an expression which might be an implicit member expression.
ExprResult
Sema::BuildPossibleImplicitMemberExpr(const CXXScopeSpec &SS,
LookupResult &R,
const TemplateArgumentListInfo *TemplateArgs) {
switch (ClassifyImplicitMemberAccess(*this, CurScope, R)) {
case IMA_Instance:
return BuildImplicitMemberExpr(SS, R, TemplateArgs, true);
case IMA_Mixed:
case IMA_Mixed_Unrelated:
case IMA_Unresolved:
return BuildImplicitMemberExpr(SS, R, TemplateArgs, false);
case IMA_Static:
case IMA_Mixed_StaticContext:
case IMA_Unresolved_StaticContext:
if (TemplateArgs)
return BuildTemplateIdExpr(SS, R, false, *TemplateArgs);
return BuildDeclarationNameExpr(SS, R, false);
case IMA_Error_StaticContext:
case IMA_Error_Unrelated:
DiagnoseInstanceReference(*this, SS, R.getRepresentativeDecl(),
R.getLookupNameInfo());
return ExprError();
}
llvm_unreachable("unexpected instance member access kind");
return ExprError();
}
/// Check an ext-vector component access expression.
///
/// VK should be set in advance to the value kind of the base
/// expression.
static QualType
CheckExtVectorComponent(Sema &S, QualType baseType, ExprValueKind &VK,
SourceLocation OpLoc, const IdentifierInfo *CompName,
SourceLocation CompLoc) {
// FIXME: Share logic with ExtVectorElementExpr::containsDuplicateElements,
// see FIXME there.
//
// FIXME: This logic can be greatly simplified by splitting it along
// halving/not halving and reworking the component checking.
const ExtVectorType *vecType = baseType->getAs<ExtVectorType>();
// The vector accessor can't exceed the number of elements.
const char *compStr = CompName->getNameStart();
// This flag determines whether or not the component is one of the four
// special names that indicate a subset of exactly half the elements are
// to be selected.
bool HalvingSwizzle = false;
// This flag determines whether or not CompName has an 's' char prefix,
// indicating that it is a string of hex values to be used as vector indices.
bool HexSwizzle = *compStr == 's' || *compStr == 'S';
bool HasRepeated = false;
bool HasIndex[16] = {};
int Idx;
// Check that we've found one of the special components, or that the component
// names must come from the same set.
if (!strcmp(compStr, "hi") || !strcmp(compStr, "lo") ||
!strcmp(compStr, "even") || !strcmp(compStr, "odd")) {
HalvingSwizzle = true;
} else if (!HexSwizzle &&
(Idx = vecType->getPointAccessorIdx(*compStr)) != -1) {
do {
if (HasIndex[Idx]) HasRepeated = true;
HasIndex[Idx] = true;
compStr++;
} while (*compStr && (Idx = vecType->getPointAccessorIdx(*compStr)) != -1);
} else {
if (HexSwizzle) compStr++;
while ((Idx = vecType->getNumericAccessorIdx(*compStr)) != -1) {
if (HasIndex[Idx]) HasRepeated = true;
HasIndex[Idx] = true;
compStr++;
}
}
if (!HalvingSwizzle && *compStr) {
// We didn't get to the end of the string. This means the component names
// didn't come from the same set *or* we encountered an illegal name.
S.Diag(OpLoc, diag::err_ext_vector_component_name_illegal)
<< llvm::StringRef(compStr, 1) << SourceRange(CompLoc);
return QualType();
}
// Ensure no component accessor exceeds the width of the vector type it
// operates on.
if (!HalvingSwizzle) {
compStr = CompName->getNameStart();
if (HexSwizzle)
compStr++;
while (*compStr) {
if (!vecType->isAccessorWithinNumElements(*compStr++)) {
S.Diag(OpLoc, diag::err_ext_vector_component_exceeds_length)
<< baseType << SourceRange(CompLoc);
return QualType();
}
}
}
// The component accessor looks fine - now we need to compute the actual type.
// The vector type is implied by the component accessor. For example,
// vec4.b is a float, vec4.xy is a vec2, vec4.rgb is a vec3, etc.
// vec4.s0 is a float, vec4.s23 is a vec3, etc.
// vec4.hi, vec4.lo, vec4.e, and vec4.o all return vec2.
unsigned CompSize = HalvingSwizzle ? (vecType->getNumElements() + 1) / 2
: CompName->getLength();
if (HexSwizzle)
CompSize--;
if (CompSize == 1)
return vecType->getElementType();
if (HasRepeated) VK = VK_RValue;
QualType VT = S.Context.getExtVectorType(vecType->getElementType(), CompSize);
// Now look up the TypeDefDecl from the vector type. Without this,
// diagostics look bad. We want extended vector types to appear built-in.
for (unsigned i = 0, E = S.ExtVectorDecls.size(); i != E; ++i) {
if (S.ExtVectorDecls[i]->getUnderlyingType() == VT)
return S.Context.getTypedefType(S.ExtVectorDecls[i]);
}
return VT; // should never get here (a typedef type should always be found).
}
static Decl *FindGetterSetterNameDeclFromProtocolList(const ObjCProtocolDecl*PDecl,
IdentifierInfo *Member,
const Selector &Sel,
ASTContext &Context) {
if (Member)
if (ObjCPropertyDecl *PD = PDecl->FindPropertyDeclaration(Member))
return PD;
if (ObjCMethodDecl *OMD = PDecl->getInstanceMethod(Sel))
return OMD;
for (ObjCProtocolDecl::protocol_iterator I = PDecl->protocol_begin(),
E = PDecl->protocol_end(); I != E; ++I) {
if (Decl *D = FindGetterSetterNameDeclFromProtocolList(*I, Member, Sel,
Context))
return D;
}
return 0;
}
static Decl *FindGetterSetterNameDecl(const ObjCObjectPointerType *QIdTy,
IdentifierInfo *Member,
const Selector &Sel,
ASTContext &Context) {
// Check protocols on qualified interfaces.
Decl *GDecl = 0;
for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(),
E = QIdTy->qual_end(); I != E; ++I) {
if (Member)
if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) {
GDecl = PD;
break;
}
// Also must look for a getter or setter name which uses property syntax.
if (ObjCMethodDecl *OMD = (*I)->getInstanceMethod(Sel)) {
GDecl = OMD;
break;
}
}
if (!GDecl) {
for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(),
E = QIdTy->qual_end(); I != E; ++I) {
// Search in the protocol-qualifier list of current protocol.
GDecl = FindGetterSetterNameDeclFromProtocolList(*I, Member, Sel,
Context);
if (GDecl)
return GDecl;
}
}
return GDecl;
}
ExprResult
Sema::ActOnDependentMemberExpr(Expr *BaseExpr, QualType BaseType,
bool IsArrow, SourceLocation OpLoc,
const CXXScopeSpec &SS,
NamedDecl *FirstQualifierInScope,
const DeclarationNameInfo &NameInfo,
const TemplateArgumentListInfo *TemplateArgs) {
// Even in dependent contexts, try to diagnose base expressions with
// obviously wrong types, e.g.:
//
// T* t;
// t.f;
//
// In Obj-C++, however, the above expression is valid, since it could be
// accessing the 'f' property if T is an Obj-C interface. The extra check
// allows this, while still reporting an error if T is a struct pointer.
if (!IsArrow) {
const PointerType *PT = BaseType->getAs<PointerType>();
if (PT && (!getLangOptions().ObjC1 ||
PT->getPointeeType()->isRecordType())) {
assert(BaseExpr && "cannot happen with implicit member accesses");
Diag(NameInfo.getLoc(), diag::err_typecheck_member_reference_struct_union)
<< BaseType << BaseExpr->getSourceRange();
return ExprError();
}
}
assert(BaseType->isDependentType() ||
NameInfo.getName().isDependentName() ||
isDependentScopeSpecifier(SS));
// Get the type being accessed in BaseType. If this is an arrow, the BaseExpr
// must have pointer type, and the accessed type is the pointee.
return Owned(CXXDependentScopeMemberExpr::Create(Context, BaseExpr, BaseType,
IsArrow, OpLoc,
SS.getWithLocInContext(Context),
FirstQualifierInScope,
NameInfo, TemplateArgs));
}
/// We know that the given qualified member reference points only to
/// declarations which do not belong to the static type of the base
/// expression. Diagnose the problem.
static void DiagnoseQualifiedMemberReference(Sema &SemaRef,
Expr *BaseExpr,
QualType BaseType,
const CXXScopeSpec &SS,
NamedDecl *rep,
const DeclarationNameInfo &nameInfo) {
// If this is an implicit member access, use a different set of
// diagnostics.
if (!BaseExpr)
return DiagnoseInstanceReference(SemaRef, SS, rep, nameInfo);
SemaRef.Diag(nameInfo.getLoc(), diag::err_qualified_member_of_unrelated)
<< SS.getRange() << rep << BaseType;
}
// Check whether the declarations we found through a nested-name
// specifier in a member expression are actually members of the base
// type. The restriction here is:
//
// C++ [expr.ref]p2:
// ... In these cases, the id-expression shall name a
// member of the class or of one of its base classes.
//
// So it's perfectly legitimate for the nested-name specifier to name
// an unrelated class, and for us to find an overload set including
// decls from classes which are not superclasses, as long as the decl
// we actually pick through overload resolution is from a superclass.
bool Sema::CheckQualifiedMemberReference(Expr *BaseExpr,
QualType BaseType,
const CXXScopeSpec &SS,
const LookupResult &R) {
const RecordType *BaseRT = BaseType->getAs<RecordType>();
if (!BaseRT) {
// We can't check this yet because the base type is still
// dependent.
assert(BaseType->isDependentType());
return false;
}
CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl());
for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
// If this is an implicit member reference and we find a
// non-instance member, it's not an error.
if (!BaseExpr && !(*I)->isCXXInstanceMember())
return false;
// Note that we use the DC of the decl, not the underlying decl.
DeclContext *DC = (*I)->getDeclContext();
while (DC->isTransparentContext())
DC = DC->getParent();
if (!DC->isRecord())
continue;
llvm::SmallPtrSet<CXXRecordDecl*,4> MemberRecord;
MemberRecord.insert(cast<CXXRecordDecl>(DC)->getCanonicalDecl());
if (!IsProvablyNotDerivedFrom(*this, BaseRecord, MemberRecord))
return false;
}
DiagnoseQualifiedMemberReference(*this, BaseExpr, BaseType, SS,
R.getRepresentativeDecl(),
R.getLookupNameInfo());
return true;
}
static bool
LookupMemberExprInRecord(Sema &SemaRef, LookupResult &R,
SourceRange BaseRange, const RecordType *RTy,
SourceLocation OpLoc, CXXScopeSpec &SS,
bool HasTemplateArgs) {
RecordDecl *RDecl = RTy->getDecl();
if (SemaRef.RequireCompleteType(OpLoc, QualType(RTy, 0),
SemaRef.PDiag(diag::err_typecheck_incomplete_tag)
<< BaseRange))
return true;
if (HasTemplateArgs) {
// LookupTemplateName doesn't expect these both to exist simultaneously.
QualType ObjectType = SS.isSet() ? QualType() : QualType(RTy, 0);
bool MOUS;
SemaRef.LookupTemplateName(R, 0, SS, ObjectType, false, MOUS);
return false;
}
DeclContext *DC = RDecl;
if (SS.isSet()) {
// If the member name was a qualified-id, look into the
// nested-name-specifier.
DC = SemaRef.computeDeclContext(SS, false);
if (SemaRef.RequireCompleteDeclContext(SS, DC)) {
SemaRef.Diag(SS.getRange().getEnd(), diag::err_typecheck_incomplete_tag)
<< SS.getRange() << DC;
return true;
}
assert(DC && "Cannot handle non-computable dependent contexts in lookup");
if (!isa<TypeDecl>(DC)) {
SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_nonclass)
<< DC << SS.getRange();
return true;
}
}
// The record definition is complete, now look up the member.
SemaRef.LookupQualifiedName(R, DC);
if (!R.empty())
return false;
// We didn't find anything with the given name, so try to correct
// for typos.
DeclarationName Name = R.getLookupName();
TypoCorrection Corrected = SemaRef.CorrectTypo(R.getLookupNameInfo(),
R.getLookupKind(), NULL,
&SS, DC, false,
Sema::CTC_MemberLookup);
NamedDecl *ND = Corrected.getCorrectionDecl();
R.clear();
if (ND && (isa<ValueDecl>(ND) || isa<FunctionTemplateDecl>(ND))) {
std::string CorrectedStr(
Corrected.getAsString(SemaRef.getLangOptions()));
std::string CorrectedQuotedStr(
Corrected.getQuoted(SemaRef.getLangOptions()));
R.setLookupName(Corrected.getCorrection());
R.addDecl(ND);
SemaRef.Diag(R.getNameLoc(), diag::err_no_member_suggest)
<< Name << DC << CorrectedQuotedStr << SS.getRange()
<< FixItHint::CreateReplacement(R.getNameLoc(), CorrectedStr);
SemaRef.Diag(ND->getLocation(), diag::note_previous_decl)
<< ND->getDeclName();
}
return false;
}
ExprResult
Sema::BuildMemberReferenceExpr(Expr *Base, QualType BaseType,
SourceLocation OpLoc, bool IsArrow,
CXXScopeSpec &SS,
NamedDecl *FirstQualifierInScope,
const DeclarationNameInfo &NameInfo,
const TemplateArgumentListInfo *TemplateArgs) {
if (BaseType->isDependentType() ||
(SS.isSet() && isDependentScopeSpecifier(SS)))
return ActOnDependentMemberExpr(Base, BaseType,
IsArrow, OpLoc,
SS, FirstQualifierInScope,
NameInfo, TemplateArgs);
LookupResult R(*this, NameInfo, LookupMemberName);
// Implicit member accesses.
if (!Base) {
QualType RecordTy = BaseType;
if (IsArrow) RecordTy = RecordTy->getAs<PointerType>()->getPointeeType();
if (LookupMemberExprInRecord(*this, R, SourceRange(),
RecordTy->getAs<RecordType>(),
OpLoc, SS, TemplateArgs != 0))
return ExprError();
// Explicit member accesses.
} else {
ExprResult BaseResult = Owned(Base);
ExprResult Result =
LookupMemberExpr(R, BaseResult, IsArrow, OpLoc,
SS, /*ObjCImpDecl*/ 0, TemplateArgs != 0);
if (BaseResult.isInvalid())
return ExprError();
Base = BaseResult.take();
if (Result.isInvalid()) {
Owned(Base);
return ExprError();
}
if (Result.get())
return move(Result);
// LookupMemberExpr can modify Base, and thus change BaseType
BaseType = Base->getType();
}
return BuildMemberReferenceExpr(Base, BaseType,
OpLoc, IsArrow, SS, FirstQualifierInScope,
R, TemplateArgs);
}
static ExprResult
BuildFieldReferenceExpr(Sema &S, Expr *BaseExpr, bool IsArrow,
const CXXScopeSpec &SS, FieldDecl *Field,
DeclAccessPair FoundDecl,
const DeclarationNameInfo &MemberNameInfo);
ExprResult
Sema::BuildAnonymousStructUnionMemberReference(const CXXScopeSpec &SS,
SourceLocation loc,
IndirectFieldDecl *indirectField,
Expr *baseObjectExpr,
SourceLocation opLoc) {
// First, build the expression that refers to the base object.
bool baseObjectIsPointer = false;
Qualifiers baseQuals;
// Case 1: the base of the indirect field is not a field.
VarDecl *baseVariable = indirectField->getVarDecl();
CXXScopeSpec EmptySS;
if (baseVariable) {
assert(baseVariable->getType()->isRecordType());
// In principle we could have a member access expression that
// accesses an anonymous struct/union that's a static member of
// the base object's class. However, under the current standard,
// static data members cannot be anonymous structs or unions.
// Supporting this is as easy as building a MemberExpr here.
assert(!baseObjectExpr && "anonymous struct/union is static data member?");
DeclarationNameInfo baseNameInfo(DeclarationName(), loc);
ExprResult result
= BuildDeclarationNameExpr(EmptySS, baseNameInfo, baseVariable);
if (result.isInvalid()) return ExprError();
baseObjectExpr = result.take();
baseObjectIsPointer = false;
baseQuals = baseObjectExpr->getType().getQualifiers();
// Case 2: the base of the indirect field is a field and the user
// wrote a member expression.
} else if (baseObjectExpr) {
// The caller provided the base object expression. Determine
// whether its a pointer and whether it adds any qualifiers to the
// anonymous struct/union fields we're looking into.
QualType objectType = baseObjectExpr->getType();
if (const PointerType *ptr = objectType->getAs<PointerType>()) {
baseObjectIsPointer = true;
objectType = ptr->getPointeeType();
} else {
baseObjectIsPointer = false;
}
baseQuals = objectType.getQualifiers();
// Case 3: the base of the indirect field is a field and we should
// build an implicit member access.
} else {
// We've found a member of an anonymous struct/union that is
// inside a non-anonymous struct/union, so in a well-formed
// program our base object expression is "this".
QualType ThisTy = getAndCaptureCurrentThisType();
if (ThisTy.isNull()) {
Diag(loc, diag::err_invalid_member_use_in_static_method)
<< indirectField->getDeclName();
return ExprError();
}
// Our base object expression is "this".
baseObjectExpr
= new (Context) CXXThisExpr(loc, ThisTy, /*isImplicit=*/ true);
baseObjectIsPointer = true;
baseQuals = ThisTy->castAs<PointerType>()->getPointeeType().getQualifiers();
}
// Build the implicit member references to the field of the
// anonymous struct/union.
Expr *result = baseObjectExpr;
IndirectFieldDecl::chain_iterator
FI = indirectField->chain_begin(), FEnd = indirectField->chain_end();
// Build the first member access in the chain with full information.
if (!baseVariable) {
FieldDecl *field = cast<FieldDecl>(*FI);
// FIXME: use the real found-decl info!
DeclAccessPair foundDecl = DeclAccessPair::make(field, field->getAccess());
// Make a nameInfo that properly uses the anonymous name.
DeclarationNameInfo memberNameInfo(field->getDeclName(), loc);
result = BuildFieldReferenceExpr(*this, result, baseObjectIsPointer,
EmptySS, field, foundDecl,
memberNameInfo).take();
baseObjectIsPointer = false;
// FIXME: check qualified member access
}
// In all cases, we should now skip the first declaration in the chain.
++FI;
while (FI != FEnd) {
FieldDecl *field = cast<FieldDecl>(*FI++);
// FIXME: these are somewhat meaningless
DeclarationNameInfo memberNameInfo(field->getDeclName(), loc);
DeclAccessPair foundDecl = DeclAccessPair::make(field, field->getAccess());
result = BuildFieldReferenceExpr(*this, result, /*isarrow*/ false,
(FI == FEnd? SS : EmptySS), field,
foundDecl, memberNameInfo).take();
}
return Owned(result);
}
/// \brief Build a MemberExpr AST node.
static MemberExpr *BuildMemberExpr(ASTContext &C, Expr *Base, bool isArrow,
const CXXScopeSpec &SS, ValueDecl *Member,
DeclAccessPair FoundDecl,
const DeclarationNameInfo &MemberNameInfo,
QualType Ty,
ExprValueKind VK, ExprObjectKind OK,
const TemplateArgumentListInfo *TemplateArgs = 0) {
return MemberExpr::Create(C, Base, isArrow, SS.getWithLocInContext(C),
Member, FoundDecl, MemberNameInfo,
TemplateArgs, Ty, VK, OK);
}
ExprResult
Sema::BuildMemberReferenceExpr(Expr *BaseExpr, QualType BaseExprType,
SourceLocation OpLoc, bool IsArrow,
const CXXScopeSpec &SS,
NamedDecl *FirstQualifierInScope,
LookupResult &R,
const TemplateArgumentListInfo *TemplateArgs,
bool SuppressQualifierCheck) {
QualType BaseType = BaseExprType;
if (IsArrow) {
assert(BaseType->isPointerType());
BaseType = BaseType->getAs<PointerType>()->getPointeeType();
}
R.setBaseObjectType(BaseType);
const DeclarationNameInfo &MemberNameInfo = R.getLookupNameInfo();
DeclarationName MemberName = MemberNameInfo.getName();
SourceLocation MemberLoc = MemberNameInfo.getLoc();
if (R.isAmbiguous())
return ExprError();
if (R.empty()) {
// Rederive where we looked up.
DeclContext *DC = (SS.isSet()
? computeDeclContext(SS, false)
: BaseType->getAs<RecordType>()->getDecl());
Diag(R.getNameLoc(), diag::err_no_member)
<< MemberName << DC
<< (BaseExpr ? BaseExpr->getSourceRange() : SourceRange());
return ExprError();
}
// Diagnose lookups that find only declarations from a non-base
// type. This is possible for either qualified lookups (which may
// have been qualified with an unrelated type) or implicit member
// expressions (which were found with unqualified lookup and thus
// may have come from an enclosing scope). Note that it's okay for
// lookup to find declarations from a non-base type as long as those
// aren't the ones picked by overload resolution.
if ((SS.isSet() || !BaseExpr ||
(isa<CXXThisExpr>(BaseExpr) &&
cast<CXXThisExpr>(BaseExpr)->isImplicit())) &&
!SuppressQualifierCheck &&
CheckQualifiedMemberReference(BaseExpr, BaseType, SS, R))
return ExprError();
// Construct an unresolved result if we in fact got an unresolved
// result.
if (R.isOverloadedResult() || R.isUnresolvableResult()) {
// Suppress any lookup-related diagnostics; we'll do these when we
// pick a member.
R.suppressDiagnostics();
UnresolvedMemberExpr *MemExpr
= UnresolvedMemberExpr::Create(Context, R.isUnresolvableResult(),
BaseExpr, BaseExprType,
IsArrow, OpLoc,
SS.getWithLocInContext(Context),
MemberNameInfo,
TemplateArgs, R.begin(), R.end());
return Owned(MemExpr);
}
assert(R.isSingleResult());
DeclAccessPair FoundDecl = R.begin().getPair();
NamedDecl *MemberDecl = R.getFoundDecl();
// FIXME: diagnose the presence of template arguments now.
// If the decl being referenced had an error, return an error for this
// sub-expr without emitting another error, in order to avoid cascading
// error cases.
if (MemberDecl->isInvalidDecl())
return ExprError();
// Handle the implicit-member-access case.
if (!BaseExpr) {
// If this is not an instance member, convert to a non-member access.
if (!MemberDecl->isCXXInstanceMember())
return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), MemberDecl);
SourceLocation Loc = R.getNameLoc();
if (SS.getRange().isValid())
Loc = SS.getRange().getBegin();
BaseExpr = new (Context) CXXThisExpr(Loc, BaseExprType,/*isImplicit=*/true);
}
bool ShouldCheckUse = true;
if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MemberDecl)) {
// Don't diagnose the use of a virtual member function unless it's
// explicitly qualified.
if (MD->isVirtual() && !SS.isSet())
ShouldCheckUse = false;
}
// Check the use of this member.
if (ShouldCheckUse && DiagnoseUseOfDecl(MemberDecl, MemberLoc)) {
Owned(BaseExpr);
return ExprError();
}
// Perform a property load on the base regardless of whether we
// actually need it for the declaration.
if (BaseExpr->getObjectKind() == OK_ObjCProperty) {
ExprResult Result = ConvertPropertyForRValue(BaseExpr);
if (Result.isInvalid())
return ExprError();
BaseExpr = Result.take();
}
if (FieldDecl *FD = dyn_cast<FieldDecl>(MemberDecl))
return BuildFieldReferenceExpr(*this, BaseExpr, IsArrow,
SS, FD, FoundDecl, MemberNameInfo);
if (IndirectFieldDecl *FD = dyn_cast<IndirectFieldDecl>(MemberDecl))
// We may have found a field within an anonymous union or struct
// (C++ [class.union]).
return BuildAnonymousStructUnionMemberReference(SS, MemberLoc, FD,
BaseExpr, OpLoc);
if (VarDecl *Var = dyn_cast<VarDecl>(MemberDecl)) {
MarkDeclarationReferenced(MemberLoc, Var);
return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS,
Var, FoundDecl, MemberNameInfo,
Var->getType().getNonReferenceType(),
VK_LValue, OK_Ordinary));
}
if (CXXMethodDecl *MemberFn = dyn_cast<CXXMethodDecl>(MemberDecl)) {
ExprValueKind valueKind;
QualType type;
if (MemberFn->isInstance()) {
valueKind = VK_RValue;
type = Context.BoundMemberTy;
} else {
valueKind = VK_LValue;
type = MemberFn->getType();
}
MarkDeclarationReferenced(MemberLoc, MemberDecl);
return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS,
MemberFn, FoundDecl, MemberNameInfo,
type, valueKind, OK_Ordinary));
}
assert(!isa<FunctionDecl>(MemberDecl) && "member function not C++ method?");
if (EnumConstantDecl *Enum = dyn_cast<EnumConstantDecl>(MemberDecl)) {
MarkDeclarationReferenced(MemberLoc, MemberDecl);
return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS,
Enum, FoundDecl, MemberNameInfo,
Enum->getType(), VK_RValue, OK_Ordinary));
}
Owned(BaseExpr);
// We found something that we didn't expect. Complain.
if (isa<TypeDecl>(MemberDecl))
Diag(MemberLoc, diag::err_typecheck_member_reference_type)
<< MemberName << BaseType << int(IsArrow);
else
Diag(MemberLoc, diag::err_typecheck_member_reference_unknown)
<< MemberName << BaseType << int(IsArrow);
Diag(MemberDecl->getLocation(), diag::note_member_declared_here)
<< MemberName;
R.suppressDiagnostics();
return ExprError();
}
/// Given that normal member access failed on the given expression,
/// and given that the expression's type involves builtin-id or
/// builtin-Class, decide whether substituting in the redefinition
/// types would be profitable. The redefinition type is whatever
/// this translation unit tried to typedef to id/Class; we store
/// it to the side and then re-use it in places like this.
static bool ShouldTryAgainWithRedefinitionType(Sema &S, ExprResult &base) {
const ObjCObjectPointerType *opty
= base.get()->getType()->getAs<ObjCObjectPointerType>();
if (!opty) return false;
const ObjCObjectType *ty = opty->getObjectType();
QualType redef;
if (ty->isObjCId()) {
redef = S.Context.ObjCIdRedefinitionType;
} else if (ty->isObjCClass()) {
redef = S.Context.ObjCClassRedefinitionType;
} else {
return false;
}
// Do the substitution as long as the redefinition type isn't just a
// possibly-qualified pointer to builtin-id or builtin-Class again.
opty = redef->getAs<ObjCObjectPointerType>();
if (opty && !opty->getObjectType()->getInterface() != 0)
return false;
base = S.ImpCastExprToType(base.take(), redef, CK_BitCast);
return true;
}
/// Look up the given member of the given non-type-dependent
/// expression. This can return in one of two ways:
/// * If it returns a sentinel null-but-valid result, the caller will
/// assume that lookup was performed and the results written into
/// the provided structure. It will take over from there.
/// * Otherwise, the returned expression will be produced in place of
/// an ordinary member expression.
///
/// The ObjCImpDecl bit is a gross hack that will need to be properly
/// fixed for ObjC++.
ExprResult
Sema::LookupMemberExpr(LookupResult &R, ExprResult &BaseExpr,
bool &IsArrow, SourceLocation OpLoc,
CXXScopeSpec &SS,
Decl *ObjCImpDecl, bool HasTemplateArgs) {
assert(BaseExpr.get() && "no base expression");
// Perform default conversions.
BaseExpr = DefaultFunctionArrayConversion(BaseExpr.take());
if (IsArrow) {
BaseExpr = DefaultLvalueConversion(BaseExpr.take());
if (BaseExpr.isInvalid())
return ExprError();
}
QualType BaseType = BaseExpr.get()->getType();
assert(!BaseType->isDependentType());
DeclarationName MemberName = R.getLookupName();
SourceLocation MemberLoc = R.getNameLoc();
// For later type-checking purposes, turn arrow accesses into dot
// accesses. The only access type we support that doesn't follow
// the C equivalence "a->b === (*a).b" is ObjC property accesses,
// and those never use arrows, so this is unaffected.
if (IsArrow) {
if (const PointerType *Ptr = BaseType->getAs<PointerType>())
BaseType = Ptr->getPointeeType();
else if (const ObjCObjectPointerType *Ptr
= BaseType->getAs<ObjCObjectPointerType>())
BaseType = Ptr->getPointeeType();
else if (BaseType->isRecordType()) {
// Recover from arrow accesses to records, e.g.:
// struct MyRecord foo;
// foo->bar
// This is actually well-formed in C++ if MyRecord has an
// overloaded operator->, but that should have been dealt with
// by now.
Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
<< BaseType << int(IsArrow) << BaseExpr.get()->getSourceRange()
<< FixItHint::CreateReplacement(OpLoc, ".");
IsArrow = false;
} else if (BaseType == Context.BoundMemberTy) {
goto fail;
} else {
Diag(MemberLoc, diag::err_typecheck_member_reference_arrow)
<< BaseType << BaseExpr.get()->getSourceRange();
return ExprError();
}
}
// Handle field access to simple records.
if (const RecordType *RTy = BaseType->getAs<RecordType>()) {
if (LookupMemberExprInRecord(*this, R, BaseExpr.get()->getSourceRange(),
RTy, OpLoc, SS, HasTemplateArgs))
return ExprError();
// Returning valid-but-null is how we indicate to the caller that
// the lookup result was filled in.
return Owned((Expr*) 0);
}
// Handle ivar access to Objective-C objects.
if (const ObjCObjectType *OTy = BaseType->getAs<ObjCObjectType>()) {
IdentifierInfo *Member = MemberName.getAsIdentifierInfo();
// There are three cases for the base type:
// - builtin id (qualified or unqualified)
// - builtin Class (qualified or unqualified)
// - an interface
ObjCInterfaceDecl *IDecl = OTy->getInterface();
if (!IDecl) {
if (getLangOptions().ObjCAutoRefCount &&
(OTy->isObjCId() || OTy->isObjCClass()))
goto fail;
// There's an implicit 'isa' ivar on all objects.
// But we only actually find it this way on objects of type 'id',
// apparently.
if (OTy->isObjCId() && Member->isStr("isa"))
return Owned(new (Context) ObjCIsaExpr(BaseExpr.take(), IsArrow, MemberLoc,
Context.getObjCClassType()));
if (ShouldTryAgainWithRedefinitionType(*this, BaseExpr))
return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS,
ObjCImpDecl, HasTemplateArgs);
goto fail;
}
ObjCInterfaceDecl *ClassDeclared;
ObjCIvarDecl *IV = IDecl->lookupInstanceVariable(Member, ClassDeclared);
if (!IV) {
// Attempt to correct for typos in ivar names.
LookupResult Res(*this, R.getLookupName(), R.getNameLoc(),
LookupMemberName);
TypoCorrection Corrected = CorrectTypo(
R.getLookupNameInfo(), LookupMemberName, NULL, NULL, IDecl, false,
IsArrow ? CTC_ObjCIvarLookup : CTC_ObjCPropertyLookup);
if ((IV = Corrected.getCorrectionDeclAs<ObjCIvarDecl>())) {
Diag(R.getNameLoc(),
diag::err_typecheck_member_reference_ivar_suggest)
<< IDecl->getDeclName() << MemberName << IV->getDeclName()
<< FixItHint::CreateReplacement(R.getNameLoc(),
IV->getNameAsString());
Diag(IV->getLocation(), diag::note_previous_decl)
<< IV->getDeclName();
} else {
if (IsArrow && IDecl->FindPropertyDeclaration(Member)) {
Diag(MemberLoc,
diag::err_property_found_suggest)
<< Member << BaseExpr.get()->getType()
<< FixItHint::CreateReplacement(OpLoc, ".");
return ExprError();
}
Res.clear();
Res.setLookupName(Member);
Diag(MemberLoc, diag::err_typecheck_member_reference_ivar)
<< IDecl->getDeclName() << MemberName
<< BaseExpr.get()->getSourceRange();
return ExprError();
}
}
// If the decl being referenced had an error, return an error for this
// sub-expr without emitting another error, in order to avoid cascading
// error cases.
if (IV->isInvalidDecl())
return ExprError();
// Check whether we can reference this field.
if (DiagnoseUseOfDecl(IV, MemberLoc))
return ExprError();
if (IV->getAccessControl() != ObjCIvarDecl::Public &&
IV->getAccessControl() != ObjCIvarDecl::Package) {
ObjCInterfaceDecl *ClassOfMethodDecl = 0;
if (ObjCMethodDecl *MD = getCurMethodDecl())
ClassOfMethodDecl = MD->getClassInterface();
else if (ObjCImpDecl && getCurFunctionDecl()) {
// Case of a c-function declared inside an objc implementation.
// FIXME: For a c-style function nested inside an objc implementation
// class, there is no implementation context available, so we pass
// down the context as argument to this routine. Ideally, this context
// need be passed down in the AST node and somehow calculated from the
// AST for a function decl.
if (ObjCImplementationDecl *IMPD =
dyn_cast<ObjCImplementationDecl>(ObjCImpDecl))
ClassOfMethodDecl = IMPD->getClassInterface();
else if (ObjCCategoryImplDecl* CatImplClass =
dyn_cast<ObjCCategoryImplDecl>(ObjCImpDecl))
ClassOfMethodDecl = CatImplClass->getClassInterface();
}
if (IV->getAccessControl() == ObjCIvarDecl::Private) {
if (ClassDeclared != IDecl ||
ClassOfMethodDecl != ClassDeclared)
Diag(MemberLoc, diag::error_private_ivar_access)
<< IV->getDeclName();
} else if (!IDecl->isSuperClassOf(ClassOfMethodDecl))
// @protected
Diag(MemberLoc, diag::error_protected_ivar_access)
<< IV->getDeclName();
}
if (getLangOptions().ObjCAutoRefCount) {
Expr *BaseExp = BaseExpr.get()->IgnoreParenImpCasts();
if (UnaryOperator *UO = dyn_cast<UnaryOperator>(BaseExp))
if (UO->getOpcode() == UO_Deref)
BaseExp = UO->getSubExpr()->IgnoreParenCasts();
if (DeclRefExpr *DE = dyn_cast<DeclRefExpr>(BaseExp))
if (DE->getType().getObjCLifetime() == Qualifiers::OCL_Weak)
Diag(DE->getLocation(), diag::error_arc_weak_ivar_access);
}
return Owned(new (Context) ObjCIvarRefExpr(IV, IV->getType(),
MemberLoc, BaseExpr.take(),
IsArrow));
}
// Objective-C property access.
const ObjCObjectPointerType *OPT;
if (!IsArrow && (OPT = BaseType->getAs<ObjCObjectPointerType>())) {
// This actually uses the base as an r-value.
BaseExpr = DefaultLvalueConversion(BaseExpr.take());
if (BaseExpr.isInvalid())
return ExprError();
assert(Context.hasSameUnqualifiedType(BaseType, BaseExpr.get()->getType()));
IdentifierInfo *Member = MemberName.getAsIdentifierInfo();
const ObjCObjectType *OT = OPT->getObjectType();
// id, with and without qualifiers.
if (OT->isObjCId()) {
// Check protocols on qualified interfaces.
Selector Sel = PP.getSelectorTable().getNullarySelector(Member);
if (Decl *PMDecl = FindGetterSetterNameDecl(OPT, Member, Sel, Context)) {
if (ObjCPropertyDecl *PD = dyn_cast<ObjCPropertyDecl>(PMDecl)) {
// Check the use of this declaration
if (DiagnoseUseOfDecl(PD, MemberLoc))
return ExprError();
QualType T = PD->getType();
if (ObjCMethodDecl *Getter = PD->getGetterMethodDecl())
T = getMessageSendResultType(BaseType, Getter, false, false);
return Owned(new (Context) ObjCPropertyRefExpr(PD, T,
VK_LValue,
OK_ObjCProperty,
MemberLoc,
BaseExpr.take()));
}
if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(PMDecl)) {
// Check the use of this method.
if (DiagnoseUseOfDecl(OMD, MemberLoc))
return ExprError();
Selector SetterSel =
SelectorTable::constructSetterName(PP.getIdentifierTable(),
PP.getSelectorTable(), Member);
ObjCMethodDecl *SMD = 0;
if (Decl *SDecl = FindGetterSetterNameDecl(OPT, /*Property id*/0,
SetterSel, Context))
SMD = dyn_cast<ObjCMethodDecl>(SDecl);
QualType PType = getMessageSendResultType(BaseType, OMD, false,
false);
ExprValueKind VK = VK_LValue;
if (!getLangOptions().CPlusPlus && PType.isCForbiddenLValueType())
VK = VK_RValue;
ExprObjectKind OK = (VK == VK_RValue ? OK_Ordinary : OK_ObjCProperty);
return Owned(new (Context) ObjCPropertyRefExpr(OMD, SMD, PType,
VK, OK,
MemberLoc, BaseExpr.take()));
}
}
// Use of id.member can only be for a property reference. Do not
// use the 'id' redefinition in this case.
if (IsArrow && ShouldTryAgainWithRedefinitionType(*this, BaseExpr))
return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS,
ObjCImpDecl, HasTemplateArgs);
return ExprError(Diag(MemberLoc, diag::err_property_not_found)
<< MemberName << BaseType);
}
// 'Class', unqualified only.
if (OT->isObjCClass()) {
// Only works in a method declaration (??!).
ObjCMethodDecl *MD = getCurMethodDecl();
if (!MD) {
if (ShouldTryAgainWithRedefinitionType(*this, BaseExpr))
return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS,
ObjCImpDecl, HasTemplateArgs);
goto fail;
}
// Also must look for a getter name which uses property syntax.
Selector Sel = PP.getSelectorTable().getNullarySelector(Member);
ObjCInterfaceDecl *IFace = MD->getClassInterface();
ObjCMethodDecl *Getter;
if ((Getter = IFace->lookupClassMethod(Sel))) {
// Check the use of this method.
if (DiagnoseUseOfDecl(Getter, MemberLoc))
return ExprError();
} else
Getter = IFace->lookupPrivateMethod(Sel, false);
// If we found a getter then this may be a valid dot-reference, we
// will look for the matching setter, in case it is needed.
Selector SetterSel =
SelectorTable::constructSetterName(PP.getIdentifierTable(),
PP.getSelectorTable(), Member);
ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel);
if (!Setter) {
// If this reference is in an @implementation, also check for 'private'
// methods.
Setter = IFace->lookupPrivateMethod(SetterSel, false);
}
// Look through local category implementations associated with the class.
if (!Setter)
Setter = IFace->getCategoryClassMethod(SetterSel);
if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc))
return ExprError();
if (Getter || Setter) {
QualType PType;
ExprValueKind VK = VK_LValue;
if (Getter) {
PType = getMessageSendResultType(QualType(OT, 0), Getter, true,
false);
if (!getLangOptions().CPlusPlus && PType.isCForbiddenLValueType())
VK = VK_RValue;
} else {
// Get the expression type from Setter's incoming parameter.
PType = (*(Setter->param_end() -1))->getType();
}
ExprObjectKind OK = (VK == VK_RValue ? OK_Ordinary : OK_ObjCProperty);
// FIXME: we must check that the setter has property type.
return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
PType, VK, OK,
MemberLoc, BaseExpr.take()));
}
if (ShouldTryAgainWithRedefinitionType(*this, BaseExpr))
return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS,
ObjCImpDecl, HasTemplateArgs);
return ExprError(Diag(MemberLoc, diag::err_property_not_found)
<< MemberName << BaseType);
}
// Normal property access.
return HandleExprPropertyRefExpr(OPT, BaseExpr.get(), OpLoc,
MemberName, MemberLoc,
SourceLocation(), QualType(), false);
}
// Handle 'field access' to vectors, such as 'V.xx'.
if (BaseType->isExtVectorType()) {
// FIXME: this expr should store IsArrow.
IdentifierInfo *Member = MemberName.getAsIdentifierInfo();
ExprValueKind VK = (IsArrow ? VK_LValue : BaseExpr.get()->getValueKind());
QualType ret = CheckExtVectorComponent(*this, BaseType, VK, OpLoc,
Member, MemberLoc);
if (ret.isNull())
return ExprError();
return Owned(new (Context) ExtVectorElementExpr(ret, VK, BaseExpr.take(),
*Member, MemberLoc));
}
// Adjust builtin-sel to the appropriate redefinition type if that's
// not just a pointer to builtin-sel again.
if (IsArrow &&
BaseType->isSpecificBuiltinType(BuiltinType::ObjCSel) &&
!Context.ObjCSelRedefinitionType->isObjCSelType()) {
BaseExpr = ImpCastExprToType(BaseExpr.take(), Context.ObjCSelRedefinitionType,
CK_BitCast);
return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS,
ObjCImpDecl, HasTemplateArgs);
}
// Failure cases.
fail:
// Recover from dot accesses to pointers, e.g.:
// type *foo;
// foo.bar
// This is actually well-formed in two cases:
// - 'type' is an Objective C type
// - 'bar' is a pseudo-destructor name which happens to refer to
// the appropriate pointer type
if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
if (!IsArrow && Ptr->getPointeeType()->isRecordType() &&
MemberName.getNameKind() != DeclarationName::CXXDestructorName) {
Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
<< BaseType << int(IsArrow) << BaseExpr.get()->getSourceRange()
<< FixItHint::CreateReplacement(OpLoc, "->");
// Recurse as an -> access.
IsArrow = true;
return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS,
ObjCImpDecl, HasTemplateArgs);
}
}
// If the user is trying to apply -> or . to a function name, it's probably
// because they forgot parentheses to call that function.
QualType ZeroArgCallTy;
UnresolvedSet<4> Overloads;
if (isExprCallable(*BaseExpr.get(), ZeroArgCallTy, Overloads)) {
if (ZeroArgCallTy.isNull()) {
Diag(BaseExpr.get()->getExprLoc(), diag::err_member_reference_needs_call)
<< (Overloads.size() > 1) << 0 << BaseExpr.get()->getSourceRange();
UnresolvedSet<2> PlausibleOverloads;
for (OverloadExpr::decls_iterator It = Overloads.begin(),
DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
const FunctionDecl *OverloadDecl = cast<FunctionDecl>(*It);
QualType OverloadResultTy = OverloadDecl->getResultType();
if ((!IsArrow && OverloadResultTy->isRecordType()) ||
(IsArrow && OverloadResultTy->isPointerType() &&
OverloadResultTy->getPointeeType()->isRecordType()))
PlausibleOverloads.addDecl(It.getDecl());
}
NoteOverloads(PlausibleOverloads, BaseExpr.get()->getExprLoc());
return ExprError();
}
if ((!IsArrow && ZeroArgCallTy->isRecordType()) ||
(IsArrow && ZeroArgCallTy->isPointerType() &&
ZeroArgCallTy->getPointeeType()->isRecordType())) {
// At this point, we know BaseExpr looks like it's potentially callable
// with 0 arguments, and that it returns something of a reasonable type,
// so we can emit a fixit and carry on pretending that BaseExpr was
// actually a CallExpr.
SourceLocation ParenInsertionLoc =
PP.getLocForEndOfToken(BaseExpr.get()->getLocEnd());
Diag(BaseExpr.get()->getExprLoc(), diag::err_member_reference_needs_call)
<< (Overloads.size() > 1) << 1 << BaseExpr.get()->getSourceRange()
<< FixItHint::CreateInsertion(ParenInsertionLoc, "()");
// FIXME: Try this before emitting the fixit, and suppress diagnostics
// while doing so.
ExprResult NewBase =
ActOnCallExpr(0, BaseExpr.take(), ParenInsertionLoc,
MultiExprArg(*this, 0, 0),
ParenInsertionLoc.getFileLocWithOffset(1));
if (NewBase.isInvalid())
return ExprError();
BaseExpr = NewBase;
BaseExpr = DefaultFunctionArrayConversion(BaseExpr.take());
return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS,
ObjCImpDecl, HasTemplateArgs);
}
}
Diag(MemberLoc, diag::err_typecheck_member_reference_struct_union)
<< BaseType << BaseExpr.get()->getSourceRange();
return ExprError();
}
/// The main callback when the parser finds something like
/// expression . [nested-name-specifier] identifier
/// expression -> [nested-name-specifier] identifier
/// where 'identifier' encompasses a fairly broad spectrum of
/// possibilities, including destructor and operator references.
///
/// \param OpKind either tok::arrow or tok::period
/// \param HasTrailingLParen whether the next token is '(', which
/// is used to diagnose mis-uses of special members that can
/// only be called
/// \param ObjCImpDecl the current ObjC @implementation decl;
/// this is an ugly hack around the fact that ObjC @implementations
/// aren't properly put in the context chain
ExprResult Sema::ActOnMemberAccessExpr(Scope *S, Expr *Base,
SourceLocation OpLoc,
tok::TokenKind OpKind,
CXXScopeSpec &SS,
UnqualifiedId &Id,
Decl *ObjCImpDecl,
bool HasTrailingLParen) {
if (SS.isSet() && SS.isInvalid())
return ExprError();
// Warn about the explicit constructor calls Microsoft extension.
if (getLangOptions().Microsoft &&
Id.getKind() == UnqualifiedId::IK_ConstructorName)
Diag(Id.getSourceRange().getBegin(),
diag::ext_ms_explicit_constructor_call);
TemplateArgumentListInfo TemplateArgsBuffer;
// Decompose the name into its component parts.
DeclarationNameInfo NameInfo;
const TemplateArgumentListInfo *TemplateArgs;
DecomposeUnqualifiedId(Id, TemplateArgsBuffer,
NameInfo, TemplateArgs);
DeclarationName Name = NameInfo.getName();
bool IsArrow = (OpKind == tok::arrow);
NamedDecl *FirstQualifierInScope
= (!SS.isSet() ? 0 : FindFirstQualifierInScope(S,
static_cast<NestedNameSpecifier*>(SS.getScopeRep())));
// This is a postfix expression, so get rid of ParenListExprs.
ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base);
if (Result.isInvalid()) return ExprError();
Base = Result.take();
if (Base->getType()->isDependentType() || Name.isDependentName() ||
isDependentScopeSpecifier(SS)) {
Result = ActOnDependentMemberExpr(Base, Base->getType(),
IsArrow, OpLoc,
SS, FirstQualifierInScope,
NameInfo, TemplateArgs);
} else {
LookupResult R(*this, NameInfo, LookupMemberName);
ExprResult BaseResult = Owned(Base);
Result = LookupMemberExpr(R, BaseResult, IsArrow, OpLoc,
SS, ObjCImpDecl, TemplateArgs != 0);
if (BaseResult.isInvalid())
return ExprError();
Base = BaseResult.take();
if (Result.isInvalid()) {
Owned(Base);
return ExprError();
}
if (Result.get()) {
// The only way a reference to a destructor can be used is to
// immediately call it, which falls into this case. If the
// next token is not a '(', produce a diagnostic and build the
// call now.
if (!HasTrailingLParen &&
Id.getKind() == UnqualifiedId::IK_DestructorName)
return DiagnoseDtorReference(NameInfo.getLoc(), Result.get());
return move(Result);
}
Result = BuildMemberReferenceExpr(Base, Base->getType(),
OpLoc, IsArrow, SS, FirstQualifierInScope,
R, TemplateArgs);
}
return move(Result);
}
static ExprResult
BuildFieldReferenceExpr(Sema &S, Expr *BaseExpr, bool IsArrow,
const CXXScopeSpec &SS, FieldDecl *Field,
DeclAccessPair FoundDecl,
const DeclarationNameInfo &MemberNameInfo) {
// x.a is an l-value if 'a' has a reference type. Otherwise:
// x.a is an l-value/x-value/pr-value if the base is (and note
// that *x is always an l-value), except that if the base isn't
// an ordinary object then we must have an rvalue.
ExprValueKind VK = VK_LValue;
ExprObjectKind OK = OK_Ordinary;
if (!IsArrow) {
if (BaseExpr->getObjectKind() == OK_Ordinary)
VK = BaseExpr->getValueKind();
else
VK = VK_RValue;
}
if (VK != VK_RValue && Field->isBitField())
OK = OK_BitField;
// Figure out the type of the member; see C99 6.5.2.3p3, C++ [expr.ref]
QualType MemberType = Field->getType();
if (const ReferenceType *Ref = MemberType->getAs<ReferenceType>()) {
MemberType = Ref->getPointeeType();
VK = VK_LValue;
} else {
QualType BaseType = BaseExpr->getType();
if (IsArrow) BaseType = BaseType->getAs<PointerType>()->getPointeeType();
Qualifiers BaseQuals = BaseType.getQualifiers();
// GC attributes are never picked up by members.
BaseQuals.removeObjCGCAttr();
// CVR attributes from the base are picked up by members,
// except that 'mutable' members don't pick up 'const'.
if (Field->isMutable()) BaseQuals.removeConst();
Qualifiers MemberQuals
= S.Context.getCanonicalType(MemberType).getQualifiers();
// TR 18037 does not allow fields to be declared with address spaces.
assert(!MemberQuals.hasAddressSpace());
Qualifiers Combined = BaseQuals + MemberQuals;
if (Combined != MemberQuals)
MemberType = S.Context.getQualifiedType(MemberType, Combined);
}
S.MarkDeclarationReferenced(MemberNameInfo.getLoc(), Field);
ExprResult Base =
S.PerformObjectMemberConversion(BaseExpr, SS.getScopeRep(),
FoundDecl, Field);
if (Base.isInvalid())
return ExprError();
return S.Owned(BuildMemberExpr(S.Context, Base.take(), IsArrow, SS,
Field, FoundDecl, MemberNameInfo,
MemberType, VK, OK));
}
/// Builds an implicit member access expression. The current context
/// is known to be an instance method, and the given unqualified lookup
/// set is known to contain only instance members, at least one of which
/// is from an appropriate type.
ExprResult
Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS,
LookupResult &R,
const TemplateArgumentListInfo *TemplateArgs,
bool IsKnownInstance) {
assert(!R.empty() && !R.isAmbiguous());
SourceLocation loc = R.getNameLoc();
// We may have found a field within an anonymous union or struct
// (C++ [class.union]).
// FIXME: template-ids inside anonymous structs?
if (IndirectFieldDecl *FD = R.getAsSingle<IndirectFieldDecl>())
return BuildAnonymousStructUnionMemberReference(SS, R.getNameLoc(), FD);
// If this is known to be an instance access, go ahead and build an
// implicit 'this' expression now.
// 'this' expression now.
QualType ThisTy = getAndCaptureCurrentThisType();
assert(!ThisTy.isNull() && "didn't correctly pre-flight capture of 'this'");
Expr *baseExpr = 0; // null signifies implicit access
if (IsKnownInstance) {
SourceLocation Loc = R.getNameLoc();
if (SS.getRange().isValid())
Loc = SS.getRange().getBegin();
baseExpr = new (Context) CXXThisExpr(loc, ThisTy, /*isImplicit=*/true);
}
return BuildMemberReferenceExpr(baseExpr, ThisTy,
/*OpLoc*/ SourceLocation(),
/*IsArrow*/ true,
SS,
/*FirstQualifierInScope*/ 0,
R, TemplateArgs);
}
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