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//===--------------------- SemaLookup.cpp - Name Lookup ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements name lookup for C, C++, Objective-C, and
// Objective-C++.
//
//===----------------------------------------------------------------------===//
#include "clang/Sema/Sema.h"
#include "clang/Sema/SemaInternal.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/Overload.h"
#include "clang/Sema/DeclSpec.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/ScopeInfo.h"
#include "clang/Sema/TemplateDeduction.h"
#include "clang/Sema/ExternalSemaSource.h"
#include "clang/Sema/TypoCorrection.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclLookups.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/Basic/Builtins.h"
#include "clang/Basic/LangOptions.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/TinyPtrVector.h"
#include "llvm/ADT/edit_distance.h"
#include "llvm/Support/ErrorHandling.h"
#include <algorithm>
#include <iterator>
#include <limits>
#include <list>
#include <map>
#include <set>
#include <utility>
#include <vector>
using namespace clang;
using namespace sema;
namespace {
class UnqualUsingEntry {
const DeclContext *Nominated;
const DeclContext *CommonAncestor;
public:
UnqualUsingEntry(const DeclContext *Nominated,
const DeclContext *CommonAncestor)
: Nominated(Nominated), CommonAncestor(CommonAncestor) {
}
const DeclContext *getCommonAncestor() const {
return CommonAncestor;
}
const DeclContext *getNominatedNamespace() const {
return Nominated;
}
// Sort by the pointer value of the common ancestor.
struct Comparator {
bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) {
return L.getCommonAncestor() < R.getCommonAncestor();
}
bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) {
return E.getCommonAncestor() < DC;
}
bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) {
return DC < E.getCommonAncestor();
}
};
};
/// A collection of using directives, as used by C++ unqualified
/// lookup.
class UnqualUsingDirectiveSet {
typedef SmallVector<UnqualUsingEntry, 8> ListTy;
ListTy list;
llvm::SmallPtrSet<DeclContext*, 8> visited;
public:
UnqualUsingDirectiveSet() {}
void visitScopeChain(Scope *S, Scope *InnermostFileScope) {
// C++ [namespace.udir]p1:
// During unqualified name lookup, the names appear as if they
// were declared in the nearest enclosing namespace which contains
// both the using-directive and the nominated namespace.
DeclContext *InnermostFileDC
= static_cast<DeclContext*>(InnermostFileScope->getEntity());
assert(InnermostFileDC && InnermostFileDC->isFileContext());
for (; S; S = S->getParent()) {
// C++ [namespace.udir]p1:
// A using-directive shall not appear in class scope, but may
// appear in namespace scope or in block scope.
DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity());
if (Ctx && Ctx->isFileContext()) {
visit(Ctx, Ctx);
} else if (!Ctx || Ctx->isFunctionOrMethod()) {
Scope::udir_iterator I = S->using_directives_begin(),
End = S->using_directives_end();
for (; I != End; ++I)
visit(*I, InnermostFileDC);
}
}
}
// Visits a context and collect all of its using directives
// recursively. Treats all using directives as if they were
// declared in the context.
//
// A given context is only every visited once, so it is important
// that contexts be visited from the inside out in order to get
// the effective DCs right.
void visit(DeclContext *DC, DeclContext *EffectiveDC) {
if (!visited.insert(DC))
return;
addUsingDirectives(DC, EffectiveDC);
}
// Visits a using directive and collects all of its using
// directives recursively. Treats all using directives as if they
// were declared in the effective DC.
void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
DeclContext *NS = UD->getNominatedNamespace();
if (!visited.insert(NS))
return;
addUsingDirective(UD, EffectiveDC);
addUsingDirectives(NS, EffectiveDC);
}
// Adds all the using directives in a context (and those nominated
// by its using directives, transitively) as if they appeared in
// the given effective context.
void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) {
SmallVector<DeclContext*,4> queue;
while (true) {
DeclContext::udir_iterator I, End;
for (llvm::tie(I, End) = DC->getUsingDirectives(); I != End; ++I) {
UsingDirectiveDecl *UD = *I;
DeclContext *NS = UD->getNominatedNamespace();
if (visited.insert(NS)) {
addUsingDirective(UD, EffectiveDC);
queue.push_back(NS);
}
}
if (queue.empty())
return;
DC = queue.back();
queue.pop_back();
}
}
// Add a using directive as if it had been declared in the given
// context. This helps implement C++ [namespace.udir]p3:
// The using-directive is transitive: if a scope contains a
// using-directive that nominates a second namespace that itself
// contains using-directives, the effect is as if the
// using-directives from the second namespace also appeared in
// the first.
void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
// Find the common ancestor between the effective context and
// the nominated namespace.
DeclContext *Common = UD->getNominatedNamespace();
while (!Common->Encloses(EffectiveDC))
Common = Common->getParent();
Common = Common->getPrimaryContext();
list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common));
}
void done() {
std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator());
}
typedef ListTy::const_iterator const_iterator;
const_iterator begin() const { return list.begin(); }
const_iterator end() const { return list.end(); }
std::pair<const_iterator,const_iterator>
getNamespacesFor(DeclContext *DC) const {
return std::equal_range(begin(), end(), DC->getPrimaryContext(),
UnqualUsingEntry::Comparator());
}
};
}
// Retrieve the set of identifier namespaces that correspond to a
// specific kind of name lookup.
static inline unsigned getIDNS(Sema::LookupNameKind NameKind,
bool CPlusPlus,
bool Redeclaration) {
unsigned IDNS = 0;
switch (NameKind) {
case Sema::LookupObjCImplicitSelfParam:
case Sema::LookupOrdinaryName:
case Sema::LookupRedeclarationWithLinkage:
IDNS = Decl::IDNS_Ordinary;
if (CPlusPlus) {
IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace;
if (Redeclaration)
IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend;
}
break;
case Sema::LookupOperatorName:
// Operator lookup is its own crazy thing; it is not the same
// as (e.g.) looking up an operator name for redeclaration.
assert(!Redeclaration && "cannot do redeclaration operator lookup");
IDNS = Decl::IDNS_NonMemberOperator;
break;
case Sema::LookupTagName:
if (CPlusPlus) {
IDNS = Decl::IDNS_Type;
// When looking for a redeclaration of a tag name, we add:
// 1) TagFriend to find undeclared friend decls
// 2) Namespace because they can't "overload" with tag decls.
// 3) Tag because it includes class templates, which can't
// "overload" with tag decls.
if (Redeclaration)
IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace;
} else {
IDNS = Decl::IDNS_Tag;
}
break;
case Sema::LookupLabel:
IDNS = Decl::IDNS_Label;
break;
case Sema::LookupMemberName:
IDNS = Decl::IDNS_Member;
if (CPlusPlus)
IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary;
break;
case Sema::LookupNestedNameSpecifierName:
IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace;
break;
case Sema::LookupNamespaceName:
IDNS = Decl::IDNS_Namespace;
break;
case Sema::LookupUsingDeclName:
IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag
| Decl::IDNS_Member | Decl::IDNS_Using;
break;
case Sema::LookupObjCProtocolName:
IDNS = Decl::IDNS_ObjCProtocol;
break;
case Sema::LookupAnyName:
IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member
| Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol
| Decl::IDNS_Type;
break;
}
return IDNS;
}
void LookupResult::configure() {
IDNS = getIDNS(LookupKind, SemaRef.getLangOpts().CPlusPlus,
isForRedeclaration());
// If we're looking for one of the allocation or deallocation
// operators, make sure that the implicitly-declared new and delete
// operators can be found.
if (!isForRedeclaration()) {
switch (NameInfo.getName().getCXXOverloadedOperator()) {
case OO_New:
case OO_Delete:
case OO_Array_New:
case OO_Array_Delete:
SemaRef.DeclareGlobalNewDelete();
break;
default:
break;
}
}
}
void LookupResult::sanityImpl() const {
// Note that this function is never called by NDEBUG builds. See
// LookupResult::sanity().
assert(ResultKind != NotFound || Decls.size() == 0);
assert(ResultKind != Found || Decls.size() == 1);
assert(ResultKind != FoundOverloaded || Decls.size() > 1 ||
(Decls.size() == 1 &&
isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl())));
assert(ResultKind != FoundUnresolvedValue || sanityCheckUnresolved());
assert(ResultKind != Ambiguous || Decls.size() > 1 ||
(Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects ||
Ambiguity == AmbiguousBaseSubobjectTypes)));
assert((Paths != NULL) == (ResultKind == Ambiguous &&
(Ambiguity == AmbiguousBaseSubobjectTypes ||
Ambiguity == AmbiguousBaseSubobjects)));
}
// Necessary because CXXBasePaths is not complete in Sema.h
void LookupResult::deletePaths(CXXBasePaths *Paths) {
delete Paths;
}
static NamedDecl *getVisibleDecl(NamedDecl *D);
NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
return getVisibleDecl(D);
}
/// Resolves the result kind of this lookup.
void LookupResult::resolveKind() {
unsigned N = Decls.size();
// Fast case: no possible ambiguity.
if (N == 0) {
assert(ResultKind == NotFound || ResultKind == NotFoundInCurrentInstantiation);
return;
}
// If there's a single decl, we need to examine it to decide what
// kind of lookup this is.
if (N == 1) {
NamedDecl *D = (*Decls.begin())->getUnderlyingDecl();
if (isa<FunctionTemplateDecl>(D))
ResultKind = FoundOverloaded;
else if (isa<UnresolvedUsingValueDecl>(D))
ResultKind = FoundUnresolvedValue;
return;
}
// Don't do any extra resolution if we've already resolved as ambiguous.
if (ResultKind == Ambiguous) return;
llvm::SmallPtrSet<NamedDecl*, 16> Unique;
llvm::SmallPtrSet<QualType, 16> UniqueTypes;
bool Ambiguous = false;
bool HasTag = false, HasFunction = false, HasNonFunction = false;
bool HasFunctionTemplate = false, HasUnresolved = false;
unsigned UniqueTagIndex = 0;
unsigned I = 0;
while (I < N) {
NamedDecl *D = Decls[I]->getUnderlyingDecl();
D = cast<NamedDecl>(D->getCanonicalDecl());
// Redeclarations of types via typedef can occur both within a scope
// and, through using declarations and directives, across scopes. There is
// no ambiguity if they all refer to the same type, so unique based on the
// canonical type.
if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) {
if (!TD->getDeclContext()->isRecord()) {
QualType T = SemaRef.Context.getTypeDeclType(TD);
if (!UniqueTypes.insert(SemaRef.Context.getCanonicalType(T))) {
// The type is not unique; pull something off the back and continue
// at this index.
Decls[I] = Decls[--N];
continue;
}
}
}
if (!Unique.insert(D)) {
// If it's not unique, pull something off the back (and
// continue at this index).
Decls[I] = Decls[--N];
continue;
}
// Otherwise, do some decl type analysis and then continue.
if (isa<UnresolvedUsingValueDecl>(D)) {
HasUnresolved = true;
} else if (isa<TagDecl>(D)) {
if (HasTag)
Ambiguous = true;
UniqueTagIndex = I;
HasTag = true;
} else if (isa<FunctionTemplateDecl>(D)) {
HasFunction = true;
HasFunctionTemplate = true;
} else if (isa<FunctionDecl>(D)) {
HasFunction = true;
} else {
if (HasNonFunction)
Ambiguous = true;
HasNonFunction = true;
}
I++;
}
// C++ [basic.scope.hiding]p2:
// A class name or enumeration name can be hidden by the name of
// an object, function, or enumerator declared in the same
// scope. If a class or enumeration name and an object, function,
// or enumerator are declared in the same scope (in any order)
// with the same name, the class or enumeration name is hidden
// wherever the object, function, or enumerator name is visible.
// But it's still an error if there are distinct tag types found,
// even if they're not visible. (ref?)
if (HideTags && HasTag && !Ambiguous &&
(HasFunction || HasNonFunction || HasUnresolved)) {
if (Decls[UniqueTagIndex]->getDeclContext()->getRedeclContext()->Equals(
Decls[UniqueTagIndex? 0 : N-1]->getDeclContext()->getRedeclContext()))
Decls[UniqueTagIndex] = Decls[--N];
else
Ambiguous = true;
}
Decls.set_size(N);
if (HasNonFunction && (HasFunction || HasUnresolved))
Ambiguous = true;
if (Ambiguous)
setAmbiguous(LookupResult::AmbiguousReference);
else if (HasUnresolved)
ResultKind = LookupResult::FoundUnresolvedValue;
else if (N > 1 || HasFunctionTemplate)
ResultKind = LookupResult::FoundOverloaded;
else
ResultKind = LookupResult::Found;
}
void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) {
CXXBasePaths::const_paths_iterator I, E;
DeclContext::lookup_iterator DI, DE;
for (I = P.begin(), E = P.end(); I != E; ++I)
for (llvm::tie(DI,DE) = I->Decls; DI != DE; ++DI)
addDecl(*DI);
}
void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) {
Paths = new CXXBasePaths;
Paths->swap(P);
addDeclsFromBasePaths(*Paths);
resolveKind();
setAmbiguous(AmbiguousBaseSubobjects);
}
void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) {
Paths = new CXXBasePaths;
Paths->swap(P);
addDeclsFromBasePaths(*Paths);
resolveKind();
setAmbiguous(AmbiguousBaseSubobjectTypes);
}
void LookupResult::print(raw_ostream &Out) {
Out << Decls.size() << " result(s)";
if (isAmbiguous()) Out << ", ambiguous";
if (Paths) Out << ", base paths present";
for (iterator I = begin(), E = end(); I != E; ++I) {
Out << "\n";
(*I)->print(Out, 2);
}
}
/// \brief Lookup a builtin function, when name lookup would otherwise
/// fail.
static bool LookupBuiltin(Sema &S, LookupResult &R) {
Sema::LookupNameKind NameKind = R.getLookupKind();
// If we didn't find a use of this identifier, and if the identifier
// corresponds to a compiler builtin, create the decl object for the builtin
// now, injecting it into translation unit scope, and return it.
if (NameKind == Sema::LookupOrdinaryName ||
NameKind == Sema::LookupRedeclarationWithLinkage) {
IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo();
if (II) {
// If this is a builtin on this (or all) targets, create the decl.
if (unsigned BuiltinID = II->getBuiltinID()) {
// In C++, we don't have any predefined library functions like
// 'malloc'. Instead, we'll just error.
if (S.getLangOpts().CPlusPlus &&
S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
return false;
if (NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II,
BuiltinID, S.TUScope,
R.isForRedeclaration(),
R.getNameLoc())) {
R.addDecl(D);
return true;
}
if (R.isForRedeclaration()) {
// If we're redeclaring this function anyway, forget that
// this was a builtin at all.
S.Context.BuiltinInfo.ForgetBuiltin(BuiltinID, S.Context.Idents);
}
return false;
}
}
}
return false;
}
/// \brief Determine whether we can declare a special member function within
/// the class at this point.
static bool CanDeclareSpecialMemberFunction(ASTContext &Context,
const CXXRecordDecl *Class) {
// We need to have a definition for the class.
if (!Class->getDefinition() || Class->isDependentContext())
return false;
// We can't be in the middle of defining the class.
if (const RecordType *RecordTy
= Context.getTypeDeclType(Class)->getAs<RecordType>())
return !RecordTy->isBeingDefined();
return false;
}
void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) {
if (!CanDeclareSpecialMemberFunction(Context, Class))
return;
// If the default constructor has not yet been declared, do so now.
if (Class->needsImplicitDefaultConstructor())
DeclareImplicitDefaultConstructor(Class);
// If the copy constructor has not yet been declared, do so now.
if (!Class->hasDeclaredCopyConstructor())
DeclareImplicitCopyConstructor(Class);
// If the copy assignment operator has not yet been declared, do so now.
if (!Class->hasDeclaredCopyAssignment())
DeclareImplicitCopyAssignment(Class);
if (getLangOpts().CPlusPlus0x) {
// If the move constructor has not yet been declared, do so now.
if (Class->needsImplicitMoveConstructor())
DeclareImplicitMoveConstructor(Class); // might not actually do it
// If the move assignment operator has not yet been declared, do so now.
if (Class->needsImplicitMoveAssignment())
DeclareImplicitMoveAssignment(Class); // might not actually do it
}
// If the destructor has not yet been declared, do so now.
if (!Class->hasDeclaredDestructor())
DeclareImplicitDestructor(Class);
}
/// \brief Determine whether this is the name of an implicitly-declared
/// special member function.
static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) {
switch (Name.getNameKind()) {
case DeclarationName::CXXConstructorName:
case DeclarationName::CXXDestructorName:
return true;
case DeclarationName::CXXOperatorName:
return Name.getCXXOverloadedOperator() == OO_Equal;
default:
break;
}
return false;
}
/// \brief If there are any implicit member functions with the given name
/// that need to be declared in the given declaration context, do so.
static void DeclareImplicitMemberFunctionsWithName(Sema &S,
DeclarationName Name,
const DeclContext *DC) {
if (!DC)
return;
switch (Name.getNameKind()) {
case DeclarationName::CXXConstructorName:
if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
if (Record->getDefinition() &&
CanDeclareSpecialMemberFunction(S.Context, Record)) {
CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
if (Record->needsImplicitDefaultConstructor())
S.DeclareImplicitDefaultConstructor(Class);
if (!Record->hasDeclaredCopyConstructor())
S.DeclareImplicitCopyConstructor(Class);
if (S.getLangOpts().CPlusPlus0x &&
Record->needsImplicitMoveConstructor())
S.DeclareImplicitMoveConstructor(Class);
}
break;
case DeclarationName::CXXDestructorName:
if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
if (Record->getDefinition() && !Record->hasDeclaredDestructor() &&
CanDeclareSpecialMemberFunction(S.Context, Record))
S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record));
break;
case DeclarationName::CXXOperatorName:
if (Name.getCXXOverloadedOperator() != OO_Equal)
break;
if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) {
if (Record->getDefinition() &&
CanDeclareSpecialMemberFunction(S.Context, Record)) {
CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
if (!Record->hasDeclaredCopyAssignment())
S.DeclareImplicitCopyAssignment(Class);
if (S.getLangOpts().CPlusPlus0x &&
Record->needsImplicitMoveAssignment())
S.DeclareImplicitMoveAssignment(Class);
}
}
break;
default:
break;
}
}
// Adds all qualifying matches for a name within a decl context to the
// given lookup result. Returns true if any matches were found.
static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
bool Found = false;
// Lazily declare C++ special member functions.
if (S.getLangOpts().CPlusPlus)
DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), DC);
// Perform lookup into this declaration context.
DeclContext::lookup_const_iterator I, E;
for (llvm::tie(I, E) = DC->lookup(R.getLookupName()); I != E; ++I) {
NamedDecl *D = *I;
if ((D = R.getAcceptableDecl(D))) {
R.addDecl(D);
Found = true;
}
}
if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R))
return true;
if (R.getLookupName().getNameKind()
!= DeclarationName::CXXConversionFunctionName ||
R.getLookupName().getCXXNameType()->isDependentType() ||
!isa<CXXRecordDecl>(DC))
return Found;
// C++ [temp.mem]p6:
// A specialization of a conversion function template is not found by
// name lookup. Instead, any conversion function templates visible in the
// context of the use are considered. [...]
const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
if (!Record->isCompleteDefinition())
return Found;
const UnresolvedSetImpl *Unresolved = Record->getConversionFunctions();
for (UnresolvedSetImpl::iterator U = Unresolved->begin(),
UEnd = Unresolved->end(); U != UEnd; ++U) {
FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
if (!ConvTemplate)
continue;
// When we're performing lookup for the purposes of redeclaration, just
// add the conversion function template. When we deduce template
// arguments for specializations, we'll end up unifying the return
// type of the new declaration with the type of the function template.
if (R.isForRedeclaration()) {
R.addDecl(ConvTemplate);
Found = true;
continue;
}
// C++ [temp.mem]p6:
// [...] For each such operator, if argument deduction succeeds
// (14.9.2.3), the resulting specialization is used as if found by
// name lookup.
//
// When referencing a conversion function for any purpose other than
// a redeclaration (such that we'll be building an expression with the
// result), perform template argument deduction and place the
// specialization into the result set. We do this to avoid forcing all
// callers to perform special deduction for conversion functions.
TemplateDeductionInfo Info(R.getSema().Context, R.getNameLoc());
FunctionDecl *Specialization = 0;
const FunctionProtoType *ConvProto
= ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
assert(ConvProto && "Nonsensical conversion function template type");
// Compute the type of the function that we would expect the conversion
// function to have, if it were to match the name given.
// FIXME: Calling convention!
FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo();
EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_Default);
EPI.ExceptionSpecType = EST_None;
EPI.NumExceptions = 0;
QualType ExpectedType
= R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(),
0, 0, EPI);
// Perform template argument deduction against the type that we would
// expect the function to have.
if (R.getSema().DeduceTemplateArguments(ConvTemplate, 0, ExpectedType,
Specialization, Info)
== Sema::TDK_Success) {
R.addDecl(Specialization);
Found = true;
}
}
return Found;
}
// Performs C++ unqualified lookup into the given file context.
static bool
CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context,
DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
// Perform direct name lookup into the LookupCtx.
bool Found = LookupDirect(S, R, NS);
// Perform direct name lookup into the namespaces nominated by the
// using directives whose common ancestor is this namespace.
UnqualUsingDirectiveSet::const_iterator UI, UEnd;
llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(NS);
for (; UI != UEnd; ++UI)
if (LookupDirect(S, R, UI->getNominatedNamespace()))
Found = true;
R.resolveKind();
return Found;
}
static bool isNamespaceOrTranslationUnitScope(Scope *S) {
if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity()))
return Ctx->isFileContext();
return false;
}
// Find the next outer declaration context from this scope. This
// routine actually returns the semantic outer context, which may
// differ from the lexical context (encoded directly in the Scope
// stack) when we are parsing a member of a class template. In this
// case, the second element of the pair will be true, to indicate that
// name lookup should continue searching in this semantic context when
// it leaves the current template parameter scope.
static std::pair<DeclContext *, bool> findOuterContext(Scope *S) {
DeclContext *DC = static_cast<DeclContext *>(S->getEntity());
DeclContext *Lexical = 0;
for (Scope *OuterS = S->getParent(); OuterS;
OuterS = OuterS->getParent()) {
if (OuterS->getEntity()) {
Lexical = static_cast<DeclContext *>(OuterS->getEntity());
break;
}
}
// C++ [temp.local]p8:
// In the definition of a member of a class template that appears
// outside of the namespace containing the class template
// definition, the name of a template-parameter hides the name of
// a member of this namespace.
//
// Example:
//
// namespace N {
// class C { };
//
// template<class T> class B {
// void f(T);
// };
// }
//
// template<class C> void N::B<C>::f(C) {
// C b; // C is the template parameter, not N::C
// }
//
// In this example, the lexical context we return is the
// TranslationUnit, while the semantic context is the namespace N.
if (!Lexical || !DC || !S->getParent() ||
!S->getParent()->isTemplateParamScope())
return std::make_pair(Lexical, false);
// Find the outermost template parameter scope.
// For the example, this is the scope for the template parameters of
// template<class C>.
Scope *OutermostTemplateScope = S->getParent();
while (OutermostTemplateScope->getParent() &&
OutermostTemplateScope->getParent()->isTemplateParamScope())
OutermostTemplateScope = OutermostTemplateScope->getParent();
// Find the namespace context in which the original scope occurs. In
// the example, this is namespace N.
DeclContext *Semantic = DC;
while (!Semantic->isFileContext())
Semantic = Semantic->getParent();
// Find the declaration context just outside of the template
// parameter scope. This is the context in which the template is
// being lexically declaration (a namespace context). In the
// example, this is the global scope.
if (Lexical->isFileContext() && !Lexical->Equals(Semantic) &&
Lexical->Encloses(Semantic))
return std::make_pair(Semantic, true);
return std::make_pair(Lexical, false);
}
bool Sema::CppLookupName(LookupResult &R, Scope *S) {
assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
DeclarationName Name = R.getLookupName();
// If this is the name of an implicitly-declared special member function,
// go through the scope stack to implicitly declare
if (isImplicitlyDeclaredMemberFunctionName(Name)) {
for (Scope *PreS = S; PreS; PreS = PreS->getParent())
if (DeclContext *DC = static_cast<DeclContext *>(PreS->getEntity()))
DeclareImplicitMemberFunctionsWithName(*this, Name, DC);
}
// Implicitly declare member functions with the name we're looking for, if in
// fact we are in a scope where it matters.
Scope *Initial = S;
IdentifierResolver::iterator
I = IdResolver.begin(Name),
IEnd = IdResolver.end();
// First we lookup local scope.
// We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
// ...During unqualified name lookup (3.4.1), the names appear as if
// they were declared in the nearest enclosing namespace which contains
// both the using-directive and the nominated namespace.
// [Note: in this context, "contains" means "contains directly or
// indirectly".
//
// For example:
// namespace A { int i; }
// void foo() {
// int i;
// {
// using namespace A;
// ++i; // finds local 'i', A::i appears at global scope
// }
// }
//
DeclContext *OutsideOfTemplateParamDC = 0;
for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity());
// Check whether the IdResolver has anything in this scope.
bool Found = false;
for (; I != IEnd && S->isDeclScope(*I); ++I) {
if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
Found = true;
R.addDecl(ND);
}
}
if (Found) {
R.resolveKind();
if (S->isClassScope())
if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx))
R.setNamingClass(Record);
return true;
}
if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
S->getParent() && !S->getParent()->isTemplateParamScope()) {
// We've just searched the last template parameter scope and
// found nothing, so look into the contexts between the
// lexical and semantic declaration contexts returned by
// findOuterContext(). This implements the name lookup behavior
// of C++ [temp.local]p8.
Ctx = OutsideOfTemplateParamDC;
OutsideOfTemplateParamDC = 0;
}
if (Ctx) {
DeclContext *OuterCtx;
bool SearchAfterTemplateScope;
llvm::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
if (SearchAfterTemplateScope)
OutsideOfTemplateParamDC = OuterCtx;
for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
// We do not directly look into transparent contexts, since
// those entities will be found in the nearest enclosing
// non-transparent context.
if (Ctx->isTransparentContext())
continue;
// We do not look directly into function or method contexts,
// since all of the local variables and parameters of the
// function/method are present within the Scope.
if (Ctx->isFunctionOrMethod()) {
// If we have an Objective-C instance method, look for ivars
// in the corresponding interface.
if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
ObjCInterfaceDecl *ClassDeclared;
if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
Name.getAsIdentifierInfo(),
ClassDeclared)) {
if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) {
R.addDecl(ND);
R.resolveKind();
return true;
}
}
}
}
continue;
}
// Perform qualified name lookup into this context.
// FIXME: In some cases, we know that every name that could be found by
// this qualified name lookup will also be on the identifier chain. For
// example, inside a class without any base classes, we never need to
// perform qualified lookup because all of the members are on top of the
// identifier chain.
if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
return true;
}
}
}
// Stop if we ran out of scopes.
// FIXME: This really, really shouldn't be happening.
if (!S) return false;
// If we are looking for members, no need to look into global/namespace scope.
if (R.getLookupKind() == LookupMemberName)
return false;
// Collect UsingDirectiveDecls in all scopes, and recursively all
// nominated namespaces by those using-directives.
//
// FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
// don't build it for each lookup!
UnqualUsingDirectiveSet UDirs;
UDirs.visitScopeChain(Initial, S);
UDirs.done();
// Lookup namespace scope, and global scope.
// Unqualified name lookup in C++ requires looking into scopes
// that aren't strictly lexical, and therefore we walk through the
// context as well as walking through the scopes.
for (; S; S = S->getParent()) {
// Check whether the IdResolver has anything in this scope.
bool Found = false;
for (; I != IEnd && S->isDeclScope(*I); ++I) {
if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
// We found something. Look for anything else in our scope
// with this same name and in an acceptable identifier
// namespace, so that we can construct an overload set if we
// need to.
Found = true;
R.addDecl(ND);
}
}
if (Found && S->isTemplateParamScope()) {
R.resolveKind();
return true;
}
DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity());
if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
S->getParent() && !S->getParent()->isTemplateParamScope()) {
// We've just searched the last template parameter scope and
// found nothing, so look into the contexts between the
// lexical and semantic declaration contexts returned by
// findOuterContext(). This implements the name lookup behavior
// of C++ [temp.local]p8.
Ctx = OutsideOfTemplateParamDC;
OutsideOfTemplateParamDC = 0;
}
if (Ctx) {
DeclContext *OuterCtx;
bool SearchAfterTemplateScope;
llvm::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
if (SearchAfterTemplateScope)
OutsideOfTemplateParamDC = OuterCtx;
for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
// We do not directly look into transparent contexts, since
// those entities will be found in the nearest enclosing
// non-transparent context.
if (Ctx->isTransparentContext())
continue;
// If we have a context, and it's not a context stashed in the
// template parameter scope for an out-of-line definition, also
// look into that context.
if (!(Found && S && S->isTemplateParamScope())) {
assert(Ctx->isFileContext() &&
"We should have been looking only at file context here already.");
// Look into context considering using-directives.
if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
Found = true;
}
if (Found) {
R.resolveKind();
return true;
}
if (R.isForRedeclaration() && !Ctx->isTransparentContext())
return false;
}
}
if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
return false;
}
return !R.empty();
}
/// \brief Retrieve the visible declaration corresponding to D, if any.
///
/// This routine determines whether the declaration D is visible in the current
/// module, with the current imports. If not, it checks whether any
/// redeclaration of D is visible, and if so, returns that declaration.
///
/// \returns D, or a visible previous declaration of D, whichever is more recent
/// and visible. If no declaration of D is visible, returns null.
static NamedDecl *getVisibleDecl(NamedDecl *D) {
if (LookupResult::isVisible(D))
return D;
for (Decl::redecl_iterator RD = D->redecls_begin(), RDEnd = D->redecls_end();
RD != RDEnd; ++RD) {
if (NamedDecl *ND = dyn_cast<NamedDecl>(*RD)) {
if (LookupResult::isVisible(ND))
return ND;
}
}
return 0;
}
/// @brief Perform unqualified name lookup starting from a given
/// scope.
///
/// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
/// used to find names within the current scope. For example, 'x' in
/// @code
/// int x;
/// int f() {
/// return x; // unqualified name look finds 'x' in the global scope
/// }
/// @endcode
///
/// Different lookup criteria can find different names. For example, a
/// particular scope can have both a struct and a function of the same
/// name, and each can be found by certain lookup criteria. For more
/// information about lookup criteria, see the documentation for the
/// class LookupCriteria.
///
/// @param S The scope from which unqualified name lookup will
/// begin. If the lookup criteria permits, name lookup may also search
/// in the parent scopes.
///
/// @param [in,out] R Specifies the lookup to perform (e.g., the name to
/// look up and the lookup kind), and is updated with the results of lookup
/// including zero or more declarations and possibly additional information
/// used to diagnose ambiguities.
///
/// @returns \c true if lookup succeeded and false otherwise.
bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
DeclarationName Name = R.getLookupName();
if (!Name) return false;
LookupNameKind NameKind = R.getLookupKind();
if (!getLangOpts().CPlusPlus) {
// Unqualified name lookup in C/Objective-C is purely lexical, so
// search in the declarations attached to the name.
if (NameKind == Sema::LookupRedeclarationWithLinkage) {
// Find the nearest non-transparent declaration scope.
while (!(S->getFlags() & Scope::DeclScope) ||
(S->getEntity() &&
static_cast<DeclContext *>(S->getEntity())
->isTransparentContext()))
S = S->getParent();
}
unsigned IDNS = R.getIdentifierNamespace();
// Scan up the scope chain looking for a decl that matches this
// identifier that is in the appropriate namespace. This search
// should not take long, as shadowing of names is uncommon, and
// deep shadowing is extremely uncommon.
bool LeftStartingScope = false;
for (IdentifierResolver::iterator I = IdResolver.begin(Name),
IEnd = IdResolver.end();
I != IEnd; ++I)
if ((*I)->isInIdentifierNamespace(IDNS)) {
if (NameKind == LookupRedeclarationWithLinkage) {
// Determine whether this (or a previous) declaration is
// out-of-scope.
if (!LeftStartingScope && !S->isDeclScope(*I))
LeftStartingScope = true;
// If we found something outside of our starting scope that
// does not have linkage, skip it.
if (LeftStartingScope && !((*I)->hasLinkage()))
continue;
}
else if (NameKind == LookupObjCImplicitSelfParam &&
!isa<ImplicitParamDecl>(*I))
continue;
// If this declaration is module-private and it came from an AST
// file, we can't see it.
NamedDecl *D = R.isHiddenDeclarationVisible()? *I : getVisibleDecl(*I);
if (!D)
continue;
R.addDecl(D);
// Check whether there are any other declarations with the same name
// and in the same scope.
if (I != IEnd) {
// Find the scope in which this declaration was declared (if it
// actually exists in a Scope).
while (S && !S->isDeclScope(D))
S = S->getParent();
// If the scope containing the declaration is the translation unit,
// then we'll need to perform our checks based on the matching
// DeclContexts rather than matching scopes.
if (S && isNamespaceOrTranslationUnitScope(S))
S = 0;
// Compute the DeclContext, if we need it.
DeclContext *DC = 0;
if (!S)
DC = (*I)->getDeclContext()->getRedeclContext();
IdentifierResolver::iterator LastI = I;
for (++LastI; LastI != IEnd; ++LastI) {
if (S) {
// Match based on scope.
if (!S->isDeclScope(*LastI))
break;
} else {
// Match based on DeclContext.
DeclContext *LastDC
= (*LastI)->getDeclContext()->getRedeclContext();
if (!LastDC->Equals(DC))
break;
}
// If the declaration isn't in the right namespace, skip it.
if (!(*LastI)->isInIdentifierNamespace(IDNS))
continue;
D = R.isHiddenDeclarationVisible()? *LastI : getVisibleDecl(*LastI);
if (D)
R.addDecl(D);
}
R.resolveKind();
}
return true;
}
} else {
// Perform C++ unqualified name lookup.
if (CppLookupName(R, S))
return true;
}
// If we didn't find a use of this identifier, and if the identifier
// corresponds to a compiler builtin, create the decl object for the builtin
// now, injecting it into translation unit scope, and return it.
if (AllowBuiltinCreation && LookupBuiltin(*this, R))
return true;
// If we didn't find a use of this identifier, the ExternalSource
// may be able to handle the situation.
// Note: some lookup failures are expected!
// See e.g. R.isForRedeclaration().
return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
}
/// @brief Perform qualified name lookup in the namespaces nominated by
/// using directives by the given context.
///
/// C++98 [namespace.qual]p2:
/// Given X::m (where X is a user-declared namespace), or given \::m
/// (where X is the global namespace), let S be the set of all
/// declarations of m in X and in the transitive closure of all
/// namespaces nominated by using-directives in X and its used
/// namespaces, except that using-directives are ignored in any
/// namespace, including X, directly containing one or more
/// declarations of m. No namespace is searched more than once in
/// the lookup of a name. If S is the empty set, the program is
/// ill-formed. Otherwise, if S has exactly one member, or if the
/// context of the reference is a using-declaration
/// (namespace.udecl), S is the required set of declarations of
/// m. Otherwise if the use of m is not one that allows a unique
/// declaration to be chosen from S, the program is ill-formed.
///
/// C++98 [namespace.qual]p5:
/// During the lookup of a qualified namespace member name, if the
/// lookup finds more than one declaration of the member, and if one
/// declaration introduces a class name or enumeration name and the
/// other declarations either introduce the same object, the same
/// enumerator or a set of functions, the non-type name hides the
/// class or enumeration name if and only if the declarations are
/// from the same namespace; otherwise (the declarations are from
/// different namespaces), the program is ill-formed.
static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R,
DeclContext *StartDC) {
assert(StartDC->isFileContext() && "start context is not a file context");
DeclContext::udir_iterator I = StartDC->using_directives_begin();
DeclContext::udir_iterator E = StartDC->using_directives_end();
if (I == E) return false;
// We have at least added all these contexts to the queue.
llvm::SmallPtrSet<DeclContext*, 8> Visited;
Visited.insert(StartDC);
// We have not yet looked into these namespaces, much less added
// their "using-children" to the queue.
SmallVector<NamespaceDecl*, 8> Queue;
// We have already looked into the initial namespace; seed the queue
// with its using-children.
for (; I != E; ++I) {
NamespaceDecl *ND = (*I)->getNominatedNamespace()->getOriginalNamespace();
if (Visited.insert(ND))
Queue.push_back(ND);
}
// The easiest way to implement the restriction in [namespace.qual]p5
// is to check whether any of the individual results found a tag
// and, if so, to declare an ambiguity if the final result is not
// a tag.
bool FoundTag = false;
bool FoundNonTag = false;
LookupResult LocalR(LookupResult::Temporary, R);
bool Found = false;
while (!Queue.empty()) {
NamespaceDecl *ND = Queue.back();
Queue.pop_back();
// We go through some convolutions here to avoid copying results
// between LookupResults.
bool UseLocal = !R.empty();
LookupResult &DirectR = UseLocal ? LocalR : R;
bool FoundDirect = LookupDirect(S, DirectR, ND);
if (FoundDirect) {
// First do any local hiding.
DirectR.resolveKind();
// If the local result is a tag, remember that.
if (DirectR.isSingleTagDecl())
FoundTag = true;
else
FoundNonTag = true;
// Append the local results to the total results if necessary.
if (UseLocal) {
R.addAllDecls(LocalR);
LocalR.clear();
}
}
// If we find names in this namespace, ignore its using directives.
if (FoundDirect) {
Found = true;
continue;
}
for (llvm::tie(I,E) = ND->getUsingDirectives(); I != E; ++I) {
NamespaceDecl *Nom = (*I)->getNominatedNamespace();
if (Visited.insert(Nom))
Queue.push_back(Nom);
}
}
if (Found) {
if (FoundTag && FoundNonTag)
R.setAmbiguousQualifiedTagHiding();
else
R.resolveKind();
}
return Found;
}
/// \brief Callback that looks for any member of a class with the given name.
static bool LookupAnyMember(const CXXBaseSpecifier *Specifier,
CXXBasePath &Path,
void *Name) {
RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
DeclarationName N = DeclarationName::getFromOpaquePtr(Name);
Path.Decls = BaseRecord->lookup(N);
return Path.Decls.first != Path.Decls.second;
}
/// \brief Determine whether the given set of member declarations contains only
/// static members, nested types, and enumerators.
template<typename InputIterator>
static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) {
Decl *D = (*First)->getUnderlyingDecl();
if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D))
return true;
if (isa<CXXMethodDecl>(D)) {
// Determine whether all of the methods are static.
bool AllMethodsAreStatic = true;
for(; First != Last; ++First) {
D = (*First)->getUnderlyingDecl();
if (!isa<CXXMethodDecl>(D)) {
assert(isa<TagDecl>(D) && "Non-function must be a tag decl");
break;
}
if (!cast<CXXMethodDecl>(D)->isStatic()) {
AllMethodsAreStatic = false;
break;
}
}
if (AllMethodsAreStatic)
return true;
}
return false;
}
/// \brief Perform qualified name lookup into a given context.
///
/// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
/// names when the context of those names is explicit specified, e.g.,
/// "std::vector" or "x->member", or as part of unqualified name lookup.
///
/// Different lookup criteria can find different names. For example, a
/// particular scope can have both a struct and a function of the same
/// name, and each can be found by certain lookup criteria. For more
/// information about lookup criteria, see the documentation for the
/// class LookupCriteria.
///
/// \param R captures both the lookup criteria and any lookup results found.
///
/// \param LookupCtx The context in which qualified name lookup will
/// search. If the lookup criteria permits, name lookup may also search
/// in the parent contexts or (for C++ classes) base classes.
///
/// \param InUnqualifiedLookup true if this is qualified name lookup that
/// occurs as part of unqualified name lookup.
///
/// \returns true if lookup succeeded, false if it failed.
bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
bool InUnqualifiedLookup) {
assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
if (!R.getLookupName())
return false;
// Make sure that the declaration context is complete.
assert((!isa<TagDecl>(LookupCtx) ||
LookupCtx->isDependentContext() ||
cast<TagDecl>(LookupCtx)->isCompleteDefinition() ||
cast<TagDecl>(LookupCtx)->isBeingDefined()) &&
"Declaration context must already be complete!");
// Perform qualified name lookup into the LookupCtx.
if (LookupDirect(*this, R, LookupCtx)) {
R.resolveKind();
if (isa<CXXRecordDecl>(LookupCtx))
R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
return true;
}
// Don't descend into implied contexts for redeclarations.
// C++98 [namespace.qual]p6:
// In a declaration for a namespace member in which the
// declarator-id is a qualified-id, given that the qualified-id
// for the namespace member has the form
// nested-name-specifier unqualified-id
// the unqualified-id shall name a member of the namespace
// designated by the nested-name-specifier.
// See also [class.mfct]p5 and [class.static.data]p2.
if (R.isForRedeclaration())
return false;
// If this is a namespace, look it up in the implied namespaces.
if (LookupCtx->isFileContext())
return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
// If this isn't a C++ class, we aren't allowed to look into base
// classes, we're done.
CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
if (!LookupRec || !LookupRec->getDefinition())
return false;
// If we're performing qualified name lookup into a dependent class,
// then we are actually looking into a current instantiation. If we have any
// dependent base classes, then we either have to delay lookup until
// template instantiation time (at which point all bases will be available)
// or we have to fail.
if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
LookupRec->hasAnyDependentBases()) {
R.setNotFoundInCurrentInstantiation();
return false;
}
// Perform lookup into our base classes.
CXXBasePaths Paths;
Paths.setOrigin(LookupRec);
// Look for this member in our base classes
CXXRecordDecl::BaseMatchesCallback *BaseCallback = 0;
switch (R.getLookupKind()) {
case LookupObjCImplicitSelfParam:
case LookupOrdinaryName:
case LookupMemberName:
case LookupRedeclarationWithLinkage:
BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
break;
case LookupTagName:
BaseCallback = &CXXRecordDecl::FindTagMember;
break;
case LookupAnyName:
BaseCallback = &LookupAnyMember;
break;
case LookupUsingDeclName:
// This lookup is for redeclarations only.
case LookupOperatorName:
case LookupNamespaceName:
case LookupObjCProtocolName:
case LookupLabel:
// These lookups will never find a member in a C++ class (or base class).
return false;
case LookupNestedNameSpecifierName:
BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember;
break;
}
if (!LookupRec->lookupInBases(BaseCallback,
R.getLookupName().getAsOpaquePtr(), Paths))
return false;
R.setNamingClass(LookupRec);
// C++ [class.member.lookup]p2:
// [...] If the resulting set of declarations are not all from
// sub-objects of the same type, or the set has a nonstatic member
// and includes members from distinct sub-objects, there is an
// ambiguity and the program is ill-formed. Otherwise that set is
// the result of the lookup.
QualType SubobjectType;
int SubobjectNumber = 0;
AccessSpecifier SubobjectAccess = AS_none;
for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
Path != PathEnd; ++Path) {
const CXXBasePathElement &PathElement = Path->back();
// Pick the best (i.e. most permissive i.e. numerically lowest) access
// across all paths.
SubobjectAccess = std::min(SubobjectAccess, Path->Access);
// Determine whether we're looking at a distinct sub-object or not.
if (SubobjectType.isNull()) {
// This is the first subobject we've looked at. Record its type.
SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
SubobjectNumber = PathElement.SubobjectNumber;
continue;
}
if (SubobjectType
!= Context.getCanonicalType(PathElement.Base->getType())) {
// We found members of the given name in two subobjects of
// different types. If the declaration sets aren't the same, this
// this lookup is ambiguous.
if (HasOnlyStaticMembers(Path->Decls.first, Path->Decls.second)) {
CXXBasePaths::paths_iterator FirstPath = Paths.begin();
DeclContext::lookup_iterator FirstD = FirstPath->Decls.first;
DeclContext::lookup_iterator CurrentD = Path->Decls.first;
while (FirstD != FirstPath->Decls.second &&
CurrentD != Path->Decls.second) {
if ((*FirstD)->getUnderlyingDecl()->getCanonicalDecl() !=
(*CurrentD)->getUnderlyingDecl()->getCanonicalDecl())
break;
++FirstD;
++CurrentD;
}
if (FirstD == FirstPath->Decls.second &&
CurrentD == Path->Decls.second)
continue;
}
R.setAmbiguousBaseSubobjectTypes(Paths);
return true;
}
if (SubobjectNumber != PathElement.SubobjectNumber) {
// We have a different subobject of the same type.
// C++ [class.member.lookup]p5:
// A static member, a nested type or an enumerator defined in
// a base class T can unambiguously be found even if an object
// has more than one base class subobject of type T.
if (HasOnlyStaticMembers(Path->Decls.first, Path->Decls.second))
continue;
// We have found a nonstatic member name in multiple, distinct
// subobjects. Name lookup is ambiguous.
R.setAmbiguousBaseSubobjects(Paths);
return true;
}
}
// Lookup in a base class succeeded; return these results.
DeclContext::lookup_iterator I, E;
for (llvm::tie(I,E) = Paths.front().Decls; I != E; ++I) {
NamedDecl *D = *I;
AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
D->getAccess());
R.addDecl(D, AS);
}
R.resolveKind();
return true;
}
/// @brief Performs name lookup for a name that was parsed in the
/// source code, and may contain a C++ scope specifier.
///
/// This routine is a convenience routine meant to be called from
/// contexts that receive a name and an optional C++ scope specifier
/// (e.g., "N::M::x"). It will then perform either qualified or
/// unqualified name lookup (with LookupQualifiedName or LookupName,
/// respectively) on the given name and return those results.
///
/// @param S The scope from which unqualified name lookup will
/// begin.
///
/// @param SS An optional C++ scope-specifier, e.g., "::N::M".
///
/// @param EnteringContext Indicates whether we are going to enter the
/// context of the scope-specifier SS (if present).
///
/// @returns True if any decls were found (but possibly ambiguous)
bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
bool AllowBuiltinCreation, bool EnteringContext) {
if (SS && SS->isInvalid()) {
// When the scope specifier is invalid, don't even look for
// anything.
return false;
}
if (SS && SS->isSet()) {
if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
// We have resolved the scope specifier to a particular declaration
// contex, and will perform name lookup in that context.
if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC))
return false;
R.setContextRange(SS->getRange());
return LookupQualifiedName(R, DC);
}
// We could not resolve the scope specified to a specific declaration
// context, which means that SS refers to an unknown specialization.
// Name lookup can't find anything in this case.
R.setNotFoundInCurrentInstantiation();
R.setContextRange(SS->getRange());
return false;
}
// Perform unqualified name lookup starting in the given scope.
return LookupName(R, S, AllowBuiltinCreation);
}
/// \brief Produce a diagnostic describing the ambiguity that resulted
/// from name lookup.
///
/// \param Result The result of the ambiguous lookup to be diagnosed.
///
/// \returns true
bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
DeclarationName Name = Result.getLookupName();
SourceLocation NameLoc = Result.getNameLoc();
SourceRange LookupRange = Result.getContextRange();
switch (Result.getAmbiguityKind()) {
case LookupResult::AmbiguousBaseSubobjects: {
CXXBasePaths *Paths = Result.getBasePaths();
QualType SubobjectType = Paths->front().back().Base->getType();
Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
<< Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
<< LookupRange;
DeclContext::lookup_iterator Found = Paths->front().Decls.first;
while (isa<CXXMethodDecl>(*Found) &&
cast<CXXMethodDecl>(*Found)->isStatic())
++Found;
Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
return true;
}
case LookupResult::AmbiguousBaseSubobjectTypes: {
Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
<< Name << LookupRange;
CXXBasePaths *Paths = Result.getBasePaths();
std::set<Decl *> DeclsPrinted;
for (CXXBasePaths::paths_iterator Path = Paths->begin(),
PathEnd = Paths->end();
Path != PathEnd; ++Path) {
Decl *D = *Path->Decls.first;
if (DeclsPrinted.insert(D).second)
Diag(D->getLocation(), diag::note_ambiguous_member_found);
}
return true;
}
case LookupResult::AmbiguousTagHiding: {
Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
llvm::SmallPtrSet<NamedDecl*,8> TagDecls;
LookupResult::iterator DI, DE = Result.end();
for (DI = Result.begin(); DI != DE; ++DI)
if (TagDecl *TD = dyn_cast<TagDecl>(*DI)) {
TagDecls.insert(TD);
Diag(TD->getLocation(), diag::note_hidden_tag);
}
for (DI = Result.begin(); DI != DE; ++DI)
if (!isa<TagDecl>(*DI))
Diag((*DI)->getLocation(), diag::note_hiding_object);
// For recovery purposes, go ahead and implement the hiding.
LookupResult::Filter F = Result.makeFilter();
while (F.hasNext()) {
if (TagDecls.count(F.next()))
F.erase();
}
F.done();
return true;
}
case LookupResult::AmbiguousReference: {
Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
LookupResult::iterator DI = Result.begin(), DE = Result.end();
for (; DI != DE; ++DI)
Diag((*DI)->getLocation(), diag::note_ambiguous_candidate) << *DI;
return true;
}
}
llvm_unreachable("unknown ambiguity kind");
}
namespace {
struct AssociatedLookup {
AssociatedLookup(Sema &S,
Sema::AssociatedNamespaceSet &Namespaces,
Sema::AssociatedClassSet &Classes)
: S(S), Namespaces(Namespaces), Classes(Classes) {
}
Sema &S;
Sema::AssociatedNamespaceSet &Namespaces;
Sema::AssociatedClassSet &Classes;
};
}
static void
addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces,
DeclContext *Ctx) {
// Add the associated namespace for this class.
// We don't use DeclContext::getEnclosingNamespaceContext() as this may
// be a locally scoped record.
// We skip out of inline namespaces. The innermost non-inline namespace
// contains all names of all its nested inline namespaces anyway, so we can
// replace the entire inline namespace tree with its root.
while (Ctx->isRecord() || Ctx->isTransparentContext() ||
Ctx->isInlineNamespace())
Ctx = Ctx->getParent();
if (Ctx->isFileContext())
Namespaces.insert(Ctx->getPrimaryContext());
}
// \brief Add the associated classes and namespaces for argument-dependent
// lookup that involves a template argument (C++ [basic.lookup.koenig]p2).
static void
addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
const TemplateArgument &Arg) {
// C++ [basic.lookup.koenig]p2, last bullet:
// -- [...] ;
switch (Arg.getKind()) {
case TemplateArgument::Null:
break;
case TemplateArgument::Type:
// [...] the namespaces and classes associated with the types of the
// template arguments provided for template type parameters (excluding
// template template parameters)
addAssociatedClassesAndNamespaces(Result, Arg.getAsType());
break;
case TemplateArgument::Template:
case TemplateArgument::TemplateExpansion: {
// [...] the namespaces in which any template template arguments are
// defined; and the classes in which any member templates used as
// template template arguments are defined.
TemplateName Template = Arg.getAsTemplateOrTemplatePattern();
if (ClassTemplateDecl *ClassTemplate
= dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
DeclContext *Ctx = ClassTemplate->getDeclContext();
if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
Result.Classes.insert(EnclosingClass);
// Add the associated namespace for this class.
CollectEnclosingNamespace(Result.Namespaces, Ctx);
}
break;
}
case TemplateArgument::Declaration:
case TemplateArgument::Integral:
case TemplateArgument::Expression:
// [Note: non-type template arguments do not contribute to the set of
// associated namespaces. ]
break;
case TemplateArgument::Pack:
for (TemplateArgument::pack_iterator P = Arg.pack_begin(),
PEnd = Arg.pack_end();
P != PEnd; ++P)
addAssociatedClassesAndNamespaces(Result, *P);
break;
}
}
// \brief Add the associated classes and namespaces for
// argument-dependent lookup with an argument of class type
// (C++ [basic.lookup.koenig]p2).
static void
addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
CXXRecordDecl *Class) {
// Just silently ignore anything whose name is __va_list_tag.
if (Class->getDeclName() == Result.S.VAListTagName)
return;
// C++ [basic.lookup.koenig]p2:
// [...]
// -- If T is a class type (including unions), its associated
// classes are: the class itself; the class of which it is a
// member, if any; and its direct and indirect base
// classes. Its associated namespaces are the namespaces in
// which its associated classes are defined.
// Add the class of which it is a member, if any.
DeclContext *Ctx = Class->getDeclContext();
if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
Result.Classes.insert(EnclosingClass);
// Add the associated namespace for this class.
CollectEnclosingNamespace(Result.Namespaces, Ctx);
// Add the class itself. If we've already seen this class, we don't
// need to visit base classes.
if (!Result.Classes.insert(Class))
return;
// -- If T is a template-id, its associated namespaces and classes are
// the namespace in which the template is defined; for member
// templates, the member template's class; the namespaces and classes
// associated with the types of the template arguments provided for
// template type parameters (excluding template template parameters); the
// namespaces in which any template template arguments are defined; and
// the classes in which any member templates used as template template
// arguments are defined. [Note: non-type template arguments do not
// contribute to the set of associated namespaces. ]
if (ClassTemplateSpecializationDecl *Spec
= dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
Result.Classes.insert(EnclosingClass);
// Add the associated namespace for this class.
CollectEnclosingNamespace(Result.Namespaces, Ctx);
const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]);
}
// Only recurse into base classes for complete types.
if (!Class->hasDefinition()) {
// FIXME: we might need to instantiate templates here
return;
}
// Add direct and indirect base classes along with their associated
// namespaces.
SmallVector<CXXRecordDecl *, 32> Bases;
Bases.push_back(Class);
while (!Bases.empty()) {
// Pop this class off the stack.
Class = Bases.back();
Bases.pop_back();
// Visit the base classes.
for (CXXRecordDecl::base_class_iterator Base = Class->bases_begin(),
BaseEnd = Class->bases_end();
Base != BaseEnd; ++Base) {
const RecordType *BaseType = Base->getType()->getAs<RecordType>();
// In dependent contexts, we do ADL twice, and the first time around,
// the base type might be a dependent TemplateSpecializationType, or a
// TemplateTypeParmType. If that happens, simply ignore it.
// FIXME: If we want to support export, we probably need to add the
// namespace of the template in a TemplateSpecializationType, or even
// the classes and namespaces of known non-dependent arguments.
if (!BaseType)
continue;
CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
if (Result.Classes.insert(BaseDecl)) {
// Find the associated namespace for this base class.
DeclContext *BaseCtx = BaseDecl->getDeclContext();
CollectEnclosingNamespace(Result.Namespaces, BaseCtx);
// Make sure we visit the bases of this base class.
if (BaseDecl->bases_begin() != BaseDecl->bases_end())
Bases.push_back(BaseDecl);
}
}
}
}
// \brief Add the associated classes and namespaces for
// argument-dependent lookup with an argument of type T
// (C++ [basic.lookup.koenig]p2).
static void
addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
// C++ [basic.lookup.koenig]p2:
//
// For each argument type T in the function call, there is a set
// of zero or more associated namespaces and a set of zero or more
// associated classes to be considered. The sets of namespaces and
// classes is determined entirely by the types of the function
// arguments (and the namespace of any template template
// argument). Typedef names and using-declarations used to specify
// the types do not contribute to this set. The sets of namespaces
// and classes are determined in the following way:
SmallVector<const Type *, 16> Queue;
const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
while (true) {
switch (T->getTypeClass()) {
#define TYPE(Class, Base)
#define DEPENDENT_TYPE(Class, Base) case Type::Class:
#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
#define ABSTRACT_TYPE(Class, Base)
#include "clang/AST/TypeNodes.def"
// T is canonical. We can also ignore dependent types because
// we don't need to do ADL at the definition point, but if we
// wanted to implement template export (or if we find some other
// use for associated classes and namespaces...) this would be
// wrong.
break;
// -- If T is a pointer to U or an array of U, its associated
// namespaces and classes are those associated with U.
case Type::Pointer:
T = cast<PointerType>(T)->getPointeeType().getTypePtr();
continue;
case Type::ConstantArray:
case Type::IncompleteArray:
case Type::VariableArray:
T = cast<ArrayType>(T)->getElementType().getTypePtr();
continue;
// -- If T is a fundamental type, its associated sets of
// namespaces and classes are both empty.
case Type::Builtin:
break;
// -- If T is a class type (including unions), its associated
// classes are: the class itself; the class of which it is a
// member, if any; and its direct and indirect base
// classes. Its associated namespaces are the namespaces in
// which its associated classes are defined.
case Type::Record: {
CXXRecordDecl *Class
= cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl());
addAssociatedClassesAndNamespaces(Result, Class);
break;
}
// -- If T is an enumeration type, its associated namespace is
// the namespace in which it is defined. If it is class
// member, its associated class is the member's class; else
// it has no associated class.
case Type::Enum: {
EnumDecl *Enum = cast<EnumType>(T)->getDecl();
DeclContext *Ctx = Enum->getDeclContext();
if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
Result.Classes.insert(EnclosingClass);
// Add the associated namespace for this class.
CollectEnclosingNamespace(Result.Namespaces, Ctx);
break;
}
// -- If T is a function type, its associated namespaces and
// classes are those associated with the function parameter
// types and those associated with the return type.
case Type::FunctionProto: {
const FunctionProtoType *Proto = cast<FunctionProtoType>(T);
for (FunctionProtoType::arg_type_iterator Arg = Proto->arg_type_begin(),
ArgEnd = Proto->arg_type_end();
Arg != ArgEnd; ++Arg)
Queue.push_back(Arg->getTypePtr());
// fallthrough
}
case Type::FunctionNoProto: {
const FunctionType *FnType = cast<FunctionType>(T);
T = FnType->getResultType().getTypePtr();
continue;
}
// -- If T is a pointer to a member function of a class X, its
// associated namespaces and classes are those associated
// with the function parameter types and return type,
// together with those associated with X.
//
// -- If T is a pointer to a data member of class X, its
// associated namespaces and classes are those associated
// with the member type together with those associated with
// X.
case Type::MemberPointer: {
const MemberPointerType *MemberPtr = cast<MemberPointerType>(T);
// Queue up the class type into which this points.
Queue.push_back(MemberPtr->getClass());
// And directly continue with the pointee type.
T = MemberPtr->getPointeeType().getTypePtr();
continue;
}
// As an extension, treat this like a normal pointer.
case Type::BlockPointer:
T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr();
continue;
// References aren't covered by the standard, but that's such an
// obvious defect that we cover them anyway.
case Type::LValueReference:
case Type::RValueReference:
T = cast<ReferenceType>(T)->getPointeeType().getTypePtr();
continue;
// These are fundamental types.
case Type::Vector:
case Type::ExtVector:
case Type::Complex:
break;
// If T is an Objective-C object or interface type, or a pointer to an
// object or interface type, the associated namespace is the global
// namespace.
case Type::ObjCObject:
case Type::ObjCInterface:
case Type::ObjCObjectPointer:
Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl());
break;
// Atomic types are just wrappers; use the associations of the
// contained type.
case Type::Atomic:
T = cast<AtomicType>(T)->getValueType().getTypePtr();
continue;
}
if (Queue.empty()) break;
T = Queue.back();
Queue.pop_back();
}
}
/// \brief Find the associated classes and namespaces for
/// argument-dependent lookup for a call with the given set of
/// arguments.
///
/// This routine computes the sets of associated classes and associated
/// namespaces searched by argument-dependent lookup
/// (C++ [basic.lookup.argdep]) for a given set of arguments.
void
Sema::FindAssociatedClassesAndNamespaces(llvm::ArrayRef<Expr *> Args,
AssociatedNamespaceSet &AssociatedNamespaces,
AssociatedClassSet &AssociatedClasses) {
AssociatedNamespaces.clear();
AssociatedClasses.clear();
AssociatedLookup Result(*this, AssociatedNamespaces, AssociatedClasses);
// C++ [basic.lookup.koenig]p2:
// For each argument type T in the function call, there is a set
// of zero or more associated namespaces and a set of zero or more
// associated classes to be considered. The sets of namespaces and
// classes is determined entirely by the types of the function
// arguments (and the namespace of any template template
// argument).
for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
Expr *Arg = Args[ArgIdx];
if (Arg->getType() != Context.OverloadTy) {
addAssociatedClassesAndNamespaces(Result, Arg->getType());
continue;
}
// [...] In addition, if the argument is the name or address of a
// set of overloaded functions and/or function templates, its
// associated classes and namespaces are the union of those
// associated with each of the members of the set: the namespace
// in which the function or function template is defined and the
// classes and namespaces associated with its (non-dependent)
// parameter types and return type.
Arg = Arg->IgnoreParens();
if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg))
if (unaryOp->getOpcode() == UO_AddrOf)
Arg = unaryOp->getSubExpr();
UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg);
if (!ULE) continue;
for (UnresolvedSetIterator I = ULE->decls_begin(), E = ULE->decls_end();
I != E; ++I) {
// Look through any using declarations to find the underlying function.
NamedDecl *Fn = (*I)->getUnderlyingDecl();
FunctionDecl *FDecl = dyn_cast<FunctionDecl>(Fn);
if (!FDecl)
FDecl = cast<FunctionTemplateDecl>(Fn)->getTemplatedDecl();
// Add the classes and namespaces associated with the parameter
// types and return type of this function.
addAssociatedClassesAndNamespaces(Result, FDecl->getType());
}
}
}
/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
/// an acceptable non-member overloaded operator for a call whose
/// arguments have types T1 (and, if non-empty, T2). This routine
/// implements the check in C++ [over.match.oper]p3b2 concerning
/// enumeration types.
static bool
IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn,
QualType T1, QualType T2,
ASTContext &Context) {
if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
return true;
if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
return true;
const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>();
if (Proto->getNumArgs() < 1)
return false;
if (T1->isEnumeralType()) {
QualType ArgType = Proto->getArgType(0).getNonReferenceType();
if (Context.hasSameUnqualifiedType(T1, ArgType))
return true;
}
if (Proto->getNumArgs() < 2)
return false;
if (!T2.isNull() && T2->isEnumeralType()) {
QualType ArgType = Proto->getArgType(1).getNonReferenceType();
if (Context.hasSameUnqualifiedType(T2, ArgType))
return true;
}
return false;
}
NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
SourceLocation Loc,
LookupNameKind NameKind,
RedeclarationKind Redecl) {
LookupResult R(*this, Name, Loc, NameKind, Redecl);
LookupName(R, S);
return R.getAsSingle<NamedDecl>();
}
/// \brief Find the protocol with the given name, if any.
ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II,
SourceLocation IdLoc,
RedeclarationKind Redecl) {
Decl *D = LookupSingleName(TUScope, II, IdLoc,
LookupObjCProtocolName, Redecl);
return cast_or_null<ObjCProtocolDecl>(D);
}
void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
QualType T1, QualType T2,
UnresolvedSetImpl &Functions) {
// C++ [over.match.oper]p3:
// -- The set of non-member candidates is the result of the
// unqualified lookup of operator@ in the context of the
// expression according to the usual rules for name lookup in
// unqualified function calls (3.4.2) except that all member
// functions are ignored. However, if no operand has a class
// type, only those non-member functions in the lookup set
// that have a first parameter of type T1 or "reference to
// (possibly cv-qualified) T1", when T1 is an enumeration
// type, or (if there is a right operand) a second parameter
// of type T2 or "reference to (possibly cv-qualified) T2",
// when T2 is an enumeration type, are candidate functions.
DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
LookupName(Operators, S);
assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
if (Operators.empty())
return;
for (LookupResult::iterator Op = Operators.begin(), OpEnd = Operators.end();
Op != OpEnd; ++Op) {
NamedDecl *Found = (*Op)->getUnderlyingDecl();
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Found)) {
if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context))
Functions.addDecl(*Op, Op.getAccess()); // FIXME: canonical FD
} else if (FunctionTemplateDecl *FunTmpl
= dyn_cast<FunctionTemplateDecl>(Found)) {
// FIXME: friend operators?
// FIXME: do we need to check IsAcceptableNonMemberOperatorCandidate,
// later?
if (!FunTmpl->getDeclContext()->isRecord())
Functions.addDecl(*Op, Op.getAccess());
}
}
}
Sema::SpecialMemberOverloadResult *Sema::LookupSpecialMember(CXXRecordDecl *RD,
CXXSpecialMember SM,
bool ConstArg,
bool VolatileArg,
bool RValueThis,
bool ConstThis,
bool VolatileThis) {
RD = RD->getDefinition();
assert((RD && !RD->isBeingDefined()) &&
"doing special member lookup into record that isn't fully complete");
if (RValueThis || ConstThis || VolatileThis)
assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) &&
"constructors and destructors always have unqualified lvalue this");
if (ConstArg || VolatileArg)
assert((SM != CXXDefaultConstructor && SM != CXXDestructor) &&
"parameter-less special members can't have qualified arguments");
llvm::FoldingSetNodeID ID;
ID.AddPointer(RD);
ID.AddInteger(SM);
ID.AddInteger(ConstArg);
ID.AddInteger(VolatileArg);
ID.AddInteger(RValueThis);
ID.AddInteger(ConstThis);
ID.AddInteger(VolatileThis);
void *InsertPoint;
SpecialMemberOverloadResult *Result =
SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint);
// This was already cached
if (Result)
return Result;
Result = BumpAlloc.Allocate<SpecialMemberOverloadResult>();
Result = new (Result) SpecialMemberOverloadResult(ID);
SpecialMemberCache.InsertNode(Result, InsertPoint);
if (SM == CXXDestructor) {
if (!RD->hasDeclaredDestructor())
DeclareImplicitDestructor(RD);
CXXDestructorDecl *DD = RD->getDestructor();
assert(DD && "record without a destructor");
Result->setMethod(DD);
Result->setKind(DD->isDeleted() ?
SpecialMemberOverloadResult::NoMemberOrDeleted :
SpecialMemberOverloadResult::Success);
return Result;
}
// Prepare for overload resolution. Here we construct a synthetic argument
// if necessary and make sure that implicit functions are declared.
CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD));
DeclarationName Name;
Expr *Arg = 0;
unsigned NumArgs;
QualType ArgType = CanTy;
ExprValueKind VK = VK_LValue;
if (SM == CXXDefaultConstructor) {
Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
NumArgs = 0;
if (RD->needsImplicitDefaultConstructor())
DeclareImplicitDefaultConstructor(RD);
} else {
if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) {
Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
if (!RD->hasDeclaredCopyConstructor())
DeclareImplicitCopyConstructor(RD);
if (getLangOpts().CPlusPlus0x && RD->needsImplicitMoveConstructor())
DeclareImplicitMoveConstructor(RD);
} else {
Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
if (!RD->hasDeclaredCopyAssignment())
DeclareImplicitCopyAssignment(RD);
if (getLangOpts().CPlusPlus0x && RD->needsImplicitMoveAssignment())
DeclareImplicitMoveAssignment(RD);
}
if (ConstArg)
ArgType.addConst();
if (VolatileArg)
ArgType.addVolatile();
// This isn't /really/ specified by the standard, but it's implied
// we should be working from an RValue in the case of move to ensure
// that we prefer to bind to rvalue references, and an LValue in the
// case of copy to ensure we don't bind to rvalue references.
// Possibly an XValue is actually correct in the case of move, but
// there is no semantic difference for class types in this restricted
// case.
if (SM == CXXCopyConstructor || SM == CXXCopyAssignment)
VK = VK_LValue;
else
VK = VK_RValue;
}
OpaqueValueExpr FakeArg(SourceLocation(), ArgType, VK);
if (SM != CXXDefaultConstructor) {
NumArgs = 1;
Arg = &FakeArg;
}
// Create the object argument
QualType ThisTy = CanTy;
if (ConstThis)
ThisTy.addConst();
if (VolatileThis)
ThisTy.addVolatile();
Expr::Classification Classification =
OpaqueValueExpr(SourceLocation(), ThisTy,
RValueThis ? VK_RValue : VK_LValue).Classify(Context);
// Now we perform lookup on the name we computed earlier and do overload
// resolution. Lookup is only performed directly into the class since there
// will always be a (possibly implicit) declaration to shadow any others.
OverloadCandidateSet OCS((SourceLocation()));
DeclContext::lookup_iterator I, E;
llvm::tie(I, E) = RD->lookup(Name);
assert((I != E) &&
"lookup for a constructor or assignment operator was empty");
for ( ; I != E; ++I) {
Decl *Cand = *I;
if (Cand->isInvalidDecl())
continue;
if (UsingShadowDecl *U = dyn_cast<UsingShadowDecl>(Cand)) {
// FIXME: [namespace.udecl]p15 says that we should only consider a
// using declaration here if it does not match a declaration in the
// derived class. We do not implement this correctly in other cases
// either.
Cand = U->getTargetDecl();
if (Cand->isInvalidDecl())
continue;
}
if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand)) {
if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
AddMethodCandidate(M, DeclAccessPair::make(M, AS_public), RD, ThisTy,
Classification, llvm::makeArrayRef(&Arg, NumArgs),
OCS, true);
else
AddOverloadCandidate(M, DeclAccessPair::make(M, AS_public),
llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
} else if (FunctionTemplateDecl *Tmpl =
dyn_cast<FunctionTemplateDecl>(Cand)) {
if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
AddMethodTemplateCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public),
RD, 0, ThisTy, Classification,
llvm::makeArrayRef(&Arg, NumArgs),
OCS, true);
else
AddTemplateOverloadCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public),
0, llvm::makeArrayRef(&Arg, NumArgs),
OCS, true);
} else {
assert(isa<UsingDecl>(Cand) && "illegal Kind of operator = Decl");
}
}
OverloadCandidateSet::iterator Best;
switch (OCS.BestViableFunction(*this, SourceLocation(), Best)) {
case OR_Success:
Result->setMethod(cast<CXXMethodDecl>(Best->Function));
Result->setKind(SpecialMemberOverloadResult::Success);
break;
case OR_Deleted:
Result->setMethod(cast<CXXMethodDecl>(Best->Function));
Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
break;
case OR_Ambiguous:
Result->setMethod(0);
Result->setKind(SpecialMemberOverloadResult::Ambiguous);
break;
case OR_No_Viable_Function:
Result->setMethod(0);
Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
break;
}
return Result;
}
/// \brief Look up the default constructor for the given class.
CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) {
SpecialMemberOverloadResult *Result =
LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false,
false, false);
return cast_or_null<CXXConstructorDecl>(Result->getMethod());
}
/// \brief Look up the copying constructor for the given class.
CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class,
unsigned Quals) {
assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
"non-const, non-volatile qualifiers for copy ctor arg");
SpecialMemberOverloadResult *Result =
LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const,
Quals & Qualifiers::Volatile, false, false, false);
return cast_or_null<CXXConstructorDecl>(Result->getMethod());
}
/// \brief Look up the moving constructor for the given class.
CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class,
unsigned Quals) {
SpecialMemberOverloadResult *Result =
LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const,
Quals & Qualifiers::Volatile, false, false, false);
return cast_or_null<CXXConstructorDecl>(Result->getMethod());
}
/// \brief Look up the constructors for the given class.
DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) {
// If the implicit constructors have not yet been declared, do so now.
if (CanDeclareSpecialMemberFunction(Context, Class)) {
if (Class->needsImplicitDefaultConstructor())
DeclareImplicitDefaultConstructor(Class);
if (!Class->hasDeclaredCopyConstructor())
DeclareImplicitCopyConstructor(Class);
if (getLangOpts().CPlusPlus0x && Class->needsImplicitMoveConstructor())
DeclareImplicitMoveConstructor(Class);
}
CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class));
DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T);
return Class->lookup(Name);
}
/// \brief Look up the copying assignment operator for the given class.
CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class,
unsigned Quals, bool RValueThis,
unsigned ThisQuals) {
assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
"non-const, non-volatile qualifiers for copy assignment arg");
assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
"non-const, non-volatile qualifiers for copy assignment this");
SpecialMemberOverloadResult *Result =
LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const,
Quals & Qualifiers::Volatile, RValueThis,
ThisQuals & Qualifiers::Const,
ThisQuals & Qualifiers::Volatile);
return Result->getMethod();
}
/// \brief Look up the moving assignment operator for the given class.
CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class,
unsigned Quals,
bool RValueThis,
unsigned ThisQuals) {
assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
"non-const, non-volatile qualifiers for copy assignment this");
SpecialMemberOverloadResult *Result =
LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const,
Quals & Qualifiers::Volatile, RValueThis,
ThisQuals & Qualifiers::Const,
ThisQuals & Qualifiers::Volatile);
return Result->getMethod();
}
/// \brief Look for the destructor of the given class.
///
/// During semantic analysis, this routine should be used in lieu of
/// CXXRecordDecl::getDestructor().
///
/// \returns The destructor for this class.
CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) {
return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor,
false, false, false,
false, false)->getMethod());
}
/// LookupLiteralOperator - Determine which literal operator should be used for
/// a user-defined literal, per C++11 [lex.ext].
///
/// Normal overload resolution is not used to select which literal operator to
/// call for a user-defined literal. Look up the provided literal operator name,
/// and filter the results to the appropriate set for the given argument types.
Sema::LiteralOperatorLookupResult
Sema::LookupLiteralOperator(Scope *S, LookupResult &R,
ArrayRef<QualType> ArgTys,
bool AllowRawAndTemplate) {
LookupName(R, S);
assert(R.getResultKind() != LookupResult::Ambiguous &&
"literal operator lookup can't be ambiguous");
// Filter the lookup results appropriately.
LookupResult::Filter F = R.makeFilter();
bool FoundTemplate = false;
bool FoundRaw = false;
bool FoundExactMatch = false;
while (F.hasNext()) {
Decl *D = F.next();
if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
D = USD->getTargetDecl();
bool IsTemplate = isa<FunctionTemplateDecl>(D);
bool IsRaw = false;
bool IsExactMatch = false;
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
if (FD->getNumParams() == 1 &&
FD->getParamDecl(0)->getType()->getAs<PointerType>())
IsRaw = true;
else {
IsExactMatch = true;
for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
QualType ParamTy = FD->getParamDecl(ArgIdx)->getType();
if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) {
IsExactMatch = false;
break;
}
}
}
}
if (IsExactMatch) {
FoundExactMatch = true;
AllowRawAndTemplate = false;
if (FoundRaw || FoundTemplate) {
// Go through again and remove the raw and template decls we've
// already found.
F.restart();
FoundRaw = FoundTemplate = false;
}
} else if (AllowRawAndTemplate && (IsTemplate || IsRaw)) {
FoundTemplate |= IsTemplate;
FoundRaw |= IsRaw;
} else {
F.erase();
}
}
F.done();
// C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
// parameter type, that is used in preference to a raw literal operator
// or literal operator template.
if (FoundExactMatch)
return LOLR_Cooked;
// C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
// operator template, but not both.
if (FoundRaw && FoundTemplate) {
Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
Decl *D = *I;
if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
D = USD->getTargetDecl();
if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D))
D = FunTmpl->getTemplatedDecl();
NoteOverloadCandidate(cast<FunctionDecl>(D));
}
return LOLR_Error;
}
if (FoundRaw)
return LOLR_Raw;
if (FoundTemplate)
return LOLR_Template;
// Didn't find anything we could use.
Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator)
<< R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
<< (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRawAndTemplate;
return LOLR_Error;
}
void ADLResult