Complete reimplementation of the synthesis for implicitly-defined copy
assignment operators.
Previously, Sema provided type-checking and template instantiation for
copy assignment operators, then CodeGen would synthesize the actual
body of the copy constructor. Unfortunately, the two were not in sync,
and CodeGen might pick a copy-assignment operator that is different
from what Sema chose, leading to strange failures, e.g., link-time
failures when CodeGen called a copy-assignment operator that was not
instantiation, run-time failures when copy-assignment operators were
overloaded for const/non-const references and the wrong one was
picked, and run-time failures when by-value copy-assignment operators
did not have their arguments properly copy-initialized.
This implementation synthesizes the implicitly-defined copy assignment
operator bodies in Sema, so that the resulting ASTs encode exactly
what CodeGen needs to do; there is no longer any special code in
CodeGen to synthesize copy-assignment operators. The synthesis of the
body is relatively simple, and we generate one of three different
kinds of copy statements for each base or member:
- For a class subobject, call the appropriate copy-assignment
operator, after overload resolution has determined what that is.
- For an array of scalar types or an array of class types that have
trivial copy assignment operators, construct a call to
__builtin_memcpy.
- For an array of class types with non-trivial copy assignment
operators, synthesize a (possibly nested!) for loop whose inner
statement calls the copy constructor.
- For a scalar type, use built-in assignment.
This patch fixes at least a few tests cases in Boost.Spirit that were
failing because CodeGen picked the wrong copy-assignment operator
(leading to link-time failures), and I suspect a number of undiagnosed
problems will also go away with this change.
Some of the diagnostics we had previously have gotten worse with this
change, since we're going through generic code for our
type-checking. I will improve this in a subsequent patch.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@102853 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/DeclCXX.cpp b/lib/AST/DeclCXX.cpp
index e6e9ee6..68f4a82 100644
--- a/lib/AST/DeclCXX.cpp
+++ b/lib/AST/DeclCXX.cpp
@@ -633,6 +633,27 @@
return true;
}
+bool CXXMethodDecl::isCopyAssignmentOperator() const {
+ // C++0x [class.copy]p19:
+ // A user-declared copy assignment operator X::operator= is a non-static
+ // non-template member function of class X with exactly one parameter of
+ // type X, X&, const X&, volatile X& or const volatile X&.
+ if (/*operator=*/getOverloadedOperator() != OO_Equal ||
+ /*non-static*/ isStatic() ||
+ /*non-template*/getPrimaryTemplate() || getDescribedFunctionTemplate() ||
+ /*exactly one parameter*/getNumParams() != 1)
+ return false;
+
+ QualType ParamType = getParamDecl(0)->getType();
+ if (const LValueReferenceType *Ref = ParamType->getAs<LValueReferenceType>())
+ ParamType = Ref->getPointeeType();
+
+ ASTContext &Context = getASTContext();
+ QualType ClassType
+ = Context.getCanonicalType(Context.getTypeDeclType(getParent()));
+ return Context.hasSameUnqualifiedType(ClassType, ParamType);
+}
+
void CXXMethodDecl::addOverriddenMethod(const CXXMethodDecl *MD) {
assert(MD->isCanonicalDecl() && "Method is not canonical!");
assert(!MD->getParent()->isDependentContext() &&
diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index dd8eec1..851284e 100644
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -712,98 +712,6 @@
InitializeVTablePointers(ClassDecl);
}
-/// SynthesizeCXXCopyAssignment - Implicitly define copy assignment operator.
-/// Before the implicitly-declared copy assignment operator for a class is
-/// implicitly defined, all implicitly- declared copy assignment operators for
-/// its direct base classes and its nonstatic data members shall have been
-/// implicitly defined. [12.8-p12]
-/// The implicitly-defined copy assignment operator for class X performs
-/// memberwise assignment of its subob- jects. The direct base classes of X are
-/// assigned first, in the order of their declaration in
-/// the base-specifier-list, and then the immediate nonstatic data members of X
-/// are assigned, in the order in which they were declared in the class
-/// definition.Each subobject is assigned in the manner appropriate to its type:
-/// if the subobject is of class type, the copy assignment operator for the
-/// class is used (as if by explicit qualification; that is, ignoring any
-/// possible virtual overriding functions in more derived classes);
-///
-/// if the subobject is an array, each element is assigned, in the manner
-/// appropriate to the element type;
-///
-/// if the subobject is of scalar type, the built-in assignment operator is
-/// used.
-void CodeGenFunction::SynthesizeCXXCopyAssignment(const FunctionArgList &Args) {
- const CXXMethodDecl *MD = cast<CXXMethodDecl>(CurGD.getDecl());
- const CXXRecordDecl *ClassDecl = MD->getParent();
- assert(!ClassDecl->hasUserDeclaredCopyAssignment() &&
- "SynthesizeCXXCopyAssignment - copy assignment has user declaration");
-
- llvm::Value *ThisPtr = LoadCXXThis();
- llvm::Value *SrcPtr =
- Builder.CreateLoad(GetAddrOfLocalVar(Args[1].first));
-
- for (CXXRecordDecl::base_class_const_iterator Base = ClassDecl->bases_begin();
- Base != ClassDecl->bases_end(); ++Base) {
-
- llvm::Value *Dest = GetAddressOfBaseClass(ThisPtr, ClassDecl,
- CXXBaseSpecifierArray(Base),
- /*NullCheckValue=*/false);
- llvm::Value *Src = GetAddressOfBaseClass(SrcPtr, ClassDecl,
- CXXBaseSpecifierArray(Base),
- /*NullCheckValue=*/false);
- CXXRecordDecl *BaseClassDecl
- = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
- EmitClassCopyAssignment(Dest, Src, BaseClassDecl);
- }
-
- for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
- FieldEnd = ClassDecl->field_end();
- Field != FieldEnd; ++Field) {
- QualType FieldType = getContext().getCanonicalType((*Field)->getType());
- const ConstantArrayType *Array =
- getContext().getAsConstantArrayType(FieldType);
- if (Array)
- FieldType = getContext().getBaseElementType(FieldType);
-
- if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) {
- CXXRecordDecl *FieldClassDecl
- = cast<CXXRecordDecl>(FieldClassType->getDecl());
- LValue LHS = EmitLValueForField(ThisPtr, *Field, 0);
- LValue RHS = EmitLValueForField(SrcPtr, *Field, 0);
- if (Array) {
- const llvm::Type *BasePtr = ConvertType(FieldType);
- BasePtr = llvm::PointerType::getUnqual(BasePtr);
- llvm::Value *DestBaseAddrPtr =
- Builder.CreateBitCast(LHS.getAddress(), BasePtr);
- llvm::Value *SrcBaseAddrPtr =
- Builder.CreateBitCast(RHS.getAddress(), BasePtr);
- EmitClassAggrCopyAssignment(DestBaseAddrPtr, SrcBaseAddrPtr, Array,
- FieldClassDecl, FieldType);
- }
- else
- EmitClassCopyAssignment(LHS.getAddress(), RHS.getAddress(),
- FieldClassDecl);
- continue;
- }
- // Do a built-in assignment of scalar data members.
- LValue LHS = EmitLValueForField(ThisPtr, *Field, 0);
- LValue RHS = EmitLValueForField(SrcPtr, *Field, 0);
- if (!hasAggregateLLVMType(Field->getType())) {
- RValue RVRHS = EmitLoadOfLValue(RHS, Field->getType());
- EmitStoreThroughLValue(RVRHS, LHS, Field->getType());
- } else if (Field->getType()->isAnyComplexType()) {
- ComplexPairTy Pair = LoadComplexFromAddr(RHS.getAddress(),
- RHS.isVolatileQualified());
- StoreComplexToAddr(Pair, LHS.getAddress(), LHS.isVolatileQualified());
- } else {
- EmitAggregateCopy(LHS.getAddress(), RHS.getAddress(), Field->getType());
- }
- }
-
- // return *this;
- Builder.CreateStore(ThisPtr, ReturnValue);
-}
-
static void EmitBaseInitializer(CodeGenFunction &CGF,
const CXXRecordDecl *ClassDecl,
CXXBaseOrMemberInitializer *BaseInit,
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index 110a8dc..34b9049 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -246,15 +246,8 @@
void CodeGenFunction::EmitFunctionBody(FunctionArgList &Args) {
const FunctionDecl *FD = cast<FunctionDecl>(CurGD.getDecl());
-
- Stmt *Body = FD->getBody();
- if (Body)
- EmitStmt(Body);
- else {
- assert(FD->isImplicit() && "non-implicit function def has no body");
- assert(FD->isCopyAssignment() && "implicit function not copy assignment");
- SynthesizeCXXCopyAssignment(Args);
- }
+ assert(FD->getBody());
+ EmitStmt(FD->getBody());
}
void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn) {
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 58894ec..7be895d 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -553,7 +553,6 @@
void SynthesizeCXXCopyConstructor(const FunctionArgList &Args);
- void SynthesizeCXXCopyAssignment(const FunctionArgList &Args);
/// EmitDtorEpilogue - Emit all code that comes at the end of class's
/// destructor. This is to call destructors on members and base classes in
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 49b1899..1c82baf 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -1899,7 +1899,8 @@
const CXXScopeSpec &SS,
NamedDecl *FirstQualifierInScope,
LookupResult &R,
- const TemplateArgumentListInfo *TemplateArgs);
+ const TemplateArgumentListInfo *TemplateArgs,
+ bool SuppressQualifierCheck = false);
OwningExprResult LookupMemberExpr(LookupResult &R, Expr *&Base,
bool &IsArrow, SourceLocation OpLoc,
@@ -2186,12 +2187,6 @@
void DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
CXXMethodDecl *MethodDecl);
- /// getAssignOperatorMethod - Returns the default copy assignmment operator
- /// for the class.
- CXXMethodDecl *getAssignOperatorMethod(SourceLocation CurrentLocation,
- ParmVarDecl *Decl,
- CXXRecordDecl *ClassDecl);
-
/// MaybeBindToTemporary - If the passed in expression has a record type with
/// a non-trivial destructor, this will return CXXBindTemporaryExpr. Otherwise
/// it simply returns the passed in expression.
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 6f79a51..e4a154d 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -16,12 +16,13 @@
#include "Lookup.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
-#include "clang/AST/RecordLayout.h"
+#include "clang/AST/CharUnits.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/DeclVisitor.h"
+#include "clang/AST/RecordLayout.h"
+#include "clang/AST/StmtVisitor.h"
#include "clang/AST/TypeLoc.h"
#include "clang/AST/TypeOrdering.h"
-#include "clang/AST/StmtVisitor.h"
#include "clang/Parse/DeclSpec.h"
#include "clang/Parse/Template.h"
#include "clang/Basic/PartialDiagnostic.h"
@@ -2634,7 +2635,7 @@
// Add the parameter to the operator.
ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment,
ClassDecl->getLocation(),
- /*IdentifierInfo=*/0,
+ /*Id=*/0,
ArgType, /*TInfo=*/0,
VarDecl::None,
VarDecl::None, 0);
@@ -4109,102 +4110,423 @@
Destructor->setUsed();
}
-void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
- CXXMethodDecl *MethodDecl) {
- assert((MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() &&
- MethodDecl->getOverloadedOperator() == OO_Equal &&
- !MethodDecl->isUsed()) &&
- "DefineImplicitCopyAssignment called for wrong function");
-
- CXXRecordDecl *ClassDecl
- = cast<CXXRecordDecl>(MethodDecl->getDeclContext());
-
- ImplicitlyDefinedFunctionScope Scope(*this, MethodDecl);
-
- // C++[class.copy] p12
- // Before the implicitly-declared copy assignment operator for a class is
- // implicitly defined, all implicitly-declared copy assignment operators
- // for its direct base classes and its nonstatic data members shall have
- // been implicitly defined.
- bool err = false;
- for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
- E = ClassDecl->bases_end(); Base != E; ++Base) {
- CXXRecordDecl *BaseClassDecl
- = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
- if (CXXMethodDecl *BaseAssignOpMethod =
- getAssignOperatorMethod(CurrentLocation, MethodDecl->getParamDecl(0),
- BaseClassDecl)) {
- CheckDirectMemberAccess(Base->getSourceRange().getBegin(),
- BaseAssignOpMethod,
- PDiag(diag::err_access_assign_base)
- << Base->getType());
-
- MarkDeclarationReferenced(CurrentLocation, BaseAssignOpMethod);
+/// \brief Builds a statement that copies the given entity from \p From to
+/// \c To.
+///
+/// This routine is used to copy the members of a class with an
+/// implicitly-declared copy assignment operator. When the entities being
+/// copied are arrays, this routine builds for loops to copy them.
+///
+/// \param S The Sema object used for type-checking.
+///
+/// \param Loc The location where the implicit copy is being generated.
+///
+/// \param T The type of the expressions being copied. Both expressions must
+/// have this type.
+///
+/// \param To The expression we are copying to.
+///
+/// \param From The expression we are copying from.
+///
+/// \param Depth Internal parameter recording the depth of the recursion.
+///
+/// \returns A statement or a loop that copies the expressions.
+static Sema::OwningStmtResult
+BuildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
+ Sema::OwningExprResult To, Sema::OwningExprResult From,
+ unsigned Depth = 0) {
+ typedef Sema::OwningStmtResult OwningStmtResult;
+ typedef Sema::OwningExprResult OwningExprResult;
+
+ // C++0x [class.copy]p30:
+ // Each subobject is assigned in the manner appropriate to its type:
+ //
+ // - if the subobject is of class type, the copy assignment operator
+ // for the class is used (as if by explicit qualification; that is,
+ // ignoring any possible virtual overriding functions in more derived
+ // classes);
+ if (const RecordType *RecordTy = T->getAs<RecordType>()) {
+ CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
+
+ // Look for operator=.
+ DeclarationName Name
+ = S.Context.DeclarationNames.getCXXOperatorName(OO_Equal);
+ LookupResult OpLookup(S, Name, Loc, Sema::LookupOrdinaryName);
+ S.LookupQualifiedName(OpLookup, ClassDecl, false);
+
+ // Filter out any result that isn't a copy-assignment operator.
+ LookupResult::Filter F = OpLookup.makeFilter();
+ while (F.hasNext()) {
+ NamedDecl *D = F.next();
+ if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
+ if (Method->isCopyAssignmentOperator())
+ continue;
+
+ F.erase();
}
+ F.done();
+
+ // Create the nested-name-specifier that will be used to qualify the
+ // reference to operator=; this is required to suppress the virtual
+ // call mechanism.
+ CXXScopeSpec SS;
+ SS.setRange(Loc);
+ SS.setScopeRep(NestedNameSpecifier::Create(S.Context, 0, false,
+ T.getTypePtr()));
+
+ // Create the reference to operator=.
+ OwningExprResult OpEqualRef
+ = S.BuildMemberReferenceExpr(move(To), T, Loc, /*isArrow=*/false, SS,
+ /*FirstQualifierInScope=*/0, OpLookup,
+ /*TemplateArgs=*/0,
+ /*SuppressQualifierCheck=*/true);
+ if (OpEqualRef.isInvalid())
+ return S.StmtError();
+
+ // Build the call to the assignment operator.
+ Expr *FromE = From.takeAs<Expr>();
+ OwningExprResult Call = S.BuildCallToMemberFunction(/*Scope=*/0,
+ OpEqualRef.takeAs<Expr>(),
+ Loc, &FromE, 1, 0, Loc);
+ if (Call.isInvalid())
+ return S.StmtError();
+
+ return S.Owned(Call.takeAs<Stmt>());
}
- for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
- E = ClassDecl->field_end(); Field != E; ++Field) {
- QualType FieldType = Context.getCanonicalType((*Field)->getType());
- if (const ArrayType *Array = Context.getAsArrayType(FieldType))
- FieldType = Array->getElementType();
- if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) {
- CXXRecordDecl *FieldClassDecl
- = cast<CXXRecordDecl>(FieldClassType->getDecl());
- if (CXXMethodDecl *FieldAssignOpMethod =
- getAssignOperatorMethod(CurrentLocation, MethodDecl->getParamDecl(0),
- FieldClassDecl)) {
- CheckDirectMemberAccess(Field->getLocation(),
- FieldAssignOpMethod,
- PDiag(diag::err_access_assign_field)
- << Field->getDeclName() << Field->getType());
- MarkDeclarationReferenced(CurrentLocation, FieldAssignOpMethod);
- }
- } else if (FieldType->isReferenceType()) {
- Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
- << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
- Diag(Field->getLocation(), diag::note_declared_at);
- Diag(CurrentLocation, diag::note_first_required_here);
- err = true;
- } else if (FieldType.isConstQualified()) {
- Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
- << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
- Diag(Field->getLocation(), diag::note_declared_at);
- Diag(CurrentLocation, diag::note_first_required_here);
- err = true;
- }
+ // - if the subobject is of scalar type, the built-in assignment
+ // operator is used.
+ const ConstantArrayType *ArrayTy = S.Context.getAsConstantArrayType(T);
+ if (!ArrayTy) {
+ OwningExprResult Assignment = S.CreateBuiltinBinOp(Loc,
+ BinaryOperator::Assign,
+ To.takeAs<Expr>(),
+ From.takeAs<Expr>());
+ if (Assignment.isInvalid())
+ return S.StmtError();
+
+ return S.Owned(Assignment.takeAs<Stmt>());
}
- if (!err)
- MethodDecl->setUsed();
+
+ // - if the subobject is an array, each element is assigned, in the
+ // manner appropriate to the element type;
+
+ // Construct a loop over the array bounds, e.g.,
+ //
+ // for (__SIZE_TYPE__ i0 = 0; i0 != array-size; ++i0)
+ //
+ // that will copy each of the array elements.
+ QualType SizeType = S.Context.getSizeType();
+
+ // Create the iteration variable.
+ IdentifierInfo *IterationVarName = 0;
+ {
+ llvm::SmallString<8> Str;
+ llvm::raw_svector_ostream OS(Str);
+ OS << "__i" << Depth;
+ IterationVarName = &S.Context.Idents.get(OS.str());
+ }
+ VarDecl *IterationVar = VarDecl::Create(S.Context, S.CurContext, Loc,
+ IterationVarName, SizeType,
+ S.Context.getTrivialTypeSourceInfo(SizeType, Loc),
+ VarDecl::None, VarDecl::None);
+
+ // Initialize the iteration variable to zero.
+ llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
+ IterationVar->setInit(new (S.Context) IntegerLiteral(Zero, SizeType, Loc));
+
+ // Create a reference to the iteration variable; we'll use this several
+ // times throughout.
+ Expr *IterationVarRef
+ = S.BuildDeclRefExpr(IterationVar, SizeType, Loc).takeAs<Expr>();
+ assert(IterationVarRef && "Reference to invented variable cannot fail!");
+
+ // Create the DeclStmt that holds the iteration variable.
+ Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(IterationVar),Loc,Loc);
+
+ // Create the comparison against the array bound.
+ llvm::APInt Upper = ArrayTy->getSize();
+ Upper.zextOrTrunc(S.Context.getTypeSize(SizeType));
+ OwningExprResult Comparison
+ = S.Owned(new (S.Context) BinaryOperator(IterationVarRef->Retain(),
+ new (S.Context) IntegerLiteral(Upper, SizeType, Loc),
+ BinaryOperator::NE, S.Context.BoolTy, Loc));
+
+ // Create the pre-increment of the iteration variable.
+ OwningExprResult Increment
+ = S.Owned(new (S.Context) UnaryOperator(IterationVarRef->Retain(),
+ UnaryOperator::PreInc,
+ SizeType, Loc));
+
+ // Subscript the "from" and "to" expressions with the iteration variable.
+ From = S.CreateBuiltinArraySubscriptExpr(move(From), Loc,
+ S.Owned(IterationVarRef->Retain()),
+ Loc);
+ To = S.CreateBuiltinArraySubscriptExpr(move(To), Loc,
+ S.Owned(IterationVarRef->Retain()),
+ Loc);
+ assert(!From.isInvalid() && "Builtin subscripting can't fail!");
+ assert(!To.isInvalid() && "Builtin subscripting can't fail!");
+
+ // Build the copy for an individual element of the array.
+ OwningStmtResult Copy = BuildSingleCopyAssign(S, Loc,
+ ArrayTy->getElementType(),
+ move(To), move(From), Depth+1);
+ if (Copy.isInvalid()) {
+ InitStmt->Destroy(S.Context);
+ return S.StmtError();
+ }
+
+ // Construct the loop that copies all elements of this array.
+ return S.ActOnForStmt(Loc, Loc, S.Owned(InitStmt),
+ S.MakeFullExpr(Comparison),
+ Sema::DeclPtrTy(),
+ S.MakeFullExpr(Increment),
+ Loc, move(Copy));
}
-CXXMethodDecl *
-Sema::getAssignOperatorMethod(SourceLocation CurrentLocation,
- ParmVarDecl *ParmDecl,
- CXXRecordDecl *ClassDecl) {
- QualType LHSType = Context.getTypeDeclType(ClassDecl);
- QualType RHSType(LHSType);
- // If class's assignment operator argument is const/volatile qualified,
- // look for operator = (const/volatile B&). Otherwise, look for
- // operator = (B&).
- RHSType = Context.getCVRQualifiedType(RHSType,
- ParmDecl->getType().getCVRQualifiers());
- ExprOwningPtr<Expr> LHS(this, new (Context) DeclRefExpr(ParmDecl,
- LHSType,
- SourceLocation()));
- ExprOwningPtr<Expr> RHS(this, new (Context) DeclRefExpr(ParmDecl,
- RHSType,
- CurrentLocation));
- Expr *Args[2] = { &*LHS, &*RHS };
- OverloadCandidateSet CandidateSet(CurrentLocation);
- AddMemberOperatorCandidates(clang::OO_Equal, SourceLocation(), Args, 2,
- CandidateSet);
- OverloadCandidateSet::iterator Best;
- if (BestViableFunction(CandidateSet, CurrentLocation, Best) == OR_Success)
- return cast<CXXMethodDecl>(Best->Function);
- assert(false &&
- "getAssignOperatorMethod - copy assignment operator method not found");
- return 0;
+void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
+ CXXMethodDecl *CopyAssignOperator) {
+ assert((CopyAssignOperator->isImplicit() &&
+ CopyAssignOperator->isOverloadedOperator() &&
+ CopyAssignOperator->getOverloadedOperator() == OO_Equal &&
+ !CopyAssignOperator->isUsed()) &&
+ "DefineImplicitCopyAssignment called for wrong function");
+
+ CXXRecordDecl *ClassDecl = CopyAssignOperator->getParent();
+
+ if (ClassDecl->isInvalidDecl() || CopyAssignOperator->isInvalidDecl()) {
+ CopyAssignOperator->setInvalidDecl();
+ return;
+ }
+
+ CopyAssignOperator->setUsed();
+
+ ImplicitlyDefinedFunctionScope Scope(*this, CopyAssignOperator);
+
+ // C++0x [class.copy]p30:
+ // The implicitly-defined or explicitly-defaulted copy assignment operator
+ // for a non-union class X performs memberwise copy assignment of its
+ // subobjects. The direct base classes of X are assigned first, in the
+ // order of their declaration in the base-specifier-list, and then the
+ // immediate non-static data members of X are assigned, in the order in
+ // which they were declared in the class definition.
+
+ // The statements that form the synthesized function body.
+ ASTOwningVector<&ActionBase::DeleteStmt> Statements(*this);
+
+ // The parameter for the "other" object, which we are copying from.
+ ParmVarDecl *Other = CopyAssignOperator->getParamDecl(0);
+ Qualifiers OtherQuals = Other->getType().getQualifiers();
+ QualType OtherRefType = Other->getType();
+ if (const LValueReferenceType *OtherRef
+ = OtherRefType->getAs<LValueReferenceType>()) {
+ OtherRefType = OtherRef->getPointeeType();
+ OtherQuals = OtherRefType.getQualifiers();
+ }
+
+ // Our location for everything implicitly-generated.
+ SourceLocation Loc = CopyAssignOperator->getLocation();
+
+ // Construct a reference to the "other" object. We'll be using this
+ // throughout the generated ASTs.
+ Expr *OtherRef = BuildDeclRefExpr(Other, OtherRefType, Loc).takeAs<Expr>();
+ assert(OtherRef && "Reference to parameter cannot fail!");
+
+ // Construct the "this" pointer. We'll be using this throughout the generated
+ // ASTs.
+ Expr *This = ActOnCXXThis(Loc).takeAs<Expr>();
+ assert(This && "Reference to this cannot fail!");
+
+ // Assign base classes.
+ bool Invalid = false;
+ for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
+ E = ClassDecl->bases_end(); Base != E; ++Base) {
+ // Form the assignment:
+ // static_cast<Base*>(this)->Base::operator=(static_cast<Base&>(other));
+ QualType BaseType = Base->getType().getUnqualifiedType();
+ CXXRecordDecl *BaseClassDecl = 0;
+ if (const RecordType *BaseRecordT = BaseType->getAs<RecordType>())
+ BaseClassDecl = cast<CXXRecordDecl>(BaseRecordT->getDecl());
+ else {
+ Invalid = true;
+ continue;
+ }
+
+ // Construct the "from" expression, which is an implicit cast to the
+ // appropriately-qualified base type.
+ Expr *From = OtherRef->Retain();
+ ImpCastExprToType(From, Context.getQualifiedType(BaseType, OtherQuals),
+ CastExpr::CK_UncheckedDerivedToBase, /*isLvalue=*/true,
+ CXXBaseSpecifierArray(Base));
+
+ // Dereference "this".
+ OwningExprResult To = CreateBuiltinUnaryOp(Loc, UnaryOperator::Deref,
+ Owned(This->Retain()));
+
+ // Implicitly cast "this" to the appropriately-qualified base type.
+ Expr *ToE = To.takeAs<Expr>();
+ ImpCastExprToType(ToE,
+ Context.getCVRQualifiedType(BaseType,
+ CopyAssignOperator->getTypeQualifiers()),
+ CastExpr::CK_UncheckedDerivedToBase,
+ /*isLvalue=*/true, CXXBaseSpecifierArray(Base));
+ To = Owned(ToE);
+
+ // Build the copy.
+ OwningStmtResult Copy = BuildSingleCopyAssign(*this, Loc, BaseType,
+ move(To), Owned(From));
+ if (Copy.isInvalid()) {
+ Invalid = true;
+ continue;
+ }
+
+ // Success! Record the copy.
+ Statements.push_back(Copy.takeAs<Expr>());
+ }
+
+ // \brief Reference to the __builtin_memcpy function.
+ Expr *BuiltinMemCpyRef = 0;
+
+ // Assign non-static members.
+ for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
+ FieldEnd = ClassDecl->field_end();
+ Field != FieldEnd; ++Field) {
+ // Check for members of reference type; we can't copy those.
+ if (Field->getType()->isReferenceType()) {
+ Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
+ << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
+ Diag(Field->getLocation(), diag::note_declared_at);
+ Diag(Loc, diag::note_first_required_here);
+ Invalid = true;
+ continue;
+ }
+
+ // Check for members of const-qualified, non-class type.
+ QualType BaseType = Context.getBaseElementType(Field->getType());
+ if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
+ Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
+ << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
+ Diag(Field->getLocation(), diag::note_declared_at);
+ Diag(Loc, diag::note_first_required_here);
+ Invalid = true;
+ continue;
+ }
+
+ QualType FieldType = Field->getType().getNonReferenceType();
+
+ // Build references to the field in the object we're copying from and to.
+ CXXScopeSpec SS; // Intentionally empty
+ LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
+ LookupMemberName);
+ MemberLookup.addDecl(*Field);
+ MemberLookup.resolveKind();
+ OwningExprResult From = BuildMemberReferenceExpr(Owned(OtherRef->Retain()),
+ OtherRefType,
+ Loc, /*IsArrow=*/false,
+ SS, 0, MemberLookup, 0);
+ OwningExprResult To = BuildMemberReferenceExpr(Owned(This->Retain()),
+ This->getType(),
+ Loc, /*IsArrow=*/true,
+ SS, 0, MemberLookup, 0);
+ assert(!From.isInvalid() && "Implicit field reference cannot fail");
+ assert(!To.isInvalid() && "Implicit field reference cannot fail");
+
+ // If the field should be copied with __builtin_memcpy rather than via
+ // explicit assignments, do so. This optimization only applies for arrays
+ // of scalars and arrays of class type with trivial copy-assignment
+ // operators.
+ if (FieldType->isArrayType() &&
+ (!BaseType->isRecordType() ||
+ cast<CXXRecordDecl>(BaseType->getAs<RecordType>()->getDecl())
+ ->hasTrivialCopyAssignment())) {
+ // Compute the size of the memory buffer to be copied.
+ QualType SizeType = Context.getSizeType();
+ llvm::APInt Size(Context.getTypeSize(SizeType),
+ Context.getTypeSizeInChars(BaseType).getQuantity());
+ for (const ConstantArrayType *Array
+ = Context.getAsConstantArrayType(FieldType);
+ Array;
+ Array = Context.getAsConstantArrayType(Array->getElementType())) {
+ llvm::APInt ArraySize = Array->getSize();
+ ArraySize.zextOrTrunc(Size.getBitWidth());
+ Size *= ArraySize;
+ }
+
+ // Take the address of the field references for "from" and "to".
+ From = CreateBuiltinUnaryOp(Loc, UnaryOperator::AddrOf, move(From));
+ To = CreateBuiltinUnaryOp(Loc, UnaryOperator::AddrOf, move(To));
+
+ // Create a reference to the __builtin_memcpy builtin function.
+ if (!BuiltinMemCpyRef) {
+ LookupResult R(*this, &Context.Idents.get("__builtin_memcpy"), Loc,
+ LookupOrdinaryName);
+ LookupName(R, TUScope, true);
+
+ FunctionDecl *BuiltinMemCpy = R.getAsSingle<FunctionDecl>();
+ if (!BuiltinMemCpy) {
+ // Something went horribly wrong earlier, and we will have complained
+ // about it.
+ Invalid = true;
+ continue;
+ }
+
+ BuiltinMemCpyRef = BuildDeclRefExpr(BuiltinMemCpy,
+ BuiltinMemCpy->getType(),
+ Loc, 0).takeAs<Expr>();
+ assert(BuiltinMemCpyRef && "Builtin reference cannot fail");
+ }
+
+ ASTOwningVector<&ActionBase::DeleteExpr> CallArgs(*this);
+ CallArgs.push_back(To.takeAs<Expr>());
+ CallArgs.push_back(From.takeAs<Expr>());
+ CallArgs.push_back(new (Context) IntegerLiteral(Size, SizeType, Loc));
+ llvm::SmallVector<SourceLocation, 4> Commas; // FIXME: Silly
+ Commas.push_back(Loc);
+ Commas.push_back(Loc);
+ OwningExprResult Call = ActOnCallExpr(/*Scope=*/0,
+ Owned(BuiltinMemCpyRef->Retain()),
+ Loc, move_arg(CallArgs),
+ Commas.data(), Loc);
+ assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!");
+ Statements.push_back(Call.takeAs<Expr>());
+ continue;
+ }
+
+ // Build the copy of this field.
+ OwningStmtResult Copy = BuildSingleCopyAssign(*this, Loc, FieldType,
+ move(To), move(From));
+ if (Copy.isInvalid()) {
+ Invalid = true;
+ continue;
+ }
+
+ // Success! Record the copy.
+ Statements.push_back(Copy.takeAs<Stmt>());
+ }
+
+ if (!Invalid) {
+ // Add a "return *this;"
+ OwningExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UnaryOperator::Deref,
+ Owned(This->Retain()));
+
+ OwningStmtResult Return = ActOnReturnStmt(Loc, move(ThisObj));
+ if (Return.isInvalid())
+ Invalid = true;
+ else {
+ Statements.push_back(Return.takeAs<Stmt>());
+ }
+ }
+
+ if (Invalid) {
+ CopyAssignOperator->setInvalidDecl();
+ return;
+ }
+
+ OwningStmtResult Body = ActOnCompoundStmt(Loc, Loc, move_arg(Statements),
+ /*isStmtExpr=*/false);
+ assert(!Body.isInvalid() && "Compound statement creation cannot fail");
+ CopyAssignOperator->setBody(Body.takeAs<Stmt>());
}
void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 10d470a..c4ab03f 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -2678,7 +2678,8 @@
const CXXScopeSpec &SS,
NamedDecl *FirstQualifierInScope,
LookupResult &R,
- const TemplateArgumentListInfo *TemplateArgs) {
+ const TemplateArgumentListInfo *TemplateArgs,
+ bool SuppressQualifierCheck) {
Expr *BaseExpr = Base.takeAs<Expr>();
QualType BaseType = BaseExprType;
if (IsArrow) {
@@ -2717,6 +2718,7 @@
if ((SS.isSet() || !BaseExpr ||
(isa<CXXThisExpr>(BaseExpr) &&
cast<CXXThisExpr>(BaseExpr)->isImplicit())) &&
+ !SuppressQualifierCheck &&
CheckQualifiedMemberReference(BaseExpr, BaseType, SS, R))
return ExprError();