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//===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements semantic analysis for C++ declarations.
//
//===----------------------------------------------------------------------===//
#include "clang/Sema/SemaInternal.h"
#include "clang/Sema/CXXFieldCollector.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/ScopeInfo.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTMutationListener.h"
#include "clang/AST/CharUnits.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/DeclVisitor.h"
#include "clang/AST/EvaluatedExprVisitor.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/AST/TypeLoc.h"
#include "clang/AST/TypeOrdering.h"
#include "clang/Sema/DeclSpec.h"
#include "clang/Sema/ParsedTemplate.h"
#include "clang/Basic/PartialDiagnostic.h"
#include "clang/Lex/Preprocessor.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/STLExtras.h"
#include <map>
#include <set>
using namespace clang;
//===----------------------------------------------------------------------===//
// CheckDefaultArgumentVisitor
//===----------------------------------------------------------------------===//
namespace {
/// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
/// the default argument of a parameter to determine whether it
/// contains any ill-formed subexpressions. For example, this will
/// diagnose the use of local variables or parameters within the
/// default argument expression.
class CheckDefaultArgumentVisitor
: public StmtVisitor<CheckDefaultArgumentVisitor, bool> {
Expr *DefaultArg;
Sema *S;
public:
CheckDefaultArgumentVisitor(Expr *defarg, Sema *s)
: DefaultArg(defarg), S(s) {}
bool VisitExpr(Expr *Node);
bool VisitDeclRefExpr(DeclRefExpr *DRE);
bool VisitCXXThisExpr(CXXThisExpr *ThisE);
bool VisitLambdaExpr(LambdaExpr *Lambda);
};
/// VisitExpr - Visit all of the children of this expression.
bool CheckDefaultArgumentVisitor::VisitExpr(Expr *Node) {
bool IsInvalid = false;
for (Stmt::child_range I = Node->children(); I; ++I)
IsInvalid |= Visit(*I);
return IsInvalid;
}
/// VisitDeclRefExpr - Visit a reference to a declaration, to
/// determine whether this declaration can be used in the default
/// argument expression.
bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) {
NamedDecl *Decl = DRE->getDecl();
if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) {
// C++ [dcl.fct.default]p9
// Default arguments are evaluated each time the function is
// called. The order of evaluation of function arguments is
// unspecified. Consequently, parameters of a function shall not
// be used in default argument expressions, even if they are not
// evaluated. Parameters of a function declared before a default
// argument expression are in scope and can hide namespace and
// class member names.
return S->Diag(DRE->getLocStart(),
diag::err_param_default_argument_references_param)
<< Param->getDeclName() << DefaultArg->getSourceRange();
} else if (VarDecl *VDecl = dyn_cast<VarDecl>(Decl)) {
// C++ [dcl.fct.default]p7
// Local variables shall not be used in default argument
// expressions.
if (VDecl->isLocalVarDecl())
return S->Diag(DRE->getLocStart(),
diag::err_param_default_argument_references_local)
<< VDecl->getDeclName() << DefaultArg->getSourceRange();
}
return false;
}
/// VisitCXXThisExpr - Visit a C++ "this" expression.
bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(CXXThisExpr *ThisE) {
// C++ [dcl.fct.default]p8:
// The keyword this shall not be used in a default argument of a
// member function.
return S->Diag(ThisE->getLocStart(),
diag::err_param_default_argument_references_this)
<< ThisE->getSourceRange();
}
bool CheckDefaultArgumentVisitor::VisitLambdaExpr(LambdaExpr *Lambda) {
// C++11 [expr.lambda.prim]p13:
// A lambda-expression appearing in a default argument shall not
// implicitly or explicitly capture any entity.
if (Lambda->capture_begin() == Lambda->capture_end())
return false;
return S->Diag(Lambda->getLocStart(),
diag::err_lambda_capture_default_arg);
}
}
void Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc,
CXXMethodDecl *Method) {
// If we have an MSAny spec already, don't bother.
if (!Method || ComputedEST == EST_MSAny)
return;
const FunctionProtoType *Proto
= Method->getType()->getAs<FunctionProtoType>();
Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
if (!Proto)
return;
ExceptionSpecificationType EST = Proto->getExceptionSpecType();
// If this function can throw any exceptions, make a note of that.
if (EST == EST_MSAny || EST == EST_None) {
ClearExceptions();
ComputedEST = EST;
return;
}
// FIXME: If the call to this decl is using any of its default arguments, we
// need to search them for potentially-throwing calls.
// If this function has a basic noexcept, it doesn't affect the outcome.
if (EST == EST_BasicNoexcept)
return;
// If we have a throw-all spec at this point, ignore the function.
if (ComputedEST == EST_None)
return;
// If we're still at noexcept(true) and there's a nothrow() callee,
// change to that specification.
if (EST == EST_DynamicNone) {
if (ComputedEST == EST_BasicNoexcept)
ComputedEST = EST_DynamicNone;
return;
}
// Check out noexcept specs.
if (EST == EST_ComputedNoexcept) {
FunctionProtoType::NoexceptResult NR =
Proto->getNoexceptSpec(Self->Context);
assert(NR != FunctionProtoType::NR_NoNoexcept &&
"Must have noexcept result for EST_ComputedNoexcept.");
assert(NR != FunctionProtoType::NR_Dependent &&
"Should not generate implicit declarations for dependent cases, "
"and don't know how to handle them anyway.");
// noexcept(false) -> no spec on the new function
if (NR == FunctionProtoType::NR_Throw) {
ClearExceptions();
ComputedEST = EST_None;
}
// noexcept(true) won't change anything either.
return;
}
assert(EST == EST_Dynamic && "EST case not considered earlier.");
assert(ComputedEST != EST_None &&
"Shouldn't collect exceptions when throw-all is guaranteed.");
ComputedEST = EST_Dynamic;
// Record the exceptions in this function's exception specification.
for (FunctionProtoType::exception_iterator E = Proto->exception_begin(),
EEnd = Proto->exception_end();
E != EEnd; ++E)
if (ExceptionsSeen.insert(Self->Context.getCanonicalType(*E)))
Exceptions.push_back(*E);
}
void Sema::ImplicitExceptionSpecification::CalledExpr(Expr *E) {
if (!E || ComputedEST == EST_MSAny)
return;
// FIXME:
//
// C++0x [except.spec]p14:
// [An] implicit exception-specification specifies the type-id T if and
// only if T is allowed by the exception-specification of a function directly
// invoked by f's implicit definition; f shall allow all exceptions if any
// function it directly invokes allows all exceptions, and f shall allow no
// exceptions if every function it directly invokes allows no exceptions.
//
// Note in particular that if an implicit exception-specification is generated
// for a function containing a throw-expression, that specification can still
// be noexcept(true).
//
// Note also that 'directly invoked' is not defined in the standard, and there
// is no indication that we should only consider potentially-evaluated calls.
//
// Ultimately we should implement the intent of the standard: the exception
// specification should be the set of exceptions which can be thrown by the
// implicit definition. For now, we assume that any non-nothrow expression can
// throw any exception.
if (Self->canThrow(E))
ComputedEST = EST_None;
}
bool
Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
SourceLocation EqualLoc) {
if (RequireCompleteType(Param->getLocation(), Param->getType(),
diag::err_typecheck_decl_incomplete_type)) {
Param->setInvalidDecl();
return true;
}
// C++ [dcl.fct.default]p5
// A default argument expression is implicitly converted (clause
// 4) to the parameter type. The default argument expression has
// the same semantic constraints as the initializer expression in
// a declaration of a variable of the parameter type, using the
// copy-initialization semantics (8.5).
InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
Param);
InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
EqualLoc);
InitializationSequence InitSeq(*this, Entity, Kind, &Arg, 1);
ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg);
if (Result.isInvalid())
return true;
Arg = Result.takeAs<Expr>();
CheckImplicitConversions(Arg, EqualLoc);
Arg = MaybeCreateExprWithCleanups(Arg);
// Okay: add the default argument to the parameter
Param->setDefaultArg(Arg);
// We have already instantiated this parameter; provide each of the
// instantiations with the uninstantiated default argument.
UnparsedDefaultArgInstantiationsMap::iterator InstPos
= UnparsedDefaultArgInstantiations.find(Param);
if (InstPos != UnparsedDefaultArgInstantiations.end()) {
for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
// We're done tracking this parameter's instantiations.
UnparsedDefaultArgInstantiations.erase(InstPos);
}
return false;
}
/// ActOnParamDefaultArgument - Check whether the default argument
/// provided for a function parameter is well-formed. If so, attach it
/// to the parameter declaration.
void
Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc,
Expr *DefaultArg) {
if (!param || !DefaultArg)
return;
ParmVarDecl *Param = cast<ParmVarDecl>(param);
UnparsedDefaultArgLocs.erase(Param);
// Default arguments are only permitted in C++
if (!getLangOpts().CPlusPlus) {
Diag(EqualLoc, diag::err_param_default_argument)
<< DefaultArg->getSourceRange();
Param->setInvalidDecl();
return;
}
// Check for unexpanded parameter packs.
if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
Param->setInvalidDecl();
return;
}
// Check that the default argument is well-formed
CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg, this);
if (DefaultArgChecker.Visit(DefaultArg)) {
Param->setInvalidDecl();
return;
}
SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
}
/// ActOnParamUnparsedDefaultArgument - We've seen a default
/// argument for a function parameter, but we can't parse it yet
/// because we're inside a class definition. Note that this default
/// argument will be parsed later.
void Sema::ActOnParamUnparsedDefaultArgument(Decl *param,
SourceLocation EqualLoc,
SourceLocation ArgLoc) {
if (!param)
return;
ParmVarDecl *Param = cast<ParmVarDecl>(param);
if (Param)
Param->setUnparsedDefaultArg();
UnparsedDefaultArgLocs[Param] = ArgLoc;
}
/// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
/// the default argument for the parameter param failed.
void Sema::ActOnParamDefaultArgumentError(Decl *param) {
if (!param)
return;
ParmVarDecl *Param = cast<ParmVarDecl>(param);
Param->setInvalidDecl();
UnparsedDefaultArgLocs.erase(Param);
}
/// CheckExtraCXXDefaultArguments - Check for any extra default
/// arguments in the declarator, which is not a function declaration
/// or definition and therefore is not permitted to have default
/// arguments. This routine should be invoked for every declarator
/// that is not a function declaration or definition.
void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
// C++ [dcl.fct.default]p3
// A default argument expression shall be specified only in the
// parameter-declaration-clause of a function declaration or in a
// template-parameter (14.1). It shall not be specified for a
// parameter pack. If it is specified in a
// parameter-declaration-clause, it shall not occur within a
// declarator or abstract-declarator of a parameter-declaration.
for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
DeclaratorChunk &chunk = D.getTypeObject(i);
if (chunk.Kind == DeclaratorChunk::Function) {
for (unsigned argIdx = 0, e = chunk.Fun.NumArgs; argIdx != e; ++argIdx) {
ParmVarDecl *Param =
cast<ParmVarDecl>(chunk.Fun.ArgInfo[argIdx].Param);
if (Param->hasUnparsedDefaultArg()) {
CachedTokens *Toks = chunk.Fun.ArgInfo[argIdx].DefaultArgTokens;
Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
<< SourceRange((*Toks)[1].getLocation(), Toks->back().getLocation());
delete Toks;
chunk.Fun.ArgInfo[argIdx].DefaultArgTokens = 0;
} else if (Param->getDefaultArg()) {
Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
<< Param->getDefaultArg()->getSourceRange();
Param->setDefaultArg(0);
}
}
}
}
}
// MergeCXXFunctionDecl - Merge two declarations of the same C++
// function, once we already know that they have the same
// type. Subroutine of MergeFunctionDecl. Returns true if there was an
// error, false otherwise.
bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old,
Scope *S) {
bool Invalid = false;
// C++ [dcl.fct.default]p4:
// For non-template functions, default arguments can be added in
// later declarations of a function in the same
// scope. Declarations in different scopes have completely
// distinct sets of default arguments. That is, declarations in
// inner scopes do not acquire default arguments from
// declarations in outer scopes, and vice versa. In a given
// function declaration, all parameters subsequent to a
// parameter with a default argument shall have default
// arguments supplied in this or previous declarations. A
// default argument shall not be redefined by a later
// declaration (not even to the same value).
//
// C++ [dcl.fct.default]p6:
// Except for member functions of class templates, the default arguments
// in a member function definition that appears outside of the class
// definition are added to the set of default arguments provided by the
// member function declaration in the class definition.
for (unsigned p = 0, NumParams = Old->getNumParams(); p < NumParams; ++p) {
ParmVarDecl *OldParam = Old->getParamDecl(p);
ParmVarDecl *NewParam = New->getParamDecl(p);
bool OldParamHasDfl = OldParam->hasDefaultArg();
bool NewParamHasDfl = NewParam->hasDefaultArg();
NamedDecl *ND = Old;
if (S && !isDeclInScope(ND, New->getDeclContext(), S))
// Ignore default parameters of old decl if they are not in
// the same scope.
OldParamHasDfl = false;
if (OldParamHasDfl && NewParamHasDfl) {
unsigned DiagDefaultParamID =
diag::err_param_default_argument_redefinition;
// MSVC accepts that default parameters be redefined for member functions
// of template class. The new default parameter's value is ignored.
Invalid = true;
if (getLangOpts().MicrosoftExt) {
CXXMethodDecl* MD = dyn_cast<CXXMethodDecl>(New);
if (MD && MD->getParent()->getDescribedClassTemplate()) {
// Merge the old default argument into the new parameter.
NewParam->setHasInheritedDefaultArg();
if (OldParam->hasUninstantiatedDefaultArg())
NewParam->setUninstantiatedDefaultArg(
OldParam->getUninstantiatedDefaultArg());
else
NewParam->setDefaultArg(OldParam->getInit());
DiagDefaultParamID = diag::warn_param_default_argument_redefinition;
Invalid = false;
}
}
// FIXME: If we knew where the '=' was, we could easily provide a fix-it
// hint here. Alternatively, we could walk the type-source information
// for NewParam to find the last source location in the type... but it
// isn't worth the effort right now. This is the kind of test case that
// is hard to get right:
// int f(int);
// void g(int (*fp)(int) = f);
// void g(int (*fp)(int) = &f);
Diag(NewParam->getLocation(), DiagDefaultParamID)
<< NewParam->getDefaultArgRange();
// Look for the function declaration where the default argument was
// actually written, which may be a declaration prior to Old.
for (FunctionDecl *Older = Old->getPreviousDecl();
Older; Older = Older->getPreviousDecl()) {
if (!Older->getParamDecl(p)->hasDefaultArg())
break;
OldParam = Older->getParamDecl(p);
}
Diag(OldParam->getLocation(), diag::note_previous_definition)
<< OldParam->getDefaultArgRange();
} else if (OldParamHasDfl) {
// Merge the old default argument into the new parameter.
// It's important to use getInit() here; getDefaultArg()
// strips off any top-level ExprWithCleanups.
NewParam->setHasInheritedDefaultArg();
if (OldParam->hasUninstantiatedDefaultArg())
NewParam->setUninstantiatedDefaultArg(
OldParam->getUninstantiatedDefaultArg());
else
NewParam->setDefaultArg(OldParam->getInit());
} else if (NewParamHasDfl) {
if (New->getDescribedFunctionTemplate()) {
// Paragraph 4, quoted above, only applies to non-template functions.
Diag(NewParam->getLocation(),
diag::err_param_default_argument_template_redecl)
<< NewParam->getDefaultArgRange();
Diag(Old->getLocation(), diag::note_template_prev_declaration)
<< false;
} else if (New->getTemplateSpecializationKind()
!= TSK_ImplicitInstantiation &&
New->getTemplateSpecializationKind() != TSK_Undeclared) {
// C++ [temp.expr.spec]p21:
// Default function arguments shall not be specified in a declaration
// or a definition for one of the following explicit specializations:
// - the explicit specialization of a function template;
// - the explicit specialization of a member function template;
// - the explicit specialization of a member function of a class
// template where the class template specialization to which the
// member function specialization belongs is implicitly
// instantiated.
Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
<< (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
<< New->getDeclName()
<< NewParam->getDefaultArgRange();
} else if (New->getDeclContext()->isDependentContext()) {
// C++ [dcl.fct.default]p6 (DR217):
// Default arguments for a member function of a class template shall
// be specified on the initial declaration of the member function
// within the class template.
//
// Reading the tea leaves a bit in DR217 and its reference to DR205
// leads me to the conclusion that one cannot add default function
// arguments for an out-of-line definition of a member function of a
// dependent type.
int WhichKind = 2;
if (CXXRecordDecl *Record
= dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
if (Record->getDescribedClassTemplate())
WhichKind = 0;
else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
WhichKind = 1;
else
WhichKind = 2;
}
Diag(NewParam->getLocation(),
diag::err_param_default_argument_member_template_redecl)
<< WhichKind
<< NewParam->getDefaultArgRange();
} else if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(New)) {
CXXSpecialMember NewSM = getSpecialMember(Ctor),
OldSM = getSpecialMember(cast<CXXConstructorDecl>(Old));
if (NewSM != OldSM) {
Diag(NewParam->getLocation(),diag::warn_default_arg_makes_ctor_special)
<< NewParam->getDefaultArgRange() << NewSM;
Diag(Old->getLocation(), diag::note_previous_declaration_special)
<< OldSM;
}
}
}
}
// C++11 [dcl.constexpr]p1: If any declaration of a function or function
// template has a constexpr specifier then all its declarations shall
// contain the constexpr specifier.
if (New->isConstexpr() != Old->isConstexpr()) {
Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
<< New << New->isConstexpr();
Diag(Old->getLocation(), diag::note_previous_declaration);
Invalid = true;
}
if (CheckEquivalentExceptionSpec(Old, New))
Invalid = true;
return Invalid;
}
/// \brief Merge the exception specifications of two variable declarations.
///
/// This is called when there's a redeclaration of a VarDecl. The function
/// checks if the redeclaration might have an exception specification and
/// validates compatibility and merges the specs if necessary.
void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) {
// Shortcut if exceptions are disabled.
if (!getLangOpts().CXXExceptions)
return;
assert(Context.hasSameType(New->getType(), Old->getType()) &&
"Should only be called if types are otherwise the same.");
QualType NewType = New->getType();
QualType OldType = Old->getType();
// We're only interested in pointers and references to functions, as well
// as pointers to member functions.
if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
NewType = R->getPointeeType();
OldType = OldType->getAs<ReferenceType>()->getPointeeType();
} else if (const PointerType *P = NewType->getAs<PointerType>()) {
NewType = P->getPointeeType();
OldType = OldType->getAs<PointerType>()->getPointeeType();
} else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
NewType = M->getPointeeType();
OldType = OldType->getAs<MemberPointerType>()->getPointeeType();
}
if (!NewType->isFunctionProtoType())
return;
// There's lots of special cases for functions. For function pointers, system
// libraries are hopefully not as broken so that we don't need these
// workarounds.
if (CheckEquivalentExceptionSpec(
OldType->getAs<FunctionProtoType>(), Old->getLocation(),
NewType->getAs<FunctionProtoType>(), New->getLocation())) {
New->setInvalidDecl();
}
}
/// CheckCXXDefaultArguments - Verify that the default arguments for a
/// function declaration are well-formed according to C++
/// [dcl.fct.default].
void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
unsigned NumParams = FD->getNumParams();
unsigned p;
bool IsLambda = FD->getOverloadedOperator() == OO_Call &&
isa<CXXMethodDecl>(FD) &&
cast<CXXMethodDecl>(FD)->getParent()->isLambda();
// Find first parameter with a default argument
for (p = 0; p < NumParams; ++p) {
ParmVarDecl *Param = FD->getParamDecl(p);
if (Param->hasDefaultArg()) {
// C++11 [expr.prim.lambda]p5:
// [...] Default arguments (8.3.6) shall not be specified in the
// parameter-declaration-clause of a lambda-declarator.
//
// FIXME: Core issue 974 strikes this sentence, we only provide an
// extension warning.
if (IsLambda)
Diag(Param->getLocation(), diag::ext_lambda_default_arguments)
<< Param->getDefaultArgRange();
break;
}
}
// C++ [dcl.fct.default]p4:
// In a given function declaration, all parameters
// subsequent to a parameter with a default argument shall
// have default arguments supplied in this or previous
// declarations. A default argument shall not be redefined
// by a later declaration (not even to the same value).
unsigned LastMissingDefaultArg = 0;
for (; p < NumParams; ++p) {
ParmVarDecl *Param = FD->getParamDecl(p);
if (!Param->hasDefaultArg()) {
if (Param->isInvalidDecl())
/* We already complained about this parameter. */;
else if (Param->getIdentifier())
Diag(Param->getLocation(),
diag::err_param_default_argument_missing_name)
<< Param->getIdentifier();
else
Diag(Param->getLocation(),
diag::err_param_default_argument_missing);
LastMissingDefaultArg = p;
}
}
if (LastMissingDefaultArg > 0) {
// Some default arguments were missing. Clear out all of the
// default arguments up to (and including) the last missing
// default argument, so that we leave the function parameters
// in a semantically valid state.
for (p = 0; p <= LastMissingDefaultArg; ++p) {
ParmVarDecl *Param = FD->getParamDecl(p);
if (Param->hasDefaultArg()) {
Param->setDefaultArg(0);
}
}
}
}
// CheckConstexprParameterTypes - Check whether a function's parameter types
// are all literal types. If so, return true. If not, produce a suitable
// diagnostic and return false.
static bool CheckConstexprParameterTypes(Sema &SemaRef,
const FunctionDecl *FD) {
unsigned ArgIndex = 0;
const FunctionProtoType *FT = FD->getType()->getAs<FunctionProtoType>();
for (FunctionProtoType::arg_type_iterator i = FT->arg_type_begin(),
e = FT->arg_type_end(); i != e; ++i, ++ArgIndex) {
const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
SourceLocation ParamLoc = PD->getLocation();
if (!(*i)->isDependentType() &&
SemaRef.RequireLiteralType(ParamLoc, *i,
diag::err_constexpr_non_literal_param,
ArgIndex+1, PD->getSourceRange(),
isa<CXXConstructorDecl>(FD)))
return false;
}
return true;
}
// CheckConstexprFunctionDecl - Check whether a function declaration satisfies
// the requirements of a constexpr function definition or a constexpr
// constructor definition. If so, return true. If not, produce appropriate
// diagnostics and return false.
//
// This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
bool Sema::CheckConstexprFunctionDecl(const FunctionDecl *NewFD) {
const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
if (MD && MD->isInstance()) {
// C++11 [dcl.constexpr]p4:
// The definition of a constexpr constructor shall satisfy the following
// constraints:
// - the class shall not have any virtual base classes;
const CXXRecordDecl *RD = MD->getParent();
if (RD->getNumVBases()) {
Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
<< isa<CXXConstructorDecl>(NewFD) << RD->isStruct()
<< RD->getNumVBases();
for (CXXRecordDecl::base_class_const_iterator I = RD->vbases_begin(),
E = RD->vbases_end(); I != E; ++I)
Diag(I->getLocStart(),
diag::note_constexpr_virtual_base_here) << I->getSourceRange();
return false;
}
}
if (!isa<CXXConstructorDecl>(NewFD)) {
// C++11 [dcl.constexpr]p3:
// The definition of a constexpr function shall satisfy the following
// constraints:
// - it shall not be virtual;
const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
if (Method && Method->isVirtual()) {
Diag(NewFD->getLocation(), diag::err_constexpr_virtual);
// If it's not obvious why this function is virtual, find an overridden
// function which uses the 'virtual' keyword.
const CXXMethodDecl *WrittenVirtual = Method;
while (!WrittenVirtual->isVirtualAsWritten())
WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
if (WrittenVirtual != Method)
Diag(WrittenVirtual->getLocation(),
diag::note_overridden_virtual_function);
return false;
}
// - its return type shall be a literal type;
QualType RT = NewFD->getResultType();
if (!RT->isDependentType() &&
RequireLiteralType(NewFD->getLocation(), RT,
diag::err_constexpr_non_literal_return))
return false;
}
// - each of its parameter types shall be a literal type;
if (!CheckConstexprParameterTypes(*this, NewFD))
return false;
return true;
}
/// Check the given declaration statement is legal within a constexpr function
/// body. C++0x [dcl.constexpr]p3,p4.
///
/// \return true if the body is OK, false if we have diagnosed a problem.
static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
DeclStmt *DS) {
// C++0x [dcl.constexpr]p3 and p4:
// The definition of a constexpr function(p3) or constructor(p4) [...] shall
// contain only
for (DeclStmt::decl_iterator DclIt = DS->decl_begin(),
DclEnd = DS->decl_end(); DclIt != DclEnd; ++DclIt) {
switch ((*DclIt)->getKind()) {
case Decl::StaticAssert:
case Decl::Using:
case Decl::UsingShadow:
case Decl::UsingDirective:
case Decl::UnresolvedUsingTypename:
// - static_assert-declarations
// - using-declarations,
// - using-directives,
continue;
case Decl::Typedef:
case Decl::TypeAlias: {
// - typedef declarations and alias-declarations that do not define
// classes or enumerations,
TypedefNameDecl *TN = cast<TypedefNameDecl>(*DclIt);
if (TN->getUnderlyingType()->isVariablyModifiedType()) {
// Don't allow variably-modified types in constexpr functions.
TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
<< TL.getSourceRange() << TL.getType()
<< isa<CXXConstructorDecl>(Dcl);
return false;
}
continue;
}
case Decl::Enum:
case Decl::CXXRecord:
// As an extension, we allow the declaration (but not the definition) of
// classes and enumerations in all declarations, not just in typedef and
// alias declarations.
if (cast<TagDecl>(*DclIt)->isThisDeclarationADefinition()) {
SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_type_definition)
<< isa<CXXConstructorDecl>(Dcl);
return false;
}
continue;
case Decl::Var:
SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_var_declaration)
<< isa<CXXConstructorDecl>(Dcl);
return false;
default:
SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_body_invalid_stmt)
<< isa<CXXConstructorDecl>(Dcl);
return false;
}
}
return true;
}
/// Check that the given field is initialized within a constexpr constructor.
///
/// \param Dcl The constexpr constructor being checked.
/// \param Field The field being checked. This may be a member of an anonymous
/// struct or union nested within the class being checked.
/// \param Inits All declarations, including anonymous struct/union members and
/// indirect members, for which any initialization was provided.
/// \param Diagnosed Set to true if an error is produced.
static void CheckConstexprCtorInitializer(Sema &SemaRef,
const FunctionDecl *Dcl,
FieldDecl *Field,
llvm::SmallSet<Decl*, 16> &Inits,
bool &Diagnosed) {
if (Field->isUnnamedBitfield())
return;
if (Field->isAnonymousStructOrUnion() &&
Field->getType()->getAsCXXRecordDecl()->isEmpty())
return;
if (!Inits.count(Field)) {
if (!Diagnosed) {
SemaRef.Diag(Dcl->getLocation(), diag::err_constexpr_ctor_missing_init);
Diagnosed = true;
}
SemaRef.Diag(Field->getLocation(), diag::note_constexpr_ctor_missing_init);
} else if (Field->isAnonymousStructOrUnion()) {
const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
for (RecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end();
I != E; ++I)
// If an anonymous union contains an anonymous struct of which any member
// is initialized, all members must be initialized.
if (!RD->isUnion() || Inits.count(*I))
CheckConstexprCtorInitializer(SemaRef, Dcl, *I, Inits, Diagnosed);
}
}
/// Check the body for the given constexpr function declaration only contains
/// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
///
/// \return true if the body is OK, false if we have diagnosed a problem.
bool Sema::CheckConstexprFunctionBody(const FunctionDecl *Dcl, Stmt *Body) {
if (isa<CXXTryStmt>(Body)) {
// C++11 [dcl.constexpr]p3:
// The definition of a constexpr function shall satisfy the following
// constraints: [...]
// - its function-body shall be = delete, = default, or a
// compound-statement
//
// C++11 [dcl.constexpr]p4:
// In the definition of a constexpr constructor, [...]
// - its function-body shall not be a function-try-block;
Diag(Body->getLocStart(), diag::err_constexpr_function_try_block)
<< isa<CXXConstructorDecl>(Dcl);
return false;
}
// - its function-body shall be [...] a compound-statement that contains only
CompoundStmt *CompBody = cast<CompoundStmt>(Body);
llvm::SmallVector<SourceLocation, 4> ReturnStmts;
for (CompoundStmt::body_iterator BodyIt = CompBody->body_begin(),
BodyEnd = CompBody->body_end(); BodyIt != BodyEnd; ++BodyIt) {
switch ((*BodyIt)->getStmtClass()) {
case Stmt::NullStmtClass:
// - null statements,
continue;
case Stmt::DeclStmtClass:
// - static_assert-declarations
// - using-declarations,
// - using-directives,
// - typedef declarations and alias-declarations that do not define
// classes or enumerations,
if (!CheckConstexprDeclStmt(*this, Dcl, cast<DeclStmt>(*BodyIt)))
return false;
continue;
case Stmt::ReturnStmtClass:
// - and exactly one return statement;
if (isa<CXXConstructorDecl>(Dcl))
break;
ReturnStmts.push_back((*BodyIt)->getLocStart());
continue;
default:
break;
}
Diag((*BodyIt)->getLocStart(), diag::err_constexpr_body_invalid_stmt)
<< isa<CXXConstructorDecl>(Dcl);
return false;
}
if (const CXXConstructorDecl *Constructor
= dyn_cast<CXXConstructorDecl>(Dcl)) {
const CXXRecordDecl *RD = Constructor->getParent();
// DR1359:
// - every non-variant non-static data member and base class sub-object
// shall be initialized;
// - if the class is a non-empty union, or for each non-empty anonymous
// union member of a non-union class, exactly one non-static data member
// shall be initialized;
if (RD->isUnion()) {
if (Constructor->getNumCtorInitializers() == 0 && !RD->isEmpty()) {
Diag(Dcl->getLocation(), diag::err_constexpr_union_ctor_no_init);
return false;
}
} else if (!Constructor->isDependentContext() &&
!Constructor->isDelegatingConstructor()) {
assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases");
// Skip detailed checking if we have enough initializers, and we would
// allow at most one initializer per member.
bool AnyAnonStructUnionMembers = false;
unsigned Fields = 0;
for (CXXRecordDecl::field_iterator I = RD->field_begin(),
E = RD->field_end(); I != E; ++I, ++Fields) {
if (I->isAnonymousStructOrUnion()) {
AnyAnonStructUnionMembers = true;
break;
}
}
if (AnyAnonStructUnionMembers ||
Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
// Check initialization of non-static data members. Base classes are
// always initialized so do not need to be checked. Dependent bases
// might not have initializers in the member initializer list.
llvm::SmallSet<Decl*, 16> Inits;
for (CXXConstructorDecl::init_const_iterator
I = Constructor->init_begin(), E = Constructor->init_end();
I != E; ++I) {
if (FieldDecl *FD = (*I)->getMember())
Inits.insert(FD);
else if (IndirectFieldDecl *ID = (*I)->getIndirectMember())
Inits.insert(ID->chain_begin(), ID->chain_end());
}
bool Diagnosed = false;
for (CXXRecordDecl::field_iterator I = RD->field_begin(),
E = RD->field_end(); I != E; ++I)
CheckConstexprCtorInitializer(*this, Dcl, *I, Inits, Diagnosed);
if (Diagnosed)
return false;
}
}
} else {
if (ReturnStmts.empty()) {
Diag(Dcl->getLocation(), diag::err_constexpr_body_no_return);
return false;
}
if (ReturnStmts.size() > 1) {
Diag(ReturnStmts.back(), diag::err_constexpr_body_multiple_return);
for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
Diag(ReturnStmts[I], diag::note_constexpr_body_previous_return);
return false;
}
}
// C++11 [dcl.constexpr]p5:
// if no function argument values exist such that the function invocation
// substitution would produce a constant expression, the program is
// ill-formed; no diagnostic required.
// C++11 [dcl.constexpr]p3:
// - every constructor call and implicit conversion used in initializing the
// return value shall be one of those allowed in a constant expression.
// C++11 [dcl.constexpr]p4:
// - every constructor involved in initializing non-static data members and
// base class sub-objects shall be a constexpr constructor.
llvm::SmallVector<PartialDiagnosticAt, 8> Diags;
if (!Expr::isPotentialConstantExpr(Dcl, Diags)) {
Diag(Dcl->getLocation(), diag::err_constexpr_function_never_constant_expr)
<< isa<CXXConstructorDecl>(Dcl);
for (size_t I = 0, N = Diags.size(); I != N; ++I)
Diag(Diags[I].first, Diags[I].second);
return false;
}
return true;
}
/// isCurrentClassName - Determine whether the identifier II is the
/// name of the class type currently being defined. In the case of
/// nested classes, this will only return true if II is the name of
/// the innermost class.
bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *,
const CXXScopeSpec *SS) {
assert(getLangOpts().CPlusPlus && "No class names in C!");
CXXRecordDecl *CurDecl;
if (SS && SS->isSet() && !SS->isInvalid()) {
DeclContext *DC = computeDeclContext(*SS, true);
CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
} else
CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
if (CurDecl && CurDecl->getIdentifier())
return &II == CurDecl->getIdentifier();
else
return false;
}
/// \brief Check the validity of a C++ base class specifier.
///
/// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
/// and returns NULL otherwise.
CXXBaseSpecifier *
Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
SourceRange SpecifierRange,
bool Virtual, AccessSpecifier Access,
TypeSourceInfo *TInfo,
SourceLocation EllipsisLoc) {
QualType BaseType = TInfo->getType();
// C++ [class.union]p1:
// A union shall not have base classes.
if (Class->isUnion()) {
Diag(Class->getLocation(), diag::err_base_clause_on_union)
<< SpecifierRange;
return 0;
}
if (EllipsisLoc.isValid() &&
!TInfo->getType()->containsUnexpandedParameterPack()) {
Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
<< TInfo->getTypeLoc().getSourceRange();
EllipsisLoc = SourceLocation();
}
if (BaseType->isDependentType())
return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
Class->getTagKind() == TTK_Class,
Access, TInfo, EllipsisLoc);
SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
// Base specifiers must be record types.
if (!BaseType->isRecordType()) {
Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
return 0;
}
// C++ [class.union]p1:
// A union shall not be used as a base class.
if (BaseType->isUnionType()) {
Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
return 0;
}
// C++ [class.derived]p2:
// The class-name in a base-specifier shall not be an incompletely
// defined class.
if (RequireCompleteType(BaseLoc, BaseType,
diag::err_incomplete_base_class, SpecifierRange)) {
Class->setInvalidDecl();
return 0;
}
// If the base class is polymorphic or isn't empty, the new one is/isn't, too.
RecordDecl *BaseDecl = BaseType->getAs<RecordType>()->getDecl();
assert(BaseDecl && "Record type has no declaration");
BaseDecl = BaseDecl->getDefinition();
assert(BaseDecl && "Base type is not incomplete, but has no definition");
CXXRecordDecl * CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
assert(CXXBaseDecl && "Base type is not a C++ type");
// C++ [class]p3:
// If a class is marked final and it appears as a base-type-specifier in
// base-clause, the program is ill-formed.
if (CXXBaseDecl->hasAttr<FinalAttr>()) {
Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
<< CXXBaseDecl->getDeclName();
Diag(CXXBaseDecl->getLocation(), diag::note_previous_decl)
<< CXXBaseDecl->getDeclName();
return 0;
}
if (BaseDecl->isInvalidDecl())
Class->setInvalidDecl();
// Create the base specifier.
return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
Class->getTagKind() == TTK_Class,
Access, TInfo, EllipsisLoc);
}
/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
/// one entry in the base class list of a class specifier, for
/// example:
/// class foo : public bar, virtual private baz {
/// 'public bar' and 'virtual private baz' are each base-specifiers.
BaseResult
Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
bool Virtual, AccessSpecifier Access,
ParsedType basetype, SourceLocation BaseLoc,
SourceLocation EllipsisLoc) {
if (!classdecl)
return true;
AdjustDeclIfTemplate(classdecl);
CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
if (!Class)
return true;
TypeSourceInfo *TInfo = 0;
GetTypeFromParser(basetype, &TInfo);
if (EllipsisLoc.isInvalid() &&
DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
UPPC_BaseType))
return true;
if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
Virtual, Access, TInfo,
EllipsisLoc))
return BaseSpec;
else
Class->setInvalidDecl();
return true;
}
/// \brief Performs the actual work of attaching the given base class
/// specifiers to a C++ class.
bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class, CXXBaseSpecifier **Bases,
unsigned NumBases) {
if (NumBases == 0)
return false;
// Used to keep track of which base types we have already seen, so
// that we can properly diagnose redundant direct base types. Note
// that the key is always the unqualified canonical type of the base
// class.
std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
// Copy non-redundant base specifiers into permanent storage.
unsigned NumGoodBases = 0;
bool Invalid = false;
for (unsigned idx = 0; idx < NumBases; ++idx) {
QualType NewBaseType
= Context.getCanonicalType(Bases[idx]->getType());
NewBaseType = NewBaseType.getLocalUnqualifiedType();
CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
if (KnownBase) {
// C++ [class.mi]p3:
// A class shall not be specified as a direct base class of a
// derived class more than once.
Diag(Bases[idx]->getLocStart(),
diag::err_duplicate_base_class)
<< KnownBase->getType()
<< Bases[idx]->getSourceRange();
// Delete the duplicate base class specifier; we're going to
// overwrite its pointer later.
Context.Deallocate(Bases[idx]);
Invalid = true;
} else {
// Okay, add this new base class.
KnownBase = Bases[idx];
Bases[NumGoodBases++] = Bases[idx];
if (const RecordType *Record = NewBaseType->getAs<RecordType>())
if (const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl()))
if (RD->hasAttr<WeakAttr>())
Class->addAttr(::new (Context) WeakAttr(SourceRange(), Context));
}
}
// Attach the remaining base class specifiers to the derived class.
Class->setBases(Bases, NumGoodBases);
// Delete the remaining (good) base class specifiers, since their
// data has been copied into the CXXRecordDecl.
for (unsigned idx = 0; idx < NumGoodBases; ++idx)
Context.Deallocate(Bases[idx]);
return Invalid;
}
/// ActOnBaseSpecifiers - Attach the given base specifiers to the
/// class, after checking whether there are any duplicate base
/// classes.
void Sema::ActOnBaseSpecifiers(Decl *ClassDecl, CXXBaseSpecifier **Bases,
unsigned NumBases) {
if (!ClassDecl || !Bases || !NumBases)
return;
AdjustDeclIfTemplate(ClassDecl);
AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl),
(CXXBaseSpecifier**)(Bases), NumBases);
}
static CXXRecordDecl *GetClassForType(QualType T) {
if (const RecordType *RT = T->getAs<RecordType>())
return cast<CXXRecordDecl>(RT->getDecl());
else if (const InjectedClassNameType *ICT = T->getAs<InjectedClassNameType>())
return ICT->getDecl();
else
return 0;
}
/// \brief Determine whether the type \p Derived is a C++ class that is
/// derived from the type \p Base.
bool Sema::IsDerivedFrom(QualType Derived, QualType Base) {
if (!getLangOpts().CPlusPlus)
return false;
CXXRecordDecl *DerivedRD = GetClassForType(Derived);
if (!DerivedRD)
return false;
CXXRecordDecl *BaseRD = GetClassForType(Base);
if (!BaseRD)
return false;
// FIXME: instantiate DerivedRD if necessary. We need a PoI for this.
return DerivedRD->hasDefinition() && DerivedRD->isDerivedFrom(BaseRD);
}
/// \brief Determine whether the type \p Derived is a C++ class that is
/// derived from the type \p Base.
bool Sema::IsDerivedFrom(QualType Derived, QualType Base, CXXBasePaths &Paths) {
if (!getLangOpts().CPlusPlus)
return false;
CXXRecordDecl *DerivedRD = GetClassForType(Derived);
if (!DerivedRD)
return false;
CXXRecordDecl *BaseRD = GetClassForType(Base);
if (!BaseRD)
return false;
return DerivedRD->isDerivedFrom(BaseRD, Paths);
}
void Sema::BuildBasePathArray(const CXXBasePaths &Paths,
CXXCastPath &BasePathArray) {
assert(BasePathArray.empty() && "Base path array must be empty!");
assert(Paths.isRecordingPaths() && "Must record paths!");
const CXXBasePath &Path = Paths.front();
// We first go backward and check if we have a virtual base.
// FIXME: It would be better if CXXBasePath had the base specifier for
// the nearest virtual base.
unsigned Start = 0;
for (unsigned I = Path.size(); I != 0; --I) {
if (Path[I - 1].Base->isVirtual()) {
Start = I - 1;
break;
}
}
// Now add all bases.
for (unsigned I = Start, E = Path.size(); I != E; ++I)
BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
}
/// \brief Determine whether the given base path includes a virtual
/// base class.
bool Sema::BasePathInvolvesVirtualBase(const CXXCastPath &BasePath) {
for (CXXCastPath::const_iterator B = BasePath.begin(),
BEnd = BasePath.end();
B != BEnd; ++B)
if ((*B)->isVirtual())
return true;
return false;
}
/// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
/// conversion (where Derived and Base are class types) is
/// well-formed, meaning that the conversion is unambiguous (and
/// that all of the base classes are accessible). Returns true
/// and emits a diagnostic if the code is ill-formed, returns false
/// otherwise. Loc is the location where this routine should point to
/// if there is an error, and Range is the source range to highlight
/// if there is an error.
bool
Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
unsigned InaccessibleBaseID,
unsigned AmbigiousBaseConvID,
SourceLocation Loc, SourceRange Range,
DeclarationName Name,
CXXCastPath *BasePath) {
// First, determine whether the path from Derived to Base is
// ambiguous. This is slightly more expensive than checking whether
// the Derived to Base conversion exists, because here we need to
// explore multiple paths to determine if there is an ambiguity.
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
/*DetectVirtual=*/false);
bool DerivationOkay = IsDerivedFrom(Derived, Base, Paths);
assert(DerivationOkay &&
"Can only be used with a derived-to-base conversion");
(void)DerivationOkay;
if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType())) {
if (InaccessibleBaseID) {
// Check that the base class can be accessed.
switch (CheckBaseClassAccess(Loc, Base, Derived, Paths.front(),
InaccessibleBaseID)) {
case AR_inaccessible:
return true;
case AR_accessible:
case AR_dependent:
case AR_delayed:
break;
}
}
// Build a base path if necessary.
if (BasePath)
BuildBasePathArray(Paths, *BasePath);
return false;
}
// We know that the derived-to-base conversion is ambiguous, and
// we're going to produce a diagnostic. Perform the derived-to-base
// search just one more time to compute all of the possible paths so
// that we can print them out. This is more expensive than any of
// the previous derived-to-base checks we've done, but at this point
// performance isn't as much of an issue.
Paths.clear();
Paths.setRecordingPaths(true);
bool StillOkay = IsDerivedFrom(Derived, Base, Paths);
assert(StillOkay && "Can only be used with a derived-to-base conversion");
(void)StillOkay;
// Build up a textual representation of the ambiguous paths, e.g.,
// D -> B -> A, that will be used to illustrate the ambiguous
// conversions in the diagnostic. We only print one of the paths
// to each base class subobject.
std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
Diag(Loc, AmbigiousBaseConvID)
<< Derived << Base << PathDisplayStr << Range << Name;
return true;
}
bool
Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
SourceLocation Loc, SourceRange Range,
CXXCastPath *BasePath,
bool IgnoreAccess) {
return CheckDerivedToBaseConversion(Derived, Base,
IgnoreAccess ? 0
: diag::err_upcast_to_inaccessible_base,
diag::err_ambiguous_derived_to_base_conv,
Loc, Range, DeclarationName(),
BasePath);
}
/// @brief Builds a string representing ambiguous paths from a
/// specific derived class to different subobjects of the same base
/// class.
///
/// This function builds a string that can be used in error messages
/// to show the different paths that one can take through the
/// inheritance hierarchy to go from the derived class to different
/// subobjects of a base class. The result looks something like this:
/// @code
/// struct D -> struct B -> struct A
/// struct D -> struct C -> struct A
/// @endcode
std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
std::string PathDisplayStr;
std::set<unsigned> DisplayedPaths;
for (CXXBasePaths::paths_iterator Path = Paths.begin();
Path != Paths.end(); ++Path) {
if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
// We haven't displayed a path to this particular base
// class subobject yet.
PathDisplayStr += "\n ";
PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
for (CXXBasePath::const_iterator Element = Path->begin();
Element != Path->end(); ++Element)
PathDisplayStr += " -> " + Element->Base->getType().getAsString();
}
}
return PathDisplayStr;
}
//===----------------------------------------------------------------------===//
// C++ class member Handling
//===----------------------------------------------------------------------===//
/// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
bool Sema::ActOnAccessSpecifier(AccessSpecifier Access,
SourceLocation ASLoc,
SourceLocation ColonLoc,
AttributeList *Attrs) {
assert(Access != AS_none && "Invalid kind for syntactic access specifier!");
AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
ASLoc, ColonLoc);
CurContext->addHiddenDecl(ASDecl);
return ProcessAccessDeclAttributeList(ASDecl, Attrs);
}
/// CheckOverrideControl - Check C++11 override control semantics.
void Sema::CheckOverrideControl(Decl *D) {
const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
// Do we know which functions this declaration might be overriding?
bool OverridesAreKnown = !MD ||
(!MD->getParent()->hasAnyDependentBases() &&
!MD->getType()->isDependentType());
if (!MD || !MD->isVirtual()) {
if (OverridesAreKnown) {
if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
Diag(OA->getLocation(),
diag::override_keyword_only_allowed_on_virtual_member_functions)
<< "override" << FixItHint::CreateRemoval(OA->getLocation());
D->dropAttr<OverrideAttr>();
}
if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
Diag(FA->getLocation(),
diag::override_keyword_only_allowed_on_virtual_member_functions)
<< "final" << FixItHint::CreateRemoval(FA->getLocation());
D->dropAttr<FinalAttr>();
}
}
return;
}
if (!OverridesAreKnown)
return;
// C++11 [class.virtual]p5:
// If a virtual function is marked with the virt-specifier override and
// does not override a member function of a base class, the program is
// ill-formed.
bool HasOverriddenMethods =
MD->begin_overridden_methods() != MD->end_overridden_methods();
if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
<< MD->getDeclName();
}
/// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
/// function overrides a virtual member function marked 'final', according to
/// C++11 [class.virtual]p4.
bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
const CXXMethodDecl *Old) {
if (!Old->hasAttr<FinalAttr>())
return false;
Diag(New->getLocation(), diag::err_final_function_overridden)
<< New->getDeclName();
Diag(Old->getLocation(), diag::note_overridden_virtual_function);
return true;
}
static bool InitializationHasSideEffects(const FieldDecl &FD) {
const Type *T = FD.getType()->getBaseElementTypeUnsafe();
// FIXME: Destruction of ObjC lifetime types has side-effects.
if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
return !RD->isCompleteDefinition() ||
!RD->hasTrivialDefaultConstructor() ||
!RD->hasTrivialDestructor();
return false;
}
/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
/// bitfield width if there is one, 'InitExpr' specifies the initializer if
/// one has been parsed, and 'InitStyle' is set if an in-class initializer is
/// present (but parsing it has been deferred).
Decl *
Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
MultiTemplateParamsArg TemplateParameterLists,
Expr *BW, const VirtSpecifiers &VS,
InClassInitStyle InitStyle) {
const DeclSpec &DS = D.getDeclSpec();
DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
DeclarationName Name = NameInfo.getName();
SourceLocation Loc = NameInfo.getLoc();
// For anonymous bitfields, the location should point to the type.
if (Loc.isInvalid())
Loc = D.getLocStart();
Expr *BitWidth = static_cast<Expr*>(BW);
assert(isa<CXXRecordDecl>(CurContext));
assert(!DS.isFriendSpecified());
bool isFunc = D.isDeclarationOfFunction();
// C++ 9.2p6: A member shall not be declared to have automatic storage
// duration (auto, register) or with the extern storage-class-specifier.
// C++ 7.1.1p8: The mutable specifier can be applied only to names of class
// data members and cannot be applied to names declared const or static,
// and cannot be applied to reference members.
switch (DS.getStorageClassSpec()) {
case DeclSpec::SCS_unspecified:
case DeclSpec::SCS_typedef:
case DeclSpec::SCS_static:
// FALL THROUGH.
break;
case DeclSpec::SCS_mutable:
if (isFunc) {
if (DS.getStorageClassSpecLoc().isValid())
Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
else
Diag(DS.getThreadSpecLoc(), diag::err_mutable_function);
// FIXME: It would be nicer if the keyword was ignored only for this
// declarator. Otherwise we could get follow-up errors.
D.getMutableDeclSpec().ClearStorageClassSpecs();
}
break;
default:
if (DS.getStorageClassSpecLoc().isValid())
Diag(DS.getStorageClassSpecLoc(),
diag::err_storageclass_invalid_for_member);
else
Diag(DS.getThreadSpecLoc(), diag::err_storageclass_invalid_for_member);
D.getMutableDeclSpec().ClearStorageClassSpecs();
}
bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
!isFunc);
Decl *Member;
if (isInstField) {
CXXScopeSpec &SS = D.getCXXScopeSpec();
// Data members must have identifiers for names.
if (!Name.isIdentifier()) {
Diag(Loc, diag::err_bad_variable_name)
<< Name;
return 0;
}
IdentifierInfo *II = Name.getAsIdentifierInfo();
// Member field could not be with "template" keyword.
// So TemplateParameterLists should be empty in this case.
if (TemplateParameterLists.size()) {
TemplateParameterList* TemplateParams = TemplateParameterLists[0];
if (TemplateParams->size()) {
// There is no such thing as a member field template.
Diag(D.getIdentifierLoc(), diag::err_template_member)
<< II
<< SourceRange(TemplateParams->getTemplateLoc(),
TemplateParams->getRAngleLoc());
} else {
// There is an extraneous 'template<>' for this member.
Diag(TemplateParams->getTemplateLoc(),
diag::err_template_member_noparams)
<< II
<< SourceRange(TemplateParams->getTemplateLoc(),
TemplateParams->getRAngleLoc());
}
return 0;
}
if (SS.isSet() && !SS.isInvalid()) {
// The user provided a superfluous scope specifier inside a class
// definition:
//
// class X {
// int X::member;
// };
if (DeclContext *DC = computeDeclContext(SS, false))
diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc());
else
Diag(D.getIdentifierLoc(), diag::err_member_qualification)
<< Name << SS.getRange();
SS.clear();
}
Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D, BitWidth,
InitStyle, AS);
assert(Member && "HandleField never returns null");
} else {
assert(InitStyle == ICIS_NoInit);
Member = HandleDeclarator(S, D, TemplateParameterLists);
if (!Member) {
return 0;
}
// Non-instance-fields can't have a bitfield.
if (BitWidth) {
if (Member->isInvalidDecl()) {
// don't emit another diagnostic.
} else if (isa<VarDecl>(Member)) {
// C++ 9.6p3: A bit-field shall not be a static member.
// "static member 'A' cannot be a bit-field"
Diag(Loc, diag::err_static_not_bitfield)
<< Name << BitWidth->getSourceRange();
} else if (isa<TypedefDecl>(Member)) {
// "typedef member 'x' cannot be a bit-field"
Diag(Loc, diag::err_typedef_not_bitfield)
<< Name << BitWidth->getSourceRange();
} else {
// A function typedef ("typedef int f(); f a;").
// C++ 9.6p3: A bit-field shall have integral or enumeration type.
Diag(Loc, diag::err_not_integral_type_bitfield)
<< Name << cast<ValueDecl>(Member)->getType()
<< BitWidth->getSourceRange();
}
BitWidth = 0;
Member->setInvalidDecl();
}
Member->setAccess(AS);
// If we have declared a member function template, set the access of the
// templated declaration as well.
if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
FunTmpl->getTemplatedDecl()->setAccess(AS);
}
if (VS.isOverrideSpecified())
Member->addAttr(new (Context) OverrideAttr(VS.getOverrideLoc(), Context));
if (VS.isFinalSpecified())
Member->addAttr(new (Context) FinalAttr(VS.getFinalLoc(), Context));
if (VS.getLastLocation().isValid()) {
// Update the end location of a method that has a virt-specifiers.
if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
MD->setRangeEnd(VS.getLastLocation());
}
CheckOverrideControl(Member);
assert((Name || isInstField) && "No identifier for non-field ?");
if (isInstField) {
FieldDecl *FD = cast<FieldDecl>(Member);
FieldCollector->Add(FD);
if (Diags.getDiagnosticLevel(diag::warn_unused_private_field,
FD->getLocation())
!= DiagnosticsEngine::Ignored) {
// Remember all explicit private FieldDecls that have a name, no side
// effects and are not part of a dependent type declaration.
if (!FD->isImplicit() && FD->getDeclName() &&
FD->getAccess() == AS_private &&
!FD->hasAttr<UnusedAttr>() &&
!FD->getParent()->isDependentContext() &&
!InitializationHasSideEffects(*FD))
UnusedPrivateFields.insert(FD);
}
}
return Member;
}
/// ActOnCXXInClassMemberInitializer - This is invoked after parsing an
/// in-class initializer for a non-static C++ class member, and after
/// instantiating an in-class initializer in a class template. Such actions
/// are deferred until the class is complete.
void
Sema::ActOnCXXInClassMemberInitializer(Decl *D, SourceLocation InitLoc,
Expr *InitExpr) {
FieldDecl *FD = cast<FieldDecl>(D);
assert(FD->getInClassInitStyle() != ICIS_NoInit &&
"must set init style when field is created");
if (!InitExpr) {
FD->setInvalidDecl();
FD->removeInClassInitializer();
return;
}
if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
FD->setInvalidDecl();
FD->removeInClassInitializer();
return;
}
ExprResult Init = InitExpr;
if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
if (isa<InitListExpr>(InitExpr) && isStdInitializerList(FD->getType(), 0)) {
Diag(FD->getLocation(), diag::warn_dangling_std_initializer_list)
<< /*at end of ctor*/1 << InitExpr->getSourceRange();
}
Expr **Inits = &InitExpr;
unsigned NumInits = 1;
InitializedEntity Entity = InitializedEntity::InitializeMember(FD);
InitializationKind Kind = FD->getInClassInitStyle() == ICIS_ListInit
? InitializationKind::CreateDirectList(InitExpr->getLocStart())
: InitializationKind::CreateCopy(InitExpr->getLocStart(), InitLoc);
InitializationSequence Seq(*this, Entity, Kind, Inits, NumInits);
Init = Seq.Perform(*this, Entity, Kind, MultiExprArg(Inits, NumInits));
if (Init.isInvalid()) {
FD->setInvalidDecl();
return;
}
CheckImplicitConversions(Init.get(), InitLoc);
}
// C++0x [class.base.init]p7:
// The initialization of each base and member constitutes a
// full-expression.
Init = MaybeCreateExprWithCleanups(Init);
if (Init.isInvalid()) {
FD->setInvalidDecl();
return;
}
InitExpr = Init.release();
FD->setInClassInitializer(InitExpr);
}
/// \brief Find the direct and/or virtual base specifiers that
/// correspond to the given base type, for use in base initialization
/// within a constructor.
static bool FindBaseInitializer(Sema &SemaRef,
CXXRecordDecl *ClassDecl,
QualType BaseType,
const CXXBaseSpecifier *&DirectBaseSpec,
const CXXBaseSpecifier *&VirtualBaseSpec) {
// First, check for a direct base class.
DirectBaseSpec = 0;
for (CXXRecordDecl::base_class_const_iterator Base
= ClassDecl->bases_begin();
Base != ClassDecl->bases_end(); ++Base) {
if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base->getType())) {
// We found a direct base of this type. That's what we're
// initializing.
DirectBaseSpec = &*Base;
break;
}
}
// Check for a virtual base class.
// FIXME: We might be able to short-circuit this if we know in advance that
// there are no virtual bases.
VirtualBaseSpec = 0;
if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
// We haven't found a base yet; search the class hierarchy for a
// virtual base class.
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
/*DetectVirtual=*/false);
if (SemaRef.IsDerivedFrom(SemaRef.Context.getTypeDeclType(ClassDecl),
BaseType, Paths)) {
for (CXXBasePaths::paths_iterator Path = Paths.begin();
Path != Paths.end(); ++Path) {
if (Path->back().Base->isVirtual()) {
VirtualBaseSpec = Path->back().Base;
break;
}
}
}
}
return DirectBaseSpec || VirtualBaseSpec;
}
/// \brief Handle a C++ member initializer using braced-init-list syntax.
MemInitResult
Sema::ActOnMemInitializer(Decl *ConstructorD,
Scope *S,
CXXScopeSpec &SS,
IdentifierInfo *MemberOrBase,
ParsedType TemplateTypeTy,
const DeclSpec &DS,
SourceLocation IdLoc,
Expr *InitList,
SourceLocation EllipsisLoc) {
return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
DS, IdLoc, InitList,
EllipsisLoc);
}
/// \brief Handle a C++ member initializer using parentheses syntax.
MemInitResult
Sema::ActOnMemInitializer(Decl *ConstructorD,
Scope *S,
CXXScopeSpec &SS,
IdentifierInfo *MemberOrBase,
ParsedType TemplateTypeTy,
const DeclSpec &DS,
SourceLocation IdLoc,
SourceLocation LParenLoc,
Expr **Args, unsigned NumArgs,
SourceLocation RParenLoc,
SourceLocation EllipsisLoc) {
Expr *List = new (Context) ParenListExpr(Context, LParenLoc,
llvm::makeArrayRef(Args, NumArgs),
RParenLoc);
return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
DS, IdLoc, List, EllipsisLoc);
}
namespace {
// Callback to only accept typo corrections that can be a valid C++ member
// intializer: either a non-static field member or a base class.
class MemInitializerValidatorCCC : public CorrectionCandidateCallback {
public:
explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
: ClassDecl(ClassDecl) {}
virtual bool ValidateCandidate(const TypoCorrection &candidate) {
if (NamedDecl *ND = candidate.getCorrectionDecl()) {
if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
else
return isa<TypeDecl>(ND);
}
return false;
}
private:
CXXRecordDecl *ClassDecl;
};
}
/// \brief Handle a C++ member initializer.
MemInitResult
Sema::BuildMemInitializer(Decl *ConstructorD,
Scope *S,
CXXScopeSpec &SS,
IdentifierInfo *MemberOrBase,
ParsedType TemplateTypeTy,
const DeclSpec &DS,
SourceLocation IdLoc,
Expr *Init,
SourceLocation EllipsisLoc) {
if (!ConstructorD)
return true;
AdjustDeclIfTemplate(ConstructorD);
CXXConstructorDecl *Constructor
= dyn_cast<CXXConstructorDecl>(ConstructorD);
if (!Constructor) {
// The user wrote a constructor initializer on a function that is
// not a C++ constructor. Ignore the error for now, because we may
// have more member initializers coming; we'll diagnose it just
// once in ActOnMemInitializers.
return true;
}
CXXRecordDecl *ClassDecl = Constructor->getParent();
// C++ [class.base.init]p2:
// Names in a mem-initializer-id are looked up in the scope of the
// constructor's class and, if not found in that scope, are looked
// up in the scope containing the constructor's definition.
// [Note: if the constructor's class contains a member with the
// same name as a direct or virtual base class of the class, a
// mem-initializer-id naming the member or base class and composed
// of a single identifier refers to the class member. A
// mem-initializer-id for the hidden base class may be specified
// using a qualified name. ]
if (!SS.getScopeRep() && !TemplateTypeTy) {
// Look for a member, first.
DeclContext::lookup_result Result
= ClassDecl->lookup(MemberOrBase);
if (Result.first != Result.second) {
ValueDecl *Member;
if ((Member = dyn_cast<FieldDecl>(*Result.first)) ||
(Member = dyn_cast<IndirectFieldDecl>(*Result.first))) {
if (EllipsisLoc.isValid())
Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
<< MemberOrBase
<< SourceRange(IdLoc, Init->getSourceRange().getEnd());
return BuildMemberInitializer(Member, Init, IdLoc);
}
}
}
// It didn't name a member, so see if it names a class.
QualType BaseType;
TypeSourceInfo *TInfo = 0;
if (TemplateTypeTy) {
BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
} else if (DS.getTypeSpecType() == TST_decltype) {
BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
} else {
LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
LookupParsedName(R, S, &SS);
TypeDecl *TyD = R.getAsSingle<TypeDecl>();
if (!TyD) {
if (R.isAmbiguous()) return true;
// We don't want access-control diagnostics here.
R.suppressDiagnostics();
if (SS.isSet() && isDependentScopeSpecifier(SS)) {
bool NotUnknownSpecialization = false;
DeclContext *DC = computeDeclContext(SS, false);
if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
NotUnknownSpecialization = !Record->hasAnyDependentBases();
if (!NotUnknownSpecialization) {
// When the scope specifier can refer to a member of an unknown
// specialization, we take it as a type name.
BaseType = CheckTypenameType(ETK_None, SourceLocation(),
SS.getWithLocInContext(Context),
*MemberOrBase, IdLoc);
if (BaseType.isNull())
return true;
R.clear();
R.setLookupName(MemberOrBase);
}
}
// If no results were found, try to correct typos.
TypoCorrection Corr;
MemInitializerValidatorCCC Validator(ClassDecl);
if (R.empty() && BaseType.isNull() &&
(Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
Validator, ClassDecl))) {
std::string CorrectedStr(Corr.getAsString(getLangOpts()));
std::string CorrectedQuotedStr(Corr.getQuoted(getLangOpts()));
if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
// We have found a non-static data member with a similar
// name to what was typed; complain and initialize that
// member.
Diag(R.getNameLoc(), diag::err_mem_init_not_member_or_class_suggest)
<< MemberOrBase << true << CorrectedQuotedStr
<< FixItHint::CreateReplacement(R.getNameLoc(), CorrectedStr);
Diag(Member->getLocation(), diag::note_previous_decl)
<< CorrectedQuotedStr;
return BuildMemberInitializer(Member, Init, IdLoc);
} else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
const CXXBaseSpecifier *DirectBaseSpec;
const CXXBaseSpecifier *VirtualBaseSpec;
if (FindBaseInitializer(*this, ClassDecl,
Context.getTypeDeclType(Type),
DirectBaseSpec, VirtualBaseSpec)) {
// We have found a direct or virtual base class with a
// similar name to what was typed; complain and initialize
// that base class.
Diag(R.getNameLoc(), diag::err_mem_init_not_member_or_class_suggest)
<< MemberOrBase << false << CorrectedQuotedStr
<< FixItHint::CreateReplacement(R.getNameLoc(), CorrectedStr);
const CXXBaseSpecifier *BaseSpec = DirectBaseSpec? DirectBaseSpec
: VirtualBaseSpec;
Diag(BaseSpec->getLocStart(),
diag::note_base_class_specified_here)
<< BaseSpec->getType()
<< BaseSpec->getSourceRange();
TyD = Type;
}
}
}
if (!TyD && BaseType.isNull()) {
Diag(IdLoc, diag::err_mem_init_not_member_or_class)
<< MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
return true;
}
}
if (BaseType.isNull()) {
BaseType = Context.getTypeDeclType(TyD);
if (SS.isSet()) {
NestedNameSpecifier *Qualifier =
static_cast<NestedNameSpecifier*>(SS.getScopeRep());
// FIXME: preserve source range information
BaseType = Context.getElaboratedType(ETK_None, Qualifier, BaseType);
}
}
}
if (!TInfo)
TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
}
/// Checks a member initializer expression for cases where reference (or
/// pointer) members are bound to by-value parameters (or their addresses).
static void CheckForDanglingReferenceOrPointer(Sema &S, ValueDecl *Member,
Expr *Init,
SourceLocation IdLoc) {
QualType MemberTy = Member->getType();
// We only handle pointers and references currently.
// FIXME: Would this be relevant for ObjC object pointers? Or block pointers?
if (!MemberTy->isReferenceType() && !MemberTy->isPointerType())
return;
const bool IsPointer = MemberTy->isPointerType();
if (IsPointer) {
if (const UnaryOperator *Op
= dyn_cast<UnaryOperator>(Init->IgnoreParenImpCasts())) {
// The only case we're worried about with pointers requires taking the
// address.
if (Op->getOpcode() != UO_AddrOf)
return;
Init = Op->getSubExpr();
} else {
// We only handle address-of expression initializers for pointers.
return;
}
}
if (isa<MaterializeTemporaryExpr>(Init->IgnoreParens())) {
// Taking the address of a temporary will be diagnosed as a hard error.
if (IsPointer)
return;
S.Diag(Init->getExprLoc(), diag::warn_bind_ref_member_to_temporary)
<< Member << Init->getSourceRange();
} else if (const DeclRefExpr *DRE
= dyn_cast<DeclRefExpr>(Init->IgnoreParens())) {
// We only warn when referring to a non-reference parameter declaration.
const ParmVarDecl *Parameter = dyn_cast<ParmVarDecl>(DRE->getDecl());
if (!Parameter || Parameter->getType()->isReferenceType())
return;
S.Diag(Init->getExprLoc(),
IsPointer ? diag::warn_init_ptr_member_to_parameter_addr
: diag::warn_bind_ref_member_to_parameter)
<< Member << Parameter << Init->getSourceRange();
} else {
// Other initializers are fine.
return;
}
S.Diag(Member->getLocation(), diag::note_ref_or_ptr_member_declared_here)
<< (unsigned)IsPointer;
}
namespace {
class UninitializedFieldVisitor
: public EvaluatedExprVisitor<UninitializedFieldVisitor> {
Sema &S;
ValueDecl *VD;
public:
typedef EvaluatedExprVisitor<UninitializedFieldVisitor> Inherited;
UninitializedFieldVisitor(Sema &S, ValueDecl *VD) : Inherited(S.Context),
S(S), VD(VD) {
}
void HandleExpr(Expr *E) {
if (!E) return;
// Expressions like x(x) sometimes lack the surrounding expressions
// but need to be checked anyways.
HandleValue(E);
Visit(E);
}
void HandleValue(Expr *E) {
E = E->IgnoreParens();
if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
if (isa<EnumConstantDecl>(ME->getMemberDecl()))
return;
Expr *Base = E;
while (isa<MemberExpr>(Base)) {
ME = dyn_cast<MemberExpr>(Base);
if (VarDecl *VarD = dyn_cast<VarDecl>(ME->getMemberDecl()))
if (VarD->hasGlobalStorage())
return;
Base = ME->getBase();
}
if (VD == ME->getMemberDecl() && isa<CXXThisExpr>(Base)) {
unsigned diag = VD->getType()->isReferenceType()
? diag::warn_reference_field_is_uninit
: diag::warn_field_is_uninit;
S.Diag(ME->getExprLoc(), diag);
return;
}
}
if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
HandleValue(CO->getTrueExpr());
HandleValue(CO->getFalseExpr());
return;
}
if (BinaryConditionalOperator *BCO =
dyn_cast<BinaryConditionalOperator>(E)) {
HandleValue(BCO->getCommon());
HandleValue(BCO->getFalseExpr());
return;
}
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
switch (BO->getOpcode()) {
default:
return;
case(BO_PtrMemD):
case(BO_PtrMemI):
HandleValue(BO->getLHS());
return;
case(BO_Comma):
HandleValue(BO->getRHS());
return;
}
}
}
void VisitImplicitCastExpr(ImplicitCastExpr *E) {
if (E->getCastKind() == CK_LValueToRValue)
HandleValue(E->getSubExpr());
Inherited::VisitImplicitCastExpr(E);
}
void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
Expr *Callee = E->getCallee();
if (isa<MemberExpr>(Callee))
HandleValue(Callee);
Inherited::VisitCXXMemberCallExpr(E);
}
};
static void CheckInitExprContainsUninitializedFields(Sema &S, Expr *E,
ValueDecl *VD) {
UninitializedFieldVisitor(S, VD).HandleExpr(E);
}
} // namespace
MemInitResult
Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
SourceLocation IdLoc) {
FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
assert((DirectMember || IndirectMember) &&
"Member must be a FieldDecl or IndirectFieldDecl");
if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
return true;
if (Member->isInvalidDecl())
return true;
// Diagnose value-uses of fields to initialize themselves, e.g.
// foo(foo)
// where foo is not also a parameter to the constructor.
// TODO: implement -Wuninitialized and fold this into that framework.
Expr **Args;
unsigned NumArgs;
if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
Args = ParenList->getExprs();
NumArgs = ParenList->getNumExprs();
} else {
InitListExpr *InitList = cast<InitListExpr>(Init);
Args = InitList->getInits();
NumArgs = InitList->getNumInits();
}
if (getDiagnostics().getDiagnosticLevel(diag::warn_field_is_uninit, IdLoc)
!= DiagnosticsEngine::Ignored)
for (unsigned i = 0; i < NumArgs; ++i)
// FIXME: Warn about the case when other fields are used before being
// uninitialized. For example, let this field be the i'th field. When
// initializing the i'th field, throw a warning if any of the >= i'th
// fields are used, as they are not yet initialized.
// Right now we are only handling the case where the i'th field uses
// itself in its initializer.
CheckInitExprContainsUninitializedFields(*this, Args[i], Member);
SourceRange InitRange = Init->getSourceRange();
if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
// Can't check initialization for a member of dependent type or when
// any of the arguments are type-dependent expressions.
DiscardCleanupsInEvaluationContext();
} else {
bool InitList = false;
if (isa<InitListExpr>(Init)) {
InitList = true;
Args = &Init;
NumArgs = 1;
if (isStdInitializerList(Member->getType(), 0)) {
Diag(IdLoc, diag::warn_dangling_std_initializer_list)
<< /*at end of ctor*/1 << InitRange;
}
}
// Initialize the member.
InitializedEntity MemberEntity =
DirectMember ? InitializedEntity::InitializeMember(DirectMember, 0)
: InitializedEntity::InitializeMember(IndirectMember, 0);
InitializationKind Kind =
InitList ? InitializationKind::CreateDirectList(IdLoc)
: InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
InitRange.getEnd());
InitializationSequence InitSeq(*this, MemberEntity, Kind, Args, NumArgs);
ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind,
MultiExprArg(Args, NumArgs),
0);
if (MemberInit.isInvalid())
return true;
CheckImplicitConversions(MemberInit.get(),
InitRange.getBegin());
// C++0x [class.base.init]p7:
// The initialization of each base and member constitutes a
// full-expression.
MemberInit = MaybeCreateExprWithCleanups(MemberInit);
if (MemberInit.isInvalid())
return true;
// If we are in a dependent context, template instantiation will
// perform this type-checking again. Just save the arguments that we
// received.
// FIXME: This isn't quite ideal, since our ASTs don't capture all
// of the information that we have about the member
// initializer. However, deconstructing the ASTs is a dicey process,
// and this approach is far more likely to get the corner cases right.
if (CurContext->isDependentContext()) {
// The existing Init will do fine.
} else {
Init = MemberInit.get();
CheckForDanglingReferenceOrPointer(*this, Member, Init, IdLoc);
}
}
if (DirectMember) {
return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
InitRange.getBegin(), Init,
InitRange.getEnd());
} else {
return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
InitRange.getBegin(), Init,
InitRange.getEnd());
}
}
MemInitResult
Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
CXXRecordDecl *ClassDecl) {
SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
if (!LangOpts.CPlusPlus0x)
return Diag(NameLoc, diag::err_delegating_ctor)
<< TInfo->getTypeLoc().getLocalSourceRange();
Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
bool InitList = true;
Expr **Args = &Init;
unsigned NumArgs = 1;
if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
InitList = false;
Args = ParenList->getExprs();
NumArgs = ParenList->getNumExprs();
}
SourceRange InitRange = Init->getSourceRange();
// Initialize the object.
InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
QualType(ClassDecl->getTypeForDecl(), 0));
InitializationKind Kind =
InitList ? InitializationKind::CreateDirectList(NameLoc)
: InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
InitRange.getEnd());
InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args, NumArgs);
ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
MultiExprArg(Args, NumArgs),
0);
if (DelegationInit.isInvalid())
return true;
assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() &&
"Delegating constructor with no target?");
CheckImplicitConversions(DelegationInit.get(), InitRange.getBegin());
// C++0x [class.base.init]p7:
// The initialization of each base and member constitutes a
// full-expression.
DelegationInit = MaybeCreateExprWithCleanups(DelegationInit);
if (DelegationInit.isInvalid())
return true;
// If we are in a dependent context, template instantiation will
// perform this type-checking again. Just save the arguments that we
// received in a ParenListExpr.
// FIXME: This isn't quite ideal, since our ASTs don't capture all
// of the information that we have about the base
// initializer. However, deconstructing the ASTs is a dicey process,
// and this approach is far more likely to get the corner cases right.
if (CurContext->isDependentContext())
DelegationInit = Owned(Init);
return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
DelegationInit.takeAs<Expr>(),
InitRange.getEnd());
}
MemInitResult
Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
Expr *Init, CXXRecordDecl *ClassDecl,
SourceLocation EllipsisLoc) {
SourceLocation BaseLoc
= BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();
if (!BaseType->isDependentType() && !BaseType->isRecordType())
return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
<< BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
// C++ [class.base.init]p2:
// [...] Unless the mem-initializer-id names a nonstatic data
// member of the constructor's class or a direct or virtual base
// of that class, the mem-initializer is ill-formed. A
// mem-initializer-list can initialize a base class using any
// name that denotes that base class type.
bool Dependent = BaseType->isDependentType() || Init->isTypeDependent();
SourceRange InitRange = Init->getSourceRange();
if (EllipsisLoc.isValid()) {
// This is a pack expansion.
if (!BaseType->containsUnexpandedParameterPack()) {
Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
<< SourceRange(BaseLoc, InitRange.getEnd());
EllipsisLoc = SourceLocation();
}
} else {
// Check for any unexpanded parameter packs.
if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
return true;
if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
return true;
}
// Check for direct and virtual base classes.
const CXXBaseSpecifier *DirectBaseSpec = 0;
const CXXBaseSpecifier *VirtualBaseSpec = 0;
if (!Dependent) {
if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
BaseType))
return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
VirtualBaseSpec);
// C++ [base.class.init]p2:
// Unless the mem-initializer-id names a nonstatic data member of the
// constructor's class or a direct or virtual base of that class, the
// mem-initializer is ill-formed.
if (!DirectBaseSpec && !VirtualBaseSpec) {
// If the class has any dependent bases, then it's possible that
// one of those types will resolve to the same type as
// BaseType. Therefore, just treat this as a dependent base
// class initialization. FIXME: Should we try to check the
// initialization anyway? It seems odd.
if (ClassDecl->hasAnyDependentBases())
Dependent = true;
else
return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
<< BaseType << Context.getTypeDeclType(ClassDecl)
<< BaseTInfo->getTypeLoc().getLocalSourceRange();
}
}
if (Dependent) {
DiscardCleanupsInEvaluationContext();
return new (Context) CXXCtorInitializer(Context, BaseTInfo,
/*IsVirtual=*/false,
InitRange.getBegin(), Init,
InitRange.getEnd(), EllipsisLoc);
}
// C++ [base.class.init]p2:
// If a mem-initializer-id is ambiguous because it designates both
// a direct non-virtual base class and an inherited virtual base
// class, the mem-initializer is ill-formed.
if (DirectBaseSpec && VirtualBaseSpec)
return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
<< BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
CXXBaseSpecifier *BaseSpec = const_cast<CXXBaseSpecifier *>(DirectBaseSpec);
if (!BaseSpec)
BaseSpec = const_cast<CXXBaseSpecifier *>(VirtualBaseSpec);
// Initialize the base.
bool InitList = true;
Expr **Args = &Init;
unsigned NumArgs = 1;
if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
InitList = false;
Args = ParenList->getExprs();
NumArgs = ParenList->getNumExprs();
}
InitializedEntity BaseEntity =
InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
InitializationKind Kind =
InitList ? InitializationKind::CreateDirectList(BaseLoc)
: InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
InitRange.getEnd());
InitializationSequence InitSeq(*this, BaseEntity, Kind, Args, NumArgs);
ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind,
MultiExprArg(Args, NumArgs), 0);
if (BaseInit.isInvalid())
return true;
CheckImplicitConversions(BaseInit.get(), InitRange.getBegin());
// C++0x [class.base.init]p7:
// The initialization of each base and member constitutes a
// full-expression.
BaseInit = MaybeCreateExprWithCleanups(BaseInit);
if (BaseInit.isInvalid())
return true;
// If we are in a dependent context, template instantiation will
// perform this type-checking again. Just save the arguments that we
// received in a ParenListExpr.
// FIXME: This isn't quite ideal, since our ASTs don't capture all
// of the information that we have about the base
// initializer. However, deconstructing the ASTs is a dicey process,
// and this approach is far more likely to get the corner cases right.
if (CurContext->isDependentContext())
BaseInit = Owned(Init);
return new (Context) CXXCtorInitializer(Context, BaseTInfo,
BaseSpec->isVirtual(),
InitRange.getBegin(),
BaseInit.takeAs<Expr>(),
InitRange.getEnd(), EllipsisLoc);
}
// Create a static_cast\<T&&>(expr).
static Expr *CastForMoving(Sema &SemaRef, Expr *E) {
QualType ExprType = E->getType();
QualType TargetType = SemaRef.Context.getRValueReferenceType(ExprType);
SourceLocation ExprLoc = E->getLocStart();
TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
TargetType, ExprLoc);
return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
SourceRange(ExprLoc, ExprLoc),
E->getSourceRange()).take();
}
/// ImplicitInitializerKind - How an implicit base or member initializer should
/// initialize its base or member.
enum ImplicitInitializerKind {
IIK_Default,
IIK_Copy,
IIK_Move
};
static bool
BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
ImplicitInitializerKind ImplicitInitKind,
CXXBaseSpecifier *BaseSpec,
bool IsInheritedVirtualBase,
CXXCtorInitializer *&CXXBaseInit) {
InitializedEntity InitEntity
= InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
IsInheritedVirtualBase);
ExprResult BaseInit;
switch (ImplicitInitKind) {
case IIK_Default: {
InitializationKind InitKind
= InitializationKind::CreateDefault(Constructor->getLocation());
InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, 0, 0);
BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, MultiExprArg());
break;
}
case IIK_Move:
case IIK_Copy: {
bool Moving = ImplicitInitKind == IIK_Move;
ParmVarDecl *Param = Constructor->getParamDecl(0);
QualType ParamType = Param->getType().getNonReferenceType();
Expr *CopyCtorArg =
DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
SourceLocation(), Param, false,
Constructor->getLocation(), ParamType,
VK_LValue, 0);
SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
// Cast to the base class to avoid ambiguities.
QualType ArgTy =
SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
ParamType.getQualifiers());
if (Moving) {
CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
}
CXXCastPath BasePath;
BasePath.push_back(BaseSpec);
CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
CK_UncheckedDerivedToBase,
Moving ? VK_XValue : VK_LValue,
&BasePath).take();
InitializationKind InitKind
= InitializationKind::CreateDirect(Constructor->getLocation(),
SourceLocation(), SourceLocation());
InitializationSequence InitSeq(SemaRef, InitEntity, InitKind,
&CopyCtorArg, 1);
BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind,
MultiExprArg(&CopyCtorArg, 1));
break;
}
}
BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
if (BaseInit.isInvalid())
return true;
CXXBaseInit =
new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
SourceLocation()),
BaseSpec->isVirtual(),