bool VisitVarDecl(const VarDecl *D) {
// Bail out early if this location should not be checked.
if (doIgnore(D->getLocation())) {
return true;
}
const QualType qualType = D->getType();
// Bail out if this type is either an enum or does not look like a real
// value.
if (qualType->isEnumeralType() || qualType->isBooleanType() ||
qualType->isArithmeticType() == false) {
return true;
}
const Type *t = qualType.getTypePtrOrNull();
assert(t && "Type of arithmetic types has to be available.");
const std::string typeName = qualType.getAsString();
// If it is of the same type as "size_t" and does have "size_t" somewhere in
// its name we can go with it.
// Please note: This also allows a typedef for "unsigned long" to be named
// e.g. "size_type" without any size indicator - which may or may not be a
// good thing.
if (context->hasSameUnqualifiedType(qualType, context->getSizeType()) &&
typeName.find("size_t") != std::string::npos) {
return true;
}
// char_t and wchar_t are not subject to this rule.
const std::string needle = "char_t";
if (std::equal(needle.rbegin(), needle.rend(), typeName.rbegin())) {
return true;
}
const uint64_t typeSize = context->getTypeSize(t);
const std::string sizeStr = llvm::utostr(typeSize);
// For all remaining types, the number of occupied bits must be embedded in
// the typename.
if (typeName.rfind(sizeStr) == std::string::npos) {
reportError(D->getLocation());
}
return true;
}
static void SuggestInitializationFixit(Sema &S, const VarDecl *VD) {
// Don't issue a fixit if there is already an initializer.
if (VD->getInit())
return;
// Suggest possible initialization (if any).
const char *initialization = 0;
QualType VariableTy = VD->getType().getCanonicalType();
if (VariableTy->isObjCObjectPointerType() ||
VariableTy->isBlockPointerType()) {
// Check if 'nil' is defined.
if (S.PP.getMacroInfo(&S.getASTContext().Idents.get("nil")))
initialization = " = nil";
else
initialization = " = 0";
}
else if (VariableTy->isRealFloatingType())
initialization = " = 0.0";
else if (VariableTy->isBooleanType() && S.Context.getLangOptions().CPlusPlus)
initialization = " = false";
else if (VariableTy->isEnumeralType())
return;
else if (VariableTy->isPointerType() || VariableTy->isMemberPointerType()) {
// Check if 'NULL' is defined.
if (S.PP.getMacroInfo(&S.getASTContext().Idents.get("NULL")))
initialization = " = NULL";
else
initialization = " = 0";
}
else if (VariableTy->isScalarType())
initialization = " = 0";
if (initialization) {
SourceLocation loc = S.PP.getLocForEndOfToken(VD->getLocEnd());
S.Diag(loc, diag::note_var_fixit_add_initialization)
<< FixItHint::CreateInsertion(loc, initialization);
}
}
/// \brief Build a new nested-name-specifier for "identifier::", as described
/// by ActOnCXXNestedNameSpecifier.
///
/// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in
/// that it contains an extra parameter \p ScopeLookupResult, which provides
/// the result of name lookup within the scope of the nested-name-specifier
/// that was computed at template definition time.
///
/// If ErrorRecoveryLookup is true, then this call is used to improve error
/// recovery. This means that it should not emit diagnostics, it should
/// just return true on failure. It also means it should only return a valid
/// scope if it *knows* that the result is correct. It should not return in a
/// dependent context, for example. Nor will it extend \p SS with the scope
/// specifier.
bool Sema::BuildCXXNestedNameSpecifier(Scope *S,
IdentifierInfo &Identifier,
SourceLocation IdentifierLoc,
SourceLocation CCLoc,
QualType ObjectType,
bool EnteringContext,
CXXScopeSpec &SS,
NamedDecl *ScopeLookupResult,
bool ErrorRecoveryLookup) {
LookupResult Found(*this, &Identifier, IdentifierLoc,
LookupNestedNameSpecifierName);
// Determine where to perform name lookup
DeclContext *LookupCtx = 0;
bool isDependent = false;
if (!ObjectType.isNull()) {
// This nested-name-specifier occurs in a member access expression, e.g.,
// x->B::f, and we are looking into the type of the object.
assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist");
LookupCtx = computeDeclContext(ObjectType);
isDependent = ObjectType->isDependentType();
} else if (SS.isSet()) {
// This nested-name-specifier occurs after another nested-name-specifier,
// so look into the context associated with the prior nested-name-specifier.
LookupCtx = computeDeclContext(SS, EnteringContext);
isDependent = isDependentScopeSpecifier(SS);
Found.setContextRange(SS.getRange());
}
bool ObjectTypeSearchedInScope = false;
if (LookupCtx) {
// Perform "qualified" name lookup into the declaration context we
// computed, which is either the type of the base of a member access
// expression or the declaration context associated with a prior
// nested-name-specifier.
// The declaration context must be complete.
if (!LookupCtx->isDependentContext() &&
RequireCompleteDeclContext(SS, LookupCtx))
return true;
LookupQualifiedName(Found, LookupCtx);
if (!ObjectType.isNull() && Found.empty()) {
// C++ [basic.lookup.classref]p4:
// If the id-expression in a class member access is a qualified-id of
// the form
//
// class-name-or-namespace-name::...
//
// the class-name-or-namespace-name following the . or -> operator is
// looked up both in the context of the entire postfix-expression and in
// the scope of the class of the object expression. If the name is found
// only in the scope of the class of the object expression, the name
// shall refer to a class-name. If the name is found only in the
// context of the entire postfix-expression, the name shall refer to a
// class-name or namespace-name. [...]
//
// Qualified name lookup into a class will not find a namespace-name,
// so we do not need to diagnose that case specifically. However,
// this qualified name lookup may find nothing. In that case, perform
// unqualified name lookup in the given scope (if available) or
// reconstruct the result from when name lookup was performed at template
// definition time.
if (S)
LookupName(Found, S);
else if (ScopeLookupResult)
Found.addDecl(ScopeLookupResult);
ObjectTypeSearchedInScope = true;
}
} else if (!isDependent) {
// Perform unqualified name lookup in the current scope.
LookupName(Found, S);
}
// If we performed lookup into a dependent context and did not find anything,
// that's fine: just build a dependent nested-name-specifier.
if (Found.empty() && isDependent &&
!(LookupCtx && LookupCtx->isRecord() &&
(!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() ||
!cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases()))) {
// Don't speculate if we're just trying to improve error recovery.
if (ErrorRecoveryLookup)
return true;
// We were not able to compute the declaration context for a dependent
// base object type or prior nested-name-specifier, so this
// nested-name-specifier refers to an unknown specialization. Just build
// a dependent nested-name-specifier.
SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc);
return false;
}
// FIXME: Deal with ambiguities cleanly.
if (Found.empty() && !ErrorRecoveryLookup) {
// We haven't found anything, and we're not recovering from a
// different kind of error, so look for typos.
DeclarationName Name = Found.getLookupName();
TypoCorrection Corrected;
Found.clear();
if ((Corrected = CorrectTypo(Found.getLookupNameInfo(),
Found.getLookupKind(), S, &SS, LookupCtx,
EnteringContext, CTC_NoKeywords)) &&
isAcceptableNestedNameSpecifier(Corrected.getCorrectionDecl())) {
std::string CorrectedStr(Corrected.getAsString(getLangOptions()));
std::string CorrectedQuotedStr(Corrected.getQuoted(getLangOptions()));
if (LookupCtx)
Diag(Found.getNameLoc(), diag::err_no_member_suggest)
<< Name << LookupCtx << CorrectedQuotedStr << SS.getRange()
<< FixItHint::CreateReplacement(Found.getNameLoc(), CorrectedStr);
else
Diag(Found.getNameLoc(), diag::err_undeclared_var_use_suggest)
<< Name << CorrectedQuotedStr
<< FixItHint::CreateReplacement(Found.getNameLoc(), CorrectedStr);
if (NamedDecl *ND = Corrected.getCorrectionDecl()) {
Diag(ND->getLocation(), diag::note_previous_decl) << CorrectedQuotedStr;
Found.addDecl(ND);
}
Found.setLookupName(Corrected.getCorrection());
} else {
Found.setLookupName(&Identifier);
}
}
NamedDecl *SD = Found.getAsSingle<NamedDecl>();
if (isAcceptableNestedNameSpecifier(SD)) {
if (!ObjectType.isNull() && !ObjectTypeSearchedInScope) {
// C++ [basic.lookup.classref]p4:
// [...] If the name is found in both contexts, the
// class-name-or-namespace-name shall refer to the same entity.
//
// We already found the name in the scope of the object. Now, look
// into the current scope (the scope of the postfix-expression) to
// see if we can find the same name there. As above, if there is no
// scope, reconstruct the result from the template instantiation itself.
NamedDecl *OuterDecl;
if (S) {
LookupResult FoundOuter(*this, &Identifier, IdentifierLoc,
LookupNestedNameSpecifierName);
LookupName(FoundOuter, S);
OuterDecl = FoundOuter.getAsSingle<NamedDecl>();
} else
OuterDecl = ScopeLookupResult;
if (isAcceptableNestedNameSpecifier(OuterDecl) &&
OuterDecl->getCanonicalDecl() != SD->getCanonicalDecl() &&
(!isa<TypeDecl>(OuterDecl) || !isa<TypeDecl>(SD) ||
!Context.hasSameType(
Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)),
Context.getTypeDeclType(cast<TypeDecl>(SD))))) {
if (ErrorRecoveryLookup)
return true;
Diag(IdentifierLoc,
diag::err_nested_name_member_ref_lookup_ambiguous)
<< &Identifier;
Diag(SD->getLocation(), diag::note_ambig_member_ref_object_type)
<< ObjectType;
Diag(OuterDecl->getLocation(), diag::note_ambig_member_ref_scope);
// Fall through so that we'll pick the name we found in the object
// type, since that's probably what the user wanted anyway.
}
}
// If we're just performing this lookup for error-recovery purposes,
// don't extend the nested-name-specifier. Just return now.
if (ErrorRecoveryLookup)
return false;
if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD)) {
SS.Extend(Context, Namespace, IdentifierLoc, CCLoc);
return false;
}
if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD)) {
SS.Extend(Context, Alias, IdentifierLoc, CCLoc);
return false;
}
QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD));
TypeLocBuilder TLB;
if (isa<InjectedClassNameType>(T)) {
InjectedClassNameTypeLoc InjectedTL
= TLB.push<InjectedClassNameTypeLoc>(T);
InjectedTL.setNameLoc(IdentifierLoc);
} else if (isa<RecordType>(T)) {
RecordTypeLoc RecordTL = TLB.push<RecordTypeLoc>(T);
RecordTL.setNameLoc(IdentifierLoc);
} else if (isa<TypedefType>(T)) {
TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(T);
TypedefTL.setNameLoc(IdentifierLoc);
} else if (isa<EnumType>(T)) {
EnumTypeLoc EnumTL = TLB.push<EnumTypeLoc>(T);
EnumTL.setNameLoc(IdentifierLoc);
} else if (isa<TemplateTypeParmType>(T)) {
TemplateTypeParmTypeLoc TemplateTypeTL
= TLB.push<TemplateTypeParmTypeLoc>(T);
TemplateTypeTL.setNameLoc(IdentifierLoc);
} else if (isa<UnresolvedUsingType>(T)) {
UnresolvedUsingTypeLoc UnresolvedTL
= TLB.push<UnresolvedUsingTypeLoc>(T);
UnresolvedTL.setNameLoc(IdentifierLoc);
} else if (isa<SubstTemplateTypeParmType>(T)) {
SubstTemplateTypeParmTypeLoc TL
= TLB.push<SubstTemplateTypeParmTypeLoc>(T);
TL.setNameLoc(IdentifierLoc);
} else if (isa<SubstTemplateTypeParmPackType>(T)) {
SubstTemplateTypeParmPackTypeLoc TL
= TLB.push<SubstTemplateTypeParmPackTypeLoc>(T);
TL.setNameLoc(IdentifierLoc);
} else {
llvm_unreachable("Unhandled TypeDecl node in nested-name-specifier");
}
if (T->isEnumeralType())
Diag(IdentifierLoc, diag::warn_cxx98_compat_enum_nested_name_spec);
SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T),
CCLoc);
return false;
}
// Otherwise, we have an error case. If we don't want diagnostics, just
// return an error now.
if (ErrorRecoveryLookup)
return true;
// If we didn't find anything during our lookup, try again with
// ordinary name lookup, which can help us produce better error
// messages.
if (Found.empty()) {
Found.clear(LookupOrdinaryName);
LookupName(Found, S);
}
// In Microsoft mode, if we are within a templated function and we can't
// resolve Identifier, then extend the SS with Identifier. This will have
// the effect of resolving Identifier during template instantiation.
// The goal is to be able to resolve a function call whose
// nested-name-specifier is located inside a dependent base class.
// Example:
//
// class C {
// public:
// static void foo2() { }
// };
// template <class T> class A { public: typedef C D; };
//
// template <class T> class B : public A<T> {
// public:
// void foo() { D::foo2(); }
// };
if (getLangOptions().MicrosoftExt) {
DeclContext *DC = LookupCtx ? LookupCtx : CurContext;
if (DC->isDependentContext() && DC->isFunctionOrMethod()) {
SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc);
return false;
}
}
unsigned DiagID;
if (!Found.empty())
DiagID = diag::err_expected_class_or_namespace;
else if (SS.isSet()) {
Diag(IdentifierLoc, diag::err_no_member)
<< &Identifier << LookupCtx << SS.getRange();
return true;
} else
DiagID = diag::err_undeclared_var_use;
if (SS.isSet())
Diag(IdentifierLoc, DiagID) << &Identifier << SS.getRange();
else
Diag(IdentifierLoc, DiagID) << &Identifier;
return true;
}
/// Build a new nested-name-specifier for "identifier::", as described
/// by ActOnCXXNestedNameSpecifier.
///
/// \param S Scope in which the nested-name-specifier occurs.
/// \param IdInfo Parser information about an identifier in the
/// nested-name-spec.
/// \param EnteringContext If true, enter the context specified by the
/// nested-name-specifier.
/// \param SS Optional nested name specifier preceding the identifier.
/// \param ScopeLookupResult Provides the result of name lookup within the
/// scope of the nested-name-specifier that was computed at template
/// definition time.
/// \param ErrorRecoveryLookup Specifies if the method is called to improve
/// error recovery and what kind of recovery is performed.
/// \param IsCorrectedToColon If not null, suggestion of replace '::' -> ':'
/// are allowed. The bool value pointed by this parameter is set to
/// 'true' if the identifier is treated as if it was followed by ':',
/// not '::'.
/// \param OnlyNamespace If true, only considers namespaces in lookup.
///
/// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in
/// that it contains an extra parameter \p ScopeLookupResult, which provides
/// the result of name lookup within the scope of the nested-name-specifier
/// that was computed at template definition time.
///
/// If ErrorRecoveryLookup is true, then this call is used to improve error
/// recovery. This means that it should not emit diagnostics, it should
/// just return true on failure. It also means it should only return a valid
/// scope if it *knows* that the result is correct. It should not return in a
/// dependent context, for example. Nor will it extend \p SS with the scope
/// specifier.
bool Sema::BuildCXXNestedNameSpecifier(Scope *S, NestedNameSpecInfo &IdInfo,
bool EnteringContext, CXXScopeSpec &SS,
NamedDecl *ScopeLookupResult,
bool ErrorRecoveryLookup,
bool *IsCorrectedToColon,
bool OnlyNamespace) {
if (IdInfo.Identifier->isEditorPlaceholder())
return true;
LookupResult Found(*this, IdInfo.Identifier, IdInfo.IdentifierLoc,
OnlyNamespace ? LookupNamespaceName
: LookupNestedNameSpecifierName);
QualType ObjectType = GetTypeFromParser(IdInfo.ObjectType);
// Determine where to perform name lookup
DeclContext *LookupCtx = nullptr;
bool isDependent = false;
if (IsCorrectedToColon)
*IsCorrectedToColon = false;
if (!ObjectType.isNull()) {
// This nested-name-specifier occurs in a member access expression, e.g.,
// x->B::f, and we are looking into the type of the object.
assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist");
LookupCtx = computeDeclContext(ObjectType);
isDependent = ObjectType->isDependentType();
} else if (SS.isSet()) {
// This nested-name-specifier occurs after another nested-name-specifier,
// so look into the context associated with the prior nested-name-specifier.
LookupCtx = computeDeclContext(SS, EnteringContext);
isDependent = isDependentScopeSpecifier(SS);
Found.setContextRange(SS.getRange());
}
bool ObjectTypeSearchedInScope = false;
if (LookupCtx) {
// Perform "qualified" name lookup into the declaration context we
// computed, which is either the type of the base of a member access
// expression or the declaration context associated with a prior
// nested-name-specifier.
// The declaration context must be complete.
if (!LookupCtx->isDependentContext() &&
RequireCompleteDeclContext(SS, LookupCtx))
return true;
LookupQualifiedName(Found, LookupCtx);
if (!ObjectType.isNull() && Found.empty()) {
// C++ [basic.lookup.classref]p4:
// If the id-expression in a class member access is a qualified-id of
// the form
//
// class-name-or-namespace-name::...
//
// the class-name-or-namespace-name following the . or -> operator is
// looked up both in the context of the entire postfix-expression and in
// the scope of the class of the object expression. If the name is found
// only in the scope of the class of the object expression, the name
// shall refer to a class-name. If the name is found only in the
// context of the entire postfix-expression, the name shall refer to a
// class-name or namespace-name. [...]
//
// Qualified name lookup into a class will not find a namespace-name,
// so we do not need to diagnose that case specifically. However,
// this qualified name lookup may find nothing. In that case, perform
// unqualified name lookup in the given scope (if available) or
// reconstruct the result from when name lookup was performed at template
// definition time.
if (S)
LookupName(Found, S);
else if (ScopeLookupResult)
Found.addDecl(ScopeLookupResult);
ObjectTypeSearchedInScope = true;
}
} else if (!isDependent) {
// Perform unqualified name lookup in the current scope.
LookupName(Found, S);
}
if (Found.isAmbiguous())
return true;
// If we performed lookup into a dependent context and did not find anything,
// that's fine: just build a dependent nested-name-specifier.
if (Found.empty() && isDependent &&
!(LookupCtx && LookupCtx->isRecord() &&
(!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() ||
!cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases()))) {
// Don't speculate if we're just trying to improve error recovery.
if (ErrorRecoveryLookup)
return true;
// We were not able to compute the declaration context for a dependent
// base object type or prior nested-name-specifier, so this
// nested-name-specifier refers to an unknown specialization. Just build
// a dependent nested-name-specifier.
SS.Extend(Context, IdInfo.Identifier, IdInfo.IdentifierLoc, IdInfo.CCLoc);
return false;
}
if (Found.empty() && !ErrorRecoveryLookup) {
// If identifier is not found as class-name-or-namespace-name, but is found
// as other entity, don't look for typos.
LookupResult R(*this, Found.getLookupNameInfo(), LookupOrdinaryName);
if (LookupCtx)
LookupQualifiedName(R, LookupCtx);
else if (S && !isDependent)
LookupName(R, S);
if (!R.empty()) {
// Don't diagnose problems with this speculative lookup.
R.suppressDiagnostics();
// The identifier is found in ordinary lookup. If correction to colon is
// allowed, suggest replacement to ':'.
if (IsCorrectedToColon) {
*IsCorrectedToColon = true;
Diag(IdInfo.CCLoc, diag::err_nested_name_spec_is_not_class)
<< IdInfo.Identifier << getLangOpts().CPlusPlus
<< FixItHint::CreateReplacement(IdInfo.CCLoc, ":");
if (NamedDecl *ND = R.getAsSingle<NamedDecl>())
Diag(ND->getLocation(), diag::note_declared_at);
return true;
}
// Replacement '::' -> ':' is not allowed, just issue respective error.
Diag(R.getNameLoc(), OnlyNamespace
? unsigned(diag::err_expected_namespace_name)
: unsigned(diag::err_expected_class_or_namespace))
<< IdInfo.Identifier << getLangOpts().CPlusPlus;
if (NamedDecl *ND = R.getAsSingle<NamedDecl>())
Diag(ND->getLocation(), diag::note_entity_declared_at)
<< IdInfo.Identifier;
return true;
}
}
if (Found.empty() && !ErrorRecoveryLookup && !getLangOpts().MSVCCompat) {
// We haven't found anything, and we're not recovering from a
// different kind of error, so look for typos.
DeclarationName Name = Found.getLookupName();
Found.clear();
NestedNameSpecifierValidatorCCC CCC(*this);
if (TypoCorrection Corrected = CorrectTypo(
Found.getLookupNameInfo(), Found.getLookupKind(), S, &SS, CCC,
CTK_ErrorRecovery, LookupCtx, EnteringContext)) {
if (LookupCtx) {
bool DroppedSpecifier =
Corrected.WillReplaceSpecifier() &&
Name.getAsString() == Corrected.getAsString(getLangOpts());
if (DroppedSpecifier)
SS.clear();
diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest)
<< Name << LookupCtx << DroppedSpecifier
<< SS.getRange());
} else
diagnoseTypo(Corrected, PDiag(diag::err_undeclared_var_use_suggest)
<< Name);
if (Corrected.getCorrectionSpecifier())
SS.MakeTrivial(Context, Corrected.getCorrectionSpecifier(),
SourceRange(Found.getNameLoc()));
if (NamedDecl *ND = Corrected.getFoundDecl())
Found.addDecl(ND);
Found.setLookupName(Corrected.getCorrection());
} else {
Found.setLookupName(IdInfo.Identifier);
}
}
NamedDecl *SD =
Found.isSingleResult() ? Found.getRepresentativeDecl() : nullptr;
bool IsExtension = false;
bool AcceptSpec = isAcceptableNestedNameSpecifier(SD, &IsExtension);
if (!AcceptSpec && IsExtension) {
AcceptSpec = true;
Diag(IdInfo.IdentifierLoc, diag::ext_nested_name_spec_is_enum);
}
if (AcceptSpec) {
if (!ObjectType.isNull() && !ObjectTypeSearchedInScope &&
!getLangOpts().CPlusPlus11) {
// C++03 [basic.lookup.classref]p4:
// [...] If the name is found in both contexts, the
// class-name-or-namespace-name shall refer to the same entity.
//
// We already found the name in the scope of the object. Now, look
// into the current scope (the scope of the postfix-expression) to
// see if we can find the same name there. As above, if there is no
// scope, reconstruct the result from the template instantiation itself.
//
// Note that C++11 does *not* perform this redundant lookup.
NamedDecl *OuterDecl;
if (S) {
LookupResult FoundOuter(*this, IdInfo.Identifier, IdInfo.IdentifierLoc,
LookupNestedNameSpecifierName);
LookupName(FoundOuter, S);
OuterDecl = FoundOuter.getAsSingle<NamedDecl>();
} else
OuterDecl = ScopeLookupResult;
if (isAcceptableNestedNameSpecifier(OuterDecl) &&
OuterDecl->getCanonicalDecl() != SD->getCanonicalDecl() &&
(!isa<TypeDecl>(OuterDecl) || !isa<TypeDecl>(SD) ||
!Context.hasSameType(
Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)),
Context.getTypeDeclType(cast<TypeDecl>(SD))))) {
if (ErrorRecoveryLookup)
return true;
Diag(IdInfo.IdentifierLoc,
diag::err_nested_name_member_ref_lookup_ambiguous)
<< IdInfo.Identifier;
Diag(SD->getLocation(), diag::note_ambig_member_ref_object_type)
<< ObjectType;
Diag(OuterDecl->getLocation(), diag::note_ambig_member_ref_scope);
// Fall through so that we'll pick the name we found in the object
// type, since that's probably what the user wanted anyway.
}
}
if (auto *TD = dyn_cast_or_null<TypedefNameDecl>(SD))
MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false);
// If we're just performing this lookup for error-recovery purposes,
// don't extend the nested-name-specifier. Just return now.
if (ErrorRecoveryLookup)
return false;
// The use of a nested name specifier may trigger deprecation warnings.
DiagnoseUseOfDecl(SD, IdInfo.CCLoc);
if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD)) {
SS.Extend(Context, Namespace, IdInfo.IdentifierLoc, IdInfo.CCLoc);
return false;
}
if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD)) {
SS.Extend(Context, Alias, IdInfo.IdentifierLoc, IdInfo.CCLoc);
return false;
}
QualType T =
Context.getTypeDeclType(cast<TypeDecl>(SD->getUnderlyingDecl()));
TypeLocBuilder TLB;
if (isa<InjectedClassNameType>(T)) {
InjectedClassNameTypeLoc InjectedTL
= TLB.push<InjectedClassNameTypeLoc>(T);
InjectedTL.setNameLoc(IdInfo.IdentifierLoc);
} else if (isa<RecordType>(T)) {
RecordTypeLoc RecordTL = TLB.push<RecordTypeLoc>(T);
RecordTL.setNameLoc(IdInfo.IdentifierLoc);
} else if (isa<TypedefType>(T)) {
TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(T);
TypedefTL.setNameLoc(IdInfo.IdentifierLoc);
} else if (isa<EnumType>(T)) {
EnumTypeLoc EnumTL = TLB.push<EnumTypeLoc>(T);
EnumTL.setNameLoc(IdInfo.IdentifierLoc);
} else if (isa<TemplateTypeParmType>(T)) {
TemplateTypeParmTypeLoc TemplateTypeTL
= TLB.push<TemplateTypeParmTypeLoc>(T);
TemplateTypeTL.setNameLoc(IdInfo.IdentifierLoc);
} else if (isa<UnresolvedUsingType>(T)) {
UnresolvedUsingTypeLoc UnresolvedTL
= TLB.push<UnresolvedUsingTypeLoc>(T);
UnresolvedTL.setNameLoc(IdInfo.IdentifierLoc);
} else if (isa<SubstTemplateTypeParmType>(T)) {
SubstTemplateTypeParmTypeLoc TL
= TLB.push<SubstTemplateTypeParmTypeLoc>(T);
TL.setNameLoc(IdInfo.IdentifierLoc);
} else if (isa<SubstTemplateTypeParmPackType>(T)) {
SubstTemplateTypeParmPackTypeLoc TL
= TLB.push<SubstTemplateTypeParmPackTypeLoc>(T);
TL.setNameLoc(IdInfo.IdentifierLoc);
} else {
llvm_unreachable("Unhandled TypeDecl node in nested-name-specifier");
}
if (T->isEnumeralType())
Diag(IdInfo.IdentifierLoc, diag::warn_cxx98_compat_enum_nested_name_spec);
SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T),
IdInfo.CCLoc);
return false;
}
// Otherwise, we have an error case. If we don't want diagnostics, just
// return an error now.
if (ErrorRecoveryLookup)
return true;
// If we didn't find anything during our lookup, try again with
// ordinary name lookup, which can help us produce better error
// messages.
if (Found.empty()) {
Found.clear(LookupOrdinaryName);
LookupName(Found, S);
}
// In Microsoft mode, if we are within a templated function and we can't
// resolve Identifier, then extend the SS with Identifier. This will have
// the effect of resolving Identifier during template instantiation.
// The goal is to be able to resolve a function call whose
// nested-name-specifier is located inside a dependent base class.
// Example:
//
// class C {
// public:
// static void foo2() { }
// };
// template <class T> class A { public: typedef C D; };
//
// template <class T> class B : public A<T> {
// public:
// void foo() { D::foo2(); }
// };
if (getLangOpts().MSVCCompat) {
DeclContext *DC = LookupCtx ? LookupCtx : CurContext;
if (DC->isDependentContext() && DC->isFunctionOrMethod()) {
CXXRecordDecl *ContainingClass = dyn_cast<CXXRecordDecl>(DC->getParent());
if (ContainingClass && ContainingClass->hasAnyDependentBases()) {
Diag(IdInfo.IdentifierLoc,
diag::ext_undeclared_unqual_id_with_dependent_base)
<< IdInfo.Identifier << ContainingClass;
SS.Extend(Context, IdInfo.Identifier, IdInfo.IdentifierLoc,
IdInfo.CCLoc);
return false;
}
}
}
if (!Found.empty()) {
if (TypeDecl *TD = Found.getAsSingle<TypeDecl>())
Diag(IdInfo.IdentifierLoc, diag::err_expected_class_or_namespace)
<< Context.getTypeDeclType(TD) << getLangOpts().CPlusPlus;
else {
Diag(IdInfo.IdentifierLoc, diag::err_expected_class_or_namespace)
<< IdInfo.Identifier << getLangOpts().CPlusPlus;
if (NamedDecl *ND = Found.getAsSingle<NamedDecl>())
Diag(ND->getLocation(), diag::note_entity_declared_at)
<< IdInfo.Identifier;
}
} else if (SS.isSet())
Diag(IdInfo.IdentifierLoc, diag::err_no_member) << IdInfo.Identifier
<< LookupCtx << SS.getRange();
else
Diag(IdInfo.IdentifierLoc, diag::err_undeclared_var_use)
<< IdInfo.Identifier;
return true;
}
/// ActOnCXXNew - Parsed a C++ 'new' expression (C++ 5.3.4), as in e.g.:
/// @code new (memory) int[size][4] @endcode
/// or
/// @code ::new Foo(23, "hello") @endcode
/// For the interpretation of this heap of arguments, consult the base version.
Action::OwningExprResult
Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
SourceLocation PlacementLParen, MultiExprArg PlacementArgs,
SourceLocation PlacementRParen, bool ParenTypeId,
Declarator &D, SourceLocation ConstructorLParen,
MultiExprArg ConstructorArgs,
SourceLocation ConstructorRParen)
{
Expr *ArraySize = 0;
unsigned Skip = 0;
// If the specified type is an array, unwrap it and save the expression.
if (D.getNumTypeObjects() > 0 &&
D.getTypeObject(0).Kind == DeclaratorChunk::Array) {
DeclaratorChunk &Chunk = D.getTypeObject(0);
if (Chunk.Arr.hasStatic)
return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new)
<< D.getSourceRange());
if (!Chunk.Arr.NumElts)
return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size)
<< D.getSourceRange());
ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts);
Skip = 1;
}
QualType AllocType = GetTypeForDeclarator(D, /*Scope=*/0, Skip);
if (D.getInvalidType())
return ExprError();
if (CheckAllocatedType(AllocType, D))
return ExprError();
QualType ResultType = AllocType->isDependentType()
? Context.DependentTy
: Context.getPointerType(AllocType);
// That every array dimension except the first is constant was already
// checked by the type check above.
// C++ 5.3.4p6: "The expression in a direct-new-declarator shall have integral
// or enumeration type with a non-negative value."
if (ArraySize && !ArraySize->isTypeDependent()) {
QualType SizeType = ArraySize->getType();
if (!SizeType->isIntegralType() && !SizeType->isEnumeralType())
return ExprError(Diag(ArraySize->getSourceRange().getBegin(),
diag::err_array_size_not_integral)
<< SizeType << ArraySize->getSourceRange());
// Let's see if this is a constant < 0. If so, we reject it out of hand.
// We don't care about special rules, so we tell the machinery it's not
// evaluated - it gives us a result in more cases.
if (!ArraySize->isValueDependent()) {
llvm::APSInt Value;
if (ArraySize->isIntegerConstantExpr(Value, Context, 0, false)) {
if (Value < llvm::APSInt(
llvm::APInt::getNullValue(Value.getBitWidth()), false))
return ExprError(Diag(ArraySize->getSourceRange().getBegin(),
diag::err_typecheck_negative_array_size)
<< ArraySize->getSourceRange());
}
}
}
FunctionDecl *OperatorNew = 0;
FunctionDecl *OperatorDelete = 0;
Expr **PlaceArgs = (Expr**)PlacementArgs.get();
unsigned NumPlaceArgs = PlacementArgs.size();
if (!AllocType->isDependentType() &&
!Expr::hasAnyTypeDependentArguments(PlaceArgs, NumPlaceArgs) &&
FindAllocationFunctions(StartLoc,
SourceRange(PlacementLParen, PlacementRParen),
UseGlobal, AllocType, ArraySize, PlaceArgs,
NumPlaceArgs, OperatorNew, OperatorDelete))
return ExprError();
bool Init = ConstructorLParen.isValid();
// --- Choosing a constructor ---
// C++ 5.3.4p15
// 1) If T is a POD and there's no initializer (ConstructorLParen is invalid)
// the object is not initialized. If the object, or any part of it, is
// const-qualified, it's an error.
// 2) If T is a POD and there's an empty initializer, the object is value-
// initialized.
// 3) If T is a POD and there's one initializer argument, the object is copy-
// constructed.
// 4) If T is a POD and there's more initializer arguments, it's an error.
// 5) If T is not a POD, the initializer arguments are used as constructor
// arguments.
//
// Or by the C++0x formulation:
// 1) If there's no initializer, the object is default-initialized according
// to C++0x rules.
// 2) Otherwise, the object is direct-initialized.
CXXConstructorDecl *Constructor = 0;
Expr **ConsArgs = (Expr**)ConstructorArgs.get();
unsigned NumConsArgs = ConstructorArgs.size();
if (AllocType->isDependentType()) {
// Skip all the checks.
}
// FIXME: Should check for primitive/aggregate here, not record.
else if (const RecordType *RT = AllocType->getAsRecordType()) {
// FIXME: This is incorrect for when there is an empty initializer and
// no user-defined constructor. Must zero-initialize, not default-construct.
Constructor = PerformInitializationByConstructor(
AllocType, ConsArgs, NumConsArgs,
D.getSourceRange().getBegin(),
SourceRange(D.getSourceRange().getBegin(),
ConstructorRParen),
RT->getDecl()->getDeclName(),
NumConsArgs != 0 ? IK_Direct : IK_Default);
if (!Constructor)
return ExprError();
} else {
if (!Init) {
// FIXME: Check that no subpart is const.
if (AllocType.isConstQualified())
return ExprError(Diag(StartLoc, diag::err_new_uninitialized_const)
<< D.getSourceRange());
} else if (NumConsArgs == 0) {
// Object is value-initialized. Do nothing.
} else if (NumConsArgs == 1) {
// Object is direct-initialized.
// FIXME: WHAT DeclarationName do we pass in here?
if (CheckInitializerTypes(ConsArgs[0], AllocType, StartLoc,
DeclarationName() /*AllocType.getAsString()*/,
/*DirectInit=*/true))
return ExprError();
} else {
return ExprError(Diag(StartLoc,
diag::err_builtin_direct_init_more_than_one_arg)
<< SourceRange(ConstructorLParen, ConstructorRParen));
}
}
// FIXME: Also check that the destructor is accessible. (C++ 5.3.4p16)
PlacementArgs.release();
ConstructorArgs.release();
return Owned(new (Context) CXXNewExpr(UseGlobal, OperatorNew, PlaceArgs,
NumPlaceArgs, ParenTypeId, ArraySize, Constructor, Init,
ConsArgs, NumConsArgs, OperatorDelete, ResultType,
StartLoc, Init ? ConstructorRParen : SourceLocation()));
}
void AvoidCStyleCastsCheck::check(const MatchFinder::MatchResult &Result) {
const auto *CastExpr = Result.Nodes.getNodeAs<CStyleCastExpr>("cast");
auto ParenRange = CharSourceRange::getTokenRange(CastExpr->getLParenLoc(),
CastExpr->getRParenLoc());
// Ignore casts in macros.
if (ParenRange.getBegin().isMacroID() || ParenRange.getEnd().isMacroID())
return;
// Casting to void is an idiomatic way to mute "unused variable" and similar
// warnings.
if (CastExpr->getTypeAsWritten()->isVoidType())
return;
QualType SourceType =
CastExpr->getSubExprAsWritten()->getType().getCanonicalType();
QualType DestType = CastExpr->getTypeAsWritten().getCanonicalType();
if (SourceType == DestType) {
diag(CastExpr->getLocStart(), "Redundant cast to the same type.")
<< FixItHint::CreateRemoval(ParenRange);
return;
}
// The rest of this check is only relevant to C++.
if (!Result.Context->getLangOpts().CPlusPlus)
return;
// Leave type spelling exactly as it was (unlike
// getTypeAsWritten().getAsString() which would spell enum types 'enum X').
StringRef DestTypeString = Lexer::getSourceText(
CharSourceRange::getTokenRange(
CastExpr->getLParenLoc().getLocWithOffset(1),
CastExpr->getRParenLoc().getLocWithOffset(-1)),
*Result.SourceManager, Result.Context->getLangOpts());
auto diag_builder =
diag(CastExpr->getLocStart(), "C-style casts are discouraged. %0");
auto ReplaceWithCast = [&](StringRef CastType) {
diag_builder << ("Use " + CastType + ".").str();
const Expr *SubExpr = CastExpr->getSubExprAsWritten()->IgnoreImpCasts();
std::string CastText = (CastType + "<" + DestTypeString + ">").str();
if (!isa<ParenExpr>(SubExpr)) {
CastText.push_back('(');
diag_builder << FixItHint::CreateInsertion(
Lexer::getLocForEndOfToken(SubExpr->getLocEnd(), 0,
*Result.SourceManager,
Result.Context->getLangOpts()),
")");
}
diag_builder << FixItHint::CreateReplacement(ParenRange, CastText);
};
// Suggest appropriate C++ cast. See [expr.cast] for cast notation semantics.
switch (CastExpr->getCastKind()) {
case CK_NoOp:
if (needsConstCast(SourceType, DestType) &&
pointedTypesAreEqual(SourceType, DestType)) {
ReplaceWithCast("const_cast");
return;
}
if (DestType->isReferenceType() &&
(SourceType.getNonReferenceType() ==
DestType.getNonReferenceType().withConst() ||
SourceType.getNonReferenceType() == DestType.getNonReferenceType())) {
ReplaceWithCast("const_cast");
return;
}
// FALLTHROUGH
case clang::CK_IntegralCast:
// Convert integral and no-op casts between builtin types and enums to
// static_cast. A cast from enum to integer may be unnecessary, but it's
// still retained.
if ((SourceType->isBuiltinType() || SourceType->isEnumeralType()) &&
(DestType->isBuiltinType() || DestType->isEnumeralType())) {
ReplaceWithCast("static_cast");
return;
}
break;
case CK_BitCast:
// FIXME: Suggest const_cast<...>(reinterpret_cast<...>(...)) replacement.
if (!needsConstCast(SourceType, DestType)) {
ReplaceWithCast("reinterpret_cast");
return;
}
break;
default:
break;
}
diag_builder << "Use static_cast/const_cast/reinterpret_cast.";
}
/// CheckStaticCast - Check that a static_cast\<DestType\>(SrcExpr) is valid.
/// Refer to C++ 5.2.9 for details. Static casts are mostly used for making
/// implicit conversions explicit and getting rid of data loss warnings.
void
CheckStaticCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
const SourceRange &OpRange)
{
// The order the tests is not entirely arbitrary. There is one conversion
// that can be handled in two different ways. Given:
// struct A {};
// struct B : public A {
// B(); B(const A&);
// };
// const A &a = B();
// the cast static_cast<const B&>(a) could be seen as either a static
// reference downcast, or an explicit invocation of the user-defined
// conversion using B's conversion constructor.
// DR 427 specifies that the downcast is to be applied here.
// FIXME: With N2812, casts to rvalue refs will change.
// C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
if (DestType->isVoidType()) {
return;
}
// C++ 5.2.9p5, reference downcast.
// See the function for details.
// DR 427 specifies that this is to be applied before paragraph 2.
if (TryStaticReferenceDowncast(Self, SrcExpr, DestType, OpRange)
> TSC_NotApplicable) {
return;
}
// N2844 5.2.9p3: An lvalue of type "cv1 T1" can be cast to type "rvalue
// reference to cv2 T2" if "cv2 T2" is reference-compatible with "cv1 T1".
if (TryLValueToRValueCast(Self, SrcExpr, DestType, OpRange) >
TSC_NotApplicable) {
return;
}
// C++ 5.2.9p2: An expression e can be explicitly converted to a type T
// [...] if the declaration "T t(e);" is well-formed, [...].
if (TryStaticImplicitCast(Self, SrcExpr, DestType, OpRange) >
TSC_NotApplicable) {
return;
}
// C++ 5.2.9p6: May apply the reverse of any standard conversion, except
// lvalue-to-rvalue, array-to-pointer, function-to-pointer, and boolean
// conversions, subject to further restrictions.
// Also, C++ 5.2.9p1 forbids casting away constness, which makes reversal
// of qualification conversions impossible.
// The lvalue-to-rvalue, array-to-pointer and function-to-pointer conversions
// are applied to the expression.
QualType OrigSrcType = SrcExpr->getType();
Self.DefaultFunctionArrayConversion(SrcExpr);
QualType SrcType = Self.Context.getCanonicalType(SrcExpr->getType());
// Reverse integral promotion/conversion. All such conversions are themselves
// again integral promotions or conversions and are thus already handled by
// p2 (TryDirectInitialization above).
// (Note: any data loss warnings should be suppressed.)
// The exception is the reverse of enum->integer, i.e. integer->enum (and
// enum->enum). See also C++ 5.2.9p7.
// The same goes for reverse floating point promotion/conversion and
// floating-integral conversions. Again, only floating->enum is relevant.
if (DestType->isEnumeralType()) {
if (SrcType->isComplexType() || SrcType->isVectorType()) {
// Fall through - these cannot be converted.
} else if (SrcType->isArithmeticType() || SrcType->isEnumeralType()) {
return;
}
}
// Reverse pointer upcast. C++ 4.10p3 specifies pointer upcast.
// C++ 5.2.9p8 additionally disallows a cast path through virtual inheritance.
if (TryStaticPointerDowncast(Self, SrcType, DestType, OpRange)
> TSC_NotApplicable) {
return;
}
// Reverse member pointer conversion. C++ 4.11 specifies member pointer
// conversion. C++ 5.2.9p9 has additional information.
// DR54's access restrictions apply here also.
if (TryStaticMemberPointerUpcast(Self, SrcType, DestType, OpRange)
> TSC_NotApplicable) {
return;
}
// Reverse pointer conversion to void*. C++ 4.10.p2 specifies conversion to
// void*. C++ 5.2.9p10 specifies additional restrictions, which really is
// just the usual constness stuff.
if (const PointerType *SrcPointer = SrcType->getAsPointerType()) {
QualType SrcPointee = SrcPointer->getPointeeType();
if (SrcPointee->isVoidType()) {
if (const PointerType *DestPointer = DestType->getAsPointerType()) {
QualType DestPointee = DestPointer->getPointeeType();
if (DestPointee->isIncompleteOrObjectType()) {
// This is definitely the intended conversion, but it might fail due
// to a const violation.
if (!DestPointee.isAtLeastAsQualifiedAs(SrcPointee)) {
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away)
<< "static_cast" << DestType << OrigSrcType << OpRange;
}
return;
}
}
}
}
// We tried everything. Everything! Nothing works! :-(
// FIXME: Error reporting could be a lot better. Should store the reason why
// every substep failed and, at the end, select the most specific and report
// that.
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
<< "static_cast" << DestType << OrigSrcType
<< OpRange;
}
/// CheckReinterpretCast - Check that a reinterpret_cast\<DestType\>(SrcExpr) is
/// valid.
/// Refer to C++ 5.2.10 for details. reinterpret_cast is typically used in code
/// like this:
/// char *bytes = reinterpret_cast\<char*\>(int_ptr);
void
CheckReinterpretCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
const SourceRange &OpRange, const SourceRange &DestRange)
{
QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
DestType = Self.Context.getCanonicalType(DestType);
QualType SrcType = SrcExpr->getType();
if (const LValueReferenceType *DestTypeTmp =
DestType->getAsLValueReferenceType()) {
if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
// Cannot cast non-lvalue to reference type.
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue)
<< "reinterpret_cast" << OrigDestType << SrcExpr->getSourceRange();
return;
}
// C++ 5.2.10p10: [...] a reference cast reinterpret_cast<T&>(x) has the
// same effect as the conversion *reinterpret_cast<T*>(&x) with the
// built-in & and * operators.
// This code does this transformation for the checked types.
DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
SrcType = Self.Context.getPointerType(SrcType);
} else if (const RValueReferenceType *DestTypeTmp =
DestType->getAsRValueReferenceType()) {
// Both the reference conversion and the rvalue rules apply.
Self.DefaultFunctionArrayConversion(SrcExpr);
SrcType = SrcExpr->getType();
DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
SrcType = Self.Context.getPointerType(SrcType);
} else {
// C++ 5.2.10p1: [...] the lvalue-to-rvalue, array-to-pointer, and
// function-to-pointer standard conversions are performed on the
// expression v.
Self.DefaultFunctionArrayConversion(SrcExpr);
SrcType = SrcExpr->getType();
}
// Canonicalize source for comparison.
SrcType = Self.Context.getCanonicalType(SrcType);
const MemberPointerType *DestMemPtr = DestType->getAsMemberPointerType(),
*SrcMemPtr = SrcType->getAsMemberPointerType();
if (DestMemPtr && SrcMemPtr) {
// C++ 5.2.10p9: An rvalue of type "pointer to member of X of type T1"
// can be explicitly converted to an rvalue of type "pointer to member
// of Y of type T2" if T1 and T2 are both function types or both object
// types.
if (DestMemPtr->getPointeeType()->isFunctionType() !=
SrcMemPtr->getPointeeType()->isFunctionType()) {
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
<< "reinterpret_cast" << OrigDestType << OrigSrcType << OpRange;
return;
}
// C++ 5.2.10p2: The reinterpret_cast operator shall not cast away
// constness.
if (CastsAwayConstness(Self, SrcType, DestType)) {
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away)
<< "reinterpret_cast" << OrigDestType << OrigSrcType << OpRange;
return;
}
// A valid member pointer cast.
return;
}
// See below for the enumeral issue.
if (SrcType->isNullPtrType() && DestType->isIntegralType() &&
!DestType->isEnumeralType()) {
// C++0x 5.2.10p4: A pointer can be explicitly converted to any integral
// type large enough to hold it. A value of std::nullptr_t can be
// converted to an integral type; the conversion has the same meaning
// and validity as a conversion of (void*)0 to the integral type.
if (Self.Context.getTypeSize(SrcType) >
Self.Context.getTypeSize(DestType)) {
Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_small_int)
<< OrigDestType << DestRange;
}
return;
}
bool destIsPtr = DestType->isPointerType();
bool srcIsPtr = SrcType->isPointerType();
if (!destIsPtr && !srcIsPtr) {
// Except for std::nullptr_t->integer and lvalue->reference, which are
// handled above, at least one of the two arguments must be a pointer.
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
<< "reinterpret_cast" << OrigDestType << OrigSrcType << OpRange;
return;
}
if (SrcType == DestType) {
// C++ 5.2.10p2 has a note that mentions that, subject to all other
// restrictions, a cast to the same type is allowed. The intent is not
// entirely clear here, since all other paragraphs explicitly forbid casts
// to the same type. However, the behavior of compilers is pretty consistent
// on this point: allow same-type conversion if the involved types are
// pointers, disallow otherwise.
return;
}
// Note: Clang treats enumeration types as integral types. If this is ever
// changed for C++, the additional check here will be redundant.
if (DestType->isIntegralType() && !DestType->isEnumeralType()) {
assert(srcIsPtr && "One type must be a pointer");
// C++ 5.2.10p4: A pointer can be explicitly converted to any integral
// type large enough to hold it.
if (Self.Context.getTypeSize(SrcType) >
Self.Context.getTypeSize(DestType)) {
Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_small_int)
<< OrigDestType << DestRange;
}
return;
}
if (SrcType->isIntegralType() || SrcType->isEnumeralType()) {
assert(destIsPtr && "One type must be a pointer");
// C++ 5.2.10p5: A value of integral or enumeration type can be explicitly
// converted to a pointer.
return;
}
if (!destIsPtr || !srcIsPtr) {
// With the valid non-pointer conversions out of the way, we can be even
// more stringent.
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
<< "reinterpret_cast" << OrigDestType << OrigSrcType << OpRange;
return;
}
// C++ 5.2.10p2: The reinterpret_cast operator shall not cast away constness.
if (CastsAwayConstness(Self, SrcType, DestType)) {
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away)
<< "reinterpret_cast" << OrigDestType << OrigSrcType << OpRange;
return;
}
// Not casting away constness, so the only remaining check is for compatible
// pointer categories.
if (SrcType->isFunctionPointerType()) {
if (DestType->isFunctionPointerType()) {
// C++ 5.2.10p6: A pointer to a function can be explicitly converted to
// a pointer to a function of a different type.
return;
}
// C++0x 5.2.10p8: Converting a pointer to a function into a pointer to
// an object type or vice versa is conditionally-supported.
// Compilers support it in C++03 too, though, because it's necessary for
// casting the return value of dlsym() and GetProcAddress().
// FIXME: Conditionally-supported behavior should be configurable in the
// TargetInfo or similar.
if (!Self.getLangOptions().CPlusPlus0x) {
Self.Diag(OpRange.getBegin(), diag::ext_reinterpret_cast_fn_obj)
<< OpRange;
}
return;
}
if (DestType->isFunctionPointerType()) {
// See above.
if (!Self.getLangOptions().CPlusPlus0x) {
Self.Diag(OpRange.getBegin(), diag::ext_reinterpret_cast_fn_obj)
<< OpRange;
}
return;
}
// C++ 5.2.10p7: A pointer to an object can be explicitly converted to
// a pointer to an object of different type.
// Void pointers are not specified, but supported by every compiler out there.
// So we finish by allowing everything that remains - it's got to be two
// object pointers.
}
void AvoidCStyleCastsCheck::check(const MatchFinder::MatchResult &Result) {
const auto *CastExpr = Result.Nodes.getNodeAs<CStyleCastExpr>("cast");
// Ignore casts in macros.
if (CastExpr->getExprLoc().isMacroID())
return;
// Casting to void is an idiomatic way to mute "unused variable" and similar
// warnings.
if (CastExpr->getCastKind() == CK_ToVoid)
return;
auto isFunction = [](QualType T) {
T = T.getCanonicalType().getNonReferenceType();
return T->isFunctionType() || T->isFunctionPointerType() ||
T->isMemberFunctionPointerType();
};
const QualType DestTypeAsWritten =
CastExpr->getTypeAsWritten().getUnqualifiedType();
const QualType SourceTypeAsWritten =
CastExpr->getSubExprAsWritten()->getType().getUnqualifiedType();
const QualType SourceType = SourceTypeAsWritten.getCanonicalType();
const QualType DestType = DestTypeAsWritten.getCanonicalType();
auto ReplaceRange = CharSourceRange::getCharRange(
CastExpr->getLParenLoc(), CastExpr->getSubExprAsWritten()->getBeginLoc());
bool FnToFnCast =
isFunction(SourceTypeAsWritten) && isFunction(DestTypeAsWritten);
if (CastExpr->getCastKind() == CK_NoOp && !FnToFnCast) {
// Function pointer/reference casts may be needed to resolve ambiguities in
// case of overloaded functions, so detection of redundant casts is trickier
// in this case. Don't emit "redundant cast" warnings for function
// pointer/reference types.
if (SourceTypeAsWritten == DestTypeAsWritten) {
diag(CastExpr->getBeginLoc(), "redundant cast to the same type")
<< FixItHint::CreateRemoval(ReplaceRange);
return;
}
}
// The rest of this check is only relevant to C++.
// We also disable it for Objective-C++.
if (!getLangOpts().CPlusPlus || getLangOpts().ObjC1 || getLangOpts().ObjC2)
return;
// Ignore code inside extern "C" {} blocks.
if (!match(expr(hasAncestor(linkageSpecDecl())), *CastExpr, *Result.Context)
.empty())
return;
// Ignore code in .c files and headers included from them, even if they are
// compiled as C++.
if (getCurrentMainFile().endswith(".c"))
return;
SourceManager &SM = *Result.SourceManager;
// Ignore code in .c files #included in other files (which shouldn't be done,
// but people still do this for test and other purposes).
if (SM.getFilename(SM.getSpellingLoc(CastExpr->getBeginLoc())).endswith(".c"))
return;
// Leave type spelling exactly as it was (unlike
// getTypeAsWritten().getAsString() which would spell enum types 'enum X').
StringRef DestTypeString =
Lexer::getSourceText(CharSourceRange::getTokenRange(
CastExpr->getLParenLoc().getLocWithOffset(1),
CastExpr->getRParenLoc().getLocWithOffset(-1)),
SM, getLangOpts());
auto Diag =
diag(CastExpr->getBeginLoc(), "C-style casts are discouraged; use %0");
auto ReplaceWithCast = [&](std::string CastText) {
const Expr *SubExpr = CastExpr->getSubExprAsWritten()->IgnoreImpCasts();
if (!isa<ParenExpr>(SubExpr)) {
CastText.push_back('(');
Diag << FixItHint::CreateInsertion(
Lexer::getLocForEndOfToken(SubExpr->getEndLoc(), 0, SM,
getLangOpts()),
")");
}
Diag << FixItHint::CreateReplacement(ReplaceRange, CastText);
};
auto ReplaceWithNamedCast = [&](StringRef CastType) {
Diag << CastType;
ReplaceWithCast((CastType + "<" + DestTypeString + ">").str());
};
// Suggest appropriate C++ cast. See [expr.cast] for cast notation semantics.
switch (CastExpr->getCastKind()) {
case CK_FunctionToPointerDecay:
ReplaceWithNamedCast("static_cast");
return;
case CK_ConstructorConversion:
if (!CastExpr->getTypeAsWritten().hasQualifiers() &&
DestTypeAsWritten->isRecordType() &&
!DestTypeAsWritten->isElaboratedTypeSpecifier()) {
Diag << "constructor call syntax";
// FIXME: Validate DestTypeString, maybe.
ReplaceWithCast(DestTypeString.str());
} else {
ReplaceWithNamedCast("static_cast");
}
return;
case CK_NoOp:
if (FnToFnCast) {
ReplaceWithNamedCast("static_cast");
return;
}
if (SourceType == DestType) {
Diag << "static_cast (if needed, the cast may be redundant)";
ReplaceWithCast(("static_cast<" + DestTypeString + ">").str());
return;
}
if (needsConstCast(SourceType, DestType) &&
pointedUnqualifiedTypesAreEqual(SourceType, DestType)) {
ReplaceWithNamedCast("const_cast");
return;
}
if (DestType->isReferenceType()) {
QualType Dest = DestType.getNonReferenceType();
QualType Source = SourceType.getNonReferenceType();
if (Source == Dest.withConst() ||
SourceType.getNonReferenceType() == DestType.getNonReferenceType()) {
ReplaceWithNamedCast("const_cast");
return;
}
break;
}
// FALLTHROUGH
case clang::CK_IntegralCast:
// Convert integral and no-op casts between builtin types and enums to
// static_cast. A cast from enum to integer may be unnecessary, but it's
// still retained.
if ((SourceType->isBuiltinType() || SourceType->isEnumeralType()) &&
(DestType->isBuiltinType() || DestType->isEnumeralType())) {
ReplaceWithNamedCast("static_cast");
return;
}
break;
case CK_BitCast:
// FIXME: Suggest const_cast<...>(reinterpret_cast<...>(...)) replacement.
if (!needsConstCast(SourceType, DestType)) {
if (SourceType->isVoidPointerType())
ReplaceWithNamedCast("static_cast");
else
ReplaceWithNamedCast("reinterpret_cast");
return;
}
break;
default:
break;
}
Diag << "static_cast/const_cast/reinterpret_cast";
}