Unify the code for defining tags in C and C++, so that we always
introduce a Scope for the body of a tag. This reduces the number of
semantic differences between C and C++ structs and unions, and will
help with other features (e.g., anonymous unions) in C. Some important
points:
- Fields are now in the "member" namespace (IDNS_Member), to keep
them separate from tags and ordinary names in C. See the new test
in Sema/member-reference.c for an example of why this matters. In
C++, ordinary and member name lookup will find members in both the
ordinary and member namespace, so the difference between
IDNS_Member and IDNS_Ordinary is erased by Sema::LookupDecl (but
only in C++!).
- We always introduce a Scope and push a DeclContext when we're
defining a tag, in both C and C++. Previously, we had different
actions and different Scope/CurContext behavior for enums, C
structs/unions, and C++ structs/unions/classes. Now, it's one pair
of actions. (Yay!)
There's still some fuzziness in the handling of struct/union/enum
definitions within other struct/union/enum definitions in C. We'll
need to do some more cleanup to eliminate some reliance on CurContext
before we can solve this issue for real. What we want is for something
like this:
struct X {
struct T { int x; } t;
};
to introduce T into translation unit scope (placing it at the
appropriate point in the IdentifierResolver chain, too), but it should
still have struct X as its lexical declaration
context. PushOnScopeChains isn't smart enough to do that yet, though,
so there's a FIXME test in nested-redef.c
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@61940 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 6585733..c6e4336 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -263,18 +263,37 @@
bool NamespaceNameOnly) {
if (!Name) return 0;
unsigned NS = NSI;
- if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary))
- NS |= Decl::IDNS_Tag;
- if (LookupCtx == 0 &&
- (!getLangOptions().CPlusPlus || (NS == Decl::IDNS_Label))) {
- // Unqualified name lookup in C/Objective-C and name lookup for
- // labels in C++ is purely lexical, so search in the
- // declarations attached to the name.
+ // In C++, ordinary and member lookup will always find all
+ // kinds of names.
+ if (getLangOptions().CPlusPlus &&
+ (NS & (Decl::IDNS_Ordinary | Decl::IDNS_Member)))
+ NS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Ordinary;
+
+ if (LookupCtx == 0 && !getLangOptions().CPlusPlus) {
+ // Unqualified name lookup in C/Objective-C is purely lexical, so
+ // search in the declarations attached to the name.
assert(!LookupCtx && "Can't perform qualified name lookup here");
assert(!NamespaceNameOnly && "Can't perform namespace name lookup here");
+
+ // For the purposes of unqualified name lookup, structs and unions
+ // don't have scopes at all. For example:
+ //
+ // struct X {
+ // struct T { int i; } x;
+ // };
+ //
+ // void f() {
+ // struct T t; // okay: T is defined lexically within X, but
+ // // semantically at global scope
+ // };
+ //
+ // FIXME: Is there a better way to deal with this?
+ DeclContext *SearchCtx = CurContext;
+ while (isa<RecordDecl>(SearchCtx) || isa<EnumDecl>(SearchCtx))
+ SearchCtx = SearchCtx->getParent();
IdentifierResolver::iterator I
- = IdResolver.begin(Name, CurContext, LookInParent);
+ = IdResolver.begin(Name, SearchCtx, LookInParent);
// Scan up the scope chain looking for a decl that matches this
// identifier that is in the appropriate namespace. This search
@@ -284,6 +303,11 @@
if ((*I)->isInIdentifierNamespace(NS))
return *I;
} else if (LookupCtx) {
+ // If we're performing qualified name lookup (e.g., lookup into a
+ // struct), find fields as part of ordinary name lookup.
+ if (NS & Decl::IDNS_Ordinary)
+ NS |= Decl::IDNS_Member;
+
// Perform qualified name lookup into the LookupCtx.
// FIXME: Will need to look into base classes and such.
DeclContext::lookup_const_iterator I, E;
@@ -2852,6 +2876,15 @@
// declaration or definition.
// Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up.
PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S));
+
+ if (!getLangOptions().CPlusPlus && TK != TK_Reference) {
+ // FIXME: This makes sure that we ignore the contexts associated
+ // with C structs, unions, and enums when looking for a matching
+ // tag declaration or definition. See the similar lookup tweak
+ // in Sema::LookupDecl; is there a better way to deal with this?
+ while (isa<RecordDecl>(DC) || isa<EnumDecl>(DC))
+ DC = DC->getParent();
+ }
}
if (PrevDecl && PrevDecl->isTemplateParameter()) {
@@ -3007,6 +3040,43 @@
return New;
}
+void Sema::ActOnTagStartDefinition(Scope *S, DeclTy *TagD) {
+ TagDecl *Tag = cast<TagDecl>((Decl *)TagD);
+
+ // Enter the tag context.
+ PushDeclContext(S, Tag);
+
+ if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Tag)) {
+ FieldCollector->StartClass();
+
+ if (Record->getIdentifier()) {
+ // C++ [class]p2:
+ // [...] The class-name is also inserted into the scope of the
+ // class itself; this is known as the injected-class-name. For
+ // purposes of access checking, the injected-class-name is treated
+ // as if it were a public member name.
+ RecordDecl *InjectedClassName
+ = CXXRecordDecl::Create(Context, Record->getTagKind(),
+ CurContext, Record->getLocation(),
+ Record->getIdentifier(), Record);
+ InjectedClassName->setImplicit();
+ PushOnScopeChains(InjectedClassName, S);
+ }
+ }
+}
+
+void Sema::ActOnTagFinishDefinition(Scope *S, DeclTy *TagD) {
+ TagDecl *Tag = cast<TagDecl>((Decl *)TagD);
+
+ if (isa<CXXRecordDecl>(Tag))
+ FieldCollector->FinishClass();
+
+ // Exit this scope of this tag's definition.
+ PopDeclContext();
+
+ // Notify the consumer that we've defined a tag.
+ Consumer.HandleTagDeclDefinition(Tag);
+}
/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array
/// types into constant array types in certain situations which would otherwise
@@ -3108,6 +3178,18 @@
DeclSpec::SCS_mutable,
/*PrevDecl=*/0);
+ if (II) {
+ Decl *PrevDecl
+ = LookupDecl(II, Decl::IDNS_Member, S, 0, false, false, false);
+ if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S)
+ && !isa<TagDecl>(PrevDecl)) {
+ Diag(Loc, diag::err_duplicate_member) << II;
+ Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
+ NewFD->setInvalidDecl();
+ Record->setInvalidDecl();
+ }
+ }
+
if (getLangOptions().CPlusPlus) {
CheckExtraCXXDefaultArguments(D);
if (!T->isPODType())
@@ -3119,9 +3201,9 @@
if (D.getInvalidType() || InvalidDecl)
NewFD->setInvalidDecl();
- if (II && getLangOptions().CPlusPlus)
+ if (II) {
PushOnScopeChains(NewFD, S);
- else
+ } else
Record->addDecl(Context, NewFD);
return NewFD;
@@ -3146,6 +3228,7 @@
SourceLocation DeclStart,
Declarator &D, ExprTy *BitfieldWidth,
tok::ObjCKeywordKind Visibility) {
+
IdentifierInfo *II = D.getIdentifier();
Expr *BitWidth = (Expr*)BitfieldWidth;
SourceLocation Loc = DeclStart;
@@ -3188,12 +3271,30 @@
ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac,
(Expr *)BitfieldWidth);
+ if (II) {
+ Decl *PrevDecl
+ = LookupDecl(II, Decl::IDNS_Member, S, 0, false, false, false);
+ if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S)
+ && !isa<TagDecl>(PrevDecl)) {
+ Diag(Loc, diag::err_duplicate_member) << II;
+ Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
+ NewID->setInvalidDecl();
+ }
+ }
+
// Process attributes attached to the ivar.
ProcessDeclAttributes(NewID, D);
if (D.getInvalidType() || InvalidDecl)
NewID->setInvalidDecl();
+ if (II) {
+ // FIXME: When interfaces are DeclContexts, we'll need to add
+ // these to the interface.
+ S->AddDecl(NewID);
+ IdResolver.AddDecl(NewID);
+ }
+
return NewID;
}
@@ -3206,27 +3307,26 @@
assert(EnclosingDecl && "missing record or interface decl");
RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl);
- if (Record)
- if (RecordDecl* DefRecord = Record->getDefinition(Context)) {
+ if (Record) {
+ QualType RecordType = Context.getTypeDeclType(Record);
+ if (RecordType->getAsRecordType()->getDecl()->isDefinition()) {
+ RecordDecl *Def = RecordType->getAsRecordType()->getDecl();
// Diagnose code like:
// struct S { struct S {} X; };
// We discover this when we complete the outer S. Reject and ignore the
// outer S.
- Diag(DefRecord->getLocation(), diag::err_nested_redefinition)
- << DefRecord->getDeclName();
+ Diag(Def->getLocation(), diag::err_nested_redefinition)
+ << Def->getDeclName();
Diag(RecLoc, diag::note_previous_definition);
Record->setInvalidDecl();
return;
}
+ }
// Verify that all the fields are okay.
unsigned NumNamedMembers = 0;
llvm::SmallVector<FieldDecl*, 32> RecFields;
- // FIXME: Eventually, we'd like to eliminate this in favor of
- // checking for redeclarations on-the-fly.
- llvm::DenseMap<const IdentifierInfo*, FieldDecl *> FieldIDs;
-
for (unsigned i = 0; i != NumFields; ++i) {
FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i]));
assert(FD && "missing field decl");
@@ -3234,37 +3334,7 @@
// Get the type for the field.
Type *FDTy = FD->getType().getTypePtr();
- if (FD->isAnonymousStructOrUnion()) {
- // We have found a field that represents an anonymous struct
- // or union. Introduce all of the inner fields (recursively)
- // into the list of fields we know about, so that we can produce
- // an appropriate error message in cases like:
- //
- // struct X {
- // union {
- // int x;
- // float f;
- // };
- // double x;
- // };
- llvm::SmallVector<FieldDecl *, 4> AnonStructUnionFields;
- AnonStructUnionFields.push_back(FD);
- while (!AnonStructUnionFields.empty()) {
- FieldDecl *AnonField = AnonStructUnionFields.back();
- AnonStructUnionFields.pop_back();
-
- RecordDecl *AnonRecord
- = AnonField->getType()->getAsRecordType()->getDecl();
- for (RecordDecl::field_iterator F = AnonRecord->field_begin(),
- FEnd = AnonRecord->field_end();
- F != FEnd; ++F) {
- if ((*F)->isAnonymousStructOrUnion())
- AnonStructUnionFields.push_back(*F);
- else if (const IdentifierInfo *II = (*F)->getIdentifier())
- FieldIDs[II] = *F;
- }
- }
- } else {
+ if (!FD->isAnonymousStructOrUnion()) {
// Remember all fields written by the user.
RecFields.push_back(FD);
}
@@ -3340,28 +3410,13 @@
continue;
}
// Keep track of the number of named members.
- if (IdentifierInfo *II = FD->getIdentifier()) {
- // Detect duplicate member names.
- if (FieldIDs[II]) {
- Diag(FD->getLocation(), diag::err_duplicate_member) << II;
- // Find the previous decl.
- Diag(FieldIDs[II]->getLocation(), diag::note_previous_definition);
- FD->setInvalidDecl();
- EnclosingDecl->setInvalidDecl();
- continue;
- }
+ if (FD->getIdentifier())
++NumNamedMembers;
- FieldIDs[II] = FD;
- }
}
// Okay, we successfully defined 'Record'.
if (Record) {
Record->completeDefinition(Context);
- // If this is a C++ record, HandleTagDeclDefinition will be invoked in
- // Sema::ActOnFinishCXXClassDef.
- if (!isa<CXXRecordDecl>(Record))
- Consumer.HandleTagDeclDefinition(Record);
} else {
ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]);
if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) {
@@ -3376,7 +3431,7 @@
ObjCIvarDecl* prevIvar = ID->getSuperClass()->FindIvarDeclaration(II);
if (prevIvar) {
Diag(Ivar->getLocation(), diag::err_duplicate_member) << II;
- Diag(prevIvar->getLocation(), diag::note_previous_definition);
+ Diag(prevIvar->getLocation(), diag::note_previous_declaration);
}
}
}
@@ -3393,13 +3448,6 @@
ProcessDeclAttributeList(Record, Attr);
}
-void Sema::ActOnEnumStartDefinition(Scope *S, DeclTy *EnumD) {
- EnumDecl *Enum = cast<EnumDecl>((Decl *)EnumD);
-
- // Enter the enumeration context.
- PushDeclContext(S, Enum);
-}
-
Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl,
DeclTy *lastEnumConst,
SourceLocation IdLoc, IdentifierInfo *Id,
@@ -3507,7 +3555,6 @@
<< Enum->getDeclName();
Diag(Enum->getLocation(), diag::note_previous_definition);
Enum->setInvalidDecl();
- PopDeclContext();
return;
}
@@ -3675,10 +3722,6 @@
}
Enum->completeDefinition(Context, BestType);
- Consumer.HandleTagDeclDefinition(Enum);
-
- // Leave the context of the enumeration.
- PopDeclContext();
}
Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc,