Recommit my change to how C++ does elaborated type lookups, now with
two bugfixes which fix selfhost and (hopefully) the nightly tests.
llvm-svn: 102198
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index e71f8c8..35bb697 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -415,6 +415,9 @@
return false;
}
+
+ if (Filter == &ResultBuilder::IsNestedNameSpecifier)
+ AsNestedNameSpecifier = true;
// ... then it must be interesting!
return true;
@@ -504,7 +507,7 @@
}
for (; I != IEnd; ++I) {
// A tag declaration does not hide a non-tag declaration.
- if (I->first->getIdentifierNamespace() == Decl::IDNS_Tag &&
+ if (I->first->hasTagIdentifierNamespace() &&
(IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
Decl::IDNS_ObjCProtocol)))
continue;
@@ -629,7 +632,7 @@
bool ResultBuilder::IsOrdinaryName(NamedDecl *ND) const {
unsigned IDNS = Decl::IDNS_Ordinary;
if (SemaRef.getLangOptions().CPlusPlus)
- IDNS |= Decl::IDNS_Tag;
+ IDNS |= Decl::IDNS_Tag | Decl::IDNS_Namespace;
else if (SemaRef.getLangOptions().ObjC1 && isa<ObjCIvarDecl>(ND))
return true;
@@ -641,7 +644,7 @@
bool ResultBuilder::IsOrdinaryNonValueName(NamedDecl *ND) const {
unsigned IDNS = Decl::IDNS_Ordinary;
if (SemaRef.getLangOptions().CPlusPlus)
- IDNS |= Decl::IDNS_Tag;
+ IDNS |= Decl::IDNS_Tag | Decl::IDNS_Namespace;
return (ND->getIdentifierNamespace() & IDNS) &&
!isa<ValueDecl>(ND) && !isa<FunctionTemplateDecl>(ND);
@@ -2094,10 +2097,16 @@
return;
}
- ResultBuilder Results(*this, Filter);
- Results.allowNestedNameSpecifiers();
+ ResultBuilder Results(*this);
CodeCompletionDeclConsumer Consumer(Results, CurContext);
+
+ // First pass: look for tags.
+ Results.setFilter(Filter);
LookupVisibleDecls(S, LookupTagName, Consumer);
+
+ // Second pass: look for nested name specifiers.
+ Results.setFilter(&ResultBuilder::IsNestedNameSpecifier);
+ LookupVisibleDecls(S, LookupNestedNameSpecifierName, Consumer);
HandleCodeCompleteResults(this, CodeCompleter, Results.data(),Results.size());
}
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index c9001f1..cc57bdd 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -5000,7 +5000,8 @@
SearchDC = SearchDC->getEnclosingNamespaceContext();
}
- // In C++, look for a shadow friend decl.
+ // In C++, we need to do a redeclaration lookup to properly
+ // diagnose some problems.
if (getLangOptions().CPlusPlus) {
Previous.setRedeclarationKind(ForRedeclaration);
LookupQualifiedName(Previous, SearchDC);
@@ -5009,6 +5010,30 @@
if (!Previous.empty()) {
NamedDecl *PrevDecl = (*Previous.begin())->getUnderlyingDecl();
+
+ // It's okay to have a tag decl in the same scope as a typedef
+ // which hides a tag decl in the same scope. Finding this
+ // insanity with a redeclaration lookup can only actually happen
+ // in C++.
+ //
+ // This is also okay for elaborated-type-specifiers, which is
+ // technically forbidden by the current standard but which is
+ // okay according to the likely resolution of an open issue;
+ // see http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#407
+ if (getLangOptions().CPlusPlus) {
+ if (TypedefDecl *TD = dyn_cast<TypedefDecl>(PrevDecl)) {
+ if (const TagType *TT = TD->getUnderlyingType()->getAs<TagType>()) {
+ TagDecl *Tag = TT->getDecl();
+ if (Tag->getDeclName() == Name &&
+ Tag->getDeclContext()->Equals(TD->getDeclContext())) {
+ PrevDecl = Tag;
+ Previous.clear();
+ Previous.addDecl(Tag);
+ }
+ }
+ }
+ }
+
if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) {
// If this is a use of a previous tag, or if the tag is already declared
// in the same scope (so that the definition/declaration completes or
@@ -5100,23 +5125,61 @@
// If we get here, we're going to create a new Decl. If PrevDecl
// is non-NULL, it's a definition of the tag declared by
// PrevDecl. If it's NULL, we have a new definition.
+
+
+ // Otherwise, PrevDecl is not a tag, but was found with tag
+ // lookup. This is only actually possible in C++, where a few
+ // things like templates still live in the tag namespace.
} else {
- // PrevDecl is a namespace, template, or anything else
- // that lives in the IDNS_Tag identifier namespace.
- if (TUK == TUK_Reference || TUK == TUK_Friend ||
- isDeclInScope(PrevDecl, SearchDC, S)) {
- // The tag name clashes with a namespace name, issue an error and
- // recover by making this tag be anonymous.
+ assert(getLangOptions().CPlusPlus);
+
+ // Use a better diagnostic if an elaborated-type-specifier
+ // found the wrong kind of type on the first
+ // (non-redeclaration) lookup.
+ if ((TUK == TUK_Reference || TUK == TUK_Friend) &&
+ !Previous.isForRedeclaration()) {
+ unsigned Kind = 0;
+ if (isa<TypedefDecl>(PrevDecl)) Kind = 1;
+ else if (isa<ClassTemplateDecl>(PrevDecl)) Kind = 2;
+ Diag(NameLoc, diag::err_tag_reference_non_tag) << Kind;
+ Diag(PrevDecl->getLocation(), diag::note_declared_at);
+ Invalid = true;
+
+ // Otherwise, only diagnose if the declaration is in scope.
+ } else if (!isDeclInScope(PrevDecl, SearchDC, S)) {
+ // do nothing
+
+ // Diagnose implicit declarations introduced by elaborated types.
+ } else if (TUK == TUK_Reference || TUK == TUK_Friend) {
+ unsigned Kind = 0;
+ if (isa<TypedefDecl>(PrevDecl)) Kind = 1;
+ else if (isa<ClassTemplateDecl>(PrevDecl)) Kind = 2;
+ Diag(NameLoc, diag::err_tag_reference_conflict) << Kind;
+ Diag(PrevDecl->getLocation(), diag::note_previous_decl) << PrevDecl;
+ Invalid = true;
+
+ // Otherwise it's a declaration. Call out a particularly common
+ // case here.
+ } else if (isa<TypedefDecl>(PrevDecl)) {
+ Diag(NameLoc, diag::err_tag_definition_of_typedef)
+ << Name
+ << cast<TypedefDecl>(PrevDecl)->getUnderlyingType();
+ Diag(PrevDecl->getLocation(), diag::note_previous_decl) << PrevDecl;
+ Invalid = true;
+
+ // Otherwise, diagnose.
+ } else {
+ // The tag name clashes with something else in the target scope,
+ // issue an error and recover by making this tag be anonymous.
Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
Diag(PrevDecl->getLocation(), diag::note_previous_definition);
Name = 0;
- Previous.clear();
Invalid = true;
- } else {
- // The existing declaration isn't relevant to us; we're in a
- // new scope, so clear out the previous declaration.
- Previous.clear();
}
+
+ // The existing declaration isn't relevant to us; we're in a
+ // new scope, so clear out the previous declaration.
+ Previous.clear();
}
}
@@ -5187,28 +5250,6 @@
New->addAttr(::new (Context) PragmaPackAttr(Alignment * 8));
}
- if (getLangOptions().CPlusPlus && SS.isEmpty() && Name && !Invalid) {
- // C++ [dcl.typedef]p3:
- // [...] Similarly, in a given scope, a class or enumeration
- // shall not be declared with the same name as a typedef-name
- // that is declared in that scope and refers to a type other
- // than the class or enumeration itself.
- LookupResult Lookup(*this, Name, NameLoc, LookupOrdinaryName,
- ForRedeclaration);
- LookupName(Lookup, S);
- TypedefDecl *PrevTypedef = Lookup.getAsSingle<TypedefDecl>();
- NamedDecl *PrevTypedefNamed = PrevTypedef;
- if (PrevTypedef && isDeclInScope(PrevTypedefNamed, SearchDC, S) &&
- Context.getCanonicalType(Context.getTypeDeclType(PrevTypedef)) !=
- Context.getCanonicalType(Context.getTypeDeclType(New))) {
- Diag(Loc, diag::err_tag_definition_of_typedef)
- << Context.getTypeDeclType(New)
- << PrevTypedef->getUnderlyingType();
- Diag(PrevTypedef->getLocation(), diag::note_previous_definition);
- Invalid = true;
- }
- }
-
// If this is a specialization of a member class (of a class template),
// check the specialization.
if (isExplicitSpecialization && CheckMemberSpecialization(New, Previous))
diff --git a/clang/lib/Sema/SemaLookup.cpp b/clang/lib/Sema/SemaLookup.cpp
index 8de0c40..a7a1084 100644
--- a/clang/lib/Sema/SemaLookup.cpp
+++ b/clang/lib/Sema/SemaLookup.cpp
@@ -202,26 +202,6 @@
!D->getDeclContext()->isRecord();
}
-static bool IsAcceptableNestedNameSpecifierName(NamedDecl *D, unsigned IDNS) {
- // This lookup ignores everything that isn't a type.
-
- // This is a fast check for the far most common case.
- if (D->isInIdentifierNamespace(Decl::IDNS_Tag))
- return true;
-
- if (isa<UsingShadowDecl>(D))
- D = cast<UsingShadowDecl>(D)->getTargetDecl();
-
- return isa<TypeDecl>(D);
-}
-
-static bool IsAcceptableNamespaceName(NamedDecl *D, unsigned IDNS) {
- // We don't need to look through using decls here because
- // using decls aren't allowed to name namespaces.
-
- return isa<NamespaceDecl>(D) || isa<NamespaceAliasDecl>(D);
-}
-
/// Gets the default result filter for the given lookup.
static inline
LookupResult::ResultFilter getResultFilter(Sema::LookupNameKind NameKind) {
@@ -232,16 +212,12 @@
case Sema::LookupRedeclarationWithLinkage: // FIXME: check linkage, scoping
case Sema::LookupUsingDeclName:
case Sema::LookupObjCProtocolName:
+ case Sema::LookupNestedNameSpecifierName:
+ case Sema::LookupNamespaceName:
return &IsAcceptableIDNS;
case Sema::LookupOperatorName:
return &IsAcceptableOperatorName;
-
- case Sema::LookupNestedNameSpecifierName:
- return &IsAcceptableNestedNameSpecifierName;
-
- case Sema::LookupNamespaceName:
- return &IsAcceptableNamespaceName;
}
llvm_unreachable("unkknown lookup kind");
@@ -260,15 +236,25 @@
case Sema::LookupRedeclarationWithLinkage:
IDNS = Decl::IDNS_Ordinary;
if (CPlusPlus) {
- IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member;
+ IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace;
if (Redeclaration) IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend;
}
break;
case Sema::LookupTagName:
- IDNS = Decl::IDNS_Tag;
- if (CPlusPlus && Redeclaration)
- IDNS |= Decl::IDNS_TagFriend;
+ if (CPlusPlus) {
+ IDNS = Decl::IDNS_Type;
+
+ // When looking for a redeclaration of a tag name, we add:
+ // 1) TagFriend to find undeclared friend decls
+ // 2) Namespace because they can't "overload" with tag decls.
+ // 3) Tag because it includes class templates, which can't
+ // "overload" with tag decls.
+ if (Redeclaration)
+ IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace;
+ } else {
+ IDNS = Decl::IDNS_Tag;
+ }
break;
case Sema::LookupMemberName:
@@ -278,8 +264,11 @@
break;
case Sema::LookupNestedNameSpecifierName:
+ IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace;
+ break;
+
case Sema::LookupNamespaceName:
- IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member;
+ IDNS = Decl::IDNS_Namespace;
break;
case Sema::LookupUsingDeclName:
@@ -2134,7 +2123,7 @@
IEnd = Pos->second.end();
I != IEnd; ++I) {
// A tag declaration does not hide a non-tag declaration.
- if ((*I)->getIdentifierNamespace() == Decl::IDNS_Tag &&
+ if ((*I)->hasTagIdentifierNamespace() &&
(IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
Decl::IDNS_ObjCProtocol)))
continue;