Create new EnumDecl nodes for redeclarations of enums, linking them
together in the same way that we link RecordDecl/CXXRecordDecl nodes.
Unify ActOnTag and ActOnTagStruct.
Fixes PR clang/2753.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@61034 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 253850a..17a6617 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2384,7 +2384,7 @@
SourceLocation KWLoc, const CXXScopeSpec &SS,
IdentifierInfo *Name, SourceLocation NameLoc,
AttributeList *Attr) {
- // If this is a use of an existing tag, it must have a name.
+ // If this is not a definition, it must have a name.
assert((Name != 0 || TK == TK_Definition) &&
"Nameless record must be a definition!");
@@ -2397,12 +2397,6 @@
case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break;
}
- // Two code paths: a new one for structs/unions/classes where we create
- // separate decls for forward declarations, and an old (eventually to
- // be removed) code path for enums.
- if (Kind != TagDecl::TK_enum)
- return ActOnTagStruct(S, Kind, TK, KWLoc, SS, Name, NameLoc, Attr);
-
DeclContext *DC = CurContext;
ScopedDecl *PrevDecl = 0;
@@ -2456,29 +2450,42 @@
Name = 0;
PrevDecl = 0;
} else {
- // If this is a use or a forward declaration, we're good.
- if (TK != TK_Definition)
- return PrevDecl;
+ // If this is a use, just return the declaration we found.
- // Diagnose attempts to redefine a tag.
- if (PrevTagDecl->isDefinition()) {
- Diag(NameLoc, diag::err_redefinition) << Name;
- Diag(PrevDecl->getLocation(), diag::note_previous_definition);
- // If this is a redefinition, recover by making this struct be
- // anonymous, which will make any later references get the previous
- // definition.
- Name = 0;
- } else {
- // Okay, this is definition of a previously declared or referenced
- // tag. Move the location of the decl to be the definition site.
- PrevDecl->setLocation(NameLoc);
+ // FIXME: In the future, return a variant or some other clue
+ // for the consumer of this Decl to know it doesn't own it.
+ // For our current ASTs this shouldn't be a problem, but will
+ // need to be changed with DeclGroups.
+ if (TK == TK_Reference)
return PrevDecl;
- }
+
+ // Diagnose attempts to redefine a tag.
+ if (TK == TK_Definition) {
+ if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) {
+ Diag(NameLoc, diag::err_redefinition) << Name;
+ Diag(Def->getLocation(), diag::note_previous_definition);
+ // If this is a redefinition, recover by making this struct be
+ // anonymous, which will make any later references get the previous
+ // definition.
+ Name = 0;
+ PrevDecl = 0;
+ }
+ // Okay, this is definition of a previously declared or referenced
+ // tag PrevDecl. We're going to create a new Decl for it.
+ }
}
+ // If we get here we have (another) forward declaration or we
+ // have a definition. Just create a new decl.
+ } else {
+ // If we get here, this is a definition of a new tag type in a nested
+ // scope, e.g. "struct foo; void bar() { struct foo; }", just create a
+ // new decl/type. We set PrevDecl to NULL so that the entities
+ // have distinct types.
+ PrevDecl = 0;
}
- // If we get here, this is a definition of a new struct type in a nested
- // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new
- // type.
+ // 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.
} else {
// PrevDecl is a namespace.
if (isDeclInScope(PrevDecl, DC, S)) {
@@ -2487,6 +2494,11 @@
Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
Diag(PrevDecl->getLocation(), diag::note_previous_definition);
Name = 0;
+ PrevDecl = 0;
+ } else {
+ // The existing declaration isn't relevant to us; we're in a
+ // new scope, so clear out the previous declaration.
+ PrevDecl = 0;
}
}
}
@@ -2498,12 +2510,15 @@
// keyword.
SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
- // Otherwise, if this is the first time we've seen this tag, create the decl.
+ // Otherwise, create a new declaration. If there is a previous
+ // declaration of the same entity, the two will be linked via
+ // PrevDecl.
TagDecl *New;
if (Kind == TagDecl::TK_enum) {
// FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
// enum X { A, B, C } D; D should chain to X.
- New = EnumDecl::Create(Context, DC, Loc, Name, 0);
+ New = EnumDecl::Create(Context, DC, Loc, Name,
+ cast_or_null<EnumDecl>(PrevDecl));
// If this is an undefined enum, warn.
if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum);
} else {
@@ -2513,10 +2528,35 @@
// struct X { int A; } D; D should chain to X.
if (getLangOptions().CPlusPlus)
// FIXME: Look for a way to use RecordDecl for simple structs.
- New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name);
+ New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name,
+ cast_or_null<CXXRecordDecl>(PrevDecl));
else
- New = RecordDecl::Create(Context, Kind, DC, Loc, Name);
+ New = RecordDecl::Create(Context, Kind, DC, Loc, Name,
+ cast_or_null<RecordDecl>(PrevDecl));
}
+
+ if (Kind != TagDecl::TK_enum) {
+ // Handle #pragma pack: if the #pragma pack stack has non-default
+ // alignment, make up a packed attribute for this decl. These
+ // attributes are checked when the ASTContext lays out the
+ // structure.
+ //
+ // It is important for implementing the correct semantics that this
+ // happen here (in act on tag decl). The #pragma pack stack is
+ // maintained as a result of parser callbacks which can occur at
+ // many points during the parsing of a struct declaration (because
+ // the #pragma tokens are effectively skipped over during the
+ // parsing of the struct).
+ if (unsigned Alignment = PackContext.getAlignment())
+ New->addAttr(new PackedAttr(Alignment * 8));
+ }
+
+ if (Attr)
+ ProcessDeclAttributeList(New, Attr);
+
+ // Set the lexical context. If the tag has a C++ scope specifier, the
+ // lexical context will be different from the semantic context.
+ New->setLexicalDeclContext(CurContext);
// If this has an identifier, add it to the scope stack.
if (Name) {
@@ -2528,182 +2568,10 @@
// Add it to the decl chain.
PushOnScopeChains(New, S);
}
-
- if (Attr)
- ProcessDeclAttributeList(New, Attr);
-
- // Set the lexical context. If the tag has a C++ scope specifier, the
- // lexical context will be different from the semantic context.
- New->setLexicalDeclContext(CurContext);
return New;
}
-/// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike
-/// the logic for enums, we create separate decls for forward declarations.
-/// This is called by ActOnTag, but eventually will replace its logic.
-Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK,
- SourceLocation KWLoc, const CXXScopeSpec &SS,
- IdentifierInfo *Name, SourceLocation NameLoc,
- AttributeList *Attr) {
- DeclContext *DC = CurContext;
- ScopedDecl *PrevDecl = 0;
-
- if (Name && SS.isNotEmpty()) {
- // We have a nested-name tag ('struct foo::bar').
-
- // Check for invalid 'foo::'.
- if (SS.isInvalid()) {
- Name = 0;
- goto CreateNewDecl;
- }
-
- DC = static_cast<DeclContext*>(SS.getScopeRep());
- // Look-up name inside 'foo::'.
- PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC));
-
- // A tag 'foo::bar' must already exist.
- if (PrevDecl == 0) {
- Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange();
- Name = 0;
- goto CreateNewDecl;
- }
- } else {
- // If this is a named struct, check to see if there was a previous forward
- // 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 (PrevDecl && PrevDecl->isTemplateParameter()) {
- // Maybe we will complain about the shadowed template parameter.
- DiagnoseTemplateParameterShadow(NameLoc, PrevDecl);
- // Just pretend that we didn't see the previous declaration.
- PrevDecl = 0;
- }
-
- if (PrevDecl) {
- assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) &&
- "unexpected Decl type");
-
- 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
- // rementions the tag), reuse the decl.
- if (TK == TK_Reference || isDeclInScope(PrevDecl, DC, S)) {
- // Make sure that this wasn't declared as an enum and now used as a
- // struct or something similar.
- if (PrevTagDecl->getTagKind() != Kind) {
- Diag(KWLoc, diag::err_use_with_wrong_tag) << Name;
- Diag(PrevDecl->getLocation(), diag::note_previous_use);
- // Recover by making this an anonymous redefinition.
- Name = 0;
- PrevDecl = 0;
- } else {
- // If this is a use, return the original decl.
-
- // FIXME: In the future, return a variant or some other clue
- // for the consumer of this Decl to know it doesn't own it.
- // For our current ASTs this shouldn't be a problem, but will
- // need to be changed with DeclGroups.
- if (TK == TK_Reference)
- return PrevDecl;
-
- // The new decl is a definition?
- if (TK == TK_Definition) {
- // Diagnose attempts to redefine a tag.
- if (RecordDecl* DefRecord =
- cast<RecordDecl>(PrevTagDecl)->getDefinition(Context)) {
- Diag(NameLoc, diag::err_redefinition) << Name;
- Diag(DefRecord->getLocation(), diag::note_previous_definition);
- // If this is a redefinition, recover by making this struct be
- // anonymous, which will make any later references get the previous
- // definition.
- Name = 0;
- PrevDecl = 0;
- }
- // Okay, this is definition of a previously declared or referenced
- // tag. We're going to create a new Decl.
- }
- }
- // If we get here we have (another) forward declaration. Just create
- // a new decl.
- }
- else {
- // If we get here, this is a definition of a new struct type in a nested
- // scope, e.g. "struct foo; void bar() { struct foo; }", just create a
- // new decl/type. We set PrevDecl to NULL so that the Records
- // have distinct types.
- PrevDecl = 0;
- }
- } else {
- // PrevDecl is a namespace.
- if (isDeclInScope(PrevDecl, DC, S)) {
- // The tag name clashes with a namespace name, 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;
- }
- }
- }
-
- CreateNewDecl:
-
- // If there is an identifier, use the location of the identifier as the
- // location of the decl, otherwise use the location of the struct/union
- // keyword.
- SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
-
- // Otherwise, if this is the first time we've seen this tag, create the decl.
- TagDecl *New;
-
- // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
- // struct X { int A; } D; D should chain to X.
- if (getLangOptions().CPlusPlus)
- // FIXME: Look for a way to use RecordDecl for simple structs.
- New = CXXRecordDecl::Create(Context, Kind, DC, Loc, Name,
- dyn_cast_or_null<CXXRecordDecl>(PrevDecl));
- else
- New = RecordDecl::Create(Context, Kind, DC, Loc, Name,
- dyn_cast_or_null<RecordDecl>(PrevDecl));
-
- // If this has an identifier, add it to the scope stack.
- if ((TK == TK_Definition || !PrevDecl) && Name) {
- // The scope passed in may not be a decl scope. Zip up the scope tree until
- // we find one that is.
- while ((S->getFlags() & Scope::DeclScope) == 0)
- S = S->getParent();
-
- // Add it to the decl chain.
- PushOnScopeChains(New, S);
- }
-
- // Handle #pragma pack: if the #pragma pack stack has non-default
- // alignment, make up a packed attribute for this decl. These
- // attributes are checked when the ASTContext lays out the
- // structure.
- //
- // It is important for implementing the correct semantics that this
- // happen here (in act on tag decl). The #pragma pack stack is
- // maintained as a result of parser callbacks which can occur at
- // many points during the parsing of a struct declaration (because
- // the #pragma tokens are effectively skipped over during the
- // parsing of the struct).
- if (unsigned Alignment = PackContext.getAlignment())
- New->addAttr(new PackedAttr(Alignment * 8));
-
- if (Attr)
- ProcessDeclAttributeList(New, Attr);
-
- // Set the lexical context. If the tag has a C++ scope specifier, the
- // lexical context will be different from the semantic context.
- New->setLexicalDeclContext(CurContext);
-
- return New;
-}
-
-
/// Collect the instance variables declared in an Objective-C object. Used in
/// the creation of structures from objects using the @defs directive.
static void CollectIvars(ObjCInterfaceDecl *Class, RecordDecl *Record,
@@ -3181,16 +3049,18 @@
DeclTy **Elements, unsigned NumElements) {
EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX));
- if (Enum && Enum->isDefinition()) {
- // Diagnose code like:
- // enum e0 {
- // E0 = sizeof(enum e0 { E1 })
- // };
- Diag(Enum->getLocation(), diag::err_nested_redefinition)
- << Enum->getDeclName();
- Diag(EnumLoc, diag::note_previous_definition);
- Enum->setInvalidDecl();
- return;
+ if (Enum) {
+ if (EnumDecl *Def = cast_or_null<EnumDecl>(Enum->getDefinition(Context))) {
+ // Diagnose code like:
+ // enum e0 {
+ // E0 = sizeof(enum e0 { E1 })
+ // };
+ Diag(Def->getLocation(), diag::err_nested_redefinition)
+ << Enum->getDeclName();
+ Diag(Enum->getLocation(), diag::note_previous_definition);
+ Enum->setInvalidDecl();
+ return;
+ }
}
// TODO: If the result value doesn't fit in an int, it must be a long or long
// long value. ISO C does not support this, but GCC does as an extension,