add parser and sema support for the funny ObjC '@defs' thing.

Patch by David Chisnall!


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@52586 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 65 insertions, 13 deletions

diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 46246e64ba..95344c438e 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -707,7 +707,7 @@ ParseStructDeclaration(DeclSpec &DS,
 ///       struct-declaration-list:
 ///         struct-declaration
 ///         struct-declaration-list struct-declaration
-/// [OBC]   '@' 'defs' '(' class-name ')'                         [TODO]
+/// [OBC]   '@' 'defs' '(' class-name ')'
 ///
 void Parser::ParseStructUnionBody(SourceLocation RecordLoc,
                                   unsigned TagType, DeclTy *TagDecl) {
@@ -736,18 +736,39 @@ void Parser::ParseStructUnionBody(SourceLocation RecordLoc,
     // Parse all the comma separated declarators.
     DeclSpec DS;
     FieldDeclarators.clear();
-    ParseStructDeclaration(DS, FieldDeclarators);
-    
-    // Convert them all to fields.
-    for (unsigned i = 0, e = FieldDeclarators.size(); i != e; ++i) {
-      FieldDeclarator &FD = FieldDeclarators[i];
-      // Install the declarator into the current TagDecl.
-      DeclTy *Field = Actions.ActOnField(CurScope,
-                                         DS.getSourceRange().getBegin(),
-                                         FD.D, FD.BitfieldSize);
-      FieldDecls.push_back(Field);
-    }
-    
+    if (!Tok.is(tok::at)) {
+      ParseStructDeclaration(DS, FieldDeclarators);
+      
+      // Convert them all to fields.
+      for (unsigned i = 0, e = FieldDeclarators.size(); i != e; ++i) {
+        FieldDeclarator &FD = FieldDeclarators[i];
+        // Install the declarator into the current TagDecl.
+        DeclTy *Field = Actions.ActOnField(CurScope,
+                                           DS.getSourceRange().getBegin(),
+                                           FD.D, FD.BitfieldSize);
+        FieldDecls.push_back(Field);
+      }
+    } else { // Handle @defs
+      ConsumeToken();
+      if (!Tok.isObjCAtKeyword(tok::objc_defs)) {
+        Diag(Tok, diag::err_unexpected_at);
+        SkipUntil(tok::semi, true, true);
+        continue;
+      }
+      ConsumeToken();
+      ExpectAndConsume(tok::l_paren, diag::err_expected_lparen);
+      if (!Tok.is(tok::identifier)) {
+        Diag(Tok, diag::err_expected_ident);
+        SkipUntil(tok::semi, true, true);
+        continue;
+      }
+      llvm::SmallVector<DeclTy*, 16> Fields;
+      Actions.ActOnDefs(CurScope, Tok.getLocation(), Tok.getIdentifierInfo(),
+          Fields);
+      FieldDecls.insert(FieldDecls.end(), Fields.begin(), Fields.end());
+      ConsumeToken();
+      ExpectAndConsume(tok::r_paren, diag::err_expected_rparen);
+    } 
 
     if (Tok.is(tok::semi)) {
       ConsumeToken();
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index b3b5941dc3..1d68160813 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -240,6 +240,8 @@ private:
   virtual DeclTy *ActOnTag(Scope *S, unsigned TagType, TagKind TK,
                            SourceLocation KWLoc, IdentifierInfo *Name,
                            SourceLocation NameLoc, AttributeList *Attr);
+  virtual void ActOnDefs(Scope *S, SourceLocation DeclStart, IdentifierInfo
+      *ClassName, llvm::SmallVector<DeclTy*, 16> &Decls);
   virtual DeclTy *ActOnField(Scope *S, SourceLocation DeclStart,
                              Declarator &D, ExprTy *BitfieldWidth);
   
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 7af557b1a8..ee1aad54ed 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -1731,6 +1731,35 @@ Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK,
   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,
+                         llvm::SmallVector<Sema::DeclTy*, 16> &ivars) {
+  if (Class->getSuperClass())
+    CollectIvars(Class->getSuperClass(), ivars);
+  ivars.append(Class->ivar_begin(), Class->ivar_end());
+}
+
+/// Called whenever @defs(ClassName) is encountered in the source.  Inserts the
+/// instance variables of ClassName into Decls.
+void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, 
+                     IdentifierInfo *ClassName,
+                     llvm::SmallVector<DeclTy*, 16> &Decls) {
+  // Check that ClassName is a valid class
+  ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName);
+  if (!Class) {
+    Diag(DeclStart, diag::err_undef_interface, ClassName->getName());
+    return;
+  }
+  // Add the isa pointer
+  Decls.push_back(FieldDecl::Create(Context, SourceLocation(),
+                                    &Context.Idents.get("isa"),
+                                    Context.getObjCClassType()));
+  // Collect the instance variables
+  CollectIvars(Class, Decls);
+}
+
+
 static bool CalcFakeICEVal(const Expr* Expr,
                            llvm::APSInt& Result,
                            ASTContext& Context) {