Add support for parsing the objc_gc attribute. Tests will come shortly.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@55269 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 56 insertions, 2 deletions

diff --git a/clang.xcodeproj/project.pbxproj b/clang.xcodeproj/project.pbxproj
index c92c04ad12..7acc745bd2 100644
--- a/clang.xcodeproj/project.pbxproj
+++ b/clang.xcodeproj/project.pbxproj
@@ -375,7 +375,7 @@
 		DE224FF70C7AA98800D370A5 /* CGExprComplex.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = CGExprComplex.cpp; path = lib/CodeGen/CGExprComplex.cpp; sourceTree = "<group>"; };
 		DE22526F0C7E82D000D370A5 /* CGExprScalar.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = CGExprScalar.cpp; path = lib/CodeGen/CGExprScalar.cpp; sourceTree = "<group>"; };
 		DE2255FB0C8004E600D370A5 /* ParseDeclCXX.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = ParseDeclCXX.cpp; path = lib/Parse/ParseDeclCXX.cpp; sourceTree = "<group>"; };
-		DE22BCF10E14197E0094DC60 /* SemaDeclAttr.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SemaDeclAttr.cpp; path = lib/Sema/SemaDeclAttr.cpp; sourceTree = "<group>"; };
+		DE22BCF10E14197E0094DC60 /* SemaDeclAttr.cpp */ = {isa = PBXFileReference; fileEncoding = 4; indentWidth = 2; lastKnownFileType = sourcecode.cpp.cpp; name = SemaDeclAttr.cpp; path = lib/Sema/SemaDeclAttr.cpp; sourceTree = "<group>"; tabWidth = 2; };
 		DE344AB70AE5DF6D00DBC861 /* HeaderSearch.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; path = HeaderSearch.h; sourceTree = "<group>"; };
 		DE344B530AE5E46C00DBC861 /* HeaderSearch.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; path = HeaderSearch.cpp; sourceTree = "<group>"; };
 		DE3450D60AEB543100DBC861 /* DirectoryLookup.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; path = DirectoryLookup.h; sourceTree = "<group>"; };
@@ -434,7 +434,7 @@
 		DE67E7100C020ED400F66BC5 /* SemaExpr.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = SemaExpr.cpp; path = lib/Sema/SemaExpr.cpp; sourceTree = "<group>"; };
 		DE67E7120C020ED900F66BC5 /* SemaDecl.cpp */ = {isa = PBXFileReference; fileEncoding = 30; indentWidth = 2; lastKnownFileType = sourcecode.cpp.cpp; name = SemaDecl.cpp; path = lib/Sema/SemaDecl.cpp; sourceTree = "<group>"; tabWidth = 8; usesTabs = 0; };
 		DE67E7140C020EDF00F66BC5 /* Sema.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; name = Sema.h; path = lib/Sema/Sema.h; sourceTree = "<group>"; };
-		DE67E7160C020EE400F66BC5 /* Sema.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = Sema.cpp; path = lib/Sema/Sema.cpp; sourceTree = "<group>"; };
+		DE67E7160C020EE400F66BC5 /* Sema.cpp */ = {isa = PBXFileReference; fileEncoding = 30; indentWidth = 2; lastKnownFileType = sourcecode.cpp.cpp; name = Sema.cpp; path = lib/Sema/Sema.cpp; sourceTree = "<group>"; tabWidth = 2; };
 		DE67E7190C020F4F00F66BC5 /* ParseAST.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = ParseAST.cpp; path = lib/Sema/ParseAST.cpp; sourceTree = "<group>"; };
 		DE67E7270C02109800F66BC5 /* ParseAST.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; name = ParseAST.h; path = clang/Sema/ParseAST.h; sourceTree = "<group>"; };
 		DE6951C60C4D1F5D00A5826B /* RecordLayout.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; name = RecordLayout.h; path = clang/AST/RecordLayout.h; sourceTree = "<group>"; };
diff --git a/include/clang/AST/Attr.h b/include/clang/AST/Attr.h
index 54f1714715..0d4c355ad1 100644
--- a/include/clang/AST/Attr.h
+++ b/include/clang/AST/Attr.h
@@ -40,6 +40,7 @@ public:
     NonNull,
     NoReturn,
     NoThrow,
+    ObjCGC,
     Packed,
     StdCall,
     TransparentUnion,
@@ -343,6 +344,25 @@ public:
   static bool classof(const TransparentUnionAttr *A) { return true; }
 };
 
+class ObjCGCAttr : public Attr {
+public:
+  enum GCAttrTypes {
+    Weak = 0,
+    Strong
+  };
+private:
+  GCAttrTypes GCAttrType;
+public:
+  ObjCGCAttr(GCAttrTypes t) : Attr(ObjCGC), GCAttrType(t) {}
+
+  GCAttrTypes getType() const { return GCAttrType; }
+
+  // Implement isa/cast/dyncast/etc.
+
+  static bool classof(const Attr *A) { return A->getKind() == ObjCGC; }
+  static bool classof(const ObjCGCAttr *A) { return true; }
+};
+
 }  // end namespace clang
 
 #endif
diff --git a/include/clang/Parse/AttributeList.h b/include/clang/Parse/AttributeList.h
index 0b27860699..b6efce388f 100644
--- a/include/clang/Parse/AttributeList.h
+++ b/include/clang/Parse/AttributeList.h
@@ -70,6 +70,7 @@ public:
     AT_visibility,
     AT_warn_unused_result,
     AT_weak,
+    AT_objc_gc,
     UnknownAttribute
   };
   
diff --git a/lib/Parse/AttributeList.cpp b/lib/Parse/AttributeList.cpp
index b120f7eda8..00da27cf0e 100644
--- a/lib/Parse/AttributeList.cpp
+++ b/lib/Parse/AttributeList.cpp
@@ -70,6 +70,7 @@ AttributeList::Kind AttributeList::getKind(const IdentifierInfo *Name) {
     if (!memcmp(Str, "aligned", 7)) return AT_aligned;
     if (!memcmp(Str, "nothrow", 7)) return AT_nothrow;
     if (!memcmp(Str, "nonnull", 7)) return AT_nonnull;
+    if (!memcmp(Str, "objc_gc", 7)) return AT_objc_gc;
     if (!memcmp(Str, "stdcall", 7)) return AT_stdcall;
     break;
   case 8:
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index fd1b3e7a49..2cfb3b9b96 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -466,6 +466,37 @@ static void HandleVisibilityAttr(Decl *d, const AttributeList &Attr, Sema &S) {
   d->addAttr(new VisibilityAttr(type));
 }
 
+static void HandleObjCGCAttr(Decl *d, const AttributeList &Attr, Sema &S) {
+  if (!Attr.getParameterName()) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_argument_n_not_string,
+           "objc_gc", std::string("1"));
+    return;
+  }
+  
+  if (Attr.getNumArgs() != 0) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments,
+           std::string("1"));
+    return;
+  }
+  
+  const char *TypeStr = Attr.getParameterName()->getName();
+  unsigned TypeLen = Attr.getParameterName()->getLength();
+  
+  ObjCGCAttr::GCAttrTypes type;
+  
+  if (TypeLen == 4 && !memcmp(TypeStr, "weak", 4))
+    type = ObjCGCAttr::Weak;
+  else if (TypeLen == 5 && !memcmp(TypeStr, "strong", 5))
+    type = ObjCGCAttr::Strong;
+  else {
+    S.Diag(Attr.getLoc(), diag::warn_attribute_type_not_supported,
+           "objc_gc", TypeStr);
+    return;
+  }
+  
+  d->addAttr(new ObjCGCAttr(type));
+}
+
 static void HandleWeakAttr(Decl *d, const AttributeList &Attr, Sema &S) {
   // check the attribute arguments.
   if (Attr.getNumArgs() != 0) {
@@ -909,6 +940,7 @@ static void ProcessDeclAttribute(Decl *D, const AttributeList &Attr, Sema &S) {
   case AttributeList::AT_transparent_union:
     HandleTransparentUnionAttr(D, Attr, S);
     break;
+  case AttributeList::AT_objc_gc:     HandleObjCGCAttr    (D, Attr, S); break;
   default:
 #if 0
     // TODO: when we have the full set of attributes, warn about unknown ones.