Adding some comments about AST node requirements for attributes which create AST...

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@197582 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/Attr.td b/include/clang/Basic/Attr.td
index 1dc44d812ccefd9d5e3f8b0b70461f5add34a482..38cf10bee3d69130590dc4dcfc3eea4ff515db4e 100644 (file)
--- a/include/clang/Basic/Attr.td
+++ b/include/clang/Basic/Attr.td
@@ -502,12 +502,17 @@ def GNUInline : InheritableAttr {
 def Hot : InheritableAttr {
   let Spellings = [GNU<"hot">, CXX11<"gnu", "hot">];
   let Subjects = SubjectList<[Function]>;
+  // An AST node is created for this attribute, but not actually used beyond
+  // semantic checking for mutual exclusion with the Cold attribute.
 }
 
 def IBAction : InheritableAttr {
   let Spellings = [GNU<"ibaction">];
   let Subjects = SubjectList<[ObjCInstanceMethod], WarnDiag,
                              "ExpectedObjCInstanceMethod">;
+  // An AST node is created for this attribute, but is not used by other parts
+  // of the compiler. However, this node needs to exist in the AST because
+  // external tools rely on it.
 }
 
 def IBOutlet : InheritableAttr {