Detailed documentation for encoding of properties and a test 
case.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62607 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index bdcb7af..d1a8b82 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -1699,9 +1699,30 @@
 }
 
 /// getObjCEncodingForPropertyDecl - Return the encoded type for this
-/// method declaration. If non-NULL, Container must be either an
+/// property declaration. If non-NULL, Container must be either an
 /// ObjCCategoryImplDecl or ObjCImplementationDecl; it should only be
 /// NULL when getting encodings for protocol properties.
+/// Property attributes are stored as a comma-delimited C string. The simple 
+/// attributes readonly and bycopy are encoded as single characters. The 
+/// parametrized attributes, getter=name, setter=name, and ivar=name, are 
+/// encoded as single characters, followed by an identifier. Property types 
+/// are also encoded as a parametrized attribute. The characters used to encode 
+/// these attributes are defined by the following enumeration:
+/// @code
+/// enum PropertyAttributes {
+/// kPropertyReadOnly = 'R',   // property is read-only.
+/// kPropertyBycopy = 'C',     // property is a copy of the value last assigned
+/// kPropertyByref = '&',  // property is a reference to the value last assigned
+/// kPropertyDynamic = 'D',    // property is dynamic
+/// kPropertyGetter = 'G',     // followed by getter selector name
+/// kPropertySetter = 'S',     // followed by setter selector name
+/// kPropertyInstanceVariable = 'V'  // followed by instance variable  name
+/// kPropertyType = 't'              // followed by old-style type encoding.
+/// kPropertyWeak = 'W'              // 'weak' property
+/// kPropertyStrong = 'P'            // property GC'able
+/// kPropertyNonAtomic = 'N'         // property non-atomic
+/// };
+/// @endcode
 void ASTContext::getObjCEncodingForPropertyDecl(const ObjCPropertyDecl *PD, 
                                                 const Decl *Container,
                                                 std::string& S) {
diff --git a/test/CodeGenObjC/objc2-protocol-enc.m b/test/CodeGenObjC/objc2-protocol-enc.m
new file mode 100644
index 0000000..b0c1e7a
--- /dev/null
+++ b/test/CodeGenObjC/objc2-protocol-enc.m
@@ -0,0 +1,43 @@
+// RUN: clang -triple=i686-apple-darwin9 -fnext-runtime -emit-llvm -o %t %s &&
+// RUN: grep -e "T@\\\22<X>\\\22" %t &&
+// RUN: grep -e "T@\\\22<X><Y>\\\22" %t &&
+// RUN: grep -e "T@\\\22<X><Y><Z>\\\22" %t &&
+// RUN: grep -e "T@\\\22Foo<X><Y><Z>\\\22" %t
+
+@protocol X, Y, Z;
+@class Foo;
+
+@protocol Proto
+@property (copy) id <X> x;
+@property (copy) id <X, Y> xy;
+@property (copy) id <X, Y, Z> xyz;
+@property(copy)  Foo <X, Y, Z> *fooxyz;
+@end
+
+@interface Intf <Proto>
+{
+id <X> IVAR_x;
+id <X, Y> IVAR_xy;
+id <X, Y, Z> IVAR_xyz;
+Foo <X, Y, Z> *IVAR_Fooxyz;
+}
+@end
+
+@implementation Intf 
+@dynamic x, xy, xyz, fooxyz;
+@end
+
+/**
+This protocol should generate the following metadata:
+struct objc_property_list __Protocol_Test_metadata = {
+  sizeof(struct objc_property), 4,
+  {
+    { "x", "T@\"<X>\"" },
+    { "xy", "T@\"<X><Y>\"" },
+    { "xyz", "T@\"<X><Y><Z>\"" },
+    { "fooxyz", "T@\"Foo<X><Y><Z>\"" }
+  }
+};
+
+"T@\"<X><Y><Z>\",D
+*/