From: Alex Denisov <1101.debian@gmail.com>
Date: Thu, 23 Jul 2015 21:53:13 +0000 (+0000)
Subject: Add documentation for the objc_boxable attribute
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=21442a13e0f425c450ceb6f67899157659f68c0b;p=clang

Add documentation for the objc_boxable attribute

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@243048 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Basic/Attr.td b/include/clang/Basic/Attr.td
index 753e42c950..d3b4555573 100644
--- a/include/clang/Basic/Attr.td
+++ b/include/clang/Basic/Attr.td
@@ -1143,7 +1143,7 @@ def ObjCRuntimeName : Attr {
 def ObjCBoxable : Attr {
   let Spellings = [GNU<"objc_boxable">];
   let Subjects = SubjectList<[Record], ErrorDiag, "ExpectedStructOrUnion">;
-  let Documentation = [Undocumented];
+  let Documentation = [ObjCBoxableDocs];
 }
 
 def OptimizeNone : InheritableAttr {
diff --git a/include/clang/Basic/AttrDocs.td b/include/clang/Basic/AttrDocs.td
index deaabc1939..0aeef2c4dd 100644
--- a/include/clang/Basic/AttrDocs.td
+++ b/include/clang/Basic/AttrDocs.td
@@ -492,6 +492,34 @@ can only be placed before an @protocol or @interface declaration:
     }];
 }
 
+def ObjCBoxableDocs : Documentation {
+    let Category = DocCatFunction;
+    let Content = [{
+Structs and unions marked with the ``objc_boxable`` attribute can be used 
+with the Objective-C boxed expression syntax, ``@(...)``.
+
+**Usage**: ``__attribute__((objc_boxable))``. This attribute 
+can only be placed on a declaration of a trivially-copyable struct or union:
+
+.. code-block:: objc
+
+  struct __attribute__((objc_boxable)) some_struct {
+    int i;
+  };
+  union __attribute__((objc_boxable)) some_union {
+    int i;
+    float f;
+  };
+  typedef struct __attribute__((objc_boxable)) _some_struct some_struct;
+
+  // ...
+
+  some_struct ss;
+  NSValue *boxed = @(ss);
+
+    }];
+}
+
 def AvailabilityDocs : Documentation {
   let Category = DocCatFunction;
   let Content = [{