MFC r260014, r260099:

gcc: Add support for label attributes and "unavailable" attribute.

Apple GCC has extensions to support for both label attributes and
an "unavailable" attribute. These are critical for objc but are
also useful in regular C/C++.

Obtained from:	Apple GCC 4.2 - 5531

1 files changed, 53 insertions, 0 deletions

diff --git a/contrib/gcc/c-decl.c b/contrib/gcc/c-decl.c
index 3cdd69b..7b3833c 100644
--- a/contrib/gcc/c-decl.c
+++ b/contrib/gcc/c-decl.c
@@ -453,10 +453,17 @@ add_stmt (tree t)
    with __attribute__((deprecated)).  An object declared as
    __attribute__((deprecated)) suppresses warnings of uses of other
    deprecated items.  */
+/* APPLE LOCAL begin "unavailable" attribute (radar 2809697) */
+/* Also add an __attribute__((unavailable)).  An object declared as
+   __attribute__((unavailable)) suppresses any reports of being
+   declared with unavailable or deprecated items.  */
+/* APPLE LOCAL end "unavailable" attribute (radar 2809697) */
 
 enum deprecated_states {
   DEPRECATED_NORMAL,
   DEPRECATED_SUPPRESS
+  /* APPLE LOCAL "unavailable" attribute (radar 2809697) */
+  , DEPRECATED_UNAVAILABLE_SUPPRESS
 };
 
 static enum deprecated_states deprecated_state = DEPRECATED_NORMAL;
@@ -1709,6 +1716,12 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype)
   if (TREE_DEPRECATED (newdecl))
     TREE_DEPRECATED (olddecl) = 1;
 
+  /* APPLE LOCAL begin "unavailable" attribute (radar 2809697) */
+  /* Merge unavailableness.  */
+  if (TREE_UNAVAILABLE (newdecl))
+    TREE_UNAVAILABLE (olddecl) = 1;
+  /* APPLE LOCAL end "unavailable" attribute (radar 2809697) */
+
   /* Keep source location of definition rather than declaration and of
      prototype rather than non-prototype unless that prototype is
      built-in.  */
@@ -3222,8 +3235,36 @@ start_decl (struct c_declarator *declarator, struct c_declspecs *declspecs,
 
   /* An object declared as __attribute__((deprecated)) suppresses
      warnings of uses of other deprecated items.  */
+  /* APPLE LOCAL begin "unavailable" attribute (radar 2809697) */
+  /* An object declared as __attribute__((unavailable)) suppresses
+     any reports of being declared with unavailable or deprecated
+     items.  An object declared as __attribute__((deprecated))
+     suppresses warnings of uses of other deprecated items.  */
+#ifdef A_LESS_INEFFICENT_WAY /* which I really don't want to do!  */
   if (lookup_attribute ("deprecated", attributes))
     deprecated_state = DEPRECATED_SUPPRESS;
+  else if (lookup_attribute ("unavailable", attributes))
+    deprecated_state = DEPRECATED_UNAVAILABLE_SUPPRESS;
+#else /* a more efficient way doing what lookup_attribute would do */
+  tree a;
+
+  for (a = attributes; a; a = TREE_CHAIN (a))
+    {
+      tree name = TREE_PURPOSE (a);
+      if (TREE_CODE (name) == IDENTIFIER_NODE)
+        if (is_attribute_p ("deprecated", name))
+	  {
+	    deprecated_state = DEPRECATED_SUPPRESS;
+	    break;
+	  }
+        if (is_attribute_p ("unavailable", name))
+	  {
+	    deprecated_state = DEPRECATED_UNAVAILABLE_SUPPRESS;
+	    break;
+	  }
+    }
+#endif
+  /* APPLE LOCAL end "unavailable" attribute (radar 2809697) */
 
   decl = grokdeclarator (declarator, declspecs,
 			 NORMAL, initialized, NULL);
@@ -4087,6 +4128,11 @@ grokdeclarator (const struct c_declarator *declarator,
   /* If this looks like a function definition, make it one,
      even if it occurs where parms are expected.
      Then store_parm_decls will reject it and not use it as a parm.  */
+  /* APPLE LOCAL begin "unavailable" attribute (radar 2809697) */
+  if (declspecs->unavailable_p)
+    error_unavailable_use (declspecs->type);
+  else
+  /* APPLE LOCAL end "unavailable" attribute (radar 2809697) */
   if (decl_context == NORMAL && !funcdef_flag && current_scope->parm_flag)
     decl_context = PARM;
 
@@ -7267,6 +7313,8 @@ build_null_declspecs (void)
   ret->tag_defined_p = false;
   ret->explicit_signed_p = false;
   ret->deprecated_p = false;
+  /* APPLE LOCAL "unavailable" attribute (radar 2809697) */
+  ret->unavailable_p = false;
   ret->default_int_p = false;
   ret->long_p = false;
   ret->long_long_p = false;
@@ -7330,6 +7378,11 @@ declspecs_add_type (struct c_declspecs *specs, struct c_typespec spec)
   if (TREE_DEPRECATED (type))
     specs->deprecated_p = true;
 
+  /* APPLE LOCAL begin "unavailable" attribute (radar 2809697) */
+  if (TREE_UNAVAILABLE (type))
+    specs->unavailable_p = true;
+  /* APPLE LOCAL end "unavailable" attribute (radar 2809697) */
+
   /* Handle type specifier keywords.  */
   if (TREE_CODE (type) == IDENTIFIER_NODE && C_IS_RESERVED_WORD (type))
     {