PR c/66970 - Add __has_builtin() macro

gcc/ChangeLog:

	PR c/66970
	* doc/cpp.texi (__has_builtin): Document.
	* doc/extend.texi (__builtin_frob_return_addr): Correct spelling.

gcc/c/ChangeLog:

	PR c/66970
	* c-decl.c (names_builtin_p): Define a new function.

gcc/c-family/ChangeLog:

	PR c/66970
	* c-common.c (c_common_nodes_and_builtins): Call c_define_builtins
	even when only preprocessing.
	* c-common.h (names_builtin_p): Declare new function.
	* c-lex.c (init_c_lex): Set has_builtin.
	(c_common_has_builtin): Define a new function.
	* c-ppoutput.c (init_pp_output): Set has_builtin.

gcc/cp/ChangeLog:

	PR c/66970
	* cp-objcp-common.c (names_builtin_p): Define new function.

gcc/testsuite/ChangeLog:

	PR c/66970
	* c-c++-common/cpp/has-builtin-2.c: New test.
	* c-c++-common/cpp/has-builtin-3.c: New test.
	* c-c++-common/cpp/has-builtin.c: New test.

From-SVN: r277544

4 files changed, 15 insertions, 5 deletions

diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index 224369b93ad..c655d3ffc90 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -676,6 +676,9 @@ struct cpp_callbacks
   /* Callback to identify whether an attribute exists.  */
   int (*has_attribute) (cpp_reader *);
 
+  /* Callback to determine whether a built-in function is recognized.  */
+  int (*has_builtin) (cpp_reader *);
+
   /* Callback that can change a user lazy into normal macro.  */
   void (*user_lazy_macro) (cpp_reader *, cpp_macro *, unsigned);
 
@@ -855,7 +858,8 @@ enum cpp_builtin_type
   BT_PRAGMA,			/* `_Pragma' operator */
   BT_TIMESTAMP,			/* `__TIMESTAMP__' */
   BT_COUNTER,			/* `__COUNTER__' */
-  BT_HAS_ATTRIBUTE		/* `__has_attribute__(x)' */
+  BT_HAS_ATTRIBUTE,		/* `__has_attribute__(x)' */
+  BT_HAS_BUILTIN		/* `__has_builtin(x)' */
 };
 
 #define CPP_HASHNODE(HNODE)	((cpp_hashnode *) (HNODE))
diff --git a/libcpp/init.c b/libcpp/init.c
index 4bcec7be3e5..b0943174f02 100644
--- a/libcpp/init.c
+++ b/libcpp/init.c
@@ -403,6 +403,7 @@ static const struct builtin_macro builtin_array[] =
   B("__COUNTER__",	 BT_COUNTER,       true),
   B("__has_attribute",	 BT_HAS_ATTRIBUTE, true),
   B("__has_cpp_attribute", BT_HAS_ATTRIBUTE, true),
+  B("__has_builtin",	 BT_HAS_BUILTIN,   true),
   /* Keep builtins not used for -traditional-cpp at the end, and
      update init_builtins() if any more are added.  */
   B("_Pragma",		 BT_PRAGMA,        true),
@@ -483,7 +484,8 @@ cpp_init_special_builtins (cpp_reader *pfile)
 
   for (b = builtin_array; b < builtin_array + n; b++)
     {
-      if (b->value == BT_HAS_ATTRIBUTE
+      if ((b->value == BT_HAS_ATTRIBUTE
+	   || b->value == BT_HAS_BUILTIN)
 	  && (CPP_OPTION (pfile, lang) == CLK_ASM
 	      || pfile->cb.has_attribute == NULL))
 	continue;
diff --git a/libcpp/macro.c b/libcpp/macro.c
index 30d3686451c..eb8321f8cee 100644
--- a/libcpp/macro.c
+++ b/libcpp/macro.c
@@ -568,6 +568,10 @@ _cpp_builtin_macro_text (cpp_reader *pfile, cpp_hashnode *node,
     case BT_HAS_ATTRIBUTE:
       number = pfile->cb.has_attribute (pfile);
       break;
+
+    case BT_HAS_BUILTIN:
+      number = pfile->cb.has_builtin (pfile);
+      break;
     }
 
   if (result == NULL)
diff --git a/libcpp/traditional.c b/libcpp/traditional.c
index f1e72796cf2..54738e8a169 100644
--- a/libcpp/traditional.c
+++ b/libcpp/traditional.c
@@ -326,9 +326,9 @@ static inline bool
 fun_like_macro (cpp_hashnode *node)
 {
   if (cpp_builtin_macro_p (node))
-    return node->value.builtin == BT_HAS_ATTRIBUTE;
-  else
-    return node->value.macro->fun_like;
+    return (node->value.builtin == BT_HAS_ATTRIBUTE
+	    || node->value.builtin == BT_HAS_BUILTIN);
+  return node->value.macro->fun_like;
 }
 
 /* Set up state for finding the opening '(' of a function-like