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

5 files changed, 67 insertions, 2 deletions

diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog
index 3b3d574..cfefb8e 100644
--- a/gcc/c-family/ChangeLog
+++ b/gcc/c-family/ChangeLog
@@ -1,3 +1,13 @@
+2019-10-28  Martin Sebor  <msebor@redhat.com>
+
+	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.
+
 2019-10-24  Jakub Jelinek  <jakub@redhat.com>
 
 	* c-common.h (c_omp_context_selector_matches): Remove.
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 483d874..79c047c 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -4468,8 +4468,7 @@ c_common_nodes_and_builtins (void)
       va_list_ref_type_node = build_reference_type (va_list_type_node);
     }
 
-  if (!flag_preprocess_only)
-    c_define_builtins (va_list_ref_type_node, va_list_arg_type_node);
+  c_define_builtins (va_list_ref_type_node, va_list_arg_type_node);
 
   main_identifier_node = get_identifier ("main");
 
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 7077183..42426ef 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -801,6 +801,7 @@ extern void c_register_addr_space (const char *str, addr_space_t as);
 extern bool in_late_binary_op;
 extern const char *c_addr_space_name (addr_space_t as);
 extern tree identifier_global_value (tree);
+extern bool names_builtin_p (const char *);
 extern tree c_linkage_bindings (tree);
 extern void record_builtin_type (enum rid, const char *, tree);
 extern tree build_void_list_node (void);
@@ -1022,6 +1023,7 @@ extern bool c_cpp_diagnostic (cpp_reader *, enum cpp_diagnostic_level,
 			      const char *, va_list *)
      ATTRIBUTE_GCC_DIAG(5,0);
 extern int c_common_has_attribute (cpp_reader *);
+extern int c_common_has_builtin (cpp_reader *);
 
 extern bool parse_optimize_options (tree, bool);
 
diff --git a/gcc/c-family/c-lex.c b/gcc/c-family/c-lex.c
index fb05b5f..42010a7 100644
--- a/gcc/c-family/c-lex.c
+++ b/gcc/c-family/c-lex.c
@@ -81,6 +81,7 @@ init_c_lex (void)
   cb->valid_pch = c_common_valid_pch;
   cb->read_pch = c_common_read_pch;
   cb->has_attribute = c_common_has_attribute;
+  cb->has_builtin = c_common_has_builtin;
   cb->get_source_date_epoch = cb_get_source_date_epoch;
   cb->get_suggestion = cb_get_suggestion;
   cb->remap_filename = remap_macro_filename;
@@ -386,6 +387,58 @@ c_common_has_attribute (cpp_reader *pfile)
 
   return result;
 }
+
+/* Callback for has_builtin.  */
+
+int
+c_common_has_builtin (cpp_reader *pfile)
+{
+  const cpp_token *token = get_token_no_padding (pfile);
+  if (token->type != CPP_OPEN_PAREN)
+    {
+      cpp_error (pfile, CPP_DL_ERROR,
+		 "missing '(' after \"__has_builtin\"");
+      return 0;
+    }
+
+  const char *name = "";
+  token = get_token_no_padding (pfile);
+  if (token->type == CPP_NAME)
+    {
+      name = (const char *) cpp_token_as_text (pfile, token);
+      token = get_token_no_padding (pfile);
+      if (token->type != CPP_CLOSE_PAREN)
+	{
+	  cpp_error (pfile, CPP_DL_ERROR,
+		     "expected ')' after \"%s\"", name);
+	  name = "";
+	}
+    }
+  else
+    {
+      cpp_error (pfile, CPP_DL_ERROR,
+		 "macro \"__has_builtin\" requires an identifier");
+      if (token->type == CPP_CLOSE_PAREN)
+	return 0;
+    }
+
+  /* Consume tokens up to the closing parenthesis, including any nested
+     pairs of parentheses, to avoid confusing redundant errors.  */
+  for (unsigned nparen = 1; ; token = get_token_no_padding (pfile))
+    {
+      if (token->type == CPP_OPEN_PAREN)
+	++nparen;
+      else if (token->type == CPP_CLOSE_PAREN)
+	--nparen;
+      else if (token->type == CPP_EOF)
+	break;
+      if (!nparen)
+	break;
+    }
+
+  return names_builtin_p (name);
+}
+
 
 /* Read a token and return its type.  Fill *VALUE with its value, if
    applicable.  Fill *CPP_FLAGS with the token's flags, if it is
diff --git a/gcc/c-family/c-ppoutput.c b/gcc/c-family/c-ppoutput.c
index 5f39198..91fabc7 100644
--- a/gcc/c-family/c-ppoutput.c
+++ b/gcc/c-family/c-ppoutput.c
@@ -151,6 +151,7 @@ init_pp_output (FILE *out_stream)
     }
 
   cb->has_attribute = c_common_has_attribute;
+  cb->has_builtin = c_common_has_builtin;
   cb->get_source_date_epoch = cb_get_source_date_epoch;
   cb->remap_filename = remap_macro_filename;