zero-call-used-regs attr for ada

Make the zero_call_used_regs attribute usable as a Machine_Attribute
pragma.


for  gcc/ada/ChangeLog

	* gcc-interface/utils.c: Include opts.h.
	(handle_zero_call_used_regs_attribute): New.
	(gnat_internal_attribute_table): Add zero_call_used_regs.

for  gcc/testsuite/ChangeLog

	* gnat.dg/zcur_attr.adb, gnat.dg/zcur_attr.ads: New.

1 files changed, 59 insertions, 0 deletions

diff --git a/gcc/ada/gcc-interface/utils.c b/gcc/ada/gcc-interface/utils.c
index 4190855..be3f107 100644
--- a/gcc/ada/gcc-interface/utils.c
+++ b/gcc/ada/gcc-interface/utils.c
@@ -38,6 +38,7 @@
 #include "attribs.h"
 #include "varasm.h"
 #include "toplev.h"
+#include "opts.h"
 #include "output.h"
 #include "debug.h"
 #include "convert.h"
@@ -109,6 +110,8 @@ static tree handle_target_attribute (tree *, tree, tree, int, bool *);
 static tree handle_target_clones_attribute (tree *, tree, tree, int, bool *);
 static tree handle_vector_size_attribute (tree *, tree, tree, int, bool *);
 static tree handle_vector_type_attribute (tree *, tree, tree, int, bool *);
+static tree handle_zero_call_used_regs_attribute (tree *, tree, tree, int,
+						  bool *);
 
 static const struct attribute_spec::exclusions attr_cold_hot_exclusions[] =
 {
@@ -191,6 +194,9 @@ const struct attribute_spec gnat_internal_attribute_table[] =
   { "may_alias",    0, 0,  false, true,  false, false,
     NULL, NULL },
 
+  { "zero_call_used_regs", 1, 1, true, false, false, false,
+    handle_zero_call_used_regs_attribute, NULL },
+
   /* ??? format and format_arg are heavy and not supported, which actually
      prevents support for stdio builtins, which we however declare as part
      of the common builtins.def contents.  */
@@ -6987,6 +6993,59 @@ handle_vector_type_attribute (tree *node, tree name, tree ARG_UNUSED (args),
   return NULL_TREE;
 }
 
+/* Handle a "zero_call_used_regs" attribute; arguments as in
+   struct attribute_spec.handler.  */
+
+static tree
+handle_zero_call_used_regs_attribute (tree *node, tree name, tree args,
+				      int ARG_UNUSED (flags),
+				      bool *no_add_attrs)
+{
+  tree decl = *node;
+  tree id = TREE_VALUE (args);
+
+  if (TREE_CODE (decl) != FUNCTION_DECL)
+    {
+      error_at (DECL_SOURCE_LOCATION (decl),
+		"%qE attribute applies only to functions", name);
+      *no_add_attrs = true;
+      return NULL_TREE;
+    }
+
+  /* pragma Machine_Attribute turns string arguments into identifiers.
+     Reverse it.  */
+  if (TREE_CODE (id) == IDENTIFIER_NODE)
+    id = TREE_VALUE (args) = build_string
+      (IDENTIFIER_LENGTH (id), IDENTIFIER_POINTER (id));
+
+  if (TREE_CODE (id) != STRING_CST)
+    {
+      error_at (DECL_SOURCE_LOCATION (decl),
+		"%qE argument not a string", name);
+      *no_add_attrs = true;
+      return NULL_TREE;
+    }
+
+  bool found = false;
+  for (unsigned int i = 0; zero_call_used_regs_opts[i].name != NULL; ++i)
+    if (strcmp (TREE_STRING_POINTER (id),
+		zero_call_used_regs_opts[i].name) == 0)
+      {
+	found = true;
+	break;
+      }
+
+  if (!found)
+    {
+      error_at (DECL_SOURCE_LOCATION (decl),
+		"unrecognized %qE attribute argument %qs",
+		name, TREE_STRING_POINTER (id));
+      *no_add_attrs = true;
+    }
+
+  return NULL_TREE;
+}
+
 /* ----------------------------------------------------------------------- *
  *                              BUILTIN FUNCTIONS                          *
  * ----------------------------------------------------------------------- */