tree.c (nonnull_arg_p): Move from ...

2015-08-13  Richard Biener  <rguenther@suse.de>

	* tree.c (nonnull_arg_p): Move from ...
	* tree-vrp.c (nonnull_arg_p): ... here.
	* tree.h (nonnull_arg_p): Declare.
	* tree-ssa-sccvn.c (init_scc_vn): Perform all lattice init
	here, register ptr != 0 for nonnull_arg_p pointer arguments.
	Properly initialize static chain and by-reference result pointer.
	(run_scc_vn): Adjust.

From-SVN: r226861

1 files changed, 63 insertions, 0 deletions

diff --git a/gcc/tree.c b/gcc/tree.c
index 3c2c20a..af3a6a3 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -13571,4 +13571,67 @@ verify_type (const_tree t)
     }
 }
 
+
+/* Return true if ARG is marked with the nonnull attribute in the
+   current function signature.  */
+
+bool
+nonnull_arg_p (const_tree arg)
+{
+  tree t, attrs, fntype;
+  unsigned HOST_WIDE_INT arg_num;
+
+  gcc_assert (TREE_CODE (arg) == PARM_DECL && POINTER_TYPE_P (TREE_TYPE (arg)));
+
+  /* The static chain decl is always non null.  */
+  if (arg == cfun->static_chain_decl)
+    return true;
+
+  /* THIS argument of method is always non-NULL.  */
+  if (TREE_CODE (TREE_TYPE (cfun->decl)) == METHOD_TYPE
+      && arg == DECL_ARGUMENTS (cfun->decl)
+      && flag_delete_null_pointer_checks)
+    return true;
+
+  /* Values passed by reference are always non-NULL.  */
+  if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE
+      && flag_delete_null_pointer_checks)
+    return true;
+
+  fntype = TREE_TYPE (cfun->decl);
+  for (attrs = TYPE_ATTRIBUTES (fntype); attrs; attrs = TREE_CHAIN (attrs))
+    {
+      attrs = lookup_attribute ("nonnull", attrs);
+
+      /* If "nonnull" wasn't specified, we know nothing about the argument.  */
+      if (attrs == NULL_TREE)
+	return false;
+
+      /* If "nonnull" applies to all the arguments, then ARG is non-null.  */
+      if (TREE_VALUE (attrs) == NULL_TREE)
+	return true;
+
+      /* Get the position number for ARG in the function signature.  */
+      for (arg_num = 1, t = DECL_ARGUMENTS (cfun->decl);
+	   t;
+	   t = DECL_CHAIN (t), arg_num++)
+	{
+	  if (t == arg)
+	    break;
+	}
+
+      gcc_assert (t == arg);
+
+      /* Now see if ARG_NUM is mentioned in the nonnull list.  */
+      for (t = TREE_VALUE (attrs); t; t = TREE_CHAIN (t))
+	{
+	  if (compare_tree_int (TREE_VALUE (t), arg_num) == 0)
+	    return true;
+	}
+    }
+
+  return false;
+}
+
+
 #include "gt-tree.h"