OSDN Git Service

gcc/objc/Changelog:
[pf3gnuchains/gcc-fork.git] / gcc / tree-object-size.c
index 22c4951..35b3c44 100644 (file)
@@ -1,5 +1,6 @@
 /* __builtin_object_size (ptr, object_size_type) computation
-   Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010
+   Free Software Foundation, Inc.
    Contributed by Jakub Jelinek <jakub@redhat.com>
 
 This file is part of GCC.
@@ -25,6 +26,8 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree.h"
 #include "toplev.h"
 #include "diagnostic.h"
+#include "tree-pretty-print.h"
+#include "gimple-pretty-print.h"
 #include "tree-flow.h"
 #include "tree-pass.h"
 #include "tree-ssa-propagate.h"
@@ -42,7 +45,8 @@ struct object_size_info
 static unsigned HOST_WIDE_INT unknown[4] = { -1, -1, 0, 0 };
 
 static tree compute_object_offset (const_tree, const_tree);
-static unsigned HOST_WIDE_INT addr_object_size (const_tree, int);
+static unsigned HOST_WIDE_INT addr_object_size (struct object_size_info *,
+                                               const_tree, int);
 static unsigned HOST_WIDE_INT alloc_object_size (const_gimple, int);
 static tree pass_through_call (const_gimple);
 static void collect_object_sizes_for (struct object_size_info *, tree);
@@ -151,9 +155,10 @@ compute_object_offset (const_tree expr, const_tree var)
    If unknown, return unknown[object_size_type].  */
 
 static unsigned HOST_WIDE_INT
-addr_object_size (const_tree ptr, int object_size_type)
+addr_object_size (struct object_size_info *osi, const_tree ptr,
+                 int object_size_type)
 {
-  tree pt_var;
+  tree pt_var, pt_var_size = NULL_TREE, var_size, bytes;
 
   gcc_assert (TREE_CODE (ptr) == ADDR_EXPR);
 
@@ -162,58 +167,190 @@ addr_object_size (const_tree ptr, int object_size_type)
     pt_var = get_base_address (pt_var);
 
   if (pt_var
-      && (SSA_VAR_P (pt_var) || TREE_CODE (pt_var) == STRING_CST)
-      && TYPE_SIZE_UNIT (TREE_TYPE (pt_var))
-      && host_integerp (TYPE_SIZE_UNIT (TREE_TYPE (pt_var)), 1)
-      && (unsigned HOST_WIDE_INT)
-        tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (pt_var)), 1) < offset_limit)
+      && TREE_CODE (pt_var) == INDIRECT_REF
+      && TREE_CODE (TREE_OPERAND (pt_var, 0)) == SSA_NAME
+      && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (pt_var, 0))))
     {
-      tree bytes;
+      unsigned HOST_WIDE_INT sz;
 
-      if (pt_var != TREE_OPERAND (ptr, 0))
+      if (!osi || (object_size_type & 1) != 0)
+       sz = compute_builtin_object_size (TREE_OPERAND (pt_var, 0),
+                                         object_size_type & ~1);
+      else
        {
-         tree var;
+         tree var = TREE_OPERAND (pt_var, 0);
+         if (osi->pass == 0)
+           collect_object_sizes_for (osi, var);
+         if (bitmap_bit_p (computed[object_size_type],
+                           SSA_NAME_VERSION (var)))
+           sz = object_sizes[object_size_type][SSA_NAME_VERSION (var)];
+         else
+           sz = unknown[object_size_type];
+       }
 
-         if (object_size_type & 1)
+      if (sz != unknown[object_size_type] && sz < offset_limit)
+       pt_var_size = size_int (sz);
+    }
+  else if (pt_var
+          && (SSA_VAR_P (pt_var) || TREE_CODE (pt_var) == STRING_CST)
+          && TYPE_SIZE_UNIT (TREE_TYPE (pt_var))
+          && host_integerp (TYPE_SIZE_UNIT (TREE_TYPE (pt_var)), 1)
+          && (unsigned HOST_WIDE_INT)
+             tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (pt_var)), 1)
+             < offset_limit)
+    pt_var_size = TYPE_SIZE_UNIT (TREE_TYPE (pt_var));
+  else
+    return unknown[object_size_type];
+
+  if (pt_var != TREE_OPERAND (ptr, 0))
+    {
+      tree var;
+
+      if (object_size_type & 1)
+       {
+         var = TREE_OPERAND (ptr, 0);
+
+         while (var != pt_var
+                && TREE_CODE (var) != BIT_FIELD_REF
+                && TREE_CODE (var) != COMPONENT_REF
+                && TREE_CODE (var) != ARRAY_REF
+                && TREE_CODE (var) != ARRAY_RANGE_REF
+                && TREE_CODE (var) != REALPART_EXPR
+                && TREE_CODE (var) != IMAGPART_EXPR)
+           var = TREE_OPERAND (var, 0);
+         if (var != pt_var && TREE_CODE (var) == ARRAY_REF)
+           var = TREE_OPERAND (var, 0);
+         if (! TYPE_SIZE_UNIT (TREE_TYPE (var))
+             || ! host_integerp (TYPE_SIZE_UNIT (TREE_TYPE (var)), 1)
+             || (pt_var_size
+                 && tree_int_cst_lt (pt_var_size,
+                                     TYPE_SIZE_UNIT (TREE_TYPE (var)))))
+           var = pt_var;
+         else if (var != pt_var && TREE_CODE (pt_var) == INDIRECT_REF)
            {
-             var = TREE_OPERAND (ptr, 0);
-
-             while (var != pt_var
-                     && TREE_CODE (var) != BIT_FIELD_REF
-                     && TREE_CODE (var) != COMPONENT_REF
-                     && TREE_CODE (var) != ARRAY_REF
-                     && TREE_CODE (var) != ARRAY_RANGE_REF
-                     && TREE_CODE (var) != REALPART_EXPR
-                     && TREE_CODE (var) != IMAGPART_EXPR)
-               var = TREE_OPERAND (var, 0);
-             if (var != pt_var && TREE_CODE (var) == ARRAY_REF)
-               var = TREE_OPERAND (var, 0);
-             if (! TYPE_SIZE_UNIT (TREE_TYPE (var))
-                 || ! host_integerp (TYPE_SIZE_UNIT (TREE_TYPE (var)), 1)
-                 || tree_int_cst_lt (TYPE_SIZE_UNIT (TREE_TYPE (pt_var)),
-                                     TYPE_SIZE_UNIT (TREE_TYPE (var))))
+             tree v = var;
+             /* For &X->fld, compute object size only if fld isn't the last
+                field, as struct { int i; char c[1]; } is often used instead
+                of flexible array member.  */
+             while (v && v != pt_var)
+               switch (TREE_CODE (v))
+                 {
+                 case ARRAY_REF:
+                   if (TYPE_SIZE_UNIT (TREE_TYPE (TREE_OPERAND (v, 0)))
+                       && TREE_CODE (TREE_OPERAND (v, 1)) == INTEGER_CST)
+                     {
+                       tree domain
+                         = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (v, 0)));
+                       if (domain
+                           && TYPE_MAX_VALUE (domain)
+                           && TREE_CODE (TYPE_MAX_VALUE (domain))
+                              == INTEGER_CST
+                           && tree_int_cst_lt (TREE_OPERAND (v, 1),
+                                               TYPE_MAX_VALUE (domain)))
+                         {
+                           v = NULL_TREE;
+                           break;
+                         }
+                     }
+                   v = TREE_OPERAND (v, 0);
+                   break;
+                 case REALPART_EXPR:
+                 case IMAGPART_EXPR:
+                   v = NULL_TREE;
+                   break;
+                 case COMPONENT_REF:
+                   if (TREE_CODE (TREE_TYPE (v)) != ARRAY_TYPE)
+                     {
+                       v = NULL_TREE;
+                       break;
+                     }
+                   while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
+                     if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
+                         != UNION_TYPE
+                         && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
+                         != QUAL_UNION_TYPE)
+                       break;
+                     else
+                       v = TREE_OPERAND (v, 0);
+                   if (TREE_CODE (v) == COMPONENT_REF
+                       && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
+                          == RECORD_TYPE)
+                     {
+                       tree fld_chain = TREE_CHAIN (TREE_OPERAND (v, 1));
+                       for (; fld_chain; fld_chain = TREE_CHAIN (fld_chain))
+                         if (TREE_CODE (fld_chain) == FIELD_DECL)
+                           break;
+
+                       if (fld_chain)
+                         {
+                           v = NULL_TREE;
+                           break;
+                         }
+                       v = TREE_OPERAND (v, 0);
+                     }
+                   while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
+                     if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
+                         != UNION_TYPE
+                         && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
+                         != QUAL_UNION_TYPE)
+                       break;
+                     else
+                       v = TREE_OPERAND (v, 0);
+                   if (v != pt_var)
+                     v = NULL_TREE;
+                   else
+                     v = pt_var;
+                   break;
+                 default:
+                   v = pt_var;
+                   break;
+                 }
+             if (v == pt_var)
                var = pt_var;
            }
-         else
-           var = pt_var;
+       }
+      else
+       var = pt_var;
 
-         bytes = compute_object_offset (TREE_OPERAND (ptr, 0), var);
-         if (bytes != error_mark_node)
+      if (var != pt_var)
+       var_size = TYPE_SIZE_UNIT (TREE_TYPE (var));
+      else if (!pt_var_size)
+       return unknown[object_size_type];
+      else
+       var_size = pt_var_size;
+      bytes = compute_object_offset (TREE_OPERAND (ptr, 0), var);
+      if (bytes != error_mark_node)
+       {
+         if (TREE_CODE (bytes) == INTEGER_CST
+             && tree_int_cst_lt (var_size, bytes))
+           bytes = size_zero_node;
+         else
+           bytes = size_binop (MINUS_EXPR, var_size, bytes);
+       }
+      if (var != pt_var
+         && pt_var_size
+         && TREE_CODE (pt_var) == INDIRECT_REF
+         && bytes != error_mark_node)
+       {
+         tree bytes2 = compute_object_offset (TREE_OPERAND (ptr, 0), pt_var);
+         if (bytes2 != error_mark_node)
            {
-             if (TREE_CODE (bytes) == INTEGER_CST
-                 && tree_int_cst_lt (TYPE_SIZE_UNIT (TREE_TYPE (var)), bytes))
-               bytes = size_zero_node;
+             if (TREE_CODE (bytes2) == INTEGER_CST
+                 && tree_int_cst_lt (pt_var_size, bytes2))
+               bytes2 = size_zero_node;
              else
-               bytes = size_binop (MINUS_EXPR,
-                                   TYPE_SIZE_UNIT (TREE_TYPE (var)), bytes);
+               bytes2 = size_binop (MINUS_EXPR, pt_var_size, bytes2);
+             bytes = size_binop (MIN_EXPR, bytes, bytes2);
            }
        }
-      else
-       bytes = TYPE_SIZE_UNIT (TREE_TYPE (pt_var));
-
-      if (host_integerp (bytes, 1))
-       return tree_low_cst (bytes, 1);
     }
+  else if (!pt_var_size)
+    return unknown[object_size_type];
+  else
+    bytes = pt_var_size;
+
+  if (host_integerp (bytes, 1))
+    return tree_low_cst (bytes, 1);
 
   return unknown[object_size_type];
 }
@@ -246,7 +383,7 @@ alloc_object_size (const_gimple call, int object_size_type)
       if (TREE_CHAIN (p))
         arg2 = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (p)))-1;
     }
+
   if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
     switch (DECL_FUNCTION_CODE (callee))
       {
@@ -262,10 +399,10 @@ alloc_object_size (const_gimple call, int object_size_type)
 
   if (arg1 < 0 || arg1 >= (int)gimple_call_num_args (call)
       || TREE_CODE (gimple_call_arg (call, arg1)) != INTEGER_CST
-      || (arg2 >= 0 
+      || (arg2 >= 0
          && (arg2 >= (int)gimple_call_num_args (call)
              || TREE_CODE (gimple_call_arg (call, arg2)) != INTEGER_CST)))
-    return unknown[object_size_type];    
+    return unknown[object_size_type];
 
   if (arg2 >= 0)
     bytes = size_binop (MULT_EXPR,
@@ -331,11 +468,11 @@ compute_builtin_object_size (tree ptr, int object_size_type)
     init_offset_limit ();
 
   if (TREE_CODE (ptr) == ADDR_EXPR)
-    return addr_object_size (ptr, object_size_type);
+    return addr_object_size (NULL, ptr, object_size_type);
 
   if (TREE_CODE (ptr) == SSA_NAME
-          && POINTER_TYPE_P (TREE_TYPE (ptr))
-          && object_sizes[object_size_type] != NULL)
+      && POINTER_TYPE_P (TREE_TYPE (ptr))
+      && object_sizes[object_size_type] != NULL)
     {
       if (!bitmap_bit_p (computed[object_size_type], SSA_NAME_VERSION (ptr)))
        {
@@ -476,7 +613,7 @@ expr_object_size (struct object_size_info *osi, tree ptr, tree value)
              || !POINTER_TYPE_P (TREE_TYPE (value)));
 
   if (TREE_CODE (value) == ADDR_EXPR)
-    bytes = addr_object_size (value, object_size_type);
+    bytes = addr_object_size (osi, value, object_size_type);
   else
     bytes = unknown[object_size_type];
 
@@ -632,7 +769,7 @@ plus_stmt_object_size (struct object_size_info *osi, tree var, gimple stmt)
          unsigned HOST_WIDE_INT off = tree_low_cst (op1, 1);
 
           /* op0 will be ADDR_EXPR here.  */
-         bytes = compute_builtin_object_size (op0, object_size_type);
+         bytes = addr_object_size (osi, op0, object_size_type);
          if (bytes == unknown[object_size_type])
            ;
          else if (off > offset_limit)
@@ -976,7 +1113,7 @@ check_for_plus_in_loops (struct object_size_info *osi, tree var)
     {
       tree basevar = gimple_assign_rhs1 (stmt);
       tree cst = gimple_assign_rhs2 (stmt);
-           
+
       gcc_assert (TREE_CODE (cst) == INTEGER_CST);
 
       if (integer_zerop (cst))
@@ -1068,7 +1205,8 @@ compute_object_sizes (void)
                        result = fold_convert (size_type_node,
                                               integer_minus_one_node);
                      else if (object_size_type < 4)
-                       result = size_zero_node;
+                       result = fold_convert (size_type_node,
+                                              integer_zero_node);
                    }
                }
 
@@ -1111,8 +1249,8 @@ struct gimple_opt_pass pass_object_sizes =
   NULL,                                        /* sub */
   NULL,                                        /* next */
   0,                                   /* static_pass_number */
-  0,                                   /* tv_id */
-  PROP_cfg | PROP_ssa | PROP_alias,    /* properties_required */
+  TV_NONE,                             /* tv_id */
+  PROP_cfg | PROP_ssa,                 /* properties_required */
   0,                                   /* properties_provided */
   0,                                   /* properties_destroyed */
   0,                                   /* todo_flags_start */