builtins.c (compute_objsize): Add an argument and set it to offset into destination.

gcc/ChangeLog:

	* builtins.c (compute_objsize): Add an argument and set it to offset
	into destination.
	* builtins.h (compute_objsize): Add an argument.
	* tree-object-size.c (addr_object_size): Add an argument and set it
	to offset into destination.
	(compute_builtin_object_size): Same.
	* tree-object-size.h (compute_builtin_object_size): Add an argument.
	* tree-ssa-strlen.c (get_addr_stridx): Add an argument and set it
	to offset into destination.
	(maybe_warn_overflow): New function.
	(handle_store): Call maybe_warn_overflow to issue warnings.

gcc/testsuite/ChangeLog:

	* c-c++-common/Wstringop-overflow-2.c: Adjust text of expected messages.
	* g++.dg/warn/Wstringop-overflow-3.C: Same.
	* gcc.dg/Wstringop-overflow-17.c: Same.

From-SVN: r279248

1 files changed, 19 insertions, 8 deletions

diff --git a/gcc/tree-object-size.c b/gcc/tree-object-size.c
index 6e79bbd..d591c36 100644
--- a/gcc/tree-object-size.c
+++ b/gcc/tree-object-size.c
@@ -55,7 +55,7 @@ static const unsigned HOST_WIDE_INT unknown[4] = {
 static tree compute_object_offset (const_tree, const_tree);
 static bool addr_object_size (struct object_size_info *,
 			      const_tree, int, unsigned HOST_WIDE_INT *,
-			      tree * = NULL);
+			      tree * = NULL, tree * = NULL);
 static unsigned HOST_WIDE_INT alloc_object_size (const gcall *, int);
 static tree pass_through_call (const gcall *);
 static void collect_object_sizes_for (struct object_size_info *, tree);
@@ -174,13 +174,15 @@ compute_object_offset (const_tree expr, const_tree var)
 static bool
 addr_object_size (struct object_size_info *osi, const_tree ptr,
 		  int object_size_type, unsigned HOST_WIDE_INT *psize,
-		  tree *pdecl /* = NULL */)
+		  tree *pdecl /* = NULL */, tree *poff /* = NULL */)
 {
   tree pt_var, pt_var_size = NULL_TREE, var_size, bytes;
 
-  tree dummy;
+  tree dummy_decl, dummy_off = size_zero_node;
   if (!pdecl)
-    pdecl = &dummy;
+    pdecl = &dummy_decl;
+  if (!poff)
+    poff = &dummy_off;
 
   gcc_assert (TREE_CODE (ptr) == ADDR_EXPR);
 
@@ -201,7 +203,7 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
 	  || TREE_CODE (TREE_OPERAND (pt_var, 0)) != SSA_NAME)
 	{
 	  compute_builtin_object_size (TREE_OPERAND (pt_var, 0),
-				       object_size_type & ~1, &sz, pdecl);
+				       object_size_type & ~1, &sz, pdecl, poff);
 	}
       else
 	{
@@ -376,6 +378,7 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
 	    bytes = size_zero_node;
 	  else
 	    bytes = size_binop (MINUS_EXPR, var_size, bytes);
+	  *poff = bytes;
 	}
       if (var != pt_var
 	  && pt_var_size
@@ -390,6 +393,7 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
 		bytes2 = size_zero_node;
 	      else
 		bytes2 = size_binop (MINUS_EXPR, pt_var_size, bytes2);
+	      *poff = size_binop (PLUS_EXPR, *poff, bytes2);
 	      bytes = size_binop (MIN_EXPR, bytes, bytes2);
 	    }
 	}
@@ -496,10 +500,16 @@ pass_through_call (const gcall *call)
 bool
 compute_builtin_object_size (tree ptr, int object_size_type,
 			     unsigned HOST_WIDE_INT *psize,
-			     tree *pdecl /* = NULL */)
+			     tree *pdecl /* = NULL */, tree *poff /* = NULL */)
 {
   gcc_assert (object_size_type >= 0 && object_size_type <= 3);
 
+  tree dummy_decl, dummy_off = size_zero_node;
+  if (!pdecl)
+    pdecl = &dummy_decl;
+  if (!poff)
+    poff = &dummy_off;
+
   /* Set to unknown and overwrite just before returning if the size
      could be determined.  */
   *psize = unknown[object_size_type];
@@ -508,7 +518,7 @@ compute_builtin_object_size (tree ptr, int object_size_type,
     init_offset_limit ();
 
   if (TREE_CODE (ptr) == ADDR_EXPR)
-    return addr_object_size (NULL, ptr, object_size_type, psize, pdecl);
+    return addr_object_size (NULL, ptr, object_size_type, psize, pdecl, poff);
 
   if (TREE_CODE (ptr) != SSA_NAME
       || !POINTER_TYPE_P (TREE_TYPE (ptr)))
@@ -533,11 +543,12 @@ compute_builtin_object_size (tree ptr, int object_size_type,
 
 	      if (tree_fits_shwi_p (offset)
 		  && compute_builtin_object_size (ptr, object_size_type,
-						  psize, pdecl))
+						  psize, pdecl, poff))
 		{
 		  /* Return zero when the offset is out of bounds.  */
 		  unsigned HOST_WIDE_INT off = tree_to_shwi (offset);
 		  *psize = off < *psize ? *psize - off : 0;
+		  *poff = offset;
 		  return true;
 		}
 	    }