PR c++/87996 - size of array is negative error when SIZE_MAX/2 < sizeof(array) <= SIZE_MAX

gcc/ChangeLog:

	PR c++/87996
	* builtins.c (max_object_size): Move from here...
	* builtins.h (max_object_size): ...and here...
	* tree.c (max_object_size): ...to here...
	* tree.h (max_object_size): ...and here.

gcc/c-family/ChangeLog:

	PR c++/87996
	* c-common.c (invalid_array_size_error): New function.
	(valid_array_size_p): Call it.  Handle size as well as type.
	* c-common.h (valid_constant_size_p): New function.
	(enum cst_size_error): New type.

gcc/cp/ChangeLog:

	PR c++/87996
	* decl.c (compute_array_index_type_loc): Preserve signed sizes
	for diagnostics.  Call valid_array_size_p instead of error.
	* init.c (build_new_1): Compute size for diagnostic.  Call
	invalid_array_size_error
	(build_new): Call valid_array_size_p instead of error.

gcc/testsuite/ChangeLog:

	PR c++/87996
	* c-c++-common/array-5.c: New test.
	* c-c++-common/pr68107.c: Adjust text of diagnostics.
	* g++.dg/init/new38.C: Same.
	* g++.dg/init/new43.C: Same.
	* g++.dg/init/new44.C: Same.
	* g++.dg/init/new46.C: Same.
	* g++.dg/other/large-size-array.C: Same.
	* g++.dg/other/new-size-type.C: Same.
	* g++.dg/template/array30.C: Same.
	* g++.dg/template/array32.C: New test.
	* g++.dg/template/dependent-name3.C: Adjust.
	* gcc.dg/large-size-array-3.c: Same.
	* gcc.dg/large-size-array-5.c: Same.
	* gcc.dg/large-size-array.c: Same.
	* g++.old-deja/g++.brendan/array1.C: Same.
	* g++.old-deja/g++.mike/p6149.C: Same.

From-SVN: r268774

1 files changed, 40 insertions, 6 deletions

diff --git a/gcc/tree.c b/gcc/tree.c
index b8be295..af7abd8 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -7500,10 +7500,12 @@ compare_tree_int (const_tree t, unsigned HOST_WIDE_INT u)
 
 /* Return true if SIZE represents a constant size that is in bounds of
    what the middle-end and the backend accepts (covering not more than
-   half of the address-space).  */
+   half of the address-space).
+   When PERR is non-null, set *PERR on failure to the description of
+   why SIZE is not valid.  */
 
 bool
-valid_constant_size_p (const_tree size)
+valid_constant_size_p (const_tree size, cst_size_error *perr /* = NULL */)
 {
   if (POLY_INT_CST_P (size))
     {
@@ -7514,10 +7516,33 @@ valid_constant_size_p (const_tree size)
 	  return false;
       return true;
     }
-  if (! tree_fits_uhwi_p (size)
-      || TREE_OVERFLOW (size)
-      || tree_int_cst_sign_bit (size) != 0)
-    return false;
+
+  cst_size_error error;
+  if (!perr)
+    perr = &error;
+
+  if (TREE_OVERFLOW (size))
+    {
+      *perr = cst_size_overflow;
+      return false;
+    }
+
+  tree type = TREE_TYPE (size);
+  if (TYPE_UNSIGNED (type))
+    {
+      if (!tree_fits_uhwi_p (size)
+	  || tree_int_cst_sign_bit (size))
+	{
+	  *perr = cst_size_too_big;
+	  return false;
+	}
+    }
+  else if (tree_int_cst_sign_bit (size))
+    {
+      *perr = cst_size_negative;
+      return false;
+    }
+
   return true;
 }
 
@@ -15003,6 +15028,15 @@ const builtin_structptr_type builtin_structptr_types[6] =
   { const_fexcept_t_ptr_type_node, const_ptr_type_node, "fexcept_t" }
 };
 
+/* Return the maximum object size.  */
+
+tree
+max_object_size (void)
+{
+  /* To do: Make this a configurable parameter.  */
+  return TYPE_MAX_VALUE (ptrdiff_type_node);
+}
+
 #if CHECKING_P
 
 namespace selftest {