[PATCH] Fix ubsan on mingw hosts (PR sanitizer/83014)

[Jakub Jelinek]

Hi!

>From my reading of the PR and looking around, I believe the reason
ubsan ICEs on mingw hosts is that it is the only host that redefines
HOST_LONG_LONG_FORMAT to "I64" instead of the usual "ll", but "%I64"
is nothing pp_format can handle, and indeed this spot in ubsan.c is
the only place that calls pp_printf with HOST_WIDE_INT_PRINT_DEC
or similar format specifier.  Instead, other spots use
pp_unsigned_wide_integer or pp_scalar on top of which it is defined
that does:
      sprintf (pp_buffer (PP)->digit_buffer, FORMAT, SCALAR); \
      pp_string (PP, pp_buffer (PP)->digit_buffer);           \
and thus uses the host *printf which handles "I64" and appends that
as a string.

Bootstrapped/regtested on x86_64-linux and i686-linux, no way to test
on mingw.  Ok for trunk? 

2017-11-23  Jakub Jelinek  <ja...@redhat.com>

        PR sanitizer/83014
        * ubsan.c (ubsan_type_descriptor): Use pp_unsigned_wide_integer
        instead of pp_printf with HOST_WIDE_INT_PRINT_DEC.  Avoid calling
        tree_to_uhwi twice.

        * gcc.dg/ubsan/pr83014.c: New test.

--- gcc/ubsan.c.jj      2017-11-13 09:31:33.000000000 +0100
+++ gcc/ubsan.c 2017-11-23 11:35:20.452162632 +0100
@@ -436,10 +436,10 @@ ubsan_type_descriptor (tree type, enum u
              && TYPE_MAX_VALUE (dom) != NULL_TREE
              && TREE_CODE (TYPE_MAX_VALUE (dom)) == INTEGER_CST)
            {
+             unsigned HOST_WIDE_INT m;
              if (tree_fits_uhwi_p (TYPE_MAX_VALUE (dom))
-                 && tree_to_uhwi (TYPE_MAX_VALUE (dom)) + 1 != 0)
-               pp_printf (&pretty_name, HOST_WIDE_INT_PRINT_DEC,
-                           tree_to_uhwi (TYPE_MAX_VALUE (dom)) + 1);
+                 && (m = tree_to_uhwi (TYPE_MAX_VALUE (dom))) + 1 != 0)
+               pp_unsigned_wide_integer (&pretty_name, m + 1);
              else
                pp_wide_int (&pretty_name,
                             wi::add (wi::to_widest (TYPE_MAX_VALUE (dom)), 1),
--- gcc/testsuite/gcc.dg/ubsan/pr83014.c.jj     2017-11-23 11:52:59.613932074 
+0100
+++ gcc/testsuite/gcc.dg/ubsan/pr83014.c        2017-11-23 11:53:30.867542456 
+0100
@@ -0,0 +1,12 @@
+/* PR sanitizer/83014 */
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=undefined" } */
+
+int
+foo (void)
+{
+  int data[5];
+  data[0] = 0;
+  data[5] = 0;
+  return data[0];
+}

        Jakub