[C PATCH] Don't crash on null param (PR c/65066)

[Marek Polacek]

The CUR_PARAM can be null at this place, so check for that.

I had hoped that extra testing the original patch by running the C testsuite
with -Wformat=2 enabled would detect such a case, but apparently not. :(

Bootstrapped/regtested on x86_64-linux, ok for trunk?

2015-02-16  Marek Polacek  <pola...@redhat.com>

        PR c/65066
        * c-format.c (check_format_types): Handle null param.

        * gcc.dg/pr65066.c: New test.

diff --git gcc/c-family/c-format.c gcc/c-family/c-format.c
index 2f49b2d..9d03ff0 100644
--- gcc/c-family/c-format.c
+++ gcc/c-family/c-format.c
@@ -2492,6 +2492,7 @@ check_format_types (location_t loc, format_wanted_type 
*types)
          && TREE_CODE (cur_type) == INTEGER_TYPE
          && warn_format_signedness
          && TYPE_UNSIGNED (wanted_type)
+         && cur_param != NULL_TREE
          && TREE_CODE (cur_param) == NOP_EXPR)
        {
          tree t = TREE_TYPE (TREE_OPERAND (cur_param, 0));
diff --git gcc/testsuite/gcc.dg/pr65066.c gcc/testsuite/gcc.dg/pr65066.c
index e69de29..883a87d 100644
--- gcc/testsuite/gcc.dg/pr65066.c
+++ gcc/testsuite/gcc.dg/pr65066.c
@@ -0,0 +1,12 @@
+/* PR c/65066 */
+/* { dg-do compile } */
+/* { dg-options "-Wformat=2" } */
+
+extern int sscanf (const char *restrict, const char *restrict, ...);
+int *a;
+
+void
+foo ()
+{
+  sscanf (0, "0x%x  #", a); /* { dg-warning "expects argument of type" } */
+}

        Marek