Patch to fix crash on mingw and nil-typenames.

[Joost van der Sluis <joost@cnoc.nl>]

Hi all,

This patch resolves crashes of gdb on mingw, because fprintf on mingw
does not substitute nil-string parameters.

2011-10-12  Joost van der Sluis  <joost@cnoc.nl>

        * gdbtypes.h Added TYPE_SAFE_NAME macro to get the name of a 
        type or "<unnamed type"> when there is no name assigned. 
        * gnu-v3-abi.c (gnuv3_rtti_type): Use TYPE_SAFE_NAME macro to
        avoid a sigint when no name is assigned.

--- a/gdb/gdbtypes.h
+++ b/gdb/gdbtypes.h
@@ -1220,6 +1220,11 @@ extern void allocate_gnat_aux_type (struct type *);
        || TYPE_NFN_FIELDS (thistype) == 0) \
    && (TYPE_STUB (thistype) || !TYPE_STUB_SUPPORTED (thistype)))
 
+/* A helper macro that returns the name of a type or "unnamed type" if the type
+   has no name.  */
+#define TYPE_SAFE_NAME(type) \
+  (TYPE_NAME (type) ? TYPE_NAME (type) : _("<unnamed type>"))
+
 /* A helper macro that returns the name of an error type.  If the type
    has a name, it is used; otherwise, a default is used.  */
 #define TYPE_ERROR_NAME(type) \
--- a/gdb/gnu-v3-abi.c
+++ b/gdb/gnu-v3-abi.c
@@ -319,7 +319,7 @@ gnuv3_rtti_type (struct value *value,
       || strncmp (vtable_symbol_name, "vtable for ", 11))
     {
       warning (_("can't find linker symbol for virtual table for `%s' value"),
-	       TYPE_NAME (values_type));
+	       TYPE_SAFE_NAME (values_type));
       if (vtable_symbol_name)
 	warning (_("  found `%s' instead"), vtable_symbol_name);
       return NULL;