Cast the pointer assigned to ss_sp to char *.

FreeBSD versions older than 11.0 use char * as the type of ss_sp in
stack_t instead of the standards-defined void *.  C++ allows a char *
pointer to be converted to a void *, so it is safe to cast the return
value of xmalloc to char * if ss_sp is either a char * or void *.
Just always use the cast to char * since that is less ugly than having
to add a special case.

gdb/ChangeLog:

	* main.c (setup_alternate_signal_stack): Cast to char *.

2 files changed, 7 insertions, 1 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ca7c9de..05052c9 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2016-04-19  John Baldwin  <jhb@FreeBSD.org>
+
+	* main.c (setup_alternate_signal_stack): Cast to char *.
+
 2016-04-19  Doug Evans  <xdje42@gmail.com>
 
 	* symmisc.c (dump_symtab_1, dump_symtab): Delete arg objfile.
diff --git a/gdb/main.c b/gdb/main.c
index c149b70..2ce1713 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -297,7 +297,9 @@ setup_alternate_signal_stack (void)
 #ifdef HAVE_SIGALTSTACK
   stack_t ss;
 
-  ss.ss_sp = xmalloc (SIGSTKSZ);
+  /* FreeBSD versions older than 11.0 use char * for ss_sp instead of
+     void *.  This cast works with both types.  */
+  ss.ss_sp = (char *) xmalloc (SIGSTKSZ);
   ss.ss_size = SIGSTKSZ;
   ss.ss_flags = 0;