fix compile_rx_or_error

compile_rx_or_error looks like a constructor, but it can return NULL.
This patch changes it to remove the NULL return, making it work
like any other cleanup constructor.

This is a stylistic patch but I think it is also better for code to
follow the normal conventions.

	* probe.c (collect_probes): Check arguments for NULL before
	calling compile_rx_or_error.
	* utils.c (compile_rx_or_error): Require 'rx' to be non-NULL.
	Remove NULL return.

1 files changed, 3 insertions, 4 deletions

diff --git a/gdb/utils.c b/gdb/utils.c
index c25dadfe286..18ee9bbf98b 100644
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -1127,16 +1127,15 @@ get_regcomp_error (int code, regex_t *rx)
 }
 
 /* Compile a regexp and throw an exception on error.  This returns a
-   cleanup to free the resulting pattern on success.  If RX is NULL,
-   this does nothing and returns NULL.  */
+   cleanup to free the resulting pattern on success.  RX must not be
+   NULL.  */
 
 struct cleanup *
 compile_rx_or_error (regex_t *pattern, const char *rx, const char *message)
 {
   int code;
 
-  if (!rx)
-    return NULL;
+  gdb_assert (rx != NULL);
 
   code = regcomp (pattern, rx, REG_NOSUB);
   if (code != 0)