Change maybe_disable_address_space_randomization to a class

This changes maybe_disable_address_space_randomization to be an RAII
class, rather than having it return a cleanup.

Regression tested by the buildbot.

ChangeLog
2017-11-26  Tom Tromey  <tom@tromey.com>

	* nat/linux-personality.h (class
	maybe_disable_address_space_randomization): New class.
	(maybe_disable_address_space_randomization): Don't declare
	function.
	* nat/linux-personality.c (restore_personality)
	(make_disable_asr_cleanup): Remove.
	(maybe_disable_address_space_randomization): Now a constructor.
	(~maybe_disable_address_space_randomization): New destructor.
	* linux-nat.c (linux_nat_create_inferior): Update.

gdbserver/ChangeLog
2017-11-26  Tom Tromey  <tom@tromey.com>

	* linux-low.c (linux_create_inferior): Update.

2 files changed, 44 insertions, 54 deletions

diff --git a/gdb/nat/linux-personality.c b/gdb/nat/linux-personality.c
index 21a9ca9..bcec2ce 100644
--- a/gdb/nat/linux-personality.c
+++ b/gdb/nat/linux-personality.c
@@ -27,68 +27,43 @@
 # endif /* ! HAVE_DECL_ADDR_NO_RANDOMIZE */
 #endif /* HAVE_PERSONALITY */
 
-#ifdef HAVE_PERSONALITY
-
-/* Restore address space randomization of the inferior.  ARG is the
-   original inferior's personality value before the address space
-   randomization was disabled.  */
-
-static void
-restore_personality (void *arg)
-{
-  int personality_orig = (int) (uintptr_t) arg;
-
-  errno = 0;
-  personality (personality_orig);
-  if (errno != 0)
-    warning (_("Error restoring address space randomization: %s"),
-	     safe_strerror (errno));
-}
-#endif /* HAVE_PERSONALITY */
-
-/* Return a cleanup responsible for restoring the inferior's
-   personality (and restoring the inferior's address space
-   randomization) if HAVE_PERSONALITY and if PERSONALITY_SET is not
-   zero; return a null cleanup if not HAVE_PERSONALITY or if
-   PERSONALITY_SET is zero.  */
-
-static struct cleanup *
-make_disable_asr_cleanup (int personality_set, int personality_orig)
-{
-#ifdef HAVE_PERSONALITY
-  if (personality_set != 0)
-    return make_cleanup (restore_personality,
-			 (void *) (uintptr_t) personality_orig);
-#endif /* HAVE_PERSONALITY */
-
-  return make_cleanup (null_cleanup, NULL);
-}
-
 /* See comment on nat/linux-personality.h.  */
 
-struct cleanup *
+maybe_disable_address_space_randomization::
 maybe_disable_address_space_randomization (int disable_randomization)
+  : m_personality_set (false),
+    m_personality_orig (0)
 {
-  int personality_orig = 0;
-  int personality_set = 0;
-
 #ifdef HAVE_PERSONALITY
   if (disable_randomization)
     {
       errno = 0;
-      personality_orig = personality (0xffffffff);
-      if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
+      m_personality_orig = personality (0xffffffff);
+      if (errno == 0 && !(m_personality_orig & ADDR_NO_RANDOMIZE))
 	{
-	  personality_set = 1;
-	  personality (personality_orig | ADDR_NO_RANDOMIZE);
+	  m_personality_set = true;
+	  personality (m_personality_orig | ADDR_NO_RANDOMIZE);
 	}
-      if (errno != 0 || (personality_set
+      if (errno != 0 || (m_personality_set
 			 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
 	warning (_("Error disabling address space randomization: %s"),
 		 safe_strerror (errno));
     }
 #endif /* HAVE_PERSONALITY */
+}
+
+maybe_disable_address_space_randomization::
+~maybe_disable_address_space_randomization ()
+{
+#ifdef HAVE_PERSONALITY
 
-  return make_disable_asr_cleanup (personality_set,
-				   personality_orig);
+  if (m_personality_set)
+    {
+      errno = 0;
+      personality (m_personality_orig);
+      if (errno != 0)
+	warning (_("Error restoring address space randomization: %s"),
+		 safe_strerror (errno));
+    }
+#endif /* HAVE_PERSONALITY */
 }
diff --git a/gdb/nat/linux-personality.h b/gdb/nat/linux-personality.h
index 687086e..fcea02a 100644
--- a/gdb/nat/linux-personality.h
+++ b/gdb/nat/linux-personality.h
@@ -20,12 +20,27 @@
 #ifndef NAT_LINUX_PERSONALITY_H
 #define NAT_LINUX_PERSONALITY_H
 
-/* Disable the inferior's address space randomization if
-   DISABLE_RANDOMIZATION is not zero and if we have
-   <sys/personality.h>.  Return a cleanup which, when called, will
-   re-enable the inferior's address space randomization.  */
+class maybe_disable_address_space_randomization
+{
+public:
 
-extern struct cleanup *maybe_disable_address_space_randomization
-  (int disable_randomization);
+  /* Disable the inferior's address space randomization if
+     DISABLE_RANDOMIZATION is not zero and if we have
+     <sys/personality.h>. */
+  maybe_disable_address_space_randomization (int disable_randomization);
+
+  /* On destruction, re-enable address space randomization.  */
+  ~maybe_disable_address_space_randomization ();
+
+  DISABLE_COPY_AND_ASSIGN (maybe_disable_address_space_randomization);
+
+private:
+
+  /* True if the personality was set in the constructor.  */
+  bool m_personality_set;
+
+  /* If m_personality_set is true, the original personality value.  */
+  int m_personality_orig;
+};
 
 #endif /* ! NAT_LINUX_PERSONALITY_H */