Unused variable fixes related to conditional compilation

This patch fixes various unused variable warnings that are related to
conditional compilation.  In these cases, either the variable is now
protected by the same #if as its uses, or the declaration is simply
lowered into the conditionally-compiled block.

gdb/ChangeLog
2018-07-22  Tom Tromey  <tom@tromey.com>

	* windows-nat.c (saved_context): Conditionally define.
	* remote.c (remote_target::remote_btrace_maybe_reopen):
	Conditionally declare "warned".
	* inflow.c (sigquit_ours): Conditionally define.
	(new_tty): Move "tty" declaration inside #if.
	* guile/guile.c (guile_datadir): Conditionally define.
	* charset.c (set_be_le_names): Move some declarations inside #if.
	* btrace.c (parse_xml_btrace): Move "errcode" declaration inside
	#if.
	(parse_xml_btrace_conf): Likewise.

gdb/ChangeLog

@@ -1,3 +1,16 @@
+2018-07-22  Tom Tromey  <tom@tromey.com>
+
+	* windows-nat.c (saved_context): Conditionally define.
+	* remote.c (remote_target::remote_btrace_maybe_reopen):
+	Conditionally declare "warned".
+	* inflow.c (sigquit_ours): Conditionally define.
+	(new_tty): Move "tty" declaration inside #if.
+	* guile/guile.c (guile_datadir): Conditionally define.
+	* charset.c (set_be_le_names): Move some declarations inside #if.
+	* btrace.c (parse_xml_btrace): Move "errcode" declaration inside
+	#if.
+	(parse_xml_btrace_conf): Likewise.
+
 2018-07-22  Tom Tromey  <tom@tromey.com>
 
 	* spu-tdep.c (spu_get_overlay_table): Remove unused variable.

gdb/btrace.c

@@ -2202,10 +2202,9 @@ static const struct gdb_xml_element btrace_elements[] = {
 void
 parse_xml_btrace (struct btrace_data *btrace, const char *buffer)
 {
-  int errcode;
-
 #if defined (HAVE_LIBEXPAT)
 
+  int errcode;
   btrace_data result;
   result.format = BTRACE_FORMAT_NONE;
 
@@ -2303,10 +2302,9 @@ static const struct gdb_xml_element btrace_conf_elements[] = {
 void
 parse_xml_btrace_conf (struct btrace_config *conf, const char *xml)
 {
-  int errcode;
-
 #if defined (HAVE_LIBEXPAT)
 
+  int errcode;
   errcode = gdb_xml_parse_quick (_("btrace-conf"), "btrace-conf.dtd",
 				 btrace_conf_elements, xml, conf);
   if (errcode != 0)

gdb/charset.c

@@ -295,9 +295,6 @@ static struct gdbarch *be_le_arch;
 static void
 set_be_le_names (struct gdbarch *gdbarch)
 {
-  int i, len;
-  const char *target_wide;
-
   if (be_le_arch == gdbarch)
     return;
   be_le_arch = gdbarch;
@@ -307,6 +304,9 @@ set_be_le_names (struct gdbarch *gdbarch)
   target_wide_charset_le_name = "UTF-32LE";
   target_wide_charset_be_name = "UTF-32BE";
 #else
+  int i, len;
+  const char *target_wide;
+
   target_wide_charset_le_name = NULL;
   target_wide_charset_be_name = NULL;
 

gdb/guile/guile.c

@@ -46,8 +46,10 @@ int gdbscm_guile_major_version;
 int gdbscm_guile_minor_version;
 int gdbscm_guile_micro_version;
 
+#ifdef HAVE_GUILE
 /* The guile subdirectory within gdb's data-directory.  */
 static const char *guile_datadir;
+#endif
 
 /* Declared constants and enum for guile exception printing.  */
 const char gdbscm_print_excp_none[] = "none";

gdb/inflow.c

@@ -138,7 +138,9 @@ private:
    to SIG_IGN.  */
 
 static sighandler_t sigint_ours;
+#ifdef SIGQUIT
 static sighandler_t sigquit_ours;
+#endif
 
 /* The name of the tty (from the `tty' command) that we're giving to
    the inferior when starting it up.  This is only (and should only
@@ -825,11 +827,11 @@ check_syscall (const char *msg, int result)
 void
 new_tty (void)
 {
-  int tty;
-
   if (inferior_thisrun_terminal == 0)
     return;
 #if !defined(__GO32__) && !defined(_WIN32)
+  int tty;
+
 #ifdef TIOCNOTTY
   /* Disconnect the child process from our controlling terminal.  On some
      systems (SVR4 for example), this may cause a SIGTTOU, so temporarily

gdb/remote.c

@@ -13717,7 +13717,9 @@ remote_target::remote_btrace_maybe_reopen ()
   struct remote_state *rs = get_remote_state ();
   struct thread_info *tp;
   int btrace_target_pushed = 0;
+#if !defined (HAVE_LIBIPT)
   int warned = 0;
+#endif
 
   scoped_restore_current_thread restore_thread;
 

gdb/windows-nat.c

@@ -146,8 +146,10 @@ static GetConsoleFontSize_ftype *GetConsoleFontSize;
 
 static int have_saved_context;	/* True if we've saved context from a
 				   cygwin signal.  */
+#ifdef __CYGWIN__
 static CONTEXT saved_context;	/* Containes the saved context from a
 				   cygwin signal.  */
+#endif
 
 /* If we're not using the old Cygwin header file set, define the
    following which never should have been in the generic Win32 API