Make print_command_trace varargs

I noticed some code in execute_control_command_1 that could be
simplified by making print_command_trace a printf-like function.  This
patch makes this change.

ChangeLog
2018-05-04  Tom Tromey  <tom@tromey.com>

	* top.c (execute_command): Update.
	* cli/cli-script.h (print_command_lines): Now varargs.
	* cli/cli-script.c (print_command_lines): Now varargs.
	(execute_control_command_1) <case while_control, case if_control>:
	Update.

gdb/ChangeLog

@@ -1,3 +1,11 @@
+2018-05-04  Tom Tromey  <tom@tromey.com>
+
+	* top.c (execute_command): Update.
+	* cli/cli-script.h (print_command_lines): Now varargs.
+	* cli/cli-script.c (print_command_lines): Now varargs.
+	(execute_control_command_1) <case while_control, case if_control>:
+	Update.
+
 2018-05-04  Tom Tromey  <tom@tromey.com>
 
 	* tracepoint.c (all_tracepoint_actions): Rename from

gdb/cli/cli-script.c

@@ -426,8 +426,9 @@ reset_command_nest_depth (void)
    via while_command or if_command.  Inner levels of 'if' and 'while'
    are dealt with directly.  Therefore we can use these functions
    to determine whether the command has been printed already or not.  */
+ATTRIBUTE_PRINTF (1, 2)
 void
-print_command_trace (const char *cmd)
+print_command_trace (const char *fmt, ...)
 {
   int i;
 
@@ -443,7 +444,12 @@ print_command_trace (const char *cmd)
   for (i=0; i < command_nest_depth; i++)
     printf_filtered ("+");
 
-  printf_filtered ("%s\n", cmd);
+  va_list args;
+
+  va_start (args, fmt);
+  vprintf_filtered (fmt, args);
+  va_end (args);
+  puts_filtered ("\n");
 }
 
 /* Helper for execute_control_command.  */
@@ -490,11 +496,7 @@ execute_control_command_1 (struct command_line *cmd)
 
     case while_control:
       {
-	int len = strlen (cmd->line) + 7;
+	print_command_trace ("while %s", cmd->line);
-	char *buffer = (char *) alloca (len);
-
-	xsnprintf (buffer, len, "while %s", cmd->line);
-	print_command_trace (buffer);
 
 	/* Parse the loop control expression for the while statement.  */
 	std::string new_line = insert_user_defined_cmd_args (cmd->line);
@@ -555,11 +557,7 @@ execute_control_command_1 (struct command_line *cmd)
 
     case if_control:
       {
-	int len = strlen (cmd->line) + 4;
+	print_command_trace ("if %s", cmd->line);
-	char *buffer = (char *) alloca (len);
-
-	xsnprintf (buffer, len, "if %s", cmd->line);
-	print_command_trace (buffer);
 
 	/* Parse the conditional for the if statement.  */
 	std::string new_line = insert_user_defined_cmd_args (cmd->line);

gdb/cli/cli-script.h

@@ -148,7 +148,8 @@ extern std::string insert_user_defined_cmd_args (const char *line);
 
 /* Exported to top.c */
 
-extern void print_command_trace (const char *cmd);
+extern void print_command_trace (const char *cmd, ...)
+  ATTRIBUTE_PRINTF (1, 2);
 
 /* Exported to event-top.c */
 

gdb/top.c

@@ -571,7 +571,7 @@ execute_command (const char *p, int from_tty)
       line = p;
 
       /* If trace-commands is set then this will print this command.  */
-      print_command_trace (p);
+      print_command_trace ("%s", p);
 
       c = lookup_cmd (&cmd, cmdlist, "", 0, 1);
       p = cmd;