C++-ify parse_format_string

This replaces parse_format_string with a class, removing some
constructors along the way.  While doing this, I found that one
argument to gen_printf is unused, so I removed it.

Also, I am not completely sure, but the use of `release' in
maint_agent_printf_command and parse_cmd_to_aexpr seems like it may
leak expressions.

Regression tested by the buildbot.

ChangeLog
2017-12-08  Tom Tromey  <tom@tromey.com>

	* printcmd.c (ui_printf): Update.  Use std::vector.
	* common/format.h (struct format_piece): Add constructor.
	<string>: Now const.
	(class format_pieces): New class.
	(parse_format_string, free_format_pieces)
	(free_format_pieces_cleanup): Remove.
	* common/format.c (format_pieces::format_pieces): Rename from
	parse_format_string.  Update.
	(free_format_pieces, free_format_pieces_cleanup): Remove.
	* breakpoint.c (parse_cmd_to_aexpr): Update.  Use std::vector.
	* ax-gdb.h (gen_printf): Remove argument.
	* ax-gdb.c (gen_printf): Remove "frags" argument.
	(maint_agent_printf_command): Update.  Use std::vector.

gdbserver/ChangeLog
2017-12-08  Tom Tromey  <tom@tromey.com>

	* ax.c (ax_printf): Update.

1 files changed, 4 insertions, 13 deletions

diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c
index 5027f6a..5a2a0a0 100644
--- a/gdb/ax-gdb.c
+++ b/gdb/ax-gdb.c
@@ -2541,7 +2541,6 @@ agent_expr_up
 gen_printf (CORE_ADDR scope, struct gdbarch *gdbarch,
 	    CORE_ADDR function, LONGEST channel,
 	    const char *format, int fmtlen,
-	    struct format_piece *frags,
 	    int nargs, struct expression **exprs)
 {
   agent_expr_up ax (new agent_expr (gdbarch, scope));
@@ -2681,12 +2680,8 @@ agent_eval_command (const char *exp, int from_tty)
 static void
 maint_agent_printf_command (const char *cmdrest, int from_tty)
 {
-  struct cleanup *old_chain = 0;
-  struct expression *argvec[100];
   struct frame_info *fi = get_current_frame ();	/* need current scope */
   const char *format_start, *format_end;
-  struct format_piece *fpieces;
-  int nargs;
 
   /* We don't deal with overlay debugging at the moment.  We need to
      think more carefully about this.  If you copy this code into
@@ -2705,9 +2700,7 @@ maint_agent_printf_command (const char *cmdrest, int from_tty)
 
   format_start = cmdrest;
 
-  fpieces = parse_format_string (&cmdrest);
-
-  old_chain = make_cleanup (free_format_pieces_cleanup, &fpieces);
+  format_pieces fpieces (&cmdrest);
 
   format_end = cmdrest;
 
@@ -2723,15 +2716,14 @@ maint_agent_printf_command (const char *cmdrest, int from_tty)
     cmdrest++;
   cmdrest = skip_spaces (cmdrest);
 
-  nargs = 0;
+  std::vector<struct expression *> argvec;
   while (*cmdrest != '\0')
     {
       const char *cmd1;
 
       cmd1 = cmdrest;
       expression_up expr = parse_exp_1 (&cmd1, 0, (struct block *) 0, 1);
-      argvec[nargs] = expr.release ();
-      ++nargs;
+      argvec.push_back (expr.release ());
       cmdrest = cmd1;
       if (*cmdrest == ',')
 	++cmdrest;
@@ -2742,14 +2734,13 @@ maint_agent_printf_command (const char *cmdrest, int from_tty)
   agent_expr_up agent = gen_printf (get_frame_pc (fi), get_current_arch (),
 				    0, 0,
 				    format_start, format_end - format_start,
-				    fpieces, nargs, argvec);
+				    argvec.size (), argvec.data ());
   ax_reqs (agent.get ());
   ax_print (gdb_stdout, agent.get ());
 
   /* It would be nice to call ax_reqs here to gather some general info
      about the expression, and then print out the result.  */
 
-  do_cleanups (old_chain);
   dont_repeat ();
 }