C++-ify parser_state

This mildly C++-ifies parser_state and stap_parse_info -- just enough
to remove some cleanups.

This version includes the changes implemented by Simon.

Regression tested by the buildbot.

gdb/ChangeLog
2017-12-30  Tom Tromey  <tom@tromey.com>
	    Simon Marchi  <simon.marchi@ericsson.com>

	* stap-probe.h (struct stap_parse_info): Add constructor,
	destructor.
	* stap-probe.c (stap_parse_argument): Update.
	* rust-exp.y (rust_lex_tests): Update.
	* parser-defs.h (struct parser_state): Add constructor,
	destructor, release method.
	<expout>: Change type to expression_up.
	(null_post_parser): Change type.
	(initialize_expout, reallocate_expout): Remove.
	* parse.c (parser_state::parser_state): Rename from
	initialize_expout.
	(parser_state::release): Rename from reallocate_expout.
	(write_exp_elt, parse_exp_in_context_1, increase_expout_size):
	Update.
	(null_post_parser): Change type of "exp".
	* dtrace-probe.c (dtrace_probe::build_arg_exprs): Update.
	* ada-lang.c (resolve, resolve_subexp)
	(replace_operator_with_call): Change type of "expp".
	* language.h (struct language_defn) <la_post_parser>: Change type
	of "expp".

1 files changed, 2 insertions, 9 deletions

diff --git a/gdb/dtrace-probe.c b/gdb/dtrace-probe.c
index 3314445..40553d3 100644
--- a/gdb/dtrace-probe.c
+++ b/gdb/dtrace-probe.c
@@ -625,21 +625,15 @@ dtrace_probe::build_arg_exprs (struct gdbarch *gdbarch)
      value of the argument when executed at the PC of the probe.  */
   for (dtrace_probe_arg &arg : m_args)
     {
-      struct cleanup *back_to;
-      struct parser_state pstate;
-
       /* Initialize the expression buffer in the parser state.  The
 	 language does not matter, since we are using our own
 	 parser.  */
-      initialize_expout (&pstate, 10, current_language, gdbarch);
-      back_to = make_cleanup (free_current_contents, &pstate.expout);
+      parser_state pstate (10, current_language, gdbarch);
 
       /* The argument value, which is ABI dependent and casted to
 	 `long int'.  */
       gdbarch_dtrace_parse_probe_argument (gdbarch, &pstate, argc);
 
-      discard_cleanups (back_to);
-
       /* Casting to the expected type, but only if the type was
 	 recognized at probe load time.  Otherwise the argument will
 	 be evaluated as the long integer passed to the probe.  */
@@ -650,8 +644,7 @@ dtrace_probe::build_arg_exprs (struct gdbarch *gdbarch)
 	  write_exp_elt_opcode (&pstate, UNOP_CAST);
 	}
 
-      reallocate_expout (&pstate);
-      arg.expr = expression_up (pstate.expout);
+      arg.expr = pstate.release ();
       prefixify_expression (arg.expr.get ());
       ++argc;
     }