[RFA 10/23] Remove make_cleanup_restore_current_language

Tom Tromey
2017-05-03T22:46:39Z

This patch replaces make_cleanup_restore_current_language with an RAII
class that saves the current language, and restores it when the object
is destroyed.

2017-05-02 Tom Tromey <tom@tromey.com>

* utils.h (make_cleanup_restore_current_language): Remove.
* utils.c (do_restore_current_language)
(make_cleanup_restore_current_language): Remove.
* parse.c (parse_exp_in_context_1)
(parse_expression_with_language): Use save_language.
* mi/mi-main.c (mi_cmd_execute): Use save_language.
* language.h (save_language): New class.
---
gdb/ChangeLog | 10 ++++++++++
gdb/language.h | 25 +++++++++++++++++++++++++
gdb/mi/mi-main.c | 6 ++----
gdb/parse.c | 22 +++++++---------------
gdb/utils.c | 22 ----------------------
gdb/utils.h | 2 --
6 files changed, 44 insertions(+), 43 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 50d8794..1c3b738 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,15 @@
2017-05-02 Tom Tromey <tom@tromey.com>

+ * utils.h (make_cleanup_restore_current_language): Remove.
+ * utils.c (do_restore_current_language)
+ (make_cleanup_restore_current_language): Remove.
+ * parse.c (parse_exp_in_context_1)
+ (parse_expression_with_language): Use save_language.
+ * mi/mi-main.c (mi_cmd_execute): Use save_language.
+ * language.h (save_language): New class.
+
+2017-05-02 Tom Tromey <tom@tromey.com>
+
* source.c (get_filename_and_charpos, forward_search_command)
(reverse_search_command): Use fd_closer.
* procfs.c (load_syscalls, proc_get_LDT_entry)
diff --git a/gdb/language.h b/gdb/language.h
index 58bcbe8..f543da5 100644
--- a/gdb/language.h
+++ b/gdb/language.h
@@ -609,4 +609,29 @@ void default_get_string (struct value *value, gdb_byte **buffer, int *length,
void c_get_string (struct value *value, gdb_byte **buffer, int *length,
struct type **char_type, const char **charset);

+/* Save the current language and restore it upon destruction. */
+
+class save_language
+{
+public:
+
+ explicit save_language (enum language new_lang)
+ : m_lang (current_language->la_language)
+ {
+ set_language (new_lang);
+ }
+
+ ~save_language ()
+ {
+ set_language (m_lang);
+ }
+
+ save_language (const save_language &) = delete;
+ save_language &operator= (const save_language &) = delete;
+
+private:
+
+ enum language m_lang;
+};
+
#endif /* defined (LANGUAGE_H) */
diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
index cb68fd6..aa44876 100644
--- a/gdb/mi/mi-main.c
+++ b/gdb/mi/mi-main.c
@@ -2242,11 +2242,9 @@ mi_cmd_execute (struct mi_parse *parse)
error (_("Invalid frame id: %d"), frame);
}

+ gdb::optional<save_language> lang_saver;
if (parse->language != language_unknown)
- {
- make_cleanup_restore_current_language ();
- set_language (parse->language);
- }
+ lang_saver.emplace (parse->language);

current_context = parse;

diff --git a/gdb/parse.c b/gdb/parse.c
index 3dd7075..84fce19 100644
--- a/gdb/parse.c
+++ b/gdb/parse.c
@@ -50,6 +50,7 @@
#include "objfiles.h"
#include "user-regs.h"
#include <algorithm>
+#include "common/gdb_optional.h"

/* Standard set of definitions for printing, dumping, prefixifying,
* and evaluating expressions. */
@@ -1136,7 +1137,7 @@ parse_exp_in_context_1 (const char **stringptr, CORE_ADDR pc,
const struct block *block,
int comma, int void_context_p, int *out_subexp)
{
- struct cleanup *old_chain, *inner_chain;
+ struct cleanup *old_chain;
const struct language_defn *lang = NULL;
struct parser_state ps;
int subexp;
@@ -1214,8 +1215,8 @@ parse_exp_in_context_1 (const char **stringptr, CORE_ADDR pc,
to the value matching SELECTED_FRAME as set by get_current_arch. */

initialize_expout (&ps, 10, lang, get_current_arch ());
- inner_chain = make_cleanup_restore_current_language ();
- set_language (lang->la_language);
+
+ save_language lang_saver (lang->la_language);

TRY
{
@@ -1250,7 +1251,6 @@ parse_exp_in_context_1 (const char **stringptr, CORE_ADDR pc,
if (expressiondebug)
dump_prefix_expression (ps.expout, gdb_stdlog);

- do_cleanups (inner_chain);
discard_cleanups (old_chain);

*stringptr = lexptr;
@@ -1275,19 +1275,11 @@ parse_expression (const char *string)
expression_up
parse_expression_with_language (const char *string, enum language lang)
{
- struct cleanup *old_chain = NULL;
-
+ gdb::optional<save_language> lang_saver;
if (current_language->la_language != lang)
- {
- old_chain = make_cleanup_restore_current_language ();
- set_language (lang);
- }
-
- expression_up expr = parse_expression (string);
+ lang_saver.emplace (lang);

- if (old_chain != NULL)
- do_cleanups (old_chain);
- return expr;
+ return parse_expression (string);
}

/* Parse STRING as an expression. If parsing ends in the middle of a
diff --git a/gdb/utils.c b/gdb/utils.c
index bffce78..1a66896 100644
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -307,28 +307,6 @@ make_cleanup_free_so (struct so_list *so)
return make_cleanup (do_free_so, so);
}

-/* Helper for make_cleanup_restore_current_language. */
-
-static void
-do_restore_current_language (void *p)
-{
- enum language saved_lang = (enum language) (uintptr_t) p;
-
- set_language (saved_lang);
-}
-
-/* Remember the current value of CURRENT_LANGUAGE and make it restored when
- the cleanup is run. */
-
-struct cleanup *
-make_cleanup_restore_current_language (void)
-{
- enum language saved_lang = current_language->la_language;
-
- return make_cleanup (do_restore_current_language,
- (void *) (uintptr_t) saved_lang);
-}
-
/* Helper function for make_cleanup_clear_parser_state. */

static void
diff --git a/gdb/utils.h b/gdb/utils.h
index 7afb3c5..1f01bdd 100644
--- a/gdb/utils.h
+++ b/gdb/utils.h
@@ -91,8 +91,6 @@ extern struct cleanup *make_cleanup_value_free (struct value *);
struct so_list;
extern struct cleanup *make_cleanup_free_so (struct so_list *so);

-extern struct cleanup *make_cleanup_restore_current_language (void);
-
/* A deleter for a hash table. */
struct htab_deleter
{
--
2.9.3