[PATCH v2 16/25] Simplify starting the command event loop

Pedro Alves
2016-03-21T15:29:38Z

All interpreter types (CLI/TUI/MI) print the prompt, and then call
start_event_loop.

Because we'll need an interpreter hook to display the
interpreter-specific prompt before going back to the event loop,
without actually starting an event loop, this patch moves the
start_event_loop call to common code, and replaces the command_loop
hook with a pre_command_look hook, that now just prints the prompt.

Turns out to be a cleanup on its own right anyway.
---
gdb/cli/cli-interp.c | 10 +++++++++-
gdb/cli/cli-interp.h | 2 ++
gdb/event-top.c | 13 -------------
gdb/interps.c | 16 ++++++----------
gdb/interps.h | 12 ++++++++----
gdb/main.c | 7 ++++++-
gdb/mi/mi-interp.c | 7 ++-----
gdb/tui/tui-interp.c | 2 +-
8 files changed, 34 insertions(+), 35 deletions(-)

diff --git a/gdb/cli/cli-interp.c b/gdb/cli/cli-interp.c
index 6e86e4d..11fad19 100644
--- a/gdb/cli/cli-interp.c
+++ b/gdb/cli/cli-interp.c
@@ -187,6 +187,14 @@ cli_on_command_error (void)
display_gdb_prompt (NULL);
}

+/* pre_command_loop implementation. */
+
+void
+cli_interpreter_pre_command_loop (struct interp *self)
+{
+ display_gdb_prompt (0);
+}
+
/* These implement the cli out interpreter: */

static void *
@@ -307,7 +315,7 @@ static const struct interp_procs cli_interp_procs = {
cli_interpreter_exec, /* exec_proc */
cli_ui_out, /* ui_out_proc */
NULL, /* set_logging_proc */
- cli_command_loop, /* command_loop_proc */
+ cli_interpreter_pre_command_loop, /* pre_command_loop_proc */
cli_interpreter_supports_command_editing, /* supports_command_editing_proc */
};

diff --git a/gdb/cli/cli-interp.h b/gdb/cli/cli-interp.h
index 07b7505..85be118 100644
--- a/gdb/cli/cli-interp.h
+++ b/gdb/cli/cli-interp.h
@@ -22,4 +22,6 @@ struct interp;

extern int cli_interpreter_supports_command_editing (struct interp *interp);

+extern void cli_interpreter_pre_command_loop (struct interp *self);
+
#endif
diff --git a/gdb/event-top.c b/gdb/event-top.c
index 63f15c5..db4cb5e 100644
--- a/gdb/event-top.c
+++ b/gdb/event-top.c
@@ -131,19 +131,6 @@ rl_callback_read_char_wrapper (gdb_client_data client_data)
(*after_char_processing_hook) ();
}

-/* Initialize all the necessary variables, start the event loop,
- register readline, and stdin, start the loop. The DATA is the
- interpreter data cookie, ignored for now. */
-
-void
-cli_command_loop (void *data)
-{
- display_gdb_prompt (0);
-
- /* Now it's time to start the event loop. */
- start_event_loop ();
-}
-
/* Change the function to be invoked every time there is a character
ready on stdin. This is used when the user sets the editing off,
therefore bypassing readline, and letting gdb handle the input
diff --git a/gdb/interps.c b/gdb/interps.c
index e9c96fd..90d0de8 100644
--- a/gdb/interps.c
+++ b/gdb/interps.c
@@ -107,9 +107,6 @@ interp_new (const char *name, const struct interp_procs *procs, void *data)
new_interp->procs = procs;
new_interp->inited = 0;

- /* Check for required procs. */
- gdb_assert (procs->command_loop_proc != NULL);
-
return new_interp;
}

@@ -383,16 +380,15 @@ command_interp (void)
return ui_interp->current_interpreter;
}

-/* Run the current command interpreter's main loop. */
+/* See interps.h. */
+
void
-current_interp_command_loop (void)
+interp_pre_command_loop (struct interp *interp)
{
- struct ui_interp_info *ui_interp = get_current_interp_info ();
- struct interp *interp = ui_interp->current_interpreter;
-
- gdb_assert (ui_interp->current_interpreter != NULL);
+ gdb_assert (interp != NULL);

- interp->procs->command_loop_proc (interp->data);
+ if (interp->procs->pre_command_loop_proc != NULL)
+ interp->procs->pre_command_loop_proc (interp);
}

/* See interp.h */
diff --git a/gdb/interps.h b/gdb/interps.h
index 7bcc0b9..6d8930f 100644
--- a/gdb/interps.h
+++ b/gdb/interps.h
@@ -43,7 +43,7 @@ typedef int (interp_resume_ftype) (void *data);
typedef int (interp_suspend_ftype) (void *data);
typedef struct gdb_exception (interp_exec_ftype) (void *data,
const char *command);
-typedef void (interp_command_loop_ftype) (void *data);
+typedef void (interp_pre_command_loop_ftype) (struct interp *self);
typedef struct ui_out *(interp_ui_out_ftype) (struct interp *self);

typedef int (interp_set_logging_ftype) (struct interp *self, int start_log,
@@ -70,7 +70,9 @@ struct interp_procs
disabled. */
interp_set_logging_ftype *set_logging_proc;

- interp_command_loop_ftype *command_loop_proc;
+ /* Called before starting an event loop, to give the interpreter a
+ chance to e.g., print a prompt. */
+ interp_pre_command_loop_ftype *pre_command_loop_proc;

/* Returns true if this interpreter supports using the readline
library; false if it uses GDB's own simplified readline
@@ -91,8 +93,6 @@ extern struct interp *interp_set_temp (const char *name);

extern int current_interp_named_p (const char *name);

-extern void current_interp_command_loop (void);
-
/* Call this function to give the current interpreter an opportunity
to do any special handling of streams when logging is enabled or
disabled. START_LOG is 1 when logging is starting, 0 when it ends,
@@ -115,6 +115,10 @@ extern void clear_interpreter_hooks (void);
if it uses GDB's own simplified form of readline. */
extern int interp_supports_command_editing (struct interp *interp);

+/* Called before starting an event loop, to give the interpreter a
+ chance to e.g., print a prompt. */
+extern void interp_pre_command_loop (struct interp *interp);
+
/* well-known interpreters */
#define INTERP_CONSOLE "console"
#define INTERP_MI1 "mi1"
diff --git a/gdb/main.c b/gdb/main.c
index d070b4d..1139487 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -313,7 +313,12 @@ captured_command_loop (void *data)
here on. */
current_ui->async = 1;

- current_interp_command_loop ();
+ /* Give the interpreter a chance to print a prompt. */
+ interp_pre_command_loop (top_level_interpreter ());
+
+ /* Now it's time to start the event loop. */
+ start_event_loop ();
+
/* FIXME: cagney/1999-11-05: A correct command_loop() implementaton
would clean things up (restoring the cleanup chain) to the state
they were just prior to the call. Technically, this means that
diff --git a/gdb/mi/mi-interp.c b/gdb/mi/mi-interp.c
index e1d186d..6d4936b 100644
--- a/gdb/mi/mi-interp.c
+++ b/gdb/mi/mi-interp.c
@@ -44,7 +44,6 @@

static void mi_execute_command_wrapper (const char *cmd);
static void mi_execute_command_input_handler (char *cmd);
-static void mi_command_loop (void *data);

/* These are hooks that we put in place while doing interpreter_exec
so we can report interesting things that happened "behind the MI's
@@ -323,7 +322,7 @@ mi_execute_command_input_handler (char *cmd)
}

static void
-mi_command_loop (void *data)
+mi_interpreter_pre_command_loop (struct interp *self)
{
/* Turn off 8 bit strings in quoted output. Any character with the
high bit set is printed using C's octal format. */
@@ -331,8 +330,6 @@ mi_command_loop (void *data)

/* Tell the world that we're alive. */
display_mi_prompt ();
-
- start_event_loop ();
}

static void
@@ -1330,7 +1327,7 @@ static const struct interp_procs mi_interp_procs =
mi_interpreter_exec, /* exec_proc */
mi_ui_out, /* ui_out_proc */
mi_set_logging, /* set_logging_proc */
- mi_command_loop /* command_loop_proc */
+ mi_interpreter_pre_command_loop /* pre_command_loop_proc */
};

static struct interp *
diff --git a/gdb/tui/tui-interp.c b/gdb/tui/tui-interp.c
index 2481a26..ef46837 100644
--- a/gdb/tui/tui-interp.c
+++ b/gdb/tui/tui-interp.c
@@ -273,7 +273,7 @@ static const struct interp_procs tui_interp_procs = {
tui_exec,
tui_ui_out,
NULL,
- cli_command_loop,
+ cli_interpreter_pre_command_loop,
cli_interpreter_supports_command_editing,
};

--
2.5.0