[PATCH v2 04/25] Introduce interpreter factories

Pedro Alves
2016-03-21T15:29:44Z

If every UI instance has its own set of interpreters, then the current
scheme of creating the interpreters at GDB initialization time no
longer works. We need to create them whenever a new UI instance is
created.

The scheme implemented here has each interpreter register an factory
callback that when called creates a new instance of a specific type.
Then, when some code in gdb looks up an interpreter (always by name),
if there's none yet, the factory method is called to construct one.

An alternative method I haven't tried would be to always create all
interpreters whenever a new UI instance is allocated.

I absolutely needed the lazy method in an earlier prototype of this
patch set, but it's not a requirement anymore. Doesn't hurt though.
---
gdb/cli/cli-interp.c | 83 +++++++++++++++++++++++++++++++-------------------
gdb/interps.c | 86 ++++++++++++++++++++++++++++++++++++++++++----------
gdb/interps.h | 11 ++++++-
gdb/mi/mi-interp.c | 36 +++++++++++++---------
gdb/tui/tui-interp.c | 34 +++++++++++++--------
5 files changed, 173 insertions(+), 77 deletions(-)

diff --git a/gdb/cli/cli-interp.c b/gdb/cli/cli-interp.c
index dfbd808..bd50af7 100644
--- a/gdb/cli/cli-interp.c
+++ b/gdb/cli/cli-interp.c
@@ -26,9 +26,14 @@
#include "infrun.h"
#include "observer.h"

-/* These are the ui_out and the interpreter for the console
- interpreter. */
-struct ui_out *cli_uiout;
+/* The console interpreter. */
+struct cli_interp
+{
+ /* The ui_out for the console interpreter. */
+ struct ui_out *cli_uiout;
+};
+
+/* The interpreter for the console interpreter. */
static struct interp *cli_interp;

/* Longjmp-safe wrapper for "execute_command". */
@@ -48,7 +53,7 @@ cli_on_normal_stop (struct bpstats *bs, int print_frame)
if (!interp_quiet_p (cli_interp))
{
if (print_frame)
- print_stop_event (cli_uiout);
+ print_stop_event (interp_ui_out (cli_interp));
}
}

@@ -58,7 +63,7 @@ static void
cli_on_signal_received (enum gdb_signal siggnal)
{
if (!interp_quiet_p (cli_interp))
- print_signal_received_reason (cli_uiout, siggnal);
+ print_signal_received_reason (interp_ui_out (cli_interp), siggnal);
}

/* Observer for the end_stepping_range notification. */
@@ -67,7 +72,7 @@ static void
cli_on_end_stepping_range (void)
{
if (!interp_quiet_p (cli_interp))
- print_end_stepping_range_reason (cli_uiout);
+ print_end_stepping_range_reason (interp_ui_out (cli_interp));
}

/* Observer for the signalled notification. */
@@ -76,7 +81,7 @@ static void
cli_on_signal_exited (enum gdb_signal siggnal)
{
if (!interp_quiet_p (cli_interp))
- print_signal_exited_reason (cli_uiout, siggnal);
+ print_signal_exited_reason (interp_ui_out (cli_interp), siggnal);
}

/* Observer for the exited notification. */
@@ -85,7 +90,7 @@ static void
cli_on_exited (int exitstatus)
{
if (!interp_quiet_p (cli_interp))
- print_exited_reason (cli_uiout, exitstatus);
+ print_exited_reason (interp_ui_out (cli_interp), exitstatus);
}

/* Observer for the no_history notification. */
@@ -94,7 +99,7 @@ static void
cli_on_no_history (void)
{
if (!interp_quiet_p (cli_interp))
- print_no_history_reason (cli_uiout);
+ print_no_history_reason (interp_ui_out (cli_interp));
}

/* Observer for the sync_execution_done notification. */
@@ -120,6 +125,9 @@ cli_on_command_error (void)
static void *
cli_interpreter_init (struct interp *self, int top_level)
{
+ if (top_level)
+ cli_interp = self;
+
/* If changing this, remember to update tui-interp.c as well. */
observer_attach_normal_stop (cli_on_normal_stop);
observer_attach_end_stepping_range (cli_on_end_stepping_range);
@@ -130,12 +138,13 @@ cli_interpreter_init (struct interp *self, int top_level)
observer_attach_sync_execution_done (cli_on_sync_execution_done);
observer_attach_command_error (cli_on_command_error);

- return NULL;
+ return interp_data (self);
}

static int
cli_interpreter_resume (void *data)
{
+ struct cli_interp *cli = (struct cli_interp *) data;
struct ui_file *stream;

/*sync_execution = 1; */
@@ -144,17 +153,17 @@ cli_interpreter_resume (void *data)
previously writing to gdb_stdout, then set it to the new
gdb_stdout afterwards. */

- stream = cli_out_set_stream (cli_uiout, gdb_stdout);
+ stream = cli_out_set_stream (cli->cli_uiout, gdb_stdout);
if (stream != gdb_stdout)
{
- cli_out_set_stream (cli_uiout, stream);
+ cli_out_set_stream (cli->cli_uiout, stream);
stream = NULL;
}

gdb_setup_readline ();

if (stream != NULL)
- cli_out_set_stream (cli_uiout, gdb_stdout);
+ cli_out_set_stream (cli->cli_uiout, gdb_stdout);

return 1;
}
@@ -169,6 +178,7 @@ cli_interpreter_suspend (void *data)
static struct gdb_exception
cli_interpreter_exec (void *data, const char *command_str)
{
+ struct cli_interp *cli = (struct cli_interp *) data;
struct ui_file *old_stream;
struct gdb_exception result;

@@ -184,9 +194,9 @@ cli_interpreter_exec (void *data, const char *command_str)

It is important that it gets reset everytime, since the user
could set gdb to use a different interpreter. */
- old_stream = cli_out_set_stream (cli_uiout, gdb_stdout);
- result = safe_execute_command (cli_uiout, str, 1);
- cli_out_set_stream (cli_uiout, old_stream);
+ old_stream = cli_out_set_stream (cli->cli_uiout, gdb_stdout);
+ result = safe_execute_command (cli->cli_uiout, str, 1);
+ cli_out_set_stream (cli->cli_uiout, old_stream);
return result;
}

@@ -222,7 +232,30 @@ safe_execute_command (struct ui_out *command_uiout, char *command, int from_tty)
static struct ui_out *
cli_ui_out (struct interp *self)
{
- return cli_uiout;
+ struct cli_interp *cli = (struct cli_interp *) interp_data (self);
+
+ return cli->cli_uiout;
+}
+
+static const struct interp_procs cli_interp_procs = {
+ cli_interpreter_init, /* init_proc */
+ cli_interpreter_resume, /* resume_proc */
+ cli_interpreter_suspend, /* suspend_proc */
+ cli_interpreter_exec, /* exec_proc */
+ cli_ui_out, /* ui_out_proc */
+ NULL, /* set_logging_proc */
+ cli_command_loop /* command_loop_proc */
+};
+
+static struct interp *
+cli_interp_factory (const char *name, struct ui *ui)
+{
+ struct cli_interp *cli = XNEW (struct cli_interp);
+
+ /* Create a default uiout builder for the CLI. */
+ cli->cli_uiout = cli_out_new (gdb_stdout);
+
+ return interp_new (name, &cli_interp_procs, cli);
}

/* Standard gdb initialization hook. */
@@ -231,19 +264,5 @@ extern initialize_file_ftype _initialize_cli_interp; /* -Wmissing-prototypes */
void
_initialize_cli_interp (void)
{
- static const struct interp_procs procs = {
- cli_interpreter_init, /* init_proc */
- cli_interpreter_resume, /* resume_proc */
- cli_interpreter_suspend, /* suspend_proc */
- cli_interpreter_exec, /* exec_proc */
- cli_ui_out, /* ui_out_proc */
- NULL, /* set_logging_proc */
- cli_command_loop /* command_loop_proc */
- };
-
- /* Create a default uiout builder for the CLI. */
- cli_uiout = cli_out_new (gdb_stdout);
- cli_interp = interp_new (INTERP_CONSOLE, &procs);
-
- interp_add (cli_interp);
+ interp_factory_register (INTERP_CONSOLE, cli_interp_factory);
}
diff --git a/gdb/interps.c b/gdb/interps.c
index 945b830..6626b4f 100644
--- a/gdb/interps.c
+++ b/gdb/interps.c
@@ -89,18 +89,20 @@ struct interp

void _initialize_interpreter (void);

+static struct interp *interp_lookup_existing (const char *name);
+
/* interp_new - This allocates space for a new interpreter,
fills the fields from the inputs, and returns a pointer to the
interpreter. */
struct interp *
-interp_new (const char *name, const struct interp_procs *procs)
+interp_new (const char *name, const struct interp_procs *procs, void *data)
{
struct interp *new_interp;

new_interp = XNEW (struct interp);

new_interp->name = xstrdup (name);
- new_interp->data = NULL;
+ new_interp->data = data;
new_interp->quiet_p = 0;
new_interp->procs = procs;
new_interp->inited = 0;
@@ -111,6 +113,32 @@ interp_new (const char *name, const struct interp_procs *procs)
return new_interp;
}

+struct interp_factory
+{
+ /* This is the name in "-i=" and set interpreter. */
+ const char *name;
+
+ /* The function that creates the interpreter. */
+ interp_factory_func func;
+};
+
+typedef struct interp_factory *interp_factory_p;
+DEF_VEC_P(interp_factory_p);
+
+static VEC(interp_factory_p) *interpreter_factories = NULL;
+
+void
+interp_factory_register (const char *name, interp_factory_func func)
+{
+ struct interp_factory *f = XNEW (struct interp_factory);
+
+ f->name = name;
+ f->func = func;
+
+ /* FIXME: assert that no factory for NAME is already registered. */
+ VEC_safe_push (interp_factory_p, interpreter_factories, f);
+}
+
/* Add interpreter INTERP to the gdb interpreter list. The
interpreter must not have previously been added. */
void
@@ -118,7 +146,7 @@ interp_add (struct interp *interp)
{
struct ui_interp_info *ui_interp = get_current_interp_info ();

- gdb_assert (interp_lookup (interp->name) == NULL);
+ gdb_assert (interp_lookup_existing (interp->name) == NULL);

interp->next = ui_interp->interp_list;
ui_interp->interp_list = interp;
@@ -217,18 +245,15 @@ interp_set (struct interp *interp, int top_level)
return 1;
}

-/* interp_lookup - Looks up the interpreter for NAME. If no such
- interpreter exists, return NULL, otherwise return a pointer to the
- interpreter. */
-struct interp *
-interp_lookup (const char *name)
+/* Look up the interpreter for NAME. If no such interpreter exists,
+ return NULL, otherwise return a pointer to the interpreter. */
+
+static struct interp *
+interp_lookup_existing (const char *name)
{
struct ui_interp_info *ui_interp = get_current_interp_info ();
struct interp *interp;

- if (name == NULL || strlen (name) == 0)
- return NULL;
-
for (interp = ui_interp->interp_list;
interp != NULL;
interp = interp->next)
@@ -240,6 +265,35 @@ interp_lookup (const char *name)
return NULL;
}

+struct interp *
+interp_lookup (const char *name)
+{
+ struct ui *ui = current_ui;
+ struct interp_factory *factory;
+ struct interp *interp;
+ int ix;
+
+ if (name == NULL || strlen (name) == 0)
+ return NULL;
+
+ /* Only create each interpreter once per top level. */
+ interp = interp_lookup_existing (name);
+ if (interp != NULL)
+ return interp;
+
+ for (ix = 0;
+ VEC_iterate (interp_factory_p, interpreter_factories, ix, factory);
+ ++ix)
+ if (strcmp (factory->name, name) == 0)
+ {
+ interp = factory->func (name, ui);
+ interp_add (interp);
+ return interp;
+ }
+
+ return NULL;
+}
+
/* Returns the current interpreter. */

struct ui_out *
@@ -467,15 +521,15 @@ static VEC (char_ptr) *
interpreter_completer (struct cmd_list_element *ignore,
const char *text, const char *word)
{
- struct ui_interp_info *ui_interp = get_current_interp_info ();
+ struct interp_factory *interp;
int textlen;
VEC (char_ptr) *matches = NULL;
- struct interp *interp;
+ int ix;

textlen = strlen (text);
- for (interp = ui_interp->interp_list;
- interp != NULL;
- interp = interp->next)
+ for (ix = 0;
+ VEC_iterate (interp_factory_p, interpreter_factories, ix, interp);
+ ++ix)
{
if (strncmp (interp->name, text, textlen) == 0)
{
diff --git a/gdb/interps.h b/gdb/interps.h
index f0badc5..f80e563 100644
--- a/gdb/interps.h
+++ b/gdb/interps.h
@@ -24,6 +24,13 @@

struct ui_out;
struct interp;
+struct ui;
+
+typedef struct interp *(*interp_factory_func) (const char *interp,
+ struct ui *ui);
+
+extern void interp_factory_register (const char *name,
+ interp_factory_func func);

extern int interp_resume (struct interp *interp);
extern int interp_suspend (struct interp *interp);
@@ -64,7 +71,9 @@ struct interp_procs
interp_command_loop_ftype *command_loop_proc;
};

-extern struct interp *interp_new (const char *name, const struct interp_procs *procs);
+extern struct interp *interp_new (const char *name,
+ const struct interp_procs *procs,
+ void *data);
extern void interp_add (struct interp *interp);
extern int interp_set (struct interp *interp, int top_level);
extern struct interp *interp_lookup (const char *name);
diff --git a/gdb/mi/mi-interp.c b/gdb/mi/mi-interp.c
index 7ec51d3..06f1ae8 100644
--- a/gdb/mi/mi-interp.c
+++ b/gdb/mi/mi-interp.c
@@ -1134,25 +1134,31 @@ mi_set_logging (struct interp *interp, int start_log,
return 1;
}

+static const struct interp_procs mi_interp_procs =
+{
+ mi_interpreter_init, /* init_proc */
+ mi_interpreter_resume, /* resume_proc */
+ mi_interpreter_suspend, /* suspend_proc */
+ mi_interpreter_exec, /* exec_proc */
+ mi_ui_out, /* ui_out_proc */
+ mi_set_logging, /* set_logging_proc */
+ mi_command_loop /* command_loop_proc */
+};
+
+static struct interp *
+mi_interp_factory (const char *name, struct ui *ui)
+{
+ return interp_new (name, &mi_interp_procs, NULL);
+}
+
extern initialize_file_ftype _initialize_mi_interp; /* -Wmissing-prototypes */

void
_initialize_mi_interp (void)
{
- static const struct interp_procs procs =
- {
- mi_interpreter_init, /* init_proc */
- mi_interpreter_resume, /* resume_proc */
- mi_interpreter_suspend, /* suspend_proc */
- mi_interpreter_exec, /* exec_proc */
- mi_ui_out, /* ui_out_proc */
- mi_set_logging, /* set_logging_proc */
- mi_command_loop /* command_loop_proc */
- };
-
/* The various interpreter levels. */
- interp_add (interp_new (INTERP_MI1, &procs));
- interp_add (interp_new (INTERP_MI2, &procs));
- interp_add (interp_new (INTERP_MI3, &procs));
- interp_add (interp_new (INTERP_MI, &procs));
+ interp_factory_register (INTERP_MI1, mi_interp_factory);
+ interp_factory_register (INTERP_MI2, mi_interp_factory);
+ interp_factory_register (INTERP_MI3, mi_interp_factory);
+ interp_factory_register (INTERP_MI, mi_interp_factory);
}
diff --git a/gdb/tui/tui-interp.c b/gdb/tui/tui-interp.c
index 7a0da48..c7910bc 100644
--- a/gdb/tui/tui-interp.c
+++ b/gdb/tui/tui-interp.c
@@ -138,6 +138,9 @@ tui_init (struct interp *self, int top_level)
/* Install exit handler to leave the screen in a good shape. */
atexit (tui_exit);

+ if (top_level)
+ tui_interp = self;
+
tui_initialize_static_data ();

tui_initialize_io ();
@@ -207,25 +210,30 @@ tui_exec (void *data, const char *command_str)
internal_error (__FILE__, __LINE__, _("tui_exec called"));
}

+static const struct interp_procs tui_interp_procs = {
+ tui_init,
+ tui_resume,
+ tui_suspend,
+ tui_exec,
+ tui_ui_out,
+ NULL,
+ cli_command_loop
+};
+
+static struct interp *
+tui_interp_factory (const char *name, struct ui *ui)
+{
+ return interp_new (name, &tui_interp_procs, NULL);
+}
+
/* Provide a prototype to silence -Wmissing-prototypes. */
extern initialize_file_ftype _initialize_tui_interp;

void
_initialize_tui_interp (void)
{
- static const struct interp_procs procs = {
- tui_init,
- tui_resume,
- tui_suspend,
- tui_exec,
- tui_ui_out,
- NULL,
- cli_command_loop
- };
-
- /* Create a default uiout builder for the TUI. */
- tui_interp = interp_new (INTERP_TUI, &procs);
- interp_add (tui_interp);
+ interp_factory_register (INTERP_TUI, tui_interp_factory);
+
if (interpreter_p && strcmp (interpreter_p, INTERP_TUI) == 0)
tui_start_enabled = 1;

--
2.5.0