[PATCH v3 26/34] Make main_ui be heap allocated

Pedro Alves
2016-05-06T12:45:04Z

This is preparation for being able to create more than one UI object.

The change to gdb_main to stop using catch_errors is necessary because
catch_errors references current_uiout, which expands to
current_ui->m_current_ui, which would crash because current_ui is not
initialized yet at that point. It didn't trigger earlier in the
series because before this patch, main_ui/current_ui always start out
non-NULL.

gdb/ChangeLog:
yyyy-mm-dd Pedro Alves <palves@redhat.com>

* event-top.c (main_ui_): Delete.
(main_ui, current_ui, ui_list): No longer initialize here.
* main.c (captured_main): UI initialization code factored out to
new new_ui function.
(gdb_main): Wrap captured_main with TRY/CATCH instead of
catch_errors.
* top.c (highest_ui_num): New global.
(new_ui): New function.
* top.h (struct ui) <num>: New field.
(new_ui): New declaration.
---
gdb/event-top.c | 9 ++++-----
gdb/main.c | 27 ++++++++++++---------------
gdb/top.c | 40 ++++++++++++++++++++++++++++++++++++++++
gdb/top.h | 6 ++++++
4 files changed, 62 insertions(+), 20 deletions(-)

diff --git a/gdb/event-top.c b/gdb/event-top.c
index c9e7548..318da1d 100644
--- a/gdb/event-top.c
+++ b/gdb/event-top.c
@@ -441,12 +441,11 @@ top_level_prompt (void)
return xstrdup (prompt);
}

-/* The main UI. */
-static struct ui main_ui_;
+/* See top.h. */

-struct ui *main_ui = &main_ui_;
-struct ui *current_ui = &main_ui_;
-struct ui *ui_list = &main_ui_;
+struct ui *main_ui;
+struct ui *current_ui;
+struct ui *ui_list;

/* See top.h. */

diff --git a/gdb/main.c b/gdb/main.c
index 541a077..8c9d563 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -443,7 +443,6 @@ DEF_VEC_O (cmdarg_s);
static int
captured_main (void *data)
{
- struct ui *ui = current_ui;
struct captured_main_args *context = (struct captured_main_args *) data;
int argc = context->argc;
char **argv = context->argv;
@@ -514,26 +513,15 @@ captured_main (void *data)

saved_command_line = (char *) xstrdup ("");

- ui->instream = stdin;
- ui->outstream = stdout;
- ui->errstream = stderr;
-
- ui->input_fd = fileno (stdin);
-
- ui->prompt_state = PROMPT_NEEDED;
-
#ifdef __MINGW32__
/* Ensure stderr is unbuffered. A Cygwin pty or pipe is implemented
as a Windows pipe, and Windows buffers on pipes. */
setvbuf (stderr, NULL, _IONBF, BUFSIZ);
#endif

- gdb_stdout = stdio_fileopen (stdout);
- gdb_stderr = stderr_fileopen (stderr);
+ main_ui = new_ui (stdin, stdout, stderr);
+ current_ui = main_ui;

- gdb_stdlog = gdb_stderr; /* for moment */
- gdb_stdtarg = gdb_stderr; /* for moment */
- gdb_stdin = stdio_fileopen (stdin);
gdb_stdtargerr = gdb_stderr; /* for moment */
gdb_stdtargin = gdb_stdin; /* for moment */

@@ -1174,7 +1162,16 @@ captured_main (void *data)
int
gdb_main (struct captured_main_args *args)
{
- catch_errors (captured_main, args, "", RETURN_MASK_ALL);
+ TRY
+ {
+ captured_main (args);
+ }
+ CATCH (ex, RETURN_MASK_ALL)
+ {
+ exception_print (gdb_stderr, ex);
+ }
+ END_CATCH
+
/* The only way to end up here is by an error (normal exit is
handled by quit_force()), hence always return an error status. */
return 1;
diff --git a/gdb/top.c b/gdb/top.c
index e40835b..c5e237d 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -246,6 +246,46 @@ void (*deprecated_call_command_hook) (struct cmd_list_element * c,

void (*deprecated_context_hook) (int id);

+/* The highest UI number ever assigned. */
+static int highest_ui_num;
+
+/* See top.h. */
+
+struct ui *
+new_ui (FILE *instream, FILE *outstream, FILE *errstream)
+{
+ struct ui *ui;
+
+ ui = XCNEW (struct ui);
+
+ ui->num = ++highest_ui_num;
+ ui->instream = instream;
+ ui->outstream = outstream;
+ ui->errstream = errstream;
+
+ ui->input_fd = fileno (ui->instream);
+
+ ui->m_gdb_stdin = stdio_fileopen (ui->instream);
+ ui->m_gdb_stdout = stdio_fileopen (ui->outstream);
+ ui->m_gdb_stderr = stderr_fileopen (ui->errstream);
+ ui->m_gdb_stdlog = ui->m_gdb_stderr;
+
+ ui->prompt_state = PROMPT_NEEDED;
+
+ if (ui_list == NULL)
+ ui_list = ui;
+ else
+ {
+ struct ui *last;
+
+ for (last = ui_list; last->next != NULL; last = last->next)
+ ;
+ last->next = ui;
+ }
+
+ return ui;
+}
+
/* Handler for SIGHUP. */

#ifdef SIGHUP
diff --git a/gdb/top.h b/gdb/top.h
index 092cc26..c933d6b 100644
--- a/gdb/top.h
+++ b/gdb/top.h
@@ -57,6 +57,9 @@ struct ui
/* Pointer to next in singly-linked list. */
struct ui *next;

+ /* Convenient handle (UI number). Unique across all UIs. */
+ int num;
+
/* The UI's command line buffer. This is to used to accumulate
input until we have a whole command line. */
struct buffer line_buffer;
@@ -170,6 +173,9 @@ extern void switch_thru_all_uis_next (struct switch_thru_all_uis *state);
#define ALL_UIS(UI) \
for (UI = ui_list; UI; UI = UI->next) \

+/* Create a new UI. */
+extern struct ui *new_ui (FILE *instream, FILE *outstream, FILE *errstream);
+
/* Cleanup that restores the current UI. */
extern void restore_ui_cleanup (void *data);

--
2.5.5