[PATCH v2 22/25] Make main_ui be heap allocated

[Pedro Alves <palves@redhat.com>]

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/event-top.c |  7 +++----
 gdb/main.c      | 27 ++++++++++++---------------
 gdb/top.c       | 37 +++++++++++++++++++++++++++++++++++++
 gdb/top.h       |  5 +++++
 4 files changed, 57 insertions(+), 19 deletions(-)

diff --git a/gdb/event-top.c b/gdb/event-top.c
index 436edf7..69f6be7 100644
--- a/gdb/event-top.c
+++ b/gdb/event-top.c
@@ -362,11 +362,10 @@ top_level_prompt (void)
   return xstrdup (prompt);
 }
 
-static struct ui main_ui_;
 
-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;
 
 void
 restore_ui_cleanup (void *data)
diff --git a/gdb/main.c b/gdb/main.c
index e107f60..95578e4 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -441,7 +441,6 @@ 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;
@@ -513,26 +512,15 @@ captured_main (void *data)
   clear_quit_flag ();
   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 */
 
@@ -1173,7 +1161,16 @@ 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 2941dbd..12064bc 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -245,6 +245,43 @@ void (*deprecated_call_command_hook) (struct cmd_list_element * c,
 
 void (*deprecated_context_hook) (int id);
 
+static int highest_ui_num;
+
+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 29deb3f..df76204 100644
--- a/gdb/top.h
+++ b/gdb/top.h
@@ -56,6 +56,9 @@ struct ui
 {
   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;
@@ -157,6 +160,8 @@ 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)		\
 
+extern struct ui *new_ui (FILE *instream, FILE *outstream, FILE *errstream);
+
 extern void restore_ui_cleanup (void *data);
 
 /* From top.c.  */
-- 
2.5.0