[PATCH] Delete program spaces directly when removing inferiors

[Simon Marchi <simon dot marchi at ericsson dot com>]

When deleting an inferior, delete the associated program space as well
if it becomes unused. This replaces the "pruning" approach, with which
you could forget to call prune_program_spaces (as seen, with the
-remove-inferior command, see [1]).

This allows to remove the prune_program_spaces function. At the same
time, I was able to clean up the delete_inferior* family.
delete_inferior_silent and delete_inferior were unused, which allowed
renaming delete_inferior_1 to delete_inferior. Also, since all calls to
it were with silent=1, I removed that parameter completely.

I renamed pspace_empty_p to program_space_empty_p. I prefer if the
"exported" functions have a more explicit and standard name.

Tested on Ubuntu 14.10.

This obsoletes my previous patch "Add call to prune_program_spaces in
mi_cmd_remove_inferior" [1].

[1] https://sourceware.org/ml/gdb-patches/2014-09/msg00717.html

(err... it's the first time one of my patches has such a "big" Changelog,
I feel like I am forgetting something.)

gdb/Changelog:

	* inferior.c (delete_inferior_1): Rename to ...
	(delete_inferior): ..., remove 'silent' parameter, delete
	program space when unused and remove call to prune_program_spaces.
	Remove the old, unused, delete_inferior.
	(delete_inferior_silent): Remove.
	(prune_inferiors): Change call from delete_inferior_1 to
	delete_inferior and remove 'silent' parameter. Remove call to
	prune_program_spaces.
	(remove_inferior_command): Idem.
	* inferior.h (delete_inferior_1): Rename to...
	(delete_inferior): ..., remove 'silent' parameter and remove the
	original delete_inferior.
	(delete_inferior_silent): Remove.
	* mi/mi-main.c (mi_cmd_remove_inferior): Change call from
	delete_inferior_1 to delete_inferior and remove 'silent'
	parameter.
	* progspace.c (prune_program_spaces): Remove.
	(pspace_empty_p): Rename to...
	(program_space_empty_p): ... and make non-static.
	(delete_program_space): New.
	* progspace.h (prune_program_spaces): Remove declaration.
	(program_space_empty_p): New declaration.
	(delete_program_space): New declaration.
---
 gdb/inferior.c   | 39 ++++++++-------------------------------
 gdb/inferior.h   |  9 +--------
 gdb/mi/mi-main.c |  2 +-
 gdb/progspace.c  | 38 ++++++++++++++++++++------------------
 gdb/progspace.h  | 11 +++++++----
 5 files changed, 37 insertions(+), 62 deletions(-)

diff --git a/gdb/inferior.c b/gdb/inferior.c
index 23da0c7..df33845 100644
--- a/gdb/inferior.c
+++ b/gdb/inferior.c
@@ -184,11 +184,8 @@ delete_thread_of_inferior (struct thread_info *tp, void *data)
   return 0;
 }
 
-/* If SILENT then be quiet -- don't announce a inferior death, or the
-   exit of its threads.  */
-
 void
-delete_inferior_1 (struct inferior *todel, int silent)
+delete_inferior (struct inferior *todel)
 {
   struct inferior *inf, *infprev;
   struct delete_thread_of_inferior_arg arg;
@@ -203,7 +200,7 @@ delete_inferior_1 (struct inferior *todel, int silent)
     return;
 
   arg.pid = inf->pid;
-  arg.silent = silent;
+  arg.silent = 1;
 
   iterate_over_threads (delete_thread_of_inferior, &arg);
 
@@ -214,29 +211,13 @@ delete_inferior_1 (struct inferior *todel, int silent)
 
   observer_notify_inferior_removed (inf);
 
-  free_inferior (inf);
-}
-
-void
-delete_inferior (int pid)
-{
-  struct inferior *inf = find_inferior_pid (pid);
-
-  delete_inferior_1 (inf, 0);
-
-  if (print_inferior_events)
-    printf_unfiltered (_("[Inferior %d exited]\n"), pid);
-}
+  /* If this program space is rendered useless, remove it. */
+  if (program_space_empty_p (inf->pspace))
+      delete_program_space (inf->pspace);
 
-void
-delete_inferior_silent (int pid)
-{
-  struct inferior *inf = find_inferior_pid (pid);
-
-  delete_inferior_1 (inf, 1);
+  free_inferior (inf);
 }
 
-
 /* If SILENT then be quiet -- don't announce a inferior exit, or the
    exit of its threads.  */
 
@@ -498,11 +479,9 @@ prune_inferiors (void)
 	}
 
       *ss_link = ss->next;
-      delete_inferior_1 (ss, 1);
+      delete_inferior (ss);
       ss = *ss_link;
     }
-
-  prune_program_spaces ();
 }
 
 /* Simply returns the count of inferiors.  */
@@ -786,10 +765,8 @@ remove_inferior_command (char *args, int from_tty)
 	  continue;
 	}
 
-      delete_inferior_1 (inf, 1);
+      delete_inferior (inf);
     }
-
-  prune_program_spaces ();
 }
 
 struct inferior *
diff --git a/gdb/inferior.h b/gdb/inferior.h
index 58557a4..67bc989 100644
--- a/gdb/inferior.h
+++ b/gdb/inferior.h
@@ -426,14 +426,7 @@ extern struct inferior *add_inferior (int pid);
    the CLI.  */
 extern struct inferior *add_inferior_silent (int pid);
 
-/* Delete an existing inferior list entry, due to inferior exit.  */
-extern void delete_inferior (int pid);
-
-extern void delete_inferior_1 (struct inferior *todel, int silent);
-
-/* Same as delete_inferior, but don't print new inferior notifications
-   to the CLI.  */
-extern void delete_inferior_silent (int pid);
+extern void delete_inferior (struct inferior *todel);
 
 /* Delete an existing inferior list entry, due to inferior detaching.  */
 extern void detach_inferior (int pid);
diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
index 59717ca..5d69fc7 100644
--- a/gdb/mi/mi-main.c
+++ b/gdb/mi/mi-main.c
@@ -1950,7 +1950,7 @@ mi_cmd_remove_inferior (char *command, char **argv, int argc)
       set_current_program_space (new_inferior->pspace);
     }
 
-  delete_inferior_1 (inf, 1 /* silent */);
+  delete_inferior (inf);
 }
 
 
diff --git a/gdb/progspace.c b/gdb/progspace.c
index b111a50..33ae6ae 100644
--- a/gdb/progspace.c
+++ b/gdb/progspace.c
@@ -235,8 +235,8 @@ save_current_program_space (void)
 
 /* Returns true iff there's no inferior bound to PSPACE.  */
 
-static int
-pspace_empty_p (struct program_space *pspace)
+int
+program_space_empty_p (struct program_space *pspace)
 {
   if (find_inferior_for_program_space (pspace) != NULL)
       return 0;
@@ -244,30 +244,32 @@ pspace_empty_p (struct program_space *pspace)
   return 1;
 }
 
-/* Prune away automatically added program spaces that aren't required
-   anymore.  */
+/* Remove a program space from the program spaces list and release it.  It is
+   an error to call this function while PSPACE is the current program space. */
 
 void
-prune_program_spaces (void)
+delete_program_space (struct program_space *pspace)
 {
-  struct program_space *ss, **ss_link;
-  struct program_space *current = current_program_space;
+  gdb_assert(pspace != NULL);
+  gdb_assert(pspace != current_program_space);
 
-  ss = program_spaces;
-  ss_link = &program_spaces;
-  while (ss)
+  if (pspace == program_spaces)
+    program_spaces = pspace->next;
+  else
     {
-      if (ss == current || !pspace_empty_p (ss))
+      struct program_space *i = program_spaces;
+
+      for (i = program_spaces; i != NULL; i = i->next)
 	{
-	  ss_link = &ss->next;
-	  ss = *ss_link;
-	  continue;
+	  if (i->next == pspace)
+	    {
+	      i->next = i->next->next;
+	      break;
+	    }
 	}
-
-      *ss_link = ss->next;
-      release_program_space (ss);
-      ss = *ss_link;
     }
+
+  release_program_space (pspace);
 }
 
 /* Prints the list of program spaces and their details on UIOUT.  If
diff --git a/gdb/progspace.h b/gdb/progspace.h
index 08e04eb..8beebd8 100644
--- a/gdb/progspace.h
+++ b/gdb/progspace.h
@@ -236,9 +236,16 @@ extern struct program_space *current_program_space;
    pointer to the new object.  */
 extern struct program_space *add_program_space (struct address_space *aspace);
 
+/* Remove a program space from the program spaces list and release it.  It is
+   an error to call this function while PSPACE is the current program space. */
+extern void delete_program_space (struct program_space *pspace);
+
 /* Returns the number of program spaces listed.  */
 extern int number_of_program_spaces (void);
 
+/* Returns true iff there's no inferior bound to PSPACE.  */
+extern int program_space_empty_p (struct program_space *pspace);
+
 /* Copies program space SRC to DEST.  Copies the main executable file,
    and the main symbol file.  Returns DEST.  */
 extern struct program_space *clone_program_space (struct program_space *dest,
@@ -288,10 +295,6 @@ extern int address_space_num (struct address_space *aspace);
    mappings.  */
 extern void update_address_spaces (void);
 
-/* Prune away automatically added program spaces that aren't required
-   anymore.  */
-extern void prune_program_spaces (void);
-
 /* Reset saved solib data at the start of an solib event.  This lets
    us properly collect the data when calling solib_add, so it can then
    later be printed.  */
-- 
2.1.0