Re: [RFA] Fix osdata.c compile error without libexpat

[Pedro Alves <pedro at codesourcery dot com>]

On Tuesday 02 December 2008 13:37:20, teawater wrote:

> I got GDB-cvs build error if there is not libexpat.
> I found that osdata.c file doesn't define function "osdata_parse" if
> !defined(HAVE_LIBEXPAT). But in below, it is need.
> So I make a patch for it.

Thanks!  I'm applying this alternative patch below (that's a diff -upw),
which also fixes a few more issues I've found while relooking at this.

-- 
Pedro Alves

2008-12-02  Pedro Alves  <pedro@codesourcery.com>

	* target.h (target_get_osdata): Describe.
	* osdata.h (make_cleanup_osdata_free): Declare.
	* osdata.c (osdata_item_clear): Define even if HAVE_LIBEXPAT is
	not defined.
	(osdata_free_cleanup): New.
	(make_cleanup_osdata_free): New.
	(get_osdata): Fix leak.
	(info_osdata_command): Use make_cleanup_osdata_free.
	(info_processes_command): Delete.
	(_initialize_osdata): Drop undocumented "info processes" alias.
	* mi/mi-main.c (mi_cmd_list_thread_groups): Fix leak.

--- .pc/osdata.diff/gdb/target.h	2008-12-02 15:17:40.000000000 +0000
+++ gdb/target.h	2008-12-02 15:17:59.000000000 +0000
@@ -1286,6 +1286,12 @@ extern int target_resize_to_sections (st
 
 extern void remove_target_sections (bfd *abfd);
 
+/* Read OS data object of type TYPE from the target, and return it in
+   XML format.  The result is NUL-terminated and returned as a string,
+   allocated using xmalloc.  If an error occurs or the transfer is
+   unsupported, NULL is returned.  Empty objects are returned as
+   allocated but empty strings.  */
+
 extern char *target_get_osdata (const char *type);
 
 
--- .pc/osdata.diff/gdb/osdata.h	2008-12-02 15:17:40.000000000 +0000
+++ gdb/osdata.h	2008-12-02 15:17:59.000000000 +0000
@@ -46,6 +46,7 @@ DEF_VEC_P(osdata_p);
 
 struct osdata *osdata_parse (const char *xml);
 void osdata_free (struct osdata *);
+struct cleanup *make_cleanup_osdata_free (struct osdata *data);
 struct osdata *get_osdata (const char *type);
 const char *get_osdata_column (struct osdata_item *item, const char *name);
 
--- .pc/osdata.diff/gdb/osdata.c	2008-12-02 15:17:40.000000000 +0000
+++ gdb/osdata.c	2008-12-02 15:25:09.000000000 +0000
@@ -54,26 +54,6 @@ struct osdata_parsing_data
     char *property_name;
   };
 
-static void
-osdata_item_clear (struct osdata_item *item)
-{
-  if (item->columns != NULL)
-    {
-      struct osdata_column *col;
-      int ix;
-      for (ix = 0;
-          VEC_iterate (osdata_column_s, item->columns,
-                       ix, col);
-          ix++)
-       {
-         xfree (col->name);
-         xfree (col->value);
-       }
-      VEC_free (osdata_column_s, item->columns);
-      item->columns = NULL;
-    }
-}
-
 /* Handle the start of a <osdata> element.  */
 
 static void
@@ -205,6 +185,26 @@ osdata_parse (const char *xml)
 }
 #endif
 
+static void
+osdata_item_clear (struct osdata_item *item)
+{
+  if (item->columns != NULL)
+    {
+      struct osdata_column *col;
+      int ix;
+      for (ix = 0;
+	   VEC_iterate (osdata_column_s, item->columns,
+			ix, col);
+	   ix++)
+       {
+	 xfree (col->name);
+	 xfree (col->value);
+       }
+      VEC_free (osdata_column_s, item->columns);
+      item->columns = NULL;
+    }
+}
+
 void
 osdata_free (struct osdata *osdata)
 {
@@ -226,16 +226,34 @@ osdata_free (struct osdata *osdata)
   xfree (osdata);
 }
 
-struct osdata *get_osdata (const char *type)
+static void
+osdata_free_cleanup (void *arg)
+{
+  struct osdata *osdata = arg;
+  osdata_free (osdata);
+}
+
+struct cleanup *
+make_cleanup_osdata_free (struct osdata *data)
+{
+  return make_cleanup (osdata_free_cleanup, data);
+}
+
+struct osdata *
+get_osdata (const char *type)
 {
   struct osdata * osdata = NULL;
   char *xml = target_get_osdata (type);
   if (xml)
     {
+      struct cleanup *old_chain = make_cleanup (xfree, xml);
+
       if (xml[0] == '\0')
 	warning (_("Empty data returned by target.  Wrong osdata type?"));
-      
+      else
       osdata = osdata_parse (xml);
+
+      do_cleanups (old_chain);
     }
   
   if (!osdata)
@@ -264,8 +282,8 @@ void
 info_osdata_command (char *type, int from_tty)
 {
   struct osdata * osdata = NULL;
-  struct cleanup *proc_tbl_chain;
   struct osdata_item *last;
+  struct cleanup *old_chain;
   int ncols;
   int nprocs;
 
@@ -274,6 +292,7 @@ info_osdata_command (char *type, int fro
     error (_("Argument required."));
 
   osdata = get_osdata (type);
+  old_chain = make_cleanup_osdata_free (osdata);
 
   nprocs = VEC_length (osdata_item_s, osdata->items);
 
@@ -283,8 +302,7 @@ info_osdata_command (char *type, int fro
   else
     ncols = 0;
 
-  proc_tbl_chain
-    = make_cleanup_ui_out_table_begin_end (uiout, ncols, nprocs,
+  make_cleanup_ui_out_table_begin_end (uiout, ncols, nprocs,
                                           "OSDataTable");
 
   if (last && last->columns)
@@ -310,14 +328,14 @@ info_osdata_command (char *type, int fro
                        ix_items, item);
           ix_items++)
        {
-         struct cleanup *old_chain, *chain;
+         struct cleanup *old_chain;
          struct ui_stream *stb;
          int ix_cols;
          struct osdata_column *col;
 
          stb = ui_out_stream_new (uiout);
          old_chain = make_cleanup_ui_out_stream_delete (stb);
-         chain = make_cleanup_ui_out_tuple_begin_end (uiout, "item");
+         make_cleanup_ui_out_tuple_begin_end (uiout, "item");
 
          for (ix_cols = 0;
               VEC_iterate (osdata_column_s, item->columns,
@@ -325,22 +343,13 @@ info_osdata_command (char *type, int fro
               ix_cols++)
            ui_out_field_string (uiout, col->name, col->value);
 
-         do_cleanups (chain);
          do_cleanups (old_chain);
 
          ui_out_text (uiout, "\n");
        }
     }
 
-  do_cleanups (proc_tbl_chain);
-
-  osdata_free (osdata);
-}
-
-static void
-info_processes_command (char *args, int from_tty)
-{
-  info_osdata_command ("processes", from_tty);
+  do_cleanups (old_chain);
 }
 
 extern initialize_file_ftype _initialize_osdata; /* -Wmissing-prototypes */
@@ -350,8 +359,4 @@ _initialize_osdata (void)
 {
   add_info ("os", info_osdata_command,
            _("Show OS data ARG."));
-
-  /* An alias for "info osdata processes".  */
-  add_info ("processes", info_processes_command,
-           _("List running processes on the target."));
 }
--- .pc/osdata.diff/gdb/mi/mi-main.c	2008-12-02 15:17:40.000000000 +0000
+++ gdb/mi/mi-main.c	2008-12-02 15:22:06.000000000 +0000
@@ -377,7 +377,7 @@ mi_cmd_list_thread_groups (char *command
   if (argc > 0)
     id = argv[0];
 
-  back_to = make_cleanup (&null_cleanup, NULL);
+  back_to = make_cleanup (null_cleanup, NULL);
 
   if (available && id)
     {
@@ -385,10 +385,13 @@ mi_cmd_list_thread_groups (char *command
     }
   else if (available)
     {
-      struct osdata *data = get_osdata ("processes");
+      struct osdata *data;
       struct osdata_item *item;
       int ix_items;
 
+      data = get_osdata ("processes");
+      make_cleanup_osdata_free (data);
+
       make_cleanup_ui_out_list_begin_end (uiout, "groups");
       
       for (ix_items = 0;