Bug with lists in tables in ui-out.c

[Jim Ingham <jingham at apple dot com>]

Hi all,

Turns out if you have an element of a table that is a list or tuple, then
the current ui-out table code chokes.  verify_field_alignment doesn't know
that each of the elements of the sublist are not separate table elements, so
it throws an error at the first one it sees.  The following patch fixes this
bug.  

Note that in the FSF gdb code, no one ever uses this feature, because the
only client of the ui_out_table is the breakpoint printer, and it cleverly
only declares the first 5 or 6 columns of the breakpoint info table in the
table header, and sticks on the rest of the info as undeclared freebies
(which is kind of lame, but another story...), so the commands, which are a
list, don't get added to the table proper, and thus don't trip the bug.

I have a patch which will fix this and make the table header accurate, but I
am not submitting it here because (a) it is a separate issue and (b) it will
change the output of the "info breakpoint" command (though only the header),
and so may not necessarily please everyone...

Jim

Index: ui-out.c
===================================================================
RCS file: /cvs/src/src/gdb/ui-out.c,v
retrieving revision 1.18
diff -p -r1.18 ui-out.c
*** ui-out.c    2001/07/06 03:53:11     1.18
--- ui-out.c    2001/11/29 01:40:59
*************** ui_out_end (struct ui_out *uiout,
*** 367,372 ****
--- 367,384 ----
            enum ui_out_type type)
  {
    int old_level = pop_level (uiout, type);
+ 
+   /* If we are building up a table, and we were making a table element
+      which was a list or tuple, then when we end the list, we have to
+      increment the header. Watch out, however, the current breakpoint
+      code actually emits more columns than it defines in the header
+      so we have to be careful not to walk off the end. */
+ 
+   if (uiout->table_flag && uiout->body_flag
+       && uiout->level == 1
+       && uiout->headercurr != NULL)
+     uiout->headercurr = uiout->headercurr->next;
+   
    uo_end (uiout, type, old_level);
  }
  
*************** append_header_to_list (struct ui_out *ui
*** 1018,1024 ****
    uiout->headercurr = uiout->headerlast;
  }
  
! /* returns 0 if there is no more headers */
  
  static int
  get_curr_header (struct ui_out *uiout,
--- 1030,1038 ----
    uiout->headercurr = uiout->headerlast;
  }
  
! /* Returns information on the current header.  ALSO Increments the
!    current header in UI_OUT.  Returns 0 if there is no more headers, 1
!    otherwise. */
  
  static int
  get_curr_header (struct ui_out *uiout,
*************** specified after table_body and inside a
*** 1056,1062 ****
      }
  }
  
! /* determines what is the alignment policy */
  
  static void
  verify_field_alignment (struct ui_out *uiout,
--- 1070,1079 ----
      }
  }
  
! /* Determines what is the alignment policy.  NB: as a side-effect of
!  calling get_curr_header, this also increments the current header.  So
!  you have to call verify_field_alignment in any call that adds a
!  complete bit of data to a table column. */
  
  static void
  verify_field_alignment (struct ui_out *uiout,
*************** verify_field_alignment (struct ui_out *u
*** 1066,1073 ****
  {
    int colno;
    char *text;
  
!   if (uiout->table_flag
        && get_curr_header (uiout, &colno, width, align, &text))
      {
        if (fldno != colno)
--- 1083,1097 ----
  {
    int colno;
    char *text;
+ 
+   /* Be careful - if you are building up a list or tuple AS AN ELEMENT
+      of a table, you don't want to call get_curr_header, since that will
+      increment the current header, which would be wrong. Currently, tables
+      can only be built at level 1, so I am using that as a check.  If this
+      stuff is ever generalized, we will need to stuff the level of the
+      current table into the (putative) ui_table structure. */
  
!   if (uiout->table_flag && uiout->level == 1
        && get_curr_header (uiout, &colno, width, align, &text))
      {
        if (fldno != colno)

-- 
+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==
Jim Ingham                              jingham@apple.com
Developer Tools - gdb