[commit/Ada] "info tasks" broken by typedefs in ATCB type definitions.

[Joel Brobecker <brobecker at adacore dot com>]

From: botcazou <botcazou@f8352e7e-cb20-0410-8ce7-b5d9e71c585c>

Eric made a change in the compiler in Aug 2009 that uncovered a hole
in the way the debugger builds the type structures it then uses to
compute the Ada tasking info.  The change itself was described by
Eric as follow:

> This change is aimed at unifying how pointers to
> unconstrained arrays are represented in the debug info, but this apparently
> exhibits a problem in the way ada-tasks.c builds the type of the ATCB.
>
> What has changed in the type of the fields "entry_names" and "open_accepts".
> They were duplicates of entry_names_array___XUP and accept_list___XUP
> respectively, now they are references to them through a DW_TAG_typedef
> [...]

In practice, we would get warnings, and often invalid data (due to
the wrong values being fetched):

    (gdb) info tasks
    warning: array or string index out of range
    warning: array or string index out of range
    warning: array or string index out of range
      ID       TID P-ID Pri State                  Name
       1    642010    0  48 Child Termination Wait main_task
       2    642d20    1  48 Accept or Select Term  my_callee
    *  3    646400    1  48 Runnable               my_caller

Eric fixed the problem with the following patch.

gdb/ChangeLog:

        "info tasks" broken by typedefs in ATCB type definitions.
	* ada-lang.c (ada_template_to_fixed_record_type_1): Add call to
	ada_check_typedef before retrieving the length of the type for
	regular fields.

Tested on x86_64-linux. Checked in.

---
 gdb/ada-lang.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 8f90711..2f16644 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -6929,14 +6929,16 @@ ada_template_to_fixed_record_type_1 (struct type *type,
         }
       else
         {
-          TYPE_FIELD_TYPE (rtype, f) = TYPE_FIELD_TYPE (type, f);
+          struct type *field_type = TYPE_FIELD_TYPE (type, f);
+
+          TYPE_FIELD_TYPE (rtype, f) = field_type;
           TYPE_FIELD_NAME (rtype, f) = TYPE_FIELD_NAME (type, f);
           if (TYPE_FIELD_BITSIZE (type, f) > 0)
             bit_incr = fld_bit_len =
               TYPE_FIELD_BITSIZE (rtype, f) = TYPE_FIELD_BITSIZE (type, f);
           else
             bit_incr = fld_bit_len =
-              TYPE_LENGTH (TYPE_FIELD_TYPE (type, f)) * TARGET_CHAR_BIT;
+              TYPE_LENGTH (ada_check_typedef (field_type)) * TARGET_CHAR_BIT;
         }
       if (off + fld_bit_len > bit_len)
         bit_len = off + fld_bit_len;
-- 
1.6.3.3