Non bit-packed packed arrays as variable-length fields

In the case of non bit-packed arrays, GNAT does not generate its
traditional XP encoding; it is not needed. However, it still generates
the so-called "implementation type" with a P suffix. This
implementation type shall be skipped when looking for other
descriptive types such as XA encodings for variable-length
fields.

Note also that there may be an intermediate typedef between the
implementation type and its XA description. It shall be skipped
as well.

gdb/ChangeLog:

        Jerome Guitton  <guitton@adacore.com>
	* ada-lang.c (find_parallel_type_by_descriptive_type):
	Go through typedefs during lookup.
	(to_fixed_array_type): Add support for non-bit packed arrays
	as variable-length fields.

gdb/testsuite/ChangeLog:

        * gdb.ada/byte_packed_arr: New testcase.

gdb/ChangeLog

@@ -1,3 +1,10 @@
+2015-05-15  Jerome Guitton  <guitton@adacore.com>
+
+	* ada-lang.c (find_parallel_type_by_descriptive_type):
+	Go through typedefs during lookup.
+	(to_fixed_array_type): Add support for non-bit packed arrays
+	as variable-length fields.
+
 2015-05-15  Pedro Alves  <palves@redhat.com>
 	    Simon Marchi  <simon.marchi@ericsson.com>
 

gdb/ada-lang.c

@@ -7762,7 +7762,7 @@ ada_type_name (struct type *type)
 static struct type *
 find_parallel_type_by_descriptive_type (struct type *type, const char *name)
 {
-  struct type *result;
+  struct type *result, *tmp;
 
   if (ada_ignore_descriptive_types_p)
     return NULL;
@@ -7789,9 +7789,21 @@ find_parallel_type_by_descriptive_type (struct type *type, const char *name)
 
       /* Otherwise, look at the next item on the list, if any.  */
       if (HAVE_GNAT_AUX_INFO (result))
-	result = TYPE_DESCRIPTIVE_TYPE (result);
+	tmp = TYPE_DESCRIPTIVE_TYPE (result);
       else
-	result = NULL;
+	tmp = NULL;
+
+      /* If not found either, try after having resolved the typedef.  */
+      if (tmp != NULL)
+	result = tmp;
+      else
+	{
+	  CHECK_TYPEDEF (result);
+	  if (HAVE_GNAT_AUX_INFO (result))
+	    result = TYPE_DESCRIPTIVE_TYPE (result);
+	  else
+	    result = NULL;
+	}
     }
 
   /* If we didn't find a match, see whether this is a packed array.  With
@@ -8509,6 +8521,7 @@ to_fixed_array_type (struct type *type0, struct value *dval,
   struct type *index_type_desc;
   struct type *result;
   int constrained_packed_array_p;
+  static const char *xa_suffix = "___XA";
 
   type0 = ada_check_typedef (type0);
   if (TYPE_FIXED_INSTANCE (type0))
@@ -8518,7 +8531,30 @@ to_fixed_array_type (struct type *type0, struct value *dval,
   if (constrained_packed_array_p)
     type0 = decode_constrained_packed_array_type (type0);
 
-  index_type_desc = ada_find_parallel_type (type0, "___XA");
+  index_type_desc = ada_find_parallel_type (type0, xa_suffix);
+
+  /* As mentioned in exp_dbug.ads, for non bit-packed arrays an
+     encoding suffixed with 'P' may still be generated.  If so,
+     it should be used to find the XA type.  */
+
+  if (index_type_desc == NULL)
+    {
+      const char *typename = ada_type_name (type0);
+
+      if (typename != NULL)
+	{
+	  const int len = strlen (typename);
+	  char *name = (char *) alloca (len + strlen (xa_suffix));
+
+	  if (typename[len - 1] == 'P')
+	    {
+	      strcpy (name, typename);
+	      strcpy (name + len - 1, xa_suffix);
+	      index_type_desc = ada_find_parallel_type_with_name (type0, name);
+	    }
+	}
+    }
+
   ada_fixup_array_indexes_type (index_type_desc);
   if (index_type_desc != NULL
       && ada_is_redundant_index_type_desc (type0, index_type_desc))

gdb/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2015-05-15  Joel Brobecker  <brobecker@adacore.com>
+
+	* gdb.ada/byte_packed_arr: New testcase.
+
 2015-05-15  Joel Brobecker  <brobecker@adacore.com>
 
 	* gdb.ada/pckd_neg: New testcase.

gdb/testsuite/gdb.ada/byte_packed_arr.exp

@@ -0,0 +1,32 @@
+# Copyright 2015 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+load_lib "ada.exp"
+
+if { [skip_ada_tests] } { return -1 }
+
+standard_ada_testfile reprod_main
+
+if {[gdb_compile_ada "${srcfile}" "${binfile}" executable {debug}] != ""} {
+    return -1
+}
+
+clean_restart ${testfile}
+
+set bp_location [gdb_get_line_number "STOP" ${testdir}/reprod.adb]
+runto "reprod.adb:$bp_location"
+
+gdb_test "print broken" \
+         " = \\(len => 1, data => \\(\\(i => 1\\)\\)\\)"

gdb/testsuite/gdb.ada/byte_packed_arr/array_list_g.ads

@@ -0,0 +1,27 @@
+--  Copyright 2015 Free Software Foundation, Inc.
+--
+--  This program is free software; you can redistribute it and/or modify
+--  it under the terms of the GNU General Public License as published by
+--  the Free Software Foundation; either version 3 of the License, or
+--  (at your option) any later version.
+--
+--  This program is distributed in the hope that it will be useful,
+--  but WITHOUT ANY WARRANTY; without even the implied warranty of
+--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+--  GNU General Public License for more details.
+--
+--  You should have received a copy of the GNU General Public License
+--  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+generic
+  type Index_Base_T is range <>;
+  type Component_T is private;
+package Array_List_G is
+
+  subtype Length_T is Index_Base_T range 0 .. Index_Base_T'Last;
+  subtype Index_T is Length_T range 1 .. Length_T'Last;
+
+  type T is array (Index_T range <>) of Component_T;
+  pragma Pack(T);
+
+end Array_List_G;

gdb/testsuite/gdb.ada/byte_packed_arr/reprod.adb

@@ -0,0 +1,22 @@
+--  Copyright 2015 Free Software Foundation, Inc.
+--
+--  This program is free software; you can redistribute it and/or modify
+--  it under the terms of the GNU General Public License as published by
+--  the Free Software Foundation; either version 3 of the License, or
+--  (at your option) any later version.
+--
+--  This program is distributed in the hope that it will be useful,
+--  but WITHOUT ANY WARRANTY; without even the implied warranty of
+--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+--  GNU General Public License for more details.
+--
+--  You should have received a copy of the GNU General Public License
+--  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package body Reprod is
+
+   procedure Do_Nothing (Broken : Obj_T) is
+   begin
+      null; --  STOP
+   end Do_Nothing;
+end Reprod;

gdb/testsuite/gdb.ada/byte_packed_arr/reprod.ads

@@ -0,0 +1,35 @@
+--  Copyright 2015 Free Software Foundation, Inc.
+--
+--  This program is free software; you can redistribute it and/or modify
+--  it under the terms of the GNU General Public License as published by
+--  the Free Software Foundation; either version 3 of the License, or
+--  (at your option) any later version.
+--
+--  This program is distributed in the hope that it will be useful,
+--  but WITHOUT ANY WARRANTY; without even the implied warranty of
+--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+--  GNU General Public License for more details.
+--
+--  You should have received a copy of the GNU General Public License
+--  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+with Array_List_G;
+
+package Reprod is
+
+   package Objects is
+      type T is record
+         I : Integer;
+      end record;
+      package List is new Array_List_G (Index_Base_T => Natural,
+                                        Component_T => T);
+   end Objects;
+
+   type Obj_T (Len : Natural) is record
+      Data : Objects.List.T (1 .. Len);
+   end record;
+
+   type T is access Obj_T;
+
+   procedure Do_Nothing (Broken : Obj_T);
+end Reprod;

gdb/testsuite/gdb.ada/byte_packed_arr/reprod_main.adb

@@ -0,0 +1,23 @@
+--  Copyright 2015 Free Software Foundation, Inc.
+--
+--  This program is free software; you can redistribute it and/or modify
+--  it under the terms of the GNU General Public License as published by
+--  the Free Software Foundation; either version 3 of the License, or
+--  (at your option) any later version.
+--
+--  This program is distributed in the hope that it will be useful,
+--  but WITHOUT ANY WARRANTY; without even the implied warranty of
+--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+--  GNU General Public License for more details.
+--
+--  You should have received a copy of the GNU General Public License
+--  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+with Reprod; use Reprod;
+
+procedure Reprod_Main is
+   O : Obj_T (Len => 1);
+begin
+   O.Data := (others => (I => 1));
+   Do_Nothing (O);
+end Reprod_Main;