[Ada] Pointers to unconstrained arrays inside variant record.

gdb/ChangeLog:

        * ada-lang.c (ada_template_to_fixed_record_type_1): Do not
        strip typedef layer when computing the fixed type's field type,
        only when computing its size.

gdb/testsuite/ChangeLog:

        * gdb.ada/unc_arr_ptr_in_var_rec: New testcase.

7 files changed, 209 insertions, 14 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index b5b0cbccf90..6f2fb0c1d6d 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2012-10-24  Joel Brobecker  <brobecker@adacore.com>
+
+	* ada-lang.c (ada_template_to_fixed_record_type_1): Do not
+	strip typedef layer when computing the fixed type's field type,
+	only when computing its size.
+
 2012-10-24  Mark Kettenis  <kettenis@gnu.org>
 
 	PR gdb/12783
diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index f45815f7686..9f329df0cd2 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -7504,25 +7504,35 @@ ada_template_to_fixed_record_type_1 (struct type *type,
         }
       else
         {
-          struct type *field_type = TYPE_FIELD_TYPE (type, f);
-
-	  /* If our field is a typedef type (most likely a typedef of
-	     a fat pointer, encoding an array access), then we need to
-	     look at its target type to determine its characteristics.
-	     In particular, we would miscompute the field size if we took
-	     the size of the typedef (zero), instead of the size of
-	     the target type.  */
-	  if (TYPE_CODE (field_type) == TYPE_CODE_TYPEDEF)
-	    field_type = ada_typedef_target_type (field_type);
-
-          TYPE_FIELD_TYPE (rtype, f) = field_type;
+	  /* Note: If this field's type is a typedef, it is important
+	     to preserve the typedef layer.
+
+	     Otherwise, we might be transforming a typedef to a fat
+	     pointer (encoding a pointer to an unconstrained array),
+	     into a basic fat pointer (encoding an unconstrained
+	     array).  As both types are implemented using the same
+	     structure, the typedef is the only clue which allows us
+	     to distinguish between the two options.  Stripping it
+	     would prevent us from printing this field appropriately.  */
+          TYPE_FIELD_TYPE (rtype, f) = TYPE_FIELD_TYPE (type, f);
           TYPE_FIELD_NAME (rtype, f) = TYPE_FIELD_NAME (type, f);
           if (TYPE_FIELD_BITSIZE (type, f) > 0)
             fld_bit_len =
               TYPE_FIELD_BITSIZE (rtype, f) = TYPE_FIELD_BITSIZE (type, f);
           else
-            fld_bit_len =
-              TYPE_LENGTH (ada_check_typedef (field_type)) * TARGET_CHAR_BIT;
+	    {
+	      struct type *field_type = TYPE_FIELD_TYPE (type, f);
+
+	      /* We need to be careful of typedefs when computing
+		 the length of our field.  If this is a typedef,
+		 get the length of the target type, not the length
+		 of the typedef.  */
+	      if (TYPE_CODE (field_type) == TYPE_CODE_TYPEDEF)
+		field_type = ada_typedef_target_type (field_type);
+
+              fld_bit_len =
+                TYPE_LENGTH (ada_check_typedef (field_type)) * TARGET_CHAR_BIT;
+	    }
         }
       if (off + fld_bit_len > bit_len)
         bit_len = off + fld_bit_len;
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index e4f5657ff41..a7a11803651 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2012-10-24  Joel Brobecker  <brobecker@adacore.com>
+
+	* gdb.ada/unc_arr_ptr_in_var_rec: New testcase.
+
 2012-10-24  Mark Kettenis  <kettenis@gnu.org>
 
 	* gdb.base/callfuncs.exp: PR gdb/12783 is now fixed.
diff --git a/gdb/testsuite/gdb.ada/unc_arr_ptr_in_var_rec.exp b/gdb/testsuite/gdb.ada/unc_arr_ptr_in_var_rec.exp
new file mode 100644
index 00000000000..dc9e86319df
--- /dev/null
+++ b/gdb/testsuite/gdb.ada/unc_arr_ptr_in_var_rec.exp
@@ -0,0 +1,84 @@
+# Copyright 2012 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"
+
+standard_ada_testfile foo
+
+if {[gdb_compile_ada "${srcfile}" "${binfile}" executable [list debug]] != "" } {
+  return -1
+}
+
+clean_restart ${testfile}
+
+set bp_location [gdb_get_line_number "STOP1" ${testdir}/foo.adb]
+runto "foo.adb:$bp_location"
+
+# Print My_Object and My_Object.Ptr when Ptr is null...
+
+gdb_test "print my_object" \
+         "= \\(n => 3, ptr => 0x0, data => \\(3, 5, 8\\)\\)" \
+         "print My_Object with null Ptr"
+
+gdb_test "print my_object.ptr" \
+         "= \\(foo.table_access\\) 0x0" \
+         "print My_Object.Ptr when null"
+
+# Same for My_P_Object...
+
+gdb_test "print my_p_object" \
+         "= \\(n => 3, ptr => 0x0, data => \\(3, 5, 8\\)\\)" \
+         "print My_P_Object with null Ptr"
+
+gdb_test "print my_p_object.ptr" \
+         "\\(foo.p_table_access\\) 0x0" \
+         "print My_P_Object.Ptr when null"
+
+# Continue until the Ptr component of both objects get allocated.
+
+set bp_location [gdb_get_line_number "STOP2" ${testdir}/foo.adb]
+
+gdb_breakpoint "foo.adb:$bp_location"
+
+gdb_test "continue" \
+         "Breakpoint $decimal, foo \\(\\) at .*foo.adb:$decimal.*" \
+         "continue to STOP2"
+
+# Inspect My_Object again...
+
+gdb_test "print my_object" \
+         "= \\(n => 3, ptr => $hex, data => \\(3, 5, 8\\)\\)" \
+         "print my_object after setting Ptr"
+
+gdb_test "print my_object.ptr" \
+         "\\(foo.table_access\\) $hex" \
+         "print My_P_Object.Ptr when no longer null"
+
+gdb_test "print my_object.ptr.all" \
+         "= \\(13, 21, 34\\)"
+
+# Same with My_P_Object...
+
+gdb_test "print my_p_object" \
+         "= \\(n => 3, ptr => $hex, data => \\(3, 5, 8\\)\\)" \
+         "print my_p_object after setting Ptr"
+
+gdb_test "print my_p_object.ptr" \
+         "= \\(foo.p_table_access\\) $hex" \
+         "print My_P_Object.Ptr when no longer null"
+
+gdb_test "print my_p_object.ptr.all" \
+         "\\(13, 21, 34\\)"
+
diff --git a/gdb/testsuite/gdb.ada/unc_arr_ptr_in_var_rec/foo.adb b/gdb/testsuite/gdb.ada/unc_arr_ptr_in_var_rec/foo.adb
new file mode 100644
index 00000000000..0b5e4f2be82
--- /dev/null
+++ b/gdb/testsuite/gdb.ada/unc_arr_ptr_in_var_rec/foo.adb
@@ -0,0 +1,51 @@
+--  Copyright 2012 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 Pck; use Pck;
+
+procedure Foo is
+
+   type Table is array (Positive range <>) of Integer;
+   type Table_Access is access Table;
+
+   type Object (N : Integer) is record
+       Ptr  : Table_Access;
+       Data : Table (1 .. N);
+   end record;
+
+   My_Object : Object := (N => 3, Ptr => null, Data => (3, 5, 8));
+
+   --  Same as above, but with a pointer to an unconstrained packed array.
+
+   type Byte is range 0 .. 255;
+
+   type P_Table is array (Positive range <>) of Byte;
+   pragma Pack (P_Table);
+   type P_Table_Access is access P_Table;
+
+   type P_Object (N : Integer) is record
+       Ptr  : P_Table_Access;
+       Data : P_Table (1 .. N);
+   end record;
+
+   My_P_Object : P_Object := (N => 3, Ptr => null, Data => (3, 5, 8));
+
+begin
+   My_Object.Ptr := new Table'(13, 21, 34);    -- STOP1
+   My_P_Object.Ptr := new P_Table'(13, 21, 34);
+   Do_Nothing (My_Object'Address);             -- STOP2
+   Do_Nothing (My_P_Object'Address);
+end Foo;
+
diff --git a/gdb/testsuite/gdb.ada/unc_arr_ptr_in_var_rec/pck.adb b/gdb/testsuite/gdb.ada/unc_arr_ptr_in_var_rec/pck.adb
new file mode 100644
index 00000000000..1f7d45cf5e2
--- /dev/null
+++ b/gdb/testsuite/gdb.ada/unc_arr_ptr_in_var_rec/pck.adb
@@ -0,0 +1,21 @@
+--  Copyright 2012 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 Pck is
+   procedure Do_Nothing (A : System.Address) is
+   begin
+      null;
+   end Do_Nothing;
+end Pck;
diff --git a/gdb/testsuite/gdb.ada/unc_arr_ptr_in_var_rec/pck.ads b/gdb/testsuite/gdb.ada/unc_arr_ptr_in_var_rec/pck.ads
new file mode 100644
index 00000000000..c20c0d81d74
--- /dev/null
+++ b/gdb/testsuite/gdb.ada/unc_arr_ptr_in_var_rec/pck.ads
@@ -0,0 +1,19 @@
+--  Copyright 2012 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 System;
+package Pck is
+   procedure Do_Nothing (A : System.Address);
+end Pck;