[PATCH 2/2] Fix bug in assignment to nested packed structure

[PATCH 2/2] Fix bug in assignment to nested packed structure

[Tom Tromey]

A user at AdaCore found a case where assignment to a nested packed
structure would fail.  The bug is that ada_value_primitive_field
doesn't account for the situation where a field is not packed relative
to its containing structure, but where the structure itself is packed
in its parent.

2019-04-29  Tom Tromey  <tromey@adacore.com>

	* ada-lang.c (ada_value_primitive_field): Treat more fields as
	bitfields.

gdb/testsuite/ChangeLog
2019-04-29  Tom Tromey  <tromey@adacore.com>

	* gdb.ada/packed_array_assign/aggregates.ads (Nested_Packed): New
	record.
	(NPR): New variable.
	* gdb.ada/packed_array_assign.exp: Add nested packed assignment
	test.
---
 gdb/ChangeLog                                            | 5 +++++
 gdb/ada-lang.c                                           | 7 ++++---
 gdb/testsuite/ChangeLog                                  | 8 ++++++++
 gdb/testsuite/gdb.ada/packed_array_assign.exp            | 3 +++
 gdb/testsuite/gdb.ada/packed_array_assign/aggregates.ads | 7 +++++++
 5 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 422bfdb3b8d..3744ae27f56 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -7158,9 +7158,10 @@ ada_value_primitive_field (struct value *arg1, int offset, int fieldno,
   arg_type = ada_check_typedef (arg_type);
   type = TYPE_FIELD_TYPE (arg_type, fieldno);
 
-  /* Handle packed fields.  */
-
-  if (TYPE_FIELD_BITSIZE (arg_type, fieldno) != 0)
+  /* Handle packed fields.  It might be that the field is not packed
+     relative to its containing structure, but the structure itself is
+     packed; in this case we must take the bit-field path.  */
+  if (TYPE_FIELD_BITSIZE (arg_type, fieldno) != 0 || value_bitpos (arg1) != 0)
     {
       int bit_pos = TYPE_FIELD_BITPOS (arg_type, fieldno);
       int bit_size = TYPE_FIELD_BITSIZE (arg_type, fieldno);
diff --git a/gdb/testsuite/gdb.ada/packed_array_assign.exp b/gdb/testsuite/gdb.ada/packed_array_assign.exp
index 8ed2d63ecf3..407ea9cecbb 100644
--- a/gdb/testsuite/gdb.ada/packed_array_assign.exp
+++ b/gdb/testsuite/gdb.ada/packed_array_assign.exp
@@ -33,3 +33,6 @@ gdb_test "print pra(1) := pr" \
     " = \\(packed_array_assign_w => 104, packed_array_assign_x => 2, packed_array_assign_y => 3\\)"
 gdb_test "print pra(1)" \
     " = \\(packed_array_assign_w => 104, packed_array_assign_x => 2, packed_array_assign_y => 3\\)"
+
+gdb_test "print npr := (q000 => 3, r000 => (packed_array_assign_x => 6, packed_array_assign_y => 1, packed_array_assign_w => 117))" \
+    " = \\(q000 => 3, r000 => \\(packed_array_assign_w => 117, packed_array_assign_x => 6, packed_array_assign_y => 1\\)\\)"
diff --git a/gdb/testsuite/gdb.ada/packed_array_assign/aggregates.ads b/gdb/testsuite/gdb.ada/packed_array_assign/aggregates.ads
index f0d052510e4..d1b0552bbd1 100644
--- a/gdb/testsuite/gdb.ada/packed_array_assign/aggregates.ads
+++ b/gdb/testsuite/gdb.ada/packed_array_assign/aggregates.ads
@@ -25,6 +25,12 @@ package Aggregates is
    type Packed_RecArr is array (Integer range <>) of Packed_Rec;
    pragma Pack (Packed_RecArr);
 
+   type Nested_Packed is record
+      Q000 : Int;
+      R000 : Packed_Rec;
+   end record;
+   pragma Pack (Nested_Packed);
+
    procedure Run_Test;
 
 private
@@ -32,4 +38,5 @@ private
                        Packed_Array_Assign_W => 104,
                        Packed_Array_Assign_X  => 2);
    PRA : Packed_RecArr (1 .. 3);
+   NPR : Nested_Packed := (q000 => 3, r000 => (packed_array_assign_x => 6, packed_array_assign_y => 1, packed_array_assign_w => 117));
 end Aggregates;
-- 
2.20.1

[PATCH 1/2] Fix big-endian aggregate assignment in Ada

[Tom Tromey]

A bug internal to AdaCore notes that assigning a non-scalar value to
an element of a packed array will sometimes fail.

The bug turns out to be that ada_value_assign incorrectly computes the
starting point for the assignment.  This patch fixes the problem.

gdb/ChangeLog
2019-04-29  Tom Tromey  <tromey@adacore.com>

	* ada-lang.c (ada_value_assign): Correctly compute starting offset
	for big-endian copies.

gdb/testsuite/ChangeLog
2019-04-29  Tom Tromey  <tromey@adacore.com>

	* gdb.ada/packed_array_assign.exp: Add packed assignment
	regression test.
---
 gdb/ChangeLog                                 |  5 +++++
 gdb/ada-lang.c                                | 14 ++++++++------
 gdb/testsuite/ChangeLog                       |  5 +++++
 gdb/testsuite/gdb.ada/packed_array_assign.exp |  5 +++++
 4 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 250ce438b1a..422bfdb3b8d 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -2709,12 +2709,14 @@ ada_value_assign (struct value *toval, struct value *fromval)
       from_size = value_bitsize (fromval);
       if (from_size == 0)
 	from_size = TYPE_LENGTH (value_type (fromval)) * TARGET_CHAR_BIT;
-      if (gdbarch_bits_big_endian (get_type_arch (type)))
-        copy_bitwise (buffer, value_bitpos (toval),
-		      value_contents (fromval), from_size - bits, bits, 1);
-      else
-        copy_bitwise (buffer, value_bitpos (toval),
-		      value_contents (fromval), 0, bits, 0);
+
+      const int is_big_endian = gdbarch_bits_big_endian (get_type_arch (type));
+      ULONGEST from_offset = 0;
+      if (is_big_endian && is_scalar_type (value_type (fromval)))
+	from_offset = from_size - bits;
+      copy_bitwise (buffer, value_bitpos (toval),
+		    value_contents (fromval), from_offset,
+		    bits, is_big_endian);
       write_memory_with_notification (to_addr, buffer, len);
 
       val = value_copy (toval);
diff --git a/gdb/testsuite/gdb.ada/packed_array_assign.exp b/gdb/testsuite/gdb.ada/packed_array_assign.exp
index 93910ac6cb4..8ed2d63ecf3 100644
--- a/gdb/testsuite/gdb.ada/packed_array_assign.exp
+++ b/gdb/testsuite/gdb.ada/packed_array_assign.exp
@@ -28,3 +28,8 @@ runto "aggregates.run_test"
 gdb_test \
     "print pra := ((packed_array_assign_x => 2, packed_array_assign_y => 0, packed_array_assign_w => 17), pr, (packed_array_assign_x => 7, packed_array_assign_y => 1, packed_array_assign_w => 23))" \
     " = \\(\\(packed_array_assign_w => 17, packed_array_assign_x => 2, packed_array_assign_y => 0\\), \\(packed_array_assign_w => 104, packed_array_assign_x => 2, packed_array_assign_y => 3\\), \\(packed_array_assign_w => 23, packed_array_assign_x => 7, packed_array_assign_y => 1\\)\\)"
+
+gdb_test "print pra(1) := pr" \
+    " = \\(packed_array_assign_w => 104, packed_array_assign_x => 2, packed_array_assign_y => 3\\)"
+gdb_test "print pra(1)" \
+    " = \\(packed_array_assign_w => 104, packed_array_assign_x => 2, packed_array_assign_y => 3\\)"
-- 
2.20.1

[PATCH 0/2] Fix two Ada assignment bugs

[Tom Tromey]

This series fixes two bugs in the Ada code related to aggregate
assignment.  They were reported internally by users at AdaCore.

I think each patch is reasonably self-explanatory.

Tested by the buildbot.

Tom

Re: [PATCH 0/2] Fix two Ada assignment bugs

[Joel Brobecker]

Hi Tom,

> This series fixes two bugs in the Ada code related to aggregate
> assignment.  They were reported internally by users at AdaCore.
> 
> I think each patch is reasonably self-explanatory.

Thanks for those. I reviewed both patches, and they look good to me.

-- 
Joel