From: Tom Tromey <tromey@adacore.com>
To: gdb-patches@sourceware.org
Cc: Tom Tromey <tromey@adacore.com>
Subject: [PATCH] Fix bit offset regression
Date: Fri, 9 Oct 2020 07:41:30 -0600 [thread overview]
Message-ID: <20201009134130.3785956-1-tromey@adacore.com> (raw)
The type-safe attribute patch introduced a regression that can occur
when the DW_AT_bit_offset value is negative. This can happen with
some Ada programs.
This patch fixes the problem. It also fixes a minor oddity in the
existing scalar storage test -- this test was intended to assign a
smaller number of bits to the field.
gdb/ChangeLog
2020-10-09 Tom Tromey <tromey@adacore.com>
* dwarf2/read.c (dwarf2_add_field): Handle signed offsets.
gdb/testsuite/ChangeLog
2020-10-09 Tom Tromey <tromey@adacore.com>
* gdb.ada/scalar_storage/storage.adb (Another_Range): New type.
(Rec): Add field. Fix range.
* gdb.ada/scalar_storage.exp: Update.
---
gdb/ChangeLog | 4 ++++
gdb/dwarf2/read.c | 10 +++++-----
gdb/testsuite/ChangeLog | 6 ++++++
gdb/testsuite/gdb.ada/scalar_storage.exp | 4 ++--
gdb/testsuite/gdb.ada/scalar_storage/storage.adb | 9 ++++++---
5 files changed, 23 insertions(+), 10 deletions(-)
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index eedfea112d9..2ec3789135d 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -15050,7 +15050,7 @@ dwarf2_add_field (struct field_info *fip, struct die_info *die,
/* Get bit offset of field. */
handle_data_member_location (die, cu, fp);
attr = dwarf2_attr (die, DW_AT_bit_offset, cu);
- if (attr != nullptr && attr->form_is_unsigned ())
+ if (attr != nullptr && attr->form_is_constant ())
{
if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
{
@@ -15060,7 +15060,7 @@ dwarf2_add_field (struct field_info *fip, struct die_info *die,
have to do anything special since we don't need to
know the size of the anonymous object. */
SET_FIELD_BITPOS (*fp, (FIELD_BITPOS (*fp)
- + attr->as_unsigned ()));
+ + attr->constant_value (0)));
}
else
{
@@ -15071,15 +15071,15 @@ dwarf2_add_field (struct field_info *fip, struct die_info *die,
the field itself. The result is the bit offset of
the LSB of the field. */
int anonymous_size;
- int bit_offset = attr->as_unsigned ();
+ int bit_offset = attr->constant_value (0);
attr = dwarf2_attr (die, DW_AT_byte_size, cu);
- if (attr != nullptr && attr->form_is_unsigned ())
+ if (attr != nullptr && attr->form_is_constant ())
{
/* The size of the anonymous object containing
the bit field is explicit, so use the
indicated size (in bytes). */
- anonymous_size = attr->as_unsigned ();
+ anonymous_size = attr->constant_value (0);
}
else
{
diff --git a/gdb/testsuite/gdb.ada/scalar_storage.exp b/gdb/testsuite/gdb.ada/scalar_storage.exp
index b5e634c615b..952d7fd136e 100644
--- a/gdb/testsuite/gdb.ada/scalar_storage.exp
+++ b/gdb/testsuite/gdb.ada/scalar_storage.exp
@@ -34,5 +34,5 @@ if ![runto "storage.adb:$bp_location" ] then {
return
}
-gdb_test "print V_LE" "= \\(value => 126\\)"
-gdb_test "print V_BE" "= \\(value => 126\\)"
+gdb_test "print V_LE" "= \\(value => 126, another_value => 12\\)"
+gdb_test "print V_BE" "= \\(value => 126, another_value => 12\\)"
diff --git a/gdb/testsuite/gdb.ada/scalar_storage/storage.adb b/gdb/testsuite/gdb.ada/scalar_storage/storage.adb
index 608425d9dd1..741718e4e51 100644
--- a/gdb/testsuite/gdb.ada/scalar_storage/storage.adb
+++ b/gdb/testsuite/gdb.ada/scalar_storage/storage.adb
@@ -18,13 +18,16 @@ with System.Storage_Elements; use System.Storage_Elements;
procedure Storage is
subtype Some_Range is Natural range 0..127;
+ subtype Another_Range is Natural range 0..15;
type Rec is record
Value : Some_Range;
+ Another_Value : Another_Range;
end record;
for Rec use record
- Value at 0 range 0..127;
+ Value at 0 range 0..6;
+ Another_Value at 0 range 7..10;
end record;
type Rec_LE is new Rec;
@@ -39,8 +42,8 @@ procedure Storage is
V_BE : Rec_BE;
begin
- V_LE.Value := 126;
- V_BE.Value := 126;
+ V_LE := (126, 12);
+ V_BE := (126, 12);
Do_Nothing (V_LE'Address); -- START
Do_Nothing (V_BE'Address);
--
2.26.2
next reply other threads:[~2020-10-09 13:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-09 13:41 Tom Tromey [this message]
2020-10-09 14:27 ` Andrew Burgess
2020-10-09 17:18 ` Tom Tromey
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