diff mbox series

[05/13] Use correct sign for DW_AT_GNU_bias

Message ID	20250320-attribute-madness-v1-5-79d42789f881@adacore.com
State	New
Headers	DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 6CB6F3858039 From: Tom Tromey <tromey@adacore.com> Date: Thu, 20 Mar 2025 13:27:01 -0600 Subject: [PATCH 05/13] Use correct sign for DW_AT_GNU_bias MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20250320-attribute-madness-v1-5-79d42789f881@adacore.com> References: <20250320-attribute-madness-v1-0-79d42789f881@adacore.com> In-Reply-To: <20250320-attribute-madness-v1-0-79d42789f881@adacore.com> To: gdb-patches@sourceware.org Cc: Tom Tromey <tromey@adacore.com> Precedence: list Errors-To: gdb-patches-bounces~patchwork=sourceware.org@sourceware.org
Series	More work on DW_FORM_* and sign handling \| [00/13] More work on DW_FORM_* and sign handling [01/13] Use attribute::unsigned_constant for sizes [02/13] Introduce attribute::signed_constant [03/13] Use attribute::signed_constant for fixed-point scale [04/13] Use attribute::unsigned_constant for DW_AT_bit_stride [05/13] Use correct sign for DW_AT_GNU_bias [06/13] Use attribute::unsigned_constant for DW_AT_data_bit_offset [07/13] Use attribute::unsigned_constant for DW_AT_data_member_location [08/13] Use correct sign in get_mpz [09/13] Use correct sign for variant part discriminants [10/13] Use attribute::signed_constant in attribute::as_boolean [11/13] Remove dead code from dwarf2_const_value_data [12/13] Use bool in update_enumeration_type_from_children [13/13] Use correct sign extension for enumeration types

Checks

Context	Check	Description
linaro-tcwg-bot/tcwg_gdb_build--master-aarch64	fail	Patch failed to apply
linaro-tcwg-bot/tcwg_gdb_build--master-arm	fail	Patch failed to apply

Commit Message

Tom Tromey March 20, 2025, 7:27 p.m. UTC

  DW_AT_GNU_bias may be signed or unsigned, depending on the underlying
type.  This patch changes the DWARF reader to examine the type before
decoding the attribute.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32680
---
 gdb/dwarf2/read.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff mbox series

Patch

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index b48e5db82bca388fb122de05695ea1f3c9abdb1a..bd3951a263c43597b1b77afa901e3c17947a71a4 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -14230,8 +14230,13 @@  read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
 
   LONGEST bias = 0;
   struct attribute *bias_attr = dwarf2_attr (die, DW_AT_GNU_bias, cu);
-  if (bias_attr != nullptr && bias_attr->form_is_constant ())
-    bias = bias_attr->constant_value (0);
+  if (bias_attr != nullptr)
+    {
+      if (base_type->is_unsigned ())
+	bias = (LONGEST) bias_attr->unsigned_constant ().value_or (0);
+      else
+	bias = bias_attr->signed_constant ().value_or (0);
+    }
 
   /* Normally, the DWARF producers are expected to use a signed
      constant form (Eg. DW_FORM_sdata) to express negative bounds.