File gdb-symtab-workaround-pr-gas-31115.patch of Package gdb-debuginfod
From d25e3f4ed05c3a6c207263d7e532f829860b83f0 Mon Sep 17 00:00:00 2001
From: Tom de Vries <tdevries@suse.de>
Date: Wed, 20 Mar 2024 09:57:49 +0100
Subject: [PATCH 1/7] [gdb/symtab] Workaround PR gas/31115
On arm-linux, with gas 2.40, I run into:
...
(gdb) x /i main+8^M
0x4e1 <main+7>: vrhadd.u16 d14, d14, d31^M
(gdb) FAIL: gdb.arch/pr25124.exp: disassemble thumb instruction (1st try)
...
This is a regression due to PR gas/31115, which makes gas produce a low_pc
with the thumb bit set (0x4d8 & 0x1):
...
<1><24>: Abbrev Number: 2 (DW_TAG_subprogram)
<25> DW_AT_name : main
<29> DW_AT_external : 1
<29> DW_AT_type : <0x2f>
<2a> DW_AT_low_pc : 0x4d9
<2e> DW_AT_high_pc : 12
...
The regression was introduced in 2.39, and is also present in 2.40 and 2.41,
and hasn't been fixed yet.
Work around this in read_func_scope, by using gdbarch_addr_bits_remove on
low_pc and high_pc.
Tested on arm-linux and x86_64-linux.
PR tdep/31453
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31453
---
gdb/dwarf2/cu.c | 1 +
gdb/dwarf2/cu.h | 1 +
gdb/dwarf2/read.c | 22 ++++++++++++++++++++++
3 files changed, 24 insertions(+)
diff --git a/gdb/dwarf2/cu.c b/gdb/dwarf2/cu.c
index f9b05dfc709..7f89500effd 100644
--- a/gdb/dwarf2/cu.c
+++ b/gdb/dwarf2/cu.c
@@ -42,6 +42,7 @@ dwarf2_cu::dwarf2_cu (dwarf2_per_cu_data *per_cu,
producer_is_clang (false),
producer_is_gas_lt_2_38 (false),
producer_is_gas_2_39 (false),
+ producer_is_gas_ge_2_40 (false),
processing_has_namespace_info (false),
load_all_dies (false)
{
diff --git a/gdb/dwarf2/cu.h b/gdb/dwarf2/cu.h
index ef8db480e3f..1b02f89ed2f 100644
--- a/gdb/dwarf2/cu.h
+++ b/gdb/dwarf2/cu.h
@@ -267,6 +267,7 @@ struct dwarf2_cu
bool producer_is_clang : 1;
bool producer_is_gas_lt_2_38 : 1;
bool producer_is_gas_2_39 : 1;
+ bool producer_is_gas_ge_2_40 : 1;
/* When true, the file that we're processing is known to have
debugging info for C++ namespaces. GCC 3.3.x did not produce
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index a4f982962ae..8f2d7a34aef 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -148,6 +148,7 @@ static int dwarf2_loclist_block_index;
static int ada_block_index;
static bool producer_is_gas_lt_2_38 (struct dwarf2_cu *cu);
+static bool producer_is_gas_ge_2_39 (struct dwarf2_cu *cu);
/* Size of .debug_loclists section header for 32-bit DWARF format. */
#define LOCLIST_HEADER_SIZE32 12
@@ -10223,6 +10224,15 @@ read_func_scope (struct die_info *die, struct dwarf2_cu *cu)
lowpc = per_objfile->relocate (unrel_low);
highpc = per_objfile->relocate (unrel_high);
+ if (gdbarch_bfd_arch_info (gdbarch)->arch == bfd_arch_arm
+ && producer_is_gas_ge_2_39 (cu))
+ {
+ /* Gas version 2.39 produces DWARF for a Thumb subprogram with a low_pc
+ attribute with the thumb bit set (PR gas/31115). Work around this. */
+ lowpc = gdbarch_addr_bits_remove (gdbarch, lowpc);
+ highpc = gdbarch_addr_bits_remove (gdbarch, highpc);
+ }
+
/* If we have any template arguments, then we must allocate a
different sort of symbol. */
for (child_die = die->child; child_die; child_die = child_die->sibling)
@@ -11507,6 +11517,7 @@ check_producer (struct dwarf2_cu *cu)
{
cu->producer_is_gas_lt_2_38 = major < 2 || (major == 2 && minor < 38);
cu->producer_is_gas_2_39 = major == 2 && minor == 39;
+ cu->producer_is_gas_ge_2_40 = major > 2 || (major == 2 && minor >= 40);
}
else
{
@@ -11561,6 +11572,17 @@ producer_is_gas_2_39 (struct dwarf2_cu *cu)
return cu->producer_is_gas_2_39;
}
+/* Return true if CU is produced by GAS 2.39 or later. */
+
+static bool
+producer_is_gas_ge_2_39 (struct dwarf2_cu *cu)
+{
+ if (!cu->checked_producer)
+ check_producer (cu);
+
+ return cu->producer_is_gas_2_39 || cu->producer_is_gas_ge_2_40;
+}
+
/* Return the accessibility of DIE, as given by DW_AT_accessibility.
If that attribute is not available, return the appropriate
default. */
base-commit: c79ecacd3f75cfb0ec1a3afc49ca3f30b1759009
--
2.35.3
