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# Copyright 2022-2024 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/>.
# Check that GDB can honor the epilogue_begin flag the compiler can place
# in the line-table data.
# We test 2 things: 1. that a software watchpoint triggered in an epilogue
# is correctly ignored
# 2. that GDB can mark the same line as both prologue and epilogue
load_lib dwarf.exp
# This test can only be run on targets which support DWARF-2 and use gas.
require dwarf2_support
# restricted to x86 to make it simpler to follow a variable
require is_x86_64_m64_target
set trivial_line [gdb_get_line_number "trivial function"]
set main_prologue [gdb_get_line_number "main prologue"]
set main_epilogue [gdb_get_line_number "main end"]
set watch_start_line [gdb_get_line_number "watch start"]
set asm_file [standard_output_file $srcfile2]
# The producer will be set to clang because at the time of writing
# we only care about epilogues if the producer is clang. When the
# producer is GCC, variables use CFA locations, so watchpoints can
# continue working even on epilogues.
Dwarf::assemble $asm_file {
global srcdir subdir srcfile srcfile2
global trivial_line main_prologue main_epilogue watch_start_line
declare_labels lines_label
get_func_info main
get_func_info trivial
get_func_info watch
if { $::version == 1 } {
set switch_file {}
} elseif { $::version == 2 } {
set switch_file { set f $f2 }
} else {
error "Unhandled version: $::version"
}
cu {} {
compile_unit {
{language @DW_LANG_C}
{name dw2-prologue-end.c}
{stmt_list ${lines_label} DW_FORM_sec_offset}
{producer "clang version 17.0.1"}
} {
declare_labels char_label
char_label: base_type {
{name char}
{encoding @DW_ATE_signed}
{byte_size 1 DW_FORM_sdata}
}
subprogram {
{external 1 flag}
{name trivial}
{low_pc $trivial_start addr}
{high_pc "$trivial_start + $trivial_len" addr}
}
subprogram {
{external 1 flag}
{name watch}
{low_pc $watch_start addr}
{high_pc "$watch_start + $watch_len" addr}
} {
DW_TAG_variable {
{name local}
{type :$char_label}
{DW_AT_location {DW_OP_reg0} SPECIAL_expr}
}
}
subprogram {
{external 1 flag}
{name main}
{low_pc $main_start addr}
{high_pc "$main_start + $main_len" addr}
}
}
}
lines {version 5} lines_label {
set diridx [include_dir "${srcdir}/${subdir}"]
set f1 [file_name "$srcfile" $diridx]
set f2 [file_name "$srcfile.inc" $diridx]
set f $f1
program {
DW_LNS_set_file $f
DW_LNE_set_address $trivial_start
line $trivial_line
DW_LNS_set_prologue_end
DW_LNS_set_epilogue_begin
DW_LNS_copy
DW_LNE_set_address $trivial_end
DW_LNE_end_sequence
DW_LNS_set_file $f
DW_LNE_set_address $watch_start
line $watch_start_line
DW_LNS_copy
DW_LNE_set_address watch_start
line [gdb_get_line_number "watch assign"]
DW_LNS_set_prologue_end
DW_LNS_copy
eval $switch_file
DW_LNS_set_file $f
DW_LNE_set_address watch_reassign
line [gdb_get_line_number "watch reassign"]
DW_LNS_set_epilogue_begin
DW_LNS_copy
DW_LNE_set_address watch_end
line [gdb_get_line_number "watch end"]
DW_LNS_copy
DW_LNE_set_address $watch_end
DW_LNE_end_sequence
DW_LNS_set_file $f
DW_LNE_set_address $main_start
line $main_prologue
DW_LNS_set_prologue_end
DW_LNS_copy
DW_LNE_set_address main_fun_call
line [gdb_get_line_number "main function call"]
DW_LNS_copy
DW_LNE_set_address main_epilogue
line $main_epilogue
DW_LNS_set_epilogue_begin
DW_LNS_copy
DW_LNE_set_address $main_end
DW_LNE_end_sequence
}
}
}
if { [prepare_for_testing "failed to prepare" ${testfile} \
[list $srcfile $asm_file] {nodebug}] } {
return -1
}
if ![runto_main] {
return -1
}
# Moving to the scope with a local variable.
gdb_breakpoint $srcfile:$watch_start_line
gdb_continue_to_breakpoint "continuing to function" ".*"
gdb_test "next" "local = 2.*" "stepping to epilogue"
# Forcing software watchpoints because hardware ones don't care if we
# are in the epilogue or not.
gdb_test_no_output "set can-use-hw-watchpoints 0"
# Test that the software watchpoint will not trigger in this case
gdb_test "watch local" "\[W|w\]atchpoint .: local" "set watchpoint"
gdb_test "continue" ".*\[W|w\]atchpoint . deleted.*" \
"confirm watchpoint doesn't trigger"
# First we test that the trivial function has a line with both a prologue
# and an epilogue. Do this by finding a line that has 3 Y columns
set sep "\[ \t\]"
set hex_number "0x\[0-9a-f\]+"
gdb_test_multiple "maint info line-table" "test epilogue in linetable" -lbl {
-re "\[0-9\]$sep+$trivial_line$sep+$hex_number$sep+$hex_number$sep+Y$sep+Y$sep+Y" {
pass $gdb_test_name
}
}
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