gdb/testsuite/gdb.dwarf2/dw2-step-between-inline-func-blocks.exp

# Copyright 2024-2025 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/>.

# This test creates a function 'foo' that contains an inline function
# 'bar'.  Both 'foo' and 'bar' are split into two regions.  The layout
# in memory looks something like this:
#
#                    <part-a>  <gap>  <part-b>
#
# bar:         |------------|         |---|
# foo:   |------------------|         |--------|
#
# We see things like this in "real" code where the parts after the gap
# (part-b) are cold paths within the function that have been moved
# aside.
#
# However, in this test program we use 'goto' to jump directly from
# the first part of the function (part-a) to the second part (part-b).
#
# At the time we hit the goto we are inside 'bar'.  After the goto we
# expect to still be in bar.  At one point GDB would get this wrong
# and after the jump we would revert back to 'foo'.
#
# This bug will only trigger if both 'foo' and 'bar' are split, and
# both 'foo' and 'bar' must start at the same address for part-b.

load_lib dwarf.exp

require dwarf2_support

# The source program use 'goto *ADDR' which is a GCC extension.
require is_c_compiler_gcc

standard_testfile

# This compiles the source file and starts and stops GDB, so run it
# before calling prepare_for_testing otherwise GDB will have exited.
get_func_info foo

# Make some DWARF for the test.
set asm_file [standard_output_file "$::testfile-dw.S"]
Dwarf::assemble $asm_file {
    global srcfile

    # Create local varibles BAR_SRC_* containing the line number for
    # the four souce lines of 'foo' and 'bar'.  These will be
    # referenced in the generated DWARF.
    for { set i 1 } { $i <= 4 } { incr i } {
	set bar_src_$i [gdb_get_line_number "bar line $i"]
	set foo_src_$i [gdb_get_line_number "foo line $i"]
    }

    # More line numbers needed for the generated DWARF.
    set foo_decl_line [gdb_get_line_number "foo decl line"]
    set bar_decl_line [gdb_get_line_number "bar decl line"]

    # Labels used to link parts of the DWARF together.
    declare_labels lines_table bar_label ranges_label_bar ranges_label_foo

    cu { version 4 } {
	compile_unit {
	    {producer "gcc"}
	    {language @DW_LANG_C}
	    {name ${srcfile}}
	    {comp_dir /tmp}
	    {stmt_list $lines_table DW_FORM_sec_offset}
	    {low_pc 0 addr}
	} {
	    bar_label: subprogram {
		{external 1 flag}
		{name bar}
		{decl_file 1 data1}
		{decl_line $bar_decl_line data1}
		{decl_column 1 data1}
		{inline 3 data1}
	    }
	    subprogram {
		{name foo}
		{decl_file 1 data1}
		{decl_line $foo_decl_line data1}
		{decl_column 1 data1}
		{ranges ${ranges_label_foo} DW_FORM_sec_offset}
		{external 1 flag}
	    } {
		inlined_subroutine {
		    {abstract_origin %$bar_label}
		    {call_file 1 data1}
		    {call_line $foo_src_3 data1}
		    {ranges ${ranges_label_bar} DW_FORM_sec_offset}
		}
	    }
	}
    }

    lines {version 2} lines_table {
	include_dir "$::srcdir/$::subdir"
	file_name "$srcfile" 1
	program {
	    DW_LNE_set_address "foo_label"
	    line $foo_src_1
	    DW_LNS_copy
	    DW_LNE_set_address "foo_label_1"
	    line $foo_src_2
	    DW_LNS_copy
	    DW_LNE_set_address "foo_label_2"
	    line $foo_src_3
	    DW_LNS_copy
	    DW_LNE_set_address "foo_label_2"
	    line $bar_src_1
	    DW_LNS_copy
	    DW_LNE_set_address "foo_label_3"
	    line $bar_src_2
	    DW_LNS_copy

	    DW_LNE_set_address "foo_label_4"
	    DW_LNE_end_sequence

	    DW_LNE_set_address "foo_label_6"
	    line $bar_src_3
	    DW_LNS_copy
	    DW_LNE_set_address "foo_label_7"
	    line $bar_src_4
	    DW_LNS_copy

	    DW_LNS_negate_stmt
	    DW_LNE_set_address "foo_label_7"
	    line $foo_src_3
	    DW_LNS_copy

	    DW_LNS_negate_stmt
	    DW_LNE_set_address "foo_label_8"
	    line $foo_src_4
	    DW_LNS_copy

	    DW_LNE_set_address $::foo_end
	    DW_LNE_end_sequence
	}
    }

    ranges { } {
	ranges_label_bar: sequence {
	    range foo_label_2 foo_label_4
	    range foo_label_6 foo_label_8
	}
	ranges_label_foo: sequence {
	    range foo_label_1 foo_label_4
	    range foo_label_6 foo_label_9
	}
    }
}

if {[prepare_for_testing "failed to prepare" "${::testfile}" \
	 [list $srcfile $asm_file] {nodebug}]} {
    return -1
}

if ![runto_main] {
    return -1
}

gdb_breakpoint bar
gdb_continue_to_breakpoint "continue to bar line 1" \
    ".*bar line 1\[^\r\n\]+"

gdb_test "step" ".*bar line 2\[^\r\n\]+" \
    "step to bar line 2"

# This is the interesting one.  This step will take us over the goto
# and into the second range of both 'foo' and 'bar'.  As we started
# the step in 'bar' GDB should reselect 'bar' after the step.
#
# If this goes wrong the GDB will claim we are at foo_line_3, which is
# the DW_AT_call_line for 'bar'.
gdb_test "step" ".*bar line 3\[^\r\n\]+" \
    "step to bar line 3"

# These following steps should be straight forward, but lets just
# check we can step out of 'bar' and back to 'foo', there shouldn't be
# anything tricky going on here though.
gdb_test "step" ".*bar line 4\[^\r\n\]+" \
    "step to bar line 4"

gdb_test "step" ".*foo line 4\[^\r\n\]+" \
    "step out of bar to foo line 4"