# Copyright 2018-2019 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/>.
load_lib dwarf.exp

# Test DW_AT_ranges in the context of a subprogram scope.

# This test can only be run on targets which support DWARF-2 and use gas.
if {![dwarf2_support]} {
    unsupported "dwarf2 support required for this test"
    return 0
}

if [get_compiler_info] {
    return -1
}
if !$gcc_compiled {
    unsupported "gcc required for this test"
    return 0
}

standard_testfile dw2-ranges-func.c dw2-ranges-func-dw.S

# We need to know the size of integer and address types in order to
# write some of the debugging info we'd like to generate.
#
# For that, we ask GDB by debugging our test program.  Any program
# would do, but since we already have it specifically for this
# testcase, might as well use that.

if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile}] } {
    return -1
}

set asm_file [standard_output_file $srcfile2]
Dwarf::assemble $asm_file {
    global srcdir subdir srcfile srcfile2
    declare_labels integer_label volatile_label func_ranges_label cu_ranges_label L
    set int_size [get_sizeof "int" 4]

    # Find start address and length for our functions.
    lassign [function_range main [list ${srcdir}/${subdir}/$srcfile]] \
	main_start main_len
    set main_end "$main_start + $main_len"
    lassign [function_range foo [list ${srcdir}/${subdir}/$srcfile]] \
	foo_start foo_len
    set foo_end "$foo_start + $foo_len"
    lassign [function_range foo_low [list ${srcdir}/${subdir}/$srcfile]] \
	foo_low_start foo_low_len
    set foo_low_end "$foo_low_start + $foo_low_len"
    lassign [function_range bar [list ${srcdir}/${subdir}/$srcfile]] \
	bar_start bar_len
    set bar_end "$bar_start + $bar_len"
    lassign [function_range baz [list ${srcdir}/${subdir}/$srcfile]] \
	baz_start baz_len
    set baz_end "$baz_start + $baz_len"

    set e_var [gdb_target_symbol e]

    cu {} {
	compile_unit {
	    {language @DW_LANG_C}
	    {name dw-ranges-func.c}
	    {stmt_list $L DW_FORM_sec_offset}
	    {low_pc 0 addr}
	    {ranges ${cu_ranges_label} DW_FORM_sec_offset}
	} {
	    integer_label: DW_TAG_base_type {
		{DW_AT_byte_size $int_size DW_FORM_sdata}
		{DW_AT_encoding  @DW_ATE_signed}
		{DW_AT_name      integer}
	    }
	    volatile_label: DW_TAG_volatile_type {
		{type :$integer_label}
	    }
	    DW_TAG_variable {
		{name e}
		{external 1 flag}
		{type :$volatile_label}
		{location {addr $e_var} SPECIAL_expr}
	    }
	    subprogram {
		{external 1 flag}
		{name main}
		{DW_AT_type :$integer_label}
		{low_pc $main_start addr}
		{high_pc $main_len DW_FORM_data4}
	    }
	    subprogram {
		{external 1 flag}
		{name foo}
		{ranges ${func_ranges_label} DW_FORM_sec_offset}
	    }
	    subprogram {
		{external 1 flag}
		{name bar}
		{low_pc $bar_start addr}
		{high_pc $bar_len DW_FORM_data4}
	    }
	    subprogram {
		{external 1 flag}
		{name baz}
		{low_pc $baz_start addr}
		{high_pc $baz_len DW_FORM_data4}
	    }
	}
    }

    lines {version 2} L {
	include_dir "${srcdir}/${subdir}"
	file_name "$srcfile" 1

	# Generate a line table program.  An attempt was made to make it
	# reasonably accurate as it made debugging the test case easier.
	program {
	    {DW_LNE_set_address $main_start}
	    {DW_LNS_advance_line [expr [gdb_get_line_number "main prologue"] - 1]}
	    {DW_LNS_copy}
	    {DW_LNE_set_address main_label}
	    {DW_LNS_advance_line [expr [gdb_get_line_number "main foo call"] - [gdb_get_line_number "main prologue"]]}
	    {DW_LNS_copy}
	    {DW_LNE_set_address main_label2}
	    {DW_LNS_advance_line [expr [gdb_get_line_number "main return"] - [gdb_get_line_number "main foo call"]]}
	    {DW_LNS_copy}
	    {DW_LNE_set_address $main_end}
	    {DW_LNS_advance_line [expr [gdb_get_line_number "main end"] - [gdb_get_line_number "main return"] + 1]}
	    {DW_LNS_copy}
	    {DW_LNE_end_sequence}

	    {DW_LNE_set_address $foo_start}
	    {DW_LNS_advance_line [expr [gdb_get_line_number "foo prologue"] - 1] }
	    {DW_LNS_copy}
	    {DW_LNE_set_address foo_label}
	    {DW_LNS_advance_line [expr [gdb_get_line_number "foo bar call"] - [gdb_get_line_number "foo prologue"]]}
	    {DW_LNS_copy}
	    {DW_LNE_set_address foo_label2}
	    {DW_LNS_advance_line [expr [gdb_get_line_number "foo foo_low call"] - [gdb_get_line_number "foo bar call"]]}
	    {DW_LNS_copy}
	    {DW_LNE_set_address foo_label3}
	    {DW_LNS_advance_line [expr [gdb_get_line_number "foo end"] - [gdb_get_line_number "foo foo_low call"]]}
	    {DW_LNS_copy}
	    {DW_LNE_set_address $foo_end}
	    {DW_LNS_advance_line 1}
	    {DW_LNS_copy}
	    {DW_LNE_end_sequence}

	    {DW_LNE_set_address $bar_start}
	    {DW_LNS_advance_line [expr [gdb_get_line_number "bar end"] - 1]}
	    {DW_LNS_copy}
	    {DW_LNS_advance_pc $bar_len}
	    {DW_LNS_advance_line 1}
	    {DW_LNS_copy}
	    {DW_LNE_end_sequence}

	    {DW_LNE_set_address $baz_start}
	    {DW_LNS_advance_line [expr [gdb_get_line_number "baz end"] - 1]}
	    {DW_LNS_copy}
	    {DW_LNS_advance_pc $baz_len}
	    {DW_LNS_advance_line 1}
	    {DW_LNS_copy}
	    {DW_LNE_end_sequence}

	    {DW_LNE_set_address $foo_low_start}
	    {DW_LNS_advance_line [expr [gdb_get_line_number "foo_low prologue"] - 1]}
	    {DW_LNS_copy}
	    {DW_LNE_set_address foo_low_label}
	    {DW_LNS_advance_line [expr [gdb_get_line_number "foo_low baz call"] - [gdb_get_line_number "foo_low prologue"]]}
	    {DW_LNS_copy}
	    {DW_LNE_set_address foo_low_label2}
	    {DW_LNS_advance_line [expr [gdb_get_line_number "foo_low end"] - [gdb_get_line_number "foo_low baz call"]]}
	    {DW_LNS_copy}
	    {DW_LNE_set_address $foo_low_end}
	    {DW_LNS_advance_line 1}
	    {DW_LNS_copy}
	    {DW_LNE_end_sequence}
	}
    }

    # Generate ranges data.
    ranges {is_64 [is_64_target]} {
	func_ranges_label: sequence {
	    {range {$foo_start } $foo_end}
	    {range {$foo_low_start} $foo_low_end}
	}
	cu_ranges_label: sequence {
	    {range {$foo_start } $foo_end}
	    {range {$foo_low_start} $foo_low_end}
	    {range {$main_start} $main_end}
	    {range {$bar_start} $bar_end}
	    {range {$baz_start} $baz_end}
	}
    }
}

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

if ![runto_main] {
    return -1
}

set main_prologue_line_num [gdb_get_line_number "main prologue"]
# Do a sanity check to make sure that line number info is available.
gdb_test "info line main" \
    "Line ${main_prologue_line_num} of .* starts at address .* and ends at .*"

with_test_prefix "step-test-1" {
    set bp_foo_bar [gdb_get_line_number "foo bar call"]

    gdb_test "break $bp_foo_bar" \
	"Breakpoint.*at.* file .*$srcfile, line $bp_foo_bar\\." \
	"break at call to bar"

    gdb_test "continue" \
	"Continuing\\..*Breakpoint \[0-9\]+, foo \\(\\).*$bp_foo_bar\\s+bar\\s\\(\\);.*foo bar call.*" \
	"continue to call of bar"

    gdb_test "step" \
	"bar \\(\\).*bar end.*" \
	"step into bar"

    gdb_test "step" \
	"foo \\(\\).*foo foo_low call.*" \
	"step out of bar, back into foo"
}

with_test_prefix "step-test-2" {
    clean_restart ${testfile}
    if ![runto_main] {
	return -1
    }

    # Note that the RE used for the following test will fail when the
    # breakpoint has been set on multiple locations. E.g. "(2 locations)". 
    # This is intentional since that behavior is one of the bugs that
    # this test case tests for.
    gdb_test "break foo" \
	"Breakpoint.*at.* file .*$srcfile, line \\d+\\." \
	"break foo"

    # Continue to foo.  Allow execution to stop either on the prologue
    # or on the call to bar since either behavior is acceptable though
    # the latter is preferred.
    set test "continue to foo"
    gdb_test_multiple "continue" $test {
	-re "Breakpoint \\d+, foo \\(\\).*foo prologue.*${gdb_prompt}" {
	    pass $test
	    gdb_test "step" \
		     "foo bar call .*" \
		     "step to call of bar after landing on prologue"
	}
	-re "Breakpoint \\d+, foo \\(\\).*foo bar call.*${gdb_prompt}" {
	    pass $test
	}
    }

    gdb_test "step" \
	"bar \\(\\).*bar end.*" \
	"step into bar"

    gdb_test "step" \
	"foo \\(\\).*foo foo_low call.*" \
	"step out of bar, back into foo"
}

clean_restart ${testfile}
if ![runto_main] {
    return -1
}

# Disassembly of foo should have multiple address ranges.
gdb_test_sequence "disassemble foo" "" [list \
    "Dump of assembler code for function foo:" \
    "Address range $hex to $hex:" \
    "   $hex <\\+0>:" \
    "Address range $hex to $hex:" \
    "   $hex <(.+?)>:" \
    "End of assembler dump\\." \
]

set foo_low_addr -1
set test "x/i foo_low"
gdb_test_multiple $test $test {
    -re "   ($hex) <foo.*?>.*${gdb_prompt}" {
	set foo_low_addr $expect_out(1,string)
	pass $test
    }
}

set foo_addr -1
set test "x/i foo"
gdb_test_multiple $test $test {
    -re "   ($hex) <foo.*?>.*${gdb_prompt}" {
	set foo_addr $expect_out(1,string)
	pass $test
    }
}

gdb_assert {$foo_low_addr != $foo_addr} "foo and foo_low are at different addresses"

# This more permissive RE for "break foo" will allow a breakpoint on
# multiple locations to PASS.  */
gdb_test "break foo" \
    "Breakpoint.*at.*" \
    "break foo"

gdb_test "break baz" \
    "Breakpoint.*at.* file .*$srcfile, line \\d+\\."

gdb_test "continue" \
    "Breakpoint \\d+, foo \\(\\).*" \
    "continue to foo"

gdb_test_no_output "set variable e=1"

# If GDB incorrectly places the foo breakpoint on multiple locations,
# then GDB will (incorrectly) stop in foo_low instead of in baz.
gdb_test "continue" \
    "Breakpoint \\d+, (?:$hex in )?baz \\(\\).*" \
    "continue to baz"

with_test_prefix "step-test-3" {
    clean_restart ${testfile}
    if ![runto_main] {
	return -1
    }

    gdb_test "step" \
	     "foo \\(\\).*bar \\(\\);.*foo bar call.*" \
	     "step into foo from main"

    gdb_test "step" \
	     "bar \\(\\).*\}.* bar end.*" \
	     "step into bar from foo"

    gdb_test "step" \
	     "foo(_label2)? \\(\\).*foo_low \\(\\);.*foo foo_low call.*" \
	     "step out of bar to foo"

    # The tests in the "enable_foo_low_stepping" section, below, work
    # with some versions of gcc, though it's not clear that they
    # should.  This test case causes foo_low, originally a separate
    # function invoked via a subroutine call, to be considered as part
    # of foo via use of DW_AT_ranges.  Real code that I've looked at
    # uses a branch instruction to cause code in the "cold" range to
    # be executed. 
    #
    # For the moment though, these tests have been left in place, but
    # disabled, in case we decide that making such a subroutine call
    # is a reasonable thing to do that should also be supported by
    # GDB.

    set enable_foo_low_stepping false

    if { $enable_foo_low_stepping } {
	gdb_test_no_output "set variable e=1"

	set test "step into foo_low from foo"
	gdb_test_multiple "step" $test {
	    -re "foo(_low)? \\(\\).*\{.*foo_low prologue.*${gdb_prompt}" {
		pass $test
		gdb_test "step" \
			 "foo \\(\\).*baz \\(\\);.*foo_low baz call.*" \
			 "step to baz call in foo_low"

	    }
	    -re "foo(_low)? \\(\\).*baz \\(\\);.*foo_low baz call.*${gdb_prompt}" {
		pass $test
	    }
	}

	gdb_test "step" \
		 "baz \\(\\).*\}.*baz end.*" \
		 "step into baz from foo_low"

	gdb_test "step" \
		 "foo(?:_low(?:_label2)?)? \\(\\).*\}.*foo_low end.*" \
		 "step out of baz to foo_low"

	gdb_test "step" \
		 "foo(?:_label3)? \\(\\).*\}.*foo end.*" \
		 "step out of foo_low to foo"
    } else {
	gdb_test "next" \
		 ".*foo end.*" \
		 "next over foo_low call"
    }

    gdb_test "step" \
	     "main(?:_label2)? \\(\\).*" \
	     "step out of foo to main"
}