# Test that the linker reports undefined symbol errors correctly.
# By Ian Lance Taylor, Cygnus Support
#
# Copyright (C) 1995-2020 Free Software Foundation, Inc.
#
# This file is part of the GNU Binutils.
#
# 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, write to the Free Software
# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
# MA 02110-1301, USA.
set testund "undefined"
set testfn "undefined function"
set testline "undefined line"
if { ![check_compiler_available] } {
verbose "Could not find C compiler!" 1
untested $testund
untested $testfn
untested $testline
} elseif { ![ld_compile "$CC -g" $srcdir/$subdir/undefined.c tmpdir/undefined.o] } {
verbose "Unable to compile test file!" 1
unresolved $testund
unresolved $testfn
unresolved $testline
} else {
remote_file host delete "tmpdir/undefined"
set flags [big_or_little_endian]
# Using -e start prevents the SunOS linker from trying to build a
# shared library. But don't use an entry point in BPF targets.
switch -glob $target_triplet {
bpf-*-* { set entry "" }
* { set entry "-e start" }
}
send_log "$ld $entry $flags -o tmpdir/undefined tmpdir/undefined.o\n"
set exec_output [run_host_cmd "$ld" "$entry $flags -o tmpdir/undefined tmpdir/undefined.o"]
send_log "$exec_output\n"
verbose "$exec_output"
proc checkund { string testname } {
global exec_output
if [string match "*$string*" $exec_output] {
pass $testname
} else {
fail $testname
}
}
set mu "undefined reference to `*this_function_is_not_defined'"
checkund $mu $testund
# ARM PE defaults to using stabs debugging, which we can't handle
# for a COFF file.
#setup_xfail "arm*-*-pe*"
# For Xtensa on GNU Linux systems (or any other system where PIC
# code is always used), the address of the undefined function is
# in a literal pool outside the function, so that both the
# "undefined function" and "undefined line" tests fail.
setup_xfail xtensa*-*-linux*
set mf "tmpdir/undefined.o* in function `function':"
checkund $mf $testfn
if ![is_elf_format] {
# COFF SH gets this test wrong--it reports line 10, because
# although the jump is at line 9, the function address, and
# the reloc, is stored at the end of the function.
setup_xfail "sh-*-*"
# ARM PE defaults to using stabs debugging, which we can't
# handle for a COFF file.
#setup_xfail "arm*-*-pe*"
}
set ml "undefined.c:9: undefined reference to `*this_function_is_not_defined'"
# With targets that use elf/dwarf2, such as the arm-elf toolchain,
# the code in bfd/elf.c:_bfd_elf_find_nearest_line() is called in
# order to locate the file name/line number where the undefined
# reference occurs. Unfortunately this tries to use the dwarf2
# debug information held in the .debug_info section. This section
# contains a series of comp_unit structures, each of which has a
# low/high address range representing the span of memory locations
# covered by that structure. The structures also index into other
# structures held in the .debug_line section and together they can
# translate memory locations back into file/function/line number
# addresses in the source code. Since the information about the
# memory region covered by a comp_unit is only determined at link
# time, the low/high addresses in the .debug_info section and the
# line addresses in the .debug_line section are computed by
# generating relocs against known symbols in the object code.
#
# When the undefined reference is detected, the relocs in the
# dwarf2 debug sections have not yet been resolved, so the
# low/high addresses and the line number address are all set at
# zero. Thus when _bfd_elf_find_nearest_line() calls
# _bfd_dwarf2_find_nearest_line() no comp_unit can be found which
# actually covers the address where the reference occurred, and so
# _bfd_elf_find_nearest_line() fails.
#
# The upshot of all of this, is that the error message reported by
# the linker, instead of having a source file name & line number
# as in:
#
# undefined.c:9: undefined reference to `this_function_is_not_defined'
#
# has an object file & section address instead:
#
# undefined.0(.text+0xc): undefined reference to `this_function_is_not_defined'
#
# hence the xfails below.
setup_xfail mcore-*-elf
setup_xfail mep-*-*
setup_xfail mips-sgi-irix6*
# Fails for the MSP430 because it uses SYM_DIFF relocs but it does
# not provide a special_function for handling them. If
# optimization is enabled then this test passes because
# function()'s prologue is eliminated.
setup_xfail "msp430-*-*"
# The undefined test fails on 31 bit s/390 because the address of
# the function `this_function_is_not_defined' is stored in the
# literal pool of the function. Therefore the line number in the
# error message is 8 instead of 9. On 64 bit s/390 this works
# because of the new brasl instruction that doesn't need a literal
# pool entry.
setup_xfail s390-*-*
# See comments above for Xtensa.
setup_xfail xtensa*-*-linux*
setup_xfail hppa*64*-*-*
# eBPF doesn't support dwarf yet.
setup_xfail bpf-*-*
checkund $ml $testline
}
# Undefined symbols should become dynamic when linking a shared lib.
set testname "undefined symbols in shared lib"
set asflags ""
switch -glob $target_triplet {
aarch64* -
arm* -
powerpc64* { set asflags "--defsym BL=1" }
powerpc* { set asflags "--defsym BLPLT=1" }
hppa* { set asflags "--defsym HPPA=1" }
i\[3-7\]86* -
x86_64* { set asflags "--defsym CALLPLT=1" }
}
if { ![is_elf_format] || ![check_shared_lib_support]} then {
unsupported $testname
} elseif {![ld_assemble $as "$asflags $srcdir/$subdir/fundef.s" \
tmpdir/fundef.o]} then {
fail $testname
} elseif {![ld_link $ld tmpdir/fundef.so \
"-shared --allow-shlib-undefined tmpdir/fundef.o"]} then {
setup_xfail tic6x-*-*
fail $testname
} else {
if {![is_remote host] && [which $nm] == 0} then {
unresolved "$testname (dyn sym)"
} else {
set exec_output [run_host_cmd "$nm" "-D tmpdir/fundef.so"]
set exec_output [prune_warnings $exec_output]
if { ($asflags == ""
|| ([regexp ".* undef_fun_typed.*" $exec_output]
&& [regexp ".* undef_fun_notype.*" $exec_output]))
&& [regexp ".* undef_data.*" $exec_output]
&& [regexp ".* undef_pfun.*" $exec_output]
&& [regexp ".* undef_notype.*" $exec_output]} then {
pass "$testname (dyn sym)"
} else {
fail "$testname (dyn sym)"
}
}
global READELF
if {![is_remote host] && [which $READELF] == 0} then {
unresolved "$testname (dyn reloc)"
} else {
set exec_output [run_host_cmd "$READELF" "-r tmpdir/fundef.so"]
set exec_output [prune_warnings $exec_output]
# We ought to get two .rel{a}.plt and three .rel{a}.dyn relocs,
# except for MIPS targets whose psABI mandates an extra
# R_MIPS_NONE relocation, also used to pad n64 relocation
# triplets, and S+core targets using an extra R_SCORE_NONE
# relocation, so adjust for that.
switch -glob $target_triplet {
"mips64*-*-openbsd*" {
set none_count 6
set reloc_count 4
}
"mips*" -
"score*" {
set none_count 1
set reloc_count 4
}
"*" {
set none_count 0
set reloc_count 3
}
}
if { ($asflags == "" || [regexp ".* contains 2 .*" $exec_output])
&& [regexp ".* contains $reloc_count .*" $exec_output]
&& [regexp -all "_NONE" $exec_output] == $none_count } then {
pass "$testname (dyn reloc)"
} else {
fail "$testname (dyn reloc)"
}
}
}