# Test that the linker reports undefined symbol errors correctly. # By Ian Lance Taylor, Cygnus Support # # Copyright (C) 1995-2017 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 { ![is_remote host] && [which $CC] == 0 } { verbose "Could not find C compiler!" 1 untested $testund untested $testfn untested $testline return } if ![ld_compile "$CC -g" $srcdir/$subdir/undefined.c tmpdir/undefined.o] { verbose "Unable to compile test file!" 1 unresolved $testund unresolved $testfn unresolved $testline return } remote_file host delete "tmpdir/undefined" set flags [big_or_little_endian] # Using -e start prevents the SunOS linker from trying to build a # shared library. send_log "$ld -e start $flags -o tmpdir/undefined tmpdir/undefined.o\n" set exec_output [run_host_cmd "$ld" "-e start $flags -o tmpdir/undefined tmpdir/undefined.o"] send_log "$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* setup_xfail "sh64-*-*" # 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*-*-* checkund $ml $testline