| #! @PERL@ |
| |
| # This script handles linking the tool executables on Linux, |
| # statically and at an alternative load address. |
| # |
| # Linking statically sidesteps all sorts of complications to do with |
| # having two copies of the dynamic linker (valgrind's and the |
| # client's) coexisting in the same process. The alternative load |
| # address is needed because Valgrind itself will load the client at |
| # whatever address it specifies, which is almost invariably the |
| # default load address. Hence we can't allow Valgrind itself (viz, |
| # the tool executable) to be loaded at that address. |
| # |
| # Unfortunately there's no standard way to do 'static link at |
| # alternative address', so these link_tool_exe_*.in scripts handle |
| # the per-platform hoop-jumping. |
| # |
| # What we get passed here is: |
| # first arg |
| # the alternative load address |
| # all the rest of the args |
| # the gcc invokation to do the final link, that |
| # the build system would have done, left to itself |
| # |
| # We just let the script 'die' if something is wrong, rather than do |
| # proper error reporting. We don't expect the users to run this |
| # directly. It is only run as part of the build process, with |
| # carefully constrained inputs. |
| # |
| # Linux specific complications: |
| # |
| # - need to support both old GNU ld and gold: use -Ttext= to |
| # set the text segment address if that is all we have. We really |
| # need -Ttext-segment. Otherwise with GNU ld sections or notes |
| # (like the build-id) don't get at the desired address. But older |
| # linkers only know about -Ttext, not -Ttext-segment. So configure |
| # checks for us and sets FLAG_T_TEXT. |
| # |
| # - If all we have is -Ttext, then we need to pass --build-id=none |
| # (that is, -Wl,--build-id=none to gcc) if it accepts it, to ensure |
| # the linker doesn't add a notes section which ends up at the default |
| # load address and so defeats our attempts to keep that address clear |
| # for the client. However, older linkers don't support this flag, |
| # so it is tested for by configure.in and is shipped to us as part of |
| # argv[2 ..]. |
| # |
| # So: what we actually do: |
| # |
| # pass the specified command to the linker as-is, except, add |
| # "-static" and "-Ttext[-segment]=<argv[1]>" to it. |
| # Previously we did this by adding these options after the first |
| # word of the rest of the arguments, which works in the common case |
| # when it's something like "gcc". But the linker invocation itself |
| # might be multiple words, say if it's "ccache gcc". So we now put |
| # the new options at the end instead. |
| # |
| |
| use warnings; |
| use strict; |
| |
| # expect at least: alt-load-address gcc -o foo bar.o |
| die "Not enough arguments" |
| if (($#ARGV + 1) < 5); |
| |
| my $ala = $ARGV[0]; |
| shift; # Remove $ala from @ARGV |
| |
| # check for plausible-ish alt load address |
| die "Bogus alt-load address" |
| if (length($ala) < 3 || index($ala, "0x") != 0); |
| |
| # For mips32 or mips64 we need to use "--section-start=.reginfo=$ala" or |
| # "--section-start=.MIPS.options=$ala" respectively, because "-Ttext=$ala" will |
| # not put all the sections to the specificed address ($ala). |
| my $x = `cat ../config.log 2>&1 | grep host_cpu= | sed "s/host_cpu='//g"`; |
| my $arch = substr($x, 0, index($x, "'")); |
| |
| my $extra_args; |
| if (($arch eq 'mips') || ($arch eq 'mipsel') |
| || ($arch eq 'mipsisa32r2el')) { |
| $extra_args = "-static -Wl,--section-start=.reginfo=$ala"; |
| } elsif (($arch eq 'mips64') || ($arch eq 'mips64el') || |
| ($arch eq 'mipsisa64el')) { |
| $extra_args = "-static -Wl,--section-start=.MIPS.options=$ala"; |
| } else { |
| $extra_args = "-static -Wl,@FLAG_T_TEXT@=$ala"; |
| } |
| |
| my $cmd = join(" ", @ARGV, $extra_args); |
| |
| #print "link_tool_exe_linux: $cmd\n"; |
| |
| |
| # Execute the command: |
| my $r = system($cmd); |
| |
| if ($r == 0) { |
| exit 0; |
| } else { |
| exit 1; |
| } |