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PR 16711 noted that gold allocates file space for BSS sections when using a linker script. I've fixed that by rewriting set_section_addresses and set_section_list_addresses to track the file offset separate from the current virtual address, so that BSS sections do not move the file offset. Now, if a series of BSS sections come at the end of a segment, we do not allocate file space; but if a script forces them into the middle of a segment, we will still allocate file space (matching Gnu ld behavior). I've also added a warning when that happens. That exposed another problem where orphan .bss sections were sometimes placed in the middle of a segment. For example, if the script mentions the .got section, but both .data and .bss are orphans, gold would put both .data and .bss in front of .got. I've fixed that by ensuring that orphan BSS sections are always placed after all other allocated sections. It also exposed a problem where the SUBALIGN property is not handled properly. The ld manual clearly states that it should override input section alignment, whether greater or less than the given alignment, but gold would only increase an input section's alignment. Gold would also place the output section based on its original alignment before the SUBALIGN property took effect, leading to a misaligned output section (where the input section was properly aligned in memory, but was not aligned relative to the start of the section), in violation of the ELF/gABI spec. I've fixed that by making sure that the SUBALIGN property overrides the internal alignment of the input sections as well as the external alignment of the output section. This affected the behavior of script_test_2, which was written to expect a misaligned section. The net effect is, I think, improved compatibility with the BFD linker. There are still cases where orphan placement differs, but the differences should be rarer and less important. ALIGN and SUBALIGN behavior is closer, but still not an exact match -- I still found cases where ld would create a misaligned output section, and where gold will properly align it. gold/ PR gold/16711 * output.cc (Output_section::set_final_data_size): Calculate data size based on relative offset rather than file offset. (Output_segment::set_section_addresses): Track file offset separately from address offset. (Output_segment::set_section_list_addresses): Add pfoff parameter. Track file offset separately. Don't move file offset for BSS sections. * output.h (Output_segment::set_section_list_addresses): Add pfoff parameter. * script-sections.cc (Orphan_section_placement): Add PLACE_LAST_ALLOC. (Orphan_section_placement::Orphan_section_placement): Initialize it. (Orphan_section_placement::output_section_init): Track last allocated section. (Orphan_section_placement::find_place): Place BSS after last allocated section. (Output_section_element_input::set_section_addresses): Always override input section alignment when SUBALIGN is specified. (Output_section_definition::set_section_addresses): Override alignment of output section when SUBALIGN is specified. * testsuite/Makefile.am (script_test_15a, script_test_15b) (script_test_15c): New test cases. * testsuite/Makefile.in: Regenerate. * testsuite/script_test_2.cc: Adjust expected layout. * testsuite/script_test_15.c: New source file. * testsuite/script_test_15a.sh: New shell script. * testsuite/script_test_15a.t: New linker script. * testsuite/script_test_15b.sh: New shell script. * testsuite/script_test_15b.t: New linker script. * testsuite/script_test_15c.sh: New shell script. * testsuite/script_test_15c.t: New linker script. |
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bfd | ||
binutils | ||
config | ||
cpu | ||
elfcpp | ||
etc | ||
gas | ||
gdb | ||
gold | ||
gprof | ||
include | ||
intl | ||
ld | ||
libdecnumber | ||
libiberty | ||
opcodes | ||
readline | ||
sim | ||
texinfo | ||
zlib | ||
.cvsignore | ||
.gitattributes | ||
.gitignore | ||
ChangeLog | ||
compile | ||
config-ml.in | ||
config.guess | ||
config.rpath | ||
config.sub | ||
configure | ||
configure.ac | ||
COPYING | ||
COPYING3 | ||
COPYING3.LIB | ||
COPYING.LIB | ||
COPYING.LIBGLOSS | ||
COPYING.NEWLIB | ||
depcomp | ||
djunpack.bat | ||
install-sh | ||
libtool.m4 | ||
lt~obsolete.m4 | ||
ltgcc.m4 | ||
ltmain.sh | ||
ltoptions.m4 | ||
ltsugar.m4 | ||
ltversion.m4 | ||
MAINTAINERS | ||
Makefile.def | ||
Makefile.in | ||
Makefile.tpl | ||
makefile.vms | ||
missing | ||
mkdep | ||
mkinstalldirs | ||
move-if-change | ||
README | ||
README-maintainer-mode | ||
setup.com | ||
src-release.sh | ||
symlink-tree | ||
ylwrap |
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.