[Bug ld/2342] linkonce debug is broken
--- Additional Comments From hjl at lucon dot org 2006-05-24 15:51 --- Fixed by http://sourceware.org/ml/binutils/2006-05/msg00183.html -- What|Removed |Added Status|NEW |RESOLVED Resolution||FIXED http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
--- Additional Comments From hjl at lucon dot org 2006-04-25 03:23 --- Here is the patch to speed it up: http://sourceware.org/ml/binutils/2006-04/msg00329.html -- http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
--- Additional Comments From matz at suse dot de 2006-04-24 15:22 --- Created an attachment (id=979) --> (http://sourceware.org/bugzilla/attachment.cgi?id=979&action=view) A small hack which can be applied. So this is a more complete patch which works for us. For now we tested only the testsuite and the huge tarball, not any packages. -- http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
--- Additional Comments From matz at suse dot de 2006-04-24 15:17 --- 10 minutes was the worst I think, with the tarball (it might be that it's not synced yet, I don't know how often the webserver does that). -- http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
-- What|Removed |Added CC||matz at suse dot de http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
--- Additional Comments From hjl at lucon dot org 2006-04-24 15:02 --- How often does it happen? What is the worst case link time you have seen so far? -- http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
--- Additional Comments From matz at suse dot de 2006-04-24 14:33 --- Btw, HJ: your patch to revert Alans also makes ld quite slow on huge testcases. I put a tarball on http://www.suse.de/~gcctest/slowld.tar.gz . link command: % g++ -g -o ff3d trapFPE.o main.o FFThread.o StaticCenter.o language/libfflanguage.a solver/libffsolve.a language/libpovlanguage.a geometry/libffgeometry.a algebra/libffalgebra.a utils/libffutils.a -pthread This will take from five to ten minutes to link depending on the machine. These are i386 .o and .a files. The problem is that _bfd_elf_check_kept_section is N^2 in the number of sections, and furthermore does repeatedly the same work over and over again (e.g. sorting all symbols of a BFD over and over). Not having PRETEND in action completely avoids this work here (though of course the N^2 problem still is there). This reduces link time to about 2 to 3 seconds. We were trying to work-around this by noting that the _bfd_elf_check_kept_section() function basically is const, i.e. given the same discared input section it will give the same result every time. Hence we can remember it in struct bfd_section or in the ELF specific part of a section. That still leavs multiple sorts over the same set of symbols for each BFD (one time for each section needing that handling). Then ld needs only 17 seconds, which still is much better. When I saw that this actually was not a problem in FSF binutils, but only in your version I stopped making the patch pretty for submission, so I add it here only for demonstration what I mean: -- @@ -7512,7 +7438,13 @@ elf_link_input_bfd (struct elf_final_lin { asection *kept; - kept = _bfd_elf_check_kept_section (sec); + if (sec->hack_foo == NULL) + { + sec->hack_foo = _bfd_elf_check_kept_section (sec); + } + if (sec->hack_foo == NULL) + sec->hack_foo = (void*)-1; + kept = sec->hack_foo == (void*)-1 ? NULL : sec->hack_foo; if (kept != NULL) { *ps = kept; - Probably can't be applied due to white-space changes. Also add a 'hack_foo' member to asection ;-) Perhaps you might use that idea in your reversal patch to make HJ binutils not as slow. Another thing I noticed while reading the code is some obvious funnyness in match_group_member(), which read like so: match_group_member (asection *sec, asection *group) { asection *first = elf_next_in_group (group); asection *s = first; while (s != NULL) { if (bfd_elf_match_symbols_in_sections (s, sec)) return s; if (s == first) break; } return NULL; } This obviously was designed to loop over all sections in a section group, when provided with one. The loop structure and use of elf_next_in_group indicate this. But this loop actually doesn't iterate, as "s" never is changed. -- http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
--- Additional Comments From amodra at bigpond dot net dot au 2006-02-16 04:56 --- As I said, I haven't found a testcase that fails on x86.. The ppc64 compiler is Target: powerpc-linux Configured with: /src/gcc-current/configure --prefix=/usr/local --build=powerpc-linux --host=powerpc-linux --target=powerpc-linux --enable-targets=powerpc64-linux --with-cpu=default64 --disable-nls --enable-__cxa_atexit --enable-languages=all Thread model: posix gcc version 4.2.0 20060213 (experimental) -- http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
--- Additional Comments From hjl at lucon dot org 2006-02-16 05:45 --- Since my testcase works on x86, but fails on ppc64, can you compare the output of "readelf -w" bewteen x86 and ppc64? The problem you have seen may be specific to ppc64 in ld, gcc and/or gdb. -- http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
--- Additional Comments From hjl at lucon dot org 2006-02-16 01:43 --- On x86, the linker without your change gave me (gdb) b foo1 Breakpoint 1 at 0x80484a7: file test01b.cpp, line 5. (gdb) r Starting program: /export/home/hjl/bugs/binutils/linkonce/test Breakpoint 1, foo1 (b=1) at test01b.cpp:5 5B *pb= new B ; (gdb) What compiler are you using? Why doesn't it fail on x86? -- http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
--- Additional Comments From amodra at bigpond dot net dot au 2006-02-16 00:47 --- At least, I haven't managed to generate a testcase that fails on x86. On powerpc64-linux, the testcase you have here also shows the problem I saw with the oracle app. With debug info for removed linkonce pointing to kept (gdb) b foo1 Breakpoint 1 at 0x1734: file test01c.cpp, line 4. With debug info for removed linkonce zeroed (gdb) b foo1 Breakpoint 1 at 0x1734: file test01b.cpp, line 5. -- http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
--- Additional Comments From amodra at bigpond dot net dot au 2006-02-16 00:39 --- The problem occurred in debugging a huge C++ oracle application, using current CVS gdb as well as older gdbs. My attempts to generate a reduced testcase have so far failed. -- http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
--- Additional Comments From hjl at lucon dot org 2006-02-15 23:50 --- I know my patch isn't ideal. But at least, it fixes the testcase with gdb and your change fails it. Do you have a testcase to show the gdb problem you are trying to address? We can try to make both testcases to work correctly with gdb by modifying ld/gdb or both. BTW, I am using gdb 6.4.50.20060201-cvs. -- What|Removed |Added GCC build triplet||i686-pc-linux-gnu GCC host triplet||i686-pc-linux-gnu GCC target triplet||i686-pc-linux-gnu http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
--- Additional Comments From amodra at bigpond dot net dot au 2006-02-15 23:06 --- I think we all agree that the ideal ld behaviour would be to strip out debug info corresponding to removed linkonce sections. Failing that, I claim that marking the debug info in some way as invalid is the next best solution. At least that gives gdb a chance to discard the info. That is what we are trying to do by putting a zero in debug info address fields. Your patch caused other gdb problems, specifically, gdb miscalculated the address range for a compilation unit, which led to gdb reporting file and line number wrongly for a breakpoint set in another compilation unit. -- http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/2342] linkonce debug is broken
--- Additional Comments From hjl at lucon dot org 2006-02-15 22:19 --- Created an attachment (id=868) --> (http://sourceware.org/bugzilla/attachment.cgi?id=868&action=view) A testcase The old linker: [EMAIL PROTECTED] xx]$ make g++ -g -c -o test01a.o test01a.cpp g++ -g -c -o test01b.o test01b.cpp g++ -g -c -o test01c.o test01c.cpp ld -r -o test.o test01a.o test01b.o test01c.o g++ -g -o test test.o gdb -batch -x gdb.cmd test > gdb.log Function "internal_error" not defined. Function "info_command" not defined. .gdbinit:8: Error in sourced command file: No breakpoint number 0. bp2=`grep -i Breakpoint gdb.log | grep test01a.h | grep "line 4"` || exit 1; \ echo $bp2 | grep 0x0:; \ if [ $? = 0 ]; then exit 1; else true; fi [EMAIL PROTECTED] xx]$ The new linker: [EMAIL PROTECTED] xx]$ make LD=../ld g++ -g -c -o test01a.o test01a.cpp g++ -g -c -o test01b.o test01b.cpp g++ -g -c -o test01c.o test01c.cpp ../ld -r -o test.o test01a.o test01b.o test01c.o g++ -g -o test test.o gdb -batch -x gdb.cmd test > gdb.log Function "internal_error" not defined. Function "info_command" not defined. .gdbinit:8: Error in sourced command file: No breakpoint number 0. bp2=`grep -i Breakpoint gdb.log | grep test01a.h | grep "line 4"` || exit 1; \ echo $bp2 | grep 0x0:; \ if [ $? = 0 ]; then exit 1; else true; fi Breakpoint 2 at 0x0: file test01a.h, line 4. make: *** [all] Error 1 [EMAIL PROTECTED] xx]$ -- http://sourceware.org/bugzilla/show_bug.cgi?id=2342 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils