[Bug lto/47188] New: Undefined reference errors when combining IR and non-IR object files

[Bug lto/47188] New: Undefined reference errors when combining IR and non-IR object files

[d.g.gorbachev at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47188

           Summary: Undefined reference errors when combining IR and
                    non-IR object files
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: d.g.gorbachev@gmail.com


Created attachment 22912
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22912
Testcase

Re: [Bug lto/47188] New: Undefined reference errors when combining IR and non-IR object files

[Jan Hubicka]

The bug seems to be that lto-symtab incorrectly sets resolution info of the callgraph node as unknown.  Looking into it.

Honza

[Bug lto/47188] Undefined reference errors when combining IR and non-IR object files

[hubicka at ucw dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47188

--- Comment #1 from Jan Hubicka <hubicka at ucw dot cz> 2011-01-06 13:18:03 UTC ---
The bug seems to be that lto-symtab incorrectly sets resolution info of the
callgraph node as unknown.  Looking into it.

Honza

Re: [Bug lto/47188] Undefined reference errors when combining IR and non-IR object files

[Jan Hubicka]

This is driver bug.  With -flto-partition=none it for whatever reason forgets about -fresolution:

 ../lto1 -quiet -dumpdir ./ -dumpbase prog -mtune=generic -march=x86-64 -auxbase-strip /tmp/cctgIO6R.lto.o -version -flto-partition=none -fuse-linker-plugin -fwhole-program -fdump-ipa-all-details @/tmp/ccpDD04R -o foo.s 

Re: [Bug lto/47188] Undefined reference errors when combining IR and non-IR object files

[Jan Hubicka]

The problem is that collect2 should be in LTO_MODE_NONE when plugin is used but
it confuses itself and sets itself into LTO_MODE_LTO. Consequently compilation
is done twice, once correctly with plugin and then once again with collect2
path. 

I am testing the attached patch.  It will also make non-WHOPR mode twice as fast ;))

Honza

Index: collect2.c
===================================================================
--- collect2.c	(revision 168508)
+++ collect2.c	(working copy)
@@ -1236,7 +1236,7 @@ main (int argc, char **argv)
 #endif
       }
     vflag = debug;
-    if (no_partition)
+    if (no_partition && lto_mode == LTO_MODE_WHOPR)
       lto_mode = LTO_MODE_LTO;
   }
 

[Bug lto/47188] Undefined reference errors when combining IR and non-IR object files

[hubicka at ucw dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47188

--- Comment #2 from Jan Hubicka <hubicka at ucw dot cz> 2011-01-06 13:31:36 UTC ---
This is driver bug.  With -flto-partition=none it for whatever reason forgets
about -fresolution:

 ../lto1 -quiet -dumpdir ./ -dumpbase prog -mtune=generic -march=x86-64
-auxbase-strip /tmp/cctgIO6R.lto.o -version -flto-partition=none
-fuse-linker-plugin -fwhole-program -fdump-ipa-all-details @/tmp/ccpDD04R -o
foo.s

[Bug lto/47188] Undefined reference errors when combining IR and non-IR object files

[hubicka at ucw dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47188

--- Comment #3 from Jan Hubicka <hubicka at ucw dot cz> 2011-01-06 13:44:09 UTC ---
The problem is that collect2 should be in LTO_MODE_NONE when plugin is used but
it confuses itself and sets itself into LTO_MODE_LTO. Consequently compilation
is done twice, once correctly with plugin and then once again with collect2
path. 

I am testing the attached patch.  It will also make non-WHOPR mode twice as
fast ;))

Honza

Index: collect2.c
===================================================================
--- collect2.c    (revision 168508)
+++ collect2.c    (working copy)
@@ -1236,7 +1236,7 @@ main (int argc, char **argv)
 #endif
       }
     vflag = debug;
-    if (no_partition)
+    if (no_partition && lto_mode == LTO_MODE_WHOPR)
       lto_mode = LTO_MODE_LTO;
   }

[Bug lto/47188] Undefined reference errors when combining IR and non-IR object files

[d.g.gorbachev at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47188

--- Comment #4 from Dmitry Gorbachev <d.g.gorbachev at gmail dot com> 2011-01-06 14:45:17 UTC ---
Collect2-based LTO (when CFLAGS = -flto -fwhole-program) fails, too.

[Bug lto/47188] Undefined reference errors when combining IR and non-IR object files

[hubicka at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47188

--- Comment #5 from Jan Hubicka <hubicka at gcc dot gnu.org> 2011-01-06 18:50:22 UTC ---
Author: hubicka
Date: Thu Jan  6 18:50:20 2011
New Revision: 168548

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=168548
Log:

    PR lto/47188
    * collect2.c (main): Do not enable LTOmode when plugin is active.
    * testsuite/gcc.dg/lto/pr47188_0.c: New testcase.
    * testsuite/gcc.dg/lto/pr47188_1.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/lto/pr47188_0.c
    trunk/gcc/testsuite/gcc.dg/lto/pr47188_1.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/collect2.c
    trunk/gcc/testsuite/ChangeLog

[Bug lto/47188] Undefined reference errors when combining IR and non-IR object files

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47188

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED

--- Comment #6 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-01-11 12:11:18 UTC ---
Fixed.