[Bug bootstrap/52058] New: [4.7 regression] bootstrap fails on HAVE_cc0: combine.c: 'do_SUBST_LINK' defined but not used

[Bug bootstrap/52058] New: [4.7 regression] bootstrap fails on HAVE_cc0: combine.c: 'do_SUBST_LINK' defined but not used

[mikpe at it dot uu.se]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52058

             Bug #: 52058
           Summary: [4.7 regression] bootstrap fails on HAVE_cc0:
                    combine.c: 'do_SUBST_LINK' defined but not used
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: mikpe@it.uu.se


Attempting to bootstrap gcc-4.7-20120128 on a HAVE_cc0 machine like m68k-linux
fails in stage 2 with:

/mnt/scratch/objdir47/./prev-gcc/xgcc -B/mnt/scratch/objdir47/./prev-gcc/
-B/mnt/scratch/install47/m68k-unknown-linux-gnu/bin/
-B/mnt/scratch/install47/m68k-unknown-linux-gnu/bin/
-B/mnt/scratch/install47/m68k-unknown-linux-gnu/lib/ -isystem
/mnt/scratch/install47/m68k-unknown-linux-gnu/include -isystem
/mnt/scratch/install47/m68k-unknown-linux-gnu/sys-include    -c   -g -O2
-gtoggle -DIN_GCC   -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual
-Wstrict-prototypes -Wmissing-prototypes -Wmissing-format-attribute -pedantic
-Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -Werror
-Wold-style-definition -Wc++-compat   -DHAVE_CONFIG_H -I. -I.
-I/mnt/scratch/gcc-4.7-20120128/gcc -I/mnt/scratch/gcc-4.7-20120128/gcc/.
-I/mnt/scratch/gcc-4.7-20120128/gcc/../include
-I/mnt/scratch/gcc-4.7-20120128/gcc/../libcpp/include
-I/home/mikpe/pkgs/linux-m68k/gmp-5.0.2/include
-I/home/mikpe/pkgs/linux-m68k/mpfr-3.1.0/include
-I/home/mikpe/pkgs/linux-m68k/mpc-0.9/include 
-I/mnt/scratch/gcc-4.7-20120128/gcc/../libdecnumber
-I/mnt/scratch/gcc-4.7-20120128/gcc/../libdecnumber/dpd -I../libdecnumber   
/mnt/scratch/gcc-4.7-20120128/gcc/combine.c -o combine.o
/mnt/scratch/gcc-4.7-20120128/gcc/combine.c:796:1: error: 'do_SUBST_LINK'
defined but not used [-Werror=unused-function]
cc1: all warnings being treated as errors

make[3]: *** [combine.o] Error 1
make[3]: Leaving directory `/mnt/scratch/objdir47/gcc'
make[2]: *** [all-stage2-gcc] Error 2
make[2]: Leaving directory `/mnt/scratch/objdir47'
make[1]: *** [stage2-bubble] Error 2
make[1]: Leaving directory `/mnt/scratch/objdir47'
make: *** [bootstrap] Error 2

This is because the PR rtl-optimization/48308 fix in r183512 added an
unconditional definition of do_SUBST_LINK, but it's used #ifndef HAVE_cc0.

The definition could also be made #ifndef HAVE_cc0, but a cleaner solution
perhaps is to mark it ATTRIBUTE_UNUSED:

--- gcc-4.7-20120128/gcc/combine.c.~1~  2012-01-25 09:52:39.000000000 +0100
+++ gcc-4.7-20120128/gcc/combine.c      2012-01-30 20:57:54.000000000 +0100
@@ -792,7 +792,7 @@ do_SUBST_MODE (rtx *into, enum machine_m

 /* Similar to SUBST, but NEWVAL is a LOG_LINKS expression.  */

-static void
+static void ATTRIBUTE_UNUSED
 do_SUBST_LINK (struct insn_link **into, struct insn_link *newval)
 {
   struct undo *buf;

With this fix my bootstrap does get past stage 2 combine.c.

[Bug bootstrap/52058] [4.7 regression] bootstrap fails on HAVE_cc0: combine.c: 'do_SUBST_LINK' defined but not used

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52058

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-01-31
   Target Milestone|---                         |4.7.0
     Ever Confirmed|0                           |1

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-31 10:49:07 UTC ---
Or guarded in

#ifndef HAVE_cc0

[Bug bootstrap/52058] [4.7 regression] bootstrap fails on HAVE_cc0: combine.c: 'do_SUBST_LINK' defined but not used

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52058

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-01-31 16:08:56 UTC ---
Author: jakub
Date: Tue Jan 31 16:08:47 2012
New Revision: 183763

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=183763
Log:
    PR bootstrap/52058
    * combine.c (do_SUBST_LINK, SUBST_LINK): Guard with #ifndef HAVE_cc0.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/combine.c

[Bug bootstrap/52058] [4.7 regression] bootstrap fails on HAVE_cc0: combine.c: 'do_SUBST_LINK' defined but not used

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52058

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |jakub at gcc dot gnu.org
         Resolution|                            |FIXED

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-01-31 16:11:06 UTC ---
Fixed.