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: unassig...@gcc.gnu.org ReportedBy: mi...@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.