[Bug bootstrap/57340] New: [4.9 regression] stage2 miscompiles build/genconditions on armv5tel-linux-gnueabi breaking bootstrap

[mikpe at it dot uu.se]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57340

            Bug ID: 57340
           Summary: [4.9 regression] stage2 miscompiles
                    build/genconditions on armv5tel-linux-gnueabi breaking
                    bootstrap
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mikpe at it dot uu.se

Attempting to bootstrap gcc-4.9-20130519 on armv5tel-linux-gnueabi fails with:

/mnt/scratch/objdir49/./prev-gcc/xg++ -B/mnt/scratch/objdir49/./prev-gcc/
-B/mnt/scratch/install49/armv5tel-unknown-linux-gnueabi/bin/ -nostdinc++
-B/mnt/scratch/objdir49/prev-armv5tel-unknown-linux-gnueabi/libstdc++-v3/src/.libs
-B/mnt/scratch/objdir49/prev-armv5tel-unknown-linux-gnueabi/libstdc++-v3/libsupc++/.libs
-I/mnt/scratch/objdir49/prev-armv5tel-unknown-linux-gnueabi/libstdc++-v3/include/armv5tel-unknown-linux-gnueabi
-I/mnt/scratch/objdir49/prev-armv5tel-unknown-linux-gnueabi/libstdc++-v3/include
-I/mnt/scratch/gcc-4.9-20130519/libstdc++-v3/libsupc++
-L/mnt/scratch/objdir49/prev-armv5tel-unknown-linux-gnueabi/libstdc++-v3/src/.libs
-L/mnt/scratch/objdir49/prev-armv5tel-unknown-linux-gnueabi/libstdc++-v3/libsupc++/.libs
-c   -g -O2 -gtoggle -DIN_GCC   -fno-exceptions -fno-rtti
-fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings
-Wcast-qual -Wmissing-format-attribute -pedantic -Wno-long-long
-Wno-variadic-macros -Wno-overlength-strings -Werror   -DHAVE_CONFIG_H
-DGENERATOR_FILE -I. -Ibuild -I/mnt/scratch/gcc-4.9-20130519/gcc
-I/mnt/scratch/gcc-4.9-20130519/gcc/build
-I/mnt/scratch/gcc-4.9-20130519/gcc/../include
-I/mnt/scratch/gcc-4.9-20130519/gcc/../libcpp/include 
-I/mnt/scratch/gcc-4.9-20130519/gcc/../libdecnumber
-I/mnt/scratch/gcc-4.9-20130519/gcc/../libdecnumber/dpd -I../libdecnumber
-I/mnt/scratch/gcc-4.9-20130519/gcc/../libbacktrace    \
        -o build/genconditions.o
/mnt/scratch/gcc-4.9-20130519/gcc/genconditions.c
/mnt/scratch/objdir49/./prev-gcc/xg++ -B/mnt/scratch/objdir49/./prev-gcc/
-B/mnt/scratch/install49/armv5tel-unknown-linux-gnueabi/bin/ -nostdinc++
-B/mnt/scratch/objdir49/prev-armv5tel-unknown-linux-gnueabi/libstdc++-v3/src/.libs
-B/mnt/scratch/objdir49/prev-armv5tel-unknown-linux-gnueabi/libstdc++-v3/libsupc++/.libs
-I/mnt/scratch/objdir49/prev-armv5tel-unknown-linux-gnueabi/libstdc++-v3/include/armv5tel-unknown-linux-gnueabi
-I/mnt/scratch/objdir49/prev-armv5tel-unknown-linux-gnueabi/libstdc++-v3/include
-I/mnt/scratch/gcc-4.9-20130519/libstdc++-v3/libsupc++
-L/mnt/scratch/objdir49/prev-armv5tel-unknown-linux-gnueabi/libstdc++-v3/src/.libs
-L/mnt/scratch/objdir49/prev-armv5tel-unknown-linux-gnueabi/libstdc++-v3/libsupc++/.libs
  -g -O2 -gtoggle -DIN_GCC   -fno-exceptions -fno-rtti
-fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings
-Wcast-qual -Wmissing-format-attribute -pedantic -Wno-long-long
-Wno-variadic-macros -Wno-overlength-strings -Werror   -DHAVE_CONFIG_H
-DGENERATOR_FILE -static-libstdc++ -static-libgcc  -o build/genconditions \
    build/genconditions.o build/rtl.o build/read-rtl.o build/ggc-none.o
build/vec.o build/min-insn-modes.o build/gensupport.o build/print-rtl.o
build/read-md.o build/errors.o .././libiberty/libiberty.a
build/genconditions /mnt/scratch/gcc-4.9-20130519/gcc/config/arm/arm.md >
tmp-condmd.c
/bin/sh: line 1:  4055 Segmentation fault      build/genconditions
/mnt/scratch/gcc-4.9-20130519/gcc/config/arm/arm.md > tmp-condmd.c
make[3]: *** [s-conditions] Error 139
make[3]: Leaving directory `/mnt/scratch/objdir49/gcc'
make[2]: *** [all-stage2-gcc] Error 2
make[2]: Leaving directory `/mnt/scratch/objdir49'
make[1]: *** [stage2-bubble] Error 2
make[1]: Leaving directory `/mnt/scratch/objdir49'
make: *** [bootstrap] Error 2

Running it in gdb it seems to have followed a NULL function pointer or code
label:

> cd gcc
> gdb build/genconditions
...
(gdb) run /mnt/scratch/gcc-4.9-20130519/gcc/config/arm/arm.md > tmp-condmd.c
Starting program: /mnt/scratch/objdir49/gcc/build/genconditions
/mnt/scratch/gcc-4.9-20130519/gcc/config/arm/arm.md > tmp-condmd.c

Program received signal SIGSEGV, Segmentation fault.
0x00000000 in ?? ()
(gdb) bt
#0  0x00000000 in ?? ()
#1  0x000101b8 in init_rtx_reader_args_cb(int, char**, bool (*)(char const*))
()
#2  0x00008ec4 in main ()

This is a regression from gcc-4.9-20130512 which bootstrapped fine on the same
system.  And build/genconditions was built earlier during stage1 by the system
compiler, and that binary didn't SEGV.