[Bug rtl-optimization/43742] New: web.c/union_match_dups segfaults for a null *ref on sh-elf

["kkojima at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

sh4-unknown-linux-gnu failed to build during compiling libgfortran
with

/exp/ldroot/dodes/xsh-gcc-orig/./gcc/xgcc
-B/exp/ldroot/dodes/xsh-gcc-orig/./gcc/ -B/usr/local/sh4-unknown-linux-gnu/bin/
-B/usr/local/sh4-unknown-linux-gnu/lib/ -isystem
/usr/local/sh4-unknown-linux-gnu/include -isystem
/usr/local/sh4-unknown-linux-gnu/sys-include -DHAVE_CONFIG_H -I.
-I../../../ORIG/trunk/libgfortran -iquote../../../ORIG/trunk/libgfortran/io
-I../../../ORIG/trunk/libgfortran/../gcc
-I../../../ORIG/trunk/libgfortran/../gcc/config -I../.././gcc -D_GNU_SOURCE
-std=gnu99 -Wall -Wstrict-prototypes -Wmissing-prototypes
-Wold-style-definition -Wextra -Wwrite-strings -fcx-fortran-rules
-ffunction-sections -fdata-sections -mieee -ftree-vectorize -funroll-loops -g
-O2 -MT matmul_i1.lo -MD -MP -MF .deps/matmul_i1.Tpo -c
../../../ORIG/trunk/libgfortran/generated/matmul_i1.c  -fPIC -DPIC -o
.libs/matmul_i1.o
../../../ORIG/trunk/libgfortran/generated/matmul_i1.c: In function 'matmul_i1':
../../../ORIG/trunk/libgfortran/generated/matmul_i1.c:374:1: internal compiler
error: Segmentation fault

It starts to fail after

r158187 | bernds | 2010-04-10 21:30:29 +0900 (Sat, 10 Apr 2010) | 7 lines

        * Makefile.in (web.o): Depend on insn-config.h and $(RECOG_H).
        * web.c: Include "insn-config.h" and "recog.h".
        (union_match_dups): New function.
        (web_main): Call it.
        (union_defs): Don't try to recognize match_dups.

and that segfault happens at the line

      (*fun) (use_entry + DF_REF_ID (*dupref), entry + DF_REF_ID (*ref));

of union_match_dups for a null *ref.


-- 
           Summary: web.c/union_match_dups segfaults for a null *ref on sh-
                    elf
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kkojima at gcc dot gnu dot org
GCC target triplet: sh-elf


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43742