Re: Bison 1.875 coredump

[Paul Govereau]

Thanks for your quick reply. I have tried version 1.875a with the same
results. I have done a little bit of investigation, and it seems like
the problem is parse-gram.y calling into reader.c with an invalid
pointer (loc.start.file). I have attached a stack trace below. Also, I
noticed that if I run bison with "--trace=scan" or "--trace=parse" it
does not crash, and seems to work fine. Once again, my inputs are:

%% A : B %%      --> core dump
%% A : B; %%     --> works fine
%% A : B         --> works fine

Thanks,
Paul Govereau

--- stack trace of core dump ---

pgoverea:/opt/bison-1.875a/dist>gdb ./bin/bison core 
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This GDB was configured as "i386-redhat-linux"...
Core was generated by `./bin/bison parse.y'.
Program terminated with signal 11, Segmentation fault.
Reading symbols from /lib/libc.so.6...done.
Reading symbols from /lib/ld-linux.so.2...done.
#0  0x806168f in quotearg_buffer_restyled (buffer=0x8073a40 "\"", 
    buffersize=256, arg=0x3 <Address 0x3 out of bounds>, argsize=4294967295, 
    quoting_style=c_quoting_style, o=0xbfffc37c) at quotearg.c:256
256       for (i = 0;  ! (argsize == SIZE_MAX ? arg[i] == '\0' : i == argsize); 
 i++)
(gdb) bt
#0  0x806168f in quotearg_buffer_restyled (buffer=0x8073a40 "\"", 
    buffersize=256, arg=0x3 <Address 0x3 out of bounds>, argsize=4294967295, 
    quoting_style=c_quoting_style, o=0xbfffc37c) at quotearg.c:256
#1  0x8061b47 in quotearg_buffer (buffer=0x8073a40 "\"", buffersize=256, 
    arg=0x3 <Address 0x3 out of bounds>, argsize=4294967295, o=0xbfffc37c)
    at quotearg.c:503
#2  0x8061c15 in quotearg_n_options (n=0, arg=0x3 <Address 0x3 out of bounds>, 
    argsize=4294967295, options=0xbfffc37c) at quotearg.c:560
#3  0x8061cfd in quotearg_n_style (n=0, s=c_quoting_style, 
    arg=0x3 <Address 0x3 out of bounds>) at quotearg.c:600
#4  0x8061d48 in quotearg_style (s=c_quoting_style, 
    arg=0x3 <Address 0x3 out of bounds>) at quotearg.c:614
#5  0x80565d8 in epilogue_augment (epilogue=0x807a7d4 "\n", loc={start = {
        file = 0x3 <Address 0x3 out of bounds>, line = 9, column = 134693576}, 
      end = {file = 0x80742c8 "parse.y", line = 5, column = 1}}) at reader.c:93
#6  0x8053fc0 in gram_parse () at parse-gram.y:399
#7  0x805702f in reader () at reader.c:501
#8  0x804d2ea in main (argc=2, argv=0xbffffce4) at main.c:80
(gdb) 

On Apr 01, Paul Eggert wrote:
> Paul Govereau <address@hidden> writes:
> 
> > Bison 1.875 will crash if the last rule does not have a semicolon
> > after it.
> 
> Thanks for your bug report.  I can't reproduce the bug in Bison test
> version 1.875a, which you can get from:
> 
> <ftp://alpha.gnu.org/gnu/bison/bison-1.875a.tar.gz>
> 
> Can you please try that version?  It could be that the bug is
> platform-specific.  Thanks.