Re: Problem with --version after compiling autoconf

On 05/30/2018 03:24 AM, Andy Armstrong wrote:
> Hi Eric,
> 
> 
> I ran 'make check' and got the following :
> 

> autom4te_perllibdir='..'/lib AUTOM4TE_CFG='../lib/autom4te.cfg'         ../bin/autom4te -B '..'/lib -B '..'/lib --language=autotest -I . -I . suite.at -o ./testsuite.tmp

The command looks reasonable,

> m4:local.at:18: bad expression in eval (bad input): ((?+1+0) > (2+0)) - ((?+1+0) < (2+0))
> autom4te: /workarea/tools/m4/bin/m4 failed with exit status: 1

but things are choking hard at:

m4_version_prereq([2.57])

which expands:

[m4_if(m4_version_compare(]m4_dquote(m4_defn([m4_PACKAGE_VERSION]))[, [$1]),
         [-1],
         [m4_default([$3],
                     [m4_fatal([Autoconf version $1 or higher is required],
                               [63])])],
         [$2])]


which in turn is expanding this macro before calling m4's eval with 
invalid input:

m4_bpatsubst(m4_bpatsubst(m4_translit([[[[0,$1]]]], [.-], [,,]),]dnl
m4_dquote(m4_dquote(m4_defn([m4_cr_Letters])))[[+],
               [+1,-1,[0r36:\&]]), [,0], [,[0r10:0]])

What are the contents of lib/m4sugar/version.m4?  But I suspect that 
part is fine.

Actually, I'm now quite certain that the m4_bpatsubst is not properly 
transliterating EBCDIC values into a base-36 number.  And in fact, 
looking at m4's source code, the problem is in m4 itself:

m4/src/eval.c:eval_lex()


       /* FIXME - this calculation can overflow.  Consider xstrtol.  */
       *val = 0;
       for (; *eval_text; eval_text++)
         {
           if (isdigit (to_uchar (*eval_text)))
             digit = *eval_text - '0';
           else if (islower (to_uchar (*eval_text)))
             digit = *eval_text - 'a' + 10;
           else if (isupper (to_uchar (*eval_text)))
             digit = *eval_text - 'A' + 10;

which means that anything larger than radix 20 (0-9 and a-j) is botched 
on an EBCDIC machine.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
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