expr: remove --bignum and --no-bignum options

* doc/coreutils.texi (expr invocation): Remove the --bignum and
--no-bignum options.  They weren't really needed, and they broke
longstanding (albeit nonportable) scripts.
* src/expr.c: Don't include <assert.h>.  Include "inttostr.h",
"long-options.h", "verify.h".  Check at compile-time that
size_t fits in unsigned long int, as the code assumes this in
several places.
(HAVE_GMP): Define to 0 if not defined, for convenience.
(mpz_t, mpz_clear, mpz_init_set_ui, mpz_init_set_str, mpz_add):
(mpz_sub, mpz_mul, mpz_tdiv_q, mpz_tdiv_r, mpz_get_str, mpz_sgn):
(mpz_fits_ulong_p, mpz_get_ui, mpz_out_str):
Supply substitutes when !HAVE_GMP, which work well enough for
expr's purposes.
(mp_integer): Remove.  All integers are gmp, if gmp is available.
(struct valinfo): Remove 'z' member; no longer needed.  The 'i'
member is always of type mpz_t.
(enum arithmetic_mode, MP_NEVER, MP_ALWAYS, MP_AUTO, mode):
Remove; no longer needed.
(usage): Remove documentation of --bignum and --no-bignum.
(integer_overflow): Abort if error misbehaves, to pacify GCC.
Restore old message on arithmetic overflow, to be conservative.
(die): Omit exit_status parameter; not needed (is always EXPR_FAILURE).
(string_too_long, USE_BIGNUM, NO_USE_BIGNUM, long_options):
Remove; no longer needed.
(main): Don't use getopt_long; this breaks old nonportable scripts.
(int_value): Arg is unsigned, in case we have strings whose length
exceeds LONG_MAX (!).
(int_value, freev, printv, null, tostring, toarith):
(eval6, eval4, eval3):
Always use mpz_ functions, to simplify the code.
(substr_value): Remove; no longer needed.
(getsize): Simplify the API: one arg rather than 3.  Don't assume
unsigned long int fits in size_t.
(promote, domult, dodivide, doadd): Remove; no longer needed.
* tests/misc/expr: Don't use --bignum to test for bignum support.
Instead, use big numbers to test this.

1 files changed, 5 insertions, 15 deletions

diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 183e070bf..64598705d 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -11154,22 +11154,12 @@ may be used for grouping in the usual manner.  You must quote
 parentheses and many operators to avoid the shell evaluating them,
 however.
 
-By default, @command{expr} performs operations using native arithmetic
-types, but if a numeric overflow occurs and @command{expr} was built
-with support for the GNU MP library, @command{expr}, it
-uses arbitrary-precision arithmetic.
+When built with support for the GNU MP library, @command{expr} uses
+arbitrary-precision arithmetic; otherwise, it uses native arithmetic
+types and may fail due to arithmetic overflow.
 
-Apart from @option{--help} and @option{--version} (@pxref{Common
-options}), the following options are supported:
-
-@table @samp
-@item --bignum
-Perform arithmetic operations using unlimited precision via the GNU MP library.
-@item --no-bignum
-Use only limited-precision native operations.
-In the event of numeric overflow, @command{expr} fails,
-even if GNU MP is available.
-@end table
+The only options are @option{--help} and @option{--version}.  @xref{Common
+options}.  Options must precede operands.
 
 @cindex exit status of @command{expr}
 Exit status: