From 4fb3704c25726a29b5af658f3137794cdf5cf01c Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Wed, 15 Oct 2008 15:29:38 +0200 Subject: 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 . 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. --- src/expr.c | 713 +++++++++++++++---------------------------------------------- 1 file changed, 176 insertions(+), 537 deletions(-) (limited to 'src') diff --git a/src/expr.c b/src/expr.c index b7bec646b..de7a63de3 100644 --- a/src/expr.c +++ b/src/expr.c @@ -33,16 +33,115 @@ #include #include "system.h" -#include #include -#if HAVE_GMP -#include -#endif #include "error.h" +#include "long-options.h" #include "quotearg.h" #include "strnumcmp.h" #include "xstrtol.h" +/* Various parts of this code assume size_t fits into unsigned long + int, the widest unsigned type that GMP supports. */ +verify (SIZE_MAX <= ULONG_MAX); + +static void integer_overflow (char) ATTRIBUTE_NORETURN; + +#ifndef HAVE_GMP +# define HAVE_GMP 0 +#endif + +#if HAVE_GMP +# include +#else +/* Approximate gmp.h well enough for expr.c's purposes. */ +typedef intmax_t mpz_t[1]; +static void mpz_clear (mpz_t z) {} +static void mpz_init_set_ui (mpz_t z, unsigned long int i) { z[0] = i; } +static int +mpz_init_set_str (mpz_t z, char *s, int base) +{ + return xstrtoimax (s, NULL, base, z, NULL) == LONGINT_OK ? 0 : -1; +} +static void +mpz_add (mpz_t r, mpz_t a0, mpz_t b0) +{ + intmax_t a = a0[0]; + intmax_t b = b0[0]; + intmax_t val = a + b; + if ((val < a) != (b < 0)) + integer_overflow ('+'); + r[0] = val; +} +static void +mpz_sub (mpz_t r, mpz_t a0, mpz_t b0) +{ + intmax_t a = a0[0]; + intmax_t b = b0[0]; + intmax_t val = a - b; + if ((a < val) != (b < 0)) + integer_overflow ('-'); + r[0] = val; +} +static void +mpz_mul (mpz_t r, mpz_t a0, mpz_t b0) +{ + intmax_t a = a0[0]; + intmax_t b = b0[0]; + intmax_t val = a * b; + if (! (a == 0 || b == 0 + || ((val < 0) == ((a < 0) ^ (b < 0)) && val / a == b))) + integer_overflow ('*'); + r[0] = val; +} +static void +mpz_tdiv_q (mpz_t r, mpz_t a0, mpz_t b0) +{ + intmax_t a = a0[0]; + intmax_t b = b0[0]; + + /* Some x86-style hosts raise an exception for INT_MIN / -1. */ + if (a < - INTMAX_MAX && b == -1) + integer_overflow ('/'); + r[0] = a / b; +} +static void +mpz_tdiv_r (mpz_t r, mpz_t a0, mpz_t b0) +{ + intmax_t a = a0[0]; + intmax_t b = b0[0]; + + /* Some x86-style hosts raise an exception for INT_MIN % -1. */ + r[0] = a < - INTMAX_MAX && b == -1 ? 0 : a % b; +} +static char * +mpz_get_str (char const *str, int base, mpz_t z) +{ + char buf[INT_BUFSIZE_BOUND (intmax_t)]; + return xstrdup (imaxtostr (z[0], buf)); +} +static int +mpz_sgn (mpz_t z) +{ + return z[0] < 0 ? -1 : 0 < z[0]; +} +static int +mpz_fits_ulong_p (mpz_t z) +{ + return 0 <= z[0] && z[0] <= ULONG_MAX; +} +static unsigned long int +mpz_get_ui (mpz_t z) +{ + return z[0]; +} +static int +mpz_out_str (FILE *stream, int base, mpz_t z) +{ + char buf[INT_BUFSIZE_BOUND (intmax_t)]; + return fputs (imaxtostr (z[0], buf), stream) != EOF; +} +#endif + /* The official name of this program (e.g., no `g' prefix). */ #define PROGRAM_NAME "expr" @@ -61,14 +160,10 @@ enum EXPR_FAILURE }; -/* The kinds of value we can have. - In the comments below, a variable is described as "arithmetic" if - it is either integer or mp_integer. Variables are of type mp_integer - only if GNU MP is available, but the type designator is always defined. */ +/* The kinds of value we can have. */ enum valtype { integer, - mp_integer, string }; typedef enum valtype TYPE; @@ -79,12 +174,7 @@ struct valinfo TYPE type; /* Which kind. */ union { /* The value itself. */ - /* We could use intmax_t but that would integrate less well with GMP, - since GMP has mpz_set_si but no intmax_t equivalent. */ - signed long int i; -#if HAVE_GMP - mpz_t z; -#endif + mpz_t i; char *s; } u; }; @@ -98,34 +188,6 @@ static bool nomoreargs (void); static bool null (VALUE *v); static void printv (VALUE *v); -/* Arithmetic is done in one of three modes. - - The --bignum option forces all arithmetic to use bignums other than - string indexing (mode==MP_ALWAYS). The --no-bignum option forces - all arithmetic to use native types rather than bignums - (mode==MP_NEVER). - - The default mode is MP_AUTO if GMP is available and MP_NEVER if - not. Most functions will process a bignum if one is found, but - will not convert a native integer to a string if the mode is - MP_NEVER. */ -enum arithmetic_mode - { - MP_NEVER, /* Never use bignums */ -#if HAVE_GMP - MP_ALWAYS, /* Always use bignums. */ - MP_AUTO, /* Switch if result would otherwise overflow */ -#endif - }; -static enum arithmetic_mode mode = -#if HAVE_GMP - MP_AUTO -#else - MP_NEVER -#endif - ; - - void usage (int status) { @@ -140,10 +202,6 @@ Usage: %s EXPRESSION\n\ "), program_name, program_name); putchar ('\n'); - fputs (_("\ - --bignum always use arbitrary-precision arithmetic\n\ - --no-bignum always use single-precision arithmetic\n"), - stdout); fputs (HELP_OPTION_DESCRIPTION, stdout); fputs (VERSION_OPTION_DESCRIPTION, stdout); fputs (_("\ @@ -220,48 +278,23 @@ syntax_error (void) static void integer_overflow (char op) { - error (EXPR_FAILURE, 0, - _("arithmetic operation %c produced an out of range value, " - "but arbitrary-precision arithmetic is not available"), op); + error (EXPR_FAILURE, ERANGE, "%c", op); + abort (); /* notreached */ } -static void die (int exit_status, int errno_val, char const *msg) +static void die (int errno_val, char const *msg) ATTRIBUTE_NORETURN; static void -die (int exit_status, int errno_val, char const *msg) +die (int errno_val, char const *msg) { - assert (exit_status != 0); - error (exit_status, errno_val, "%s", msg); + error (EXPR_FAILURE, errno_val, "%s", msg); abort (); /* notreached */ } -static void -string_too_long (void) -{ - die (EXPR_FAILURE, ERANGE, _("string too long")); -} - -enum -{ - USE_BIGNUM = CHAR_MAX + 1, - NO_USE_BIGNUM -}; - -static struct option const long_options[] = -{ - {"bignum", no_argument, NULL, USE_BIGNUM}, - {"no-bignum", no_argument, NULL, NO_USE_BIGNUM}, - {GETOPT_HELP_OPTION_DECL}, - {GETOPT_VERSION_OPTION_DECL}, - {NULL, 0, NULL, 0} -}; - int main (int argc, char **argv) { VALUE *v; - int c; - int saved_optind; initialize_main (&argc, &argv); set_program_name (argv[0]); @@ -272,51 +305,23 @@ main (int argc, char **argv) initialize_exit_failure (EXPR_FAILURE); atexit (close_stdout); - /* The argument -0 should not result in an error message. */ - opterr = 0; - saved_optind = 1; - - while ((c = getopt_long (argc, argv, "+", long_options, NULL)) != -1) + parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, VERSION, + usage, AUTHORS, (char const *) NULL); + /* The above handles --help and --version. + Since there is no other invocation of getopt, handle `--' here. */ + if (argc > 1 && STREQ (argv[1], "--")) { - /* "expr -0" should interpret the -0 as an integer argument. - arguments like --foo should also be interpreted as a string - argument to be "evaluated". - */ - if ('?' == c) - { - optind = saved_optind; - break; - } - else - switch (c) - { - case USE_BIGNUM: -#if HAVE_GMP - mode = MP_ALWAYS; -#else - error (EXPR_FAILURE, 0, - _("arbitrary-precision support is not available")); -#endif - break; - - case NO_USE_BIGNUM: - mode = MP_NEVER; - break; - - case_GETOPT_HELP_CHAR; - - case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS); - } - saved_optind = optind; + --argc; + ++argv; } - if (argc <= optind) + if (argc <= 1) { error (0, 0, _("missing operand")); usage (EXPR_INVALID); } - args = argv + optind; + args = argv + 1; v = eval (true); if (!nomoreargs ()) @@ -329,21 +334,11 @@ main (int argc, char **argv) /* Return a VALUE for I. */ static VALUE * -int_value (long int i) +int_value (unsigned long int i) { VALUE *v = xmalloc (sizeof *v); -#if HAVE_GMP - if (mode == MP_ALWAYS) - { - /* all integer values are handled as bignums. */ - mpz_init_set_si (v->u.z, i); - v->type = mp_integer; - return v; - } -#endif - v->type = integer; - v->u.i = i; + mpz_init_set_ui (v->u.i, i); return v; } @@ -358,42 +353,15 @@ str_value (char const *s) return v; } - -static VALUE * -substr_value (char const *s, size_t len, size_t pos, size_t nchars_wanted) -{ - if (pos >= len) - return str_value (""); - else - { - VALUE *v = xmalloc (sizeof *v); - size_t vlen = MIN (nchars_wanted, len - pos + 1); - char *vlim; - v->type = string; - v->u.s = xmalloc (vlen + 1); - vlim = mempcpy (v->u.s, s + pos, vlen); - *vlim = '\0'; - return v; - } -} - - /* Free VALUE V, including structure components. */ static void freev (VALUE *v) { if (v->type == string) - { - free (v->u.s); - } - else if (v->type == mp_integer) - { - assert (mode != MP_NEVER); -#if HAVE_GMP - mpz_clear (v->u.z); -#endif - } + free (v->u.s); + else + mpz_clear (v->u.i); free (v); } @@ -405,21 +373,15 @@ printv (VALUE *v) switch (v->type) { case integer: - printf ("%ld\n", v->u.i); + mpz_out_str (stdout, 10, v->u.i); + putchar ('\n'); break; case string: puts (v->u.s); break; -#if HAVE_GMP - case mp_integer: - mpz_out_str (stdout, 10, v->u.z); - putchar ('\n'); - break; -#endif default: abort (); } - } /* Return true if V is a null-string or zero-number. */ @@ -430,11 +392,7 @@ null (VALUE *v) switch (v->type) { case integer: - return v->u.i == 0; -#if HAVE_GMP - case mp_integer: - return mpz_sgn (v->u.z) == 0; -#endif + return mpz_sgn (v->u.i) == 0; case string: { char const *cp = v->u.s; @@ -477,29 +435,16 @@ looks_like_integer (char const *cp) static void tostring (VALUE *v) { - char buf[INT_BUFSIZE_BOUND (long int)]; - switch (v->type) { case integer: - snprintf (buf, sizeof buf, "%ld", v->u.i); - v->u.s = xstrdup (buf); - v->type = string; - break; -#if HAVE_GMP - case mp_integer: { - char *s = mpz_get_str (NULL, 10, v->u.z); - if (!s) - { - xalloc_die (); - } - mpz_clear (v->u.z); + char *s = mpz_get_str (NULL, 10, v->u.i); + mpz_clear (v->u.i); v->u.s = s; v->type = string; } break; -#endif case string: break; default: @@ -507,8 +452,7 @@ tostring (VALUE *v) } } -/* Coerce V to an arithmetic value. - Return true on success, false on failure. */ +/* Coerce V to an integer value. Return true on success, false on failure. */ static bool toarith (VALUE *v) @@ -516,40 +460,17 @@ toarith (VALUE *v) switch (v->type) { case integer: - case mp_integer: return true; - case string: { - long int value; + char *s = v->u.s; - if (! looks_like_integer (v->u.s)) + if (! looks_like_integer (s)) return false; - if (xstrtol (v->u.s, NULL, 10, &value, NULL) != LONGINT_OK) - { -#if HAVE_GMP - if (mode != MP_NEVER) - { - char *s = v->u.s; - if (mpz_init_set_str (v->u.z, s, 10)) - abort (); /* Bug in looks_like_integer, perhaps. */ - v->type = mp_integer; - free (s); - } - else - { - error (EXPR_FAILURE, ERANGE, "%s", v->u.s); - } -#else - error (EXPR_FAILURE, ERANGE, "%s", v->u.s); -#endif - } - else - { - free (v->u.s); - v->u.i = value; - v->type = integer; - } + if (mpz_init_set_str (v->u.i, s, 10) != 0 && !HAVE_GMP) + error (EXPR_FAILURE, ERANGE, "%s", s); + free (s); + v->type = integer; return true; } default: @@ -557,58 +478,23 @@ toarith (VALUE *v) } } -/* Extract a size_t value from a positive arithmetic value, V. - The extracted value is stored in *VAL. */ -static bool -getsize (const VALUE *v, size_t *val, bool *negative) +/* Extract a size_t value from a integer value I. + If the value is negative, return SIZE_MAX. + If the value is too large, return SIZE_MAX - 1. */ +static size_t +getsize (mpz_t i) { - if (v->type == integer) + if (mpz_sgn (i) < 0) + return SIZE_MAX; + if (mpz_fits_ulong_p (i)) { - if (v->u.i < 0) - { - *negative = true; - return false; - } - else - { - *negative = false; - *val = v->u.i; - return true; - } - } - else if (v->type == mp_integer) - { -#if HAVE_GMP - if (mpz_sgn (v->u.z) < 0) - { - *negative = true; - return false; - } - else if (mpz_fits_ulong_p (v->u.z)) - { - unsigned long ul; - ul = mpz_get_ui (v->u.z); - *val = ul; - return true; - } - else - { - *negative = false; - return false; - } -#else - abort (); -#endif - - } - else - { - abort (); /* should not pass a string. */ + unsigned long int ul = mpz_get_ui (i); + if (ul < SIZE_MAX) + return ul; } + return SIZE_MAX - 1; } - - /* Return true and advance if the next token matches STR exactly. STR must not be NULL. */ @@ -787,41 +673,14 @@ eval6 (bool evaluate) } else if (nextarg ("index")) { - size_t pos, len; + size_t pos; l = eval6 (evaluate); r = eval6 (evaluate); tostring (l); tostring (r); pos = strcspn (l->u.s, r->u.s); - len = strlen (l->u.s); - if (pos == len) - { - v = int_value (0); - } - else - { - if (pos < LONG_MAX) - { - v = int_value (pos + 1); - } - else - { -#if HAVE_GMP - if (mode != MP_NEVER - && pos < ULONG_MAX) - { - v = xmalloc (sizeof *v); - mpz_init_set_ui (v->u.z, pos+1); - v->type = mp_integer; - } - else -#endif - { - string_too_long (); - } - } - } + v = int_value (l->u.s[pos] ? pos + 1 : 0); freev (l); freev (r); return v; @@ -839,25 +698,21 @@ eval6 (bool evaluate) v = str_value (""); else { - size_t pos, len; - bool negative = false; - - if (getsize (i1, &pos, &negative)) - if (getsize (i2, &len, &negative)) - if (pos == 0 || len == 0) - v = str_value (""); - else - v = substr_value (l->u.s, llen, pos-1, len); - else - if (negative) - v = str_value (""); - else - die (EXPR_FAILURE, ERANGE, _("string offset is too large")); + size_t pos = getsize (i1->u.i); + size_t len = getsize (i2->u.i); + + if (llen < pos || pos == 0 || len == 0 || len == SIZE_MAX) + v = str_value (""); else - if (negative) - v = str_value (""); - else - die (EXPR_FAILURE, ERANGE, _("substring length too large")); + { + size_t vlen = MIN (len, llen - pos + 1); + char *vlim; + v = xmalloc (sizeof *v); + v->type = string; + v->u.s = xmalloc (vlen + 1); + vlim = mempcpy (v->u.s, l->u.s + pos - 1, vlen); + *vlim = '\0'; + } } freev (l); freev (i1); @@ -900,170 +755,6 @@ eval5 (bool evaluate) } } - -#if HAVE_GMP -static void -promote (VALUE *x) -{ - if (x->type == integer) - mpz_init_set_si (x->u.z, x->u.i); -} -#endif - -/* L = L * R. Both L and R are arithmetic. */ -static void -domult (VALUE *l, VALUE *r) -{ - if (l->type == integer && r->type == integer) - { - long int val = 0; - val = l->u.i * r->u.i; - if (! (l->u.i == 0 || r->u.i == 0 - || ((val < 0) == ((l->u.i < 0) ^ (r->u.i < 0)) - && val / l->u.i == r->u.i))) - { - /* Result would (did) overflow. Handle with MP if available. */ - if (mode != MP_NEVER) - { -#if HAVE_GMP - mpz_init_set_si (l->u.z, l->u.i); - mpz_mul_si (l->u.z, l->u.z, r->u.i); /* L*=R */ - l->type = mp_integer; -#endif - } - else - { - integer_overflow ('*'); - } - } - else - { - l->u.i = val; - } - } - else - { - /* At least one operand is already mp_integer, so promote the other. */ -#if HAVE_GMP - /* We could use mpz_mul_si here if R is not already mp_integer, - but for the moment we'll try to minimise code paths. */ - if (l->type == integer) - mpz_init_set_si (l->u.z, l->u.i); - if (r->type == integer) - mpz_init_set_si (r->u.z, r->u.i); - l->type = r->type = mp_integer; - mpz_mul (l->u.z, l->u.z, r->u.z); /* L*=R */ -#else - abort (); -#endif - } -} - -/* L = L / R or (if WANT_MODULUS) L = L % R */ -static void -dodivide (VALUE *l, VALUE *r, bool want_modulus) -{ - if (r->type == integer && r->u.i == 0) - error (EXPR_INVALID, 0, _("division by zero")); -#if HAVE_GMP - if (r->type == mp_integer && mpz_sgn (r->u.z) == 0) - error (EXPR_INVALID, 0, _("division by zero")); -#endif - if (l->type == integer && r->type == integer) - { - if (l->u.i < - INT_MAX && r->u.i == -1) - { - /* Some x86-style hosts raise an exception for - INT_MIN / -1 and INT_MIN % -1, so handle these - problematic cases specially. */ - if (want_modulus) - { - /* X mod -1 is zero for all negative X. - Although strictly this is implementation-defined, - we don't want to coredump, so we avoid the calculation. */ - l->u.i = 0; - return; - } - else - { - if (mode != MP_NEVER) - { -#if HAVE_GMP - /* Handle the case by promoting. */ - mpz_init_set_si (l->u.z, l->u.i); - l->type = mp_integer; -#endif - } - else - { - integer_overflow ('/'); - } - } - } - else - { - l->u.i = want_modulus ? l->u.i % r->u.i : l->u.i / r->u.i; - return; - } - } - /* If we get to here, at least one operand is mp_integer - and R is not 0. */ -#if HAVE_GMP - { - int sign_l, sign_r; - promote (l); - promote (r); - sign_l = mpz_sgn (l->u.z); - sign_r = mpz_sgn (r->u.z); - - if (!want_modulus) - { - if (!sign_l) - { - mpz_set_si (l->u.z, 0); - } - else if (sign_l < 0 || sign_r < 0) - { - /* At least one operand is negative. For integer arithmetic, - it's platform-dependent if the operation rounds up or down. - We mirror what the implementation does. */ - switch ((3*sign_l) / (2*sign_r)) - { - case 2: /* round toward +inf. */ - case -1: /* round toward +inf. */ - mpz_cdiv_q (l->u.z, l->u.z, r->u.z); - break; - case -2: /* round toward -inf. */ - case 1: /* round toward -inf */ - mpz_fdiv_q (l->u.z, l->u.z, r->u.z); - break; - default: - abort (); - } - } - else - { - /* Both operands positive. Round toward -inf. */ - mpz_fdiv_q (l->u.z, l->u.z, r->u.z); - } - } - else - { - mpz_mod (l->u.z, l->u.z, r->u.z); /* L = L % R */ - - /* If either operand is negative, it's platform-dependent if - the remainer is positive or negative. We mirror what the - implementation does. */ - if (sign_l % sign_r < 0) - mpz_neg (l->u.z, l->u.z); /* L = (-L) */ - } - } -#else - abort (); -#endif -} - - /* Handle *, /, % operators. */ static VALUE * @@ -1092,71 +783,17 @@ eval4 (bool evaluate) { if (!toarith (l) || !toarith (r)) error (EXPR_INVALID, 0, _("non-numeric argument")); - switch (fxn) - { - case multiply: - domult (l, r); - break; - case divide: - case mod: - dodivide (l, r, fxn==mod); - break; - } + if (fxn != multiply && mpz_sgn (r->u.i) == 0) + error (EXPR_INVALID, 0, _("division by zero")); + ((fxn == multiply ? mpz_mul + : fxn == divide ? mpz_tdiv_q + : mpz_tdiv_r) + (l->u.i, l->u.i, r->u.i)); } freev (r); } } -/* L = L + R, or L = L - R */ -static void -doadd (VALUE *l, VALUE *r, bool add) -{ - long int val = 0; - - if (!toarith (l) || !toarith (r)) - error (EXPR_INVALID, 0, _("non-numeric argument")); - if (l->type == integer && r->type == integer) - { - if (add) - { - val = l->u.i + r->u.i; - if ((val < l->u.i) == (r->u.i < 0)) - { - l->u.i = val; - return; - } - } - else - { - val = l->u.i - r->u.i; - if ((l->u.i < val) == (r->u.i < 0)) - { - l->u.i = val; - return; - } - } - } - /* If we get to here, either the operation overflowed or at least - one operand is an mp_integer. */ - if (mode != MP_NEVER) - { -#if HAVE_GMP - promote (l); - promote (r); - if (add) - mpz_add (l->u.z, l->u.z, r->u.z); - else - mpz_sub (l->u.z, l->u.z, r->u.z); -#endif - } - else - { - integer_overflow ('-'); - } -} - - - /* Handle +, - operators. */ static VALUE * @@ -1164,7 +801,7 @@ eval3 (bool evaluate) { VALUE *l; VALUE *r; - bool add; + enum { plus, minus } fxn; #ifdef EVAL_TRACE trace ("eval3"); @@ -1173,15 +810,17 @@ eval3 (bool evaluate) while (1) { if (nextarg ("+")) - add = true; + fxn = plus; else if (nextarg ("-")) - add = false; + fxn = minus; else return l; r = eval4 (evaluate); if (evaluate) { - doadd (l, r, add); + if (!toarith (l) || !toarith (r)) + error (EXPR_INVALID, 0, _("non-numeric argument")); + (fxn == plus ? mpz_add : mpz_sub) (l->u.i, l->u.i, r->u.i); } freev (r); } -- cgit v1.2.3-54-g00ecf