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98c52645c

Mike Frysinger
Mike Frysinger
2009-04-02
FAILED Duration: 30s

Subject

split math code out of ash and into a standalone library so we can use it in any shell (like hush!)

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

shell/Config.in +16 -16shell/Kbuild +1 -0shell/ash.c +35 -699shell/hush.c +91 -11shell/math.c +701 -0shell/math.h +101 -0
shell/Config.in+16 -16
@@ -84,22 +84,6 @@ config ASH_ALIAS
help
Enable alias support in the ash shell.
-config ASH_MATH_SUPPORT
- bool "Posix math support"
- default y
- depends on ASH
- help
- Enable math support in the ash shell.
-
-config ASH_MATH_SUPPORT_64
- bool "Extend Posix math support to 64 bit"
- default n
- depends on ASH_MATH_SUPPORT
- help
- Enable 64-bit math support in the ash shell. This will make
- the shell slightly larger, but will allow computation with very
- large numbers.
-
config ASH_GETOPTS
bool "Builtin getopt to parse positional parameters"
default n
@@ -267,6 +251,22 @@ config MSH
comment "Bourne Shell Options"
depends on MSH || LASH || HUSH || ASH
+config SH_MATH_SUPPORT
+ bool "POSIX math support"
+ default y
+ depends on ASH || HUSH
+ help
+ Enable math support in the shell via $((...)) syntax.
+
+config SH_MATH_SUPPORT_64
+ bool "Extend POSIX math support to 64 bit"
+ default n
+ depends on SH_MATH_SUPPORT
+ help
+ Enable 64-bit math support in the shell. This will make the shell
+ slightly larger, but will allow computation with very large numbers.
+ This is not in POSIX, so do not rely on this in portable code.
+
config FEATURE_SH_EXTRA_QUIET
bool "Hide message on interactive shell startup"
default n
shell/Kbuild+1 -0
@@ -9,3 +9,4 @@ lib-$(CONFIG_ASH) += ash.o ash_ptr_hack.o
lib-$(CONFIG_HUSH) += hush.o
lib-$(CONFIG_MSH) += msh.o
lib-$(CONFIG_CTTYHACK) += cttyhack.o
+lib-$(CONFIG_SH_MATH_SUPPORT) += math.o
shell/ash.c+35 -699
@@ -16,19 +16,6 @@
* Original BSD copyright notice is retained at the end of this file.
*/
-/*
- * rewrite arith.y to micro stack based cryptic algorithm by
- * Copyright (c) 2001 Aaron Lehmann <[email protected]>
- *
- * Modified by Paul Mundt <[email protected]> (c) 2004 to support
- * dynamic variables.
- *
- * Modified by Vladimir Oleynik <[email protected]> (c) 2001-2005 to be
- * used in busybox and size optimizations,
- * rewrote arith (see notes to this), added locale support,
- * rewrote dynamic variables.
- */
-
/*
* The following should be set to reflect the type of system you have:
* JOBS -> 1 if you have Berkeley job control, 0 otherwise.
@@ -63,6 +50,7 @@
#include <paths.h>
#include <setjmp.h>
#include <fnmatch.h>
+#include "math.h"
#if defined SINGLE_APPLET_MAIN
/* STANDALONE does not make sense, and won't compile */
@@ -197,6 +185,10 @@ struct globals_misc {
#define debug optlist[15]
#endif
+#if ENABLE_SH_MATH_SUPPORT
+ arith_eval_hooks_t math_hooks;
+#endif
+
/* trap handler commands */
/*
* Sigmode records the current value of the signal handlers for the various
@@ -246,6 +238,7 @@ extern struct globals_misc *const ash_ptr_to_globals_misc;
#define random_LCG (G_misc.random_LCG )
#define backgndpid (G_misc.backgndpid )
#define job_warning (G_misc.job_warning)
+#define math_hooks (G_misc.math_hooks )
#define INIT_G_misc() do { \
(*(struct globals_misc**)&ash_ptr_to_globals_misc) = xzalloc(sizeof(G_misc)); \
barrier(); \
@@ -1998,7 +1991,7 @@ findvar(struct var **vpp, const char *name)
/*
* Find the value of a variable. Returns NULL if not set.
*/
-static char *
+static const char *
lookupvar(const char *name)
{
struct var *v;
@@ -2024,7 +2017,7 @@ lookupvar(const char *name)
/*
* Search the environment of a builtin command.
*/
-static char *
+static const char *
bltinlookup(const char *name)
{
struct strlist *sp;
@@ -2637,7 +2630,7 @@ pwdcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
#define USE_SIT_FUNCTION
#endif
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
static const char S_I_T[][4] = {
#if ENABLE_ASH_ALIAS
{ CSPCL, CIGN, CIGN, CIGN }, /* 0, PEOA */
@@ -2681,7 +2674,7 @@ static const char S_I_T[][3] = {
{ CCTL, CCTL, CCTL } /* 14, CTLESC ... */
#endif
};
-#endif /* ASH_MATH_SUPPORT */
+#endif /* SH_MATH_SUPPORT */
#ifdef USE_SIT_FUNCTION
@@ -4273,7 +4266,7 @@ cmdputs(const char *s)
case CTLBACKQ+CTLQUOTE:
str = "\"$(...)\"";
goto dostr;
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
case CTLARI:
str = "$((";
goto dostr;
@@ -5258,17 +5251,8 @@ redirectsafe(union node *redir, int flags)
* We have to deal with backquotes, shell variables, and file metacharacters.
*/
-#if ENABLE_ASH_MATH_SUPPORT_64
-typedef int64_t arith_t;
-#define arith_t_type long long
-#else
-typedef long arith_t;
-#define arith_t_type long
-#endif
-
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
static arith_t dash_arith(const char *);
-static arith_t arith(const char *expr, int *perrcode);
#endif
/*
@@ -5328,11 +5312,7 @@ cvtnum(arith_t num)
int len;
expdest = makestrspace(32, expdest);
-#if ENABLE_ASH_MATH_SUPPORT_64
- len = fmtstr(expdest, 32, "%lld", (long long) num);
-#else
- len = fmtstr(expdest, 32, "%ld", num);
-#endif
+ len = fmtstr(expdest, 32, arith_t_fmt, num);
STADJUST(len, expdest);
return len;
}
@@ -5696,7 +5676,7 @@ expbackq(union node *cmd, int quoted, int quotes)
stackblock() + startloc));
}
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
/*
* Expand arithmetic expression. Backup to start of expression,
* evaluate, place result in (backed up) result, adjust string position.
@@ -5782,7 +5762,7 @@ argstr(char *p, int flag, struct strlist *var_str_list)
CTLVAR,
CTLBACKQ,
CTLBACKQ | CTLQUOTE,
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
CTLENDARI,
#endif
0
@@ -5819,7 +5799,7 @@ argstr(char *p, int flag, struct strlist *var_str_list)
length += strcspn(p + length, reject);
c = p[length];
if (c && (!(c & 0x80)
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
|| c == CTLENDARI
#endif
)) {
@@ -5897,7 +5877,7 @@ argstr(char *p, int flag, struct strlist *var_str_list)
expbackq(argbackq->n, c, quotes);
argbackq = argbackq->next;
goto start;
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
case CTLENDARI:
p--;
expari(quotes);
@@ -6291,7 +6271,7 @@ static ssize_t
varvalue(char *name, int varflags, int flags, struct strlist *var_str_list)
{
int num;
- char *p;
+ const char *p;
int i;
int sep = 0;
int sepq = 0;
@@ -6324,14 +6304,13 @@ varvalue(char *name, int varflags, int flags, struct strlist *var_str_list)
len = cvtnum(num);
break;
case '-':
- p = makestrspace(NOPTS, expdest);
+ expdest = makestrspace(NOPTS, expdest);
for (i = NOPTS - 1; i >= 0; i--) {
if (optlist[i]) {
- USTPUTC(optletters(i), p);
+ USTPUTC(optletters(i), expdest);
len++;
}
}
- expdest = p;
break;
case '@':
if (sep)
@@ -8710,7 +8689,7 @@ static int getoptscmd(int, char **);
#if !ENABLE_FEATURE_SH_EXTRA_QUIET
static int helpcmd(int, char **);
#endif
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
static int letcmd(int, char **);
#endif
static int readcmd(int, char **);
@@ -8792,7 +8771,7 @@ static const struct builtincmd builtintab[] = {
{ BUILTIN_REGULAR "jobs", jobscmd },
{ BUILTIN_REGULAR "kill", killcmd },
#endif
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
{ BUILTIN_NOSPEC "let", letcmd },
#endif
{ BUILTIN_ASSIGN "local", localcmd },
@@ -10935,7 +10914,7 @@ readtoken1(int firstc, int syntax, char *eofmark, int striptabs)
USTPUTC(c, out);
}
break;
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
case CLP: /* '(' in arithmetic */
parenlevel++;
USTPUTC(c, out);
@@ -10991,7 +10970,7 @@ readtoken1(int firstc, int syntax, char *eofmark, int striptabs)
} /* for (;;) */
}
endword:
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
if (syntax == ARISYNTAX)
raise_error_syntax("missing '))'");
#endif
@@ -11168,7 +11147,7 @@ parsesub: {
pungetc();
} else if (c == '(') { /* $(command) or $((arith)) */
if (pgetc() == '(') {
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
PARSEARITH();
#else
raise_error_syntax("you disabled math support for $((arith)) syntax");
@@ -11423,7 +11402,7 @@ parsebackq: {
goto parsebackq_newreturn;
}
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
/*
* Parse an arithmetic expansion (indicate start of one and set state)
*/
@@ -12384,7 +12363,7 @@ timescmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
return 0;
}
-#if ENABLE_ASH_MATH_SUPPORT
+#if ENABLE_SH_MATH_SUPPORT
static arith_t
dash_arith(const char *s)
{
@@ -12392,7 +12371,7 @@ dash_arith(const char *s)
int errcode = 0;
INT_OFF;
- result = arith(s, &errcode);
+ result = arith(s, &errcode, &math_hooks);
if (errcode < 0) {
if (errcode == -3)
ash_msg_and_raise_error("exponent less than 0");
@@ -12427,7 +12406,7 @@ letcmd(int argc UNUSED_PARAM, char **argv)
return !i;
}
-#endif /* ASH_MATH_SUPPORT */
+#endif /* SH_MATH_SUPPORT */
/* ============ miscbltin.c
@@ -12951,654 +12930,6 @@ ulimitcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
return 0;
}
-
-/* ============ Math support */
-
-#if ENABLE_ASH_MATH_SUPPORT
-
-/* Copyright (c) 2001 Aaron Lehmann <[email protected]>
-
- Permission is hereby granted, free of charge, to any person obtaining
- a copy of this software and associated documentation files (the
- "Software"), to deal in the Software without restriction, including
- without limitation the rights to use, copy, modify, merge, publish,
- distribute, sublicense, and/or sell copies of the Software, and to
- permit persons to whom the Software is furnished to do so, subject to
- the following conditions:
-
- The above copyright notice and this permission notice shall be
- included in all copies or substantial portions of the Software.
-
- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
- IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
- CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
- TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
- SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-*/
-
-/* This is my infix parser/evaluator. It is optimized for size, intended
- * as a replacement for yacc-based parsers. However, it may well be faster
- * than a comparable parser written in yacc. The supported operators are
- * listed in #defines below. Parens, order of operations, and error handling
- * are supported. This code is thread safe. The exact expression format should
- * be that which POSIX specifies for shells. */
-
-/* The code uses a simple two-stack algorithm. See
- * http://www.onthenet.com.au/~grahamis/int2008/week02/lect02.html
- * for a detailed explanation of the infix-to-postfix algorithm on which
- * this is based (this code differs in that it applies operators immediately
- * to the stack instead of adding them to a queue to end up with an
- * expression). */
-
-/* To use the routine, call it with an expression string and error return
- * pointer */
-
-/*
- * Aug 24, 2001 Manuel Novoa III
- *
- * Reduced the generated code size by about 30% (i386) and fixed several bugs.
- *
- * 1) In arith_apply():
- * a) Cached values of *numptr and &(numptr[-1]).
- * b) Removed redundant test for zero denominator.
- *
- * 2) In arith():
- * a) Eliminated redundant code for processing operator tokens by moving
- * to a table-based implementation. Also folded handling of parens
- * into the table.
- * b) Combined all 3 loops which called arith_apply to reduce generated
- * code size at the cost of speed.
- *
- * 3) The following expressions were treated as valid by the original code:
- * 1() , 0! , 1 ( *3 ) .
- * These bugs have been fixed by internally enclosing the expression in
- * parens and then checking that all binary ops and right parens are
- * preceded by a valid expression (NUM_TOKEN).
- *
- * Note: It may be desirable to replace Aaron's test for whitespace with
- * ctype's isspace() if it is used by another busybox applet or if additional
- * whitespace chars should be considered. Look below the "#include"s for a
- * precompiler test.
- */
-
-/*
- * Aug 26, 2001 Manuel Novoa III
- *
- * Return 0 for null expressions. Pointed out by Vladimir Oleynik.
- *
- * Merge in Aaron's comments previously posted to the busybox list,
- * modified slightly to take account of my changes to the code.
- *
- */
-
-/*
- * (C) 2003 Vladimir Oleynik <[email protected]>
- *
- * - allow access to variable,
- * used recursive find value indirection (c=2*2; a="c"; $((a+=2)) produce 6)
- * - realize assign syntax (VAR=expr, +=, *= etc)
- * - realize exponentiation (** operator)
- * - realize comma separated - expr, expr
- * - realise ++expr --expr expr++ expr--
- * - realise expr ? expr : expr (but, second expr calculate always)
- * - allow hexadecimal and octal numbers
- * - was restored loses XOR operator
- * - remove one goto label, added three ;-)
- * - protect $((num num)) as true zero expr (Manuel`s error)
- * - always use special isspace(), see comment from bash ;-)
- */
-
-#define arith_isspace(arithval) \
- (arithval == ' ' || arithval == '\n' || arithval == '\t')
-
-typedef unsigned char operator;
-
-/* An operator's token id is a bit of a bitfield. The lower 5 bits are the
- * precedence, and 3 high bits are an ID unique across operators of that
- * precedence. The ID portion is so that multiple operators can have the
- * same precedence, ensuring that the leftmost one is evaluated first.
- * Consider * and /. */
-
-#define tok_decl(prec,id) (((id)<<5)|(prec))
-#define PREC(op) ((op) & 0x1F)
-
-#define TOK_LPAREN tok_decl(0,0)
-
-#define TOK_COMMA tok_decl(1,0)
-
-#define TOK_ASSIGN tok_decl(2,0)
-#define TOK_AND_ASSIGN tok_decl(2,1)
-#define TOK_OR_ASSIGN tok_decl(2,2)
-#define TOK_XOR_ASSIGN tok_decl(2,3)
-#define TOK_PLUS_ASSIGN tok_decl(2,4)
-#define TOK_MINUS_ASSIGN tok_decl(2,5)
-#define TOK_LSHIFT_ASSIGN tok_decl(2,6)
-#define TOK_RSHIFT_ASSIGN tok_decl(2,7)
-
-#define TOK_MUL_ASSIGN tok_decl(3,0)
-#define TOK_DIV_ASSIGN tok_decl(3,1)
-#define TOK_REM_ASSIGN tok_decl(3,2)
-
-/* all assign is right associativity and precedence eq, but (7+3)<<5 > 256 */
-#define convert_prec_is_assing(prec) do { if (prec == 3) prec = 2; } while (0)
-
-/* conditional is right associativity too */
-#define TOK_CONDITIONAL tok_decl(4,0)
-#define TOK_CONDITIONAL_SEP tok_decl(4,1)
-
-#define TOK_OR tok_decl(5,0)
-
-#define TOK_AND tok_decl(6,0)
-
-#define TOK_BOR tok_decl(7,0)
-
-#define TOK_BXOR tok_decl(8,0)
-
-#define TOK_BAND tok_decl(9,0)
-
-#define TOK_EQ tok_decl(10,0)
-#define TOK_NE tok_decl(10,1)
-
-#define TOK_LT tok_decl(11,0)
-#define TOK_GT tok_decl(11,1)
-#define TOK_GE tok_decl(11,2)
-#define TOK_LE tok_decl(11,3)
-
-#define TOK_LSHIFT tok_decl(12,0)
-#define TOK_RSHIFT tok_decl(12,1)
-
-#define TOK_ADD tok_decl(13,0)
-#define TOK_SUB tok_decl(13,1)
-
-#define TOK_MUL tok_decl(14,0)
-#define TOK_DIV tok_decl(14,1)
-#define TOK_REM tok_decl(14,2)
-
-/* exponent is right associativity */
-#define TOK_EXPONENT tok_decl(15,1)
-
-/* For now unary operators. */
-#define UNARYPREC 16
-#define TOK_BNOT tok_decl(UNARYPREC,0)
-#define TOK_NOT tok_decl(UNARYPREC,1)
-
-#define TOK_UMINUS tok_decl(UNARYPREC+1,0)
-#define TOK_UPLUS tok_decl(UNARYPREC+1,1)
-
-#define PREC_PRE (UNARYPREC+2)
-
-#define TOK_PRE_INC tok_decl(PREC_PRE, 0)
-#define TOK_PRE_DEC tok_decl(PREC_PRE, 1)
-
-#define PREC_POST (UNARYPREC+3)
-
-#define TOK_POST_INC tok_decl(PREC_POST, 0)
-#define TOK_POST_DEC tok_decl(PREC_POST, 1)
-
-#define SPEC_PREC (UNARYPREC+4)
-
-#define TOK_NUM tok_decl(SPEC_PREC, 0)
-#define TOK_RPAREN tok_decl(SPEC_PREC, 1)
-
-#define NUMPTR (*numstackptr)
-
-static int
-tok_have_assign(operator op)
-{
- operator prec = PREC(op);
-
- convert_prec_is_assing(prec);
- return (prec == PREC(TOK_ASSIGN) ||
- prec == PREC_PRE || prec == PREC_POST);
-}
-
-static int
-is_right_associativity(operator prec)
-{
- return (prec == PREC(TOK_ASSIGN) || prec == PREC(TOK_EXPONENT)
- || prec == PREC(TOK_CONDITIONAL));
-}
-
-typedef struct {
- arith_t val;
- arith_t contidional_second_val;
- char contidional_second_val_initialized;
- char *var; /* if NULL then is regular number,
- else is variable name */
-} v_n_t;
-
-typedef struct chk_var_recursive_looped_t {
- const char *var;
- struct chk_var_recursive_looped_t *next;
-} chk_var_recursive_looped_t;
-
-static chk_var_recursive_looped_t *prev_chk_var_recursive;
-
-static int
-arith_lookup_val(v_n_t *t)
-{
- if (t->var) {
- const char * p = lookupvar(t->var);
-
- if (p) {
- int errcode;
-
- /* recursive try as expression */
- chk_var_recursive_looped_t *cur;
- chk_var_recursive_looped_t cur_save;
-
- for (cur = prev_chk_var_recursive; cur; cur = cur->next) {
- if (strcmp(cur->var, t->var) == 0) {
- /* expression recursion loop detected */
- return -5;
- }
- }
- /* save current lookuped var name */
- cur = prev_chk_var_recursive;
- cur_save.var = t->var;
- cur_save.next = cur;
- prev_chk_var_recursive = &cur_save;
-
- t->val = arith (p, &errcode);
- /* restore previous ptr after recursiving */
- prev_chk_var_recursive = cur;
- return errcode;
- }
- /* allow undefined var as 0 */
- t->val = 0;
- }
- return 0;
-}
-
-/* "applying" a token means performing it on the top elements on the integer
- * stack. For a unary operator it will only change the top element, but a
- * binary operator will pop two arguments and push a result */
-static int
-arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr)
-{
- v_n_t *numptr_m1;
- arith_t numptr_val, rez;
- int ret_arith_lookup_val;
-
- /* There is no operator that can work without arguments */
- if (NUMPTR == numstack) goto err;
- numptr_m1 = NUMPTR - 1;
-
- /* check operand is var with noninteger value */
- ret_arith_lookup_val = arith_lookup_val(numptr_m1);
- if (ret_arith_lookup_val)
- return ret_arith_lookup_val;
-
- rez = numptr_m1->val;
- if (op == TOK_UMINUS)
- rez *= -1;
- else if (op == TOK_NOT)
- rez = !rez;
- else if (op == TOK_BNOT)
- rez = ~rez;
- else if (op == TOK_POST_INC || op == TOK_PRE_INC)
- rez++;
- else if (op == TOK_POST_DEC || op == TOK_PRE_DEC)
- rez--;
- else if (op != TOK_UPLUS) {
- /* Binary operators */
-
- /* check and binary operators need two arguments */
- if (numptr_m1 == numstack) goto err;
-
- /* ... and they pop one */
- --NUMPTR;
- numptr_val = rez;
- if (op == TOK_CONDITIONAL) {
- if (!numptr_m1->contidional_second_val_initialized) {
- /* protect $((expr1 ? expr2)) without ": expr" */
- goto err;
- }
- rez = numptr_m1->contidional_second_val;
- } else if (numptr_m1->contidional_second_val_initialized) {
- /* protect $((expr1 : expr2)) without "expr ? " */
- goto err;
- }
- numptr_m1 = NUMPTR - 1;
- if (op != TOK_ASSIGN) {
- /* check operand is var with noninteger value for not '=' */
- ret_arith_lookup_val = arith_lookup_val(numptr_m1);
- if (ret_arith_lookup_val)
- return ret_arith_lookup_val;
- }
- if (op == TOK_CONDITIONAL) {
- numptr_m1->contidional_second_val = rez;
- }
- rez = numptr_m1->val;
- if (op == TOK_BOR || op == TOK_OR_ASSIGN)
- rez |= numptr_val;
- else if (op == TOK_OR)
- rez = numptr_val || rez;
- else if (op == TOK_BAND || op == TOK_AND_ASSIGN)
- rez &= numptr_val;
- else if (op == TOK_BXOR || op == TOK_XOR_ASSIGN)
- rez ^= numptr_val;
- else if (op == TOK_AND)
- rez = rez && numptr_val;
- else if (op == TOK_EQ)
- rez = (rez == numptr_val);
- else if (op == TOK_NE)
- rez = (rez != numptr_val);
- else if (op == TOK_GE)
- rez = (rez >= numptr_val);
- else if (op == TOK_RSHIFT || op == TOK_RSHIFT_ASSIGN)
- rez >>= numptr_val;
- else if (op == TOK_LSHIFT || op == TOK_LSHIFT_ASSIGN)
- rez <<= numptr_val;
- else if (op == TOK_GT)
- rez = (rez > numptr_val);
- else if (op == TOK_LT)
- rez = (rez < numptr_val);
- else if (op == TOK_LE)
- rez = (rez <= numptr_val);
- else if (op == TOK_MUL || op == TOK_MUL_ASSIGN)
- rez *= numptr_val;
- else if (op == TOK_ADD || op == TOK_PLUS_ASSIGN)
- rez += numptr_val;
- else if (op == TOK_SUB || op == TOK_MINUS_ASSIGN)
- rez -= numptr_val;
- else if (op == TOK_ASSIGN || op == TOK_COMMA)
- rez = numptr_val;
- else if (op == TOK_CONDITIONAL_SEP) {
- if (numptr_m1 == numstack) {
- /* protect $((expr : expr)) without "expr ? " */
- goto err;
- }
- numptr_m1->contidional_second_val_initialized = op;
- numptr_m1->contidional_second_val = numptr_val;
- } else if (op == TOK_CONDITIONAL) {
- rez = rez ?
- numptr_val : numptr_m1->contidional_second_val;
- } else if (op == TOK_EXPONENT) {
- if (numptr_val < 0)
- return -3; /* exponent less than 0 */
- else {
- arith_t c = 1;
-
- if (numptr_val)
- while (numptr_val--)
- c *= rez;
- rez = c;
- }
- } else if (numptr_val==0) /* zero divisor check */
- return -2;
- else if (op == TOK_DIV || op == TOK_DIV_ASSIGN)
- rez /= numptr_val;
- else if (op == TOK_REM || op == TOK_REM_ASSIGN)
- rez %= numptr_val;
- }
- if (tok_have_assign(op)) {
- char buf[sizeof(arith_t_type)*3 + 2];
-
- if (numptr_m1->var == NULL) {
- /* Hmm, 1=2 ? */
- goto err;
- }
- /* save to shell variable */
-#if ENABLE_ASH_MATH_SUPPORT_64
- snprintf(buf, sizeof(buf), "%lld", (arith_t_type) rez);
-#else
- snprintf(buf, sizeof(buf), "%ld", (arith_t_type) rez);
-#endif
- setvar(numptr_m1->var, buf, 0);
- /* after saving, make previous value for v++ or v-- */
- if (op == TOK_POST_INC)
- rez--;
- else if (op == TOK_POST_DEC)
- rez++;
- }
- numptr_m1->val = rez;
- /* protect geting var value, is number now */
- numptr_m1->var = NULL;
- return 0;
- err:
- return -1;
-}
-
-/* longest must be first */
-static const char op_tokens[] ALIGN1 = {
- '<','<','=',0, TOK_LSHIFT_ASSIGN,
- '>','>','=',0, TOK_RSHIFT_ASSIGN,
- '<','<', 0, TOK_LSHIFT,
- '>','>', 0, TOK_RSHIFT,
- '|','|', 0, TOK_OR,
- '&','&', 0, TOK_AND,
- '!','=', 0, TOK_NE,
- '<','=', 0, TOK_LE,
- '>','=', 0, TOK_GE,
- '=','=', 0, TOK_EQ,
- '|','=', 0, TOK_OR_ASSIGN,
- '&','=', 0, TOK_AND_ASSIGN,
- '*','=', 0, TOK_MUL_ASSIGN,
- '/','=', 0, TOK_DIV_ASSIGN,
- '%','=', 0, TOK_REM_ASSIGN,
- '+','=', 0, TOK_PLUS_ASSIGN,
- '-','=', 0, TOK_MINUS_ASSIGN,
- '-','-', 0, TOK_POST_DEC,
- '^','=', 0, TOK_XOR_ASSIGN,
- '+','+', 0, TOK_POST_INC,
- '*','*', 0, TOK_EXPONENT,
- '!', 0, TOK_NOT,
- '<', 0, TOK_LT,
- '>', 0, TOK_GT,
- '=', 0, TOK_ASSIGN,
- '|', 0, TOK_BOR,
- '&', 0, TOK_BAND,
- '*', 0, TOK_MUL,
- '/', 0, TOK_DIV,
- '%', 0, TOK_REM,
- '+', 0, TOK_ADD,
- '-', 0, TOK_SUB,
- '^', 0, TOK_BXOR,
- /* uniq */
- '~', 0, TOK_BNOT,
- ',', 0, TOK_COMMA,
- '?', 0, TOK_CONDITIONAL,
- ':', 0, TOK_CONDITIONAL_SEP,
- ')', 0, TOK_RPAREN,
- '(', 0, TOK_LPAREN,
- 0
-};
-/* ptr to ")" */
-#define endexpression (&op_tokens[sizeof(op_tokens)-7])
-
-static arith_t
-arith(const char *expr, int *perrcode)
-{
- char arithval; /* Current character under analysis */
- operator lasttok, op;
- operator prec;
- operator *stack, *stackptr;
- const char *p = endexpression;
- int errcode;
- v_n_t *numstack, *numstackptr;
- unsigned datasizes = strlen(expr) + 2;
-
- /* Stack of integers */
- /* The proof that there can be no more than strlen(startbuf)/2+1 integers
- * in any given correct or incorrect expression is left as an exercise to
- * the reader. */
- numstackptr = numstack = alloca((datasizes / 2) * sizeof(numstack[0]));
- /* Stack of operator tokens */
- stackptr = stack = alloca(datasizes * sizeof(stack[0]));
-
- *stackptr++ = lasttok = TOK_LPAREN; /* start off with a left paren */
- *perrcode = errcode = 0;
-
- while (1) {
- arithval = *expr;
- if (arithval == 0) {
- if (p == endexpression) {
- /* Null expression. */
- return 0;
- }
-
- /* This is only reached after all tokens have been extracted from the
- * input stream. If there are still tokens on the operator stack, they
- * are to be applied in order. At the end, there should be a final
- * result on the integer stack */
-
- if (expr != endexpression + 1) {
- /* If we haven't done so already, */
- /* append a closing right paren */
- expr = endexpression;
- /* and let the loop process it. */
- continue;
- }
- /* At this point, we're done with the expression. */
- if (numstackptr != numstack+1) {
- /* ... but if there isn't, it's bad */
- err:
- *perrcode = -1;
- return *perrcode;
- }
- if (numstack->var) {
- /* expression is $((var)) only, lookup now */
- errcode = arith_lookup_val(numstack);
- }
- ret:
- *perrcode = errcode;
- return numstack->val;
- }
-
- /* Continue processing the expression. */
- if (arith_isspace(arithval)) {
- /* Skip whitespace */
- goto prologue;
- }
- p = endofname(expr);
- if (p != expr) {
- size_t var_name_size = (p-expr) + 1; /* trailing zero */
-
- numstackptr->var = alloca(var_name_size);
- safe_strncpy(numstackptr->var, expr, var_name_size);
- expr = p;
- num:
- numstackptr->contidional_second_val_initialized = 0;
- numstackptr++;
- lasttok = TOK_NUM;
- continue;
- }
- if (isdigit(arithval)) {
- numstackptr->var = NULL;
-#if ENABLE_ASH_MATH_SUPPORT_64
- numstackptr->val = strtoll(expr, (char **) &expr, 0);
-#else
- numstackptr->val = strtol(expr, (char **) &expr, 0);
-#endif
- goto num;
- }
- for (p = op_tokens; ; p++) {
- const char *o;
-
- if (*p == 0) {
- /* strange operator not found */
- goto err;
- }
- for (o = expr; *p && *o == *p; p++)
- o++;
- if (!*p) {
- /* found */
- expr = o - 1;
- break;
- }
- /* skip tail uncompared token */
- while (*p)
- p++;
- /* skip zero delim */
- p++;
- }
- op = p[1];
-
- /* post grammar: a++ reduce to num */
- if (lasttok == TOK_POST_INC || lasttok == TOK_POST_DEC)
- lasttok = TOK_NUM;
-
- /* Plus and minus are binary (not unary) _only_ if the last
- * token was as number, or a right paren (which pretends to be
- * a number, since it evaluates to one). Think about it.
- * It makes sense. */
- if (lasttok != TOK_NUM) {
- switch (op) {
- case TOK_ADD:
- op = TOK_UPLUS;
- break;
- case TOK_SUB:
- op = TOK_UMINUS;
- break;
- case TOK_POST_INC:
- op = TOK_PRE_INC;
- break;
- case TOK_POST_DEC:
- op = TOK_PRE_DEC;
- break;
- }
- }
- /* We don't want a unary operator to cause recursive descent on the
- * stack, because there can be many in a row and it could cause an
- * operator to be evaluated before its argument is pushed onto the
- * integer stack. */
- /* But for binary operators, "apply" everything on the operator
- * stack until we find an operator with a lesser priority than the
- * one we have just extracted. */
- /* Left paren is given the lowest priority so it will never be
- * "applied" in this way.
- * if associativity is right and priority eq, applied also skip
- */
- prec = PREC(op);
- if ((prec > 0 && prec < UNARYPREC) || prec == SPEC_PREC) {
- /* not left paren or unary */
- if (lasttok != TOK_NUM) {
- /* binary op must be preceded by a num */
- goto err;
- }
- while (stackptr != stack) {
- if (op == TOK_RPAREN) {
- /* The algorithm employed here is simple: while we don't
- * hit an open paren nor the bottom of the stack, pop
- * tokens and apply them */
- if (stackptr[-1] == TOK_LPAREN) {
- --stackptr;
- /* Any operator directly after a */
- lasttok = TOK_NUM;
- /* close paren should consider itself binary */
- goto prologue;
- }
- } else {
- operator prev_prec = PREC(stackptr[-1]);
-
- convert_prec_is_assing(prec);
- convert_prec_is_assing(prev_prec);
- if (prev_prec < prec)
- break;
- /* check right assoc */
- if (prev_prec == prec && is_right_associativity(prec))
- break;
- }
- errcode = arith_apply(*--stackptr, numstack, &numstackptr);
- if (errcode) goto ret;
- }
- if (op == TOK_RPAREN) {
- goto err;
- }
- }
-
- /* Push this operator to the stack and remember it. */
- *stackptr++ = lasttok = op;
- prologue:
- ++expr;
- } /* while */
-}
-#endif /* ASH_MATH_SUPPORT */
-
-
/* ============ main() and helpers */
/*
@@ -13786,7 +13117,7 @@ extern int etext();
int ash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ash_main(int argc UNUSED_PARAM, char **argv)
{
- char *shinit;
+ const char *shinit;
volatile smallint state;
struct jmploc jmploc;
struct stackmark smark;
@@ -13799,6 +13130,11 @@ int ash_main(int argc UNUSED_PARAM, char **argv)
INIT_G_alias();
#endif
INIT_G_cmdtable();
+#if ENABLE_SH_MATH_SUPPORT
+ math_hooks.lookupvar = lookupvar;
+ math_hooks.setvar = setvar;
+ math_hooks.endofname = endofname;
+#endif
#if PROFILE
monitor(4, etext, profile_buf, sizeof(profile_buf), 50);
shell/hush.c+91 -11
@@ -76,6 +76,8 @@
#include <fnmatch.h>
#endif
+#include "math.h"
+
#define HUSH_VER_STR "0.92"
#if defined SINGLE_APPLET_MAIN
@@ -451,6 +453,9 @@ struct globals {
#endif
#if ENABLE_FEATURE_EDITING
line_input_t *line_input_state;
+#endif
+#if ENABLE_SH_MATH_SUPPORT
+ arith_eval_hooks_t hooks;
#endif
pid_t root_pid;
pid_t last_bg_pid;
@@ -1164,6 +1169,31 @@ static int unset_local_var(const char *name)
return EXIT_SUCCESS;
}
+#if ENABLE_SH_MATH_SUPPORT
+#define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
+#define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
+static char *endofname(const char *name)
+{
+ char *p;
+
+ p = (char *) name;
+ if (!is_name(*p))
+ return p;
+ while (*++p) {
+ if (!is_in_name(*p))
+ break;
+ }
+ return p;
+}
+
+static void arith_set_local_var(const char *name, const char *val, int flags)
+{
+ /* arith code doesnt malloc space, so do it for it */
+ char *var = xmalloc(strlen(name) + 1 + strlen(val) + 1);
+ sprintf(var, "%s=%s", name, val);
+ set_local_var(var, flags);
+}
+#endif
/*
* in_str support
@@ -1374,6 +1404,11 @@ static void o_addstr(o_string *o, const char *str, int len)
o->data[o->length] = '\0';
}
+static void o_addstrauto(o_string *o, const char *str)
+{
+ o_addstr(o, str, strlen(str) + 1);
+}
+
static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len)
{
while (len) {
@@ -1564,7 +1599,7 @@ static int o_glob(o_string *o, int n)
char **argv = globdata.gl_pathv;
o->length = pattern - o->data; /* "forget" pattern */
while (1) {
- o_addstr(o, *argv, strlen(*argv) + 1);
+ o_addstrauto(o, *argv);
n = o_save_ptr_helper(o, n);
argv++;
if (!*argv)
@@ -1769,6 +1804,28 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
val = subst_result.data;
goto store_val;
}
+#endif
+#if ENABLE_SH_MATH_SUPPORT
+ case '+': { /* <SPECIAL_VAR_SYMBOL>(cmd<SPECIAL_VAR_SYMBOL> */
+ arith_t res;
+ char buf[30];
+ int errcode;
+ *p = '\0';
+ ++arg;
+ debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
+ res = arith(arg, &errcode, &G.hooks);
+ if (errcode < 0)
+ switch (errcode) {
+ case -3: maybe_die("arith", "exponent less than 0"); break;
+ case -2: maybe_die("arith", "divide by zero"); break;
+ case -5: maybe_die("arith", "expression recursion loop detected"); break;
+ default: maybe_die("arith", "syntax error");
+ }
+ sprintf(buf, arith_t_fmt, res);
+ o_addstrauto(output, buf);
+ debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
+ break;
+ }
#endif
default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
case_default: {
@@ -1877,7 +1934,7 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
debug_print_list("expand_vars_to_list[a]", output, n);
/* this part is literal, and it was already pre-quoted
* if needed (much earlier), do not use o_addQstr here! */
- o_addstr(output, arg, strlen(arg) + 1);
+ o_addstrauto(output, arg);
debug_print_list("expand_vars_to_list[b]", output, n);
} else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
&& !(ored_ch & 0x80) /* and all vars were not quoted. */
@@ -3754,7 +3811,7 @@ static int parse_group(o_string *dest, struct parse_context *ctx,
/* command remains "open", available for possible redirects */
}
-#if ENABLE_HUSH_TICK
+#if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
/* Subroutines for copying $(...) and `...` things */
static void add_till_backquote(o_string *dest, struct in_str *input);
/* '...' */
@@ -3834,7 +3891,7 @@ static void add_till_backquote(o_string *dest, struct in_str *input)
* echo $(echo 'TEST)' BEST) TEST) BEST
* echo $(echo \(\(TEST\) BEST) ((TEST) BEST
*/
-static void add_till_closing_curly_brace(o_string *dest, struct in_str *input)
+static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
{
int count = 0;
while (1) {
@@ -3844,8 +3901,14 @@ static void add_till_closing_curly_brace(o_string *dest, struct in_str *input)
if (ch == '(')
count++;
if (ch == ')')
- if (--count < 0)
- break;
+ if (--count < 0) {
+ if (!dbl)
+ break;
+ if (i_peek(input) == ')') {
+ i_getch(input);
+ break;
+ }
+ }
o_addchr(dest, ch);
if (ch == '\'') {
add_till_single_quote(dest, input);
@@ -3866,7 +3929,7 @@ static void add_till_closing_curly_brace(o_string *dest, struct in_str *input)
}
}
}
-#endif /* ENABLE_HUSH_TICK */
+#endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
/* Return code: 0 for OK, 1 for syntax error */
static int handle_dollar(o_string *dest, struct in_str *input)
@@ -3983,18 +4046,30 @@ static int handle_dollar(o_string *dest, struct in_str *input)
o_addchr(dest, SPECIAL_VAR_SYMBOL);
break;
}
-#if ENABLE_HUSH_TICK
case '(': {
- //int pos = dest->length;
i_getch(input);
+
+#if ENABLE_SH_MATH_SUPPORT
+ if (i_peek(input) == '(') {
+ i_getch(input);
+ o_addchr(dest, SPECIAL_VAR_SYMBOL);
+ o_addchr(dest, quote_mask | '+');
+ add_till_closing_paren(dest, input, true);
+ o_addchr(dest, SPECIAL_VAR_SYMBOL);
+ break;
+ }
+#endif
+
+#if ENABLE_HUSH_TICK
+ //int pos = dest->length;
o_addchr(dest, SPECIAL_VAR_SYMBOL);
o_addchr(dest, quote_mask | '`');
- add_till_closing_curly_brace(dest, input);
+ add_till_closing_paren(dest, input, false);
//debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
o_addchr(dest, SPECIAL_VAR_SYMBOL);
+#endif
break;
}
-#endif
case '_':
i_getch(input);
ch = i_peek(input);
@@ -4525,6 +4600,11 @@ int hush_main(int argc, char **argv)
#if ENABLE_FEATURE_EDITING
G.line_input_state = new_line_input_t(FOR_SHELL);
+#endif
+#if ENABLE_SH_MATH_SUPPORT
+ G.hooks.lookupvar = lookup_param;
+ G.hooks.setvar = arith_set_local_var;
+ G.hooks.endofname = endofname;
#endif
/* XXX what should these be while sourcing /etc/profile? */
G.global_argc = argc;
shell/math.c+701 -0
@@ -0,0 +1,701 @@
+/*
+ * arithmetic code ripped out of ash shell for code sharing
+ *
+ * Copyright (c) 1989, 1991, 1993, 1994
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Copyright (c) 1997-2005 Herbert Xu <[email protected]>
+ * was re-ported from NetBSD and debianized.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ *
+ * Original BSD copyright notice is retained at the end of this file.
+ */
+/*
+ * rewrite arith.y to micro stack based cryptic algorithm by
+ * Copyright (c) 2001 Aaron Lehmann <[email protected]>
+ *
+ * Modified by Paul Mundt <[email protected]> (c) 2004 to support
+ * dynamic variables.
+ *
+ * Modified by Vladimir Oleynik <[email protected]> (c) 2001-2005 to be
+ * used in busybox and size optimizations,
+ * rewrote arith (see notes to this), added locale support,
+ * rewrote dynamic variables.
+ */
+
+#include "busybox.h"
+#include "math.h"
+
+#define a_e_h_t arith_eval_hooks_t
+#define lookupvar (math_hooks->lookupvar)
+#define setvar (math_hooks->setvar)
+#define endofname (math_hooks->endofname)
+
+/* Copyright (c) 2001 Aaron Lehmann <[email protected]>
+
+ Permission is hereby granted, free of charge, to any person obtaining
+ a copy of this software and associated documentation files (the
+ "Software"), to deal in the Software without restriction, including
+ without limitation the rights to use, copy, modify, merge, publish,
+ distribute, sublicense, and/or sell copies of the Software, and to
+ permit persons to whom the Software is furnished to do so, subject to
+ the following conditions:
+
+ The above copyright notice and this permission notice shall be
+ included in all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+/* This is my infix parser/evaluator. It is optimized for size, intended
+ * as a replacement for yacc-based parsers. However, it may well be faster
+ * than a comparable parser written in yacc. The supported operators are
+ * listed in #defines below. Parens, order of operations, and error handling
+ * are supported. This code is thread safe. The exact expression format should
+ * be that which POSIX specifies for shells. */
+
+/* The code uses a simple two-stack algorithm. See
+ * http://www.onthenet.com.au/~grahamis/int2008/week02/lect02.html
+ * for a detailed explanation of the infix-to-postfix algorithm on which
+ * this is based (this code differs in that it applies operators immediately
+ * to the stack instead of adding them to a queue to end up with an
+ * expression). */
+
+/* To use the routine, call it with an expression string and error return
+ * pointer */
+
+/*
+ * Aug 24, 2001 Manuel Novoa III
+ *
+ * Reduced the generated code size by about 30% (i386) and fixed several bugs.
+ *
+ * 1) In arith_apply():
+ * a) Cached values of *numptr and &(numptr[-1]).
+ * b) Removed redundant test for zero denominator.
+ *
+ * 2) In arith():
+ * a) Eliminated redundant code for processing operator tokens by moving
+ * to a table-based implementation. Also folded handling of parens
+ * into the table.
+ * b) Combined all 3 loops which called arith_apply to reduce generated
+ * code size at the cost of speed.
+ *
+ * 3) The following expressions were treated as valid by the original code:
+ * 1() , 0! , 1 ( *3 ) .
+ * These bugs have been fixed by internally enclosing the expression in
+ * parens and then checking that all binary ops and right parens are
+ * preceded by a valid expression (NUM_TOKEN).
+ *
+ * Note: It may be desirable to replace Aaron's test for whitespace with
+ * ctype's isspace() if it is used by another busybox applet or if additional
+ * whitespace chars should be considered. Look below the "#include"s for a
+ * precompiler test.
+ */
+
+/*
+ * Aug 26, 2001 Manuel Novoa III
+ *
+ * Return 0 for null expressions. Pointed out by Vladimir Oleynik.
+ *
+ * Merge in Aaron's comments previously posted to the busybox list,
+ * modified slightly to take account of my changes to the code.
+ *
+ */
+
+/*
+ * (C) 2003 Vladimir Oleynik <[email protected]>
+ *
+ * - allow access to variable,
+ * used recursive find value indirection (c=2*2; a="c"; $((a+=2)) produce 6)
+ * - realize assign syntax (VAR=expr, +=, *= etc)
+ * - realize exponentiation (** operator)
+ * - realize comma separated - expr, expr
+ * - realise ++expr --expr expr++ expr--
+ * - realise expr ? expr : expr (but, second expr calculate always)
+ * - allow hexadecimal and octal numbers
+ * - was restored loses XOR operator
+ * - remove one goto label, added three ;-)
+ * - protect $((num num)) as true zero expr (Manuel`s error)
+ * - always use special isspace(), see comment from bash ;-)
+ */
+
+#define arith_isspace(arithval) \
+ (arithval == ' ' || arithval == '\n' || arithval == '\t')
+
+typedef unsigned char operator;
+
+/* An operator's token id is a bit of a bitfield. The lower 5 bits are the
+ * precedence, and 3 high bits are an ID unique across operators of that
+ * precedence. The ID portion is so that multiple operators can have the
+ * same precedence, ensuring that the leftmost one is evaluated first.
+ * Consider * and /. */
+
+#define tok_decl(prec,id) (((id)<<5)|(prec))
+#define PREC(op) ((op) & 0x1F)
+
+#define TOK_LPAREN tok_decl(0,0)
+
+#define TOK_COMMA tok_decl(1,0)
+
+#define TOK_ASSIGN tok_decl(2,0)
+#define TOK_AND_ASSIGN tok_decl(2,1)
+#define TOK_OR_ASSIGN tok_decl(2,2)
+#define TOK_XOR_ASSIGN tok_decl(2,3)
+#define TOK_PLUS_ASSIGN tok_decl(2,4)
+#define TOK_MINUS_ASSIGN tok_decl(2,5)
+#define TOK_LSHIFT_ASSIGN tok_decl(2,6)
+#define TOK_RSHIFT_ASSIGN tok_decl(2,7)
+
+#define TOK_MUL_ASSIGN tok_decl(3,0)
+#define TOK_DIV_ASSIGN tok_decl(3,1)
+#define TOK_REM_ASSIGN tok_decl(3,2)
+
+/* all assign is right associativity and precedence eq, but (7+3)<<5 > 256 */
+#define convert_prec_is_assing(prec) do { if (prec == 3) prec = 2; } while (0)
+
+/* conditional is right associativity too */
+#define TOK_CONDITIONAL tok_decl(4,0)
+#define TOK_CONDITIONAL_SEP tok_decl(4,1)
+
+#define TOK_OR tok_decl(5,0)
+
+#define TOK_AND tok_decl(6,0)
+
+#define TOK_BOR tok_decl(7,0)
+
+#define TOK_BXOR tok_decl(8,0)
+
+#define TOK_BAND tok_decl(9,0)
+
+#define TOK_EQ tok_decl(10,0)
+#define TOK_NE tok_decl(10,1)
+
+#define TOK_LT tok_decl(11,0)
+#define TOK_GT tok_decl(11,1)
+#define TOK_GE tok_decl(11,2)
+#define TOK_LE tok_decl(11,3)
+
+#define TOK_LSHIFT tok_decl(12,0)
+#define TOK_RSHIFT tok_decl(12,1)
+
+#define TOK_ADD tok_decl(13,0)
+#define TOK_SUB tok_decl(13,1)
+
+#define TOK_MUL tok_decl(14,0)
+#define TOK_DIV tok_decl(14,1)
+#define TOK_REM tok_decl(14,2)
+
+/* exponent is right associativity */
+#define TOK_EXPONENT tok_decl(15,1)
+
+/* For now unary operators. */
+#define UNARYPREC 16
+#define TOK_BNOT tok_decl(UNARYPREC,0)
+#define TOK_NOT tok_decl(UNARYPREC,1)
+
+#define TOK_UMINUS tok_decl(UNARYPREC+1,0)
+#define TOK_UPLUS tok_decl(UNARYPREC+1,1)
+
+#define PREC_PRE (UNARYPREC+2)
+
+#define TOK_PRE_INC tok_decl(PREC_PRE, 0)
+#define TOK_PRE_DEC tok_decl(PREC_PRE, 1)
+
+#define PREC_POST (UNARYPREC+3)
+
+#define TOK_POST_INC tok_decl(PREC_POST, 0)
+#define TOK_POST_DEC tok_decl(PREC_POST, 1)
+
+#define SPEC_PREC (UNARYPREC+4)
+
+#define TOK_NUM tok_decl(SPEC_PREC, 0)
+#define TOK_RPAREN tok_decl(SPEC_PREC, 1)
+
+#define NUMPTR (*numstackptr)
+
+static int
+tok_have_assign(operator op)
+{
+ operator prec = PREC(op);
+
+ convert_prec_is_assing(prec);
+ return (prec == PREC(TOK_ASSIGN) ||
+ prec == PREC_PRE || prec == PREC_POST);
+}
+
+static int
+is_right_associativity(operator prec)
+{
+ return (prec == PREC(TOK_ASSIGN) || prec == PREC(TOK_EXPONENT)
+ || prec == PREC(TOK_CONDITIONAL));
+}
+
+typedef struct {
+ arith_t val;
+ arith_t contidional_second_val;
+ char contidional_second_val_initialized;
+ char *var; /* if NULL then is regular number,
+ else is variable name */
+} v_n_t;
+
+typedef struct chk_var_recursive_looped_t {
+ const char *var;
+ struct chk_var_recursive_looped_t *next;
+} chk_var_recursive_looped_t;
+
+static chk_var_recursive_looped_t *prev_chk_var_recursive;
+
+static int
+arith_lookup_val(v_n_t *t, a_e_h_t *math_hooks)
+{
+ if (t->var) {
+ const char * p = lookupvar(t->var);
+
+ if (p) {
+ int errcode;
+
+ /* recursive try as expression */
+ chk_var_recursive_looped_t *cur;
+ chk_var_recursive_looped_t cur_save;
+
+ for (cur = prev_chk_var_recursive; cur; cur = cur->next) {
+ if (strcmp(cur->var, t->var) == 0) {
+ /* expression recursion loop detected */
+ return -5;
+ }
+ }
+ /* save current lookuped var name */
+ cur = prev_chk_var_recursive;
+ cur_save.var = t->var;
+ cur_save.next = cur;
+ prev_chk_var_recursive = &cur_save;
+
+ t->val = arith (p, &errcode, math_hooks);
+ /* restore previous ptr after recursiving */
+ prev_chk_var_recursive = cur;
+ return errcode;
+ }
+ /* allow undefined var as 0 */
+ t->val = 0;
+ }
+ return 0;
+}
+
+/* "applying" a token means performing it on the top elements on the integer
+ * stack. For a unary operator it will only change the top element, but a
+ * binary operator will pop two arguments and push a result */
+static int
+arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr, a_e_h_t *math_hooks)
+{
+ v_n_t *numptr_m1;
+ arith_t numptr_val, rez;
+ int ret_arith_lookup_val;
+
+ /* There is no operator that can work without arguments */
+ if (NUMPTR == numstack) goto err;
+ numptr_m1 = NUMPTR - 1;
+
+ /* check operand is var with noninteger value */
+ ret_arith_lookup_val = arith_lookup_val(numptr_m1, math_hooks);
+ if (ret_arith_lookup_val)
+ return ret_arith_lookup_val;
+
+ rez = numptr_m1->val;
+ if (op == TOK_UMINUS)
+ rez *= -1;
+ else if (op == TOK_NOT)
+ rez = !rez;
+ else if (op == TOK_BNOT)
+ rez = ~rez;
+ else if (op == TOK_POST_INC || op == TOK_PRE_INC)
+ rez++;
+ else if (op == TOK_POST_DEC || op == TOK_PRE_DEC)
+ rez--;
+ else if (op != TOK_UPLUS) {
+ /* Binary operators */
+
+ /* check and binary operators need two arguments */
+ if (numptr_m1 == numstack) goto err;
+
+ /* ... and they pop one */
+ --NUMPTR;
+ numptr_val = rez;
+ if (op == TOK_CONDITIONAL) {
+ if (!numptr_m1->contidional_second_val_initialized) {
+ /* protect $((expr1 ? expr2)) without ": expr" */
+ goto err;
+ }
+ rez = numptr_m1->contidional_second_val;
+ } else if (numptr_m1->contidional_second_val_initialized) {
+ /* protect $((expr1 : expr2)) without "expr ? " */
+ goto err;
+ }
+ numptr_m1 = NUMPTR - 1;
+ if (op != TOK_ASSIGN) {
+ /* check operand is var with noninteger value for not '=' */
+ ret_arith_lookup_val = arith_lookup_val(numptr_m1, math_hooks);
+ if (ret_arith_lookup_val)
+ return ret_arith_lookup_val;
+ }
+ if (op == TOK_CONDITIONAL) {
+ numptr_m1->contidional_second_val = rez;
+ }
+ rez = numptr_m1->val;
+ if (op == TOK_BOR || op == TOK_OR_ASSIGN)
+ rez |= numptr_val;
+ else if (op == TOK_OR)
+ rez = numptr_val || rez;
+ else if (op == TOK_BAND || op == TOK_AND_ASSIGN)
+ rez &= numptr_val;
+ else if (op == TOK_BXOR || op == TOK_XOR_ASSIGN)
+ rez ^= numptr_val;
+ else if (op == TOK_AND)
+ rez = rez && numptr_val;
+ else if (op == TOK_EQ)
+ rez = (rez == numptr_val);
+ else if (op == TOK_NE)
+ rez = (rez != numptr_val);
+ else if (op == TOK_GE)
+ rez = (rez >= numptr_val);
+ else if (op == TOK_RSHIFT || op == TOK_RSHIFT_ASSIGN)
+ rez >>= numptr_val;
+ else if (op == TOK_LSHIFT || op == TOK_LSHIFT_ASSIGN)
+ rez <<= numptr_val;
+ else if (op == TOK_GT)
+ rez = (rez > numptr_val);
+ else if (op == TOK_LT)
+ rez = (rez < numptr_val);
+ else if (op == TOK_LE)
+ rez = (rez <= numptr_val);
+ else if (op == TOK_MUL || op == TOK_MUL_ASSIGN)
+ rez *= numptr_val;
+ else if (op == TOK_ADD || op == TOK_PLUS_ASSIGN)
+ rez += numptr_val;
+ else if (op == TOK_SUB || op == TOK_MINUS_ASSIGN)
+ rez -= numptr_val;
+ else if (op == TOK_ASSIGN || op == TOK_COMMA)
+ rez = numptr_val;
+ else if (op == TOK_CONDITIONAL_SEP) {
+ if (numptr_m1 == numstack) {
+ /* protect $((expr : expr)) without "expr ? " */
+ goto err;
+ }
+ numptr_m1->contidional_second_val_initialized = op;
+ numptr_m1->contidional_second_val = numptr_val;
+ } else if (op == TOK_CONDITIONAL) {
+ rez = rez ?
+ numptr_val : numptr_m1->contidional_second_val;
+ } else if (op == TOK_EXPONENT) {
+ if (numptr_val < 0)
+ return -3; /* exponent less than 0 */
+ else {
+ arith_t c = 1;
+
+ if (numptr_val)
+ while (numptr_val--)
+ c *= rez;
+ rez = c;
+ }
+ } else if (numptr_val==0) /* zero divisor check */
+ return -2;
+ else if (op == TOK_DIV || op == TOK_DIV_ASSIGN)
+ rez /= numptr_val;
+ else if (op == TOK_REM || op == TOK_REM_ASSIGN)
+ rez %= numptr_val;
+ }
+ if (tok_have_assign(op)) {
+ char buf[sizeof(arith_t_type)*3 + 2];
+
+ if (numptr_m1->var == NULL) {
+ /* Hmm, 1=2 ? */
+ goto err;
+ }
+ /* save to shell variable */
+ snprintf(buf, sizeof(buf), arith_t_fmt, (arith_t_type) rez);
+ setvar(numptr_m1->var, buf, 0);
+ /* after saving, make previous value for v++ or v-- */
+ if (op == TOK_POST_INC)
+ rez--;
+ else if (op == TOK_POST_DEC)
+ rez++;
+ }
+ numptr_m1->val = rez;
+ /* protect geting var value, is number now */
+ numptr_m1->var = NULL;
+ return 0;
+ err:
+ return -1;
+}
+
+/* longest must be first */
+static const char op_tokens[] ALIGN1 = {
+ '<','<','=',0, TOK_LSHIFT_ASSIGN,
+ '>','>','=',0, TOK_RSHIFT_ASSIGN,
+ '<','<', 0, TOK_LSHIFT,
+ '>','>', 0, TOK_RSHIFT,
+ '|','|', 0, TOK_OR,
+ '&','&', 0, TOK_AND,
+ '!','=', 0, TOK_NE,
+ '<','=', 0, TOK_LE,
+ '>','=', 0, TOK_GE,
+ '=','=', 0, TOK_EQ,
+ '|','=', 0, TOK_OR_ASSIGN,
+ '&','=', 0, TOK_AND_ASSIGN,
+ '*','=', 0, TOK_MUL_ASSIGN,
+ '/','=', 0, TOK_DIV_ASSIGN,
+ '%','=', 0, TOK_REM_ASSIGN,
+ '+','=', 0, TOK_PLUS_ASSIGN,
+ '-','=', 0, TOK_MINUS_ASSIGN,
+ '-','-', 0, TOK_POST_DEC,
+ '^','=', 0, TOK_XOR_ASSIGN,
+ '+','+', 0, TOK_POST_INC,
+ '*','*', 0, TOK_EXPONENT,
+ '!', 0, TOK_NOT,
+ '<', 0, TOK_LT,
+ '>', 0, TOK_GT,
+ '=', 0, TOK_ASSIGN,
+ '|', 0, TOK_BOR,
+ '&', 0, TOK_BAND,
+ '*', 0, TOK_MUL,
+ '/', 0, TOK_DIV,
+ '%', 0, TOK_REM,
+ '+', 0, TOK_ADD,
+ '-', 0, TOK_SUB,
+ '^', 0, TOK_BXOR,
+ /* uniq */
+ '~', 0, TOK_BNOT,
+ ',', 0, TOK_COMMA,
+ '?', 0, TOK_CONDITIONAL,
+ ':', 0, TOK_CONDITIONAL_SEP,
+ ')', 0, TOK_RPAREN,
+ '(', 0, TOK_LPAREN,
+ 0
+};
+/* ptr to ")" */
+#define endexpression (&op_tokens[sizeof(op_tokens)-7])
+
+arith_t
+arith(const char *expr, int *perrcode, a_e_h_t *math_hooks)
+{
+ char arithval; /* Current character under analysis */
+ operator lasttok, op;
+ operator prec;
+ operator *stack, *stackptr;
+ const char *p = endexpression;
+ int errcode;
+ v_n_t *numstack, *numstackptr;
+ unsigned datasizes = strlen(expr) + 2;
+
+ /* Stack of integers */
+ /* The proof that there can be no more than strlen(startbuf)/2+1 integers
+ * in any given correct or incorrect expression is left as an exercise to
+ * the reader. */
+ numstackptr = numstack = alloca((datasizes / 2) * sizeof(numstack[0]));
+ /* Stack of operator tokens */
+ stackptr = stack = alloca(datasizes * sizeof(stack[0]));
+
+ *stackptr++ = lasttok = TOK_LPAREN; /* start off with a left paren */
+ *perrcode = errcode = 0;
+
+ while (1) {
+ arithval = *expr;
+ if (arithval == 0) {
+ if (p == endexpression) {
+ /* Null expression. */
+ return 0;
+ }
+
+ /* This is only reached after all tokens have been extracted from the
+ * input stream. If there are still tokens on the operator stack, they
+ * are to be applied in order. At the end, there should be a final
+ * result on the integer stack */
+
+ if (expr != endexpression + 1) {
+ /* If we haven't done so already, */
+ /* append a closing right paren */
+ expr = endexpression;
+ /* and let the loop process it. */
+ continue;
+ }
+ /* At this point, we're done with the expression. */
+ if (numstackptr != numstack+1) {
+ /* ... but if there isn't, it's bad */
+ err:
+ *perrcode = -1;
+ return *perrcode;
+ }
+ if (numstack->var) {
+ /* expression is $((var)) only, lookup now */
+ errcode = arith_lookup_val(numstack, math_hooks);
+ }
+ ret:
+ *perrcode = errcode;
+ return numstack->val;
+ }
+
+ /* Continue processing the expression. */
+ if (arith_isspace(arithval)) {
+ /* Skip whitespace */
+ goto prologue;
+ }
+ p = endofname(expr);
+ if (p != expr) {
+ size_t var_name_size = (p-expr) + 1; /* trailing zero */
+
+ numstackptr->var = alloca(var_name_size);
+ safe_strncpy(numstackptr->var, expr, var_name_size);
+ expr = p;
+ num:
+ numstackptr->contidional_second_val_initialized = 0;
+ numstackptr++;
+ lasttok = TOK_NUM;
+ continue;
+ }
+ if (isdigit(arithval)) {
+ numstackptr->var = NULL;
+ numstackptr->val = strto_arith_t(expr, (char **) &expr, 0);
+ goto num;
+ }
+ for (p = op_tokens; ; p++) {
+ const char *o;
+
+ if (*p == 0) {
+ /* strange operator not found */
+ goto err;
+ }
+ for (o = expr; *p && *o == *p; p++)
+ o++;
+ if (!*p) {
+ /* found */
+ expr = o - 1;
+ break;
+ }
+ /* skip tail uncompared token */
+ while (*p)
+ p++;
+ /* skip zero delim */
+ p++;
+ }
+ op = p[1];
+
+ /* post grammar: a++ reduce to num */
+ if (lasttok == TOK_POST_INC || lasttok == TOK_POST_DEC)
+ lasttok = TOK_NUM;
+
+ /* Plus and minus are binary (not unary) _only_ if the last
+ * token was as number, or a right paren (which pretends to be
+ * a number, since it evaluates to one). Think about it.
+ * It makes sense. */
+ if (lasttok != TOK_NUM) {
+ switch (op) {
+ case TOK_ADD:
+ op = TOK_UPLUS;
+ break;
+ case TOK_SUB:
+ op = TOK_UMINUS;
+ break;
+ case TOK_POST_INC:
+ op = TOK_PRE_INC;
+ break;
+ case TOK_POST_DEC:
+ op = TOK_PRE_DEC;
+ break;
+ }
+ }
+ /* We don't want a unary operator to cause recursive descent on the
+ * stack, because there can be many in a row and it could cause an
+ * operator to be evaluated before its argument is pushed onto the
+ * integer stack. */
+ /* But for binary operators, "apply" everything on the operator
+ * stack until we find an operator with a lesser priority than the
+ * one we have just extracted. */
+ /* Left paren is given the lowest priority so it will never be
+ * "applied" in this way.
+ * if associativity is right and priority eq, applied also skip
+ */
+ prec = PREC(op);
+ if ((prec > 0 && prec < UNARYPREC) || prec == SPEC_PREC) {
+ /* not left paren or unary */
+ if (lasttok != TOK_NUM) {
+ /* binary op must be preceded by a num */
+ goto err;
+ }
+ while (stackptr != stack) {
+ if (op == TOK_RPAREN) {
+ /* The algorithm employed here is simple: while we don't
+ * hit an open paren nor the bottom of the stack, pop
+ * tokens and apply them */
+ if (stackptr[-1] == TOK_LPAREN) {
+ --stackptr;
+ /* Any operator directly after a */
+ lasttok = TOK_NUM;
+ /* close paren should consider itself binary */
+ goto prologue;
+ }
+ } else {
+ operator prev_prec = PREC(stackptr[-1]);
+
+ convert_prec_is_assing(prec);
+ convert_prec_is_assing(prev_prec);
+ if (prev_prec < prec)
+ break;
+ /* check right assoc */
+ if (prev_prec == prec && is_right_associativity(prec))
+ break;
+ }
+ errcode = arith_apply(*--stackptr, numstack, &numstackptr, math_hooks);
+ if (errcode) goto ret;
+ }
+ if (op == TOK_RPAREN) {
+ goto err;
+ }
+ }
+
+ /* Push this operator to the stack and remember it. */
+ *stackptr++ = lasttok = op;
+ prologue:
+ ++expr;
+ } /* while */
+}
+
+/*-
+ * Copyright (c) 1989, 1991, 1993, 1994
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
shell/math.h+101 -0
@@ -0,0 +1,101 @@
+/* math.h - interface to shell math "library" -- this allows shells to share
+ * the implementation of arithmetic $((...)) expansions.
+ *
+ * This aims to be a POSIX shell math library as documented here:
+ * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_04
+ *
+ * See math.c for internal documentation.
+ */
+
+/* The math library has just one function:
+ *
+ * arith_t arith(const char *expr, int *perrcode, arith_eval_hooks_t *hooks);
+ *
+ * The first argument is the math string to parse. All normal expansions must
+ * be done already. i.e. no dollar symbols should be present.
+ *
+ * The second argument is a semi-detailed error description in case something
+ * goes wrong in the parsing steps. Currently, those values are (for
+ * compatibility, you should assume all negative values are errors):
+ * 0 - no errors (yay!)
+ * -1 - unspecified problem
+ * -2 - divide by zero
+ * -3 - exponent less than 0
+ * -5 - expression recursion loop detected
+ *
+ * The third argument is a struct pointer of hooks for your shell (see below).
+ *
+ * The function returns the answer to the expression. So if you called it
+ * with the expression:
+ * "1 + 2 + 3"
+ * You would obviously get back 6.
+ */
+
+/* To add support to a shell, you need to implement three functions:
+ *
+ * lookupvar() - look up and return the value of a variable
+ *
+ * If the shell does:
+ * foo=123
+ * Then the code:
+ * const char *val = lookupvar("foo");
+ * Will result in val pointing to "123"
+ *
+ * setvar() - set a variable to some value
+ *
+ * If the arithmetic expansion does something like:
+ * $(( i = 1))
+ * Then the math code will make a call like so:
+ * setvar("i", "1", 0);
+ * The storage for the first two parameters are not allocated, so your
+ * shell implementation will most likely need to strdup() them to save.
+ *
+ * endofname() - return the end of a variable name from input
+ *
+ * The arithmetic code does not know about variable naming conventions.
+ * So when it is given an experession, it knows something is not numeric,
+ * but it is up to the shell to dictate what is a valid identifiers.
+ * So when it encounters something like:
+ * $(( some_var + 123 ))
+ * It will make a call like so:
+ * end = endofname("some_var + 123");
+ * So the shell needs to scan the input string and return a pointer to the
+ * first non-identifier string. In this case, it should return the input
+ * pointer with an offset pointing to the first space. The typical
+ * implementation will return the offset of first char that does not match
+ * the regex (in C locale): ^[a-zA-Z_][a-zA-Z_0-9]*
+ */
+
+/* To make your life easier when dealing with optional 64bit math support,
+ * rather than assume that the type is "signed long" and you can always
+ * use "%ld" to scan/print the value, use the arith_t helper defines. See
+ * below for the exact things that are available.
+ */
+
+#ifndef _SHELL_MATH_
+#define _SHELL_MATH_
+
+#if ENABLE_SH_MATH_SUPPORT_64
+typedef int64_t arith_t;
+#define arith_t_type long long
+#define arith_t_fmt "%lld"
+#define strto_arith_t strtoll
+#else
+typedef long arith_t;
+#define arith_t_type long
+#define arith_t_fmt "%ld"
+#define strto_arith_t strtol
+#endif
+
+typedef const char *(*arith_var_lookup_t)(const char *name);
+typedef void (*arith_var_set_t)(const char *name, const char *val, int flags);
+typedef char *(*arith_var_endofname_t)(const char *name);
+typedef struct arith_eval_hooks {
+ arith_var_lookup_t lookupvar;
+ arith_var_set_t setvar;
+ arith_var_endofname_t endofname;
+} arith_eval_hooks_t;
+
+arith_t arith(const char *expr, int *perrcode, arith_eval_hooks_t*);
+
+#endif