diff options
author | Eric Andersen <andersen@codepoet.org> | 2003-08-06 15:20:52 +0400 |
---|---|---|
committer | Eric Andersen <andersen@codepoet.org> | 2003-08-06 15:20:52 +0400 |
commit | 9089844382a87290143ec414cfea703bcc31e9d8 (patch) | |
tree | dd507d9dfc45625d953748ffc7c361bd1f025ca6 /shell | |
parent | dc19af4179161bdc80ea4d382a116e916a43ac9d (diff) |
Latest dash update from vodz
Diffstat (limited to 'shell')
-rw-r--r-- | shell/ash.c | 1061 |
1 files changed, 909 insertions, 152 deletions
diff --git a/shell/ash.c b/shell/ash.c index 2b99a3254..74c33381a 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -26,13 +26,20 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * + * 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 <aaronl@vitelus.com> * - * Modified by Vladimir Oleynik <dzo@simtreas.ru> to be used in busybox - * + * Modified by Vladimir Oleynik <dzo@simtreas.ru> (c) 2001-2003 to be + * used in busybox and size optimizations, + * support locale, rewrited arith (see notes to this) * - * Original BSD copyright notice is retained at the end of this file. */ + /* * The follow should be set to reflect the type of system you have: * JOBS -> 1 if you have Berkeley job control, 0 otherwise. @@ -83,8 +90,6 @@ #include <sysexits.h> #include <fnmatch.h> -#include <glob.h> - #include "busybox.h" @@ -544,7 +549,7 @@ static int parsenleft; /* copy of parsefile->nleft */ static int parselleft; /* copy of parsefile->lleft */ /* next character in input buffer */ -static char *parsenextc; /* copy of parsefile->nextc */ +static char *parsenextc; /* copy of parsefile->nextc */ static struct parsefile basepf; /* top level input file */ static char basebuf[IBUFSIZ]; /* buffer for top level input file */ static struct parsefile *parsefile = &basepf; /* current input file */ @@ -588,16 +593,12 @@ static const char homestr[] = "HOME"; #define TRACEV(param) #endif -#if defined(__GNUC__) && __GNUC__ < 3 -#define va_copy __va_copy -#endif - #if !defined(__GNUC__) || (__GNUC__ == 2 && __GNUC_MINOR__ < 96) #define __builtin_expect(x, expected_value) (x) #endif #define likely(x) __builtin_expect((x),1) -#define unlikely(x) __builtin_expect((x),0) + #define TEOF 0 #define TNL 1 @@ -1223,9 +1224,6 @@ static int dotcmd(int, char **); static int evalcmd(int, char **); static int execcmd(int, char **); static int exitcmd(int, char **); -#ifdef CONFIG_ASH_MATH_SUPPORT -static int expcmd(int, char **); -#endif static int exportcmd(int, char **); static int falsecmd(int, char **); #ifdef JOBS @@ -1241,6 +1239,9 @@ static int helpcmd(int argc, char **argv); #ifdef JOBS static int jobscmd(int, char **); #endif +#ifdef CONFIG_ASH_MATH_SUPPORT +static int letcmd(int, char **); +#endif static int localcmd(int, char **); static int pwdcmd(int, char **); static int readcmd(int, char **); @@ -1345,9 +1346,6 @@ static const struct builtincmd builtincmd[] = { { BUILTIN_SPEC_REG "eval", evalcmd }, { BUILTIN_SPEC_REG "exec", execcmd }, { BUILTIN_SPEC_REG "exit", exitcmd }, -#ifdef CONFIG_ASH_MATH_SUPPORT - { BUILTIN_NOSPEC "exp", expcmd }, -#endif { BUILTIN_SPEC_REG_ASSG "export", exportcmd }, { BUILTIN_REGULAR "false", falsecmd }, #ifdef JOBS @@ -1365,7 +1363,7 @@ static const struct builtincmd builtincmd[] = { { BUILTIN_REGULAR "kill", killcmd }, #endif #ifdef CONFIG_ASH_MATH_SUPPORT - { BUILTIN_NOSPEC "let", expcmd }, + { BUILTIN_NOSPEC "let", letcmd }, #endif { BUILTIN_ASSIGN "local", localcmd }, { BUILTIN_NOSPEC "pwd", pwdcmd }, @@ -1421,7 +1419,6 @@ static void defun(char *, union node *); static void unsetfunc(const char *); #ifdef CONFIG_ASH_MATH_SUPPORT -/* From arith.y */ static int dash_arith(const char *); #endif @@ -1482,8 +1479,7 @@ static void change_lc_ctype(const char *value); #define VTABSIZE 39 -static const char defpathvar[] = - "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"; +static const char defpathvar[] = "PATH=/usr/local/bin:/usr/bin:/sbin:/bin"; #ifdef IFS_BROKEN static const char defifsvar[] = "IFS= \t\n"; #define defifs (defifsvar + 4) @@ -4522,8 +4518,6 @@ static void removerecordregions(int); static void ifsbreakup(char *, struct arglist *); static void ifsfree(void); static void expandmeta(struct strlist *, int); -static void addglob(const glob_t *); -static void addfname(char *); static int patmatch(char *, const char *); static int cvtnum(long); @@ -4536,7 +4530,7 @@ static void varunset(const char *, const char *, const char *, int) #define pmatch(a, b) !fnmatch((a), (b), 0) /* - * Prepare a pattern for a glob(3) call. + * Prepare a pattern for a expmeta (internal glob(3)) call. * * Returns an stalloced string. */ @@ -4625,7 +4619,6 @@ expandarg(union node *arg, struct arglist *arglist, int flag) } - /* * Perform variable and command substitution. If EXP_FULL is set, output CTLESC * characters to allow for further processing. Otherwise treat @@ -4987,10 +4980,9 @@ read: static char * -scanleft( - char *startp, char *rmesc, char *rmescend, char *str, int quotes, - int zero -) { +scanleft(char *startp, char *rmesc, char *rmescend, char *str, int quotes, + int zero) +{ char *loc; char *loc2; char c; @@ -5019,10 +5011,9 @@ scanleft( static char * -scanright( - char *startp, char *rmesc, char *rmescend, char *str, int quotes, - int zero -) { +scanright(char *startp, char *rmesc, char *rmescend, char *str, int quotes, + int zero) +{ int esc = 0; char *loc; char *loc2; @@ -5330,7 +5321,6 @@ varisset(char *name, int nulok) } - /* * Put a string on the stack. */ @@ -5361,7 +5351,6 @@ strtodest(const char *p, int syntax, int quotes) } - /* * Add the value of a specialized variable to the stack string. */ @@ -5437,7 +5426,6 @@ param: } - /* * Record the fact that we have to scan this region of the * string for IFS characters. @@ -5464,7 +5452,6 @@ recordregion(int start, int end, int nulonly) } - /* * Break the argument string into pieces based upon IFS and add the * strings to the argument list. The regions of the string to be @@ -5573,86 +5560,254 @@ ifsfree(void) INTON; } +static void expmeta(char *, char *); +static struct strlist *expsort(struct strlist *); +static struct strlist *msort(struct strlist *, int); +static char *expdir; -/* - * Expand shell metacharacters. At this point, the only control characters - * should be escapes. The results are stored in the list exparg. - */ static void -expandmeta(str, flag) - struct strlist *str; - int flag; +expandmeta(struct strlist *str, int flag) { + static const char metachars[] = { + '*', '?', '[', 0 + }; /* TODO - EXP_REDIR */ while (str) { - const char *p; - glob_t pglob; - int i; + struct strlist **savelastp; + struct strlist *sp; + char *p; if (fflag) goto nometa; + if (!strpbrk(str->text, metachars)) + goto nometa; + savelastp = exparg.lastp; + INTOFF; p = preglob(str->text, 0, RMESCAPE_ALLOC | RMESCAPE_HEAP); - i = glob(p, GLOB_NOMAGIC, 0, &pglob); + { + int i = strlen(str->text); + expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ + } + + expmeta(expdir, p); + ckfree(expdir); if (p != str->text) ckfree(p); - switch (i) { - case 0: - if (!(pglob.gl_flags & GLOB_MAGCHAR)) - goto nometa2; - addglob(&pglob); - globfree(&pglob); - INTON; - break; - case GLOB_NOMATCH: -nometa2: - globfree(&pglob); - INTON; + INTON; + if (exparg.lastp == savelastp) { + /* + * no matches + */ nometa: *exparg.lastp = str; rmescapes(str->text); exparg.lastp = &str->next; - break; - default: /* GLOB_NOSPACE */ - error(bb_msg_memory_exhausted); + } else { + *exparg.lastp = NULL; + *savelastp = sp = expsort(*savelastp); + while (sp->next != NULL) + sp = sp->next; + exparg.lastp = &sp->next; } str = str->next; } } - /* - * Add the result of glob(3) to the list. + * Add a file name to the list. */ static void -addglob(pglob) - const glob_t *pglob; +addfname(const char *name) { - char **p = pglob->gl_pathv; + struct strlist *sp; - do { - addfname(*p); - } while (*++p); + sp = (struct strlist *)stalloc(sizeof *sp); + sp->text = sstrdup(name); + *exparg.lastp = sp; + exparg.lastp = &sp->next; } /* - * Add a file name to the list. + * Do metacharacter (i.e. *, ?, [...]) expansion. */ static void -addfname(char *name) +expmeta(char *enddir, char *name) { + char *p; + const char *cp; + char *start; + char *endname; + int metaflag; + struct stat64 statb; + DIR *dirp; + struct dirent *dp; + int atend; + int matchdot; + + metaflag = 0; + start = name; + for (p = name; *p; p++) { + if (*p == '*' || *p == '?') + metaflag = 1; + else if (*p == '[') { + char *q = p + 1; + if (*q == '!') + q++; + for (;;) { + if (*q == '\\') + q++; + if (*q == '/' || *q == '\0') + break; + if (*++q == ']') { + metaflag = 1; + break; + } + } + } else if (*p == '\\') + p++; + else if (*p == '/') { + if (metaflag) + goto out; + start = p + 1; + } + } +out: + if (metaflag == 0) { /* we've reached the end of the file name */ + if (enddir != expdir) + metaflag++; + p = name; + do { + if (*p == '\\') + p++; + *enddir++ = *p; + } while (*p++); + if (metaflag == 0 || lstat64(expdir, &statb) >= 0) + addfname(expdir); + return; + } + endname = p; + if (name < start) { + p = name; + do { + if (*p == '\\') + p++; + *enddir++ = *p++; + } while (p < start); + } + if (enddir == expdir) { + cp = "."; + } else if (enddir == expdir + 1 && *expdir == '/') { + cp = "/"; + } else { + cp = expdir; + enddir[-1] = '\0'; + } + if ((dirp = opendir(cp)) == NULL) + return; + if (enddir != expdir) + enddir[-1] = '/'; + if (*endname == 0) { + atend = 1; + } else { + atend = 0; + *endname++ = '\0'; + } + matchdot = 0; + p = start; + if (*p == '\\') + p++; + if (*p == '.') + matchdot++; + while (! intpending && (dp = readdir(dirp)) != NULL) { + if (dp->d_name[0] == '.' && ! matchdot) + continue; + if (pmatch(start, dp->d_name)) { + if (atend) { + scopy(dp->d_name, enddir); + addfname(expdir); + } else { + for (p = enddir, cp = dp->d_name; + (*p++ = *cp++) != '\0';) + continue; + p[-1] = '/'; + expmeta(p, endname); + } + } + } + closedir(dirp); + if (! atend) + endname[-1] = '/'; +} + +/* + * Sort the results of file name expansion. It calculates the number of + * strings to sort and then calls msort (short for merge sort) to do the + * work. + */ + +static struct strlist * +expsort(struct strlist *str) +{ + int len; struct strlist *sp; - sp = (struct strlist *)stalloc(sizeof *sp); - sp->text = sstrdup(name); - *exparg.lastp = sp; - exparg.lastp = &sp->next; + len = 0; + for (sp = str ; sp ; sp = sp->next) + len++; + return msort(str, len); +} + + +static struct strlist * +msort(struct strlist *list, int len) +{ + struct strlist *p, *q = NULL; + struct strlist **lpp; + int half; + int n; + + if (len <= 1) + return list; + half = len >> 1; + p = list; + for (n = half ; --n >= 0 ; ) { + q = p; + p = p->next; + } + q->next = NULL; /* terminate first half of list */ + q = msort(list, half); /* sort first half of list */ + p = msort(p, len - half); /* sort second half */ + lpp = &list; + for (;;) { +#ifdef CONFIG_LOCALE_SUPPORT + if (strcoll(p->text, q->text) < 0) +#else + if (strcmp(p->text, q->text) < 0) +#endif + { + *lpp = p; + lpp = &p->next; + if ((p = *lpp) == NULL) { + *lpp = q; + break; + } + } else { + *lpp = q; + lpp = &q->next; + if ((q = *lpp) == NULL) { + *lpp = p; + break; + } + } + } + return list; } @@ -5736,7 +5891,6 @@ copy: } - /* * See if a pattern matches in a case statement. */ @@ -5790,12 +5944,12 @@ varunset(const char *end, const char *var, const char *umsg, int varflags) } error("%.*s: %s%s", end - var - 1, var, msg, tail); } -/* $NetBSD: input.c,v 1.37 2002/11/24 22:35:40 christos Exp $ */ +/* $NetBSD: input.c,v 1.37 2002/11/24 22:35:40 christos Exp $ */ /* - * This file implements the input routines used by the parser. + * This implements the input routines used by the parser. */ #define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */ @@ -6147,7 +6301,6 @@ setinputstring(char *string) } - /* * To handle the "." command, a stack of input files is used. Pushfile * adds a new entry to the stack and popfile restores the previous level. @@ -6205,7 +6358,6 @@ popallfiles(void) } - /* * Close the file(s) that the shell is reading commands from. Called * after a fork is done. @@ -6220,8 +6372,8 @@ closescript(void) parsefile->fd = 0; } } -/* $NetBSD: jobs.c,v 1.56 2002/11/25 12:13:03 agc Exp $ */ +/* $NetBSD: jobs.c,v 1.56 2002/11/25 12:13:03 agc Exp $ */ /* mode flags for set_curjob */ #define CUR_DELETE 2 @@ -6382,9 +6534,7 @@ close: } static int -killcmd(argc, argv) - int argc; - char **argv; +killcmd(int argc, char **argv) { int signo = -1; int list = 0; @@ -6625,8 +6775,7 @@ showjob(FILE *out, struct job *jp, int mode) col = fmtstr(s, 48, " |\n%*c%d ", indent, ' ', ps->pid) - 3; start: - fprintf( - out, "%s%*c%s", + fprintf(out, "%s%*c%s", s, 33 - col >= 0 ? 33 - col : 0, ' ', ps->cmd ); if (!(mode & SHOW_PID)) { @@ -6781,7 +6930,6 @@ out: } - /* * Convert a job name to a job structure. */ @@ -6866,7 +7014,6 @@ err: } - /* * Return a new job structure. * Called with interrupts off. @@ -7260,10 +7407,10 @@ out: } - /* * return 1 if there are stopped jobs, otherwise 0 */ + int stoppedjobs(void) { @@ -7468,7 +7615,6 @@ cmdlist(union node *np, int sep) } } - static void cmdputs(const char *s) { @@ -7749,7 +7895,7 @@ ash_main(int argc, char **argv) if (e == EXEXIT || state == 0 || iflag == 0 || ! rootshell) exitshell(); - if (e == EXINT ) { + if (e == EXINT) { outcslow('\n', stderr); } popstackmark(&smark); @@ -7814,7 +7960,6 @@ state3: evalstring(minusc, 0); if (sflag || minusc == NULL) { -state4: /* XXX ??? - why isn't this before the "if" statement */ #ifdef CONFIG_FEATURE_COMMAND_SAVEHISTORY if ( iflag ) { const char *hp = lookupvar("HISTFILE"); @@ -7823,6 +7968,7 @@ state4: /* XXX ??? - why isn't this before the "if" statement */ load_history ( hp ); } #endif +state4: /* XXX ??? - why isn't this before the "if" statement */ cmdloop(1); } #if PROFILE @@ -7895,7 +8041,6 @@ cmdloop(int top) } - /* * Read /etc/profile or .profile. Return on error. */ @@ -7931,7 +8076,6 @@ read_profile(const char *name) } - /* * Read a file containing shell functions. */ @@ -8019,35 +8163,24 @@ exitcmd(int argc, char **argv) /* $NetBSD: memalloc.c,v 1.27 2003/01/22 20:36:04 dsl Exp $ */ /* - * Like malloc, but returns an error when out of space. + * Same for malloc, realloc, but returns an error when out of space. */ static pointer -ckmalloc(size_t nbytes) +ckrealloc(pointer p, size_t nbytes) { - pointer p; - - p = malloc(nbytes); + p = realloc(p, nbytes); if (p == NULL) error(bb_msg_memory_exhausted); return p; } - -/* - * Same for realloc. - */ - static pointer -ckrealloc(pointer p, size_t nbytes) +ckmalloc(size_t nbytes) { - p = realloc(p, nbytes); - if (p == NULL) - error(bb_msg_memory_exhausted); - return p; + return ckrealloc(NULL, nbytes); } - /* * Make a copy of a string in safe storage. */ @@ -8120,7 +8253,6 @@ stunalloc(pointer p) } - void setstackmark(struct stackmark *mark) { @@ -8327,7 +8459,6 @@ number(const char *s) } - /* * Check for a valid number. This should be elsewhere. */ @@ -8479,7 +8610,6 @@ calcsize(union node *n) } - static void sizenodelist(struct nodelist *lp) { @@ -8491,7 +8621,6 @@ sizenodelist(struct nodelist *lp) } - static union node * copynode(union node *n) { @@ -8601,7 +8730,6 @@ copynodelist(struct nodelist *lp) } - static char * nodesavestr(char *s) { @@ -8612,7 +8740,6 @@ nodesavestr(char *s) } - /* * Free a parse tree. */ @@ -8775,7 +8902,6 @@ options(int cmdline) } - static void setoption(int flag, int val) { @@ -10669,7 +10795,7 @@ noexpand(char *text) char * endofname(const char *name) - { +{ char *p; p = (char *) name; @@ -10735,7 +10861,7 @@ static void setprompt(int whichprompt) static const char *const *findkwd(const char *s) { return bsearch(s, tokname_array + KWDOFFSET, - (sizeof(tokname_array) / sizeof(const char *)) - KWDOFFSET, + (sizeof(tokname_array) / sizeof(const char *)) - KWDOFFSET, sizeof(const char *), pstrcmp); } @@ -12122,7 +12248,6 @@ localcmd(int argc, char **argv) } - /* * Called after a function returns. * Interrupts must be off. @@ -12320,14 +12445,18 @@ int timescmd(int ac, char **av) { static int dash_arith(const char *s) { - long result = 0; + long result; int errcode = 0; INTOFF; result = arith(s, &errcode); if (errcode < 0) { - if (errcode == -2) + if (errcode == -3) + error("exponent less than 0"); + else if (errcode == -2) error("divide by zero"); + else if (errcode == -5) + error("expression recursion loop detected"); else synerror(s); } @@ -12338,41 +12467,26 @@ dash_arith(const char *s) /* - * The exp(1) builtin. + * The let builtin. partial stolen from GNU Bash, the Bourne Again SHell. + * Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc. + * + * Copyright (C) 2003 Vladimir Oleynik <dzo@simtreas.ru> */ + static int -expcmd(int argc, char **argv) +letcmd(int argc, char **argv) { - const char *p; - char *concat; char **ap; long i; - if (argc > 1) { - p = argv[1]; - if (argc > 2) { - /* - * concatenate arguments - */ - STARTSTACKSTR(concat); - ap = argv + 2; - for (;;) { - while (*p) - STPUTC(*p++, concat); - if ((p = *ap++) == NULL) - break; - STPUTC(' ', concat); - } - STPUTC('\0', concat); - p = grabstackstr(concat); - } - } else - p = nullstr; - - i = dash_arith(p); + ap = argv + 1; + if(!*ap) + error("expression expected"); + for (ap = argv + 1; *ap; ap++) { + i = dash_arith(*ap); + } - out1fmt("%ld\n", i); - return (! i); + return (!i); } #endif /* CONFIG_ASH_MATH_SUPPORT */ @@ -12697,6 +12811,649 @@ ulimitcmd(int argc, char **argv) return 0; } + +#ifdef CONFIG_ASH_MATH_SUPPORT + +/* Copyright (c) 2001 Aaron Lehmann <aaronl@vitelus.com> + + 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 writen in yacc. The supported operators are + * listed in #defines below. Parens, order of operations, and error handling + * are supported. This code is threadsafe. 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 explaination 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 desireable 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 <dzo@simtreas.ru> + * + * - 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 hexdecimal 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 accross 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 inline 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 inline int is_right_associativity(operator prec) +{ + return (prec == PREC(TOK_ASSIGN) || prec == PREC(TOK_EXPONENT) || + prec == PREC(TOK_CONDITIONAL)); +} + + +typedef struct ARITCH_VAR_NUM { + long val; + long contidional_second_val; + char contidional_second_val_initialized; + char *var; /* if NULL then is regular number, + else is varable name */ +} v_n_t; + + +typedef struct CHK_VAR_RECURSIVE_LOOPED { + const char *var; + struct CHK_VAR_RECURSIVE_LOOPED *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; + } else { + /* 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 inline int +arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr) +{ + long numptr_val; + v_n_t *numptr_m1; + long rez; + int ret_arith_lookup_val; + + if (NUMPTR == numstack) goto err; /* There is no operator that can work + without arguments */ + 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 { + long 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[32]; + + if(numptr_m1->var == NULL) { + /* Hmm, 1=2 ? */ + goto err; + } + /* save to shell variable */ + sprintf(buf, "%ld", 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 first */ +static const char op_tokens[] = { + '<','<','=',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] + + +extern long arith (const char *expr, int *perrcode) +{ + register char arithval; /* Current character under analysis */ + operator lasttok, op; + operator prec; + + const char *p = endexpression; + int errcode; + + size_t 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 excersize to + * the reader. */ + v_n_t *numstack = alloca(((datasizes)/2)*sizeof(v_n_t)), + *numstackptr = numstack; + /* Stack of operator tokens */ + operator *stack = alloca((datasizes) * sizeof(operator)), + *stackptr = stack; + + *stackptr++ = lasttok = TOK_LPAREN; /* start off with a left paren */ + *perrcode = errcode = 0; + + while(1) { + if ((arithval = *expr) == 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: + return (*perrcode = -1); + } + if(numstack->var) { + /* expression is $((var)) only, lookup now */ + errcode = arith_lookup_val(numstack); + } + ret: + *perrcode = errcode; + return numstack->val; + } else { + /* Continue processing the expression. */ + if (arith_isspace(arithval)) { + /* Skip whitespace */ + goto prologue; + } + if((p = endofname(expr)) != expr) { + int 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; + } else if (is_digit(arithval)) { + numstackptr->var = NULL; + numstackptr->val = strtol(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); + if(errcode) goto ret; + } + if (op == TOK_RPAREN) { + goto err; + } + } + + /* Push this operator to the stack and remember it. */ + *stackptr++ = lasttok = op; + + prologue: + ++expr; + } + } +} +#endif /* CONFIG_ASH_MATH_SUPPORT */ + + #ifdef DEBUG const char *bb_applet_name = "debug stuff usage"; int main(int argc, char **argv) |