Initial revision

1 files changed, 883 insertions, 0 deletions

diff --git a/Src/math.c b/Src/math.c
new file mode 100644
index 000000000..7a0a1f9bd
--- /dev/null
+++ b/Src/math.c
@@ -0,0 +1,883 @@
+/*
+ * math.c - mathematical expression evaluation
+ *
+ * This file is part of zsh, the Z shell.
+ *
+ * Copyright (c) 1992-1997 Paul Falstad
+ * All rights reserved.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and to distribute modified versions of this software for any
+ * purpose, provided that the above copyright notice and the following
+ * two paragraphs appear in all copies of this software.
+ *
+ * In no event shall Paul Falstad or the Zsh Development Group be liable
+ * to any party for direct, indirect, special, incidental, or consequential
+ * damages arising out of the use of this software and its documentation,
+ * even if Paul Falstad and the Zsh Development Group have been advised of
+ * the possibility of such damage.
+ *
+ * Paul Falstad and the Zsh Development Group specifically disclaim any
+ * warranties, including, but not limited to, the implied warranties of
+ * merchantability and fitness for a particular purpose.  The software
+ * provided hereunder is on an "as is" basis, and Paul Falstad and the
+ * Zsh Development Group have no obligation to provide maintenance,
+ * support, updates, enhancements, or modifications.
+ *
+ */
+
+#include "zsh.mdh"
+#include "math.pro"
+
+/* nonzero means we are not evaluating, just parsing */
+ 
+/**/
+int noeval;
+ 
+/* last input base we used */
+
+/**/
+int lastbase;
+ 
+static char *ptr;
+
+static long yyval;
+static LV yylval;
+
+static int mlevel = 0;
+
+/* != 0 means recognize unary plus, minus, etc. */
+
+static int unary = 1;
+
+/* LR = left-to-right associativity *
+ * RL = right-to-left associativity *
+ * BOO = short-circuiting boolean   */
+
+#define LR 0
+#define RL 1
+#define BOOL 2
+
+#define M_INPAR 0
+#define M_OUTPAR 1
+#define NOT 2
+#define COMP 3
+#define POSTPLUS 4
+#define POSTMINUS 5
+#define UPLUS 6
+#define UMINUS 7
+#define AND 8
+#define XOR 9
+#define OR 10
+#define MUL 11
+#define DIV 12
+#define MOD 13
+#define PLUS 14
+#define MINUS 15
+#define SHLEFT 16
+#define SHRIGHT 17
+#define LES 18
+#define LEQ 19
+#define GRE 20
+#define GEQ 21
+#define DEQ 22
+#define NEQ 23
+#define DAND 24
+#define DOR 25
+#define DXOR 26
+#define QUEST 27
+#define COLON 28
+#define EQ 29
+#define PLUSEQ 30
+#define MINUSEQ 31
+#define MULEQ 32
+#define DIVEQ 33
+#define MODEQ 34
+#define ANDEQ 35
+#define XOREQ 36
+#define OREQ 37
+#define SHLEFTEQ 38
+#define SHRIGHTEQ 39
+#define DANDEQ 40
+#define DOREQ 41
+#define DXOREQ 42
+#define COMMA 43
+#define EOI 44
+#define PREPLUS 45
+#define PREMINUS 46
+#define NUM 47
+#define ID 48
+#define POWER 49
+#define CID 50
+#define POWEREQ 51
+#define TOKCOUNT 52
+
+/* precedences */
+
+static int prec[TOKCOUNT] =
+{
+     1, 137,  2,  2,   2,
+     2,   2,  2,  4,   5,
+     6,   8,  8,  8,   9,
+     9,   3,  3, 10,  10,
+    10,  10, 11, 11,  12,
+    13,  13, 14, 14,  15,
+    15,  15, 15, 15,  15,
+    15,  15, 15, 15,  15,
+    15,  15, 15, 16, 200,
+     2,   2,  0,  0,   7,
+     0,  15
+};
+
+#define TOPPREC 16
+#define ARGPREC (TOPPREC-1)
+
+static int type[TOKCOUNT] =
+{
+    LR, LR, RL, RL, RL,
+    RL, RL, RL, LR, LR,
+    LR, LR, LR, LR, LR,
+    LR, LR, LR, LR, LR,
+    LR, LR, LR, LR, BOOL,
+    BOOL, LR, RL, RL, RL,
+    RL, RL, RL, RL, RL,
+    RL, RL, RL, RL, RL,
+    BOOL, BOOL, RL, RL, RL,
+    RL, RL, LR, LR, RL,
+    LR, RL
+};
+
+#define LVCOUNT 32
+
+/* list of lvalues (variables) */
+
+static int lvc;
+static char **lvals;
+
+
+/**/
+static int
+zzlex(void)
+{
+    int cct = 0;
+
+    for (;; cct = 0)
+	switch (*ptr++) {
+	case '+':
+	    if (*ptr == '+' && (unary || !ialnum(*ptr))) {
+		ptr++;
+		return (unary) ? PREPLUS : POSTPLUS;
+	    }
+	    if (*ptr == '=') {
+		unary = 1;
+		ptr++;
+		return PLUSEQ;
+	    }
+	    return (unary) ? UPLUS : PLUS;
+	case '-':
+	    if (*ptr == '-' && (unary || !ialnum(*ptr))) {
+		ptr++;
+		return (unary) ? PREMINUS : POSTMINUS;
+	    }
+	    if (*ptr == '=') {
+		unary = 1;
+		ptr++;
+		return MINUSEQ;
+	    }
+	    return (unary) ? UMINUS : MINUS;
+	case '(':
+	    unary = 1;
+	    return M_INPAR;
+	case ')':
+	    return M_OUTPAR;
+	case '!':
+	    if (*ptr == '=') {
+		unary = 1;
+		ptr++;
+		return NEQ;
+	    }
+	    return NOT;
+	case '~':
+	    return COMP;
+	case '&':
+	    unary = 1;
+	    if (*ptr == '&') {
+		if (*++ptr == '=') {
+		    ptr++;
+		    return DANDEQ;
+		}
+		return DAND;
+	    } else if (*ptr == '=') {
+		ptr++;
+		return ANDEQ;
+	    }
+	    return AND;
+	case '|':
+	    unary = 1;
+	    if (*ptr == '|') {
+		if (*++ptr == '=') {
+		    ptr++;
+		    return DOREQ;
+		}
+		return DOR;
+	    } else if (*ptr == '=') {
+		ptr++;
+		return OREQ;
+	    }
+	    return OR;
+	case '^':
+	    unary = 1;
+	    if (*ptr == '^') {
+		if (*++ptr == '=') {
+		    ptr++;
+		    return DXOREQ;
+		}
+		return DXOR;
+	    } else if (*ptr == '=') {
+		ptr++;
+		return XOREQ;
+	    }
+	    return XOR;
+	case '*':
+	    unary = 1;
+	    if (*ptr == '*') {
+		if (*++ptr == '=') {
+		    ptr++;
+		    return POWEREQ;
+		}
+		return POWER;
+	    }
+	    if (*ptr == '=') {
+		ptr++;
+		return MULEQ;
+	    }
+	    return MUL;
+	case '/':
+	    unary = 1;
+	    if (*ptr == '=') {
+		ptr++;
+		return DIVEQ;
+	    }
+	    return DIV;
+	case '%':
+	    unary = 1;
+	    if (*ptr == '=') {
+		ptr++;
+		return MODEQ;
+	    }
+	    return MOD;
+	case '<':
+	    unary = 1;
+	    if (*ptr == '<') {
+		if (*++ptr == '=') {
+		    ptr++;
+		    return SHLEFTEQ;
+		}
+		return SHLEFT;
+	    } else if (*ptr == '=') {
+		ptr++;
+		return LEQ;
+	    }
+	    return LES;
+	case '>':
+	    unary = 1;
+	    if (*ptr == '>') {
+		if (*++ptr == '=') {
+		    ptr++;
+		    return SHRIGHTEQ;
+		}
+		return SHRIGHT;
+	    } else if (*ptr == '=') {
+		ptr++;
+		return GEQ;
+	    }
+	    return GRE;
+	case '=':
+	    unary = 1;
+	    if (*ptr == '=') {
+		ptr++;
+		return DEQ;
+	    }
+	    return EQ;
+	case '$':
+	    unary = 0;
+	    yyval = mypid;
+	    return NUM;
+	case '?':
+	    if (unary) {
+		yyval = lastval;
+		unary = 0;
+		return NUM;
+	    }
+	    unary = 1;
+	    return QUEST;
+	case ':':
+	    unary = 1;
+	    return COLON;
+	case ',':
+	    unary = 1;
+	    return COMMA;
+	case '\0':
+	    unary = 1;
+	    ptr--;
+	    return EOI;
+	case '[':
+	    unary = 0;
+	    {
+		int base = zstrtol(ptr, &ptr, 10);
+
+		if (*ptr == ']')
+		    ptr++;
+		yyval = zstrtol(ptr, &ptr, lastbase = base);
+		return NUM;
+	    }
+	case ' ':
+	case '\t':
+	case '\n':
+	    break;
+	case '0':
+	    if (*ptr == 'x' || *ptr == 'X') {
+		unary = 0;
+		/* Should we set lastbase here? */
+		yyval = zstrtol(++ptr, &ptr, lastbase = 16);
+		return NUM;
+	    }
+	/* Fall through! */
+	default:
+	    if (idigit(*--ptr)) {
+		unary = 0;
+		yyval = zstrtol(ptr, &ptr, 10);
+
+		if (*ptr == '#') {
+		    ptr++;
+		    yyval = zstrtol(ptr, &ptr, lastbase = yyval);
+		}
+		return NUM;
+	    }
+	    if (*ptr == '#') {
+		if (*++ptr == '\\') {
+		    ptr++;
+		    yyval = *ptr == Meta ? *++ptr ^ 32 : *ptr;
+		    ptr++;
+		    unary = 0;
+		    return NUM;
+		}
+		cct = 1;
+	    }
+	    if (iident(*ptr)) {
+		char *p, q;
+
+		p = ptr;
+		if (lvc == LVCOUNT) {
+		    zerr("too many identifiers (complain to author)", NULL, 0);
+		    return EOI;
+		}
+		unary = 0;
+		while (iident(*++ptr));
+		if (*ptr == '[') {
+		    int l;
+		    for (ptr++, l = 1; *ptr && l; ptr++) {
+			if (*ptr == '[')
+			    l++;
+			if (*ptr == ']')
+			    l--;
+			if (*ptr == '\\' && ptr[1])
+			    ptr++;
+		    }
+		}
+		q = *ptr;
+		*ptr = '\0';
+		lvals[yylval = lvc++] = ztrdup(p);
+		*ptr = q;
+		return cct ? CID : ID;
+	    }
+	    else if (cct) {
+		yyval = poundgetfn(NULL);
+		unary = 0;
+		return NUM;
+	    }
+	    return EOI;
+	}
+}
+
+/* the value stack */
+
+#define STACKSZ 100
+static int mtok;			/* last token */
+static int sp = -1;			/* stack pointer */
+
+struct mathvalue {
+    LV lval;
+    long val;
+};
+
+static struct mathvalue *stack;
+
+/**/
+static void
+push(long val, LV lval)
+{
+    if (sp == STACKSZ - 1)
+	zerr("stack overflow", NULL, 0);
+    else
+	sp++;
+    stack[sp].val = val;
+    stack[sp].lval = lval;
+}
+
+
+/**/
+static long
+getcvar(LV s)
+{
+    char *t;
+
+    if (!(t = getsparam(lvals[s])))
+	return 0;
+    return STOUC(*t == Meta ? t[1] ^ 32 : *t);
+}
+
+
+/**/
+static long
+setvar(LV s, long v)
+{
+    if (s == -1 || s >= lvc) {
+	zerr("lvalue required", NULL, 0);
+	return 0;
+    }
+    if (noeval)
+	return v;
+    setiparam(lvals[s], v);
+    return v;
+}
+
+
+/**/
+static int
+notzero(long a)
+{
+    if (a == 0) {
+	zerr("division by zero", NULL, 0);
+	return 0;
+    }
+    return 1;
+}
+
+/* macro to pop two values off the value stack */
+#define pop2() { \
+	if (sp < 1) { \
+ 	    zerr("bad math expression: unbalanced stack", NULL, 0); \
+	    return; \
+	} \
+	b = stack[sp--].val; \
+	a = stack[sp--].val; \
+    }
+
+/* macro to pop three values off the value stack */
+#define pop3() { \
+	if (sp < 2) { \
+ 	    zerr("bad math expression: unbalanced stack", NULL, 0); \
+	    return; \
+	} \
+	c = stack[sp--].val; \
+	b = stack[sp--].val; \
+	a = stack[sp--].val; \
+    }
+
+#define nolval() {stack[sp].lval= -1;}
+#define pushv(X) { push(X,-1); }
+#define pop2lv() { pop2() lv = stack[sp+1].lval; }
+#define set(X) { push(setvar(lv,X),lv); }
+
+
+/**/
+void
+op(int what)
+{
+    long a, b, c;
+    LV lv;
+
+    if (sp < 0) {
+	zerr("bad math expression: stack empty", NULL, 0);
+	return;
+    }
+    switch (what) {
+    case NOT:
+	stack[sp].val = !stack[sp].val;
+	nolval();
+	break;
+    case COMP:
+	stack[sp].val = ~stack[sp].val;
+	nolval();
+	break;
+    case POSTPLUS:
+	(void)setvar(stack[sp].lval, stack[sp].val + 1);
+	break;
+    case POSTMINUS:
+	(void)setvar(stack[sp].lval, stack[sp].val - 1);
+	break;
+    case UPLUS:
+	nolval();
+	break;
+    case UMINUS:
+	stack[sp].val = -stack[sp].val;
+	nolval();
+	break;
+    case AND:
+	pop2();
+	pushv(a & b);
+	break;
+    case XOR:
+	pop2();
+	pushv(a ^ b);
+	break;
+    case OR:
+	pop2();
+	pushv(a | b);
+	break;
+    case MUL:
+	pop2();
+	pushv(a * b);
+	break;
+    case DIV:
+	pop2();
+	if (notzero(b))
+	    pushv(a / b);
+	break;
+    case MOD:
+	pop2();
+	if (notzero(b))
+	    pushv(a % b);
+	break;
+    case PLUS:
+	pop2();
+	pushv(a + b);
+	break;
+    case MINUS:
+	pop2();
+	pushv(a - b);
+	break;
+    case SHLEFT:
+	pop2();
+	pushv(a << b);
+	break;
+    case SHRIGHT:
+	pop2();
+	pushv(a >> b);
+	break;
+    case LES:
+	pop2();
+	pushv((long)(a < b));
+	break;
+    case LEQ:
+	pop2();
+	pushv((long)(a <= b));
+	break;
+    case GRE:
+	pop2();
+	pushv((long)(a > b));
+	break;
+    case GEQ:
+	pop2();
+	pushv((long)(a >= b));
+	break;
+    case DEQ:
+	pop2();
+	pushv((long)(a == b));
+	break;
+    case NEQ:
+	pop2();
+	pushv((long)(a != b));
+	break;
+    case DAND:
+	pop2();
+	pushv((long)(a && b));
+	break;
+    case DOR:
+	pop2();
+	pushv((long)(a || b));
+	break;
+    case DXOR:
+	pop2();
+	pushv((long)((a && !b) || (!a && b)));
+	break;
+    case QUEST:
+	pop3();
+	pushv((a) ? b : c);
+	break;
+    case COLON:
+	break;
+    case EQ:
+	pop2();
+	lv = stack[sp + 1].lval;
+	set(b);
+	break;
+    case PLUSEQ:
+	pop2lv();
+	set(a + b);
+	break;
+    case MINUSEQ:
+	pop2lv();
+	set(a - b);
+	break;
+    case MULEQ:
+	pop2lv();
+	set(a * b);
+	break;
+    case DIVEQ:
+	pop2lv();
+	if (notzero(b))
+	    set(a / b);
+	break;
+    case MODEQ:
+	pop2lv();
+	if (notzero(b))
+	    set(a % b);
+	break;
+    case ANDEQ:
+	pop2lv();
+	set(a & b);
+	break;
+    case XOREQ:
+	pop2lv();
+	set(a ^ b);
+	break;
+    case OREQ:
+	pop2lv();
+	set(a | b);
+	break;
+    case SHLEFTEQ:
+	pop2lv();
+	set(a << b);
+	break;
+    case SHRIGHTEQ:
+	pop2lv();
+	set(a >> b);
+	break;
+    case DANDEQ:
+	pop2lv();
+	set((long)(a && b));
+	break;
+    case DOREQ:
+	pop2lv();
+	set((long)(a || b));
+	break;
+    case DXOREQ:
+	pop2lv();
+	set((long)((a && !b) || (!a && b)));
+	break;
+    case COMMA:
+	pop2();
+	pushv(b);
+	break;
+    case PREPLUS:
+	stack[sp].val = setvar(stack[sp].lval,
+			       stack[sp].val + 1);
+	break;
+    case PREMINUS:
+	stack[sp].val = setvar(stack[sp].lval,
+			       stack[sp].val - 1);
+	break;
+    case POWER:
+	pop2();
+	if (b < 0) {
+	    zerr("can't handle negative exponents", NULL, 0);
+	    return;
+	}
+	for (c = 1; b--; c *= a);
+	pushv(c);
+	break;
+    case POWEREQ:
+	pop2lv();
+	if (b < 0) {
+	    zerr("can't handle negative exponents", NULL, 0);
+	    return;
+	}
+	for (c = 1; b--; c *= a);
+	set(c);
+	break;
+    default:
+	zerr("out of integers", NULL, 0);
+	return;
+    }
+}
+
+
+/**/
+static void
+bop(int tk)
+{
+    switch (tk) {
+    case DAND:
+    case DANDEQ:
+	if (!stack[sp].val)
+	    noeval++;
+	break;
+    case DOR:
+    case DOREQ:
+	if (stack[sp].val)
+	    noeval++;
+	break;
+    };
+}
+
+
+/**/
+static long
+mathevall(char *s, int prek, char **ep)
+{
+    int t0;
+    int xlastbase, xnoeval, xunary, xlvc;
+    char *xptr;
+    long xyyval;
+    LV xyylval;
+    char **xlvals = 0;
+    int xsp;
+    struct mathvalue *xstack = 0;
+    long ret;
+
+    xlastbase = xnoeval = xunary = xlvc = xyyval = xyylval = xsp = 0;
+    xptr = NULL;
+    if (mlevel++) {
+	xlastbase = lastbase;
+	xnoeval = noeval;
+	xunary = unary;
+	xlvc = lvc;
+	xptr = ptr;
+	xyyval = yyval;
+	xyylval = yylval;
+	xlvals = lvals;
+
+	xsp = sp;
+	xstack = stack;
+    }
+    stack = (struct mathvalue *)zalloc(STACKSZ*sizeof(struct mathvalue));
+    lastbase = -1;
+    lvals = (char **)zcalloc(LVCOUNT*sizeof(char *));
+    lvc = 0;
+    ptr = s;
+    sp = -1;
+    unary = 1;
+    mathparse(prek);
+    *ep = ptr;
+    if (sp)
+	zerr("bad math expression: unbalanced stack", NULL, 0);
+    for (t0 = 0; t0 != lvc; t0++)
+	zsfree(lvals[t0]);
+
+    ret = stack[0].val;
+
+    zfree(lvals, LVCOUNT*sizeof(char *));
+    zfree(stack, STACKSZ*sizeof(struct mathvalue));
+    if (--mlevel) {
+	lastbase = xlastbase;
+	noeval = xnoeval;
+	unary = xunary;
+	lvc = xlvc;
+	ptr = xptr;
+	yyval = xyyval;
+	yylval = xyylval;
+	lvals = xlvals;
+
+	sp = xsp;
+	stack = xstack;
+    }
+    return ret;
+}
+
+
+/**/
+long
+matheval(char *s)
+{
+    char *junk;
+    long x;
+    int xmtok = mtok;
+
+    if (!*s)
+	return 0;
+    x = mathevall(s, TOPPREC, &junk);
+    mtok = xmtok;
+    if (*junk)
+	zerr("bad math expression: illegal character: %c", NULL, *junk);
+    return x;
+}
+
+
+/**/
+long
+mathevalarg(char *s, char **ss)
+{
+    long x;
+    int xmtok = mtok;
+
+    x = mathevall(s, ARGPREC, ss);
+    if (mtok == COMMA)
+	(*ss)--;
+    mtok = xmtok;
+    return x;
+}
+
+
+/* operator-precedence parse the string and execute */
+
+/**/
+static void
+mathparse(int pc)
+{
+    int q, otok, onoeval;
+
+    if (errflag)
+	return;
+    mtok = zzlex();
+    while (prec[mtok] <= pc) {
+	if (errflag)
+	    return;
+	switch (mtok) {
+	case NUM:
+	    push(yyval, -1);
+	    break;
+	case ID:
+	    push(getiparam(lvals[yylval]), yylval);
+	    break;
+	case CID:
+	    push(getcvar(yylval), yylval);
+	    break;
+	case M_INPAR:
+	    mathparse(TOPPREC);
+	    if (mtok != M_OUTPAR) {
+		if (!errflag)
+		    zerr("')' expected", NULL, 0);
+		return;
+	    }
+	    break;
+	case QUEST:
+	    q = stack[sp].val;
+
+	    if (!q)
+		noeval++;
+	    mathparse(prec[QUEST] - 1);
+	    if (!q)
+		noeval--;
+	    else
+		noeval++;
+	    mathparse(prec[QUEST]);
+	    if (q)
+		noeval--;
+	    op(QUEST);
+	    continue;
+	default:
+	    otok = mtok;
+	    onoeval = noeval;
+	    if (type[otok] == BOOL)
+		bop(otok);
+	    mathparse(prec[otok] - (type[otok] != RL));
+	    noeval = onoeval;
+	    op(otok);
+	    continue;
+	}
+	mtok = zzlex();
+    }
+}