cmd/re/sed1.c

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1995-2012 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                 Eclipse Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*          http://www.eclipse.org/org/documents/epl-v10.html           *
*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                                                                      *
***********************************************************************/
#pragma prototyped

#include "sed.h"

#include <ctype.h>

#define ustrlen(p) strlen((char*)(p))
#define ustrcmp(p, q) strcmp((char*)(p), (char*)(q))
#define ustrcpy(p, q) (unsigned char*)strcpy((char*)(p), (char*)(q))
#define ustrchr(p, c) (unsigned char*)strchr((char*)(p), c)

int blank(Text*);
void fixlabels(Text*);
void fixbrack(Text*);
void ckludge(Text*, int, int, int, Text*);
int addr(Text*, Text*);
word* instr(unsigned char*);
unsigned char *succi(unsigned char*);

#if DEBUG
extern void regdump(regex_t*);  /* secret entry into regex pkg */
#endif

static Text rebuf;

static const unsigned char adrs[UCHAR_MAX+1] = {    /* max no. of addrs, 3 is illegal */
    0, 3, 3, 3, 3, 3, 3, 3, 3, 3, 0, 3, 3, 3, 3, 3, /* <nl> */
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
    3, 2, 3, 0, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* !# */
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 0, 0, 3, 1, 3, 3, /* := */
    3, 3, 3, 3, 2, 3, 3, 2, 2, 3, 3, 3, 3, 3, 2, 3, /* DGHN */
    2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* P */
    3, 1, 2, 2, 2, 3, 3, 2, 2, 1, 3, 3, 2, 3, 2, 3, /* a-n */
    2, 1, 2, 2, 2, 3, 3, 2, 2, 2, 3, 2, 3, 0, 3, 3, /* p-y{} */
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3
};

#define Ec Tc   /* commands that have same compilation method */
#define Dc Tc
#define Gc Tc
#define Hc Tc
#define Nc Tc
#define Pc Tc
#define dc Tc
#define gc Tc
#define hc Tc
#define lc Tc
#define nc Tc
#define pc Tc
#define xc Tc
#define tc bc
#define ic ac
#define cc ac

unsigned char *synl;    /* current line pointer for syntax errors */

/* COMMAND LAYOUT */

int
blank(Text *t)
{
    if(*t->w==' ' || *t->w=='\t' || *t->w=='\r') {
        t->w++;
        return 1;
    } else
        return 0;
}

word *
instr(unsigned char *p)     /* get address of command word */
{
    word *q = (word*)p;
    while((*q & IMASK) != IMASK)
        q++;
    return q;
}

unsigned char *
succi(unsigned char *p)
{
    word *q = instr(p);
    if(code(*q) == '{')
        return (unsigned char*)(q+1);
    else
        return p + (*q & LMASK);
}

word
pack(int neg, int cmd, word length)
{
    int l = length & LMASK;
    if(length != l)
        syntax("<command-list> or <text> too long");
    return IMASK | neg | cmd << 2*BYTE | l;
}

void
putword(Text *s, word n)
{
    assure(s, sizeof(word));
    *(word*)s->w = n;
    s->w += sizeof(word);
}

int
number(Text *t)
{
    unsigned n = 0;
    while(isdigit(*t->w)) {
        if(n > (INT_MAX-9)/10)
            syntax("number too big");
        n = n*10 + *t->w++ - '0';
    }
    return n;
}

int
addr(Text *script, Text *t)
{
    word n;
    if(reflags & REG_LENIENT)
        while(*t->w == ' ' || *t->w == '\t' || *t->w == '\r')
            t->w++;
    switch(*t->w) {
    default:
        return 0;
    case '$':
        t->w++;
        n = DOLLAR;
        break;
    case '\\':
        t->w++;
    case '/':
        n = recomp(&rebuf, t, 0) | REGADR;
        break;
    case '0': case '1': case '2': case '3': case '4':
    case '5': case '6': case '7': case '8': case '9':
        n = number(t);
        if(n == 0)
            syntax("address is zero");
    }
    putword(script, n);
    if(reflags & REG_LENIENT)
        while(*t->w == ' ' || *t->w == '\t' || *t->w == '\r')
            t->w++;
    return 1;
}

regex_t *
readdr(word x)
{
    return (regex_t*)(rebuf.s + (x&AMASK));
}

/* LABEL HANDLING */

/* the labels array consists of int values followed by strings.
   value -1 means unassigned; other values are relative to the
   beginning of the script

   on the first pass, every script ref to a label becomes the
   integer offset of that label in the labels array, or -1 if
   it is a branch to the end of script

   on the second pass (fixlabels), the script ref is replaced
   by the value from the labels array. */

Text labels;

word *
lablook(unsigned char *l, Text *labels)
{
    unsigned char *p, *q;
    word n, m;
    assure(labels, 1);
    for(p = labels->s; p < labels->w; ) {
        q = p + sizeof(word);
        if(ustrcmp(q, l) == 0)
            return (word*)p;
        q += ustrlen(q) + 1;
        p = (unsigned char*)wordp(q);
    }
    n = ustrlen(l);
    m = (p - labels->s);
    assure(labels, sizeof(word)+n+1+sizeof(word));
    p = labels->s + m;
    *(word*)p = -1;
    q = p + sizeof(word);
    ustrcpy(q, l);
    q += ustrlen(q) + 1;
    labels->w = (unsigned char*)wordp(q);
    return (word*)p;
}

/* find pos in label list; assign value i to label if i>=0 */

word
getlab(Text *t, word i)
{
    word *p;
    unsigned char *u;
    while(blank(t));    /* not exactly posix */
    for(u=t->w; *t->w!='\n'; t->w++)
        if(!isprint(*t->w) || *t->w==' ' || *t->w=='\t' || *t->w=='\r')
            synwarn("invisible character in name");
    if(u == t->w)
        return -1;
    *t->w = 0;
    p = lablook(u, &labels);
    if(*p == -1)
        *p = i;
    else if(i != -1)
        syntax("duplicate label");
    *t->w = '\n';
    return (unsigned char*)p - labels.s;
}

void
Cc(Text *script, Text *t)   /* colon */
{
    if(getlab(t, script->w - sizeof(word) - script->s) == -1)
        syntax("missing label");
}

void
bc(Text *script, Text *t)
{
    word g;
    g = getlab(t, -1);  /* relative pointer to label list */
    putword(script, g);
}

void
fixlabels(Text *script)
{
    unsigned char *p;
    word *q;
    for(p=script->s; p<script->w; p=succi(p)) {
        q = instr(p);
        switch(code(*q)) {
        case 't':
        case 'b':
            if(q[1] == -1)
                q[1] = script->w - script->s;
            else if(*(word*)(labels.s+q[1]) != -1)
                q[1] = *(word*)(labels.s+q[1]);
            else
                error(3, "undefined label: %s",
                    labels.s+q[1]+sizeof(word));
        }
    }
    free(labels.s);
}

/* FILES */

Text files;

void
rc(Text *script, Text *t)
{
    unsigned char *u;
    if(!blank(t))
        synwarn("no space before file name");
    while(blank(t)) ;
    for(u=t->w; *t->w!='\n'; t->w++) ;
    if(u == t->w)
        syntax("missing file name");
    *t->w = 0;
    putword(script, (unsigned char*)lablook(u, &files) - files.s);
    *t->w = '\n';
}

void
wc(Text *script, Text *t)
{
    word *p;
    rc(script, t);
    p = (word*)(files.s + ((word*)script->w)[-1]);
    if(*p != -1)
        return;
    *(Sfio_t**)p = sfopen(NiL, (char*)(p+1), "w");
    if(*(Sfio_t**)p == 0)
        syntax("can't open file for writing");
}

/* BRACKETS */

Text brack;

/* Lc() stacks (in brack) the location of the { command word.
   Rc() stuffs into that word the offset of the } sequel
   relative to the command word.
   fixbrack() modifies the offset to be relative to the
   beginning of the instruction, including addresses. */

void                /* { */
Lc(Text *script, Text *t)
{
    while(blank(t));
    putword(&brack, script->w - sizeof(word) - script->s);
}

void                /* } */
Rc(Text *script, Text *t)
{
    word l;
    word *p;
    t = t;
    if(brack.w == 0 || (brack.w-=sizeof(word)) < brack.s)
        syntax("unmatched }");
    l = *(word*)brack.w;
    p = (word*)(script->s + l);
    l = script->w - script->s - l;
    if(l >= LMASK - 3*sizeof(word)) /* fixbrack could add 3 */
        syntax("{command-list} too long)");
    *p = (*p&~LMASK) | l;
}

void
fixbrack(Text *script)
{
    unsigned char *p;
    word *q;
    if(brack.w == 0)
        return;
    if(brack.w > brack.s)
        syntax("unmatched {");
    for(p=script->s; p<script->w; p=succi(p)) {
        q = instr(p);
        if(code(*q) == '{')
            *q += (unsigned char*)q - p;
    }
    free(brack.s);
}

/* EASY COMMANDS */

void
Xc(Text *script, Text *t)   /* # */
{
    script = script;    /* avoid use/set diagnostics */
    if(t->s[1]=='n')
        nflag = 1;
    while(*t->w != '\n')
        t->w++;
}

void
Ic(Text *script, Text *t)   /* ignore */
{
    script = script;
    t->w--;
}

void
Tc(Text *script, Text *t)   /* trivial to compile */
{
    script = script;
    t = t;
}

void
xx(Text *script, Text *t)
{
    script = script;
    t = t;
    syntax("unknown command");
}

/* MISCELLANY */

void
ac(Text *script, Text *t)
{
    if(*t->w++ != '\\' || *t->w++ != '\n')
        syntax("\\<newline> missing after command");
    for(;;) {
        while(bflag && blank(t)) ;
        assure(script, 2 + sizeof(word));
        switch(*t->w) {
        case 0:
            error(ERROR_PANIC|4, "bug: missed end of <text>");
        case '\n':
            *script->w++ = *t->w;
            *script->w++ = 0;
            script->w = (unsigned char*)wordp(script->w);
            return;
        case '\\':
            t->w++;
        default:
            *script->w++ = *t->w++;
        }
    }
}

void
qc(Text *script, Text *t)
{
    sfset(sfstdin, SF_SHARE, 1);
    script = script;
    t = t;
}

void
sc(Text *script, Text *t)
{
    regex_t* re;
    word n;
    int c;
    n = recomp(&rebuf, t, 1);
    putword(script, n);
    re = readdr(n);
    if(c = regsubcomp(re, (char*)t->w, NiL, 0, 0))
        badre(re, c);
    t->w += re->re_npat;
    script->w = (unsigned char*)wordp(script->w);
    if(re->re_sub->re_flags & REG_SUB_WRITE)
        wc(script, t);
}

void
yc(Text *script, Text *t)
{
    word i, m, x;
    int delim;
    unsigned char *s, *pb, *qb;
    unsigned char *p, *q, *o, *v, **w;
    int pc, qc;
    m = 0;
    if(mbwide()) {
        pb = t->w;
        if((delim = mbchar(pb)) == '\n' || delim=='\\')
            syntax("missing delimiter");
        p = pb;
        while((o=p),(pc = mbchar(p))!=delim) {
            if(pc=='\n')
                syntax("missing delimiter");
            if(pc=='\\') {
                o = p;
                pc = mbchar(p);
            }
            if((p-o)>1 && pc>m)
                m = pc;
        }
    }
    if(m) {
        x = 0;
        qb = p;
        while((o=p), (pc = mbchar(p))!=delim) {
            if(pc=='\\') {
                o = p;
                pc = mbchar(p);
            }
            x += (p-o)+1;
        }
        x = roundof(x, sizeof(word));
        m++;
        assure(script, (m+1)*sizeof(unsigned char*)+x);
        w = (unsigned char**)script->w;
        *w++ = (unsigned char*)0 + m;
        script->w += (m+1)*sizeof(unsigned char*);
        v = (unsigned char*)script->w;
        script->w += x;
        for(i=0; i<m; i++)
            w[i] = 0;
        p = pb;
        q = qb;
        while((pb=p), (pc = mbchar(p))!=delim) {
            if(pc=='\\') {
                pb = p;
                if((qc = mbchar(p))=='n')
                    pc = '\n';
                else if(qc==delim || qc=='\\')
                    pc = qc;
                else
                    p = pb-1;
            }
            qb = q;
            if((qc = mbchar(q)) == '\n')
                syntax("missing delimiter");
            if(qc==delim)
                syntax("string lengths differ");
            if(qc=='\\') {
                qb = q;
                if((qc = mbchar(q))=='n')
                    *qb = '\n';
                else if(qc!=delim && qc!='\\')
                    q = qb-1;
            }
            i = (q-qb);
            if(w[pc]) {
                if(w[pc][0]!=i || memcmp(&w[pc][1], qb, i))
                    syntax("ambiguous map");
                synwarn("redundant map");
            }
            else {
                w[pc] = v;
                *v++ = (unsigned char)i;
                memcpy(v, qb, i);
                v += i;
            }
        }
        if(mbchar(q) != delim)
            syntax("string lengths differ");
    }
    else {
        if((delim = *t->w++) == '\n' || delim=='\\')
            syntax("missing delimiter");
        assure(script, sizeof(unsigned char*)+UCHAR_MAX+1);
        w = (unsigned char**)script->w;
        *w++ = 0;
        s = (unsigned char*)w;
        script->w += sizeof(unsigned char*)+UCHAR_MAX+1;
        for(i=0; i<UCHAR_MAX+1; i++)
            s[i] = 0;
        for(q=t->w; (qc = *q++)!=delim; ) {
            if(qc == '\n')
                syntax("missing delimiter");
            if(qc=='\\' && *q==delim)
                q++;
        }
        for(p=t->w; (pc = *p++) != delim; ) {
            if(pc=='\\') {
                if(*p==delim || *p=='\\')
                    pc = *p++;
                else if(*p=='n') {
                    p++;
                    pc = '\n';
                }
            }
            if((qc = *q++) == '\n')
                syntax("missing delimiter");
            if(qc==delim)
                syntax("string lengths differ");
            if(qc=='\\') {
                if(*q==delim || *q=='\\')
                    qc = *q++;
                else if(*q=='n') {
                    q++;
                    qc = '\n';
                }
            }
            if(s[pc]) {
                if(s[pc]!=qc)
                    syntax("ambiguous map");
                synwarn("redundant map");
            }
            s[pc] = qc;
        }
        if(*q++ != delim)
            syntax("string lengths differ");
        for(i=0; i<UCHAR_MAX+1; i++)
            if(s[i] == 0)
                s[i] = (unsigned char)i;
    }
    t->w = q;
}

void
synwarn(char *s)
{
    unsigned char *t = ustrchr(synl, '\n');
    error(1, "%s: %.*s", s, t-synl, synl);
}

void
syntax(char *s)
{
    unsigned char *t = ustrchr(synl, '\n');
    error(3, "%s: %.*s", s, t-synl, synl);
}

void
badre(regex_t* re, int code)
{
    unsigned char *t = ustrchr(synl, '\n');
    if(code && code!= REG_NOMATCH) {
        char buf[UCHAR_MAX+1];
        regerror(code, re, buf, sizeof(buf));
        error(3, "%s: %.*s", buf, t-synl, synl);
    }
    else
        error(3, "invalid regular expression: %.*s", t-synl, synl);
}

#if DEBUG

void
printscript(Text *script)
{
    unsigned char *s;
    word *q;
    for(s=script->s; s<script->w; s = succi(s)) {
        q = (word*)s;
        if((*q&IMASK) != IMASK) {
            if((*q&REGADR) == 0)
                printf("%d", *q);
            else
                regdump((regex_t*)(*q & AMASK));
            q++;
        }
        if((*q&IMASK) != IMASK) {
            if((*q&REGADR) == 0)
                printf(",%d", *q);
            else
                regdump((regex_t*)(*q & AMASK));
            q += 2;
        }
        if(code(*q) == '\n')
            continue;
        printf("%s%c\n", *q&NEG?"!":"", code(*q));
    }
}

#endif

#if DEBUG & 2

/* debugging code 2; execute stub.
   prints the compiled script (without arguments)
   then each input line with line numbers */

void
execute(Text *script, Text *y)
{
    if(recno == 1)
        printscript(script);
    printf("%d:%s",recno,y->s);
}

#endif

typedef void (*cmdf)(Text*, Text*);

static const cmdf docom[128] = {
    xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,Ic,xx,xx,xx,xx,xx, /* <nl> */
    xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,
    xx,Ic,xx,Xc,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx, /* !# */
    xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,Cc,Ic,xx,Ec,xx,xx, /* :;= */
    xx,xx,xx,xx,Dc,xx,xx,Gc,Hc,xx,xx,xx,xx,xx,Nc,xx, /* DGHN */
    Pc,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx, /* P */
    xx,ac,bc,cc,dc,xx,xx,gc,hc,ic,xx,xx,lc,xx,nc,xx, /* a-n */
    pc,qc,rc,sc,tc,xx,xx,wc,xc,yc,xx,Lc,xx,Rc,xx,xx  /* p-y{} */
};

void
compile(Text *script, Text *t)
{
    word loc;   /* progam counter */
    int neg;    /* ! in effect */
    int cmd;
    int naddr;
    word *q;    /* address of instruction word */
    t->w = t->s;    /* here w is a read pointer */
    while(*t->w) {
        assure(script, 4*sizeof(word));
        loc = script->w - script->s;
        synl = t->w;
        naddr = 0;
        while(blank(t)) ;
        naddr += addr(script, t);
        if(naddr && *t->w ==',') {
            t->w++;
            naddr += addr(script, t);
            if(naddr < 2)
                syntax("missing address");
        }
        q = (word*)script->w;
        if(naddr == 2)
            *q++ = INACT;
        script->w = (unsigned char*)(q+1);
        neg = 0;
        for(;;) {
            while(blank(t));
            cmd = *t->w++;
            if(neg && docom[ccmapchr(map,cmd)&0x7f]==Ic)
                syntax("improper !");
            if(cmd != '!')
                break;
            neg = NEG;
        }
        if(!neg) {
            switch(adrs[ccmapchr(map,cmd)]) {
            case 1:
                if(naddr <= 1)
                    break;
            case 0:
                if(naddr == 0)
                    break;
                syntax("too many addresses");
            }
        }
        (*docom[ccmapchr(map,cmd)&0x7f])(script, t);
        while(*t->w == ' ' || *t->w == '\t' || *t->w == '\r')
            t->w++;
        switch(*t->w) {
        case 0:
            script->w = script->s + loc;
            break;
        case ';':
        case '\n':
            t->w++;
            break;
        default:
            if(cmd == '{')
                break;
            syntax("junk after command");
        }
        *q = pack(neg,cmd,script->w-script->s-loc);
    }
    fixbrack(script);
    fixlabels(script);
}