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| -rw-r--r-- | src/parser.c | 1608 |
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diff --git a/src/parser.c b/src/parser.c new file mode 100644 index 0000000..35a0351 --- /dev/null +++ b/src/parser.c @@ -0,0 +1,1608 @@ +/* $NetBSD: parser.c,v 1.54 2002/11/24 22:35:42 christos Exp $ */ + +/*- + * Copyright (c) 1991, 1993 + * 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. 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. + */ + +#include <sys/cdefs.h> +#ifndef lint +#if 0 +static char sccsid[] = "@(#)parser.c 8.7 (Berkeley) 5/16/95"; +#else +__RCSID("$NetBSD: parser.c,v 1.54 2002/11/24 22:35:42 christos Exp $"); +#endif +#endif /* not lint */ + +#include <stdlib.h> + +#include "shell.h" +#include "parser.h" +#include "nodes.h" +#include "expand.h" /* defines rmescapes() */ +#include "eval.h" /* defines commandname */ +#include "redir.h" /* defines copyfd() */ +#include "exec.h" /* defines find_builtin() */ +#include "syntax.h" +#include "options.h" +#include "input.h" +#include "output.h" +#include "var.h" +#include "error.h" +#include "memalloc.h" +#include "mystring.h" +#include "alias.h" +#include "show.h" +#include "builtins.h" +#ifndef SMALL +#include "myhistedit.h" +#endif + +/* + * Shell command parser. + */ + +#define EOFMARKLEN 79 + +/* values returned by readtoken */ +#include "token.h" + + + +struct heredoc { + struct heredoc *next; /* next here document in list */ + union node *here; /* redirection node */ + char *eofmark; /* string indicating end of input */ + int striptabs; /* if set, strip leading tabs */ +}; + + + +struct heredoc *heredoclist; /* list of here documents to read */ +int parsebackquote; /* nonzero if we are inside backquotes */ +int doprompt; /* if set, prompt the user */ +int needprompt; /* true if interactive and at start of line */ +int lasttoken; /* last token read */ +MKINIT int tokpushback; /* last token pushed back */ +char *wordtext; /* text of last word returned by readtoken */ +int checkkwd; +struct nodelist *backquotelist; +union node *redirnode; +struct heredoc *heredoc; +int quoteflag; /* set if (part of) last token was quoted */ +int startlinno; /* line # where last token started */ + + +STATIC union node *list(int); +STATIC union node *andor(void); +STATIC union node *pipeline(void); +STATIC union node *command(void); +STATIC union node *simplecmd(void); +STATIC union node *makename(void); +STATIC void parsefname(void); +STATIC void parseheredoc(void); +STATIC int peektoken(void); +STATIC int readtoken(void); +STATIC int xxreadtoken(void); +STATIC int readtoken1(int, char const *, char *, int); +STATIC int noexpand(char *); +STATIC void synexpect(int) __attribute__((__noreturn__)); +STATIC void synerror(const char *) __attribute__((__noreturn__)); +STATIC void setprompt(int); + + +static inline int +isassignment(const char *p) +{ + const char *q = endofname(p); + if (p == q) + return 0; + return *q == '='; +} + + +/* + * Read and parse a command. Returns NEOF on end of file. (NULL is a + * valid parse tree indicating a blank line.) + */ + +union node * +parsecmd(int interact) +{ + int t; + + tokpushback = 0; + doprompt = interact; + if (doprompt) + setprompt(doprompt); + needprompt = 0; + t = readtoken(); + if (t == TEOF) + return NEOF; + if (t == TNL) + return NULL; + tokpushback++; + return list(1); +} + + +STATIC union node * +list(int nlflag) +{ + union node *n1, *n2, *n3; + int tok; + + checkkwd = CHKNL | CHKKWD | CHKALIAS; + if (nlflag == 2 && tokendlist[peektoken()]) + return NULL; + n1 = NULL; + for (;;) { + n2 = andor(); + tok = readtoken(); + if (tok == TBACKGND) { + if (n2->type == NPIPE) { + n2->npipe.backgnd = 1; + } else { + if (n2->type != NREDIR) { + n3 = stalloc(sizeof(struct nredir)); + n3->nredir.n = n2; + n3->nredir.redirect = NULL; + n2 = n3; + } + n2->type = NBACKGND; + } + } + if (n1 == NULL) { + n1 = n2; + } + else { + n3 = (union node *)stalloc(sizeof (struct nbinary)); + n3->type = NSEMI; + n3->nbinary.ch1 = n1; + n3->nbinary.ch2 = n2; + n1 = n3; + } + switch (tok) { + case TBACKGND: + case TSEMI: + tok = readtoken(); + /* fall through */ + case TNL: + if (tok == TNL) { + parseheredoc(); + if (nlflag == 1) + return n1; + } else { + tokpushback++; + } + checkkwd = CHKNL | CHKKWD | CHKALIAS; + if (tokendlist[peektoken()]) + return n1; + break; + case TEOF: + if (heredoclist) + parseheredoc(); + else + pungetc(); /* push back EOF on input */ + return n1; + default: + if (nlflag == 1) + synexpect(-1); + tokpushback++; + return n1; + } + } +} + + + +STATIC union node * +andor(void) +{ + union node *n1, *n2, *n3; + int t; + + n1 = pipeline(); + for (;;) { + if ((t = readtoken()) == TAND) { + t = NAND; + } else if (t == TOR) { + t = NOR; + } else { + tokpushback++; + return n1; + } + checkkwd = CHKNL | CHKKWD | CHKALIAS; + n2 = pipeline(); + n3 = (union node *)stalloc(sizeof (struct nbinary)); + n3->type = t; + n3->nbinary.ch1 = n1; + n3->nbinary.ch2 = n2; + n1 = n3; + } +} + + + +STATIC union node * +pipeline(void) +{ + union node *n1, *n2, *pipenode; + struct nodelist *lp, *prev; + int negate; + + negate = 0; + TRACE(("pipeline: entered\n")); + if (readtoken() == TNOT) { + negate = !negate; + checkkwd = CHKKWD | CHKALIAS; + } else + tokpushback++; + n1 = command(); + if (readtoken() == TPIPE) { + pipenode = (union node *)stalloc(sizeof (struct npipe)); + pipenode->type = NPIPE; + pipenode->npipe.backgnd = 0; + lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); + pipenode->npipe.cmdlist = lp; + lp->n = n1; + do { + prev = lp; + lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); + checkkwd = CHKNL | CHKKWD | CHKALIAS; + lp->n = command(); + prev->next = lp; + } while (readtoken() == TPIPE); + lp->next = NULL; + n1 = pipenode; + } + tokpushback++; + if (negate) { + n2 = (union node *)stalloc(sizeof (struct nnot)); + n2->type = NNOT; + n2->nnot.com = n1; + return n2; + } else + return n1; +} + + + +STATIC union node * +command(void) +{ + union node *n1, *n2; + union node *ap, **app; + union node *cp, **cpp; + union node *redir, **rpp; + union node **rpp2; + int t; + + redir = NULL; + rpp2 = &redir; + + switch (readtoken()) { + default: + synexpect(-1); + /* NOTREACHED */ + case TIF: + n1 = (union node *)stalloc(sizeof (struct nif)); + n1->type = NIF; + n1->nif.test = list(0); + if (readtoken() != TTHEN) + synexpect(TTHEN); + n1->nif.ifpart = list(0); + n2 = n1; + while (readtoken() == TELIF) { + n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); + n2 = n2->nif.elsepart; + n2->type = NIF; + n2->nif.test = list(0); + if (readtoken() != TTHEN) + synexpect(TTHEN); + n2->nif.ifpart = list(0); + } + if (lasttoken == TELSE) + n2->nif.elsepart = list(0); + else { + n2->nif.elsepart = NULL; + tokpushback++; + } + t = TFI; + break; + case TWHILE: + case TUNTIL: { + int got; + n1 = (union node *)stalloc(sizeof (struct nbinary)); + n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL; + n1->nbinary.ch1 = list(0); + if ((got=readtoken()) != TDO) { +TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : "")); + synexpect(TDO); + } + n1->nbinary.ch2 = list(0); + t = TDONE; + break; + } + case TFOR: + if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) + synerror("Bad for loop variable"); + n1 = (union node *)stalloc(sizeof (struct nfor)); + n1->type = NFOR; + n1->nfor.var = wordtext; + checkkwd = CHKKWD | CHKALIAS; + if (readtoken() == TIN) { + app = ≈ + while (readtoken() == TWORD) { + n2 = (union node *)stalloc(sizeof (struct narg)); + n2->type = NARG; + n2->narg.text = wordtext; + n2->narg.backquote = backquotelist; + *app = n2; + app = &n2->narg.next; + } + *app = NULL; + n1->nfor.args = ap; + if (lasttoken != TNL && lasttoken != TSEMI) + synexpect(-1); + } else { + n2 = (union node *)stalloc(sizeof (struct narg)); + n2->type = NARG; + n2->narg.text = (char *)dolatstr; + n2->narg.backquote = NULL; + n2->narg.next = NULL; + n1->nfor.args = n2; + /* + * Newline or semicolon here is optional (but note + * that the original Bourne shell only allowed NL). + */ + if (lasttoken != TNL && lasttoken != TSEMI) + tokpushback++; + } + checkkwd = CHKNL | CHKKWD | CHKALIAS; + if (readtoken() != TDO) + synexpect(TDO); + n1->nfor.body = list(0); + t = TDONE; + break; + case TCASE: + n1 = (union node *)stalloc(sizeof (struct ncase)); + n1->type = NCASE; + if (readtoken() != TWORD) + synexpect(TWORD); + n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg)); + n2->type = NARG; + n2->narg.text = wordtext; + n2->narg.backquote = backquotelist; + n2->narg.next = NULL; + do { + checkkwd = CHKKWD | CHKALIAS; + } while (readtoken() == TNL); + if (lasttoken != TIN) + synexpect(TIN); + cpp = &n1->ncase.cases; +next_case: + checkkwd = CHKNL | CHKKWD; + t = readtoken(); + while(t != TESAC) { + if (lasttoken == TLP) + readtoken(); + *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); + cp->type = NCLIST; + app = &cp->nclist.pattern; + for (;;) { + *app = ap = (union node *)stalloc(sizeof (struct narg)); + ap->type = NARG; + ap->narg.text = wordtext; + ap->narg.backquote = backquotelist; + if (readtoken() != TPIPE) + break; + app = &ap->narg.next; + readtoken(); + } + ap->narg.next = NULL; + if (lasttoken != TRP) + synexpect(TRP); + cp->nclist.body = list(2); + + cpp = &cp->nclist.next; + + checkkwd = CHKNL | CHKKWD; + if ((t = readtoken()) != TESAC) { + if (t != TENDCASE) + synexpect(TENDCASE); + else + goto next_case; + } + } + *cpp = NULL; + goto redir; + case TLP: + n1 = (union node *)stalloc(sizeof (struct nredir)); + n1->type = NSUBSHELL; + n1->nredir.n = list(0); + n1->nredir.redirect = NULL; + t = TRP; + break; + case TBEGIN: + n1 = list(0); + t = TEND; + break; + case TWORD: + case TREDIR: + tokpushback++; + return simplecmd(); + } + + if (readtoken() != t) + synexpect(t); + +redir: + /* Now check for redirection which may follow command */ + checkkwd = CHKKWD | CHKALIAS; + rpp = rpp2; + while (readtoken() == TREDIR) { + *rpp = n2 = redirnode; + rpp = &n2->nfile.next; + parsefname(); + } + tokpushback++; + *rpp = NULL; + if (redir) { + if (n1->type != NSUBSHELL) { + n2 = (union node *)stalloc(sizeof (struct nredir)); + n2->type = NREDIR; + n2->nredir.n = n1; + n1 = n2; + } + n1->nredir.redirect = redir; + } + + return n1; +} + + +STATIC union node * +simplecmd(void) { + union node *args, **app; + union node *n = NULL; + union node *vars, **vpp; + union node **rpp, *redir; + int savecheckkwd; + + args = NULL; + app = &args; + vars = NULL; + vpp = &vars; + redir = NULL; + rpp = &redir; + + savecheckkwd = CHKALIAS; + for (;;) { + checkkwd = savecheckkwd; + switch (readtoken()) { + case TWORD: + n = (union node *)stalloc(sizeof (struct narg)); + n->type = NARG; + n->narg.text = wordtext; + n->narg.backquote = backquotelist; + if (savecheckkwd && isassignment(wordtext)) { + *vpp = n; + vpp = &n->narg.next; + } else { + *app = n; + app = &n->narg.next; + savecheckkwd = 0; + } + break; + case TREDIR: + *rpp = n = redirnode; + rpp = &n->nfile.next; + parsefname(); /* read name of redirection file */ + break; + case TLP: + if ( + args && app == &args->narg.next && + !vars && !redir + ) { + struct builtincmd *bcmd; + const char *name; + + /* We have a function */ + if (readtoken() != TRP) + synexpect(TRP); + name = n->narg.text; + if ( + !goodname(name) || ( + (bcmd = find_builtin(name)) && + bcmd->flags & BUILTIN_SPECIAL + ) + ) + synerror("Bad function name"); + n->type = NDEFUN; + checkkwd = CHKNL | CHKKWD | CHKALIAS; + n->narg.next = command(); + return n; + } + /* fall through */ + default: + tokpushback++; + goto out; + } + } +out: + *app = NULL; + *vpp = NULL; + *rpp = NULL; + n = (union node *)stalloc(sizeof (struct ncmd)); + n->type = NCMD; + n->ncmd.args = args; + n->ncmd.assign = vars; + n->ncmd.redirect = redir; + return n; +} + +STATIC union node * +makename(void) +{ + union node *n; + + n = (union node *)stalloc(sizeof (struct narg)); + n->type = NARG; + n->narg.next = NULL; + n->narg.text = wordtext; + n->narg.backquote = backquotelist; + return n; +} + +void fixredir(union node *n, const char *text, int err) + { + TRACE(("Fix redir %s %d\n", text, err)); + if (!err) + n->ndup.vname = NULL; + + if (is_digit(text[0]) && text[1] == '\0') + n->ndup.dupfd = digit_val(text[0]); + else if (text[0] == '-' && text[1] == '\0') + n->ndup.dupfd = -1; + else { + + if (err) + synerror("Bad fd number"); + else + n->ndup.vname = makename(); + } +} + + +STATIC void +parsefname(void) +{ + union node *n = redirnode; + + if (readtoken() != TWORD) + synexpect(-1); + if (n->type == NHERE) { + struct heredoc *here = heredoc; + struct heredoc *p; + int i; + + if (quoteflag == 0) + n->type = NXHERE; + TRACE(("Here document %d\n", n->type)); + if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) + synerror("Illegal eof marker for << redirection"); + rmescapes(wordtext); + here->eofmark = wordtext; + here->next = NULL; + if (heredoclist == NULL) + heredoclist = here; + else { + for (p = heredoclist ; p->next ; p = p->next); + p->next = here; + } + } else if (n->type == NTOFD || n->type == NFROMFD) { + fixredir(n, wordtext, 0); + } else { + n->nfile.fname = makename(); + } +} + + +/* + * Input any here documents. + */ + +STATIC void +parseheredoc(void) +{ + struct heredoc *here; + union node *n; + + here = heredoclist; + heredoclist = 0; + + while (here) { + if (needprompt) { + setprompt(2); + } + readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, + here->eofmark, here->striptabs); + n = (union node *)stalloc(sizeof (struct narg)); + n->narg.type = NARG; + n->narg.next = NULL; + n->narg.text = wordtext; + n->narg.backquote = backquotelist; + here->here->nhere.doc = n; + here = here->next; + } +} + +STATIC int +peektoken(void) +{ + int t; + + t = readtoken(); + tokpushback++; + return (t); +} + +STATIC int +readtoken(void) +{ + int t; +#ifdef DEBUG + int alreadyseen = tokpushback; +#endif + +top: + t = xxreadtoken(); + + /* + * eat newlines + */ + if (checkkwd & CHKNL) { + while (t == TNL) { + parseheredoc(); + t = xxreadtoken(); + } + } + + if (t != TWORD || quoteflag) { + goto out; + } + + /* + * check for keywords + */ + if (checkkwd & CHKKWD) { + const char *const *pp; + + if ((pp = findkwd(wordtext))) { + lasttoken = t = pp - parsekwd + KWDOFFSET; + TRACE(("keyword %s recognized\n", tokname[t])); + goto out; + } + } + + if (checkkwd & CHKALIAS) { + struct alias *ap; + if ((ap = lookupalias(wordtext, 1)) != NULL) { + if (*ap->val) { + pushstring(ap->val, ap); + } + goto top; + } + } +out: + checkkwd = 0; +#ifdef DEBUG + if (!alreadyseen) + TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); + else + TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); +#endif + return (t); +} + + +/* + * Read the next input token. + * If the token is a word, we set backquotelist to the list of cmds in + * backquotes. We set quoteflag to true if any part of the word was + * quoted. + * If the token is TREDIR, then we set redirnode to a structure containing + * the redirection. + * In all cases, the variable startlinno is set to the number of the line + * on which the token starts. + * + * [Change comment: here documents and internal procedures] + * [Readtoken shouldn't have any arguments. Perhaps we should make the + * word parsing code into a separate routine. In this case, readtoken + * doesn't need to have any internal procedures, but parseword does. + * We could also make parseoperator in essence the main routine, and + * have parseword (readtoken1?) handle both words and redirection.] + */ + +#define RETURN(token) return lasttoken = token + +STATIC int +xxreadtoken(void) +{ + int c; + + if (tokpushback) { + tokpushback = 0; + return lasttoken; + } + if (needprompt) { + setprompt(2); + } + startlinno = plinno; + for (;;) { /* until token or start of word found */ + c = pgetc_macro(); + switch (c) { + case ' ': case '\t': + case PEOA: + continue; + case '#': + while ((c = pgetc()) != '\n' && c != PEOF); + pungetc(); + continue; + case '\\': + if (pgetc() == '\n') { + startlinno = ++plinno; + if (doprompt) + setprompt(2); + continue; + } + pungetc(); + goto breakloop; + case '\n': + plinno++; + needprompt = doprompt; + RETURN(TNL); + case PEOF: + RETURN(TEOF); + case '&': + if (pgetc() == '&') + RETURN(TAND); + pungetc(); + RETURN(TBACKGND); + case '|': + if (pgetc() == '|') + RETURN(TOR); + pungetc(); + RETURN(TPIPE); + case ';': + if (pgetc() == ';') + RETURN(TENDCASE); + pungetc(); + RETURN(TSEMI); + case '(': + RETURN(TLP); + case ')': + RETURN(TRP); + default: + goto breakloop; + } + } +breakloop: + return readtoken1(c, BASESYNTAX, (char *)NULL, 0); +#undef RETURN +} + + + +/* + * If eofmark is NULL, read a word or a redirection symbol. If eofmark + * is not NULL, read a here document. In the latter case, eofmark is the + * word which marks the end of the document and striptabs is true if + * leading tabs should be stripped from the document. The argument firstc + * is the first character of the input token or document. + * + * Because C does not have internal subroutines, I have simulated them + * using goto's to implement the subroutine linkage. The following macros + * will run code that appears at the end of readtoken1. + */ + +#define CHECKEND() {goto checkend; checkend_return:;} +#define PARSEREDIR() {goto parseredir; parseredir_return:;} +#define PARSESUB() {goto parsesub; parsesub_return:;} +#define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;} +#define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;} +#define PARSEARITH() {goto parsearith; parsearith_return:;} + +STATIC int +readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs) +{ + int c = firstc; + char *out; + int len; + char line[EOFMARKLEN + 1]; + struct nodelist *bqlist; + int quotef; + int dblquote; + int varnest; /* levels of variables expansion */ + int arinest; /* levels of arithmetic expansion */ + int parenlevel; /* levels of parens in arithmetic */ + int dqvarnest; /* levels of variables expansion within double quotes */ + int oldstyle; + char const *prevsyntax; /* syntax before arithmetic */ +#if __GNUC__ + /* Avoid longjmp clobbering */ + (void) &out; + (void) "ef; + (void) &dblquote; + (void) &varnest; + (void) &arinest; + (void) &parenlevel; + (void) &dqvarnest; + (void) &oldstyle; + (void) &prevsyntax; + (void) &syntax; +#endif + + startlinno = plinno; + dblquote = 0; + if (syntax == DQSYNTAX) + dblquote = 1; + quotef = 0; + bqlist = NULL; + varnest = 0; + arinest = 0; + parenlevel = 0; + dqvarnest = 0; + + STARTSTACKSTR(out); + loop: { /* for each line, until end of word */ +#if ATTY + if (c == '\034' && doprompt + && attyset() && ! equal(termval(), "emacs")) { + attyline(); + if (syntax == BASESYNTAX) + return readtoken(); + c = pgetc(); + goto loop; + } +#endif + CHECKEND(); /* set c to PEOF if at end of here document */ + for (;;) { /* until end of line or end of word */ + CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */ + switch(syntax[c]) { + case CNL: /* '\n' */ + if (syntax == BASESYNTAX) + goto endword; /* exit outer loop */ + USTPUTC(c, out); + plinno++; + if (doprompt) + setprompt(2); + c = pgetc(); + goto loop; /* continue outer loop */ + case CWORD: + USTPUTC(c, out); + break; + case CCTL: + if (eofmark == NULL || dblquote) + USTPUTC(CTLESC, out); + USTPUTC(c, out); + break; + case CBACK: /* backslash */ + c = pgetc2(); + if (c == PEOF) { + USTPUTC(CTLESC, out); + USTPUTC('\\', out); + pungetc(); + } else if (c == '\n') { + if (doprompt) + setprompt(2); + } else { + if ( + dblquote && + c != '\\' && c != '`' && + c != '$' && ( + c != '"' || + eofmark != NULL + ) + ) { + USTPUTC(CTLESC, out); + USTPUTC('\\', out); + } + if (SQSYNTAX[c] == CCTL) + USTPUTC(CTLESC, out); + USTPUTC(c, out); + quotef++; + } + break; + case CSQUOTE: + syntax = SQSYNTAX; +quotemark: + if (eofmark == NULL) { + USTPUTC(CTLQUOTEMARK, out); + } + break; + case CDQUOTE: + syntax = DQSYNTAX; + dblquote = 1; + goto quotemark; + case CENDQUOTE: + if (eofmark != NULL && arinest == 0 && + varnest == 0) { + USTPUTC(c, out); + } else { + if (dqvarnest == 0) { + syntax = BASESYNTAX; + dblquote = 0; + } + quotef++; + goto quotemark; + } + break; + case CVAR: /* '$' */ + PARSESUB(); /* parse substitution */ + break; + case CENDVAR: /* '}' */ + if (varnest > 0) { + varnest--; + if (dqvarnest > 0) { + dqvarnest--; + } + USTPUTC(CTLENDVAR, out); + } else { + USTPUTC(c, out); + } + break; + case CLP: /* '(' in arithmetic */ + parenlevel++; + USTPUTC(c, out); + break; + case CRP: /* ')' in arithmetic */ + if (parenlevel > 0) { + USTPUTC(c, out); + --parenlevel; + } else { + if (pgetc() == ')') { + if (--arinest == 0) { + USTPUTC(CTLENDARI, out); + syntax = prevsyntax; + if (syntax == DQSYNTAX) + dblquote = 1; + else + dblquote = 0; + } else + USTPUTC(')', out); + } else { + /* + * unbalanced parens + * (don't 2nd guess - no error) + */ + pungetc(); + USTPUTC(')', out); + } + } + break; + case CBQUOTE: /* '`' */ + PARSEBACKQOLD(); + break; + case CEOF: + goto endword; /* exit outer loop */ + case CIGN: + break; + default: + if (varnest == 0) + goto endword; /* exit outer loop */ + if (c != PEOA) { + USTPUTC(c, out); + } + } + c = pgetc_macro(); + } + } +endword: + if (syntax == ARISYNTAX) + synerror("Missing '))'"); + if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL) + synerror("Unterminated quoted string"); + if (varnest != 0) { + startlinno = plinno; + /* { */ + synerror("Missing '}'"); + } + USTPUTC('\0', out); + len = out - (char *)stackblock(); + out = stackblock(); + if (eofmark == NULL) { + if ((c == '>' || c == '<') + && quotef == 0 + && len <= 2 + && (*out == '\0' || is_digit(*out))) { + PARSEREDIR(); + return lasttoken = TREDIR; + } else { + pungetc(); + } + } + quoteflag = quotef; + backquotelist = bqlist; + grabstackblock(len); + wordtext = out; + return lasttoken = TWORD; +/* end of readtoken routine */ + + + +/* + * Check to see whether we are at the end of the here document. When this + * is called, c is set to the first character of the next input line. If + * we are at the end of the here document, this routine sets the c to PEOF. + */ + +checkend: { + if (eofmark) { + if (c == PEOA) { + c = pgetc2(); + } + if (striptabs) { + while (c == '\t') { + c = pgetc2(); + } + } + if (c == *eofmark) { + if (pfgets(line, sizeof line) != NULL) { + char *p, *q; + + p = line; + for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); + if (*p == '\n' && *q == '\0') { + c = PEOF; + plinno++; + needprompt = doprompt; + } else { + pushstring(line, NULL); + } + } + } + } + goto checkend_return; +} + + +/* + * Parse a redirection operator. The variable "out" points to a string + * specifying the fd to be redirected. The variable "c" contains the + * first character of the redirection operator. + */ + +parseredir: { + char fd = *out; + union node *np; + + np = (union node *)stalloc(sizeof (struct nfile)); + if (c == '>') { + np->nfile.fd = 1; + c = pgetc(); + if (c == '>') + np->type = NAPPEND; + else if (c == '|') + np->type = NCLOBBER; + else if (c == '&') + np->type = NTOFD; + else { + np->type = NTO; + pungetc(); + } + } else { /* c == '<' */ + np->nfile.fd = 0; + switch (c = pgetc()) { + case '<': + if (sizeof (struct nfile) != sizeof (struct nhere)) { + np = (union node *)stalloc(sizeof (struct nhere)); + np->nfile.fd = 0; + } + np->type = NHERE; + heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); + heredoc->here = np; + if ((c = pgetc()) == '-') { + heredoc->striptabs = 1; + } else { + heredoc->striptabs = 0; + pungetc(); + } + break; + + case '&': + np->type = NFROMFD; + break; + + case '>': + np->type = NFROMTO; + break; + + default: + np->type = NFROM; + pungetc(); + break; + } + } + if (fd != '\0') + np->nfile.fd = digit_val(fd); + redirnode = np; + goto parseredir_return; +} + + +/* + * Parse a substitution. At this point, we have read the dollar sign + * and nothing else. + */ + +parsesub: { + int subtype; + int typeloc; + int flags; + char *p; + static const char types[] = "}-+?="; + + c = pgetc(); + if ( + c <= PEOA || + (c != '(' && c != '{' && !is_name(c) && !is_special(c)) + ) { + USTPUTC('$', out); + pungetc(); + } else if (c == '(') { /* $(command) or $((arith)) */ + if (pgetc() == '(') { + PARSEARITH(); + } else { + pungetc(); + PARSEBACKQNEW(); + } + } else { + USTPUTC(CTLVAR, out); + typeloc = out - (char *)stackblock(); + USTPUTC(VSNORMAL, out); + subtype = VSNORMAL; + if (c == '{') { + c = pgetc(); + if (c == '#') { + if ((c = pgetc()) == '}') + c = '#'; + else + subtype = VSLENGTH; + } + else + subtype = 0; + } + if (c > PEOA && is_name(c)) { + do { + STPUTC(c, out); + c = pgetc(); + } while (c > PEOA && is_in_name(c)); + } else if (is_digit(c)) { + do { + STPUTC(c, out); + c = pgetc(); + } while (is_digit(c)); + } + else if (is_special(c)) { + USTPUTC(c, out); + c = pgetc(); + } + else +badsub: synerror("Bad substitution"); + + STPUTC('=', out); + flags = 0; + if (subtype == 0) { + switch (c) { + case ':': + flags = VSNUL; + c = pgetc(); + /*FALLTHROUGH*/ + default: + p = strchr(types, c); + if (p == NULL) + goto badsub; + subtype = p - types + VSNORMAL; + break; + case '%': + case '#': + { + int cc = c; + subtype = c == '#' ? VSTRIMLEFT : + VSTRIMRIGHT; + c = pgetc(); + if (c == cc) + subtype++; + else + pungetc(); + break; + } + } + } else { + pungetc(); + } + if (dblquote || arinest) + flags |= VSQUOTE; + *((char *)stackblock() + typeloc) = subtype | flags; + if (subtype != VSNORMAL) { + varnest++; + if (dblquote || arinest) { + dqvarnest++; + } + } + } + goto parsesub_return; +} + + +/* + * Called to parse command substitutions. Newstyle is set if the command + * is enclosed inside $(...); nlpp is a pointer to the head of the linked + * list of commands (passed by reference), and savelen is the number of + * characters on the top of the stack which must be preserved. + */ + +parsebackq: { + struct nodelist **nlpp; + int savepbq; + union node *n; + char *volatile str; + struct jmploc jmploc; + struct jmploc *volatile savehandler; + size_t savelen; + int saveprompt; +#ifdef __GNUC__ + (void) &saveprompt; +#endif + + savepbq = parsebackquote; + if (setjmp(jmploc.loc)) { + if (str) + ckfree(str); + parsebackquote = 0; + handler = savehandler; + longjmp(handler->loc, 1); + } + INTOFF; + str = NULL; + savelen = out - (char *)stackblock(); + if (savelen > 0) { + str = ckmalloc(savelen); + memcpy(str, stackblock(), savelen); + } + savehandler = handler; + handler = &jmploc; + INTON; + if (oldstyle) { + /* We must read until the closing backquote, giving special + treatment to some slashes, and then push the string and + reread it as input, interpreting it normally. */ + char *pout; + int pc; + size_t psavelen; + char *pstr; + + + STARTSTACKSTR(pout); + for (;;) { + if (needprompt) { + setprompt(2); + } + switch (pc = pgetc()) { + case '`': + goto done; + + case '\\': + if ((pc = pgetc()) == '\n') { + plinno++; + if (doprompt) + setprompt(2); + /* + * If eating a newline, avoid putting + * the newline into the new character + * stream (via the STPUTC after the + * switch). + */ + continue; + } + if (pc != '\\' && pc != '`' && pc != '$' + && (!dblquote || pc != '"')) + STPUTC('\\', pout); + if (pc > PEOA) { + break; + } + /* fall through */ + + case PEOF: + case PEOA: + startlinno = plinno; + synerror("EOF in backquote substitution"); + + case '\n': + plinno++; + needprompt = doprompt; + break; + + default: + break; + } + STPUTC(pc, pout); + } +done: + STPUTC('\0', pout); + psavelen = pout - (char *)stackblock(); + if (psavelen > 0) { + pstr = grabstackstr(pout); + setinputstring(pstr); + } + } + nlpp = &bqlist; + while (*nlpp) + nlpp = &(*nlpp)->next; + *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); + (*nlpp)->next = NULL; + parsebackquote = oldstyle; + + if (oldstyle) { + saveprompt = doprompt; + doprompt = 0; + } + + n = list(2); + + if (oldstyle) + doprompt = saveprompt; + else { + if (readtoken() != TRP) + synexpect(TRP); + } + + (*nlpp)->n = n; + if (oldstyle) { + /* + * Start reading from old file again, ignoring any pushed back + * tokens left from the backquote parsing + */ + popfile(); + tokpushback = 0; + } + while (stackblocksize() <= savelen) + growstackblock(); + STARTSTACKSTR(out); + if (str) { + memcpy(out, str, savelen); + STADJUST(savelen, out); + INTOFF; + ckfree(str); + str = NULL; + INTON; + } + parsebackquote = savepbq; + handler = savehandler; + if (arinest || dblquote) + USTPUTC(CTLBACKQ | CTLQUOTE, out); + else + USTPUTC(CTLBACKQ, out); + if (oldstyle) + goto parsebackq_oldreturn; + else + goto parsebackq_newreturn; +} + +/* + * Parse an arithmetic expansion (indicate start of one and set state) + */ +parsearith: { + + if (++arinest == 1) { + prevsyntax = syntax; + syntax = ARISYNTAX; + USTPUTC(CTLARI, out); + if (dblquote) + USTPUTC('"',out); + else + USTPUTC(' ',out); + } else { + /* + * we collapse embedded arithmetic expansion to + * parenthesis, which should be equivalent + */ + USTPUTC('(', out); + } + goto parsearith_return; +} + +} /* end of readtoken */ + + + +#ifdef mkinit +INCLUDE "parser.h" +RESET { + tokpushback = 0; + checkkwd = 0; +} +#endif + +/* + * Returns true if the text contains nothing to expand (no dollar signs + * or backquotes). + */ + +STATIC int +noexpand(char *text) +{ + char *p; + char c; + + p = text; + while ((c = *p++) != '\0') { + if (c == CTLQUOTEMARK) + continue; + if (c == CTLESC) + p++; + else if (BASESYNTAX[(int)c] == CCTL) + return 0; + } + return 1; +} + + +/* + * Return of a legal variable name (a letter or underscore followed by zero or + * more letters, underscores, and digits). + */ + +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; +} + + +/* + * Called when an unexpected token is read during the parse. The argument + * is the token that is expected, or -1 if more than one type of token can + * occur at this point. + */ + +STATIC void +synexpect(int token) +{ + char msg[64]; + + if (token >= 0) { + fmtstr(msg, 64, "%s unexpected (expecting %s)", + tokname[lasttoken], tokname[token]); + } else { + fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); + } + synerror(msg); + /* NOTREACHED */ +} + + +STATIC void +synerror(const char *msg) +{ + error("Syntax error: %s", msg); + /* NOTREACHED */ +} + +STATIC void +setprompt(int which) +{ + struct stackmark smark; + int show; + + needprompt = 0; + whichprompt = which; + +#ifdef SMALL + show = 1; +#else + show = !el; +#endif + if (show) { + setstackmark(&smark); + stalloc(stackblocksize()); + out2str(getprompt(NULL)); + popstackmark(&smark); + } +} + +const char * +expandstr(const char *ps) +{ + union node n; + + /* XXX Fix (char *) cast. */ + setinputstring((char *)ps); + readtoken1(pgetc(), DQSYNTAX, nullstr, 0); + popfile(); + + n.narg.type = NARG; + n.narg.next = NULL; + n.narg.text = wordtext; + n.narg.backquote = backquotelist; + + expandarg(&n, NULL, 0); + return stackblock(); +} + +/* + * called by editline -- any expansions to the prompt + * should be added here. + */ +const char * +getprompt(void *unused) +{ + const char *prompt; + + switch (whichprompt) { + default: +#ifdef DEBUG + return "<internal prompt error>"; +#endif + case 0: + return nullstr; + case 1: + prompt = ps1val(); + break; + case 2: + prompt = ps2val(); + break; + } + + return expandstr(prompt); +} + +const char *const * +findkwd(const char *s) +{ + return findstring( + s, parsekwd, sizeof(parsekwd) / sizeof(const char *) + ); +} |