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parser.c
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parser.c
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/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
* Copyright (c) 1997-2005
* Herbert Xu <herbert@gondor.apana.org.au>. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kenneth Almquist.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if HAVE_ALLOCA_H
#include <alloca.h>
#endif
#include <stdlib.h>
#include "shell.h"
#include "parser.h"
#include "nodes.h"
#include "expand.h" /* defines rmescapes() */
#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"
#include "system.h"
#ifndef SMALL
#include "myhistedit.h"
#endif
/*
* Shell command parser.
*/
/* values returned by readtoken */
#include "token_vars.h"
/* Used by expandstr to get here-doc like behaviour. */
#define FAKEEOFMARK (char *)1
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 synstack {
const char *syntax;
struct synstack *prev;
struct synstack *next;
int innerdq;
int varpushed;
int dblquote;
int varnest; /* levels of variables expansion */
int parenlevel; /* levels of parens in arithmetic */
int dqvarnest; /* levels of variables expansion within double quotes */
};
struct heredoc *heredoclist; /* list of here documents to read */
int doprompt; /* if set, prompt the user */
int needprompt; /* true if interactive and at start of line */
int lasttoken; /* last token read */
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 */
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 readtoken(void);
STATIC int xxreadtoken(void);
STATIC int pgetc_eatbnl();
STATIC int readtoken1(int, char const *, char *, int);
STATIC void synexpect(int) __attribute__((__noreturn__));
STATIC void synerror(const char *) __attribute__((__noreturn__));
STATIC void setprompt(int);
int isassignment(const char *p)
{
const char *q = endofname(p);
if (p == q)
return 0;
return *q == '=';
}
static inline int realeofmark(const char *eofmark)
{
return eofmark && eofmark != FAKEEOFMARK;
}
/*
* 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)
{
tokpushback = 0;
checkkwd = 0;
heredoclist = 0;
doprompt = interact;
if (doprompt)
setprompt(doprompt);
needprompt = 0;
return list(1);
}
STATIC union node *
list(int nlflag)
{
int chknl = nlflag & 1 ? 0 : CHKNL;
union node *n1, *n2, *n3;
int tok;
n1 = NULL;
for (;;) {
checkkwd = chknl | CHKKWD | CHKALIAS;
tok = readtoken();
switch (tok) {
case TNL:
parseheredoc();
return n1;
case TEOF:
if (!n1 && !chknl)
n1 = NEOF;
out_eof:
parseheredoc();
tokpushback++;
lasttoken = TEOF;
return n1;
}
tokpushback++;
if (nlflag == 2 && tokendlist[tok])
return n1;
nlflag |= 2;
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 TEOF:
goto out_eof;
case TNL:
tokpushback++;
/* fall through */
case TBACKGND:
case TSEMI:
break;
default:
if (!chknl)
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;
int savelinno;
redir = NULL;
rpp2 = &redir;
savelinno = plinno;
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.linno = savelinno;
n1->nfor.var = wordtext;
checkkwd = CHKNL | 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 != 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;
n1->ncase.linno = savelinno;
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;
checkkwd = CHKNL | CHKKWD | CHKALIAS;
if (readtoken() != 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.linno = savelinno;
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.linno = savelinno;
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;
int savelinno;
args = NULL;
app = &args;
vars = NULL;
vpp = &vars;
redir = NULL;
rpp = &redir;
savecheckkwd = CHKALIAS;
savelinno = plinno;
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->ndefun.text = n->narg.text;
n->ndefun.linno = plinno;
n->ndefun.body = 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.linno = savelinno;
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 (n->type == NHERE)
checkkwd = CHKEOFMARK;
if (readtoken() != TWORD)
synexpect(-1);
if (n->type == NHERE) {
struct heredoc *here = heredoc;
struct heredoc *p;
if (quoteflag == 0)
n->type = NXHERE;
TRACE(("Here document %d\n", n->type));
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);
}
if (here->here->type == NHERE)
readtoken1(pgetc(), SQSYNTAX, here->eofmark, here->striptabs);
else
readtoken1(pgetc_eatbnl(), 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
readtoken(void)
{
int t;
int kwd = checkkwd;
#ifdef DEBUG
int alreadyseen = tokpushback;
#endif
top:
t = xxreadtoken();
/*
* eat newlines
*/
if (kwd & CHKNL) {
while (t == TNL) {
parseheredoc();
checkkwd = 0;
t = xxreadtoken();
}
}
kwd |= checkkwd;
checkkwd = 0;
if (t != TWORD || quoteflag) {
goto out;
}
/*
* check for keywords
*/
if (kwd & CHKKWD) {
const char *const *pp;
if ((pp = findkwd(wordtext))) {
lasttoken = t = pp - parsekwd + KWDOFFSET;
TRACE(("keyword %s recognized\n", tokname[t]));
goto out;
}
}
if (kwd & CHKALIAS) {
struct alias *ap;
if ((ap = lookupalias(wordtext, 1)) != NULL) {
if (*ap->val) {
pushstring(ap->val, ap);
}
goto top;
}
}
out:
#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);
}
static void nlprompt(void)
{
plinno++;
if (doprompt)
setprompt(2);
}
static void nlnoprompt(void)
{
plinno++;
needprompt = doprompt;
}
/*
* 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.
*
* [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);
}
for (;;) { /* until token or start of word found */
c = pgetc_eatbnl();
switch (c) {
case ' ': case '\t':
continue;
case '#':
while ((c = pgetc()) != '\n' && c != PEOF);
pungetc();
continue;
case '\n':
nlnoprompt();
RETURN(TNL);
case PEOF:
RETURN(TEOF);
case '&':
if (pgetc_eatbnl() == '&')
RETURN(TAND);
pungetc();
RETURN(TBACKGND);
case '|':
if (pgetc_eatbnl() == '|')
RETURN(TOR);
pungetc();
RETURN(TPIPE);
case ';':
if (pgetc_eatbnl() == ';')
RETURN(TENDCASE);
pungetc();
RETURN(TSEMI);
case '(':
RETURN(TLP);
case ')':
RETURN(TRP);
}
break;
}
return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
#undef RETURN
}
static int pgetc_eatbnl(void)
{
int c;
while ((c = pgetc()) == '\\') {
if (pgetc() != '\n') {
pungetc();
break;
}
nlprompt();
}
return c;
}
static int pgetc_top(struct synstack *stack)
{
return stack->syntax == SQSYNTAX ? pgetc() : pgetc_eatbnl();
}
static void synstack_push(struct synstack **stack, struct synstack *next,
const char *syntax)
{
memset(next, 0, sizeof(*next));
next->syntax = syntax;
next->next = *stack;
(*stack)->prev = next;
*stack = next;
}
static void synstack_pop(struct synstack **stack)
{
*stack = (*stack)->next;
}
/*
* 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;
size_t len;
struct nodelist *bqlist;
int quotef;
int oldstyle;
/* syntax stack */
struct synstack synbase = { .syntax = syntax };
struct synstack *synstack = &synbase;
if (syntax == DQSYNTAX)
synstack->dblquote = 1;
quotef = 0;
bqlist = NULL;
STARTSTACKSTR(out);
loop: { /* for each line, until end of word */
#if ATTY
if (c == '\034' && doprompt
&& attyset() && ! equal(termval(), "emacs")) {
attyline();
if (synstack->syntax == BASESYNTAX)
return readtoken();
c = pgetc_top(synstack);
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(synstack->syntax[c]) {
case CNL: /* '\n' */
if (synstack->syntax == BASESYNTAX &&
!synstack->varnest)
goto endword; /* exit outer loop */
USTPUTC(c, out);
nlprompt();
c = pgetc_top(synstack);
goto loop; /* continue outer loop */
case CWORD:
USTPUTC(c, out);
break;
case CCTL:
if ((!eofmark) | synstack->dblquote |
synstack->varnest)
USTPUTC(CTLESC, out);
USTPUTC(c, out);
break;
/* backslash */
case CBACK:
c = pgetc();
if (c == PEOF) {
USTPUTC(CTLESC, out);
USTPUTC('\\', out);
pungetc();
} else {
if (
synstack->dblquote &&
c != '\\' && c != '`' &&
c != '$' && (
c != '"' ||
(eofmark != NULL &&
!synstack->varnest)
) && (
c != '}' ||
!synstack->varnest
)
) {
USTPUTC(CTLESC, out);
USTPUTC('\\', out);
}
USTPUTC(CTLESC, out);
USTPUTC(c, out);
quotef++;
}
break;
case CSQUOTE:
synstack->syntax = SQSYNTAX;
quotemark:
if (eofmark == NULL) {
USTPUTC(CTLQUOTEMARK, out);
}
break;
case CDQUOTE:
synstack->syntax = DQSYNTAX;
synstack->dblquote = 1;
toggledq:
if (synstack->varnest)
synstack->innerdq ^= 1;
goto quotemark;
case CENDQUOTE:
if (eofmark && !synstack->varnest) {
USTPUTC(c, out);
break;
}
if (synstack->dqvarnest == 0) {
synstack->syntax = BASESYNTAX;
synstack->dblquote = 0;
}
quotef++;
if (c == '"')
goto toggledq;