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-rw-r--r--usr/dash/parser.c1568
1 files changed, 1568 insertions, 0 deletions
diff --git a/usr/dash/parser.c b/usr/dash/parser.c
new file mode 100644
index 0000000..6e076a5
--- /dev/null
+++ b/usr/dash/parser.c
@@ -0,0 +1,1568 @@
+/*-
+ * 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.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 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 */
+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 */
+
+
+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 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 == '=';
+}
+
+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)
+{
+ 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;
+ 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 = &ap;
+ 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);
+ }
+ 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;
+ int kwd = checkkwd;
+#ifdef DEBUG
+ int alreadyseen = tokpushback;
+#endif
+
+top:
+ t = xxreadtoken();
+
+ /*
+ * eat newlines
+ */
+ if (kwd & CHKNL) {
+ while (t == TNL) {
+ parseheredoc();
+ t = xxreadtoken();
+ }
+ }
+
+ 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 (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.
+ *
+ * [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_macro();
+ switch (c) {
+ case ' ': case '\t':
+ case PEOA:
+ continue;
+ case '#':
+ while ((c = pgetc()) != '\n' && c != PEOF);
+ pungetc();
+ continue;
+ case '\\':
+ if (pgetc() == '\n') {
+ 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;
+ size_t len;
+ 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;
+ /* syntax before arithmetic */
+ char const *uninitialized_var(prevsyntax);
+
+ 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;
+ /* backslash */
+ case CBACK:
+ c = pgetc2();
+ if (c == PEOF) {
+ USTPUTC(CTLESC, out);
+ USTPUTC('\\', out);
+ pungetc();
+ } else if (c == '\n') {
+ plinno++;
+ if (doprompt)
+ setprompt(2);
+ } else {
+ if (
+ dblquote &&
+ c != '\\' && c != '`' &&
+ c != '$' && (
+ c != '"' ||
+ eofmark != NULL
+ )
+ ) {
+ USTPUTC('\\', out);
+ }
+ USTPUTC(CTLESC, out);
+ USTPUTC(c, out);
+ quotef++;
+ }
+ break;
+ case CSQUOTE:
+ syntax = SQSYNTAX;
+quotemark:
+ if (eofmark == NULL) {
+ USTPUTC(CTLQUOTEMARK, out);
+ }
+ break;
+ case CDQUOTE:
+ syntax = DQSYNTAX;
+ dblquote = 1;
+ goto quotemark;
+ case CENDQUOTE:
+ if (eofmark && !varnest)
+ USTPUTC(c, out);
+ else {
+ if (dqvarnest == 0) {
+ syntax = BASESYNTAX;
+ dblquote = 0;
+ }
+ quotef++;
+ goto quotemark;
+ }
+ break;
+ case CVAR: /* '$' */
+ 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() == ')') {
+ USTPUTC(CTLENDARI, out);
+ if (!--arinest)
+ syntax = prevsyntax;
+ } 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 && eofmark == NULL)
+ synerror("Unterminated quoted string");
+ if (varnest != 0) {
+ /* { */
+ 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 (realeofmark(eofmark)) {
+ int markloc;
+ char *p;
+
+ if (c == PEOA) {
+ c = pgetc2();
+ }
+ if (striptabs) {
+ while (c == '\t') {
+ c = pgetc2();
+ }
+ }
+
+ markloc = out - (char *)stackblock();
+ for (p = eofmark; STPUTC(c, out), *p; p++) {
+ if (c != *p)
+ goto more_heredoc;
+
+ c = pgetc2();
+ }
+
+ if (c == '\n' || c == PEOF) {
+ c = PEOF;
+ plinno++;
+ needprompt = doprompt;
+ } else {
+ int len;
+
+more_heredoc:
+ p = (char *)stackblock() + markloc + 1;
+ len = out - p;
+
+ if (len) {
+ len -= c < 0;
+ c = p[-1];
+
+ if (len) {
+ char *str;
+
+ str = alloca(len + 1);
+ *(char *)mempcpy(str, p, len) = 0;
+
+ pushstring(str, NULL);
+ }
+ }
+ }
+
+ STADJUST((char *)stackblock() + markloc - out, out);
+ }
+ 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;
+ char *p;
+ static const char types[] = "}-+?=";
+
+ c = pgetc();
+ if (
+ (checkkwd & CHKEOFMARK) ||
+ 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();
+ STADJUST(1, out);
+ subtype = VSNORMAL;
+ if (likely(c == '{')) {
+ c = pgetc();
+ subtype = 0;
+ }
+varname:
+ if (is_name(c)) {
+ do {
+ STPUTC(c, out);
+ c = pgetc();
+ } while (is_in_name(c));
+ } else if (is_digit(c)) {
+ do {
+ STPUTC(c, out);
+ c = pgetc();
+ } while (is_digit(c));
+ }
+ else if (is_special(c)) {
+ int cc = c;
+
+ c = pgetc();
+
+ if (!subtype && cc == '#') {
+ subtype = VSLENGTH;
+
+ if (c == '_' || isalnum(c))
+ goto varname;
+
+ cc = c;
+ c = pgetc();
+ if (cc == '}' || c != '}') {
+ pungetc();
+ subtype = 0;
+ c = cc;
+ cc = '#';
+ }
+ }
+
+ USTPUTC(cc, out);
+ }
+ else
+ goto badsub;
+
+ if (subtype == 0) {
+ switch (c) {
+ case ':':
+ subtype = VSNUL;
+ c = pgetc();
+ /*FALLTHROUGH*/
+ default:
+ p = strchr(types, c);
+ if (p == NULL)
+ break;
+ subtype |= p - types + VSNORMAL;
+ break;
+ case '%':
+ case '#':
+ {
+ int cc = c;
+ subtype = c == '#' ? VSTRIMLEFT :
+ VSTRIMRIGHT;
+ c = pgetc();
+ if (c == cc)
+ subtype++;
+ else
+ pungetc();
+ break;
+ }
+ }
+ } else {
+badsub:
+ pungetc();
+ }
+ *((char *)stackblock() + typeloc) = subtype;
+ if (subtype != VSNORMAL) {
+ varnest++;
+ if (dblquote)
+ dqvarnest++;
+ }
+ STPUTC('=', out);
+ }
+ goto parsesub_return;
+}
+
+
+/*
+ * Called to parse command substitutions. Newstyle is set if the command
+ * is enclosed inside $(...); nlpp is a pointer to the head of the linked
+ * list of commands (passed by reference), and savelen is the number of
+ * characters on the top of the stack which must be preserved.
+ */
+
+parsebackq: {
+ struct nodelist **nlpp;
+ union node *n;
+ char *str;
+ size_t savelen;
+ int uninitialized_var(saveprompt);
+
+ str = NULL;
+ savelen = out - (char *)stackblock();
+ if (savelen > 0) {
+ str = alloca(savelen);
+ memcpy(str, stackblock(), savelen);
+ }
+ if (oldstyle) {
+ /* We must read until the closing backquote, giving special
+ treatment to some slashes, and then push the string and
+ reread it as input, interpreting it normally. */
+ char *pout;
+ int pc;
+ size_t psavelen;
+ char *pstr;
+
+
+ STARTSTACKSTR(pout);
+ for (;;) {
+ if (needprompt) {
+ setprompt(2);
+ }
+ switch (pc = pgetc()) {
+ case '`':
+ goto done;
+
+ case '\\':
+ if ((pc = pgetc()) == '\n') {
+ plinno++;
+ if (doprompt)
+ setprompt(2);
+ /*
+ * If eating a newline, avoid putting
+ * the newline into the new character
+ * stream (via the STPUTC after the
+ * switch).
+ */
+ continue;
+ }
+ if (pc != '\\' && pc != '`' && pc != '$'
+ && (!dblquote || pc != '"'))
+ STPUTC('\\', pout);
+ if (pc > PEOA) {
+ break;
+ }
+ /* fall through */
+
+ case PEOF:
+ case PEOA:
+ 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;
+
+ 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);
+ }
+ 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);
+ goto parsearith_return;
+}
+
+} /* end of readtoken */
+
+
+
+#ifdef mkinit
+INCLUDE "parser.h"
+RESET {
+ tokpushback = 0;
+ checkkwd = 0;
+}
+#endif
+
+
+/*
+ * 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)
+{
+ errlinno = plinno;
+ sh_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) {
+ pushstackmark(&smark, stackblocksize());
+ out2str(getprompt(NULL));
+ popstackmark(&smark);
+ }
+}
+
+const char *
+expandstr(const char *ps)
+{
+ union node n;
+ int saveprompt;
+
+ /* XXX Fix (char *) cast. */
+ setinputstring((char *)ps);
+
+ saveprompt = doprompt;
+ doprompt = 0;
+
+ readtoken1(pgetc(), DQSYNTAX, FAKEEOFMARK, 0);
+
+ doprompt = saveprompt;
+
+ popfile();
+
+ n.narg.type = NARG;
+ n.narg.next = NULL;
+ n.narg.text = wordtext;
+ n.narg.backquote = backquotelist;
+
+ expandarg(&n, NULL, EXP_QUOTED);
+ 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 *)
+ );
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-22 01:15:35 +0000