/*
 * awk1 -- Expression tree constructors and main program for gawk. 
 *
 * Copyright (C) 1986 Free Software Foundation Written by Paul Rubin, August
 * 1986 
 *
 * $Log:	awk1.c,v $
 * Revision 1.30  88/12/15  12:56:18  david
 * changes from Jay to compile under gcc and fixing a bug in treatment of
 * input files
 * 
 * Revision 1.29  88/12/08  15:57:41  david
 * *** empty log message ***
 * 
 * Revision 1.28  88/12/07  20:00:15  david
 * changes for incorporating source filename into error messages
 * 
 * Revision 1.27  88/12/01  15:05:26  david
 * changes to allow source line number printing in error messages
 * 
 * Revision 1.26  88/11/28  20:12:30  david
 * unbuffer stdout if compiled with DEBUG
 * 
 * Revision 1.25  88/11/23  21:39:57  david
 * Arnold: set strict if invoked as "awk"
 * 
 * Revision 1.24  88/11/22  13:47:40  david
 * Arnold: changes for case-insensitive matching
 * 
 * Revision 1.23  88/11/15  10:18:57  david
 * Arnold: cleanup; allow multiple -f options; if invoked as awk disable
 * -v option for compatability
 * 
 * Revision 1.22  88/11/14  21:54:27  david
 * Arnold: cleanup
 * 
 * Revision 1.21  88/11/03  15:22:22  david
 * revised flags
 * 
 * Revision 1.20  88/11/01  11:47:24  david
 * mostly cleanup and code movement
 * 
 * Revision 1.19  88/10/19  21:56:00  david
 * replace malloc with emalloc
 * 
 * Revision 1.18  88/10/17  20:57:19  david
 * Arnold: purge FAST
 * 
 * Revision 1.17  88/10/14  22:11:24  david
 * pathc from Hack to get gcc to work
 * 
 * Revision 1.16  88/10/13  21:55:08  david
 * purge FAST; clean up error messages
 * 
 * Revision 1.15  88/10/06  21:55:20  david
 * be more careful about I/O errors on exit
 * Arnold's fixes for command line processing
 * 
 * Revision 1.14  88/10/06  15:52:24  david
 * changes from Arnold: use getopt; ifdef -v option; change semantics of = args.
 * 
 * Revision 1.13  88/09/26  10:16:35  david
 * cleanup from Arnold
 * 
 * Revision 1.12  88/09/19  20:38:29  david
 * added -v option
 * set FILENAME to "-" if stdin
 * 
 * Revision 1.11  88/08/09  14:49:23  david
 * reorganized handling of command-line arguments and files
 * 
 * Revision 1.10  88/06/13  18:08:25  david
 * delete \a and -R options
 * separate exit value from flag indicating that exit has been called
 * [from Arnold]
 * 
 * Revision 1.9  88/06/05  22:19:41  david
 * func_level goes away; param_counter is used to count order of local vars.
 * 
 * Revision 1.8  88/05/31  09:21:56  david
 * Arnold's portability changes (vprintf)
 * fixed handling of function parameter use inside function
 * 
 * Revision 1.7  88/05/30  09:51:17  david
 * exit after yyparse() if any errors were encountered
 * mk_re_parse() parses C escapes in regexps.
 * do panic() properly with varargs
 * clean up and simplify pop_var()
 * 
 * Revision 1.6  88/05/26  22:46:19  david
 * minor changes: break out separate case for making regular expressions
 *   from parser vs. from strings
 * 
 * Revision 1.5  88/05/13  22:02:31  david
 * moved BEGIN and END block merging into parse-phase (sorry Arnold)
 * if there is only a BEGIN block and nothing else, don't read any files
 * cleaned up func_install a bit
 * 
 * Revision 1.4  88/05/04  12:18:28  david
 * make_for_loop() now returns a NODE *
 * pop_var() now returns the value of the node being popped, to be used
 * in func_call() if the variable is an array (call by reference)
 * 
 * Revision 1.3  88/04/15  13:12:19  david
 * small fix to arg reading code
 * 
 * Revision 1.2  88/04/14  14:40:25  david
 * Arnold's changes to read program from a file
 * 
 * Revision 1.1  88/04/08  15:14:52  david
 * Initial revision
 *  Revision 1.6  88/04/08  14:48:30  david changes from
 * Arnold Robbins 
 *
 * Revision 1.5  88/03/28  14:13:33  david *** empty log message *** 
 *
 * Revision 1.4  88/03/23  22:17:33  david mostly delinting -- a couple of bug
 * fixes 
 *
 * Revision 1.3  88/03/18  21:00:09  david Baseline -- hoefully all the
 * functionality of the new awk added. Just debugging and tuning to do. 
 *
 * Revision 1.2  87/11/19  14:40:17  david added support for user-defined
 * functions 
 *
 * Revision 1.1  87/10/27  15:23:26  david Initial revision 
 *
 */

/*
 * GAWK is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY.  No author or distributor accepts responsibility to anyone for
 * the consequences of using it or for whether it serves any particular
 * purpose or works at all, unless he says so in writing. Refer to the GAWK
 * General Public License for full details. 
 *
 * Everyone is granted permission to copy, modify and redistribute GAWK, but
 * only under the conditions described in the GAWK General Public License.  A
 * copy of this license is supposed to have been given to you along with GAWK
 * so you can know your rights and responsibilities.  It should be in a file
 * named COPYING.  Among other things, the copyright notice and this notice
 * must be preserved on all copies. 
 *
 * In other words, go ahead and share GAWK, but don't try to stop anyone else
 * from sharing it farther.  Help stamp out software hoarding! 
 */

#include "awk.h"

/*
 * The parse tree and field nodes are stored here.  Parse_end is a dummy item
 * used to free up unneeded fields without freeing the program being run 
 */
int errcount = 0;	/* error counter, used by yyerror() */
int param_counter;

/* The global null string */
NODE *Nnull_string;

/* The special variable that contains the name of the current input file */
extern NODE *FILENAME_node;
extern NODE *ARGC_node;
extern NODE *ARGV_node;

/* The name the program was invoked under, for error messages */
char *myname;

/* A block of AWK code to be run before running the program */
NODE *begin_block = 0;

/* A block of AWK code to be run after the last input file */
NODE *end_block = 0;

FILE *input_file;		/* Where to read from */

int exiting = 0;		/* Was an "exit" statement executed? */
int exit_val = 0;		/* optional exit value */

#ifdef DEBUG
/* non-zero means in debugging is enabled.  Probably not very useful */
int debugging = 0;

#endif

int tempsource = 0;		/* source is in a temp file */
char **sourcefile = NULL;	/* source file name(s) */
int numfiles = -1;		/* how many source files */

int ignorecase = 0;		/* global flag for ignoring case */

int strict = 0;			/* turn off gnu extensions */

main(argc, argv)
int argc;
char **argv;
{
#ifdef DEBUG
	/* Print out the parse tree.   For debugging */
	register int dotree = 0;
	extern int yydebug;

#endif
	extern char *lexptr;
	extern char *lexptr_begin;
	extern char *version_string;
	extern FILE *nextfile();
	FILE *fp, *fopen();
	static char template[] = "/tmp/gawk.XXXXX";
 	char *mktemp ();
	int c;
	extern int opterr, optind, getopt();
	extern char *optarg;
	char *cp, *rindex();
	/*
	 * for strict to work, legal options must be first
	 */
#define EXTENSIONS	4	/* where to clear */
#ifdef DEBUG
	char *awk_opts = "F:f:ivdD";
#else
	char *awk_opts = "F:f:iv";
#endif

#ifdef DEBUG
	/*malloc_debug(2);*/
#endif
	myname = argv[0];
	if (argc < 2)
		usage();

	/* Tell the regex routines how they should work. . . */
	(void) re_set_syntax(RE_SYNTAX_AWK);

	/* initialize the null string */
	Nnull_string = make_string("", 0);
	Nnull_string->numbr = 0.0;
	Nnull_string->type = Node_val;
	Nnull_string->flags = (PERM|STR|NUM);

	/* Set up the special variables */

	/*
	 * Note that this must be done BEFORE arg parsing else -F
	 * breaks horribly 
	 */
	init_vars();

	/* worst case */
	emalloc(sourcefile, char **, argc * sizeof(char *), "main");


#ifdef STRICT	/* strict Unix awk compatibility */
	strict = 1;
#else
	/* if invoked as 'awk', also behave strictly */
	if ((cp = rindex(myname, '/')) != NULL)
		cp++;
	else
		cp = myname;
	if (strcmp (cp, "awk") == 0)
		strict = 1;
#endif

	if (strict)
		awk_opts[EXTENSIONS] = '\0';

	while ((c = getopt (argc, argv, awk_opts)) != EOF) {
		switch (c) {
#ifdef DEBUG
		case 'd':
			debugging++;
			dotree++;
			break;

		case 'D':
			debugging++;
			yydebug = 2;
			break;
#endif

		case 'F':
			set_fs(optarg);
			break;

		case 'f':
			/*
			 * a la MKS awk, allow multiple -f options.
			 * this makes function libraries real easy.
			 * most of the magic is in the scanner.
			 */
			sourcefile[++numfiles] = optarg;
			break;

		case 'i':
			ignorecase = 1;
			break;

		case 'v':
			fprintf(stderr, "%s", version_string);
			break;

		case '?':
		default:
			/* getopt will print a message for us */
			/* S5R4 awk ignores bad options and keeps going */
			break;
		}
	}
#ifdef DEBUG
	setbuf(stdout, (char *) NULL);	/* make debugging easier */
#endif
	/* No -f option, use next arg */
	/* write to temp file and save sourcefile name */
	if (numfiles == -1) {
		int i;

		if (optind > argc - 1)	/* no args left */
			usage();
		numfiles++;
		sourcefile[0] = mktemp (template);
		i = strlen (argv[optind]);
		if ((fp = fopen (sourcefile[0], "w")) == NULL)
			fatal("could not save source prog in temp file (%s)",
			sys_errlist[errno]);
		if (fwrite (argv[optind], 1, i, fp) == 0)
			fatal(
			"could not write source program to temp file (%s)",
			sys_errlist[errno]);
		if (argv[optind][i-1] != '\n')
			putc ('\n', fp);
		(void) fclose (fp);
		tempsource++;
		optind++;
	}
	init_args(optind, argc, myname, argv);

	/* Read in the program */
	lexptr_begin = lexptr;
	if (yyparse() || errcount)
		exit(1);

#ifdef DEBUG
	if (dotree)
		print_parse_tree(expression_value);
#endif
	/* Set up the field variables */
	init_fields();

	if (begin_block)
		(void) interpret(begin_block);
	if (!exiting && (expression_value || end_block)) {
		if(input_file)
			do_file(input_file);
		while ((fp = nextfile()) != NULL) {
			do_file(fp);
			if (exiting)
				break;
		}
	}
	if (end_block)
		(void) interpret(end_block);
	if (flush_io() != 0 && exit_val == 0)
		exit_val = 1;
	if (close_io() != 0 && exit_val == 0)
		exit_val = 1;
	exit(exit_val);
}

do_file(fp)
FILE *fp;
{
	input_file = fp;
	/* This is where it spends all its time.  The infamous MAIN LOOP */
	if (inrec() == 0) {
		while (interpret(expression_value) && inrec() == 0)
			;
	}
	if (fp != stdin)
		(void) fclose(fp);
}

usage()
{
#ifdef STRICT
	char *opt1 = "[ -Ffs ] -f progfile [ -- ]";
	char *opt2 = "[ -Ffs ] [ -- ] 'program'";
#else
	char *opt1 = "[ -v ] [ -Ffs ] -f progfile [ -- ]";
	char *opt2 = "[ -v ] [ -Ffs ] [ -- ] 'program'";
#endif

	fprintf(stderr, "usage: %s %s file ...\n       %s %s file ...\n",
		myname, opt1, myname, opt2);
	exit(11);
}

NODE *
node_common(op)
NODETYPE op;
{
	register NODE *r;
	extern int lineno;
	extern int numfiles;
	extern int tempsource;
	extern char **sourcefile;
	extern int curinfile;

	emalloc(r, NODE *, sizeof(NODE), "node_common");
	r->type = op;
	r->source_line = lineno;
	if (numfiles > 1 && !tempsource)
		r->source_file = sourcefile[curinfile];
	else
		r->source_file = NULL;
	return r;
}

/*
 * This allocates a node with defined lnode and rnode. 
 * This should only be used by yyparse+co while reading in the program 
 */
NODE *
node(left, op, right)
NODE *left, *right;
NODETYPE op;
{
	register NODE *r;

	r = node_common(op);
	r->lnode = left;
	r->rnode = right;
	return r;
}

/*
 * This allocates a node with defined subnode and proc
 * Otherwise like node()
 */
NODE *
snode(subn, op, procp)
NODETYPE op;
NODE *(*procp) ();
NODE *subn;
{
	register NODE *r;

	r = node_common(op);
	r->subnode = subn;
	r->proc = procp;
	return r;
}

/*
 * This allocates a Node_line_range node with defined condpair and
 * zeroes the trigger word to avoid the temptation of assuming that calling
 * 'node( foo, Node_line_range, 0)' will properly initialize 'triggered'. 
 */
/* Otherwise like node() */
NODE *
mkrangenode(cpair)
NODE *cpair;
{
	register NODE *r;

	emalloc(r, NODE *, sizeof(NODE), "mkrangenode");
	r->type = Node_line_range;
	r->condpair = cpair;
	r->triggered = 0;
	return r;
}

struct re_pattern_buffer *
mk_re_parse(s)
char *s;
{
	register char *src, *dest;
	int c;

	for (dest = src = s; *src != '\0'; src++) {
		if (*src == '\\') {
			c = *++src;
			switch (c) {
			case 'b':
				*dest++ = '\b';
				break;
			case 'f':
				*dest++ = '\f';
				break;
			case 'n':
				*dest++ = '\n';
				break;
			case 'r':
				*dest++ = '\r';
				break;
			case 't':
				*dest++ = '\t';
				break;
			case 'v':
				*dest++ = '\v';
				break;
			case '0':
			case '1':
			case '2':
			case '3':
			case '4':
			case '5':
			case '6':
			case '7':
				{
				register int i = c - '0';
				register int count = 0;
	
				while (++count < 3) {
					if ((c = *++src) >= '0' && c <= '7') {
						i *= 8;
						i += c - '0';
					} else
						break;
				}
				*dest++ = i;
				}
				break;
			default:
				*dest++ = '\\';
				*dest++ = c;
				break;
			}
		} else if (*src == '/')
			break;
		else
			*dest++ = *src;
	}
	return make_regexp(tmp_string(s, dest-s));
}

/* Generate compiled regular expressions */
struct re_pattern_buffer *
make_regexp(s)
NODE *s;
{
	struct re_pattern_buffer *rp;
	char *err;

	emalloc(rp, struct re_pattern_buffer *, sizeof(*rp), "make_regexp");
	bzero((char *) rp, sizeof(*rp));
	emalloc(rp->buffer, char *, 8, "make_regexp");
	rp->allocated = 8;
	emalloc(rp->fastmap, char *, 256, "make_regexp");

	if ((err = re_compile_pattern(s->stptr, s->stlen, rp)) != NULL)
		fatal("%s: /%s/", err, s->stptr);
	free_temp(s);
	return rp;
}

/* Build a for loop */
NODE *
make_for_loop(init, cond, incr)
NODE *init, *cond, *incr;
{
	register FOR_LOOP_HEADER *r;
	NODE *n;

	emalloc(r, FOR_LOOP_HEADER *, sizeof(FOR_LOOP_HEADER), "make_for_loop");
	emalloc(n, NODE *, sizeof(NODE), "make_for_loop");
	r->init = init;
	r->cond = cond;
	r->incr = incr;
	n->type = Node_illegal;
	n->sub.nodep.r.hd = r;
	return n;
}

/* Name points to a variable name.  Make sure its in the symbol table */
NODE *
variable(name)
char *name;
{
	register NODE *r;
	NODE *lookup(), *install(), *make_name();

	if ((r = lookup(variables, name)) == NULL)
		r = install(variables, name,
			node(Nnull_string, Node_var, (NODE *) NULL));
	return r;
}

/* Create a special variable */
NODE *
spc_var(name, value)
char *name;
NODE *value;
{
	register NODE *r;
	NODE *lookup(), *install();

	if ((r = lookup(variables, name)) == NULL)
		r = install(variables, name, node(value, Node_var, (NODE *) NULL));
	return r;
}



/*
 * Install a name in the hash table specified, even if it is already there.
 * Name stops with first non alphanumeric. Caller must check against
 * redefinition if that is desired. 
 */
NODE *
install(table, name, value)
HASHNODE **table;
char *name;
NODE *value;
{
	register HASHNODE *hp;
	register int i, len, bucket;
	register char *p;

	len = 0;
	p = name;
	while (is_identchar(*p))
		p++;
	len = p - name;

	i = sizeof(HASHNODE) + len + 1;
	emalloc(hp, HASHNODE *, i, "install");
	bucket = hashf(name, len, HASHSIZE);
	hp->next = table[bucket];
	table[bucket] = hp;
	hp->length = len;
	hp->value = value;
	hp->name = ((char *) hp) + sizeof(HASHNODE);
	hp->length = len;
	bcopy(name, hp->name, len);
	hp->name[len] = '\0';
	hp->value->varname = hp->name;
	return hp->value;
}

/*
 * find the most recent hash node for name name (ending with first
 * non-identifier char) installed by install 
 */
NODE *
lookup(table, name)
HASHNODE **table;
char *name;
{
	register char *bp;
	register HASHNODE *bucket;
	register int len;

	for (bp = name; is_identchar(*bp); bp++)
		;
	len = bp - name;
	bucket = table[hashf(name, len, HASHSIZE)];
	while (bucket) {
		if (bucket->length == len && strncmp(bucket->name, name, len) == 0)
			return bucket->value;
		bucket = bucket->next;
	}
	return NULL;
}

#define HASHSTEP(old, c) ((old << 1) + c)
#define MAKE_POS(v) (v & ~0x80000000)	/* make number positive */

/*
 * return hash function on name.
 */
int
hashf(name, len, hashsize)
register char *name;
register int len;
int hashsize;
{
	register int r = 0;

	while (len--)
		r = HASHSTEP(r, *name++);

	r = MAKE_POS(r) % hashsize;
	return r;
}

/*
 * Add new to the rightmost branch of LIST.  This uses n^2 time, but doesn't
 * get used enough to make optimizing worth it. . . 
 */
/* You don't believe me?  Profile it yourself! */

NODE *
append_right(list, new)
NODE *list, *new;
{
	register NODE *oldlist;

	oldlist = list;
	while (list->rnode != NULL)
		list = list->rnode;
	list->rnode = new;
	return oldlist;
}

/*
 * check if name is already installed;  if so, it had better have Null value,
 * in which case def is added as the value. Otherwise, install name with def
 * as value. 
 */
func_install(params, def)
NODE *params;
NODE *def;
{
	NODE *r;
	NODE *lookup();

	pop_params(params);
	r = lookup(variables, params->param);
	if (r != NULL) {
		fatal("function name `%s' previously defined", params->param);
	} else
		(void) install(variables, params->param,
			node(params, Node_func, def));
}

NODE *
pop_var(name)
char *name;
{
	register char *bp;
	register HASHNODE *bucket, **save;
	register int len;

	for (bp = name; is_identchar(*bp); bp++)
		;
	len = bp - name;
	save = &(variables[hashf(name, len, HASHSIZE)]);
	bucket = *save;
	while (bucket) {
		if (strncmp(bucket->name, name, len) == 0) {
			*save = bucket->next;
			return bucket->value;
		}
		save = &(bucket->next);
		bucket = bucket->next;
	}
	return NULL;
}

pop_params(params)
NODE *params;
{
	register NODE *np;

	for (np = params; np != NULL; np = np->rnode)
		pop_var(np->param);
}

NODE *
make_name(name, type)
char *name;
NODETYPE type;
{
	register char *p;
	register NODE *r;
	register int len;

	p = name;
	while (is_identchar(*p))
		p++;
	len = p - name;
	emalloc(r, NODE *, sizeof(NODE), "make_name");
	emalloc(r->param, char *, len + 1, "make_name");
	bcopy(name, r->param, len);
	r->param[len] = '\0';
	r->rnode = NULL;
	r->type = type;
	return (install(variables, name, r));
}

NODE *make_param(name)
char *name;
{
	NODE *r;

	r = make_name(name, Node_param_list);
	r->param_cnt = param_counter++;
	return r;
}

FILE *
nextfile()
{
	static int i = 1;
	static int files = 0;
	char *arg;
	char *cp;
	FILE *fp;
	extern NODE **assoc_lookup();

	for (; i < (int) (ARGC_node->lnode->numbr); i++) {
		arg = (*assoc_lookup(ARGV_node, tmp_number((AWKNUM) i)))->stptr;
		if (*arg == '\0')
			continue;
		cp = index(arg, '=');
		if (cp != NULL) {
			*cp++ = '\0';
			variable(arg)->var_value = make_string(cp, strlen(cp));
		} else {
			extern NODE *deref;

			files++;
			if (strcmp(arg, "-") == 0)
				fp = stdin;
			else
				fp = fopen(arg, "r");
			if (fp == NULL)
				fatal("cannot open file `%s' for reading (%s)",
					arg, sys_errlist[errno]);
				/* NOTREACHED */
			/* This is a kludge.  */
			deref = FILENAME_node->var_value;
			do_deref();
			FILENAME_node->var_value =
				make_string(arg, strlen(arg));
			FNR_node->var_value->numbr = 0.0;
			i++;
			return fp;
		}
	}
	if (files == 0) {
		files++;
		/* no args. -- use stdin */
		/* FILENAME is init'ed to "-" */
		/* FNR is init'ed to 0 */
		return stdin;
	}
	return NULL;
}