xref: /src/usr.bin/make/parse.c

/*	$NetBSD: parse.c,v 1.112 2006/03/31 20:30:46 christos Exp $	*/

/*
 * Copyright (c) 1988, 1989, 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * 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.
 */

/*
 * Copyright (c) 1989 by Berkeley Softworks
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * 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.
 */

#ifndef MAKE_NATIVE
static char rcsid[] = "$NetBSD: parse.c,v 1.112 2006/03/31 20:30:46 christos Exp $";
#else
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)parse.c	8.3 (Berkeley) 3/19/94";
#else
__RCSID("$NetBSD: parse.c,v 1.112 2006/03/31 20:30:46 christos Exp $");
#endif
#endif /* not lint */
#endif

/*-
 * parse.c --
 *	Functions to parse a makefile.
 *
 *	One function, Parse_Init, must be called before any functions
 *	in this module are used. After that, the function Parse_File is the
 *	main entry point and controls most of the other functions in this
 *	module.
 *
 *	Most important structures are kept in Lsts. Directories for
 *	the #include "..." function are kept in the 'parseIncPath' Lst, while
 *	those for the #include <...> are kept in the 'sysIncPath' Lst. The
 *	targets currently being defined are kept in the 'targets' Lst.
 *
 *	The variables 'fname' and 'lineno' are used to track the name
 *	of the current file and the line number in that file so that error
 *	messages can be more meaningful.
 *
 * Interface:
 *	Parse_Init	    	    Initialization function which must be
 *	    	  	    	    called before anything else in this module
 *	    	  	    	    is used.
 *
 *	Parse_End		    Cleanup the module
 *
 *	Parse_File	    	    Function used to parse a makefile. It must
 *	    	  	    	    be given the name of the file, which should
 *	    	  	    	    already have been opened, and a function
 *	    	  	    	    to call to read a character from the file.
 *
 *	Parse_IsVar	    	    Returns TRUE if the given line is a
 *	    	  	    	    variable assignment. Used by MainParseArgs
 *	    	  	    	    to determine if an argument is a target
 *	    	  	    	    or a variable assignment. Used internally
 *	    	  	    	    for pretty much the same thing...
 *
 *	Parse_Error	    	    Function called when an error occurs in
 *	    	  	    	    parsing. Used by the variable and
 *	    	  	    	    conditional modules.
 *	Parse_MainName	    	    Returns a Lst of the main target to create.
 */

#include <ctype.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>

#include "make.h"
#include "hash.h"
#include "dir.h"
#include "job.h"
#include "buf.h"
#include "pathnames.h"

/*
 * These values are returned by ParseEOF to tell Parse_File whether to
 * CONTINUE parsing, i.e. it had only reached the end of an include file,
 * or if it's DONE.
 */
#define	CONTINUE	1
#define	DONE		0
static Lst     	    targets;	/* targets we're working on */
#ifdef CLEANUP
static Lst     	    targCmds;	/* command lines for targets */
#endif
static Boolean	    inLine;	/* true if currently in a dependency
				 * line or its commands */
typedef struct {
    char *str;
    char *ptr;
} PTR;

static int	    fatals = 0;

static GNode	    *mainNode;	/* The main target to create. This is the
				 * first target on the first dependency
				 * line in the first makefile */
typedef struct IFile {
    char           *fname;	    /* name of previous file */
    int             lineno;	    /* saved line number */
    FILE *          F;		    /* the open stream */
    PTR *	    P;	    	    /* the char pointer */
} IFile;

static IFile	    curFile;


/*
 * Definitions for handling #include specifications
 */

static Lst      includes;  	/* stack of IFiles generated by
				 * #includes */
Lst         	parseIncPath;	/* list of directories for "..." includes */
Lst         	sysIncPath;	/* list of directories for <...> includes */
Lst         	defIncPath;	/* default directories for <...> includes */

/*-
 * specType contains the SPECial TYPE of the current target. It is
 * Not if the target is unspecial. If it *is* special, however, the children
 * are linked as children of the parent but not vice versa. This variable is
 * set in ParseDoDependency
 */
typedef enum {
    Begin,  	    /* .BEGIN */
    Default,	    /* .DEFAULT */
    End,    	    /* .END */
    Ignore,	    /* .IGNORE */
    Includes,	    /* .INCLUDES */
    Interrupt,	    /* .INTERRUPT */
    Libs,	    /* .LIBS */
    MFlags,	    /* .MFLAGS or .MAKEFLAGS */
    Main,	    /* .MAIN and we don't have anything user-specified to
		     * make */
    NoExport,	    /* .NOEXPORT */
    NoPath,	    /* .NOPATH */
    Not,	    /* Not special */
    NotParallel,    /* .NOTPARALLEL */
    Null,   	    /* .NULL */
    ExObjdir,	    /* .OBJDIR */
    Order,  	    /* .ORDER */
    Parallel,	    /* .PARALLEL */
    ExPath,	    /* .PATH */
    Phony,	    /* .PHONY */
#ifdef POSIX
    Posix,	    /* .POSIX */
#endif
    Precious,	    /* .PRECIOUS */
    ExShell,	    /* .SHELL */
    Silent,	    /* .SILENT */
    SingleShell,    /* .SINGLESHELL */
    Suffixes,	    /* .SUFFIXES */
    Wait,	    /* .WAIT */
    Attribute	    /* Generic attribute */
} ParseSpecial;

static ParseSpecial specType;
static int waiting;

#define	LPAREN	'('
#define	RPAREN	')'
/*
 * Predecessor node for handling .ORDER. Initialized to NILGNODE when .ORDER
 * seen, then set to each successive source on the line.
 */
static GNode	*predecessor;

/*
 * The parseKeywords table is searched using binary search when deciding
 * if a target or source is special. The 'spec' field is the ParseSpecial
 * type of the keyword ("Not" if the keyword isn't special as a target) while
 * the 'op' field is the operator to apply to the list of targets if the
 * keyword is used as a source ("0" if the keyword isn't special as a source)
 */
static struct {
    const char   *name;    	/* Name of keyword */
    ParseSpecial  spec;	    	/* Type when used as a target */
    int	    	  op;	    	/* Operator when used as a source */
} parseKeywords[] = {
{ ".BEGIN", 	  Begin,    	0 },
{ ".DEFAULT",	  Default,  	0 },
{ ".END",   	  End,	    	0 },
{ ".EXEC",	  Attribute,   	OP_EXEC },
{ ".IGNORE",	  Ignore,   	OP_IGNORE },
{ ".INCLUDES",	  Includes, 	0 },
{ ".INTERRUPT",	  Interrupt,	0 },
{ ".INVISIBLE",	  Attribute,   	OP_INVISIBLE },
{ ".JOIN",  	  Attribute,   	OP_JOIN },
{ ".LIBS",  	  Libs,	    	0 },
{ ".MADE",	  Attribute,	OP_MADE },
{ ".MAIN",	  Main,		0 },
{ ".MAKE",  	  Attribute,   	OP_MAKE },
{ ".MAKEFLAGS",	  MFlags,   	0 },
{ ".MFLAGS",	  MFlags,   	0 },
{ ".NOPATH",	  NoPath,	OP_NOPATH },
{ ".NOTMAIN",	  Attribute,   	OP_NOTMAIN },
{ ".NOTPARALLEL", NotParallel,	0 },
{ ".NO_PARALLEL", NotParallel,	0 },
{ ".NULL",  	  Null,	    	0 },
{ ".OBJDIR",	  ExObjdir,	0 },
{ ".OPTIONAL",	  Attribute,   	OP_OPTIONAL },
{ ".ORDER", 	  Order,    	0 },
{ ".PARALLEL",	  Parallel,	0 },
{ ".PATH",	  ExPath,	0 },
{ ".PHONY",	  Phony,	OP_PHONY },
#ifdef POSIX
{ ".POSIX",	  Posix,	0 },
#endif
{ ".PRECIOUS",	  Precious, 	OP_PRECIOUS },
{ ".RECURSIVE",	  Attribute,	OP_MAKE },
{ ".SHELL", 	  ExShell,    	0 },
{ ".SILENT",	  Silent,   	OP_SILENT },
{ ".SINGLESHELL", SingleShell,	0 },
{ ".SUFFIXES",	  Suffixes, 	0 },
{ ".USE",   	  Attribute,   	OP_USE },
{ ".USEBEFORE",   Attribute,   	OP_USEBEFORE },
{ ".WAIT",	  Wait, 	0 },
};

/*
 * Used by ParseDoSpecialSrc()
 */
typedef struct {
    int		op;
    char	*src;
    Lst		allsrc;
} SpecialSrc;

static int ParseIsEscaped(const char *, const char *);
static void ParseErrorInternal(char *, size_t, int, const char *, ...)
     __attribute__((__format__(__printf__, 4, 5)));
static void ParseVErrorInternal(char *, size_t, int, const char *, va_list)
     __attribute__((__format__(__printf__, 4, 0)));
static int ParseFindKeyword(char *);
static int ParseLinkSrc(ClientData, ClientData);
static int ParseDoOp(ClientData, ClientData);
static int ParseAddDep(ClientData, ClientData);
static int ParseDoSpecialSrc(ClientData, ClientData);
static void ParseDoSrc(int, char *, Lst, Boolean);
static int ParseFindMain(ClientData, ClientData);
static int ParseAddDir(ClientData, ClientData);
static int ParseClearPath(ClientData, ClientData);
static void ParseDoDependency(char *);
static int ParseAddCmd(ClientData, ClientData);
static inline int ParseReadc(void);
static void ParseUnreadc(int);
static void ParseHasCommands(ClientData);
static void ParseDoInclude(char *);
static void ParseSetParseFile(char *);
#ifdef SYSVINCLUDE
static void ParseTraditionalInclude(char *);
#endif
static int ParseEOF(int);
static char *ParseReadLine(void);
static char *ParseSkipLine(int, int);
static void ParseFinishLine(void);
static void ParseMark(GNode *);

extern int  maxJobs;


/*-
 *----------------------------------------------------------------------
 * ParseIsEscaped --
 *	Check if the current character is escaped on the current line
 *
 * Results:
 *	0 if the character is not backslash escaped, 1 otherwise
 *
 * Side Effects:
 *	None
 *----------------------------------------------------------------------
 */
static int
ParseIsEscaped(const char *line, const char *c)
{
    int active = 0;
    for (;;) {
	if (line == c)
	    return active;
	if (*--c != '\\')
	    return active;
	active = !active;
    }
}

/*-
 *----------------------------------------------------------------------
 * ParseFindKeyword --
 *	Look in the table of keywords for one matching the given string.
 *
 * Input:
 *	str		String to find
 *
 * Results:
 *	The index of the keyword, or -1 if it isn't there.
 *
 * Side Effects:
 *	None
 *----------------------------------------------------------------------
 */
static int
ParseFindKeyword(char *str)
{
    int    start, end, cur;
    int    diff;

    start = 0;
    end = (sizeof(parseKeywords)/sizeof(parseKeywords[0])) - 1;

    do {
	cur = start + ((end - start) / 2);
	diff = strcmp(str, parseKeywords[cur].name);

	if (diff == 0) {
	    return (cur);
	} else if (diff < 0) {
	    end = cur - 1;
	} else {
	    start = cur + 1;
	}
    } while (start <= end);
    return (-1);
}

/*-
 * ParseVErrorInternal  --
 *	Error message abort function for parsing. Prints out the context
 *	of the error (line number and file) as well as the message with
 *	two optional arguments.
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	"fatals" is incremented if the level is PARSE_FATAL.
 */
/* VARARGS */
static void
ParseVErrorInternal(char *cfname, size_t clineno, int type, const char *fmt,
    va_list ap)
{
	static Boolean fatal_warning_error_printed = FALSE;

	(void)fprintf(stderr, "%s: \"", progname);

	if (*cfname != '/') {
		char *cp;
		const char *dir;

		/*
		 * Nothing is more anoying than not knowing which Makefile
		 * is the culprit.
		 */
		dir = Var_Value(".PARSEDIR", VAR_GLOBAL, &cp);
		if (dir == NULL || *dir == '\0' ||
		    (*dir == '.' && dir[1] == '\0'))
			dir = Var_Value(".CURDIR", VAR_GLOBAL, &cp);
		if (dir == NULL)
			dir = ".";

		(void)fprintf(stderr, "%s/%s", dir, cfname);
	} else
		(void)fprintf(stderr, "%s", cfname);

	(void)fprintf(stderr, "\" line %d: ", (int)clineno);
	if (type == PARSE_WARNING)
		(void)fprintf(stderr, "warning: ");
	(void)vfprintf(stderr, fmt, ap);
	(void)fprintf(stderr, "\n");
	(void)fflush(stderr);
	if (type == PARSE_FATAL || parseWarnFatal)
		fatals += 1;
	if (parseWarnFatal && !fatal_warning_error_printed) {
		Error("parsing warnings being treated as errors");
		fatal_warning_error_printed = TRUE;
	}
}

/*-
 * ParseErrorInternal  --
 *	Error function
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	None
 */
/* VARARGS */
static void
ParseErrorInternal(char *cfname, size_t clineno, int type, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	ParseVErrorInternal(cfname, clineno, type, fmt, ap);
	va_end(ap);
}

/*-
 * Parse_Error  --
 *	External interface to ParseErrorInternal; uses the default filename
 *	Line number.
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	None
 */
/* VARARGS */
void
Parse_Error(int type, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	ParseVErrorInternal(curFile.fname, curFile.lineno, type, fmt, ap);
	va_end(ap);
}

/*-
 *---------------------------------------------------------------------
 * ParseLinkSrc  --
 *	Link the parent node to its new child. Used in a Lst_ForEach by
 *	ParseDoDependency. If the specType isn't 'Not', the parent
 *	isn't linked as a parent of the child.
 *
 * Input:
 *	pgnp		The parent node
 *	cgpn		The child node
 *
 * Results:
 *	Always = 0
 *
 * Side Effects:
 *	New elements are added to the parents list of cgn and the
 *	children list of cgn. the unmade field of pgn is updated
 *	to reflect the additional child.
 *---------------------------------------------------------------------
 */
static int
ParseLinkSrc(ClientData pgnp, ClientData cgnp)
{
    GNode          *pgn = (GNode *)pgnp;
    GNode          *cgn = (GNode *)cgnp;

    if ((pgn->type & OP_DOUBLEDEP) && !Lst_IsEmpty (pgn->cohorts))
	pgn = (GNode *)Lst_Datum(Lst_Last(pgn->cohorts));
    (void)Lst_AtEnd(pgn->children, (ClientData)cgn);
    if (specType == Not)
	    (void)Lst_AtEnd(cgn->parents, (ClientData)pgn);
    pgn->unmade += 1;
    if (DEBUG(PARSE)) {
	printf("# ParseLinkSrc: added child %s - %s\n", pgn->name, cgn->name);
	Targ_PrintNode(pgn, 0);
	Targ_PrintNode(cgn, 0);
    }
    return (0);
}

/*-
 *---------------------------------------------------------------------
 * ParseDoOp  --
 *	Apply the parsed operator to the given target node. Used in a
 *	Lst_ForEach call by ParseDoDependency once all targets have
 *	been found and their operator parsed. If the previous and new
 *	operators are incompatible, a major error is taken.
 *
 * Input:
 *	gnp		The node to which the operator is to be applied
 *	opp		The operator to apply
 *
 * Results:
 *	Always 0
 *
 * Side Effects:
 *	The type field of the node is altered to reflect any new bits in
 *	the op.
 *---------------------------------------------------------------------
 */
static int
ParseDoOp(ClientData gnp, ClientData opp)
{
    GNode          *gn = (GNode *)gnp;
    int             op = *(int *)opp;
    /*
     * If the dependency mask of the operator and the node don't match and
     * the node has actually had an operator applied to it before, and
     * the operator actually has some dependency information in it, complain.
     */
    if (((op & OP_OPMASK) != (gn->type & OP_OPMASK)) &&
	!OP_NOP(gn->type) && !OP_NOP(op))
    {
	Parse_Error(PARSE_FATAL, "Inconsistent operator for %s", gn->name);
	return (1);
    }

    if ((op == OP_DOUBLEDEP) && ((gn->type & OP_OPMASK) == OP_DOUBLEDEP)) {
	/*
	 * If the node was the object of a :: operator, we need to create a
	 * new instance of it for the children and commands on this dependency
	 * line. The new instance is placed on the 'cohorts' list of the
	 * initial one (note the initial one is not on its own cohorts list)
	 * and the new instance is linked to all parents of the initial
	 * instance.
	 */
	GNode	*cohort;

	/*
	 * Propagate copied bits to the initial node.  They'll be propagated
	 * back to the rest of the cohorts later.
	 */
	gn->type |= op & ~OP_OPMASK;

	cohort = Targ_NewGN(gn->name);
	/*
	 * Make the cohort invisible as well to avoid duplicating it into
	 * other variables. True, parents of this target won't tend to do
	 * anything with their local variables, but better safe than
	 * sorry. (I think this is pointless now, since the relevant list
	 * traversals will no longer see this node anyway. -mycroft)
	 */
	cohort->type = op | OP_INVISIBLE;
	(void)Lst_AtEnd(gn->cohorts, (ClientData)cohort);
	cohort->centurion = gn;
	gn->unmade_cohorts += 1;
    } else {
	/*
	 * We don't want to nuke any previous flags (whatever they were) so we
	 * just OR the new operator into the old
	 */
	gn->type |= op;
    }

    return (0);
}

/*-
 *---------------------------------------------------------------------
 * ParseAddDep  --
 *	Check if the pair of GNodes given needs to be synchronized.
 *	This has to be when two nodes are on different sides of a
 *	.WAIT directive.
 *
 * Results:
 *	Returns 1 if the two targets need to be ordered, 0 otherwise.
 *	If it returns 1, the search can stop
 *
 * Side Effects:
 *	A dependency can be added between the two nodes.
 *	The dependency is tagged for recursive addition to
 *	all children of sp.
 *
 *---------------------------------------------------------------------
 */
static int
ParseAddDep(ClientData pp, ClientData sp)
{
    GNode *p = (GNode *)pp;
    GNode *s = (GNode *)sp;

    if (DEBUG(PARSE))
	printf("ParseAddDep: %p(%s):%d %p(%s):%d\n",
		p, p->name, p->order, s, s->name, s->order);
    if (p->order >= s->order)
	return 1;

    /*
     * XXX: This can cause loops, and loops can cause unmade targets,
     * but checking is tedious, and the debugging output can show the
     * problem
     */
    (void)Lst_AtEnd(p->successors, (ClientData)s);
    (void)Lst_AtEnd(s->preds, (ClientData)p);
    (void)Lst_AtEnd(s->recpreds, (ClientData)p);
    if (DEBUG(PARSE)) {
	printf("# ParseAddDep: added .WAIT dependency %s - %s\n",
		p->name, s->name);
	Targ_PrintNode(p, 0);
	Targ_PrintNode(s, 0);
    }
    return 0;
}

/* -
 *---------------------------------------------------------------------
 * ParseDoSpecialSrc  --
 *	ParseDoSrc struck an unexpanded variable in a src.
 *	The most likely reason is a src that refers to .TARGET or
 *	.PREFIX so we get called to set those for each target
 *	and then call ParseDoSrc again to do the real work.
 *
 * Input:
 *	tp		A target GNode *
 *	sp		A SpecialSrc * which contains the args we need
 *			for ParseDoSrc.
 *
 * Results:
 *	Goodness
 *
 * Side Effects:
 *	The target GNode will have .TARGET and .PREFIX set, this seems
 *	harmless.
 */
static int
ParseDoSpecialSrc(ClientData tp, ClientData sp)
{
    GNode *tn = (GNode *)tp;
    GNode *gn;
    SpecialSrc *ss = (SpecialSrc *)sp;
    char *cp;
    char *cp2;
    char *pref;

    /*
     * If the target is a suffix rule, leave it alone.
     */
    if (Suff_IsTransform(tn->name)) {
	ParseDoSrc(ss->op, ss->src, ss->allsrc, FALSE); /* don't come back */
	return 0;
    }
    Var_Set(TARGET, tn->name, tn, 0);
    if ((pref = strrchr(tn->name, '/')))
	pref++;
    else
	pref = tn->name;
    if ((cp2 = strchr(pref, '.')) > pref) {
	cp = estrdup(pref);
	cp[cp2 - pref] = '\0';
	Var_Set(PREFIX, cp, tn, 0);
	free(cp);
    } else
	Var_Set(PREFIX, pref, tn, 0);
    cp = Var_Subst(NULL, ss->src, tn, FALSE);
    if (strchr(cp, '$')) {
	Parse_Error(PARSE_WARNING, "Cannot resolve '%s' here", ss->src);
	ParseDoSrc(ss->op, ss->src, ss->allsrc, FALSE); /* don't come back */
	return 1;			/* stop list traversal */
    }
    /*
     * We don't want to make every target dependent on sources for
     * other targets.  This is the bit of ParseDoSrc which is relevant.
     * The main difference is we don't link the resolved src to all targets.
     */
    gn = Targ_FindNode(cp, TARG_CREATE);
    if (ss->op) {
	gn->type |= ss->op;
    } else {
	ParseLinkSrc((ClientData)tn, (ClientData)gn);
    }
    if (DEBUG(PARSE))
	printf("ParseDoSpecialSrc: set %p(%s):%d (was %d)\n",
		gn, gn->name, waiting, gn->order);
    gn->order = waiting;
    (void)Lst_AtEnd(ss->allsrc, (ClientData)gn);
    if (waiting) {
	Lst_ForEach(ss->allsrc, ParseAddDep, (ClientData)gn);
    }
    return 0;
}


/*-
 *---------------------------------------------------------------------
 * ParseDoSrc  --
 *	Given the name of a source, figure out if it is an attribute
 *	and apply it to the targets if it is. Else decide if there is
 *	some attribute which should be applied *to* the source because
 *	of some special target and apply it if so. Otherwise, make the
 *	source be a child of the targets in the list 'targets'
 *
 * Input:
 *	tOp		operator (if any) from special targets
 *	src		name of the source to handle
 *	allsrc		List of all sources to wait for
 *	resolve		boolean - should we try and resolve .TARGET refs.
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	Operator bits may be added to the list of targets or to the source.
 *	The targets may have a new source added to their lists of children.
 *---------------------------------------------------------------------
 */
static void
ParseDoSrc(int tOp, char *src, Lst allsrc, Boolean resolve)
{
    GNode	*gn = NULL;

    if (*src == '.' && isupper ((unsigned char)src[1])) {
	int keywd = ParseFindKeyword(src);
	if (keywd != -1) {
	    int op = parseKeywords[keywd].op;
	    if (op != 0) {
		Lst_ForEach(targets, ParseDoOp, (ClientData)&op);
		return;
	    }
	    if (parseKeywords[keywd].spec == Wait) {
		waiting++;
		return;
	    }
	}
    }

    switch (specType) {
    case Main:
	/*
	 * If we have noted the existence of a .MAIN, it means we need
	 * to add the sources of said target to the list of things
	 * to create. The string 'src' is likely to be free, so we
	 * must make a new copy of it. Note that this will only be
	 * invoked if the user didn't specify a target on the command
	 * line. This is to allow #ifmake's to succeed, or something...
	 */
	(void)Lst_AtEnd(create, (ClientData)estrdup(src));
	/*
	 * Add the name to the .TARGETS variable as well, so the user cna
	 * employ that, if desired.
	 */
	Var_Append(".TARGETS", src, VAR_GLOBAL);
	return;

    case Order:
	/*
	 * Create proper predecessor/successor links between the previous
	 * source and the current one.
	 */
	gn = Targ_FindNode(src, TARG_CREATE);
	if (predecessor != NILGNODE) {
	    (void)Lst_AtEnd(predecessor->successors, (ClientData)gn);
	    (void)Lst_AtEnd(gn->preds, (ClientData)predecessor);
	    if (DEBUG(PARSE)) {
		printf("# ParseDoSrc: added Order dependency %s - %s\n",
			predecessor->name, gn->name);
		Targ_PrintNode(predecessor, 0);
		Targ_PrintNode(gn, 0);
	    }
	}
	/*
	 * The current source now becomes the predecessor for the next one.
	 */
	predecessor = gn;
	break;

    default:
	/*
	 * If the source is not an attribute, we need to find/create
	 * a node for it. After that we can apply any operator to it
	 * from a special target or link it to its parents, as
	 * appropriate.
	 *
	 * In the case of a source that was the object of a :: operator,
	 * the attribute is applied to all of its instances (as kept in
	 * the 'cohorts' list of the node) or all the cohorts are linked
	 * to all the targets.
	 */
	if (resolve && strchr(src, '$')) {
	    SpecialSrc ss;

	    ss.op = tOp;
	    ss.src = src;
	    ss.allsrc = allsrc;

	    /*
	     * If src cannot be fully resolved, we'll be called again
	     * with resolve==FALSE.
	     */
	    Lst_ForEach(targets, ParseDoSpecialSrc, (ClientData)&ss);
	    return;
	}
	gn = Targ_FindNode(src, TARG_CREATE);
	if (tOp) {
	    gn->type |= tOp;
	} else {
	    Lst_ForEach(targets, ParseLinkSrc, (ClientData)gn);
	}
	break;
    }

    if (DEBUG(PARSE))
	printf("ParseDoSrc: set %p(%s):%d (was %d)\n",
		gn, gn->name, waiting, gn->order);
    gn->order = waiting;
    (void)Lst_AtEnd(allsrc, (ClientData)gn);
    if (waiting) {
	Lst_ForEach(allsrc, ParseAddDep, (ClientData)gn);
    }
}

/*-
 *-----------------------------------------------------------------------
 * ParseFindMain --
 *	Find a real target in the list and set it to be the main one.
 *	Called by ParseDoDependency when a main target hasn't been found
 *	yet.
 *
 * Input:
 *	gnp		Node to examine
 *
 * Results:
 *	0 if main not found yet, 1 if it is.
 *
 * Side Effects:
 *	mainNode is changed and Targ_SetMain is called.
 *
 *-----------------------------------------------------------------------
 */
static int
ParseFindMain(ClientData gnp, ClientData dummy)
{
    GNode   	  *gn = (GNode *)gnp;
    if ((gn->type & OP_NOTARGET) == 0) {
	mainNode = gn;
	Targ_SetMain(gn);
	return (dummy ? 1 : 1);
    } else {
	return (dummy ? 0 : 0);
    }
}

/*-
 *-----------------------------------------------------------------------
 * ParseAddDir --
 *	Front-end for Dir_AddDir to make sure Lst_ForEach keeps going
 *
 * Results:
 *	=== 0
 *
 * Side Effects:
 *	See Dir_AddDir.
 *
 *-----------------------------------------------------------------------
 */
static int
ParseAddDir(ClientData path, ClientData name)
{
    (void)Dir_AddDir((Lst) path, (char *)name);
    return(0);
}

/*-
 *-----------------------------------------------------------------------
 * ParseClearPath --
 *	Front-end for Dir_ClearPath to make sure Lst_ForEach keeps going
 *
 * Results:
 *	=== 0
 *
 * Side Effects:
 *	See Dir_ClearPath
 *
 *-----------------------------------------------------------------------
 */
static int
ParseClearPath(ClientData path, ClientData dummy)
{
    Dir_ClearPath((Lst) path);
    return(dummy ? 0 : 0);
}

/*-
 *---------------------------------------------------------------------
 * ParseDoDependency  --
 *	Parse the dependency line in line.
 *
 * Input:
 *	line		the line to parse
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	The nodes of the sources are linked as children to the nodes of the
 *	targets. Some nodes may be created.
 *
 *	We parse a dependency line by first extracting words from the line and
 * finding nodes in the list of all targets with that name. This is done
 * until a character is encountered which is an operator character. Currently
 * these are only ! and :. At this point the operator is parsed and the
 * pointer into the line advanced until the first source is encountered.
 * 	The parsed operator is applied to each node in the 'targets' list,
 * which is where the nodes found for the targets are kept, by means of
 * the ParseDoOp function.
 *	The sources are read in much the same way as the targets were except
 * that now they are expanded using the wildcarding scheme of the C-Shell
 * and all instances of the resulting words in the list of all targets
 * are found. Each of the resulting nodes is then linked to each of the
 * targets as one of its children.
 *	Certain targets are handled specially. These are the ones detailed
 * by the specType variable.
 *	The storing of transformation rules is also taken care of here.
 * A target is recognized as a transformation rule by calling
 * Suff_IsTransform. If it is a transformation rule, its node is gotten
 * from the suffix module via Suff_AddTransform rather than the standard
 * Targ_FindNode in the target module.
 *---------------------------------------------------------------------
 */
static void
ParseDoDependency(char *line)
{
    char  	   *cp;		/* our current position */
    GNode 	   *gn = NULL;	/* a general purpose temporary node */
    int             op;		/* the operator on the line */
    char            savec;	/* a place to save a character */
    Lst    	    paths;   	/* List of search paths to alter when parsing
				 * a list of .PATH targets */
    int	    	    tOp;    	/* operator from special target */
    Lst	    	    sources;	/* list of archive source names after
				 * expansion */
    Lst 	    curTargs;	/* list of target names to be found and added
				 * to the targets list */
    Lst		    curSrcs;	/* list of sources in order */
    char	   *lstart = line;
    Boolean	    hasWait;	/* is .WAIT present in srcs */

    tOp = 0;

    specType = Not;
    waiting = 0;
    paths = (Lst)NULL;

    curTargs = Lst_Init(FALSE);
    curSrcs = Lst_Init(FALSE);

    do {
	for (cp = line;
	     *cp && (ParseIsEscaped(lstart, cp) ||
	     (!isspace ((unsigned char)*cp) &&
	     (*cp != '!') && (*cp != ':') && (*cp != LPAREN)));
	     cp++)
	{
	    if (*cp == '$') {
		/*
		 * Must be a dynamic source (would have been expanded
		 * otherwise), so call the Var module to parse the puppy
		 * so we can safely advance beyond it...There should be
		 * no errors in this, as they would have been discovered
		 * in the initial Var_Subst and we wouldn't be here.
		 */
		int 	length;
		Boolean	freeIt;
		char	*result;

		result=Var_Parse(cp, VAR_CMD, TRUE, &length, &freeIt);

		if (freeIt) {
		    free(result);
		}
		cp += length-1;
	    }
	    continue;
	}
	if (!ParseIsEscaped(lstart, cp) && *cp == LPAREN) {
	    /*
	     * Archives must be handled specially to make sure the OP_ARCHV
	     * flag is set in their 'type' field, for one thing, and because
	     * things like "archive(file1.o file2.o file3.o)" are permissible.
	     * Arch_ParseArchive will set 'line' to be the first non-blank
	     * after the archive-spec. It creates/finds nodes for the members
	     * and places them on the given list, returning SUCCESS if all
	     * went well and FAILURE if there was an error in the
	     * specification. On error, line should remain untouched.
	     */
	    if (Arch_ParseArchive(&line, targets, VAR_CMD) != SUCCESS) {
		Parse_Error(PARSE_FATAL,
			     "Error in archive specification: \"%s\"", line);
		goto out;
	    } else {
		continue;
	    }
	}
	savec = *cp;

	if (!*cp) {
	    /*
	     * Ending a dependency line without an operator is a Bozo
	     * no-no.  As a heuristic, this is also often triggered by
	     * undetected conflicts from cvs/rcs merges.
	     */
	    if ((strncmp(line, "<<<<<<", 6) == 0) ||
		(strncmp(line, "======", 6) == 0) ||
		(strncmp(line, ">>>>>>", 6) == 0))
		Parse_Error(PARSE_FATAL,
		    "Makefile appears to contain unresolved cvs/rcs/??? merge conflicts");
	    else
		Parse_Error(PARSE_FATAL, "Need an operator");
	    goto out;
	}
	*cp = '\0';
	/*
	 * Have a word in line. See if it's a special target and set
	 * specType to match it.
	 */
	if (*line == '.' && isupper ((unsigned char)line[1])) {
	    /*
	     * See if the target is a special target that must have it
	     * or its sources handled specially.
	     */
	    int keywd = ParseFindKeyword(line);
	    if (keywd != -1) {
		if (specType == ExPath && parseKeywords[keywd].spec != ExPath) {
		    Parse_Error(PARSE_FATAL, "Mismatched special targets");
		    goto out;
		}

		specType = parseKeywords[keywd].spec;
		tOp = parseKeywords[keywd].op;

		/*
		 * Certain special targets have special semantics:
		 *	.PATH		Have to set the dirSearchPath
		 *			variable too
		 *	.MAIN		Its sources are only used if
		 *			nothing has been specified to
		 *			create.
		 *	.DEFAULT    	Need to create a node to hang
		 *			commands on, but we don't want
		 *			it in the graph, nor do we want
		 *			it to be the Main Target, so we
		 *			create it, set OP_NOTMAIN and
		 *			add it to the list, setting
		 *			DEFAULT to the new node for
		 *			later use. We claim the node is
		 *	    	    	A transformation rule to make
		 *	    	    	life easier later, when we'll
		 *	    	    	use Make_HandleUse to actually
		 *	    	    	apply the .DEFAULT commands.
		 *	.PHONY		The list of targets
		 *	.NOPATH		Don't search for file in the path
		 *	.BEGIN
		 *	.END
		 *	.INTERRUPT  	Are not to be considered the
		 *			main target.
		 *  	.NOTPARALLEL	Make only one target at a time.
		 *  	.SINGLESHELL	Create a shell for each command.
		 *  	.ORDER	    	Must set initial predecessor to NIL
		 */
		switch (specType) {
		    case ExPath:
			if (paths == NULL) {
			    paths = Lst_Init(FALSE);
			}
			(void)Lst_AtEnd(paths, (ClientData)dirSearchPath);
			break;
		    case Main:
			if (!Lst_IsEmpty(create)) {
			    specType = Not;
			}
			break;
		    case Begin:
		    case End:
		    case Interrupt:
			gn = Targ_FindNode(line, TARG_CREATE);
			gn->type |= OP_NOTMAIN|OP_SPECIAL;
			(void)Lst_AtEnd(targets, (ClientData)gn);
			break;
		    case Default:
			gn = Targ_NewGN(".DEFAULT");
			gn->type |= (OP_NOTMAIN|OP_TRANSFORM);
			(void)Lst_AtEnd(targets, (ClientData)gn);
			DEFAULT = gn;
			break;
		    case NotParallel:
			not_parallel = 1;
			break;
		    case SingleShell:
			compatMake = TRUE;
			break;
		    case Order:
			predecessor = NILGNODE;
			break;
		    default:
			break;
		}
	    } else if (strncmp(line, ".PATH", 5) == 0) {
		/*
		 * .PATH<suffix> has to be handled specially.
		 * Call on the suffix module to give us a path to
		 * modify.
		 */
		Lst 	path;

		specType = ExPath;
		path = Suff_GetPath(&line[5]);
		if (path == NILLST) {
		    Parse_Error(PARSE_FATAL,
				 "Suffix '%s' not defined (yet)",
				 &line[5]);
		    goto out;
		} else {
		    if (paths == (Lst)NULL) {
			paths = Lst_Init(FALSE);
		    }
		    (void)Lst_AtEnd(paths, (ClientData)path);
		}
	    }
	}

	/*
	 * Have word in line. Get or create its node and stick it at
	 * the end of the targets list
	 */
	if ((specType == Not) && (*line != '\0')) {
	    if (Dir_HasWildcards(line)) {
		/*
		 * Targets are to be sought only in the current directory,
		 * so create an empty path for the thing. Note we need to
		 * use Dir_Destroy in the destruction of the path as the
		 * Dir module could have added a directory to the path...
		 */
		Lst	    emptyPath = Lst_Init(FALSE);

		Dir_Expand(line, emptyPath, curTargs);

		Lst_Destroy(emptyPath, Dir_Destroy);
	    } else {
		/*
		 * No wildcards, but we want to avoid code duplication,
		 * so create a list with the word on it.
		 */
		(void)Lst_AtEnd(curTargs, (ClientData)line);
	    }

	    while(!Lst_IsEmpty(curTargs)) {
		char	*targName = (char *)Lst_DeQueue(curTargs);

		if (!Suff_IsTransform (targName)) {
		    gn = Targ_FindNode(targName, TARG_CREATE);
		} else {
		    gn = Suff_AddTransform(targName);
		}

		(void)Lst_AtEnd(targets, (ClientData)gn);
	    }
	} else if (specType == ExPath && *line != '.' && *line != '\0') {
	    Parse_Error(PARSE_WARNING, "Extra target (%s) ignored", line);
	}

	*cp = savec;
	/*
	 * If it is a special type and not .PATH, it's the only target we
	 * allow on this line...
	 */
	if (specType != Not && specType != ExPath) {
	    Boolean warn = FALSE;

	    while (*cp && (ParseIsEscaped(lstart, cp) ||
		((*cp != '!') && (*cp != ':')))) {
		if (ParseIsEscaped(lstart, cp) ||
		    (*cp != ' ' && *cp != '\t')) {
		    warn = TRUE;
		}
		cp++;
	    }
	    if (warn) {
		Parse_Error(PARSE_WARNING, "Extra target ignored");
	    }
	} else {
	    while (*cp && isspace ((unsigned char)*cp)) {
		cp++;
	    }
	}
	line = cp;
    } while (*line && (ParseIsEscaped(lstart, line) ||
	((*line != '!') && (*line != ':'))));

    /*
     * Don't need the list of target names anymore...
     */
    Lst_Destroy(curTargs, NOFREE);
    curTargs = NULL;

    if (!Lst_IsEmpty(targets)) {
	switch(specType) {
	    default:
		Parse_Error(PARSE_WARNING, "Special and mundane targets don't mix. Mundane ones ignored");
		break;
	    case Default:
	    case Begin:
	    case End:
	    case Interrupt:
		/*
		 * These four create nodes on which to hang commands, so
		 * targets shouldn't be empty...
		 */
	    case Not:
		/*
		 * Nothing special here -- targets can be empty if it wants.
		 */
		break;
	}
    }

    /*
     * Have now parsed all the target names. Must parse the operator next. The
     * result is left in  op .
     */
    if (*cp == '!') {
	op = OP_FORCE;
    } else if (*cp == ':') {
	if (cp[1] == ':') {
	    op = OP_DOUBLEDEP;
	    cp++;
	} else {
	    op = OP_DEPENDS;
	}
    } else {
	Parse_Error(PARSE_FATAL, "Missing dependency operator");
	goto out;
    }

    cp++;			/* Advance beyond operator */

    Lst_ForEach(targets, ParseDoOp, (ClientData)&op);

    /*
     * Get to the first source
     */
    while (*cp && isspace ((unsigned char)*cp)) {
	cp++;
    }
    line = cp;

    /*
     * Several special targets take different actions if present with no
     * sources:
     *	a .SUFFIXES line with no sources clears out all old suffixes
     *	a .PRECIOUS line makes all targets precious
     *	a .IGNORE line ignores errors for all targets
     *	a .SILENT line creates silence when making all targets
     *	a .PATH removes all directories from the search path(s).
     */
    if (!*line) {
	switch (specType) {
	    case Suffixes:
		Suff_ClearSuffixes();
		break;
	    case Precious:
		allPrecious = TRUE;
		break;
	    case Ignore:
		ignoreErrors = TRUE;
		break;
	    case Silent:
		beSilent = TRUE;
		break;
	    case ExPath:
		Lst_ForEach(paths, ParseClearPath, (ClientData)NULL);
		Dir_SetPATH();
		break;
#ifdef POSIX
            case Posix:
                Var_Set("%POSIX", "1003.2", VAR_GLOBAL, 0);
                break;
#endif
	    default:
		break;
	}
    } else if (specType == MFlags) {
	/*
	 * Call on functions in main.c to deal with these arguments and
	 * set the initial character to a null-character so the loop to
	 * get sources won't get anything
	 */
	Main_ParseArgLine(line);
	*line = '\0';
    } else if (specType == ExShell) {
	if (Job_ParseShell(line) != SUCCESS) {
	    Parse_Error(PARSE_FATAL, "improper shell specification");
	    goto out;
	}
	*line = '\0';
    } else if ((specType == NotParallel) || (specType == SingleShell)) {
	*line = '\0';
    }

    /*
     * NOW GO FOR THE SOURCES
     */
    if ((specType == Suffixes) || (specType == ExPath) ||
	(specType == Includes) || (specType == Libs) ||
	(specType == Null) || (specType == ExObjdir))
    {
	while (*line) {
	    /*
	     * If the target was one that doesn't take files as its sources
	     * but takes something like suffixes, we take each
	     * space-separated word on the line as a something and deal
	     * with it accordingly.
	     *
	     * If the target was .SUFFIXES, we take each source as a
	     * suffix and add it to the list of suffixes maintained by the
	     * Suff module.
	     *
	     * If the target was a .PATH, we add the source as a directory
	     * to search on the search path.
	     *
	     * If it was .INCLUDES, the source is taken to be the suffix of
	     * files which will be #included and whose search path should
	     * be present in the .INCLUDES variable.
	     *
	     * If it was .LIBS, the source is taken to be the suffix of
	     * files which are considered libraries and whose search path
	     * should be present in the .LIBS variable.
	     *
	     * If it was .NULL, the source is the suffix to use when a file
	     * has no valid suffix.
	     *
	     * If it was .OBJDIR, the source is a new definition for .OBJDIR,
	     * and will cause make to do a new chdir to that path.
	     */
	    while (*cp && !isspace ((unsigned char)*cp)) {
		cp++;
	    }
	    savec = *cp;
	    *cp = '\0';
	    switch (specType) {
		case Suffixes:
		    Suff_AddSuffix(line, &mainNode);
		    break;
		case ExPath:
		    Lst_ForEach(paths, ParseAddDir, (ClientData)line);
		    break;
		case Includes:
		    Suff_AddInclude(line);
		    break;
		case Libs:
		    Suff_AddLib(line);
		    break;
		case Null:
		    Suff_SetNull(line);
		    break;
		case ExObjdir:
		    Main_SetObjdir(line);
		    break;
		default:
		    break;
	    }
	    *cp = savec;
	    if (savec != '\0') {
		cp++;
	    }
	    while (*cp && isspace ((unsigned char)*cp)) {
		cp++;
	    }
	    line = cp;
	}
	if (paths) {
	    Lst_Destroy(paths, NOFREE);
	}
	if (specType == ExPath)
	    Dir_SetPATH();
    } else {
	/*
	 * We don't need ParseDoSpecialSrc unless .WAIT is present.
	 */
	hasWait = (strstr(line, ".WAIT") != NULL);

	while (*line) {
	    /*
	     * The targets take real sources, so we must beware of archive
	     * specifications (i.e. things with left parentheses in them)
	     * and handle them accordingly.
	     */
	    while (*cp && !isspace ((unsigned char)*cp)) {
		if ((*cp == LPAREN) && (cp > line) && (cp[-1] != '$')) {
		    /*
		     * Only stop for a left parenthesis if it isn't at the
		     * start of a word (that'll be for variable changes
		     * later) and isn't preceded by a dollar sign (a dynamic
		     * source).
		     */
		    break;
		} else {
		    cp++;
		}
	    }

	    if (*cp == LPAREN) {
		sources = Lst_Init(FALSE);
		if (Arch_ParseArchive(&line, sources, VAR_CMD) != SUCCESS) {
		    Parse_Error(PARSE_FATAL,
				 "Error in source archive spec \"%s\"", line);
		    goto out;
		}

		while (!Lst_IsEmpty (sources)) {
		    gn = (GNode *)Lst_DeQueue(sources);
		    ParseDoSrc(tOp, gn->name, curSrcs, hasWait);
		}
		Lst_Destroy(sources, NOFREE);
		cp = line;
	    } else {
		if (*cp) {
		    *cp = '\0';
		    cp += 1;
		}

		ParseDoSrc(tOp, line, curSrcs, hasWait);
	    }
	    while (*cp && isspace ((unsigned char)*cp)) {
		cp++;
	    }
	    line = cp;
	}
    }

    if (mainNode == NILGNODE) {
	/*
	 * If we have yet to decide on a main target to make, in the
	 * absence of any user input, we want the first target on
	 * the first dependency line that is actually a real target
	 * (i.e. isn't a .USE or .EXEC rule) to be made.
	 */
	Lst_ForEach(targets, ParseFindMain, (ClientData)0);
    }

out:
    if (curTargs)
	    Lst_Destroy(curTargs, NOFREE);
    /*
     * Finally, destroy the list of sources
     */
    Lst_Destroy(curSrcs, NOFREE);
}

/*-
 *---------------------------------------------------------------------
 * Parse_IsVar  --
 *	Return TRUE if the passed line is a variable assignment. A variable
 *	assignment consists of a single word followed by optional whitespace
 *	followed by either a += or an = operator.
 *	This function is used both by the Parse_File function and main when
 *	parsing the command-line arguments.
 *
 * Input:
 *	line		the line to check
 *
 * Results:
 *	TRUE if it is. FALSE if it ain't
 *
 * Side Effects:
 *	none
 *---------------------------------------------------------------------
 */
Boolean
Parse_IsVar(char *line)
{
    Boolean wasSpace = FALSE;	/* set TRUE if found a space */
    Boolean haveName = FALSE;	/* Set TRUE if have a variable name */
    int level = 0;
#define ISEQOPERATOR(c) \
	(((c) == '+') || ((c) == ':') || ((c) == '?') || ((c) == '!'))

    /*
     * Skip to variable name
     */
    for (;(*line == ' ') || (*line == '\t'); line++)
	continue;

    for (; *line != '=' || level != 0; line++)
	switch (*line) {
	case '\0':
	    /*
	     * end-of-line -- can't be a variable assignment.
	     */
	    return FALSE;

	case ' ':
	case '\t':
	    /*
	     * there can be as much white space as desired so long as there is
	     * only one word before the operator
	     */
	    wasSpace = TRUE;
	    break;

	case LPAREN:
	case '{':
	    level++;
	    break;

	case '}':
	case RPAREN:
	    level--;
	    break;

	default:
	    if (wasSpace && haveName) {
		    if (ISEQOPERATOR(*line)) {
			/*
			 * We must have a finished word
			 */
			if (level != 0)
			    return FALSE;

			/*
			 * When an = operator [+?!:] is found, the next
			 * character must be an = or it ain't a valid
			 * assignment.
			 */
			if (line[1] == '=')
			    return haveName;
#ifdef SUNSHCMD
			/*
			 * This is a shell command
			 */
			if (strncmp(line, ":sh", 3) == 0)
			    return haveName;
#endif
		    }
		    /*
		     * This is the start of another word, so not assignment.
		     */
		    return FALSE;
	    }
	    else {
		haveName = TRUE;
		wasSpace = FALSE;
	    }
	    break;
	}

    return haveName;
}

/*-
 *---------------------------------------------------------------------
 * Parse_DoVar  --
 *	Take the variable assignment in the passed line and do it in the
 *	global context.
 *
 *	Note: There is a lexical ambiguity with assignment modifier characters
 *	in variable names. This routine interprets the character before the =
 *	as a modifier. Therefore, an assignment like
 *	    C++=/usr/bin/CC
 *	is interpreted as "C+ +=" instead of "C++ =".
 *
 * Input:
 *	line		a line guaranteed to be a variable assignment.
 *			This reduces error checks
 *	ctxt		Context in which to do the assignment
 *
 * Results:
 *	none
 *
 * Side Effects:
 *	the variable structure of the given variable name is altered in the
 *	global context.
 *---------------------------------------------------------------------
 */
void
Parse_DoVar(char *line, GNode *ctxt)
{
    char	   *cp;	/* pointer into line */
    enum {
	VAR_SUBST, VAR_APPEND, VAR_SHELL, VAR_NORMAL
    }	    	    type;   	/* Type of assignment */
    char            *opc;	/* ptr to operator character to
				 * null-terminate the variable name */
    Boolean	   freeCp = FALSE; /* TRUE if cp needs to be freed,
				    * i.e. if any variable expansion was
				    * performed */
    /*
     * Avoid clobbered variable warnings by forcing the compiler
     * to ``unregister'' variables
     */
#if __GNUC__
    (void) &cp;
    (void) &line;
#endif

    /*
     * Skip to variable name
     */
    while ((*line == ' ') || (*line == '\t')) {
	line++;
    }

    /*
     * Skip to operator character, nulling out whitespace as we go
     */
    for (cp = line + 1; *cp != '='; cp++) {
	if (isspace ((unsigned char)*cp)) {
	    *cp = '\0';
	}
    }
    opc = cp-1;		/* operator is the previous character */
    *cp++ = '\0';	/* nuke the = */

    /*
     * Check operator type
     */
    switch (*opc) {
	case '+':
	    type = VAR_APPEND;
	    *opc = '\0';
	    break;

	case '?':
	    /*
	     * If the variable already has a value, we don't do anything.
	     */
	    *opc = '\0';
	    if (Var_Exists(line, ctxt)) {
		return;
	    } else {
		type = VAR_NORMAL;
	    }
	    break;

	case ':':
	    type = VAR_SUBST;
	    *opc = '\0';
	    break;

	case '!':
	    type = VAR_SHELL;
	    *opc = '\0';
	    break;

	default:
#ifdef SUNSHCMD
	    while (opc > line && *opc != ':')
		opc--;

	    if (strncmp(opc, ":sh", 3) == 0) {
		type = VAR_SHELL;
		*opc = '\0';
		break;
	    }
#endif
	    type = VAR_NORMAL;
	    break;
    }

    while (isspace ((unsigned char)*cp)) {
	cp++;
    }

    if (type == VAR_APPEND) {
	Var_Append(line, cp, ctxt);
    } else if (type == VAR_SUBST) {
	/*
	 * Allow variables in the old value to be undefined, but leave their
	 * invocation alone -- this is done by forcing oldVars to be false.
	 * XXX: This can cause recursive variables, but that's not hard to do,
	 * and this allows someone to do something like
	 *
	 *  CFLAGS = $(.INCLUDES)
	 *  CFLAGS := -I.. $(CFLAGS)
	 *
	 * And not get an error.
	 */
	Boolean	  oldOldVars = oldVars;

	oldVars = FALSE;

	/*
	 * make sure that we set the variable the first time to nothing
	 * so that it gets substituted!
	 */
	if (!Var_Exists(line, ctxt))
	    Var_Set(line, "", ctxt, 0);

	cp = Var_Subst(NULL, cp, ctxt, FALSE);
	oldVars = oldOldVars;
	freeCp = TRUE;

	Var_Set(line, cp, ctxt, 0);
    } else if (type == VAR_SHELL) {
	char *res;
	const char *err;

	if (strchr(cp, '$') != NULL) {
	    /*
	     * There's a dollar sign in the command, so perform variable
	     * expansion on the whole thing. The resulting string will need
	     * freeing when we're done, so set freeCmd to TRUE.
	     */
	    cp = Var_Subst(NULL, cp, VAR_CMD, TRUE);
	    freeCp = TRUE;
	}

	res = Cmd_Exec(cp, &err);
	Var_Set(line, res, ctxt, 0);
	free(res);

	if (err)
	    Parse_Error(PARSE_WARNING, err, cp);
    } else {
	/*
	 * Normal assignment -- just do it.
	 */
	Var_Set(line, cp, ctxt, 0);
    }
    if (strcmp(line, MAKEOVERRIDES) == 0)
	Main_ExportMAKEFLAGS(FALSE);	/* re-export MAKEFLAGS */
    else if (strcmp(line, ".CURDIR") == 0) {
	/*
	 * Somone is being (too?) clever...
	 * Let's pretend they know what they are doing and
	 * re-initialize the 'cur' Path.
	 */
	Dir_InitCur(cp);
	Dir_SetPATH();
    }
    if (freeCp)
	free(cp);
}


/*-
 * ParseAddCmd  --
 *	Lst_ForEach function to add a command line to all targets
 *
 * Input:
 *	gnp		the node to which the command is to be added
 *	cmd		the command to add
 *
 * Results:
 *	Always 0
 *
 * Side Effects:
 *	A new element is added to the commands list of the node.
 */
static int
ParseAddCmd(ClientData gnp, ClientData cmd)
{
    GNode *gn = (GNode *)gnp;
    /* if target already supplied, ignore commands */
    if ((gn->type & OP_DOUBLEDEP) && !Lst_IsEmpty (gn->cohorts))
	gn = (GNode *)Lst_Datum(Lst_Last(gn->cohorts));
    if (!(gn->type & OP_HAS_COMMANDS)) {
	(void)Lst_AtEnd(gn->commands, cmd);
	ParseMark(gn);
    } else {
#ifdef notyet
	/* XXX: We cannot do this until we fix the tree */
	(void)Lst_AtEnd(gn->commands, cmd);
	Parse_Error(PARSE_WARNING,
		     "overriding commands for target \"%s\"; "
		     "previous commands defined at %s: %d ignored",
		     gn->name, gn->fname, gn->lineno);
#else
	Parse_Error(PARSE_WARNING,
		     "duplicate script for target \"%s\" ignored",
		     gn->name);
	ParseErrorInternal(gn->fname, gn->lineno, PARSE_WARNING,
			    "using previous script for \"%s\" defined here",
			    gn->name);
#endif
    }
    return(0);
}

/*-
 *-----------------------------------------------------------------------
 * ParseHasCommands --
 *	Callback procedure for Parse_File when destroying the list of
 *	targets on the last dependency line. Marks a target as already
 *	having commands if it does, to keep from having shell commands
 *	on multiple dependency lines.
 *
 * Input:
 *	gnp		Node to examine
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	OP_HAS_COMMANDS may be set for the target.
 *
 *-----------------------------------------------------------------------
 */
static void
ParseHasCommands(ClientData gnp)
{
    GNode *gn = (GNode *)gnp;
    if (!Lst_IsEmpty(gn->commands)) {
	gn->type |= OP_HAS_COMMANDS;
    }
}

/*-
 *-----------------------------------------------------------------------
 * Parse_AddIncludeDir --
 *	Add a directory to the path searched for included makefiles
 *	bracketed by double-quotes. Used by functions in main.c
 *
 * Input:
 *	dir		The name of the directory to add
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	The directory is appended to the list.
 *
 *-----------------------------------------------------------------------
 */
void
Parse_AddIncludeDir(char *dir)
{
    (void)Dir_AddDir(parseIncPath, dir);
}

/*-
 *---------------------------------------------------------------------
 * ParseDoInclude  --
 *	Push to another file.
 *
 *	The input is the line minus the `.'. A file spec is a string
 *	enclosed in <> or "". The former is looked for only in sysIncPath.
 *	The latter in . and the directories specified by -I command line
 *	options
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	A structure is added to the includes Lst and readProc, lineno,
 *	fname and curFILE are altered for the new file
 *---------------------------------------------------------------------
 */
static void
ParseDoInclude(char *line)
{
    char          *fullname;	/* full pathname of file */
    IFile         *oldFile;	/* state associated with current file */
    char          endc;	    	/* the character which ends the file spec */
    char          *cp;		/* current position in file spec */
    Boolean 	  isSystem; 	/* TRUE if makefile is a system makefile */
    int		  silent = (*line != 'i') ? 1 : 0;
    char	  *file = &line[7 + silent];

    /*
     * Skip to delimiter character so we know where to look
     */
    while ((*file == ' ') || (*file == '\t')) {
	file++;
    }

    if ((*file != '"') && (*file != '<')) {
	Parse_Error(PARSE_FATAL,
	    ".include filename must be delimited by '\"' or '<'");
	return;
    }

    /*
     * Set the search path on which to find the include file based on the
     * characters which bracket its name. Angle-brackets imply it's
     * a system Makefile while double-quotes imply it's a user makefile
     */
    if (*file == '<') {
	isSystem = TRUE;
	endc = '>';
    } else {
	isSystem = FALSE;
	endc = '"';
    }

    /*
     * Skip to matching delimiter
     */
    for (cp = ++file; *cp && *cp != endc; cp++) {
	continue;
    }

    if (*cp != endc) {
	Parse_Error(PARSE_FATAL,
		     "Unclosed %cinclude filename. '%c' expected",
		     '.', endc);
	return;
    }
    *cp = '\0';

    /*
     * Substitute for any variables in the file name before trying to
     * find the thing.
     */
    file = Var_Subst(NULL, file, VAR_CMD, FALSE);

    /*
     * Now we know the file's name and its search path, we attempt to
     * find the durn thing. A return of NULL indicates the file don't
     * exist.
     */
    fullname = NULL;

    if (!isSystem) {
	/*
	 * Include files contained in double-quotes are first searched for
	 * relative to the including file's location. We don't want to
	 * cd there, of course, so we just tack on the old file's
	 * leading path components and call Dir_FindFile to see if
	 * we can locate the beast.
	 */
	char	  *prefEnd, *Fname;

	/* Make a temporary copy of this, to be safe. */
	Fname = estrdup(curFile.fname);

	prefEnd = strrchr(Fname, '/');
	if (prefEnd != NULL) {
	    char  	*newName;

	    *prefEnd = '\0';
	    if (file[0] == '/')
		newName = estrdup(file);
	    else
		newName = str_concat(Fname, file, STR_ADDSLASH);
	    fullname = Dir_FindFile(newName, parseIncPath);
	    if (fullname == NULL) {
		fullname = Dir_FindFile(newName, dirSearchPath);
	    }
	    free(newName);
	    *prefEnd = '/';
	} else {
	    fullname = NULL;
	}
	free(Fname);
        if (fullname == NULL) {
	    /*
    	     * Makefile wasn't found in same directory as included makefile.
	     * Search for it first on the -I search path,
	     * then on the .PATH search path, if not found in a -I directory.
	     * XXX: Suffix specific?
	     */
	    fullname = Dir_FindFile(file, parseIncPath);
	    if (fullname == NULL) {
	        fullname = Dir_FindFile(file, dirSearchPath);
	    }
        }
    }

    /* Looking for a system file or file still not found */
    if (fullname == NULL) {
	/*
	 * Look for it on the system path
	 */
	fullname = Dir_FindFile(file, Lst_IsEmpty(sysIncPath) ? defIncPath : sysIncPath);
    }

    if (fullname == NULL) {
	*cp = endc;
	if (!silent)
	    Parse_Error(PARSE_FATAL, "Could not find %s", file);
	return;
    }

    free(file);

    /*
     * Once we find the absolute path to the file, we get to save all the
     * state from the current file before we can start reading this
     * include file. The state is stored in an IFile structure which
     * is placed on a list with other IFile structures. The list makes
     * a very nice stack to track how we got here...
     */
    oldFile = emalloc(sizeof(IFile));

    memcpy(oldFile, &curFile, sizeof(IFile));

    (void)Lst_AtFront(includes, (ClientData)oldFile);

    /*
     * Once the previous state has been saved, we can get down to reading
     * the new file. We set up the name of the file to be the absolute
     * name of the include file so error messages refer to the right
     * place. Naturally enough, we start reading at line number 0.
     */
    curFile.fname = fullname;
    curFile.lineno = 0;

    ParseSetParseFile(curFile.fname);

    curFile.F = fopen(fullname, "r");
    curFile.P = NULL;

    if (curFile.F == (FILE * ) NULL) {
	if (!silent)
	    Parse_Error(PARSE_FATAL, "Cannot open %s", fullname);
	/*
	 * Pop to previous file
	 */
	(void)ParseEOF(0);
    }
}


/*-
 *---------------------------------------------------------------------
 * ParseSetParseFile  --
 *	Set the .PARSEDIR and .PARSEFILE variables to the dirname and
 *	basename of the given filename
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	The .PARSEDIR and .PARSEFILE variables are overwritten by the
 *	dirname and basename of the given filename.
 *---------------------------------------------------------------------
 */
static void
ParseSetParseFile(char *filename)
{
    char *slash;

    slash = strrchr(filename, '/');
    if (slash == 0) {
	Var_Set(".PARSEDIR", ".", VAR_GLOBAL, 0);
	Var_Set(".PARSEFILE", filename, VAR_GLOBAL, 0);
    } else {
	*slash = '\0';
	Var_Set(".PARSEDIR", filename, VAR_GLOBAL, 0);
	Var_Set(".PARSEFILE", slash+1, VAR_GLOBAL, 0);
	*slash = '/';
    }
}


/*-
 *---------------------------------------------------------------------
 * Parse_FromString  --
 *	Start Parsing from the given string
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	A structure is added to the includes Lst and readProc, lineno,
 *	fname and curFILE are altered for the new file
 *---------------------------------------------------------------------
 */
void
Parse_FromString(char *str, int lineno)
{
    IFile         *oldFile;	/* state associated with this file */

    if (DEBUG(FOR))
	(void)fprintf(stderr, "%s\n---- at line %d\n", str, lineno);

    oldFile = emalloc(sizeof(IFile));
    memcpy(oldFile, &curFile, sizeof(IFile));

    (void)Lst_AtFront(includes, (ClientData)oldFile);

    curFile.F = NULL;
    curFile.P = emalloc(sizeof(PTR));
    curFile.P->str = curFile.P->ptr = str;
    curFile.lineno = lineno;
    curFile.fname = estrdup(curFile.fname);
}


#ifdef SYSVINCLUDE
/*-
 *---------------------------------------------------------------------
 * ParseTraditionalInclude  --
 *	Push to another file.
 *
 *	The input is the current line. The file name(s) are
 *	following the "include".
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	A structure is added to the includes Lst and readProc, lineno,
 *	fname and curFILE are altered for the new file
 *---------------------------------------------------------------------
 */
static void
ParseTraditionalInclude(char *line)
{
    char          *fullname;	/* full pathname of file */
    IFile         *oldFile;	/* state associated with current file */
    char          *cp;		/* current position in file spec */
    char	  *prefEnd;
    int		   done = 0;
    int		   silent = (line[0] != 'i') ? 1 : 0;
    char	  *file = &line[silent + 7];
    char	  *cfname;
    size_t	   clineno;

    cfname  = curFile.fname;
    clineno = curFile.lineno;

    if (DEBUG(PARSE)) {
	    printf("ParseTraditionalInclude: %s\n", file);
    }

    /*
     * Skip over whitespace
     */
    while (isspace((unsigned char)*file))
	file++;

    /*
     * Substitute for any variables in the file name before trying to
     * find the thing.
     */
    file = Var_Subst(NULL, file, VAR_CMD, FALSE);

    if (*file == '\0') {
	Parse_Error(PARSE_FATAL,
		     "Filename missing from \"include\"");
	return;
    }

    for (; !done; file = cp + 1) {
	/*
	 * Skip to end of line or next whitespace
	 */
	for (cp = file; *cp && !isspace((unsigned char) *cp); cp++)
	    continue;

	if (*cp)
	    *cp = '\0';
	else
	    done = 1;

	/*
	 * Now we know the file's name, we attempt to find the durn thing.
	 * A return of NULL indicates the file don't exist.
	 *
	 * Include files are first searched for relative to the including
	 * file's location. We don't want to cd there, of course, so we
	 * just tack on the old file's leading path components and call
	 * Dir_FindFile to see if we can locate the beast.
	 * XXX - this *does* search in the current directory, right?
	 */

	prefEnd = strrchr(cfname, '/');
	if (prefEnd != NULL) {
	    char  	*newName;

	    *prefEnd = '\0';
	    newName = str_concat(cfname, file, STR_ADDSLASH);
	    fullname = Dir_FindFile(newName, parseIncPath);
	    if (fullname == NULL) {
		fullname = Dir_FindFile(newName, dirSearchPath);
	    }
	    free(newName);
	    *prefEnd = '/';
	} else {
	    fullname = NULL;
	}

	if (fullname == NULL) {
	    /*
	     * System makefile or makefile wasn't found in same directory as
	     * included makefile. Search for it first on the -I search path,
	     * then on the .PATH search path, if not found in a
	     * -I directory. XXX: Suffix specific?
	     */
	    fullname = Dir_FindFile(file, parseIncPath);
	    if (fullname == NULL) {
		fullname = Dir_FindFile(file, dirSearchPath);
	    }
	}

	if (fullname == NULL) {
	    /*
	     * Still haven't found the makefile. Look for it on the system
	     * path as a last resort.
	     */
	    fullname = Dir_FindFile(file,
			Lst_IsEmpty(sysIncPath) ? defIncPath : sysIncPath);
	}

	if (fullname == NULL) {
	    if (!silent)
		ParseErrorInternal(cfname, clineno, PARSE_FATAL,
		    "Could not find %s", file);
	    free(file);
	    continue;
	}

	free(file);

	/*
	 * Once we find the absolute path to the file, we get to save all
	 * the state from the current file before we can start reading this
	 * include file. The state is stored in an IFile structure which
	 * is placed on a list with other IFile structures. The list makes
	 * a very nice stack to track how we got here...
	 */
	oldFile = emalloc(sizeof(IFile));
	memcpy(oldFile, &curFile, sizeof(IFile));

	(void)Lst_AtFront(includes, (ClientData)oldFile);

	/*
	 * Once the previous state has been saved, we can get down to
	 * reading the new file. We set up the name of the file to be the
	 * absolute name of the include file so error messages refer to the
	 * right place. Naturally enough, we start reading at line number 0.
	 */
	curFile.fname = fullname;
	curFile.lineno = 0;

	curFile.F = fopen(fullname, "r");
	curFile.P = NULL;

	if (curFile.F == NULL) {
	    if (!silent)
		ParseErrorInternal(cfname, clineno, PARSE_FATAL,
		    "Cannot open %s", fullname);
	    /*
	     * Pop to previous file
	     */
	    (void)ParseEOF(1);
	}
    }
}
#endif

/*-
 *---------------------------------------------------------------------
 * ParseEOF  --
 *	Called when EOF is reached in the current file. If we were reading
 *	an include file, the includes stack is popped and things set up
 *	to go back to reading the previous file at the previous location.
 *
 * Results:
 *	CONTINUE if there's more to do. DONE if not.
 *
 * Side Effects:
 *	The old curFILE, is closed. The includes list is shortened.
 *	lineno, curFILE, and fname are changed if CONTINUE is returned.
 *---------------------------------------------------------------------
 */
static int
ParseEOF(int opened)
{
    IFile     *ifile;	/* the state on the top of the includes stack */

    if (Lst_IsEmpty(includes)) {
	Var_Delete(".PARSEDIR", VAR_GLOBAL);
	Var_Delete(".PARSEFILE", VAR_GLOBAL);
	return (DONE);
    }

    ifile = (IFile *)Lst_DeQueue(includes);

    /* XXX dispose of curFile info */
    free( curFile.fname);
    if (opened && curFile.F)
	(void)fclose(curFile.F);
    if (curFile.P) {
	free(curFile.P->str);
	free(curFile.P);
    }

    memcpy(&curFile, ifile, sizeof(IFile));

    free(ifile);

    /* pop the PARSEDIR/PARSEFILE variables */
    ParseSetParseFile(curFile.fname);
    return (CONTINUE);
}

/*-
 *---------------------------------------------------------------------
 * ParseReadc  --
 *	Read a character from the current file
 *
 * Results:
 *	The character that was read
 *
 * Side Effects:
 *---------------------------------------------------------------------
 */
static inline int
ParseReadc(void)
{
    if (curFile.F)
	return fgetc(curFile.F);

    if (curFile.P && *curFile.P->ptr)
	return *curFile.P->ptr++;
    return EOF;
}


/*-
 *---------------------------------------------------------------------
 * ParseUnreadc  --
 *	Put back a character to the current file
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *---------------------------------------------------------------------
 */
static void
ParseUnreadc(int c)
{
    if (curFile.F) {
	ungetc(c, curFile.F);
	return;
    }
    if (curFile.P) {
	*--(curFile.P->ptr) = c;
	return;
    }
}


/* ParseSkipLine():
 *	Grab the next line
 *
 * Input:
 *	skip		Skip lines that don't start with .
 *	keep_newline	Keep newline character as is.
 *
 */
static char *
ParseSkipLine(int skip, int keep_newline)
{
    char *line;
    int c, lastc, lineLength = 0;
    Buffer buf;

    buf = Buf_Init(MAKE_BSIZE);

    do {
        Buf_Discard(buf, lineLength);
        lastc = '\0';

        while (((c = ParseReadc()) != '\n' || lastc == '\\')
               && c != EOF) {
            if (c == '\n') {
                if (keep_newline)
                    Buf_AddByte(buf, (Byte)c);
                else
                    Buf_ReplaceLastByte(buf, (Byte)' ');
                curFile.lineno++;

                while ((c = ParseReadc()) == ' ' || c == '\t');

                if (c == EOF)
                    break;
            }

            Buf_AddByte(buf, (Byte)c);
            lastc = c;
        }

        if (c == EOF) {
            Parse_Error(PARSE_FATAL, "Unclosed conditional/for loop");
            Buf_Destroy(buf, TRUE);
            return(NULL);
        }

        curFile.lineno++;
        Buf_AddByte(buf, (Byte)'\0');
        line = (char *)Buf_GetAll(buf, &lineLength);
    } while (skip == 1 && line[0] != '.');

    Buf_Destroy(buf, FALSE);
    return line;
}


/*-
 *---------------------------------------------------------------------
 * ParseReadLine --
 *	Read an entire line from the input file. Called only by Parse_File.
 *	To facilitate escaped newlines and what have you, a character is
 *	buffered in 'lastc', which is '\0' when no characters have been
 *	read. When we break out of the loop, c holds the terminating
 *	character and lastc holds a character that should be added to
 *	the line (unless we don't read anything but a terminator).
 *
 * Results:
 *	A line w/o its newline
 *
 * Side Effects:
 *	Only those associated with reading a character
 *---------------------------------------------------------------------
 */
static char *
ParseReadLine(void)
{
    Buffer  	  buf;	    	/* Buffer for current line */
    int		  c;	      	/* the current character */
    int		  lastc;    	/* The most-recent character */
    Boolean	  semiNL;     	/* treat semi-colons as newlines */
    Boolean	  ignDepOp;   	/* TRUE if should ignore dependency operators
				 * for the purposes of setting semiNL */
    Boolean 	  ignComment;	/* TRUE if should ignore comments (in a
				 * shell command */
    char 	  *line;    	/* Result */
    char          *ep;		/* to strip trailing blanks */
    int	    	  lineLength;	/* Length of result */
    int	    	  lineno;	/* Saved line # */

    semiNL = FALSE;
    ignDepOp = FALSE;
    ignComment = FALSE;

    /*
     * Handle special-characters at the beginning of the line. Either a
     * leading tab (shell command) or pound-sign (possible conditional)
     * forces us to ignore comments and dependency operators and treat
     * semi-colons as semi-colons (by leaving semiNL FALSE). This also
     * discards completely blank lines.
     */
    for (;;) {
	c = ParseReadc();

	if (c == '\t') {
	    ignComment = ignDepOp = TRUE;
	    break;
	} else if (c == '\n') {
	    curFile.lineno++;
	} else if (c == '#') {
	    ParseUnreadc(c);
	    break;
	} else {
	    /*
	     * Anything else breaks out without doing anything
	     */
	    break;
	}
    }

    if (c != EOF) {
	lastc = c;
	buf = Buf_Init(MAKE_BSIZE);

	while (((c = ParseReadc()) != '\n' || (lastc == '\\')) &&
	       (c != EOF))
	{
test_char:
	    switch(c) {
	    case '\n':
		/*
		 * Escaped newline: read characters until a non-space or an
		 * unescaped newline and replace them all by a single space.
		 * This is done by storing the space over the backslash and
		 * dropping through with the next nonspace. If it is a
		 * semi-colon and semiNL is TRUE, it will be recognized as a
		 * newline in the code below this...
		 */
		curFile.lineno++;
		lastc = ' ';
		while ((c = ParseReadc()) == ' ' || c == '\t') {
		    continue;
		}
		if (c == EOF || c == '\n') {
		    goto line_read;
		} else {
		    /*
		     * Check for comments, semiNL's, etc. -- easier than
		     * ParseUnreadc(c); continue;
		     */
		    goto test_char;
		}
		/*NOTREACHED*/
		break;

	    case ';':
		/*
		 * Semi-colon: Need to see if it should be interpreted as a
		 * newline
		 */
		if (semiNL) {
		    /*
		     * To make sure the command that may be following this
		     * semi-colon begins with a tab, we push one back into the
		     * input stream. This will overwrite the semi-colon in the
		     * buffer. If there is no command following, this does no
		     * harm, since the newline remains in the buffer and the
		     * whole line is ignored.
		     */
		    ParseUnreadc('\t');
		    goto line_read;
		}
		break;
	    case '=':
		if (!semiNL) {
		    /*
		     * Haven't seen a dependency operator before this, so this
		     * must be a variable assignment -- don't pay attention to
		     * dependency operators after this.
		     */
		    ignDepOp = TRUE;
		} else if (lastc == ':' || lastc == '!') {
		    /*
		     * Well, we've seen a dependency operator already, but it
		     * was the previous character, so this is really just an
		     * expanded variable assignment. Revert semi-colons to
		     * being just semi-colons again and ignore any more
		     * dependency operators.
		     *
		     * XXX: Note that a line like "foo : a:=b" will blow up,
		     * but who'd write a line like that anyway?
		     */
		    ignDepOp = TRUE; semiNL = FALSE;
		}
		break;
	    case '#':
		if (!ignComment) {
		    if (
#if 0
		    compatMake &&
#endif
		    (lastc != '\\')) {
			/*
			 * If the character is a hash mark and it isn't escaped
			 * (or we're being compatible), the thing is a comment.
			 * Skip to the end of the line.
			 */
			do {
			    c = ParseReadc();
			    /*
			     * If we found a backslash not escaped
			     * itself it means that the comment is
			     * going to continue in the next line.
			     */
			    if (c == '\\')
				ParseReadc();
			} while ((c != '\n') && (c != EOF));
			goto line_read;
		    } else {
			/*
			 * Don't add the backslash. Just let the # get copied
			 * over.
			 */
			lastc = c;
			continue;
		    }
		}
		break;
	    case ':':
	    case '!':
		if (!ignDepOp && (c == ':' || c == '!')) {
		    /*
		     * A semi-colon is recognized as a newline only on
		     * dependency lines. Dependency lines are lines with a
		     * colon or an exclamation point. Ergo...
		     */
		    semiNL = TRUE;
		}
		break;
	    }
	    /*
	     * Copy in the previous character and save this one in lastc.
	     */
	    Buf_AddByte(buf, (Byte)lastc);
	    lastc = c;

	}
    line_read:
	curFile.lineno++;

	if (lastc != '\0') {
	    Buf_AddByte(buf, (Byte)lastc);
	}
	Buf_AddByte(buf, (Byte)'\0');
	line = (char *)Buf_GetAll(buf, &lineLength);
	Buf_Destroy(buf, FALSE);

	/*
	 * Strip trailing blanks and tabs from the line.
	 * Do not strip a blank or tab that is preceded by
	 * a '\'
	 */
	ep = line;
	while (*ep)
	    ++ep;
	while (ep > line + 1 && (ep[-1] == ' ' || ep[-1] == '\t')) {
	    if (ep > line + 1 && ep[-2] == '\\')
		break;
	    --ep;
	}
	*ep = 0;

	if (line[0] == '.') {
	    /*
	     * The line might be a conditional. Ask the conditional module
	     * about it and act accordingly
	     */
	    switch (Cond_Eval(line)) {
	    case COND_SKIP:
		/*
		 * Skip to next conditional that evaluates to COND_PARSE.
		 */
		do {
		    free(line);
		    line = ParseSkipLine(1, 0);
		} while (line && Cond_Eval(line) != COND_PARSE);
		if (line == NULL)
		    break;
		/*FALLTHRU*/
	    case COND_PARSE:
		free(line);
		line = ParseReadLine();
		break;
	    case COND_INVALID:
		lineno = curFile.lineno;
		if (For_Eval(line)) {
		    int ok;
		    free(line);
		    do {
			/*
			 * Skip after the matching end
			 */
			line = ParseSkipLine(0, 1);
			if (line == NULL) {
			    Parse_Error(PARSE_FATAL,
				     "Unexpected end of file in for loop.\n");
			    break;
			}
			ok = For_Eval(line);
			free(line);
		    }
		    while (ok);
		    if (line != NULL)
			For_Run(lineno);
		    line = ParseReadLine();
		}
		break;
	    }
	}
	return (line);

    } else {
	/*
	 * Hit end-of-file, so return a NULL line to indicate this.
	 */
	return(NULL);
    }
}

/*-
 *-----------------------------------------------------------------------
 * ParseFinishLine --
 *	Handle the end of a dependency group.
 *
 * Results:
 *	Nothing.
 *
 * Side Effects:
 *	inLine set FALSE. 'targets' list destroyed.
 *
 *-----------------------------------------------------------------------
 */
static void
ParseFinishLine(void)
{
    if (inLine) {
	Lst_ForEach(targets, Suff_EndTransform, (ClientData)NULL);
	Lst_Destroy(targets, ParseHasCommands);
	targets = NULL;
	inLine = FALSE;
    }
}


/*-
 *---------------------------------------------------------------------
 * Parse_File --
 *	Parse a file into its component parts, incorporating it into the
 *	current dependency graph. This is the main function and controls
 *	almost every other function in this module
 *
 * Input:
 *	name		the name of the file being read
 *	stream		Stream open to makefile to parse
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	Loads. Nodes are added to the list of all targets, nodes and links
 *	are added to the dependency graph. etc. etc. etc.
 *---------------------------------------------------------------------
 */
void
Parse_File(const char *name, FILE *stream)
{
    char	  *cp,		/* pointer into the line */
                  *line;	/* the line we're working on */

    inLine = FALSE;
    fatals = 0;

    curFile.fname = UNCONST(name);
    curFile.F = stream;
    curFile.lineno = 0;

    ParseSetParseFile(curFile.fname);

    do {
	while ((line = ParseReadLine()) != NULL) {
	    if (*line == '.') {
		/*
		 * Lines that begin with the special character are either
		 * include or undef directives.
		 */
		for (cp = line + 1; isspace ((unsigned char)*cp); cp++) {
		    continue;
		}
		if (strncmp(cp, "include", 7) == 0 ||
	    	    ((cp[0] == 's' || cp[0] == '-') &&
		    strncmp(&cp[1], "include", 7) == 0)) {
		    ParseDoInclude(cp);
		    goto nextLine;
		} else if (strncmp(cp, "undef", 5) == 0) {
		    char *cp2;
		    for (cp += 5; isspace((unsigned char) *cp); cp++) {
			continue;
		    }

		    for (cp2 = cp; !isspace((unsigned char) *cp2) &&
				   (*cp2 != '\0'); cp2++) {
			continue;
		    }

		    *cp2 = '\0';

		    Var_Delete(cp, VAR_GLOBAL);
		    goto nextLine;
		}
	    }
	    if (*line == '#') {
		/* If we're this far, the line must be a comment. */
		goto nextLine;
	    }

	    if (*line == '\t') {
		/*
		 * If a line starts with a tab, it can only hope to be
		 * a creation command.
		 */
#ifndef POSIX
	    shellCommand:
#endif
		for (cp = line + 1; isspace ((unsigned char)*cp); cp++) {
		    continue;
		}
		if (*cp) {
		    if (inLine) {
			/*
			 * So long as it's not a blank line and we're actually
			 * in a dependency spec, add the command to the list of
			 * commands of all targets in the dependency spec
			 */
			Lst_ForEach(targets, ParseAddCmd, cp);
#ifdef CLEANUP
			Lst_AtEnd(targCmds, (ClientData) line);
#endif
			continue;
		    } else {
			Parse_Error(PARSE_FATAL,
				     "Unassociated shell command \"%s\"",
				     cp);
		    }
		}
#ifdef SYSVINCLUDE
	    } else if (((strncmp(line, "include", 7) == 0 &&
	        isspace((unsigned char) line[7])) ||
	        ((line[0] == 's' || line[0] == '-') &&
	        strncmp(&line[1], "include", 7) == 0 &&
	        isspace((unsigned char) line[8]))) &&
	        strchr(line, ':') == NULL) {
		/*
		 * It's an S3/S5-style "include".
		 */
		ParseTraditionalInclude(line);
		goto nextLine;
#endif
	    } else if (Parse_IsVar(line)) {
		ParseFinishLine();
		Parse_DoVar(line, VAR_GLOBAL);
	    } else {
		/*
		 * We now know it's a dependency line so it needs to have all
		 * variables expanded before being parsed. Tell the variable
		 * module to complain if some variable is undefined...
		 * To make life easier on novices, if the line is indented we
		 * first make sure the line has a dependency operator in it.
		 * If it doesn't have an operator and we're in a dependency
		 * line's script, we assume it's actually a shell command
		 * and add it to the current list of targets.
		 */
#ifndef POSIX
		Boolean	nonSpace = FALSE;
#endif

		cp = line;
		if (isspace((unsigned char) line[0])) {
		    while ((*cp != '\0') && isspace((unsigned char) *cp)) {
			cp++;
		    }
		    if (*cp == '\0') {
			goto nextLine;
		    }
#ifndef POSIX
		    while (*cp && (ParseIsEscaped(line, cp) ||
			(*cp != ':') && (*cp != '!'))) {
			nonSpace = TRUE;
			cp++;
		    }
#endif
		}

#ifndef POSIX
		if (*cp == '\0') {
		    if (inLine) {
			Parse_Error(PARSE_WARNING,
				     "Shell command needs a leading tab");
			goto shellCommand;
		    } else if (nonSpace) {
			Parse_Error(PARSE_FATAL, "Missing operator");
		    }
		} else {
#endif
		    ParseFinishLine();

		    cp = Var_Subst(NULL, line, VAR_CMD, TRUE);
		    free(line);
		    line = cp;

		    /*
		     * Need a non-circular list for the target nodes
		     */
		    if (targets)
			Lst_Destroy(targets, NOFREE);

		    targets = Lst_Init(FALSE);
		    inLine = TRUE;

		    ParseDoDependency(line);
#ifndef POSIX
		}
#endif
	    }

	    nextLine:

	    free(line);
	}
	/*
	 * Reached EOF, but it may be just EOF of an include file...
	 */
    } while (ParseEOF(1) == CONTINUE);

    /*
     * Make sure conditionals are clean
     */
    Cond_End();

    if (fatals) {
	(void)fprintf(stderr,
	    "%s: Fatal errors encountered -- cannot continue\n",
	    progname);
	PrintOnError(NULL);
	exit(1);
    }
}

/*-
 *---------------------------------------------------------------------
 * Parse_Init --
 *	initialize the parsing module
 *
 * Results:
 *	none
 *
 * Side Effects:
 *	the parseIncPath list is initialized...
 *---------------------------------------------------------------------
 */
void
Parse_Init(void)
{
    mainNode = NILGNODE;
    parseIncPath = Lst_Init(FALSE);
    sysIncPath = Lst_Init(FALSE);
    defIncPath = Lst_Init(FALSE);
    includes = Lst_Init(FALSE);
#ifdef CLEANUP
    targCmds = Lst_Init(FALSE);
#endif
}

void
Parse_End(void)
{
#ifdef CLEANUP
    Lst_Destroy(targCmds, (FreeProc *)free);
    if (targets)
	Lst_Destroy(targets, NOFREE);
    Lst_Destroy(defIncPath, Dir_Destroy);
    Lst_Destroy(sysIncPath, Dir_Destroy);
    Lst_Destroy(parseIncPath, Dir_Destroy);
    Lst_Destroy(includes, NOFREE);	/* Should be empty now */
#endif
}


/*-
 *-----------------------------------------------------------------------
 * Parse_MainName --
 *	Return a Lst of the main target to create for main()'s sake. If
 *	no such target exists, we Punt with an obnoxious error message.
 *
 * Results:
 *	A Lst of the single node to create.
 *
 * Side Effects:
 *	None.
 *
 *-----------------------------------------------------------------------
 */
Lst
Parse_MainName(void)
{
    Lst           mainList;	/* result list */

    mainList = Lst_Init(FALSE);

    if (mainNode == NILGNODE) {
	Punt("no target to make.");
    	/*NOTREACHED*/
    } else if (mainNode->type & OP_DOUBLEDEP) {
	(void)Lst_AtEnd(mainList, (ClientData)mainNode);
	Lst_Concat(mainList, mainNode->cohorts, LST_CONCNEW);
    }
    else
	(void)Lst_AtEnd(mainList, (ClientData)mainNode);
    Var_Append(".TARGETS", mainNode->name, VAR_GLOBAL);
    return (mainList);
}

/*-
 *-----------------------------------------------------------------------
 * ParseMark --
 *	Add the filename and lineno to the GNode so that we remember
 *	where it was first defined.
 *
 * Side Effects:
 *	None.
 *
 *-----------------------------------------------------------------------
 */
static void
ParseMark(GNode *gn)
{
    gn->fname = strdup(curFile.fname);
    gn->lineno = curFile.lineno;
}