xref: /freebsd-10.0-release/usr.bin/make/parse.c

/*-
 * Copyright (c) 1988, 1989, 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 * 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.
 *
 * @(#)parse.c	8.3 (Berkeley) 3/19/94
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: head/usr.bin/make/parse.c 144020 2005-03-23 12:56:15Z harti $");

/*-
 * 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 'curFile.fname' and 'curFile.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_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 <stdarg.h>
#include <string.h>
#include <stdlib.h>
#include <err.h>

#include "arch.h"
#include "buf.h"
#include "cond.h"
#include "config.h"
#include "dir.h"
#include "for.h"
#include "globals.h"
#include "GNode.h"
#include "job.h"
#include "make.h"
#include "nonints.h"
#include "parse.h"
#include "pathnames.h"
#include "str.h"
#include "suff.h"
#include "targ.h"
#include "util.h"
#include "var.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

/* targets we're working on */
static Lst targets = Lst_Initializer(targets);

static Boolean	    inLine;	/* true if currently in a dependency
				 * line or its commands */
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 */

IFile	    	curFile;	/* current makefile */

/* stack of IFiles generated by * #includes */
static Lst includes = Lst_Initializer(includes);

/* list of directories for "..." includes */
struct Path parseIncPath = TAILQ_HEAD_INITIALIZER(parseIncPath);

/* list of directories for <...> includes */
struct Path sysIncPath = TAILQ_HEAD_INITIALIZER(sysIncPath);

/*-
 * 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 */
    Not,	    /* Not special */
    NotParallel,    /* .NOTPARALELL */
    Null,   	    /* .NULL */
    Order,  	    /* .ORDER */
    Parallel,	    /* .PARALLEL */
    ExPath,	    /* .PATH */
    Phony,	    /* .PHONY */
    Posix,	    /* .POSIX */
    Precious,	    /* .PRECIOUS */
    ExShell,	    /* .SHELL */
    Silent,	    /* .SILENT */
    SingleShell,    /* .SINGLESHELL */
    Suffixes,	    /* .SUFFIXES */
    Wait,	    /* .WAIT */
    Attribute	    /* Generic attribute */
} ParseSpecial;

static ParseSpecial specType;
static int waiting;

/*
 * Predecessor node for handling .ORDER. Initialized to NULL 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 },
{ ".MAIN",	  Main,		0 },
{ ".MAKE",  	  Attribute,   	OP_MAKE },
{ ".MAKEFLAGS",	  MFlags,   	0 },
{ ".MFLAGS",	  MFlags,   	0 },
{ ".NOTMAIN",	  Attribute,   	OP_NOTMAIN },
{ ".NOTPARALLEL", NotParallel,	0 },
{ ".NO_PARALLEL", NotParallel,	0 },
{ ".NULL",  	  Null,	    	0 },
{ ".OPTIONAL",	  Attribute,   	OP_OPTIONAL },
{ ".ORDER", 	  Order,    	0 },
{ ".PARALLEL",	  Parallel,	0 },
{ ".PATH",	  ExPath,	0 },
{ ".PHONY",	  Phony,	OP_PHONY },
{ ".POSIX",	  Posix,	0 },
{ ".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 },
{ ".WAIT",	  Wait, 	0 },
};

static int ParseFindKeyword(char *);
static void ParseDoSrc(int, char *, Lst *);
static void ParseDoDependency(char *);
static int ParseReadc(void);
static void ParseUnreadc(int);
static void ParseHasCommands(void *);
static void ParseDoInclude(char *);
static void ParseDoError(char *);
static void ParseDoWarning(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);

/*-
 *----------------------------------------------------------------------
 * ParseFindKeyword --
 *	Look in the table of keywords for one matching the given string.
 *
 * 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);
}

/*-
 * Parse_Error  --
 *	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 */
void
Parse_Error(int type, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	fprintf(stderr, "\"%s\", line %d: ",
	    curFile.fname, curFile.lineno);
	if (type == PARSE_WARNING)
		fprintf(stderr, "warning: ");
	vfprintf(stderr, fmt, ap);
	va_end(ap);
	fprintf(stderr, "\n");
	fflush(stderr);
	if (type == PARSE_FATAL)
		fatals += 1;
}

/*-
 *---------------------------------------------------------------------
 * ParseLinkSrc  --
 *	Link the parent nodes to their new child. Used by
 *	ParseDoDependency. If the specType isn't 'Not', the parent
 *	isn't linked as a parent of the child.
 *
 * Side Effects:
 *	New elements are added to the parents lists of cgn and the
 *	children list of cgn. the unmade field of pgn is updated
 *	to reflect the additional child.
 *---------------------------------------------------------------------
 */
static void
ParseLinkSrc(Lst *parents, GNode *cgn)
{
	LstNode	*ln;
	GNode *pgn;

	LST_FOREACH(ln, parents) {
		pgn = Lst_Datum(ln);
		if (Lst_Member(&pgn->children, cgn) == NULL) {
			Lst_AtEnd(&pgn->children, cgn);
			if (specType == Not) {
				Lst_AtEnd(&cgn->parents, pgn);
			}
			pgn->unmade += 1;
		}
	}
}

/*-
 *---------------------------------------------------------------------
 * ParseDoOp  --
 *	Apply the parsed operator to all target nodes. Used in
 *	ParseDoDependency once all targets have been found and their
 *	operator parsed. If the previous and new operators are incompatible,
 *	a major error is taken.
 *
 * Side Effects:
 *	The type field of the node is altered to reflect any new bits in
 *	the op.
 *---------------------------------------------------------------------
 */
static void
ParseDoOp(int op)
{
	GNode	*cohort;
	LstNode	*ln;
	GNode	*gn;

	LST_FOREACH(ln, &targets) {
		gn = Lst_Datum(ln);

		/*
		 * 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;
		}

		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.
			 */
			cohort = Targ_NewGN(gn->name);

			/*
			 * Duplicate links to parents so graph traversal is
			 * simple. Perhaps some type bits should be duplicated?
			 *
			 * 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.
			 */
			ParseLinkSrc(&gn->parents, cohort);
			cohort->type = OP_DOUBLEDEP|OP_INVISIBLE;
			Lst_AtEnd(&gn->cohorts, cohort);

			/*
			 * Replace the node in the targets list with the
			 * new copy
			 */
			Lst_Replace(ln, cohort);
			gn = cohort;
		}
		/*
		 * 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;
	}
}

/*-
 *---------------------------------------------------------------------
 * 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'
 *
 * 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)
{
    GNode	*gn = NULL;

    if (*src == '.' && isupper ((unsigned char) src[1])) {
	int keywd = ParseFindKeyword(src);
	if (keywd != -1) {
	    if(parseKeywords[keywd].op != 0) {
		ParseDoOp(parseKeywords[keywd].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...
	 */
	Lst_AtEnd(&create, 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 != NULL) {
	    Lst_AtEnd(&predecessor->successors, gn);
	    Lst_AtEnd(&gn->preds, predecessor);
	}
	/*
	 * 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.
	 */
	gn = Targ_FindNode(src, TARG_CREATE);
	if (tOp) {
	    gn->type |= tOp;
	} else {
	    ParseLinkSrc(&targets, gn);
	}
	if ((gn->type & OP_OPMASK) == OP_DOUBLEDEP) {
	    GNode  	*cohort;
	    LstNode	*ln;

	    for (ln = Lst_First(&gn->cohorts); ln != NULL; ln = Lst_Succ(ln)) {
		cohort = Lst_Datum(ln);
		if (tOp) {
		    cohort->type |= tOp;
		} else {
		    ParseLinkSrc(&targets, cohort);
		}
	    }
	}
	break;
    }

    gn->order = waiting;
    Lst_AtEnd(allsrc, gn);
    if (waiting) {
	LstNode	*ln;
	GNode	*p;

	/*
	 * Check if GNodes needs to be synchronized.
	 * This has to be when two nodes are on different sides of a
	 * .WAIT directive.
	 */
	LST_FOREACH(ln, allsrc) {
		p = Lst_Datum(ln);

		if (p->order >= gn->order)
			break;
		/*
		 * XXX: This can cause loops, and loops can cause
		 * unmade targets, but checking is tedious, and the
		 * debugging output can show the problem
		 */
		Lst_AtEnd(&p->successors, gn);
		Lst_AtEnd(&gn->preds, p);
	}
    }
}


/*-
 *---------------------------------------------------------------------
 * ParseDoDependency  --
 *	Parse the dependency line in line.
 *
 * 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;		/* a general purpose temporary node */
    int             op;		/* the operator on the line */
    char            savec;	/* a place to save a character */
    Lst paths;	/* Search paths to alter when parsing a list of .PATH targets */
    int	    	    tOp;    	/* operator from special target */
    LstNode	    *ln;

    tOp = 0;

    specType = Not;
    waiting = 0;
    Lst_Init(&paths);

    do {
	for (cp = line;
	    *cp && !isspace((unsigned char)*cp) && *cp != '(';
	    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.
		 */
		size_t	length = 0;
		Boolean	freeIt;
		char	*result;

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

		if (freeIt) {
		    free(result);
		}
		cp += length - 1;
	    } else if (*cp == '!' || *cp == ':') {
		/*
		 * We don't want to end a word on ':' or '!' if there is a
		 * better match later on in the string (greedy matching).
		 * This allows the user to have targets like:
		 *    fie::fi:fo: fum
		 *    foo::bar:
		 * where "fie::fi:fo" and "foo::bar" are the targets.  In
		 * real life this is used for perl5 library man pages where
		 * "::" separates an object from its class.
		 * Ie: "File::Spec::Unix".  This behaviour is also consistent
		 * with other versions of make.
		 */
		char *p = cp + 1;

		if (*cp == ':' && *p == ':')
		    p++;

		/* Found the best match already. */
		if (*p == '\0' || isspace(*p))
		    break;

		p += strcspn(p, "!:");

		/* No better match later on... */
		if (*p == '\0')
		    break;
	    }
	    continue;
	}
	if (*cp == '(') {
	    /*
	     * 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);
		return;
	    } else {
		cp = line;
		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");
	    return;
	}
	*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");
		    return;
		}

		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
		 *	.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 NULL
		 */
		switch (specType) {
		    case ExPath:
			Lst_AtEnd(&paths, &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;
			Lst_AtEnd(&targets, gn);
			break;
		    case Default:
			gn = Targ_NewGN(".DEFAULT");
			gn->type |= (OP_NOTMAIN|OP_TRANSFORM);
			Lst_AtEnd(&targets, gn);
			DEFAULT = gn;
			break;
		    case NotParallel:
		    {
			maxJobs = 1;
			break;
		    }
		    case SingleShell:
			compatMake = 1;
			break;
		    case Order:
			predecessor = NULL;
			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.
		 */
		struct Path *path;

		specType = ExPath;
		path = Suff_GetPath(&line[5]);
		if (path == NULL) {
		    Parse_Error(PARSE_FATAL,
				 "Suffix '%s' not defined (yet)",
				 &line[5]);
		    return;
		} else
		    Lst_AtEnd(&paths, 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')) {
	    /* target names to be found and added to targets list */
	    Lst curTargs = Lst_Initializer(curTargs);

	    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...
		 */
		struct Path emptyPath = TAILQ_HEAD_INITIALIZER(emptyPath);

		Path_Expand(line, &emptyPath, &curTargs);
		Path_Clear(&emptyPath);

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

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

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

		Lst_AtEnd(&targets, 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 warnFlag = FALSE;

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

    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");
	return;
    }

    cp++;			/* Advance beyond operator */

    ParseDoOp(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(ln, &paths)
		    Path_Clear(Lst_Datum(ln));
		break;
	    case Posix:
		Var_Set("%POSIX", "1003.2", VAR_GLOBAL);
		break;
	    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, 0);
	*line = '\0';
    } else if (specType == ExShell) {
	if (Job_ParseShell(line) != SUCCESS) {
	    Parse_Error(PARSE_FATAL, "improper shell specification");
	    return;
	}
	*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))
    {
	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.
	     */
	    char  savech;
	    while (*cp && !isspace((unsigned char)*cp)) {
		cp++;
	    }
	    savech = *cp;
	    *cp = '\0';
	    switch (specType) {
		case Suffixes:
		    Suff_AddSuffix(line);
		    break;
		case ExPath:
		    LST_FOREACH(ln, &paths)
			Path_AddDir(Lst_Datum(ln), line);
		    break;
		case Includes:
		    Suff_AddInclude(line);
		    break;
		case Libs:
		    Suff_AddLib(line);
		    break;
		case Null:
		    Suff_SetNull(line);
		    break;
		default:
		    break;
	    }
	    *cp = savech;
	    if (savech != '\0') {
		cp++;
	    }
	    while (*cp && isspace((unsigned char)*cp)) {
		cp++;
	    }
	    line = cp;
	}
	Lst_Destroy(&paths, NOFREE);

    } else {
        Lst curSrcs = Lst_Initializer(curSrc);	/* list of sources in order */

	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 == '(') && (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 == '(') {
		GNode	  *gnp;
		/* list of archive source names after expansion */
		Lst sources = Lst_Initializer(sources);

		if (Arch_ParseArchive(&line, &sources, VAR_CMD) != SUCCESS) {
		    Parse_Error(PARSE_FATAL,
				 "Error in source archive spec \"%s\"", line);
		    return;
		}

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

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

    if (mainNode == NULL) {
	/*
	 * 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(ln, &targets) {
	    gn = Lst_Datum(ln);
	    if ((gn->type & (OP_NOTMAIN | OP_USE |
		OP_EXEC | OP_TRANSFORM)) == 0) {
		mainNode = gn;
		Targ_SetMain(gn);
		break;
	    }
	}
    }
}

/*-
 *---------------------------------------------------------------------
 * 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.
 *
 * 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 '(':
	case '{':
	    level++;
	    break;

	case '}':
	case ')':
	    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++ =".
 *
 * 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 */
    /*
     * 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 != ':')
		if (opc == line)
		    break;
		else
		    --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);

	cp = Buf_Peel(Var_Subst(NULL, cp, ctxt, FALSE));

	oldVars = oldOldVars;

	Var_Set(line, cp, ctxt);
	free(cp);
    } else if (type == VAR_SHELL) {
	Boolean	freeCmd = FALSE; /* TRUE if the command needs to be freed, i.e.
				  * if any variable expansion was performed */
	Buffer *buf;
	const char *error;

	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 = Buf_Peel(Var_Subst(NULL, cp, VAR_CMD, TRUE));
	    freeCmd = TRUE;
	}

	buf = Cmd_Exec(cp, &error);
	Var_Set(line, Buf_Data(buf), ctxt);
	Buf_Destroy(buf, TRUE);

	if (error)
	    Parse_Error(PARSE_WARNING, error, cp);

	if (freeCmd)
	    free(cp);
    } else {
	/*
	 * Normal assignment -- just do it.
	 */
	Var_Set(line, cp, ctxt);
    }
}

/*-
 *-----------------------------------------------------------------------
 * 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.
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	OP_HAS_COMMANDS may be set for the target.
 *
 *-----------------------------------------------------------------------
 */
static void
ParseHasCommands(void *gnp)
{
    GNode *gn = 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
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	The directory is appended to the list.
 *
 *-----------------------------------------------------------------------
 */
void
Parse_AddIncludeDir(char *dir)
{

    Path_AddDir(&parseIncPath, dir);
}

/*---------------------------------------------------------------------
 * ParseDoError  --
 *	Handle error directive
 *
 *	The input is the line minus the ".error".  We substitute variables,
 *	print the message and exit(1) or just print a warning if the ".error"
 *	directive is malformed.
 *
 *---------------------------------------------------------------------
 */
static void
ParseDoError(char *errmsg)
{
	Buffer *buf;

	if (!isspace((unsigned char)*errmsg)) {
		Parse_Error(PARSE_WARNING, "invalid syntax: .error%s", errmsg);
		return;
	}

	while (isspace((unsigned char)*errmsg))
		errmsg++;

	buf = Var_Subst(NULL, errmsg, VAR_GLOBAL, FALSE);
	Parse_Error(PARSE_FATAL, "%s", Buf_Data(buf));
	Buf_Destroy(buf, TRUE);

	/* Terminate immediately. */
	exit(1);
}

/*---------------------------------------------------------------------
 * ParseDoWarning  --
 *	Handle warning directive
 *
 *	The input is the line minus the ".warning".  We substitute variables
 *	and print the message or just print a warning if the ".warning"
 *	directive is malformed.
 *
 *---------------------------------------------------------------------
 */
static void
ParseDoWarning(char *warnmsg)
{
	Buffer *buf;

	if (!isspace((unsigned char)*warnmsg)) {
		Parse_Error(PARSE_WARNING, "invalid syntax: .warning%s",
		    warnmsg);
		return;
	}

	while (isspace((unsigned char)*warnmsg))
		warnmsg++;

	buf = Var_Subst(NULL, warnmsg, VAR_GLOBAL, FALSE);
	Parse_Error(PARSE_WARNING, "%s", Buf_Data(buf));
	Buf_Destroy(buf, TRUE);
}

/*-
 *---------------------------------------------------------------------
 * ParseDoInclude  --
 *	Push to another file.
 *
 *	The input is the line minus the #include. 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, curFile.lineno,
 *	curFile.fname and curFile.F are altered for the new file
 *---------------------------------------------------------------------
 */
static void
ParseDoInclude(char *file)
{
    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 */
    Buffer	  *buf;

    /*
     * 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.
     */
    buf = Var_Subst(NULL, file, VAR_CMD, FALSE);
    file = Buf_Peel(buf);

    /*
     * 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.
     */
    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 != (char *)NULL) {
	    char  	*newName;

	    *prefEnd = '\0';
	    if (file[0] == '/')
		newName = estrdup(file);
	    else
		newName = str_concat(Fname, file, STR_ADDSLASH);
	    fullname = Path_FindFile(newName, &parseIncPath);
	    if (fullname == NULL) {
		fullname = Path_FindFile(newName, &dirSearchPath);
	    }
	    free(newName);
	    *prefEnd = '/';
	} else {
	    fullname = NULL;
	}
	free(Fname);
    } 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 = Path_FindFile(file, &parseIncPath);
	if (fullname == NULL) {
	    fullname = Path_FindFile(file, &dirSearchPath);
	}
    }

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

    if (fullname == NULL) {
	*cp = endc;
	Parse_Error(PARSE_FATAL, "Could not find %s", file);
	/* XXXHB free(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));

    Lst_AtFront(&includes, 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) {
	Parse_Error(PARSE_FATAL, "Cannot open %s", fullname);
	/*
	 * Pop to previous file
	 */
	ParseEOF(0);
    } else {
	Var_Append(".MAKEFILE_LIST", fullname, VAR_GLOBAL);
    }
}

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

    DEBUGF(FOR, ("%s\n---- at line %d\n", str, lineno));

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

    Lst_AtFront(&includes, 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 line minus the "include".  The file name is
 *	the string following the "include".
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	A structure is added to the includes Lst and readProc, curFile.lineno,
 *	curFile.fname and curFile.F are altered for the new file
 *---------------------------------------------------------------------
 */
static void
ParseTraditionalInclude(char *file)
{
    char          *fullname;	/* full pathname of file */
    IFile         *oldFile;	/* state associated with current file */
    char          *cp;		/* current position in file spec */
    Buffer	  *buf;

    /*
     * Skip over whitespace
     */
    while ((*file == ' ') || (*file == '\t')) {
	file++;
    }

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

    /*
     * Skip to end of line or next whitespace
     */
    for (cp = file; *cp && *cp != '\n' && *cp != '\t' && *cp != ' '; cp++) {
	continue;
    }

    *cp = '\0';

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

    /*
     * Now we know the file's name, we attempt to find the durn thing.
     * Search for it first on the -I search path, then on the .PATH
     * search path, if not found in a -I directory.
     */
    fullname = Path_FindFile(file, &parseIncPath);
    if (fullname == NULL) {
        fullname = Path_FindFile(file, &dirSearchPath);
    }

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

    if (fullname == NULL) {
	Parse_Error(PARSE_FATAL, "Could not find %s", file);
	/* XXXHB free(file) */
	return;
    }

    /* XXXHB 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));

    Lst_AtFront(&includes, 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) {
	Parse_Error(PARSE_FATAL, "Cannot open %s", fullname);
	/*
	 * Pop to previous file
	 */
	ParseEOF(1);
    } else {
	Var_Append(".MAKEFILE_LIST", fullname, VAR_GLOBAL);
    }
}
#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.F is closed. The includes list is shortened.
 *	curFile.lineno, curFile.F, and curFile.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_Append(".MAKEFILE_LIST", "..", VAR_GLOBAL);
	return (DONE);
    }

    ifile = Lst_DeQueue(&includes);
    free(curFile.fname);
    if (opened && curFile.F) {
	fclose(curFile.F);
	Var_Append(".MAKEFILE_LIST", "..", VAR_GLOBAL);
    }
    if (curFile.p) {
	free(curFile.p->str);
	free(curFile.p);
    }
    memcpy(&curFile, ifile, sizeof(IFile));
    free(ifile);
    return (CONTINUE);
}

/*-
 *---------------------------------------------------------------------
 * ParseReadc  --
 *	Read a character from the current file
 *
 * Results:
 *	The character that was read
 *
 * Side Effects:
 *---------------------------------------------------------------------
 */
static 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 unless it begins with a dot (`.') and we're told to
 *	ignore such lines.
 */
static char *
ParseSkipLine(int skip, int keep_newline)
{
    char *line;
    int c, lastc;
    Buffer *buf;

    buf = Buf_Init(MAKE_BSIZE);

    do {
        Buf_Clear(buf);
        lastc = '\0';

        while (((c = ParseReadc()) != '\n' || lastc == '\\')
               && c != EOF) {
            if (skip && c == '#' && lastc != '\\') {
		/* let a comment be terminated even by an escaped \n.
		 * This is consistent to comment handling in ParseReadLine */
                while ((c = ParseReadc()) != '\n' && c != EOF)
		    ;
		break;
	    }
            if (c == '\n') {
                if (keep_newline)
                    Buf_AddByte(buf, (Byte)c);
                else
                    Buf_ReplaceLastByte(buf, (Byte)' ');
                curFile.lineno++;

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

                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 = Buf_Data(buf);
    } 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		  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 (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();
			} 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;
	    default:
		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 = Buf_Peel(buf);

	/*
	 * 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:
		if (For_Eval(line)) {
		    int ok;
		    free(line);
		    lineno = curFile.lineno;
		    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;
	    default:
		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)
{
	const LstNode	*ln;

	if (inLine) {
		LST_FOREACH(ln, &targets) {
			if (((const GNode *)Lst_Datum(ln))->type & OP_TRANSFORM)
				Suff_EndTransform(Lst_Datum(ln));
		}
		Lst_Destroy(&targets, ParseHasCommands);
		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
 *
 * 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(char *name, FILE *stream)
{
    char	  *cp,		/* pointer into the line */
                  *line;	/* the line we're working on */
    Buffer	  *buf;

    inLine = FALSE;
    curFile.fname = name;
    curFile.F = stream;
    curFile.lineno = 0;
    fatals = 0;

    Var_Append(".MAKEFILE_LIST", name, VAR_GLOBAL);

    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) {
		    ParseDoInclude(cp + 7);
		    goto nextLine;
		} else if (strncmp(cp, "error", 5) == 0) {
		    ParseDoError(cp + 5);
	            goto nextLine;
		} else if (strncmp(cp, "warning", 7) == 0) {
		    ParseDoWarning(cp + 7);
	            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';

		    buf = Var_Subst(NULL, cp, VAR_CMD, FALSE);
		    cp = Buf_Peel(buf);

		    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.
		 */
		for (cp = line + 1; isspace((unsigned char)*cp); cp++) {
		    continue;
		}
		if (*cp) {
		    if (inLine) {
			LstNode	*ln;
			GNode	*gn;

			/*
			 * 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(ln, &targets) {
			    gn = Lst_Datum(ln);

			    /* if target already supplied, ignore commands */
			    if (!(gn->type & OP_HAS_COMMANDS))
				Lst_AtEnd(&gn->commands, cp);
			    else
				Parse_Error(PARSE_WARNING, "duplicate script "
				    "for target \"%s\" ignored", gn->name);
			}
			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]) &&
		       strchr(line, ':') == NULL) {
		/*
		 * It's an S3/S5-style "include".
		 */
		ParseTraditionalInclude(line + 7);
		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.
		 */
		cp = line;
		if (isspace((unsigned char)line[0])) {
		    while ((*cp != '\0') && isspace((unsigned char)*cp)) {
			cp++;
		    }
		    if (*cp == '\0') {
			goto nextLine;
		    }
		}

		ParseFinishLine();

		buf = Var_Subst(NULL, line, VAR_CMD, TRUE);
		cp = Buf_Peel(buf);

		free(line);
		line = cp;

		/*
		 * Need a non-circular list for the target nodes
		 */
		Lst_Destroy(&targets, NOFREE);
		inLine = TRUE;

		ParseDoDependency(line);
	    }

	    nextLine:

	    free(line);
	}

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

    ParseFinishLine();

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

    if (fatals)
	errx(1, "fatal errors encountered -- cannot continue");
}

/*-
 *---------------------------------------------------------------------
 * Parse_Init --
 *	initialize the parsing module
 *
 * Results:
 *	none
 *
 * Side Effects:
 *	the parseIncPath list is initialized...
 *---------------------------------------------------------------------
 */
void
Parse_Init(void)
{

    mainNode = NULL;
}

/*-
 *-----------------------------------------------------------------------
 * 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.
 *
 *-----------------------------------------------------------------------
 */
void
Parse_MainName(Lst *listmain)
{

    if (mainNode == NULL) {
	Punt("no target to make.");
    	/*NOTREACHED*/
    } else if (mainNode->type & OP_DOUBLEDEP) {
	Lst_AtEnd(listmain, mainNode);
	Lst_Concat(listmain, &mainNode->cohorts, LST_CONCNEW);
    }
    else
	Lst_AtEnd(listmain, mainNode);
}