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parse.c revision 1.7
      1 /*
      2  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
      3  * Copyright (c) 1988, 1989 by Adam de Boor
      4  * Copyright (c) 1989 by Berkeley Softworks
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Adam de Boor.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  */
     38 
     39 #ifndef lint
     40 /* from: static char sccsid[] = "@(#)parse.c	5.18 (Berkeley) 2/19/91"; */
     41 static char *rcsid = "$Id: parse.c,v 1.7 1994/03/07 22:22:05 cgd Exp $";
     42 #endif /* not lint */
     43 
     44 /*-
     45  * parse.c --
     46  *	Functions to parse a makefile.
     47  *
     48  *	One function, Parse_Init, must be called before any functions
     49  *	in this module are used. After that, the function Parse_File is the
     50  *	main entry point and controls most of the other functions in this
     51  *	module.
     52  *
     53  *	Most important structures are kept in Lsts. Directories for
     54  *	the #include "..." function are kept in the 'parseIncPath' Lst, while
     55  *	those for the #include <...> are kept in the 'sysIncPath' Lst. The
     56  *	targets currently being defined are kept in the 'targets' Lst.
     57  *
     58  *	The variables 'fname' and 'lineno' are used to track the name
     59  *	of the current file and the line number in that file so that error
     60  *	messages can be more meaningful.
     61  *
     62  * Interface:
     63  *	Parse_Init	    	    Initialization function which must be
     64  *	    	  	    	    called before anything else in this module
     65  *	    	  	    	    is used.
     66  *
     67  *	Parse_File	    	    Function used to parse a makefile. It must
     68  *	    	  	    	    be given the name of the file, which should
     69  *	    	  	    	    already have been opened, and a function
     70  *	    	  	    	    to call to read a character from the file.
     71  *
     72  *	Parse_IsVar	    	    Returns TRUE if the given line is a
     73  *	    	  	    	    variable assignment. Used by MainParseArgs
     74  *	    	  	    	    to determine if an argument is a target
     75  *	    	  	    	    or a variable assignment. Used internally
     76  *	    	  	    	    for pretty much the same thing...
     77  *
     78  *	Parse_Error	    	    Function called when an error occurs in
     79  *	    	  	    	    parsing. Used by the variable and
     80  *	    	  	    	    conditional modules.
     81  *	Parse_MainName	    	    Returns a Lst of the main target to create.
     82  */
     83 
     84 #if __STDC__
     85 #include <stdarg.h>
     86 #else
     87 #include <varargs.h>
     88 #endif
     89 #include <stdio.h>
     90 #include <ctype.h>
     91 #include <errno.h>
     92 #include <sys/wait.h>
     93 #include "make.h"
     94 #include "hash.h"
     95 #include "dir.h"
     96 #include "job.h"
     97 #include "buf.h"
     98 #include "pathnames.h"
     99 
    100 /*
    101  * These values are returned by ParseEOF to tell Parse_File whether to
    102  * CONTINUE parsing, i.e. it had only reached the end of an include file,
    103  * or if it's DONE.
    104  */
    105 #define	CONTINUE	1
    106 #define	DONE		0
    107 static Lst     	    targets;	/* targets we're working on */
    108 static Boolean	    inLine;	/* true if currently in a dependency
    109 				 * line or its commands */
    110 typedef struct {
    111     char *str;
    112     char *ptr;
    113 } PTR;
    114 
    115 static char    	    *fname;	/* name of current file (for errors) */
    116 static int          lineno;	/* line number in current file */
    117 static FILE   	    *curFILE = NULL; 	/* current makefile */
    118 
    119 static PTR 	    *curPTR = NULL; 	/* current makefile */
    120 
    121 static int	    fatals = 0;
    122 
    123 static GNode	    *mainNode;	/* The main target to create. This is the
    124 				 * first target on the first dependency
    125 				 * line in the first makefile */
    126 /*
    127  * Definitions for handling #include specifications
    128  */
    129 typedef struct IFile {
    130     char           *fname;	    /* name of previous file */
    131     int             lineno;	    /* saved line number */
    132     FILE *          F;		    /* the open stream */
    133     PTR *	    p;	    	    /* the char pointer */
    134 } IFile;
    135 
    136 static Lst      includes;  	/* stack of IFiles generated by
    137 				 * #includes */
    138 Lst         	parseIncPath;	/* list of directories for "..." includes */
    139 Lst         	sysIncPath;	/* list of directories for <...> includes */
    140 
    141 /*-
    142  * specType contains the SPECial TYPE of the current target. It is
    143  * Not if the target is unspecial. If it *is* special, however, the children
    144  * are linked as children of the parent but not vice versa. This variable is
    145  * set in ParseDoDependency
    146  */
    147 typedef enum {
    148     Begin,  	    /* .BEGIN */
    149     Default,	    /* .DEFAULT */
    150     End,    	    /* .END */
    151     Ignore,	    /* .IGNORE */
    152     Includes,	    /* .INCLUDES */
    153     Interrupt,	    /* .INTERRUPT */
    154     Libs,	    /* .LIBS */
    155     MFlags,	    /* .MFLAGS or .MAKEFLAGS */
    156     Main,	    /* .MAIN and we don't have anything user-specified to
    157 		     * make */
    158     NoExport,	    /* .NOEXPORT */
    159     Not,	    /* Not special */
    160     NotParallel,    /* .NOTPARALELL */
    161     Null,   	    /* .NULL */
    162     Order,  	    /* .ORDER */
    163     ExPath,	    /* .PATH */
    164     Precious,	    /* .PRECIOUS */
    165     ExShell,	    /* .SHELL */
    166     Silent,	    /* .SILENT */
    167     SingleShell,    /* .SINGLESHELL */
    168     Suffixes,	    /* .SUFFIXES */
    169     Attribute	    /* Generic attribute */
    170 } ParseSpecial;
    171 
    172 static ParseSpecial specType;
    173 
    174 /*
    175  * Predecessor node for handling .ORDER. Initialized to NILGNODE when .ORDER
    176  * seen, then set to each successive source on the line.
    177  */
    178 static GNode	*predecessor;
    179 
    180 /*
    181  * The parseKeywords table is searched using binary search when deciding
    182  * if a target or source is special. The 'spec' field is the ParseSpecial
    183  * type of the keyword ("Not" if the keyword isn't special as a target) while
    184  * the 'op' field is the operator to apply to the list of targets if the
    185  * keyword is used as a source ("0" if the keyword isn't special as a source)
    186  */
    187 static struct {
    188     char    	  *name;    	/* Name of keyword */
    189     ParseSpecial  spec;	    	/* Type when used as a target */
    190     int	    	  op;	    	/* Operator when used as a source */
    191 } parseKeywords[] = {
    192 { ".BEGIN", 	  Begin,    	0 },
    193 { ".DEFAULT",	  Default,  	0 },
    194 { ".OPTIONAL",	  Attribute,   	OP_OPTIONAL },
    195 { ".END",   	  End,	    	0 },
    196 { ".EXEC",	  Attribute,   	OP_EXEC },
    197 { ".IGNORE",	  Ignore,   	OP_IGNORE },
    198 { ".INCLUDES",	  Includes, 	0 },
    199 { ".INTERRUPT",	  Interrupt,	0 },
    200 { ".INVISIBLE",	  Attribute,   	OP_INVISIBLE },
    201 { ".JOIN",  	  Attribute,   	OP_JOIN },
    202 { ".LIBS",  	  Libs,	    	0 },
    203 { ".MAIN",	  Main,		0 },
    204 { ".MAKE",  	  Attribute,   	OP_MAKE },
    205 { ".MAKEFLAGS",	  MFlags,   	0 },
    206 { ".MFLAGS",	  MFlags,   	0 },
    207 { ".NOTMAIN",	  Attribute,   	OP_NOTMAIN },
    208 { ".NOTPARALLEL", NotParallel,	0 },
    209 { ".NULL",  	  Null,	    	0 },
    210 { ".ORDER", 	  Order,    	0 },
    211 { ".PATH",	  ExPath,	0 },
    212 { ".PRECIOUS",	  Precious, 	OP_PRECIOUS },
    213 { ".RECURSIVE",	  Attribute,	OP_MAKE },
    214 { ".SHELL", 	  ExShell,    	0 },
    215 { ".SILENT",	  Silent,   	OP_SILENT },
    216 { ".SINGLESHELL", SingleShell,	0 },
    217 { ".SUFFIXES",	  Suffixes, 	0 },
    218 { ".USE",   	  Attribute,   	OP_USE },
    219 };
    220 
    221 static int ParseFindKeyword __P((char *));
    222 static int ParseLinkSrc __P((GNode *, GNode *));
    223 static int ParseDoOp __P((GNode *, int));
    224 static void ParseDoSrc __P((int, char *));
    225 static int ParseFindMain __P((GNode *));
    226 static int ParseAddDir __P((Lst, char *));
    227 static int ParseClearPath __P((Lst));
    228 static void ParseDoDependency __P((char *));
    229 static int ParseAddCmd __P((GNode *, char *));
    230 static int ParseReadc __P((void));
    231 static void ParseUnreadc __P((int));
    232 static int ParseHasCommands __P((GNode *));
    233 static void ParseDoInclude __P((char *));
    234 #ifdef SYSVINCLUDE
    235 static void ParseTraditionalInclude __P((char *));
    236 #endif
    237 static int ParseEOF __P((int));
    238 static char *ParseReadLine __P((void));
    239 static char *ParseSkipLine __P((int));
    240 static void ParseFinishLine __P((void));
    241 
    242 /*-
    243  *----------------------------------------------------------------------
    244  * ParseFindKeyword --
    245  *	Look in the table of keywords for one matching the given string.
    246  *
    247  * Results:
    248  *	The index of the keyword, or -1 if it isn't there.
    249  *
    250  * Side Effects:
    251  *	None
    252  *----------------------------------------------------------------------
    253  */
    254 static int
    255 ParseFindKeyword (str)
    256     char	    *str;		/* String to find */
    257 {
    258     register int    start,
    259 		    end,
    260 		    cur;
    261     register int    diff;
    262 
    263     start = 0;
    264     end = (sizeof(parseKeywords)/sizeof(parseKeywords[0])) - 1;
    265 
    266     do {
    267 	cur = start + ((end - start) / 2);
    268 	diff = strcmp (str, parseKeywords[cur].name);
    269 
    270 	if (diff == 0) {
    271 	    return (cur);
    272 	} else if (diff < 0) {
    273 	    end = cur - 1;
    274 	} else {
    275 	    start = cur + 1;
    276 	}
    277     } while (start <= end);
    278     return (-1);
    279 }
    280 
    281 /*-
    282  * Parse_Error  --
    283  *	Error message abort function for parsing. Prints out the context
    284  *	of the error (line number and file) as well as the message with
    285  *	two optional arguments.
    286  *
    287  * Results:
    288  *	None
    289  *
    290  * Side Effects:
    291  *	"fatals" is incremented if the level is PARSE_FATAL.
    292  */
    293 /* VARARGS */
    294 void
    295 #if __STDC__
    296 Parse_Error(int type, char *fmt, ...)
    297 #else
    298 Parse_Error(va_alist)
    299 	va_dcl
    300 #endif
    301 {
    302 	va_list ap;
    303 #if __STDC__
    304 	va_start(ap, fmt);
    305 #else
    306 	int type;		/* Error type (PARSE_WARNING, PARSE_FATAL) */
    307 	char *fmt;
    308 
    309 	va_start(ap);
    310 	type = va_arg(ap, int);
    311 	fmt = va_arg(ap, char *);
    312 #endif
    313 
    314 	(void)fprintf(stderr, "\"%s\", line %d: ", fname, lineno);
    315 	if (type == PARSE_WARNING)
    316 		(void)fprintf(stderr, "warning: ");
    317 	(void)vfprintf(stderr, fmt, ap);
    318 	va_end(ap);
    319 	(void)fprintf(stderr, "\n");
    320 	(void)fflush(stderr);
    321 	if (type == PARSE_FATAL)
    322 		fatals += 1;
    323 }
    324 
    325 /*-
    326  *---------------------------------------------------------------------
    327  * ParseLinkSrc  --
    328  *	Link the parent node to its new child. Used in a Lst_ForEach by
    329  *	ParseDoDependency. If the specType isn't 'Not', the parent
    330  *	isn't linked as a parent of the child.
    331  *
    332  * Results:
    333  *	Always = 0
    334  *
    335  * Side Effects:
    336  *	New elements are added to the parents list of cgn and the
    337  *	children list of cgn. the unmade field of pgn is updated
    338  *	to reflect the additional child.
    339  *---------------------------------------------------------------------
    340  */
    341 static int
    342 ParseLinkSrc (pgn, cgn)
    343     GNode          *pgn;	/* The parent node */
    344     GNode          *cgn;	/* The child node */
    345 {
    346     if (Lst_Member (pgn->children, (ClientData)cgn) == NILLNODE) {
    347 	(void)Lst_AtEnd (pgn->children, (ClientData)cgn);
    348 	if (specType == Not) {
    349 	    (void)Lst_AtEnd (cgn->parents, (ClientData)pgn);
    350 	}
    351 	pgn->unmade += 1;
    352     }
    353     return (0);
    354 }
    355 
    356 /*-
    357  *---------------------------------------------------------------------
    358  * ParseDoOp  --
    359  *	Apply the parsed operator to the given target node. Used in a
    360  *	Lst_ForEach call by ParseDoDependency once all targets have
    361  *	been found and their operator parsed. If the previous and new
    362  *	operators are incompatible, a major error is taken.
    363  *
    364  * Results:
    365  *	Always 0
    366  *
    367  * Side Effects:
    368  *	The type field of the node is altered to reflect any new bits in
    369  *	the op.
    370  *---------------------------------------------------------------------
    371  */
    372 static int
    373 ParseDoOp (gn, op)
    374     GNode          *gn;		/* The node to which the operator is to be
    375 				 * applied */
    376     int             op;		/* The operator to apply */
    377 {
    378     /*
    379      * If the dependency mask of the operator and the node don't match and
    380      * the node has actually had an operator applied to it before, and
    381      * the operator actually has some dependency information in it, complain.
    382      */
    383     if (((op & OP_OPMASK) != (gn->type & OP_OPMASK)) &&
    384 	!OP_NOP(gn->type) && !OP_NOP(op))
    385     {
    386 	Parse_Error (PARSE_FATAL, "Inconsistent operator for %s", gn->name);
    387 	return (1);
    388     }
    389 
    390     if ((op == OP_DOUBLEDEP) && ((gn->type & OP_OPMASK) == OP_DOUBLEDEP)) {
    391 	/*
    392 	 * If the node was the object of a :: operator, we need to create a
    393 	 * new instance of it for the children and commands on this dependency
    394 	 * line. The new instance is placed on the 'cohorts' list of the
    395 	 * initial one (note the initial one is not on its own cohorts list)
    396 	 * and the new instance is linked to all parents of the initial
    397 	 * instance.
    398 	 */
    399 	register GNode	*cohort;
    400 	LstNode	    	ln;
    401 
    402 	cohort = Targ_NewGN(gn->name);
    403 	/*
    404 	 * Duplicate links to parents so graph traversal is simple. Perhaps
    405 	 * some type bits should be duplicated?
    406 	 *
    407 	 * Make the cohort invisible as well to avoid duplicating it into
    408 	 * other variables. True, parents of this target won't tend to do
    409 	 * anything with their local variables, but better safe than
    410 	 * sorry.
    411 	 */
    412 	Lst_ForEach(gn->parents, ParseLinkSrc, (ClientData)cohort);
    413 	cohort->type = OP_DOUBLEDEP|OP_INVISIBLE;
    414 	(void)Lst_AtEnd(gn->cohorts, (ClientData)cohort);
    415 
    416 	/*
    417 	 * Replace the node in the targets list with the new copy
    418 	 */
    419 	ln = Lst_Member(targets, (ClientData)gn);
    420 	Lst_Replace(ln, (ClientData)cohort);
    421 	gn = cohort;
    422     }
    423     /*
    424      * We don't want to nuke any previous flags (whatever they were) so we
    425      * just OR the new operator into the old
    426      */
    427     gn->type |= op;
    428 
    429     return (0);
    430 }
    431 
    432 /*-
    433  *---------------------------------------------------------------------
    434  * ParseDoSrc  --
    435  *	Given the name of a source, figure out if it is an attribute
    436  *	and apply it to the targets if it is. Else decide if there is
    437  *	some attribute which should be applied *to* the source because
    438  *	of some special target and apply it if so. Otherwise, make the
    439  *	source be a child of the targets in the list 'targets'
    440  *
    441  * Results:
    442  *	None
    443  *
    444  * Side Effects:
    445  *	Operator bits may be added to the list of targets or to the source.
    446  *	The targets may have a new source added to their lists of children.
    447  *---------------------------------------------------------------------
    448  */
    449 static void
    450 ParseDoSrc (tOp, src)
    451     int		tOp;	/* operator (if any) from special targets */
    452     char	*src;	/* name of the source to handle */
    453 {
    454     int		op;	/* operator (if any) from special source */
    455     GNode	*gn;
    456 
    457     op = 0;
    458     if (*src == '.' && isupper (src[1])) {
    459 	int keywd = ParseFindKeyword(src);
    460 	if (keywd != -1) {
    461 	    op = parseKeywords[keywd].op;
    462 	}
    463     }
    464     if (op != 0) {
    465 	Lst_ForEach (targets, ParseDoOp, (ClientData)op);
    466     } else if (specType == Main) {
    467 	/*
    468 	 * If we have noted the existence of a .MAIN, it means we need
    469 	 * to add the sources of said target to the list of things
    470 	 * to create. The string 'src' is likely to be free, so we
    471 	 * must make a new copy of it. Note that this will only be
    472 	 * invoked if the user didn't specify a target on the command
    473 	 * line. This is to allow #ifmake's to succeed, or something...
    474 	 */
    475 	(void) Lst_AtEnd (create, (ClientData)strdup(src));
    476 	/*
    477 	 * Add the name to the .TARGETS variable as well, so the user cna
    478 	 * employ that, if desired.
    479 	 */
    480 	Var_Append(".TARGETS", src, VAR_GLOBAL);
    481     } else if (specType == Order) {
    482 	/*
    483 	 * Create proper predecessor/successor links between the previous
    484 	 * source and the current one.
    485 	 */
    486 	gn = Targ_FindNode(src, TARG_CREATE);
    487 	if (predecessor != NILGNODE) {
    488 	    (void)Lst_AtEnd(predecessor->successors, (ClientData)gn);
    489 	    (void)Lst_AtEnd(gn->preds, (ClientData)predecessor);
    490 	}
    491 	/*
    492 	 * The current source now becomes the predecessor for the next one.
    493 	 */
    494 	predecessor = gn;
    495     } else {
    496 	/*
    497 	 * If the source is not an attribute, we need to find/create
    498 	 * a node for it. After that we can apply any operator to it
    499 	 * from a special target or link it to its parents, as
    500 	 * appropriate.
    501 	 *
    502 	 * In the case of a source that was the object of a :: operator,
    503 	 * the attribute is applied to all of its instances (as kept in
    504 	 * the 'cohorts' list of the node) or all the cohorts are linked
    505 	 * to all the targets.
    506 	 */
    507 	gn = Targ_FindNode (src, TARG_CREATE);
    508 	if (tOp) {
    509 	    gn->type |= tOp;
    510 	} else {
    511 	    Lst_ForEach (targets, ParseLinkSrc, (ClientData)gn);
    512 	}
    513 	if ((gn->type & OP_OPMASK) == OP_DOUBLEDEP) {
    514 	    register GNode  	*cohort;
    515 	    register LstNode	ln;
    516 
    517 	    for (ln=Lst_First(gn->cohorts); ln != NILLNODE; ln = Lst_Succ(ln)){
    518 		cohort = (GNode *)Lst_Datum(ln);
    519 		if (tOp) {
    520 		    cohort->type |= tOp;
    521 		} else {
    522 		    Lst_ForEach(targets, ParseLinkSrc, (ClientData)cohort);
    523 		}
    524 	    }
    525 	}
    526     }
    527 }
    528 
    529 /*-
    530  *-----------------------------------------------------------------------
    531  * ParseFindMain --
    532  *	Find a real target in the list and set it to be the main one.
    533  *	Called by ParseDoDependency when a main target hasn't been found
    534  *	yet.
    535  *
    536  * Results:
    537  *	0 if main not found yet, 1 if it is.
    538  *
    539  * Side Effects:
    540  *	mainNode is changed and Targ_SetMain is called.
    541  *
    542  *-----------------------------------------------------------------------
    543  */
    544 static int
    545 ParseFindMain(gn)
    546     GNode   	  *gn;	    /* Node to examine */
    547 {
    548     if ((gn->type & (OP_NOTMAIN|OP_USE|OP_EXEC|OP_TRANSFORM)) == 0) {
    549 	mainNode = gn;
    550 	Targ_SetMain(gn);
    551 	return (1);
    552     } else {
    553 	return (0);
    554     }
    555 }
    556 
    557 /*-
    558  *-----------------------------------------------------------------------
    559  * ParseAddDir --
    560  *	Front-end for Dir_AddDir to make sure Lst_ForEach keeps going
    561  *
    562  * Results:
    563  *	=== 0
    564  *
    565  * Side Effects:
    566  *	See Dir_AddDir.
    567  *
    568  *-----------------------------------------------------------------------
    569  */
    570 static int
    571 ParseAddDir(path, name)
    572     Lst	    path;
    573     char    *name;
    574 {
    575     Dir_AddDir(path, name);
    576     return(0);
    577 }
    578 
    579 /*-
    580  *-----------------------------------------------------------------------
    581  * ParseClearPath --
    582  *	Front-end for Dir_ClearPath to make sure Lst_ForEach keeps going
    583  *
    584  * Results:
    585  *	=== 0
    586  *
    587  * Side Effects:
    588  *	See Dir_ClearPath
    589  *
    590  *-----------------------------------------------------------------------
    591  */
    592 static int
    593 ParseClearPath(path)
    594     Lst	    path;
    595 {
    596     Dir_ClearPath(path);
    597     return(0);
    598 }
    599 
    600 /*-
    601  *---------------------------------------------------------------------
    602  * ParseDoDependency  --
    603  *	Parse the dependency line in line.
    604  *
    605  * Results:
    606  *	None
    607  *
    608  * Side Effects:
    609  *	The nodes of the sources are linked as children to the nodes of the
    610  *	targets. Some nodes may be created.
    611  *
    612  *	We parse a dependency line by first extracting words from the line and
    613  * finding nodes in the list of all targets with that name. This is done
    614  * until a character is encountered which is an operator character. Currently
    615  * these are only ! and :. At this point the operator is parsed and the
    616  * pointer into the line advanced until the first source is encountered.
    617  * 	The parsed operator is applied to each node in the 'targets' list,
    618  * which is where the nodes found for the targets are kept, by means of
    619  * the ParseDoOp function.
    620  *	The sources are read in much the same way as the targets were except
    621  * that now they are expanded using the wildcarding scheme of the C-Shell
    622  * and all instances of the resulting words in the list of all targets
    623  * are found. Each of the resulting nodes is then linked to each of the
    624  * targets as one of its children.
    625  *	Certain targets are handled specially. These are the ones detailed
    626  * by the specType variable.
    627  *	The storing of transformation rules is also taken care of here.
    628  * A target is recognized as a transformation rule by calling
    629  * Suff_IsTransform. If it is a transformation rule, its node is gotten
    630  * from the suffix module via Suff_AddTransform rather than the standard
    631  * Targ_FindNode in the target module.
    632  *---------------------------------------------------------------------
    633  */
    634 static void
    635 ParseDoDependency (line)
    636     char           *line;	/* the line to parse */
    637 {
    638     register char  *cp;		/* our current position */
    639     register GNode *gn;		/* a general purpose temporary node */
    640     register int    op;		/* the operator on the line */
    641     char            savec;	/* a place to save a character */
    642     Lst    	    paths;   	/* List of search paths to alter when parsing
    643 				 * a list of .PATH targets */
    644     int	    	    tOp;    	/* operator from special target */
    645     Lst	    	    sources;	/* list of source names after expansion */
    646     Lst 	    curTargs;	/* list of target names to be found and added
    647 				 * to the targets list */
    648 
    649     tOp = 0;
    650 
    651     specType = Not;
    652     paths = (Lst)NULL;
    653 
    654     curTargs = Lst_Init(FALSE);
    655 
    656     do {
    657 	for (cp = line;
    658 	     *cp && !isspace (*cp) &&
    659 	     (*cp != '!') && (*cp != ':') && (*cp != '(');
    660 	     cp++)
    661 	{
    662 	    if (*cp == '$') {
    663 		/*
    664 		 * Must be a dynamic source (would have been expanded
    665 		 * otherwise), so call the Var module to parse the puppy
    666 		 * so we can safely advance beyond it...There should be
    667 		 * no errors in this, as they would have been discovered
    668 		 * in the initial Var_Subst and we wouldn't be here.
    669 		 */
    670 		int 	length;
    671 		Boolean	freeIt;
    672 		char	*result;
    673 
    674 		result=Var_Parse(cp, VAR_CMD, TRUE, &length, &freeIt);
    675 
    676 		if (freeIt) {
    677 		    free(result);
    678 		}
    679 		cp += length-1;
    680 	    }
    681 	    continue;
    682 	}
    683 	if (*cp == '(') {
    684 	    /*
    685 	     * Archives must be handled specially to make sure the OP_ARCHV
    686 	     * flag is set in their 'type' field, for one thing, and because
    687 	     * things like "archive(file1.o file2.o file3.o)" are permissible.
    688 	     * Arch_ParseArchive will set 'line' to be the first non-blank
    689 	     * after the archive-spec. It creates/finds nodes for the members
    690 	     * and places them on the given list, returning SUCCESS if all
    691 	     * went well and FAILURE if there was an error in the
    692 	     * specification. On error, line should remain untouched.
    693 	     */
    694 	    if (Arch_ParseArchive (&line, targets, VAR_CMD) != SUCCESS) {
    695 		Parse_Error (PARSE_FATAL,
    696 			     "Error in archive specification: \"%s\"", line);
    697 		return;
    698 	    } else {
    699 		continue;
    700 	    }
    701 	}
    702 	savec = *cp;
    703 
    704 	if (!*cp) {
    705 	    /*
    706 	     * Ending a dependency line without an operator is a Bozo
    707 	     * no-no
    708 	     */
    709 	    Parse_Error (PARSE_FATAL, "Need an operator");
    710 	    return;
    711 	}
    712 	*cp = '\0';
    713 	/*
    714 	 * Have a word in line. See if it's a special target and set
    715 	 * specType to match it.
    716 	 */
    717 	if (*line == '.' && isupper (line[1])) {
    718 	    /*
    719 	     * See if the target is a special target that must have it
    720 	     * or its sources handled specially.
    721 	     */
    722 	    int keywd = ParseFindKeyword(line);
    723 	    if (keywd != -1) {
    724 		if (specType == ExPath && parseKeywords[keywd].spec != ExPath) {
    725 		    Parse_Error(PARSE_FATAL, "Mismatched special targets");
    726 		    return;
    727 		}
    728 
    729 		specType = parseKeywords[keywd].spec;
    730 		tOp = parseKeywords[keywd].op;
    731 
    732 		/*
    733 		 * Certain special targets have special semantics:
    734 		 *	.PATH		Have to set the dirSearchPath
    735 		 *			variable too
    736 		 *	.MAIN		Its sources are only used if
    737 		 *			nothing has been specified to
    738 		 *			create.
    739 		 *	.DEFAULT    	Need to create a node to hang
    740 		 *			commands on, but we don't want
    741 		 *			it in the graph, nor do we want
    742 		 *			it to be the Main Target, so we
    743 		 *			create it, set OP_NOTMAIN and
    744 		 *			add it to the list, setting
    745 		 *			DEFAULT to the new node for
    746 		 *			later use. We claim the node is
    747 		 *	    	    	A transformation rule to make
    748 		 *	    	    	life easier later, when we'll
    749 		 *	    	    	use Make_HandleUse to actually
    750 		 *	    	    	apply the .DEFAULT commands.
    751 		 *	.BEGIN
    752 		 *	.END
    753 		 *	.INTERRUPT  	Are not to be considered the
    754 		 *			main target.
    755 		 *  	.NOTPARALLEL	Make only one target at a time.
    756 		 *  	.SINGLESHELL	Create a shell for each command.
    757 		 *  	.ORDER	    	Must set initial predecessor to NIL
    758 		 */
    759 		switch (specType) {
    760 		    case ExPath:
    761 			if (paths == NULL) {
    762 			    paths = Lst_Init(FALSE);
    763 			}
    764 			(void)Lst_AtEnd(paths, (ClientData)dirSearchPath);
    765 			break;
    766 		    case Main:
    767 			if (!Lst_IsEmpty(create)) {
    768 			    specType = Not;
    769 			}
    770 			break;
    771 		    case Begin:
    772 		    case End:
    773 		    case Interrupt:
    774 			gn = Targ_FindNode(line, TARG_CREATE);
    775 			gn->type |= OP_NOTMAIN;
    776 			(void)Lst_AtEnd(targets, (ClientData)gn);
    777 			break;
    778 		    case Default:
    779 			gn = Targ_NewGN(".DEFAULT");
    780 			gn->type |= (OP_NOTMAIN|OP_TRANSFORM);
    781 			(void)Lst_AtEnd(targets, (ClientData)gn);
    782 			DEFAULT = gn;
    783 			break;
    784 		    case NotParallel:
    785 		    {
    786 			extern int  maxJobs;
    787 
    788 			maxJobs = 1;
    789 			break;
    790 		    }
    791 		    case SingleShell:
    792 			compatMake = 1;
    793 			break;
    794 		    case Order:
    795 			predecessor = NILGNODE;
    796 			break;
    797 		    default:
    798 			break;
    799 		}
    800 	    } else if (strncmp (line, ".PATH", 5) == 0) {
    801 		/*
    802 		 * .PATH<suffix> has to be handled specially.
    803 		 * Call on the suffix module to give us a path to
    804 		 * modify.
    805 		 */
    806 		Lst 	path;
    807 
    808 		specType = ExPath;
    809 		path = Suff_GetPath (&line[5]);
    810 		if (path == NILLST) {
    811 		    Parse_Error (PARSE_FATAL,
    812 				 "Suffix '%s' not defined (yet)",
    813 				 &line[5]);
    814 		    return;
    815 		} else {
    816 		    if (paths == (Lst)NULL) {
    817 			paths = Lst_Init(FALSE);
    818 		    }
    819 		    (void)Lst_AtEnd(paths, (ClientData)path);
    820 		}
    821 	    }
    822 	}
    823 
    824 	/*
    825 	 * Have word in line. Get or create its node and stick it at
    826 	 * the end of the targets list
    827 	 */
    828 	if ((specType == Not) && (*line != '\0')) {
    829 	    if (Dir_HasWildcards(line)) {
    830 		/*
    831 		 * Targets are to be sought only in the current directory,
    832 		 * so create an empty path for the thing. Note we need to
    833 		 * use Dir_Destroy in the destruction of the path as the
    834 		 * Dir module could have added a directory to the path...
    835 		 */
    836 		Lst	    emptyPath = Lst_Init(FALSE);
    837 
    838 		Dir_Expand(line, emptyPath, curTargs);
    839 
    840 		Lst_Destroy(emptyPath, Dir_Destroy);
    841 	    } else {
    842 		/*
    843 		 * No wildcards, but we want to avoid code duplication,
    844 		 * so create a list with the word on it.
    845 		 */
    846 		(void)Lst_AtEnd(curTargs, (ClientData)line);
    847 	    }
    848 
    849 	    while(!Lst_IsEmpty(curTargs)) {
    850 		char	*targName = (char *)Lst_DeQueue(curTargs);
    851 
    852 		if (!Suff_IsTransform (targName)) {
    853 		    gn = Targ_FindNode (targName, TARG_CREATE);
    854 		} else {
    855 		    gn = Suff_AddTransform (targName);
    856 		}
    857 
    858 		(void)Lst_AtEnd (targets, (ClientData)gn);
    859 	    }
    860 	} else if (specType == ExPath && *line != '.' && *line != '\0') {
    861 	    Parse_Error(PARSE_WARNING, "Extra target (%s) ignored", line);
    862 	}
    863 
    864 	*cp = savec;
    865 	/*
    866 	 * If it is a special type and not .PATH, it's the only target we
    867 	 * allow on this line...
    868 	 */
    869 	if (specType != Not && specType != ExPath) {
    870 	    Boolean warn = FALSE;
    871 
    872 	    while ((*cp != '!') && (*cp != ':') && *cp) {
    873 		if (*cp != ' ' && *cp != '\t') {
    874 		    warn = TRUE;
    875 		}
    876 		cp++;
    877 	    }
    878 	    if (warn) {
    879 		Parse_Error(PARSE_WARNING, "Extra target ignored");
    880 	    }
    881 	} else {
    882 	    while (*cp && isspace (*cp)) {
    883 		cp++;
    884 	    }
    885 	}
    886 	line = cp;
    887     } while ((*line != '!') && (*line != ':') && *line);
    888 
    889     /*
    890      * Don't need the list of target names anymore...
    891      */
    892     Lst_Destroy(curTargs, NOFREE);
    893 
    894     if (!Lst_IsEmpty(targets)) {
    895 	switch(specType) {
    896 	    default:
    897 		Parse_Error(PARSE_WARNING, "Special and mundane targets don't mix. Mundane ones ignored");
    898 		break;
    899 	    case Default:
    900 	    case Begin:
    901 	    case End:
    902 	    case Interrupt:
    903 		/*
    904 		 * These four create nodes on which to hang commands, so
    905 		 * targets shouldn't be empty...
    906 		 */
    907 	    case Not:
    908 		/*
    909 		 * Nothing special here -- targets can be empty if it wants.
    910 		 */
    911 		break;
    912 	}
    913     }
    914 
    915     /*
    916      * Have now parsed all the target names. Must parse the operator next. The
    917      * result is left in  op .
    918      */
    919     if (*cp == '!') {
    920 	op = OP_FORCE;
    921     } else if (*cp == ':') {
    922 	if (cp[1] == ':') {
    923 	    op = OP_DOUBLEDEP;
    924 	    cp++;
    925 	} else {
    926 	    op = OP_DEPENDS;
    927 	}
    928     } else {
    929 	Parse_Error (PARSE_FATAL, "Missing dependency operator");
    930 	return;
    931     }
    932 
    933     cp++;			/* Advance beyond operator */
    934 
    935     Lst_ForEach (targets, ParseDoOp, (ClientData)op);
    936 
    937     /*
    938      * Get to the first source
    939      */
    940     while (*cp && isspace (*cp)) {
    941 	cp++;
    942     }
    943     line = cp;
    944 
    945     /*
    946      * Several special targets take different actions if present with no
    947      * sources:
    948      *	a .SUFFIXES line with no sources clears out all old suffixes
    949      *	a .PRECIOUS line makes all targets precious
    950      *	a .IGNORE line ignores errors for all targets
    951      *	a .SILENT line creates silence when making all targets
    952      *	a .PATH removes all directories from the search path(s).
    953      */
    954     if (!*line) {
    955 	switch (specType) {
    956 	    case Suffixes:
    957 		Suff_ClearSuffixes ();
    958 		break;
    959 	    case Precious:
    960 		allPrecious = TRUE;
    961 		break;
    962 	    case Ignore:
    963 		ignoreErrors = TRUE;
    964 		break;
    965 	    case Silent:
    966 		beSilent = TRUE;
    967 		break;
    968 	    case ExPath:
    969 		Lst_ForEach(paths, ParseClearPath, (ClientData)NULL);
    970 		break;
    971 	    default:
    972 		break;
    973 	}
    974     } else if (specType == MFlags) {
    975 	/*
    976 	 * Call on functions in main.c to deal with these arguments and
    977 	 * set the initial character to a null-character so the loop to
    978 	 * get sources won't get anything
    979 	 */
    980 	Main_ParseArgLine (line);
    981 	*line = '\0';
    982     } else if (specType == ExShell) {
    983 	if (Job_ParseShell (line) != SUCCESS) {
    984 	    Parse_Error (PARSE_FATAL, "improper shell specification");
    985 	    return;
    986 	}
    987 	*line = '\0';
    988     } else if ((specType == NotParallel) || (specType == SingleShell)) {
    989 	*line = '\0';
    990     }
    991 
    992     /*
    993      * NOW GO FOR THE SOURCES
    994      */
    995     if ((specType == Suffixes) || (specType == ExPath) ||
    996 	(specType == Includes) || (specType == Libs) ||
    997 	(specType == Null))
    998     {
    999 	while (*line) {
   1000 	    /*
   1001 	     * If the target was one that doesn't take files as its sources
   1002 	     * but takes something like suffixes, we take each
   1003 	     * space-separated word on the line as a something and deal
   1004 	     * with it accordingly.
   1005 	     *
   1006 	     * If the target was .SUFFIXES, we take each source as a
   1007 	     * suffix and add it to the list of suffixes maintained by the
   1008 	     * Suff module.
   1009 	     *
   1010 	     * If the target was a .PATH, we add the source as a directory
   1011 	     * to search on the search path.
   1012 	     *
   1013 	     * If it was .INCLUDES, the source is taken to be the suffix of
   1014 	     * files which will be #included and whose search path should
   1015 	     * be present in the .INCLUDES variable.
   1016 	     *
   1017 	     * If it was .LIBS, the source is taken to be the suffix of
   1018 	     * files which are considered libraries and whose search path
   1019 	     * should be present in the .LIBS variable.
   1020 	     *
   1021 	     * If it was .NULL, the source is the suffix to use when a file
   1022 	     * has no valid suffix.
   1023 	     */
   1024 	    char  savec;
   1025 	    while (*cp && !isspace (*cp)) {
   1026 		cp++;
   1027 	    }
   1028 	    savec = *cp;
   1029 	    *cp = '\0';
   1030 	    switch (specType) {
   1031 		case Suffixes:
   1032 		    Suff_AddSuffix (line);
   1033 		    break;
   1034 		case ExPath:
   1035 		    Lst_ForEach(paths, ParseAddDir, (ClientData)line);
   1036 		    break;
   1037 		case Includes:
   1038 		    Suff_AddInclude (line);
   1039 		    break;
   1040 		case Libs:
   1041 		    Suff_AddLib (line);
   1042 		    break;
   1043 		case Null:
   1044 		    Suff_SetNull (line);
   1045 		    break;
   1046 		default:
   1047 		    break;
   1048 	    }
   1049 	    *cp = savec;
   1050 	    if (savec != '\0') {
   1051 		cp++;
   1052 	    }
   1053 	    while (*cp && isspace (*cp)) {
   1054 		cp++;
   1055 	    }
   1056 	    line = cp;
   1057 	}
   1058 	if (paths) {
   1059 	    Lst_Destroy(paths, NOFREE);
   1060 	}
   1061     } else {
   1062 	while (*line) {
   1063 	    /*
   1064 	     * The targets take real sources, so we must beware of archive
   1065 	     * specifications (i.e. things with left parentheses in them)
   1066 	     * and handle them accordingly.
   1067 	     */
   1068 	    while (*cp && !isspace (*cp)) {
   1069 		if ((*cp == '(') && (cp > line) && (cp[-1] != '$')) {
   1070 		    /*
   1071 		     * Only stop for a left parenthesis if it isn't at the
   1072 		     * start of a word (that'll be for variable changes
   1073 		     * later) and isn't preceded by a dollar sign (a dynamic
   1074 		     * source).
   1075 		     */
   1076 		    break;
   1077 		} else {
   1078 		    cp++;
   1079 		}
   1080 	    }
   1081 
   1082 	    if (*cp == '(') {
   1083 		GNode	  *gn;
   1084 
   1085 		sources = Lst_Init (FALSE);
   1086 		if (Arch_ParseArchive (&line, sources, VAR_CMD) != SUCCESS) {
   1087 		    Parse_Error (PARSE_FATAL,
   1088 				 "Error in source archive spec \"%s\"", line);
   1089 		    return;
   1090 		}
   1091 
   1092 		while (!Lst_IsEmpty (sources)) {
   1093 		    gn = (GNode *) Lst_DeQueue (sources);
   1094 		    ParseDoSrc (tOp, gn->name);
   1095 		}
   1096 		Lst_Destroy (sources, NOFREE);
   1097 		cp = line;
   1098 	    } else {
   1099 		if (*cp) {
   1100 		    *cp = '\0';
   1101 		    cp += 1;
   1102 		}
   1103 
   1104 		ParseDoSrc (tOp, line);
   1105 	    }
   1106 	    while (*cp && isspace (*cp)) {
   1107 		cp++;
   1108 	    }
   1109 	    line = cp;
   1110 	}
   1111     }
   1112 
   1113     if (mainNode == NILGNODE) {
   1114 	/*
   1115 	 * If we have yet to decide on a main target to make, in the
   1116 	 * absence of any user input, we want the first target on
   1117 	 * the first dependency line that is actually a real target
   1118 	 * (i.e. isn't a .USE or .EXEC rule) to be made.
   1119 	 */
   1120 	Lst_ForEach (targets, ParseFindMain, (ClientData)0);
   1121     }
   1122 
   1123 }
   1124 
   1125 /*-
   1126  *---------------------------------------------------------------------
   1127  * Parse_IsVar  --
   1128  *	Return TRUE if the passed line is a variable assignment. A variable
   1129  *	assignment consists of a single word followed by optional whitespace
   1130  *	followed by either a += or an = operator.
   1131  *	This function is used both by the Parse_File function and main when
   1132  *	parsing the command-line arguments.
   1133  *
   1134  * Results:
   1135  *	TRUE if it is. FALSE if it ain't
   1136  *
   1137  * Side Effects:
   1138  *	none
   1139  *---------------------------------------------------------------------
   1140  */
   1141 Boolean
   1142 Parse_IsVar (line)
   1143     register char  *line;	/* the line to check */
   1144 {
   1145     register Boolean wasSpace = FALSE;	/* set TRUE if found a space */
   1146     register Boolean haveName = FALSE;	/* Set TRUE if have a variable name */
   1147 
   1148     /*
   1149      * Skip to variable name
   1150      */
   1151     while ((*line == ' ') || (*line == '\t')) {
   1152 	line++;
   1153     }
   1154 
   1155     while (*line != '=') {
   1156 	if (*line == '\0') {
   1157 	    /*
   1158 	     * end-of-line -- can't be a variable assignment.
   1159 	     */
   1160 	    return (FALSE);
   1161 	} else if ((*line == ' ') || (*line == '\t')) {
   1162 	    /*
   1163 	     * there can be as much white space as desired so long as there is
   1164 	     * only one word before the operator
   1165 	     */
   1166 	    wasSpace = TRUE;
   1167 	} else if (wasSpace && haveName) {
   1168 	    /*
   1169 	     * Stop when an = operator is found.
   1170 	     */
   1171 	    if ((*line == '+') || (*line == ':') || (*line == '?') ||
   1172 		(*line == '!')) {
   1173 		break;
   1174 	    }
   1175 
   1176 	    /*
   1177 	     * This is the start of another word, so not assignment.
   1178 	     */
   1179 	    return (FALSE);
   1180 	} else {
   1181 	    haveName = TRUE;
   1182 	    wasSpace = FALSE;
   1183 	}
   1184 	line++;
   1185     }
   1186 
   1187     /*
   1188      * A final check: if we stopped on a +, ?, ! or :, the next character must
   1189      * be an = or it ain't a valid assignment
   1190      */
   1191     if (((*line == '+') ||
   1192 	 (*line == '?') ||
   1193 	 (*line == ':') ||
   1194 	 (*line == '!')) &&
   1195 	(line[1] != '='))
   1196     {
   1197 	return (FALSE);
   1198     } else {
   1199 	return (haveName);
   1200     }
   1201 }
   1202 
   1203 /*-
   1204  *---------------------------------------------------------------------
   1205  * Parse_DoVar  --
   1206  *	Take the variable assignment in the passed line and do it in the
   1207  *	global context.
   1208  *
   1209  *	Note: There is a lexical ambiguity with assignment modifier characters
   1210  *	in variable names. This routine interprets the character before the =
   1211  *	as a modifier. Therefore, an assignment like
   1212  *	    C++=/usr/bin/CC
   1213  *	is interpreted as "C+ +=" instead of "C++ =".
   1214  *
   1215  * Results:
   1216  *	none
   1217  *
   1218  * Side Effects:
   1219  *	the variable structure of the given variable name is altered in the
   1220  *	global context.
   1221  *---------------------------------------------------------------------
   1222  */
   1223 void
   1224 Parse_DoVar (line, ctxt)
   1225     char            *line;	/* a line guaranteed to be a variable
   1226 				 * assignment. This reduces error checks */
   1227     GNode   	    *ctxt;    	/* Context in which to do the assignment */
   1228 {
   1229     char	   *cp;	/* pointer into line */
   1230     enum {
   1231 	VAR_SUBST, VAR_APPEND, VAR_SHELL, VAR_NORMAL
   1232     }	    	    type;   	/* Type of assignment */
   1233     char            *opc;	/* ptr to operator character to
   1234 				 * null-terminate the variable name */
   1235     /*
   1236      * Avoid clobbered variable warnings by forcing the compiler
   1237      * to ``unregister'' variables
   1238      */
   1239 #if __GNUC__
   1240     (void) &cp;
   1241     (void) &line;
   1242 #endif
   1243 
   1244     /*
   1245      * Skip to variable name
   1246      */
   1247     while ((*line == ' ') || (*line == '\t')) {
   1248 	line++;
   1249     }
   1250 
   1251     /*
   1252      * Skip to operator character, nulling out whitespace as we go
   1253      */
   1254     for (cp = line + 1; *cp != '='; cp++) {
   1255 	if (isspace (*cp)) {
   1256 	    *cp = '\0';
   1257 	}
   1258     }
   1259     opc = cp-1;		/* operator is the previous character */
   1260     *cp++ = '\0';	/* nuke the = */
   1261 
   1262     /*
   1263      * Check operator type
   1264      */
   1265     switch (*opc) {
   1266 	case '+':
   1267 	    type = VAR_APPEND;
   1268 	    *opc = '\0';
   1269 	    break;
   1270 
   1271 	case '?':
   1272 	    /*
   1273 	     * If the variable already has a value, we don't do anything.
   1274 	     */
   1275 	    *opc = '\0';
   1276 	    if (Var_Exists(line, ctxt)) {
   1277 		return;
   1278 	    } else {
   1279 		type = VAR_NORMAL;
   1280 	    }
   1281 	    break;
   1282 
   1283 	case ':':
   1284 	    type = VAR_SUBST;
   1285 	    *opc = '\0';
   1286 	    break;
   1287 
   1288 	case '!':
   1289 	    type = VAR_SHELL;
   1290 	    *opc = '\0';
   1291 	    break;
   1292 
   1293 	default:
   1294 	    type = VAR_NORMAL;
   1295 	    break;
   1296     }
   1297 
   1298     while (isspace (*cp)) {
   1299 	cp++;
   1300     }
   1301 
   1302     if (type == VAR_APPEND) {
   1303 	Var_Append (line, cp, ctxt);
   1304     } else if (type == VAR_SUBST) {
   1305 	/*
   1306 	 * Allow variables in the old value to be undefined, but leave their
   1307 	 * invocation alone -- this is done by forcing oldVars to be false.
   1308 	 * XXX: This can cause recursive variables, but that's not hard to do,
   1309 	 * and this allows someone to do something like
   1310 	 *
   1311 	 *  CFLAGS = $(.INCLUDES)
   1312 	 *  CFLAGS := -I.. $(CFLAGS)
   1313 	 *
   1314 	 * And not get an error.
   1315 	 */
   1316 	Boolean	  oldOldVars = oldVars;
   1317 
   1318 	oldVars = FALSE;
   1319 	cp = Var_Subst(NULL, cp, ctxt, FALSE);
   1320 	oldVars = oldOldVars;
   1321 
   1322 	Var_Set(line, cp, ctxt);
   1323 	free(cp);
   1324     } else if (type == VAR_SHELL) {
   1325 	char	*args[4];   	/* Args for invoking the shell */
   1326 	int 	fds[2];	    	/* Pipe streams */
   1327 	int 	cpid;	    	/* Child PID */
   1328 	int 	pid;	    	/* PID from wait() */
   1329 	Boolean	freeCmd;    	/* TRUE if the command needs to be freed, i.e.
   1330 				 * if any variable expansion was performed */
   1331 
   1332 	/*
   1333 	 * Avoid clobbered variable warnings by forcing the compiler
   1334 	 * to ``unregister'' variables
   1335 	 */
   1336 #if __GNUC__
   1337 	(void) &freeCmd;
   1338 #endif
   1339 
   1340 	/*
   1341 	 * Set up arguments for shell
   1342 	 */
   1343 	args[0] = "sh";
   1344 	args[1] = "-c";
   1345 	if (strchr(cp, '$') != (char *)NULL) {
   1346 	    /*
   1347 	     * There's a dollar sign in the command, so perform variable
   1348 	     * expansion on the whole thing. The resulting string will need
   1349 	     * freeing when we're done, so set freeCmd to TRUE.
   1350 	     */
   1351 	    args[2] = Var_Subst(NULL, cp, VAR_CMD, TRUE);
   1352 	    freeCmd = TRUE;
   1353 	} else {
   1354 	    args[2] = cp;
   1355 	    freeCmd = FALSE;
   1356 	}
   1357 	args[3] = (char *)NULL;
   1358 
   1359 	/*
   1360 	 * Open a pipe for fetching its output
   1361 	 */
   1362 	pipe(fds);
   1363 
   1364 	/*
   1365 	 * Fork
   1366 	 */
   1367 	cpid = vfork();
   1368 	if (cpid == 0) {
   1369 	    /*
   1370 	     * Close input side of pipe
   1371 	     */
   1372 	    close(fds[0]);
   1373 
   1374 	    /*
   1375 	     * Duplicate the output stream to the shell's output, then
   1376 	     * shut the extra thing down. Note we don't fetch the error
   1377 	     * stream...why not? Why?
   1378 	     */
   1379 	    dup2(fds[1], 1);
   1380 	    close(fds[1]);
   1381 
   1382 	    execv("/bin/sh", args);
   1383 	    _exit(1);
   1384 	} else if (cpid < 0) {
   1385 	    /*
   1386 	     * Couldn't fork -- tell the user and make the variable null
   1387 	     */
   1388 	    Parse_Error(PARSE_WARNING, "Couldn't exec \"%s\"", cp);
   1389 	    Var_Set(line, "", ctxt);
   1390 	} else {
   1391 	    int	status;
   1392 	    int cc;
   1393 	    Buffer buf;
   1394 	    char *res;
   1395 
   1396 	    /*
   1397 	     * No need for the writing half
   1398 	     */
   1399 	    close(fds[1]);
   1400 
   1401 	    buf = Buf_Init (MAKE_BSIZE);
   1402 
   1403 	    do {
   1404 		char   result[BUFSIZ];
   1405 		cc = read(fds[0], result, sizeof(result));
   1406 		if (cc > 0)
   1407 		    Buf_AddBytes(buf, cc, (unsigned char *) result);
   1408 	    }
   1409 	    while (cc > 0 || (cc == -1 && errno == EINTR));
   1410 
   1411 	    /*
   1412 	     * Close the input side of the pipe.
   1413 	     */
   1414 	    close(fds[0]);
   1415 
   1416 	    /*
   1417 	     * Wait for the process to exit.
   1418 	     */
   1419 	    while(((pid = wait(&status)) != cpid) && (pid >= 0))
   1420 		continue;
   1421 
   1422 	    res = (char *)Buf_GetAll (buf, &cc);
   1423 	    Buf_Destroy (buf, FALSE);
   1424 
   1425 	    if (cc == 0) {
   1426 		/*
   1427 		 * Couldn't read the child's output -- tell the user and
   1428 		 * set the variable to null
   1429 		 */
   1430 		Parse_Error(PARSE_WARNING, "Couldn't read shell's output");
   1431 	    }
   1432 
   1433 	    if (status) {
   1434 		/*
   1435 		 * Child returned an error -- tell the user but still use
   1436 		 * the result.
   1437 		 */
   1438 		Parse_Error(PARSE_WARNING, "\"%s\" returned non-zero", cp);
   1439 	    }
   1440 
   1441 	    /*
   1442 	     * Null-terminate the result, convert newlines to spaces and
   1443 	     * install it in the variable.
   1444 	     */
   1445 	    res[cc] = '\0';
   1446 	    cp = &res[cc] - 1;
   1447 
   1448 	    if (*cp == '\n') {
   1449 		/*
   1450 		 * A final newline is just stripped
   1451 		 */
   1452 		*cp-- = '\0';
   1453 	    }
   1454 	    while (cp >= res) {
   1455 		if (*cp == '\n') {
   1456 		    *cp = ' ';
   1457 		}
   1458 		cp--;
   1459 	    }
   1460 	    Var_Set(line, res, ctxt);
   1461 	    free(res);
   1462 
   1463 	}
   1464 	if (freeCmd) {
   1465 	    free(args[2]);
   1466 	}
   1467     } else {
   1468 	/*
   1469 	 * Normal assignment -- just do it.
   1470 	 */
   1471 	Var_Set (line, cp, ctxt);
   1472     }
   1473 }
   1474 
   1475 /*-
   1476  * ParseAddCmd  --
   1477  *	Lst_ForEach function to add a command line to all targets
   1478  *
   1479  * Results:
   1480  *	Always 0
   1481  *
   1482  * Side Effects:
   1483  *	A new element is added to the commands list of the node.
   1484  */
   1485 static int
   1486 ParseAddCmd(gn, cmd)
   1487 	GNode *gn;	/* the node to which the command is to be added */
   1488 	char *cmd;	/* the command to add */
   1489 {
   1490 	/* if target already supplied, ignore commands */
   1491 	if (!(gn->type & OP_HAS_COMMANDS))
   1492 		(void)Lst_AtEnd(gn->commands, (ClientData)cmd);
   1493 	return(0);
   1494 }
   1495 
   1496 /*-
   1497  *-----------------------------------------------------------------------
   1498  * ParseHasCommands --
   1499  *	Callback procedure for Parse_File when destroying the list of
   1500  *	targets on the last dependency line. Marks a target as already
   1501  *	having commands if it does, to keep from having shell commands
   1502  *	on multiple dependency lines.
   1503  *
   1504  * Results:
   1505  *	Always 0.
   1506  *
   1507  * Side Effects:
   1508  *	OP_HAS_COMMANDS may be set for the target.
   1509  *
   1510  *-----------------------------------------------------------------------
   1511  */
   1512 static int
   1513 ParseHasCommands(gn)
   1514     GNode   	  *gn;	    /* Node to examine */
   1515 {
   1516     if (!Lst_IsEmpty(gn->commands)) {
   1517 	gn->type |= OP_HAS_COMMANDS;
   1518     }
   1519     return(0);
   1520 }
   1521 
   1522 /*-
   1523  *-----------------------------------------------------------------------
   1524  * Parse_AddIncludeDir --
   1525  *	Add a directory to the path searched for included makefiles
   1526  *	bracketed by double-quotes. Used by functions in main.c
   1527  *
   1528  * Results:
   1529  *	None.
   1530  *
   1531  * Side Effects:
   1532  *	The directory is appended to the list.
   1533  *
   1534  *-----------------------------------------------------------------------
   1535  */
   1536 void
   1537 Parse_AddIncludeDir (dir)
   1538     char    	  *dir;	    /* The name of the directory to add */
   1539 {
   1540     Dir_AddDir (parseIncPath, dir);
   1541 }
   1542 
   1543 /*-
   1544  *---------------------------------------------------------------------
   1545  * ParseDoInclude  --
   1546  *	Push to another file.
   1547  *
   1548  *	The input is the line minus the #include. A file spec is a string
   1549  *	enclosed in <> or "". The former is looked for only in sysIncPath.
   1550  *	The latter in . and the directories specified by -I command line
   1551  *	options
   1552  *
   1553  * Results:
   1554  *	None
   1555  *
   1556  * Side Effects:
   1557  *	A structure is added to the includes Lst and readProc, lineno,
   1558  *	fname and curFILE are altered for the new file
   1559  *---------------------------------------------------------------------
   1560  */
   1561 static void
   1562 ParseDoInclude (file)
   1563     char          *file;	/* file specification */
   1564 {
   1565     char          *fullname;	/* full pathname of file */
   1566     IFile         *oldFile;	/* state associated with current file */
   1567     char          endc;	    	/* the character which ends the file spec */
   1568     char          *cp;		/* current position in file spec */
   1569     Boolean 	  isSystem; 	/* TRUE if makefile is a system makefile */
   1570 
   1571     /*
   1572      * Skip to delimiter character so we know where to look
   1573      */
   1574     while ((*file == ' ') || (*file == '\t')) {
   1575 	file++;
   1576     }
   1577 
   1578     if ((*file != '"') && (*file != '<')) {
   1579 	Parse_Error (PARSE_FATAL,
   1580 	    ".include filename must be delimited by '\"' or '<'");
   1581 	return;
   1582     }
   1583 
   1584     /*
   1585      * Set the search path on which to find the include file based on the
   1586      * characters which bracket its name. Angle-brackets imply it's
   1587      * a system Makefile while double-quotes imply it's a user makefile
   1588      */
   1589     if (*file == '<') {
   1590 	isSystem = TRUE;
   1591 	endc = '>';
   1592     } else {
   1593 	isSystem = FALSE;
   1594 	endc = '"';
   1595     }
   1596 
   1597     /*
   1598      * Skip to matching delimiter
   1599      */
   1600     for (cp = ++file; *cp && *cp != endc; cp++) {
   1601 	continue;
   1602     }
   1603 
   1604     if (*cp != endc) {
   1605 	Parse_Error (PARSE_FATAL,
   1606 		     "Unclosed %cinclude filename. '%c' expected",
   1607 		     '.', endc);
   1608 	return;
   1609     }
   1610     *cp = '\0';
   1611 
   1612     /*
   1613      * Substitute for any variables in the file name before trying to
   1614      * find the thing.
   1615      */
   1616     file = Var_Subst (NULL, file, VAR_CMD, FALSE);
   1617 
   1618     /*
   1619      * Now we know the file's name and its search path, we attempt to
   1620      * find the durn thing. A return of NULL indicates the file don't
   1621      * exist.
   1622      */
   1623     if (!isSystem) {
   1624 	/*
   1625 	 * Include files contained in double-quotes are first searched for
   1626 	 * relative to the including file's location. We don't want to
   1627 	 * cd there, of course, so we just tack on the old file's
   1628 	 * leading path components and call Dir_FindFile to see if
   1629 	 * we can locate the beast.
   1630 	 */
   1631 	char	  *prefEnd;
   1632 
   1633 	prefEnd = strrchr (fname, '/');
   1634 	if (prefEnd != (char *)NULL) {
   1635 	    char  	*newName;
   1636 
   1637 	    *prefEnd = '\0';
   1638 	    newName = str_concat (fname, file, STR_ADDSLASH);
   1639 	    fullname = Dir_FindFile (newName, parseIncPath);
   1640 	    if (fullname == (char *)NULL) {
   1641 		fullname = Dir_FindFile(newName, dirSearchPath);
   1642 	    }
   1643 	    free (newName);
   1644 	    *prefEnd = '/';
   1645 	} else {
   1646 	    fullname = (char *)NULL;
   1647 	}
   1648     } else {
   1649 	fullname = (char *)NULL;
   1650     }
   1651 
   1652     if (fullname == (char *)NULL) {
   1653 	/*
   1654 	 * System makefile or makefile wasn't found in same directory as
   1655 	 * included makefile. Search for it first on the -I search path,
   1656 	 * then on the .PATH search path, if not found in a -I directory.
   1657 	 * XXX: Suffix specific?
   1658 	 */
   1659 	fullname = Dir_FindFile (file, parseIncPath);
   1660 	if (fullname == (char *)NULL) {
   1661 	    fullname = Dir_FindFile(file, dirSearchPath);
   1662 	}
   1663     }
   1664 
   1665     if (fullname == (char *)NULL) {
   1666 	/*
   1667 	 * Still haven't found the makefile. Look for it on the system
   1668 	 * path as a last resort.
   1669 	 */
   1670 	fullname = Dir_FindFile(file, sysIncPath);
   1671     }
   1672 
   1673     if (fullname == (char *) NULL) {
   1674 	*cp = endc;
   1675 	Parse_Error (PARSE_FATAL, "Could not find %s", file);
   1676 	return;
   1677     }
   1678 
   1679     /*
   1680      * Once we find the absolute path to the file, we get to save all the
   1681      * state from the current file before we can start reading this
   1682      * include file. The state is stored in an IFile structure which
   1683      * is placed on a list with other IFile structures. The list makes
   1684      * a very nice stack to track how we got here...
   1685      */
   1686     oldFile = (IFile *) emalloc (sizeof (IFile));
   1687     oldFile->fname = fname;
   1688 
   1689     oldFile->F = curFILE;
   1690     oldFile->p = curPTR;
   1691     oldFile->lineno = lineno;
   1692 
   1693     (void) Lst_AtFront (includes, (ClientData)oldFile);
   1694 
   1695     /*
   1696      * Once the previous state has been saved, we can get down to reading
   1697      * the new file. We set up the name of the file to be the absolute
   1698      * name of the include file so error messages refer to the right
   1699      * place. Naturally enough, we start reading at line number 0.
   1700      */
   1701     fname = fullname;
   1702     lineno = 0;
   1703 
   1704     curFILE = fopen (fullname, "r");
   1705     curPTR = NULL;
   1706     if (curFILE == (FILE * ) NULL) {
   1707 	Parse_Error (PARSE_FATAL, "Cannot open %s", fullname);
   1708 	/*
   1709 	 * Pop to previous file
   1710 	 */
   1711 	(void) ParseEOF(0);
   1712     }
   1713 }
   1714 
   1715 
   1716 /*-
   1717  *---------------------------------------------------------------------
   1718  * Parse_FromString  --
   1719  *	Start Parsing from the given string
   1720  *
   1721  * Results:
   1722  *	None
   1723  *
   1724  * Side Effects:
   1725  *	A structure is added to the includes Lst and readProc, lineno,
   1726  *	fname and curFILE are altered for the new file
   1727  *---------------------------------------------------------------------
   1728  */
   1729 void
   1730 Parse_FromString(str)
   1731     char *str;
   1732 {
   1733     IFile         *oldFile;	/* state associated with this file */
   1734 
   1735     if (DEBUG(FOR))
   1736 	(void) fprintf(stderr, "%s\n----\n", str);
   1737 
   1738     oldFile = (IFile *) emalloc (sizeof (IFile));
   1739     oldFile->lineno = lineno;
   1740     oldFile->fname = fname;
   1741     oldFile->F = curFILE;
   1742     oldFile->p = curPTR;
   1743 
   1744     (void) Lst_AtFront (includes, (ClientData)oldFile);
   1745 
   1746     curFILE = NULL;
   1747     curPTR = (PTR *) emalloc (sizeof (PTR));
   1748     curPTR->str = curPTR->ptr = str;
   1749     lineno = 0;
   1750     fname = strdup(fname);
   1751 }
   1752 
   1753 
   1754 #ifdef SYSVINCLUDE
   1755 /*-
   1756  *---------------------------------------------------------------------
   1757  * ParseTraditionalInclude  --
   1758  *	Push to another file.
   1759  *
   1760  *	The input is the line minus the "include".  The file name is
   1761  *	the string following the "include".
   1762  *
   1763  * Results:
   1764  *	None
   1765  *
   1766  * Side Effects:
   1767  *	A structure is added to the includes Lst and readProc, lineno,
   1768  *	fname and curFILE are altered for the new file
   1769  *---------------------------------------------------------------------
   1770  */
   1771 static void
   1772 ParseTraditionalInclude (file)
   1773     char          *file;	/* file specification */
   1774 {
   1775     char          *fullname;	/* full pathname of file */
   1776     IFile         *oldFile;	/* state associated with current file */
   1777     char          *cp;		/* current position in file spec */
   1778     char	  *prefEnd;
   1779 
   1780     /*
   1781      * Skip over whitespace
   1782      */
   1783     while ((*file == ' ') || (*file == '\t')) {
   1784 	file++;
   1785     }
   1786 
   1787     if (*file == '\0') {
   1788 	Parse_Error (PARSE_FATAL,
   1789 		     "Filename missing from \"include\"");
   1790 	return;
   1791     }
   1792 
   1793     /*
   1794      * Skip to end of line or next whitespace
   1795      */
   1796     for (cp = file; *cp && *cp != '\n' && *cp != '\t' && *cp != ' '; cp++) {
   1797 	continue;
   1798     }
   1799 
   1800     *cp = '\0';
   1801 
   1802     /*
   1803      * Substitute for any variables in the file name before trying to
   1804      * find the thing.
   1805      */
   1806     file = Var_Subst (NULL, file, VAR_CMD, FALSE);
   1807 
   1808     /*
   1809      * Now we know the file's name, we attempt to find the durn thing.
   1810      * A return of NULL indicates the file don't exist.
   1811      *
   1812      * Include files are first searched for relative to the including
   1813      * file's location. We don't want to cd there, of course, so we
   1814      * just tack on the old file's leading path components and call
   1815      * Dir_FindFile to see if we can locate the beast.
   1816      * XXX - this *does* search in the current directory, right?
   1817      */
   1818 
   1819     prefEnd = strrchr (fname, '/');
   1820     if (prefEnd != (char *)NULL) {
   1821 	char  	*newName;
   1822 
   1823 	*prefEnd = '\0';
   1824 	newName = str_concat (fname, file, STR_ADDSLASH);
   1825 	fullname = Dir_FindFile (newName, parseIncPath);
   1826 	if (fullname == (char *)NULL) {
   1827 	    fullname = Dir_FindFile(newName, dirSearchPath);
   1828 	}
   1829 	free (newName);
   1830 	*prefEnd = '/';
   1831     } else {
   1832 	fullname = (char *)NULL;
   1833     }
   1834 
   1835     if (fullname == (char *)NULL) {
   1836 	/*
   1837 	 * System makefile or makefile wasn't found in same directory as
   1838 	 * included makefile. Search for it first on the -I search path,
   1839 	 * then on the .PATH search path, if not found in a -I directory.
   1840 	 * XXX: Suffix specific?
   1841 	 */
   1842 	fullname = Dir_FindFile (file, parseIncPath);
   1843 	if (fullname == (char *)NULL) {
   1844 	    fullname = Dir_FindFile(file, dirSearchPath);
   1845 	}
   1846     }
   1847 
   1848     if (fullname == (char *)NULL) {
   1849 	/*
   1850 	 * Still haven't found the makefile. Look for it on the system
   1851 	 * path as a last resort.
   1852 	 */
   1853 	fullname = Dir_FindFile(file, sysIncPath);
   1854     }
   1855 
   1856     if (fullname == (char *) NULL) {
   1857 	Parse_Error (PARSE_FATAL, "Could not find %s", file);
   1858 	return;
   1859     }
   1860 
   1861     /*
   1862      * Once we find the absolute path to the file, we get to save all the
   1863      * state from the current file before we can start reading this
   1864      * include file. The state is stored in an IFile structure which
   1865      * is placed on a list with other IFile structures. The list makes
   1866      * a very nice stack to track how we got here...
   1867      */
   1868     oldFile = (IFile *) emalloc (sizeof (IFile));
   1869     oldFile->fname = fname;
   1870 
   1871     oldFile->F = curFILE;
   1872     oldFile->p = curPTR;
   1873     oldFile->lineno = lineno;
   1874 
   1875     (void) Lst_AtFront (includes, (ClientData)oldFile);
   1876 
   1877     /*
   1878      * Once the previous state has been saved, we can get down to reading
   1879      * the new file. We set up the name of the file to be the absolute
   1880      * name of the include file so error messages refer to the right
   1881      * place. Naturally enough, we start reading at line number 0.
   1882      */
   1883     fname = fullname;
   1884     lineno = 0;
   1885 
   1886     curFILE = fopen (fullname, "r");
   1887     curPTR = NULL;
   1888     if (curFILE == (FILE * ) NULL) {
   1889 	Parse_Error (PARSE_FATAL, "Cannot open %s", fullname);
   1890 	/*
   1891 	 * Pop to previous file
   1892 	 */
   1893 	(void) ParseEOF(1);
   1894     }
   1895 }
   1896 #endif
   1897 
   1898 /*-
   1899  *---------------------------------------------------------------------
   1900  * ParseEOF  --
   1901  *	Called when EOF is reached in the current file. If we were reading
   1902  *	an include file, the includes stack is popped and things set up
   1903  *	to go back to reading the previous file at the previous location.
   1904  *
   1905  * Results:
   1906  *	CONTINUE if there's more to do. DONE if not.
   1907  *
   1908  * Side Effects:
   1909  *	The old curFILE, is closed. The includes list is shortened.
   1910  *	lineno, curFILE, and fname are changed if CONTINUE is returned.
   1911  *---------------------------------------------------------------------
   1912  */
   1913 static int
   1914 ParseEOF (opened)
   1915     int opened;
   1916 {
   1917     IFile     *ifile;	/* the state on the top of the includes stack */
   1918 
   1919     if (Lst_IsEmpty (includes)) {
   1920 	return (DONE);
   1921     }
   1922 
   1923     ifile = (IFile *) Lst_DeQueue (includes);
   1924     free ((Address) fname);
   1925     fname = ifile->fname;
   1926     lineno = ifile->lineno;
   1927     if (opened && curFILE)
   1928 	(void) fclose (curFILE);
   1929     if (curPTR) {
   1930 	free((Address) curPTR->str);
   1931 	free((Address) curPTR);
   1932     }
   1933     curFILE = ifile->F;
   1934     curPTR = ifile->p;
   1935     free ((Address)ifile);
   1936     return (CONTINUE);
   1937 }
   1938 
   1939 /*-
   1940  *---------------------------------------------------------------------
   1941  * ParseReadc  --
   1942  *	Read a character from the current file
   1943  *
   1944  * Results:
   1945  *	The character that was read
   1946  *
   1947  * Side Effects:
   1948  *---------------------------------------------------------------------
   1949  */
   1950 static int
   1951 ParseReadc()
   1952 {
   1953     if (curFILE)
   1954 	return fgetc(curFILE);
   1955 
   1956     if (curPTR && *curPTR->ptr)
   1957 	return *curPTR->ptr++;
   1958     return EOF;
   1959 }
   1960 
   1961 
   1962 /*-
   1963  *---------------------------------------------------------------------
   1964  * ParseUnreadc  --
   1965  *	Put back a character to the current file
   1966  *
   1967  * Results:
   1968  *	None.
   1969  *
   1970  * Side Effects:
   1971  *---------------------------------------------------------------------
   1972  */
   1973 static void
   1974 ParseUnreadc(c)
   1975     int c;
   1976 {
   1977     if (curFILE) {
   1978 	ungetc(c, curFILE);
   1979 	return;
   1980     }
   1981     if (curPTR) {
   1982 	*--(curPTR->ptr) = c;
   1983 	return;
   1984     }
   1985 }
   1986 
   1987 
   1988 /* ParseSkipLine():
   1989  *	Grab the next line
   1990  */
   1991 static char *
   1992 ParseSkipLine(skip)
   1993     int skip; 		/* Skip lines that don't start with . */
   1994 {
   1995     char *line;
   1996     int c, lastc = '\0', lineLength;
   1997     Buffer buf;
   1998 
   1999     c = ParseReadc();
   2000 
   2001     if (skip) {
   2002 	/*
   2003 	 * Skip lines until get to one that begins with a
   2004 	 * special char.
   2005 	 */
   2006 	while ((c != '.') && (c != EOF)) {
   2007 	    while (((c != '\n') || (lastc == '\\')) && (c != EOF))
   2008 	    {
   2009 		/*
   2010 		 * Advance to next unescaped newline
   2011 		 */
   2012 		if ((lastc = c) == '\n') {
   2013 		    lineno++;
   2014 		}
   2015 		c = ParseReadc();
   2016 	    }
   2017 	    lineno++;
   2018 
   2019 	    lastc = c;
   2020 	    c = ParseReadc ();
   2021 	}
   2022     }
   2023 
   2024     if (c == EOF) {
   2025 	Parse_Error (PARSE_FATAL, "Unclosed conditional/for loop");
   2026 	return ((char *)NULL);
   2027     }
   2028 
   2029     /*
   2030      * Read the entire line into buf
   2031      */
   2032     buf = Buf_Init (MAKE_BSIZE);
   2033     if (c != '\n') {
   2034 	do {
   2035 	    Buf_AddByte (buf, (Byte)c);
   2036 	    c = ParseReadc();
   2037 	} while ((c != '\n') && (c != EOF));
   2038     }
   2039     lineno++;
   2040 
   2041     Buf_AddByte (buf, (Byte)'\0');
   2042     line = (char *)Buf_GetAll (buf, &lineLength);
   2043     Buf_Destroy (buf, FALSE);
   2044     return line;
   2045 }
   2046 
   2047 
   2048 /*-
   2049  *---------------------------------------------------------------------
   2050  * ParseReadLine --
   2051  *	Read an entire line from the input file. Called only by Parse_File.
   2052  *	To facilitate escaped newlines and what have you, a character is
   2053  *	buffered in 'lastc', which is '\0' when no characters have been
   2054  *	read. When we break out of the loop, c holds the terminating
   2055  *	character and lastc holds a character that should be added to
   2056  *	the line (unless we don't read anything but a terminator).
   2057  *
   2058  * Results:
   2059  *	A line w/o its newline
   2060  *
   2061  * Side Effects:
   2062  *	Only those associated with reading a character
   2063  *---------------------------------------------------------------------
   2064  */
   2065 static char *
   2066 ParseReadLine ()
   2067 {
   2068     Buffer  	  buf;	    	/* Buffer for current line */
   2069     register int  c;	      	/* the current character */
   2070     register int  lastc;    	/* The most-recent character */
   2071     Boolean	  semiNL;     	/* treat semi-colons as newlines */
   2072     Boolean	  ignDepOp;   	/* TRUE if should ignore dependency operators
   2073 				 * for the purposes of setting semiNL */
   2074     Boolean 	  ignComment;	/* TRUE if should ignore comments (in a
   2075 				 * shell command */
   2076     char    	  *line;    	/* Result */
   2077     int	    	  lineLength;	/* Length of result */
   2078 
   2079     semiNL = FALSE;
   2080     ignDepOp = FALSE;
   2081     ignComment = FALSE;
   2082 
   2083     /*
   2084      * Handle special-characters at the beginning of the line. Either a
   2085      * leading tab (shell command) or pound-sign (possible conditional)
   2086      * forces us to ignore comments and dependency operators and treat
   2087      * semi-colons as semi-colons (by leaving semiNL FALSE). This also
   2088      * discards completely blank lines.
   2089      */
   2090     for (;;) {
   2091 	c = ParseReadc();
   2092 
   2093 	if (c == '\t') {
   2094 	    ignComment = ignDepOp = TRUE;
   2095 	    break;
   2096 	} else if (c == '\n') {
   2097 	    lineno++;
   2098 	} else if (c == '#') {
   2099 	    ParseUnreadc(c);
   2100 	    break;
   2101 	} else {
   2102 	    /*
   2103 	     * Anything else breaks out without doing anything
   2104 	     */
   2105 	    break;
   2106 	}
   2107     }
   2108 
   2109     if (c != EOF) {
   2110 	lastc = c;
   2111 	buf = Buf_Init(MAKE_BSIZE);
   2112 
   2113 	while (((c = ParseReadc ()) != '\n' || (lastc == '\\')) &&
   2114 	       (c != EOF))
   2115 	{
   2116 test_char:
   2117 	    switch(c) {
   2118 	    case '\n':
   2119 		/*
   2120 		 * Escaped newline: read characters until a non-space or an
   2121 		 * unescaped newline and replace them all by a single space.
   2122 		 * This is done by storing the space over the backslash and
   2123 		 * dropping through with the next nonspace. If it is a
   2124 		 * semi-colon and semiNL is TRUE, it will be recognized as a
   2125 		 * newline in the code below this...
   2126 		 */
   2127 		lineno++;
   2128 		lastc = ' ';
   2129 		while ((c = ParseReadc ()) == ' ' || c == '\t') {
   2130 		    continue;
   2131 		}
   2132 		if (c == EOF || c == '\n') {
   2133 		    goto line_read;
   2134 		} else {
   2135 		    /*
   2136 		     * Check for comments, semiNL's, etc. -- easier than
   2137 		     * ParseUnreadc(c); continue;
   2138 		     */
   2139 		    goto test_char;
   2140 		}
   2141 		/*NOTREACHED*/
   2142 		break;
   2143 
   2144 	    case ';':
   2145 		/*
   2146 		 * Semi-colon: Need to see if it should be interpreted as a
   2147 		 * newline
   2148 		 */
   2149 		if (semiNL) {
   2150 		    /*
   2151 		     * To make sure the command that may be following this
   2152 		     * semi-colon begins with a tab, we push one back into the
   2153 		     * input stream. This will overwrite the semi-colon in the
   2154 		     * buffer. If there is no command following, this does no
   2155 		     * harm, since the newline remains in the buffer and the
   2156 		     * whole line is ignored.
   2157 		     */
   2158 		    ParseUnreadc('\t');
   2159 		    goto line_read;
   2160 		}
   2161 		break;
   2162 	    case '=':
   2163 		if (!semiNL) {
   2164 		    /*
   2165 		     * Haven't seen a dependency operator before this, so this
   2166 		     * must be a variable assignment -- don't pay attention to
   2167 		     * dependency operators after this.
   2168 		     */
   2169 		    ignDepOp = TRUE;
   2170 		} else if (lastc == ':' || lastc == '!') {
   2171 		    /*
   2172 		     * Well, we've seen a dependency operator already, but it
   2173 		     * was the previous character, so this is really just an
   2174 		     * expanded variable assignment. Revert semi-colons to
   2175 		     * being just semi-colons again and ignore any more
   2176 		     * dependency operators.
   2177 		     *
   2178 		     * XXX: Note that a line like "foo : a:=b" will blow up,
   2179 		     * but who'd write a line like that anyway?
   2180 		     */
   2181 		    ignDepOp = TRUE; semiNL = FALSE;
   2182 		}
   2183 		break;
   2184 	    case '#':
   2185 		if (!ignComment) {
   2186 		    if (compatMake || (lastc != '\\')) {
   2187 			/*
   2188 			 * If the character is a hash mark and it isn't escaped
   2189 			 * (or we're being compatible), the thing is a comment.
   2190 			 * Skip to the end of the line.
   2191 			 */
   2192 			do {
   2193 			    c = ParseReadc();
   2194 			} while ((c != '\n') && (c != EOF));
   2195 			goto line_read;
   2196 		    } else {
   2197 			/*
   2198 			 * Don't add the backslash. Just let the # get copied
   2199 			 * over.
   2200 			 */
   2201 			lastc = c;
   2202 			continue;
   2203 		    }
   2204 		}
   2205 		break;
   2206 	    case ':':
   2207 	    case '!':
   2208 		if (!ignDepOp && (c == ':' || c == '!')) {
   2209 		    /*
   2210 		     * A semi-colon is recognized as a newline only on
   2211 		     * dependency lines. Dependency lines are lines with a
   2212 		     * colon or an exclamation point. Ergo...
   2213 		     */
   2214 		    semiNL = TRUE;
   2215 		}
   2216 		break;
   2217 	    }
   2218 	    /*
   2219 	     * Copy in the previous character and save this one in lastc.
   2220 	     */
   2221 	    Buf_AddByte (buf, (Byte)lastc);
   2222 	    lastc = c;
   2223 
   2224 	}
   2225     line_read:
   2226 	lineno++;
   2227 
   2228 	if (lastc != '\0') {
   2229 	    Buf_AddByte (buf, (Byte)lastc);
   2230 	}
   2231 	Buf_AddByte (buf, (Byte)'\0');
   2232 	line = (char *)Buf_GetAll (buf, &lineLength);
   2233 	Buf_Destroy (buf, FALSE);
   2234 
   2235 	if (line[0] == '.') {
   2236 	    /*
   2237 	     * The line might be a conditional. Ask the conditional module
   2238 	     * about it and act accordingly
   2239 	     */
   2240 	    switch (Cond_Eval (line)) {
   2241 	    case COND_SKIP:
   2242 		/*
   2243 		 * Skip to next conditional that evaluates to COND_PARSE.
   2244 		 */
   2245 		do {
   2246 		    free (line);
   2247 		    line = ParseSkipLine(1);
   2248 		} while (line && Cond_Eval(line) != COND_PARSE);
   2249 		if (line == NULL)
   2250 		    break;
   2251 		/*FALLTHRU*/
   2252 	    case COND_PARSE:
   2253 		free ((Address) line);
   2254 		line = ParseReadLine();
   2255 		break;
   2256 	    case COND_INVALID:
   2257 		if (For_Eval(line)) {
   2258 		    int ok;
   2259 		    free(line);
   2260 		    do {
   2261 			/*
   2262 			 * Skip after the matching end
   2263 			 */
   2264 			line = ParseSkipLine(0);
   2265 			if (line == NULL) {
   2266 			    Parse_Error (PARSE_FATAL,
   2267 				     "Unexpected end of file in for loop.\n");
   2268 			    break;
   2269 			}
   2270 			ok = For_Eval(line);
   2271 			free(line);
   2272 		    }
   2273 		    while (ok);
   2274 		    if (line != NULL)
   2275 			For_Run();
   2276 		    line = ParseReadLine();
   2277 		}
   2278 		break;
   2279 	    }
   2280 	}
   2281 	return (line);
   2282 
   2283     } else {
   2284 	/*
   2285 	 * Hit end-of-file, so return a NULL line to indicate this.
   2286 	 */
   2287 	return((char *)NULL);
   2288     }
   2289 }
   2290 
   2291 /*-
   2292  *-----------------------------------------------------------------------
   2293  * ParseFinishLine --
   2294  *	Handle the end of a dependency group.
   2295  *
   2296  * Results:
   2297  *	Nothing.
   2298  *
   2299  * Side Effects:
   2300  *	inLine set FALSE. 'targets' list destroyed.
   2301  *
   2302  *-----------------------------------------------------------------------
   2303  */
   2304 static void
   2305 ParseFinishLine()
   2306 {
   2307     extern int Suff_EndTransform();
   2308 
   2309     if (inLine) {
   2310 	Lst_ForEach(targets, Suff_EndTransform, (ClientData)NULL);
   2311 	Lst_Destroy (targets, ParseHasCommands);
   2312 	inLine = FALSE;
   2313     }
   2314 }
   2315 
   2316 
   2317 /*-
   2318  *---------------------------------------------------------------------
   2319  * Parse_File --
   2320  *	Parse a file into its component parts, incorporating it into the
   2321  *	current dependency graph. This is the main function and controls
   2322  *	almost every other function in this module
   2323  *
   2324  * Results:
   2325  *	None
   2326  *
   2327  * Side Effects:
   2328  *	Loads. Nodes are added to the list of all targets, nodes and links
   2329  *	are added to the dependency graph. etc. etc. etc.
   2330  *---------------------------------------------------------------------
   2331  */
   2332 void
   2333 Parse_File(name, stream)
   2334     char          *name;	/* the name of the file being read */
   2335     FILE *	  stream;   	/* Stream open to makefile to parse */
   2336 {
   2337     register char *cp,		/* pointer into the line */
   2338                   *line;	/* the line we're working on */
   2339 
   2340     inLine = FALSE;
   2341     fname = name;
   2342     curFILE = stream;
   2343     lineno = 0;
   2344     fatals = 0;
   2345 
   2346     do {
   2347 	while ((line = ParseReadLine ()) != NULL) {
   2348 	    if (*line == '.') {
   2349 		/*
   2350 		 * Lines that begin with the special character are either
   2351 		 * include or undef directives.
   2352 		 */
   2353 		for (cp = line + 1; isspace (*cp); cp++) {
   2354 		    continue;
   2355 		}
   2356 		if (strncmp (cp, "include", 7) == 0) {
   2357 		    ParseDoInclude (cp + 7);
   2358 		    goto nextLine;
   2359 		} else if (strncmp(cp, "undef", 5) == 0) {
   2360 		    char *cp2;
   2361 		    for (cp += 5; isspace(*cp); cp++) {
   2362 			continue;
   2363 		    }
   2364 
   2365 		    for (cp2 = cp; !isspace(*cp2) && (*cp2 != '\0'); cp2++) {
   2366 			continue;
   2367 		    }
   2368 
   2369 		    *cp2 = '\0';
   2370 
   2371 		    Var_Delete(cp, VAR_GLOBAL);
   2372 		    goto nextLine;
   2373 		}
   2374 	    }
   2375 	    if (*line == '#') {
   2376 		/* If we're this far, the line must be a comment. */
   2377 		goto nextLine;
   2378 	    }
   2379 
   2380 	    if (*line == '\t') {
   2381 		/*
   2382 		 * If a line starts with a tab, it can only hope to be
   2383 		 * a creation command.
   2384 		 */
   2385 #ifndef POSIX
   2386 	    shellCommand:
   2387 #endif
   2388 		for (cp = line + 1; isspace (*cp); cp++) {
   2389 		    continue;
   2390 		}
   2391 		if (*cp) {
   2392 		    if (inLine) {
   2393 			/*
   2394 			 * So long as it's not a blank line and we're actually
   2395 			 * in a dependency spec, add the command to the list of
   2396 			 * commands of all targets in the dependency spec
   2397 			 */
   2398 			Lst_ForEach (targets, ParseAddCmd, (ClientData)cp);
   2399 			continue;
   2400 		    } else {
   2401 			Parse_Error (PARSE_FATAL,
   2402 				     "Unassociated shell command \"%.20s\"",
   2403 				     cp);
   2404 		    }
   2405 		}
   2406 #ifdef SYSVINCLUDE
   2407 	    } else if (strncmp (line, "include", 7) == 0 &&
   2408 		       strchr(line, ':') == NULL) {
   2409 		/*
   2410 		 * It's an S3/S5-style "include".
   2411 		 */
   2412 		ParseTraditionalInclude (line + 7);
   2413 		goto nextLine;
   2414 #endif
   2415 	    } else if (Parse_IsVar (line)) {
   2416 		ParseFinishLine();
   2417 		Parse_DoVar (line, VAR_GLOBAL);
   2418 	    } else {
   2419 		/*
   2420 		 * We now know it's a dependency line so it needs to have all
   2421 		 * variables expanded before being parsed. Tell the variable
   2422 		 * module to complain if some variable is undefined...
   2423 		 * To make life easier on novices, if the line is indented we
   2424 		 * first make sure the line has a dependency operator in it.
   2425 		 * If it doesn't have an operator and we're in a dependency
   2426 		 * line's script, we assume it's actually a shell command
   2427 		 * and add it to the current list of targets.
   2428 		 *
   2429 		 * Note that POSIX declares all lines that start with
   2430 		 * whitespace are shell commands, so there's no need to check
   2431 		 * here...
   2432 		 */
   2433 #ifndef POSIX
   2434 		Boolean	nonSpace = FALSE;
   2435 #endif
   2436 
   2437 		cp = line;
   2438 #ifndef POSIX
   2439 		if (line[0] == ' ') {
   2440 		    while ((*cp != ':') && (*cp != '!') && (*cp != '\0')) {
   2441 			if (!isspace(*cp)) {
   2442 			    nonSpace = TRUE;
   2443 			}
   2444 			cp++;
   2445 		    }
   2446 		}
   2447 
   2448 		if (*cp == '\0') {
   2449 		    if (inLine) {
   2450 			Parse_Error (PARSE_WARNING,
   2451 				     "Shell command needs a leading tab");
   2452 			goto shellCommand;
   2453 		    } else if (nonSpace) {
   2454 			Parse_Error (PARSE_FATAL, "Missing operator");
   2455 		    }
   2456 		} else {
   2457 #endif
   2458 		    ParseFinishLine();
   2459 
   2460 		    cp = Var_Subst (NULL, line, VAR_CMD, TRUE);
   2461 		    free (line);
   2462 		    line = cp;
   2463 
   2464 		    /*
   2465 		     * Need a non-circular list for the target nodes
   2466 		     */
   2467 		    targets = Lst_Init (FALSE);
   2468 		    inLine = TRUE;
   2469 
   2470 		    ParseDoDependency (line);
   2471 #ifndef POSIX
   2472 		}
   2473 #endif
   2474 	    }
   2475 
   2476 	    nextLine:
   2477 
   2478 	    free (line);
   2479 	}
   2480 	/*
   2481 	 * Reached EOF, but it may be just EOF of an include file...
   2482 	 */
   2483     } while (ParseEOF(1) == CONTINUE);
   2484 
   2485     /*
   2486      * Make sure conditionals are clean
   2487      */
   2488     Cond_End();
   2489 
   2490     if (fatals) {
   2491 	fprintf (stderr, "Fatal errors encountered -- cannot continue\n");
   2492 	exit (1);
   2493     }
   2494 }
   2495 
   2496 /*-
   2497  *---------------------------------------------------------------------
   2498  * Parse_Init --
   2499  *	initialize the parsing module
   2500  *
   2501  * Results:
   2502  *	none
   2503  *
   2504  * Side Effects:
   2505  *	the parseIncPath list is initialized...
   2506  *---------------------------------------------------------------------
   2507  */
   2508 void
   2509 Parse_Init ()
   2510 {
   2511 	char *cp = NULL, *start;
   2512 					/* avoid faults on read-only strings */
   2513 	static char syspath[] = _PATH_DEFSYSPATH;
   2514 
   2515     mainNode = NILGNODE;
   2516     parseIncPath = Lst_Init (FALSE);
   2517     sysIncPath = Lst_Init (FALSE);
   2518     includes = Lst_Init (FALSE);
   2519 
   2520     /*
   2521      * Add the directories from the DEFSYSPATH (more than one may be given
   2522      * as dir1:...:dirn) to the system include path.
   2523      */
   2524     for (start = syspath; *start != '\0'; start = cp) {
   2525 	for (cp = start; *cp != '\0' && *cp != ':'; cp++)
   2526 	    continue;
   2527 	if (*cp == '\0') {
   2528 	    Dir_AddDir(sysIncPath, start);
   2529 	} else {
   2530 	    *cp++ = '\0';
   2531 	    Dir_AddDir(sysIncPath, start);
   2532 	}
   2533     }
   2534 }
   2535 
   2536 /*-
   2537  *-----------------------------------------------------------------------
   2538  * Parse_MainName --
   2539  *	Return a Lst of the main target to create for main()'s sake. If
   2540  *	no such target exists, we Punt with an obnoxious error message.
   2541  *
   2542  * Results:
   2543  *	A Lst of the single node to create.
   2544  *
   2545  * Side Effects:
   2546  *	None.
   2547  *
   2548  *-----------------------------------------------------------------------
   2549  */
   2550 Lst
   2551 Parse_MainName()
   2552 {
   2553     Lst           main;	/* result list */
   2554 
   2555     main = Lst_Init (FALSE);
   2556 
   2557     if (mainNode == NILGNODE) {
   2558 	Punt ("make: no target to make.\n");
   2559     	/*NOTREACHED*/
   2560     } else if (mainNode->type & OP_DOUBLEDEP) {
   2561 	(void) Lst_AtEnd (main, (ClientData)mainNode);
   2562 	Lst_Concat(main, mainNode->cohorts, LST_CONCNEW);
   2563     }
   2564     else
   2565 	(void) Lst_AtEnd (main, (ClientData)mainNode);
   2566     return (main);
   2567 }
   2568