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var.c revision 1.182
      1 /*	$NetBSD: var.c,v 1.182 2013/07/16 14:00:53 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1988, 1989, 1990, 1993
      5  *	The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 /*
     36  * Copyright (c) 1989 by Berkeley Softworks
     37  * All rights reserved.
     38  *
     39  * This code is derived from software contributed to Berkeley by
     40  * Adam de Boor.
     41  *
     42  * Redistribution and use in source and binary forms, with or without
     43  * modification, are permitted provided that the following conditions
     44  * are met:
     45  * 1. Redistributions of source code must retain the above copyright
     46  *    notice, this list of conditions and the following disclaimer.
     47  * 2. Redistributions in binary form must reproduce the above copyright
     48  *    notice, this list of conditions and the following disclaimer in the
     49  *    documentation and/or other materials provided with the distribution.
     50  * 3. All advertising materials mentioning features or use of this software
     51  *    must display the following acknowledgement:
     52  *	This product includes software developed by the University of
     53  *	California, Berkeley and its contributors.
     54  * 4. Neither the name of the University nor the names of its contributors
     55  *    may be used to endorse or promote products derived from this software
     56  *    without specific prior written permission.
     57  *
     58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     68  * SUCH DAMAGE.
     69  */
     70 
     71 #ifndef MAKE_NATIVE
     72 static char rcsid[] = "$NetBSD: var.c,v 1.182 2013/07/16 14:00:53 christos Exp $";
     73 #else
     74 #include <sys/cdefs.h>
     75 #ifndef lint
     76 #if 0
     77 static char sccsid[] = "@(#)var.c	8.3 (Berkeley) 3/19/94";
     78 #else
     79 __RCSID("$NetBSD: var.c,v 1.182 2013/07/16 14:00:53 christos Exp $");
     80 #endif
     81 #endif /* not lint */
     82 #endif
     83 
     84 /*-
     85  * var.c --
     86  *	Variable-handling functions
     87  *
     88  * Interface:
     89  *	Var_Set		    Set the value of a variable in the given
     90  *			    context. The variable is created if it doesn't
     91  *			    yet exist. The value and variable name need not
     92  *			    be preserved.
     93  *
     94  *	Var_Append	    Append more characters to an existing variable
     95  *			    in the given context. The variable needn't
     96  *			    exist already -- it will be created if it doesn't.
     97  *			    A space is placed between the old value and the
     98  *			    new one.
     99  *
    100  *	Var_Exists	    See if a variable exists.
    101  *
    102  *	Var_Value 	    Return the value of a variable in a context or
    103  *			    NULL if the variable is undefined.
    104  *
    105  *	Var_Subst 	    Substitute named variable, or all variables if
    106  *			    NULL in a string using
    107  *			    the given context as the top-most one. If the
    108  *			    third argument is non-zero, Parse_Error is
    109  *			    called if any variables are undefined.
    110  *
    111  *	Var_Parse 	    Parse a variable expansion from a string and
    112  *			    return the result and the number of characters
    113  *			    consumed.
    114  *
    115  *	Var_Delete	    Delete a variable in a context.
    116  *
    117  *	Var_Init  	    Initialize this module.
    118  *
    119  * Debugging:
    120  *	Var_Dump  	    Print out all variables defined in the given
    121  *			    context.
    122  *
    123  * XXX: There's a lot of duplication in these functions.
    124  */
    125 
    126 #include    <sys/stat.h>
    127 #ifndef NO_REGEX
    128 #include    <sys/types.h>
    129 #include    <regex.h>
    130 #endif
    131 #include    <ctype.h>
    132 #include    <inttypes.h>
    133 #include    <stdlib.h>
    134 #include    <limits.h>
    135 #include    <time.h>
    136 
    137 #include    "make.h"
    138 #include    "buf.h"
    139 #include    "dir.h"
    140 #include    "job.h"
    141 
    142 extern int makelevel;
    143 /*
    144  * This lets us tell if we have replaced the original environ
    145  * (which we cannot free).
    146  */
    147 char **savedEnv = NULL;
    148 
    149 /*
    150  * This is a harmless return value for Var_Parse that can be used by Var_Subst
    151  * to determine if there was an error in parsing -- easier than returning
    152  * a flag, as things outside this module don't give a hoot.
    153  */
    154 char 	var_Error[] = "";
    155 
    156 /*
    157  * Similar to var_Error, but returned when the 'errnum' flag for Var_Parse is
    158  * set false. Why not just use a constant? Well, gcc likes to condense
    159  * identical string instances...
    160  */
    161 static char	varNoError[] = "";
    162 
    163 /*
    164  * Internally, variables are contained in four different contexts.
    165  *	1) the environment. They may not be changed. If an environment
    166  *	    variable is appended-to, the result is placed in the global
    167  *	    context.
    168  *	2) the global context. Variables set in the Makefile are located in
    169  *	    the global context. It is the penultimate context searched when
    170  *	    substituting.
    171  *	3) the command-line context. All variables set on the command line
    172  *	   are placed in this context. They are UNALTERABLE once placed here.
    173  *	4) the local context. Each target has associated with it a context
    174  *	   list. On this list are located the structures describing such
    175  *	   local variables as $(@) and $(*)
    176  * The four contexts are searched in the reverse order from which they are
    177  * listed.
    178  */
    179 GNode          *VAR_GLOBAL;   /* variables from the makefile */
    180 GNode          *VAR_CMD;      /* variables defined on the command-line */
    181 
    182 #define FIND_CMD	0x1   /* look in VAR_CMD when searching */
    183 #define FIND_GLOBAL	0x2   /* look in VAR_GLOBAL as well */
    184 #define FIND_ENV  	0x4   /* look in the environment also */
    185 
    186 typedef struct Var {
    187     char          *name;	/* the variable's name */
    188     Buffer	  val;		/* its value */
    189     int		  flags;    	/* miscellaneous status flags */
    190 #define VAR_IN_USE	1   	    /* Variable's value currently being used.
    191 				     * Used to avoid recursion */
    192 #define VAR_FROM_ENV	2   	    /* Variable comes from the environment */
    193 #define VAR_JUNK  	4   	    /* Variable is a junk variable that
    194 				     * should be destroyed when done with
    195 				     * it. Used by Var_Parse for undefined,
    196 				     * modified variables */
    197 #define VAR_KEEP	8	    /* Variable is VAR_JUNK, but we found
    198 				     * a use for it in some modifier and
    199 				     * the value is therefore valid */
    200 #define VAR_EXPORTED	16 	    /* Variable is exported */
    201 #define VAR_REEXPORT	32	    /* Indicate if var needs re-export.
    202 				     * This would be true if it contains $'s
    203 				     */
    204 #define VAR_FROM_CMD	64 	    /* Variable came from command line */
    205 }  Var;
    206 
    207 /*
    208  * Exporting vars is expensive so skip it if we can
    209  */
    210 #define VAR_EXPORTED_NONE	0
    211 #define VAR_EXPORTED_YES	1
    212 #define VAR_EXPORTED_ALL	2
    213 static int var_exportedVars = VAR_EXPORTED_NONE;
    214 /*
    215  * We pass this to Var_Export when doing the initial export
    216  * or after updating an exported var.
    217  */
    218 #define VAR_EXPORT_PARENT 1
    219 
    220 /* Var*Pattern flags */
    221 #define VAR_SUB_GLOBAL	0x01	/* Apply substitution globally */
    222 #define VAR_SUB_ONE	0x02	/* Apply substitution to one word */
    223 #define VAR_SUB_MATCHED	0x04	/* There was a match */
    224 #define VAR_MATCH_START	0x08	/* Match at start of word */
    225 #define VAR_MATCH_END	0x10	/* Match at end of word */
    226 #define VAR_NOSUBST	0x20	/* don't expand vars in VarGetPattern */
    227 
    228 /* Var_Set flags */
    229 #define VAR_NO_EXPORT	0x01	/* do not export */
    230 
    231 typedef struct {
    232     /*
    233      * The following fields are set by Var_Parse() when it
    234      * encounters modifiers that need to keep state for use by
    235      * subsequent modifiers within the same variable expansion.
    236      */
    237     Byte	varSpace;	/* Word separator in expansions */
    238     Boolean	oneBigWord;	/* TRUE if we will treat the variable as a
    239 				 * single big word, even if it contains
    240 				 * embedded spaces (as opposed to the
    241 				 * usual behaviour of treating it as
    242 				 * several space-separated words). */
    243 } Var_Parse_State;
    244 
    245 /* struct passed as 'void *' to VarSubstitute() for ":S/lhs/rhs/",
    246  * to VarSYSVMatch() for ":lhs=rhs". */
    247 typedef struct {
    248     const char   *lhs;	    /* String to match */
    249     int		  leftLen; /* Length of string */
    250     const char   *rhs;	    /* Replacement string (w/ &'s removed) */
    251     int		  rightLen; /* Length of replacement */
    252     int		  flags;
    253 } VarPattern;
    254 
    255 /* struct passed as 'void *' to VarLoopExpand() for ":@tvar@str@" */
    256 typedef struct {
    257     GNode	*ctxt;		/* variable context */
    258     char	*tvar;		/* name of temp var */
    259     int		tvarLen;
    260     char	*str;		/* string to expand */
    261     int		strLen;
    262     int		errnum;		/* errnum for not defined */
    263 } VarLoop_t;
    264 
    265 #ifndef NO_REGEX
    266 /* struct passed as 'void *' to VarRESubstitute() for ":C///" */
    267 typedef struct {
    268     regex_t	   re;
    269     int		   nsub;
    270     regmatch_t 	  *matches;
    271     char 	  *replace;
    272     int		   flags;
    273 } VarREPattern;
    274 #endif
    275 
    276 /* struct passed to VarSelectWords() for ":[start..end]" */
    277 typedef struct {
    278     int		start;		/* first word to select */
    279     int		end;		/* last word to select */
    280 } VarSelectWords_t;
    281 
    282 static Var *VarFind(const char *, GNode *, int);
    283 static void VarAdd(const char *, const char *, GNode *);
    284 static Boolean VarHead(GNode *, Var_Parse_State *,
    285 			char *, Boolean, Buffer *, void *);
    286 static Boolean VarTail(GNode *, Var_Parse_State *,
    287 			char *, Boolean, Buffer *, void *);
    288 static Boolean VarSuffix(GNode *, Var_Parse_State *,
    289 			char *, Boolean, Buffer *, void *);
    290 static Boolean VarRoot(GNode *, Var_Parse_State *,
    291 			char *, Boolean, Buffer *, void *);
    292 static Boolean VarMatch(GNode *, Var_Parse_State *,
    293 			char *, Boolean, Buffer *, void *);
    294 #ifdef SYSVVARSUB
    295 static Boolean VarSYSVMatch(GNode *, Var_Parse_State *,
    296 			char *, Boolean, Buffer *, void *);
    297 #endif
    298 static Boolean VarNoMatch(GNode *, Var_Parse_State *,
    299 			char *, Boolean, Buffer *, void *);
    300 #ifndef NO_REGEX
    301 static void VarREError(int, regex_t *, const char *);
    302 static Boolean VarRESubstitute(GNode *, Var_Parse_State *,
    303 			char *, Boolean, Buffer *, void *);
    304 #endif
    305 static Boolean VarSubstitute(GNode *, Var_Parse_State *,
    306 			char *, Boolean, Buffer *, void *);
    307 static Boolean VarLoopExpand(GNode *, Var_Parse_State *,
    308 			char *, Boolean, Buffer *, void *);
    309 static char *VarGetPattern(GNode *, Var_Parse_State *,
    310 			   int, const char **, int, int *, int *,
    311 			   VarPattern *);
    312 static char *VarQuote(char *);
    313 static char *VarHash(char *);
    314 static char *VarModify(GNode *, Var_Parse_State *,
    315     const char *,
    316     Boolean (*)(GNode *, Var_Parse_State *, char *, Boolean, Buffer *, void *),
    317     void *);
    318 static char *VarOrder(const char *, const char);
    319 static char *VarUniq(const char *);
    320 static int VarWordCompare(const void *, const void *);
    321 static void VarPrintVar(void *);
    322 
    323 #define BROPEN	'{'
    324 #define BRCLOSE	'}'
    325 #define PROPEN	'('
    326 #define PRCLOSE	')'
    327 
    328 /*-
    329  *-----------------------------------------------------------------------
    330  * VarFind --
    331  *	Find the given variable in the given context and any other contexts
    332  *	indicated.
    333  *
    334  * Input:
    335  *	name		name to find
    336  *	ctxt		context in which to find it
    337  *	flags		FIND_GLOBAL set means to look in the
    338  *			VAR_GLOBAL context as well. FIND_CMD set means
    339  *			to look in the VAR_CMD context also. FIND_ENV
    340  *			set means to look in the environment
    341  *
    342  * Results:
    343  *	A pointer to the structure describing the desired variable or
    344  *	NULL if the variable does not exist.
    345  *
    346  * Side Effects:
    347  *	None
    348  *-----------------------------------------------------------------------
    349  */
    350 static Var *
    351 VarFind(const char *name, GNode *ctxt, int flags)
    352 {
    353     Hash_Entry         	*var;
    354     Var			*v;
    355 
    356 	/*
    357 	 * If the variable name begins with a '.', it could very well be one of
    358 	 * the local ones.  We check the name against all the local variables
    359 	 * and substitute the short version in for 'name' if it matches one of
    360 	 * them.
    361 	 */
    362 	if (*name == '.' && isupper((unsigned char) name[1]))
    363 		switch (name[1]) {
    364 		case 'A':
    365 			if (!strcmp(name, ".ALLSRC"))
    366 				name = ALLSRC;
    367 			if (!strcmp(name, ".ARCHIVE"))
    368 				name = ARCHIVE;
    369 			break;
    370 		case 'I':
    371 			if (!strcmp(name, ".IMPSRC"))
    372 				name = IMPSRC;
    373 			break;
    374 		case 'M':
    375 			if (!strcmp(name, ".MEMBER"))
    376 				name = MEMBER;
    377 			break;
    378 		case 'O':
    379 			if (!strcmp(name, ".OODATE"))
    380 				name = OODATE;
    381 			break;
    382 		case 'P':
    383 			if (!strcmp(name, ".PREFIX"))
    384 				name = PREFIX;
    385 			break;
    386 		case 'T':
    387 			if (!strcmp(name, ".TARGET"))
    388 				name = TARGET;
    389 			break;
    390 		}
    391 #ifdef notyet
    392     /* for compatibility with gmake */
    393     if (name[0] == '^' && name[1] == '\0')
    394 	    name = ALLSRC;
    395 #endif
    396 
    397     /*
    398      * First look for the variable in the given context. If it's not there,
    399      * look for it in VAR_CMD, VAR_GLOBAL and the environment, in that order,
    400      * depending on the FIND_* flags in 'flags'
    401      */
    402     var = Hash_FindEntry(&ctxt->context, name);
    403 
    404     if ((var == NULL) && (flags & FIND_CMD) && (ctxt != VAR_CMD)) {
    405 	var = Hash_FindEntry(&VAR_CMD->context, name);
    406     }
    407     if (!checkEnvFirst && (var == NULL) && (flags & FIND_GLOBAL) &&
    408 	(ctxt != VAR_GLOBAL))
    409     {
    410 	var = Hash_FindEntry(&VAR_GLOBAL->context, name);
    411     }
    412     if ((var == NULL) && (flags & FIND_ENV)) {
    413 	char *env;
    414 
    415 	if ((env = getenv(name)) != NULL) {
    416 	    int		len;
    417 
    418 	    v = bmake_malloc(sizeof(Var));
    419 	    v->name = bmake_strdup(name);
    420 
    421 	    len = strlen(env);
    422 
    423 	    Buf_Init(&v->val, len + 1);
    424 	    Buf_AddBytes(&v->val, len, env);
    425 
    426 	    v->flags = VAR_FROM_ENV;
    427 	    return (v);
    428 	} else if (checkEnvFirst && (flags & FIND_GLOBAL) &&
    429 		   (ctxt != VAR_GLOBAL))
    430 	{
    431 	    var = Hash_FindEntry(&VAR_GLOBAL->context, name);
    432 	    if (var == NULL) {
    433 		return NULL;
    434 	    } else {
    435 		return ((Var *)Hash_GetValue(var));
    436 	    }
    437 	} else {
    438 	    return NULL;
    439 	}
    440     } else if (var == NULL) {
    441 	return NULL;
    442     } else {
    443 	return ((Var *)Hash_GetValue(var));
    444     }
    445 }
    446 
    447 /*-
    448  *-----------------------------------------------------------------------
    449  * VarFreeEnv  --
    450  *	If the variable is an environment variable, free it
    451  *
    452  * Input:
    453  *	v		the variable
    454  *	destroy		true if the value buffer should be destroyed.
    455  *
    456  * Results:
    457  *	1 if it is an environment variable 0 ow.
    458  *
    459  * Side Effects:
    460  *	The variable is free'ed if it is an environent variable.
    461  *-----------------------------------------------------------------------
    462  */
    463 static Boolean
    464 VarFreeEnv(Var *v, Boolean destroy)
    465 {
    466     if ((v->flags & VAR_FROM_ENV) == 0)
    467 	return FALSE;
    468     free(v->name);
    469     Buf_Destroy(&v->val, destroy);
    470     free(v);
    471     return TRUE;
    472 }
    473 
    474 /*-
    475  *-----------------------------------------------------------------------
    476  * VarAdd  --
    477  *	Add a new variable of name name and value val to the given context
    478  *
    479  * Input:
    480  *	name		name of variable to add
    481  *	val		value to set it to
    482  *	ctxt		context in which to set it
    483  *
    484  * Results:
    485  *	None
    486  *
    487  * Side Effects:
    488  *	The new variable is placed at the front of the given context
    489  *	The name and val arguments are duplicated so they may
    490  *	safely be freed.
    491  *-----------------------------------------------------------------------
    492  */
    493 static void
    494 VarAdd(const char *name, const char *val, GNode *ctxt)
    495 {
    496     Var   	  *v;
    497     int		  len;
    498     Hash_Entry    *h;
    499 
    500     v = bmake_malloc(sizeof(Var));
    501 
    502     len = val ? strlen(val) : 0;
    503     Buf_Init(&v->val, len+1);
    504     Buf_AddBytes(&v->val, len, val);
    505 
    506     v->flags = 0;
    507 
    508     h = Hash_CreateEntry(&ctxt->context, name, NULL);
    509     Hash_SetValue(h, v);
    510     v->name = h->name;
    511     if (DEBUG(VAR)) {
    512 	fprintf(debug_file, "%s:%s = %s\n", ctxt->name, name, val);
    513     }
    514 }
    515 
    516 /*-
    517  *-----------------------------------------------------------------------
    518  * Var_Delete --
    519  *	Remove a variable from a context.
    520  *
    521  * Results:
    522  *	None.
    523  *
    524  * Side Effects:
    525  *	The Var structure is removed and freed.
    526  *
    527  *-----------------------------------------------------------------------
    528  */
    529 void
    530 Var_Delete(const char *name, GNode *ctxt)
    531 {
    532     Hash_Entry 	  *ln;
    533     char *cp;
    534 
    535     if (strchr(name, '$')) {
    536 	cp = Var_Subst(NULL, name, VAR_GLOBAL, 0);
    537     } else {
    538 	cp = (char *)name;
    539     }
    540     ln = Hash_FindEntry(&ctxt->context, cp);
    541     if (DEBUG(VAR)) {
    542 	fprintf(debug_file, "%s:delete %s%s\n",
    543 	    ctxt->name, cp, ln ? "" : " (not found)");
    544     }
    545     if (cp != name) {
    546 	free(cp);
    547     }
    548     if (ln != NULL) {
    549 	Var 	  *v;
    550 
    551 	v = (Var *)Hash_GetValue(ln);
    552 	if ((v->flags & VAR_EXPORTED)) {
    553 	    unsetenv(v->name);
    554 	}
    555 	if (strcmp(MAKE_EXPORTED, v->name) == 0) {
    556 	    var_exportedVars = VAR_EXPORTED_NONE;
    557 	}
    558 	if (v->name != ln->name)
    559 		free(v->name);
    560 	Hash_DeleteEntry(&ctxt->context, ln);
    561 	Buf_Destroy(&v->val, TRUE);
    562 	free(v);
    563     }
    564 }
    565 
    566 
    567 /*
    568  * Export a var.
    569  * We ignore make internal variables (those which start with '.')
    570  * Also we jump through some hoops to avoid calling setenv
    571  * more than necessary since it can leak.
    572  * We only manipulate flags of vars if 'parent' is set.
    573  */
    574 static int
    575 Var_Export1(const char *name, int parent)
    576 {
    577     char tmp[BUFSIZ];
    578     Var *v;
    579     char *val = NULL;
    580     int n;
    581 
    582     if (*name == '.')
    583 	return 0;			/* skip internals */
    584     if (!name[1]) {
    585 	/*
    586 	 * A single char.
    587 	 * If it is one of the vars that should only appear in
    588 	 * local context, skip it, else we can get Var_Subst
    589 	 * into a loop.
    590 	 */
    591 	switch (name[0]) {
    592 	case '@':
    593 	case '%':
    594 	case '*':
    595 	case '!':
    596 	    return 0;
    597 	}
    598     }
    599     v = VarFind(name, VAR_GLOBAL, 0);
    600     if (v == NULL) {
    601 	return 0;
    602     }
    603     if (!parent &&
    604 	(v->flags & (VAR_EXPORTED|VAR_REEXPORT)) == VAR_EXPORTED) {
    605 	return 0;			/* nothing to do */
    606     }
    607     val = Buf_GetAll(&v->val, NULL);
    608     if (strchr(val, '$')) {
    609 	if (parent) {
    610 	    /*
    611 	     * Flag this as something we need to re-export.
    612 	     * No point actually exporting it now though,
    613 	     * the child can do it at the last minute.
    614 	     */
    615 	    v->flags |= (VAR_EXPORTED|VAR_REEXPORT);
    616 	    return 1;
    617 	}
    618 	if (v->flags & VAR_IN_USE) {
    619 	    /*
    620 	     * We recursed while exporting in a child.
    621 	     * This isn't going to end well, just skip it.
    622 	     */
    623 	    return 0;
    624 	}
    625 	n = snprintf(tmp, sizeof(tmp), "${%s}", name);
    626 	if (n < (int)sizeof(tmp)) {
    627 	    val = Var_Subst(NULL, tmp, VAR_GLOBAL, 0);
    628 	    setenv(name, val, 1);
    629 	    free(val);
    630 	}
    631     } else {
    632 	if (parent) {
    633 	    v->flags &= ~VAR_REEXPORT;	/* once will do */
    634 	}
    635 	if (parent || !(v->flags & VAR_EXPORTED)) {
    636 	    setenv(name, val, 1);
    637 	}
    638     }
    639     /*
    640      * This is so Var_Set knows to call Var_Export again...
    641      */
    642     if (parent) {
    643 	v->flags |= VAR_EXPORTED;
    644     }
    645     return 1;
    646 }
    647 
    648 /*
    649  * This gets called from our children.
    650  */
    651 void
    652 Var_ExportVars(void)
    653 {
    654     char tmp[BUFSIZ];
    655     Hash_Entry         	*var;
    656     Hash_Search 	state;
    657     Var *v;
    658     char *val;
    659     int n;
    660 
    661     /*
    662      * Several make's support this sort of mechanism for tracking
    663      * recursion - but each uses a different name.
    664      * We allow the makefiles to update MAKELEVEL and ensure
    665      * children see a correctly incremented value.
    666      */
    667     snprintf(tmp, sizeof(tmp), "%d", makelevel + 1);
    668     setenv(MAKE_LEVEL_ENV, tmp, 1);
    669 
    670     if (VAR_EXPORTED_NONE == var_exportedVars)
    671 	return;
    672 
    673     if (VAR_EXPORTED_ALL == var_exportedVars) {
    674 	/*
    675 	 * Ouch! This is crazy...
    676 	 */
    677 	for (var = Hash_EnumFirst(&VAR_GLOBAL->context, &state);
    678 	     var != NULL;
    679 	     var = Hash_EnumNext(&state)) {
    680 	    v = (Var *)Hash_GetValue(var);
    681 	    Var_Export1(v->name, 0);
    682 	}
    683 	return;
    684     }
    685     /*
    686      * We have a number of exported vars,
    687      */
    688     n = snprintf(tmp, sizeof(tmp), "${" MAKE_EXPORTED ":O:u}");
    689     if (n < (int)sizeof(tmp)) {
    690 	char **av;
    691 	char *as;
    692 	int ac;
    693 	int i;
    694 
    695 	val = Var_Subst(NULL, tmp, VAR_GLOBAL, 0);
    696 	av = brk_string(val, &ac, FALSE, &as);
    697 	for (i = 0; i < ac; i++) {
    698 	    Var_Export1(av[i], 0);
    699 	}
    700 	free(val);
    701 	free(as);
    702 	free(av);
    703     }
    704 }
    705 
    706 /*
    707  * This is called when .export is seen or
    708  * .MAKE.EXPORTED is modified.
    709  * It is also called when any exported var is modified.
    710  */
    711 void
    712 Var_Export(char *str, int isExport)
    713 {
    714     char *name;
    715     char *val;
    716     char **av;
    717     char *as;
    718     int track;
    719     int ac;
    720     int i;
    721 
    722     if (isExport && (!str || !str[0])) {
    723 	var_exportedVars = VAR_EXPORTED_ALL; /* use with caution! */
    724 	return;
    725     }
    726 
    727     if (strncmp(str, "-env", 4) == 0) {
    728 	track = 0;
    729 	str += 4;
    730     } else {
    731 	track = VAR_EXPORT_PARENT;
    732     }
    733     val = Var_Subst(NULL, str, VAR_GLOBAL, 0);
    734     av = brk_string(val, &ac, FALSE, &as);
    735     for (i = 0; i < ac; i++) {
    736 	name = av[i];
    737 	if (!name[1]) {
    738 	    /*
    739 	     * A single char.
    740 	     * If it is one of the vars that should only appear in
    741 	     * local context, skip it, else we can get Var_Subst
    742 	     * into a loop.
    743 	     */
    744 	    switch (name[0]) {
    745 	    case '@':
    746 	    case '%':
    747 	    case '*':
    748 	    case '!':
    749 		continue;
    750 	    }
    751 	}
    752 	if (Var_Export1(name, track)) {
    753 	    if (VAR_EXPORTED_ALL != var_exportedVars)
    754 		var_exportedVars = VAR_EXPORTED_YES;
    755 	    if (isExport && track) {
    756 		Var_Append(MAKE_EXPORTED, name, VAR_GLOBAL);
    757 	    }
    758 	}
    759     }
    760     free(val);
    761     free(as);
    762     free(av);
    763 }
    764 
    765 
    766 /*
    767  * This is called when .unexport[-env] is seen.
    768  */
    769 extern char **environ;
    770 
    771 void
    772 Var_UnExport(char *str)
    773 {
    774     char tmp[BUFSIZ];
    775     char *vlist;
    776     char *cp;
    777     Boolean unexport_env;
    778     int n;
    779 
    780     if (!str || !str[0]) {
    781 	return; 			/* assert? */
    782     }
    783 
    784     vlist = NULL;
    785 
    786     str += 8;
    787     unexport_env = (strncmp(str, "-env", 4) == 0);
    788     if (unexport_env) {
    789 	char **newenv;
    790 
    791 	cp = getenv(MAKE_LEVEL_ENV);	/* we should preserve this */
    792 	if (environ == savedEnv) {
    793 	    /* we have been here before! */
    794 	    newenv = bmake_realloc(environ, 2 * sizeof(char *));
    795 	} else {
    796 	    if (savedEnv) {
    797 		free(savedEnv);
    798 		savedEnv = NULL;
    799 	    }
    800 	    newenv = bmake_malloc(2 * sizeof(char *));
    801 	}
    802 	if (!newenv)
    803 	    return;
    804 	/* Note: we cannot safely free() the original environ. */
    805 	environ = savedEnv = newenv;
    806 	newenv[0] = NULL;
    807 	newenv[1] = NULL;
    808 	setenv(MAKE_LEVEL_ENV, cp, 1);
    809     } else {
    810 	for (; *str != '\n' && isspace((unsigned char) *str); str++)
    811 	    continue;
    812 	if (str[0] && str[0] != '\n') {
    813 	    vlist = str;
    814 	}
    815     }
    816 
    817     if (!vlist) {
    818 	/* Using .MAKE.EXPORTED */
    819 	n = snprintf(tmp, sizeof(tmp), "${" MAKE_EXPORTED ":O:u}");
    820 	if (n < (int)sizeof(tmp)) {
    821 	    vlist = Var_Subst(NULL, tmp, VAR_GLOBAL, 0);
    822 	}
    823     }
    824     if (vlist) {
    825 	Var *v;
    826 	char **av;
    827 	char *as;
    828 	int ac;
    829 	int i;
    830 
    831 	av = brk_string(vlist, &ac, FALSE, &as);
    832 	for (i = 0; i < ac; i++) {
    833 	    v = VarFind(av[i], VAR_GLOBAL, 0);
    834 	    if (!v)
    835 		continue;
    836 	    if (!unexport_env &&
    837 		(v->flags & (VAR_EXPORTED|VAR_REEXPORT)) == VAR_EXPORTED) {
    838 		unsetenv(v->name);
    839 	    }
    840 	    v->flags &= ~(VAR_EXPORTED|VAR_REEXPORT);
    841 	    /*
    842 	     * If we are unexporting a list,
    843 	     * remove each one from .MAKE.EXPORTED.
    844 	     * If we are removing them all,
    845 	     * just delete .MAKE.EXPORTED below.
    846 	     */
    847 	    if (vlist == str) {
    848 		n = snprintf(tmp, sizeof(tmp),
    849 			     "${" MAKE_EXPORTED ":N%s}", v->name);
    850 		if (n < (int)sizeof(tmp)) {
    851 		    cp = Var_Subst(NULL, tmp, VAR_GLOBAL, 0);
    852 		    Var_Set(MAKE_EXPORTED, cp, VAR_GLOBAL, 0);
    853 		    free(cp);
    854 		}
    855 	    }
    856 	}
    857 	free(as);
    858 	free(av);
    859 	if (vlist != str) {
    860 	    Var_Delete(MAKE_EXPORTED, VAR_GLOBAL);
    861 	    free(vlist);
    862 	}
    863     }
    864 }
    865 
    866 /*-
    867  *-----------------------------------------------------------------------
    868  * Var_Set --
    869  *	Set the variable name to the value val in the given context.
    870  *
    871  * Input:
    872  *	name		name of variable to set
    873  *	val		value to give to the variable
    874  *	ctxt		context in which to set it
    875  *
    876  * Results:
    877  *	None.
    878  *
    879  * Side Effects:
    880  *	If the variable doesn't yet exist, a new record is created for it.
    881  *	Else the old value is freed and the new one stuck in its place
    882  *
    883  * Notes:
    884  *	The variable is searched for only in its context before being
    885  *	created in that context. I.e. if the context is VAR_GLOBAL,
    886  *	only VAR_GLOBAL->context is searched. Likewise if it is VAR_CMD, only
    887  *	VAR_CMD->context is searched. This is done to avoid the literally
    888  *	thousands of unnecessary strcmp's that used to be done to
    889  *	set, say, $(@) or $(<).
    890  *	If the context is VAR_GLOBAL though, we check if the variable
    891  *	was set in VAR_CMD from the command line and skip it if so.
    892  *-----------------------------------------------------------------------
    893  */
    894 void
    895 Var_Set(const char *name, const char *val, GNode *ctxt, int flags)
    896 {
    897     Var   *v;
    898     char *expanded_name = NULL;
    899 
    900     /*
    901      * We only look for a variable in the given context since anything set
    902      * here will override anything in a lower context, so there's not much
    903      * point in searching them all just to save a bit of memory...
    904      */
    905     if (strchr(name, '$') != NULL) {
    906 	expanded_name = Var_Subst(NULL, name, ctxt, 0);
    907 	if (expanded_name[0] == 0) {
    908 	    if (DEBUG(VAR)) {
    909 		fprintf(debug_file, "Var_Set(\"%s\", \"%s\", ...) "
    910 			"name expands to empty string - ignored\n",
    911 			name, val);
    912 	    }
    913 	    free(expanded_name);
    914 	    return;
    915 	}
    916 	name = expanded_name;
    917     }
    918     if (ctxt == VAR_GLOBAL) {
    919 	v = VarFind(name, VAR_CMD, 0);
    920 	if (v != NULL) {
    921 	    if ((v->flags & VAR_FROM_CMD)) {
    922 		if (DEBUG(VAR)) {
    923 		    fprintf(debug_file, "%s:%s = %s ignored!\n", ctxt->name, name, val);
    924 		}
    925 		goto out;
    926 	    }
    927 	    VarFreeEnv(v, TRUE);
    928 	}
    929     }
    930     v = VarFind(name, ctxt, 0);
    931     if (v == NULL) {
    932 	VarAdd(name, val, ctxt);
    933     } else {
    934 	Buf_Empty(&v->val);
    935 	Buf_AddBytes(&v->val, strlen(val), val);
    936 
    937 	if (DEBUG(VAR)) {
    938 	    fprintf(debug_file, "%s:%s = %s\n", ctxt->name, name, val);
    939 	}
    940 	if ((v->flags & VAR_EXPORTED)) {
    941 	    Var_Export1(name, VAR_EXPORT_PARENT);
    942 	}
    943     }
    944     /*
    945      * Any variables given on the command line are automatically exported
    946      * to the environment (as per POSIX standard)
    947      */
    948     if (ctxt == VAR_CMD && (flags & VAR_NO_EXPORT) == 0) {
    949 	if (v == NULL) {
    950 	    /* we just added it */
    951 	    v = VarFind(name, ctxt, 0);
    952 	}
    953 	if (v != NULL)
    954 	    v->flags |= VAR_FROM_CMD;
    955 	/*
    956 	 * If requested, don't export these in the environment
    957 	 * individually.  We still put them in MAKEOVERRIDES so
    958 	 * that the command-line settings continue to override
    959 	 * Makefile settings.
    960 	 */
    961 	if (varNoExportEnv != TRUE)
    962 	    setenv(name, val, 1);
    963 
    964 	Var_Append(MAKEOVERRIDES, name, VAR_GLOBAL);
    965     }
    966 
    967  out:
    968     if (expanded_name != NULL)
    969 	free(expanded_name);
    970     if (v != NULL)
    971 	VarFreeEnv(v, TRUE);
    972 }
    973 
    974 /*-
    975  *-----------------------------------------------------------------------
    976  * Var_Append --
    977  *	The variable of the given name has the given value appended to it in
    978  *	the given context.
    979  *
    980  * Input:
    981  *	name		name of variable to modify
    982  *	val		String to append to it
    983  *	ctxt		Context in which this should occur
    984  *
    985  * Results:
    986  *	None
    987  *
    988  * Side Effects:
    989  *	If the variable doesn't exist, it is created. Else the strings
    990  *	are concatenated (with a space in between).
    991  *
    992  * Notes:
    993  *	Only if the variable is being sought in the global context is the
    994  *	environment searched.
    995  *	XXX: Knows its calling circumstances in that if called with ctxt
    996  *	an actual target, it will only search that context since only
    997  *	a local variable could be being appended to. This is actually
    998  *	a big win and must be tolerated.
    999  *-----------------------------------------------------------------------
   1000  */
   1001 void
   1002 Var_Append(const char *name, const char *val, GNode *ctxt)
   1003 {
   1004     Var		   *v;
   1005     Hash_Entry	   *h;
   1006     char *expanded_name = NULL;
   1007 
   1008     if (strchr(name, '$') != NULL) {
   1009 	expanded_name = Var_Subst(NULL, name, ctxt, 0);
   1010 	if (expanded_name[0] == 0) {
   1011 	    if (DEBUG(VAR)) {
   1012 		fprintf(debug_file, "Var_Append(\"%s\", \"%s\", ...) "
   1013 			"name expands to empty string - ignored\n",
   1014 			name, val);
   1015 	    }
   1016 	    free(expanded_name);
   1017 	    return;
   1018 	}
   1019 	name = expanded_name;
   1020     }
   1021 
   1022     v = VarFind(name, ctxt, (ctxt == VAR_GLOBAL) ? FIND_ENV : 0);
   1023 
   1024     if (v == NULL) {
   1025 	VarAdd(name, val, ctxt);
   1026     } else {
   1027 	Buf_AddByte(&v->val, ' ');
   1028 	Buf_AddBytes(&v->val, strlen(val), val);
   1029 
   1030 	if (DEBUG(VAR)) {
   1031 	    fprintf(debug_file, "%s:%s = %s\n", ctxt->name, name,
   1032 		   Buf_GetAll(&v->val, NULL));
   1033 	}
   1034 
   1035 	if (v->flags & VAR_FROM_ENV) {
   1036 	    /*
   1037 	     * If the original variable came from the environment, we
   1038 	     * have to install it in the global context (we could place
   1039 	     * it in the environment, but then we should provide a way to
   1040 	     * export other variables...)
   1041 	     */
   1042 	    v->flags &= ~VAR_FROM_ENV;
   1043 	    h = Hash_CreateEntry(&ctxt->context, name, NULL);
   1044 	    Hash_SetValue(h, v);
   1045 	}
   1046     }
   1047     if (expanded_name != NULL)
   1048 	free(expanded_name);
   1049 }
   1050 
   1051 /*-
   1052  *-----------------------------------------------------------------------
   1053  * Var_Exists --
   1054  *	See if the given variable exists.
   1055  *
   1056  * Input:
   1057  *	name		Variable to find
   1058  *	ctxt		Context in which to start search
   1059  *
   1060  * Results:
   1061  *	TRUE if it does, FALSE if it doesn't
   1062  *
   1063  * Side Effects:
   1064  *	None.
   1065  *
   1066  *-----------------------------------------------------------------------
   1067  */
   1068 Boolean
   1069 Var_Exists(const char *name, GNode *ctxt)
   1070 {
   1071     Var		  *v;
   1072     char          *cp;
   1073 
   1074     if ((cp = strchr(name, '$')) != NULL) {
   1075 	cp = Var_Subst(NULL, name, ctxt, FALSE);
   1076     }
   1077     v = VarFind(cp ? cp : name, ctxt, FIND_CMD|FIND_GLOBAL|FIND_ENV);
   1078     if (cp != NULL) {
   1079 	free(cp);
   1080     }
   1081     if (v == NULL) {
   1082 	return(FALSE);
   1083     } else {
   1084 	(void)VarFreeEnv(v, TRUE);
   1085     }
   1086     return(TRUE);
   1087 }
   1088 
   1089 /*-
   1090  *-----------------------------------------------------------------------
   1091  * Var_Value --
   1092  *	Return the value of the named variable in the given context
   1093  *
   1094  * Input:
   1095  *	name		name to find
   1096  *	ctxt		context in which to search for it
   1097  *
   1098  * Results:
   1099  *	The value if the variable exists, NULL if it doesn't
   1100  *
   1101  * Side Effects:
   1102  *	None
   1103  *-----------------------------------------------------------------------
   1104  */
   1105 char *
   1106 Var_Value(const char *name, GNode *ctxt, char **frp)
   1107 {
   1108     Var            *v;
   1109 
   1110     v = VarFind(name, ctxt, FIND_ENV | FIND_GLOBAL | FIND_CMD);
   1111     *frp = NULL;
   1112     if (v != NULL) {
   1113 	char *p = (Buf_GetAll(&v->val, NULL));
   1114 	if (VarFreeEnv(v, FALSE))
   1115 	    *frp = p;
   1116 	return p;
   1117     } else {
   1118 	return NULL;
   1119     }
   1120 }
   1121 
   1122 /*-
   1123  *-----------------------------------------------------------------------
   1124  * VarHead --
   1125  *	Remove the tail of the given word and place the result in the given
   1126  *	buffer.
   1127  *
   1128  * Input:
   1129  *	word		Word to trim
   1130  *	addSpace	True if need to add a space to the buffer
   1131  *			before sticking in the head
   1132  *	buf		Buffer in which to store it
   1133  *
   1134  * Results:
   1135  *	TRUE if characters were added to the buffer (a space needs to be
   1136  *	added to the buffer before the next word).
   1137  *
   1138  * Side Effects:
   1139  *	The trimmed word is added to the buffer.
   1140  *
   1141  *-----------------------------------------------------------------------
   1142  */
   1143 static Boolean
   1144 VarHead(GNode *ctx MAKE_ATTR_UNUSED, Var_Parse_State *vpstate,
   1145 	char *word, Boolean addSpace, Buffer *buf,
   1146 	void *dummy)
   1147 {
   1148     char *slash;
   1149 
   1150     slash = strrchr(word, '/');
   1151     if (slash != NULL) {
   1152 	if (addSpace && vpstate->varSpace) {
   1153 	    Buf_AddByte(buf, vpstate->varSpace);
   1154 	}
   1155 	*slash = '\0';
   1156 	Buf_AddBytes(buf, strlen(word), word);
   1157 	*slash = '/';
   1158 	return (TRUE);
   1159     } else {
   1160 	/*
   1161 	 * If no directory part, give . (q.v. the POSIX standard)
   1162 	 */
   1163 	if (addSpace && vpstate->varSpace)
   1164 	    Buf_AddByte(buf, vpstate->varSpace);
   1165 	Buf_AddByte(buf, '.');
   1166     }
   1167     return(dummy ? TRUE : TRUE);
   1168 }
   1169 
   1170 /*-
   1171  *-----------------------------------------------------------------------
   1172  * VarTail --
   1173  *	Remove the head of the given word and place the result in the given
   1174  *	buffer.
   1175  *
   1176  * Input:
   1177  *	word		Word to trim
   1178  *	addSpace	True if need to add a space to the buffer
   1179  *			before adding the tail
   1180  *	buf		Buffer in which to store it
   1181  *
   1182  * Results:
   1183  *	TRUE if characters were added to the buffer (a space needs to be
   1184  *	added to the buffer before the next word).
   1185  *
   1186  * Side Effects:
   1187  *	The trimmed word is added to the buffer.
   1188  *
   1189  *-----------------------------------------------------------------------
   1190  */
   1191 static Boolean
   1192 VarTail(GNode *ctx MAKE_ATTR_UNUSED, Var_Parse_State *vpstate,
   1193 	char *word, Boolean addSpace, Buffer *buf,
   1194 	void *dummy)
   1195 {
   1196     char *slash;
   1197 
   1198     if (addSpace && vpstate->varSpace) {
   1199 	Buf_AddByte(buf, vpstate->varSpace);
   1200     }
   1201 
   1202     slash = strrchr(word, '/');
   1203     if (slash != NULL) {
   1204 	*slash++ = '\0';
   1205 	Buf_AddBytes(buf, strlen(slash), slash);
   1206 	slash[-1] = '/';
   1207     } else {
   1208 	Buf_AddBytes(buf, strlen(word), word);
   1209     }
   1210     return (dummy ? TRUE : TRUE);
   1211 }
   1212 
   1213 /*-
   1214  *-----------------------------------------------------------------------
   1215  * VarSuffix --
   1216  *	Place the suffix of the given word in the given buffer.
   1217  *
   1218  * Input:
   1219  *	word		Word to trim
   1220  *	addSpace	TRUE if need to add a space before placing the
   1221  *			suffix in the buffer
   1222  *	buf		Buffer in which to store it
   1223  *
   1224  * Results:
   1225  *	TRUE if characters were added to the buffer (a space needs to be
   1226  *	added to the buffer before the next word).
   1227  *
   1228  * Side Effects:
   1229  *	The suffix from the word is placed in the buffer.
   1230  *
   1231  *-----------------------------------------------------------------------
   1232  */
   1233 static Boolean
   1234 VarSuffix(GNode *ctx MAKE_ATTR_UNUSED, Var_Parse_State *vpstate,
   1235 	  char *word, Boolean addSpace, Buffer *buf,
   1236 	  void *dummy)
   1237 {
   1238     char *dot;
   1239 
   1240     dot = strrchr(word, '.');
   1241     if (dot != NULL) {
   1242 	if (addSpace && vpstate->varSpace) {
   1243 	    Buf_AddByte(buf, vpstate->varSpace);
   1244 	}
   1245 	*dot++ = '\0';
   1246 	Buf_AddBytes(buf, strlen(dot), dot);
   1247 	dot[-1] = '.';
   1248 	addSpace = TRUE;
   1249     }
   1250     return (dummy ? addSpace : addSpace);
   1251 }
   1252 
   1253 /*-
   1254  *-----------------------------------------------------------------------
   1255  * VarRoot --
   1256  *	Remove the suffix of the given word and place the result in the
   1257  *	buffer.
   1258  *
   1259  * Input:
   1260  *	word		Word to trim
   1261  *	addSpace	TRUE if need to add a space to the buffer
   1262  *			before placing the root in it
   1263  *	buf		Buffer in which to store it
   1264  *
   1265  * Results:
   1266  *	TRUE if characters were added to the buffer (a space needs to be
   1267  *	added to the buffer before the next word).
   1268  *
   1269  * Side Effects:
   1270  *	The trimmed word is added to the buffer.
   1271  *
   1272  *-----------------------------------------------------------------------
   1273  */
   1274 static Boolean
   1275 VarRoot(GNode *ctx MAKE_ATTR_UNUSED, Var_Parse_State *vpstate,
   1276 	char *word, Boolean addSpace, Buffer *buf,
   1277 	void *dummy)
   1278 {
   1279     char *dot;
   1280 
   1281     if (addSpace && vpstate->varSpace) {
   1282 	Buf_AddByte(buf, vpstate->varSpace);
   1283     }
   1284 
   1285     dot = strrchr(word, '.');
   1286     if (dot != NULL) {
   1287 	*dot = '\0';
   1288 	Buf_AddBytes(buf, strlen(word), word);
   1289 	*dot = '.';
   1290     } else {
   1291 	Buf_AddBytes(buf, strlen(word), word);
   1292     }
   1293     return (dummy ? TRUE : TRUE);
   1294 }
   1295 
   1296 /*-
   1297  *-----------------------------------------------------------------------
   1298  * VarMatch --
   1299  *	Place the word in the buffer if it matches the given pattern.
   1300  *	Callback function for VarModify to implement the :M modifier.
   1301  *
   1302  * Input:
   1303  *	word		Word to examine
   1304  *	addSpace	TRUE if need to add a space to the buffer
   1305  *			before adding the word, if it matches
   1306  *	buf		Buffer in which to store it
   1307  *	pattern		Pattern the word must match
   1308  *
   1309  * Results:
   1310  *	TRUE if a space should be placed in the buffer before the next
   1311  *	word.
   1312  *
   1313  * Side Effects:
   1314  *	The word may be copied to the buffer.
   1315  *
   1316  *-----------------------------------------------------------------------
   1317  */
   1318 static Boolean
   1319 VarMatch(GNode *ctx MAKE_ATTR_UNUSED, Var_Parse_State *vpstate,
   1320 	 char *word, Boolean addSpace, Buffer *buf,
   1321 	 void *pattern)
   1322 {
   1323     if (DEBUG(VAR))
   1324 	fprintf(debug_file, "VarMatch [%s] [%s]\n", word, (char *)pattern);
   1325     if (Str_Match(word, (char *)pattern)) {
   1326 	if (addSpace && vpstate->varSpace) {
   1327 	    Buf_AddByte(buf, vpstate->varSpace);
   1328 	}
   1329 	addSpace = TRUE;
   1330 	Buf_AddBytes(buf, strlen(word), word);
   1331     }
   1332     return(addSpace);
   1333 }
   1334 
   1335 #ifdef SYSVVARSUB
   1336 /*-
   1337  *-----------------------------------------------------------------------
   1338  * VarSYSVMatch --
   1339  *	Place the word in the buffer if it matches the given pattern.
   1340  *	Callback function for VarModify to implement the System V %
   1341  *	modifiers.
   1342  *
   1343  * Input:
   1344  *	word		Word to examine
   1345  *	addSpace	TRUE if need to add a space to the buffer
   1346  *			before adding the word, if it matches
   1347  *	buf		Buffer in which to store it
   1348  *	patp		Pattern the word must match
   1349  *
   1350  * Results:
   1351  *	TRUE if a space should be placed in the buffer before the next
   1352  *	word.
   1353  *
   1354  * Side Effects:
   1355  *	The word may be copied to the buffer.
   1356  *
   1357  *-----------------------------------------------------------------------
   1358  */
   1359 static Boolean
   1360 VarSYSVMatch(GNode *ctx, Var_Parse_State *vpstate,
   1361 	     char *word, Boolean addSpace, Buffer *buf,
   1362 	     void *patp)
   1363 {
   1364     int len;
   1365     char *ptr;
   1366     VarPattern 	  *pat = (VarPattern *)patp;
   1367     char *varexp;
   1368 
   1369     if (addSpace && vpstate->varSpace)
   1370 	Buf_AddByte(buf, vpstate->varSpace);
   1371 
   1372     addSpace = TRUE;
   1373 
   1374     if ((ptr = Str_SYSVMatch(word, pat->lhs, &len)) != NULL) {
   1375         varexp = Var_Subst(NULL, pat->rhs, ctx, 0);
   1376 	Str_SYSVSubst(buf, varexp, ptr, len);
   1377 	free(varexp);
   1378     } else {
   1379 	Buf_AddBytes(buf, strlen(word), word);
   1380     }
   1381 
   1382     return(addSpace);
   1383 }
   1384 #endif
   1385 
   1386 
   1387 /*-
   1388  *-----------------------------------------------------------------------
   1389  * VarNoMatch --
   1390  *	Place the word in the buffer if it doesn't match the given pattern.
   1391  *	Callback function for VarModify to implement the :N modifier.
   1392  *
   1393  * Input:
   1394  *	word		Word to examine
   1395  *	addSpace	TRUE if need to add a space to the buffer
   1396  *			before adding the word, if it matches
   1397  *	buf		Buffer in which to store it
   1398  *	pattern		Pattern the word must match
   1399  *
   1400  * Results:
   1401  *	TRUE if a space should be placed in the buffer before the next
   1402  *	word.
   1403  *
   1404  * Side Effects:
   1405  *	The word may be copied to the buffer.
   1406  *
   1407  *-----------------------------------------------------------------------
   1408  */
   1409 static Boolean
   1410 VarNoMatch(GNode *ctx MAKE_ATTR_UNUSED, Var_Parse_State *vpstate,
   1411 	   char *word, Boolean addSpace, Buffer *buf,
   1412 	   void *pattern)
   1413 {
   1414     if (!Str_Match(word, (char *)pattern)) {
   1415 	if (addSpace && vpstate->varSpace) {
   1416 	    Buf_AddByte(buf, vpstate->varSpace);
   1417 	}
   1418 	addSpace = TRUE;
   1419 	Buf_AddBytes(buf, strlen(word), word);
   1420     }
   1421     return(addSpace);
   1422 }
   1423 
   1424 
   1425 /*-
   1426  *-----------------------------------------------------------------------
   1427  * VarSubstitute --
   1428  *	Perform a string-substitution on the given word, placing the
   1429  *	result in the passed buffer.
   1430  *
   1431  * Input:
   1432  *	word		Word to modify
   1433  *	addSpace	True if space should be added before
   1434  *			other characters
   1435  *	buf		Buffer for result
   1436  *	patternp	Pattern for substitution
   1437  *
   1438  * Results:
   1439  *	TRUE if a space is needed before more characters are added.
   1440  *
   1441  * Side Effects:
   1442  *	None.
   1443  *
   1444  *-----------------------------------------------------------------------
   1445  */
   1446 static Boolean
   1447 VarSubstitute(GNode *ctx MAKE_ATTR_UNUSED, Var_Parse_State *vpstate,
   1448 	      char *word, Boolean addSpace, Buffer *buf,
   1449 	      void *patternp)
   1450 {
   1451     int  	wordLen;    /* Length of word */
   1452     char 	*cp;	    /* General pointer */
   1453     VarPattern	*pattern = (VarPattern *)patternp;
   1454 
   1455     wordLen = strlen(word);
   1456     if ((pattern->flags & (VAR_SUB_ONE|VAR_SUB_MATCHED)) !=
   1457 	(VAR_SUB_ONE|VAR_SUB_MATCHED)) {
   1458 	/*
   1459 	 * Still substituting -- break it down into simple anchored cases
   1460 	 * and if none of them fits, perform the general substitution case.
   1461 	 */
   1462 	if ((pattern->flags & VAR_MATCH_START) &&
   1463 	    (strncmp(word, pattern->lhs, pattern->leftLen) == 0)) {
   1464 		/*
   1465 		 * Anchored at start and beginning of word matches pattern
   1466 		 */
   1467 		if ((pattern->flags & VAR_MATCH_END) &&
   1468 		    (wordLen == pattern->leftLen)) {
   1469 			/*
   1470 			 * Also anchored at end and matches to the end (word
   1471 			 * is same length as pattern) add space and rhs only
   1472 			 * if rhs is non-null.
   1473 			 */
   1474 			if (pattern->rightLen != 0) {
   1475 			    if (addSpace && vpstate->varSpace) {
   1476 				Buf_AddByte(buf, vpstate->varSpace);
   1477 			    }
   1478 			    addSpace = TRUE;
   1479 			    Buf_AddBytes(buf, pattern->rightLen, pattern->rhs);
   1480 			}
   1481 			pattern->flags |= VAR_SUB_MATCHED;
   1482 		} else if (pattern->flags & VAR_MATCH_END) {
   1483 		    /*
   1484 		     * Doesn't match to end -- copy word wholesale
   1485 		     */
   1486 		    goto nosub;
   1487 		} else {
   1488 		    /*
   1489 		     * Matches at start but need to copy in trailing characters
   1490 		     */
   1491 		    if ((pattern->rightLen + wordLen - pattern->leftLen) != 0){
   1492 			if (addSpace && vpstate->varSpace) {
   1493 			    Buf_AddByte(buf, vpstate->varSpace);
   1494 			}
   1495 			addSpace = TRUE;
   1496 		    }
   1497 		    Buf_AddBytes(buf, pattern->rightLen, pattern->rhs);
   1498 		    Buf_AddBytes(buf, wordLen - pattern->leftLen,
   1499 				 (word + pattern->leftLen));
   1500 		    pattern->flags |= VAR_SUB_MATCHED;
   1501 		}
   1502 	} else if (pattern->flags & VAR_MATCH_START) {
   1503 	    /*
   1504 	     * Had to match at start of word and didn't -- copy whole word.
   1505 	     */
   1506 	    goto nosub;
   1507 	} else if (pattern->flags & VAR_MATCH_END) {
   1508 	    /*
   1509 	     * Anchored at end, Find only place match could occur (leftLen
   1510 	     * characters from the end of the word) and see if it does. Note
   1511 	     * that because the $ will be left at the end of the lhs, we have
   1512 	     * to use strncmp.
   1513 	     */
   1514 	    cp = word + (wordLen - pattern->leftLen);
   1515 	    if ((cp >= word) &&
   1516 		(strncmp(cp, pattern->lhs, pattern->leftLen) == 0)) {
   1517 		/*
   1518 		 * Match found. If we will place characters in the buffer,
   1519 		 * add a space before hand as indicated by addSpace, then
   1520 		 * stuff in the initial, unmatched part of the word followed
   1521 		 * by the right-hand-side.
   1522 		 */
   1523 		if (((cp - word) + pattern->rightLen) != 0) {
   1524 		    if (addSpace && vpstate->varSpace) {
   1525 			Buf_AddByte(buf, vpstate->varSpace);
   1526 		    }
   1527 		    addSpace = TRUE;
   1528 		}
   1529 		Buf_AddBytes(buf, cp - word, word);
   1530 		Buf_AddBytes(buf, pattern->rightLen, pattern->rhs);
   1531 		pattern->flags |= VAR_SUB_MATCHED;
   1532 	    } else {
   1533 		/*
   1534 		 * Had to match at end and didn't. Copy entire word.
   1535 		 */
   1536 		goto nosub;
   1537 	    }
   1538 	} else {
   1539 	    /*
   1540 	     * Pattern is unanchored: search for the pattern in the word using
   1541 	     * String_FindSubstring, copying unmatched portions and the
   1542 	     * right-hand-side for each match found, handling non-global
   1543 	     * substitutions correctly, etc. When the loop is done, any
   1544 	     * remaining part of the word (word and wordLen are adjusted
   1545 	     * accordingly through the loop) is copied straight into the
   1546 	     * buffer.
   1547 	     * addSpace is set FALSE as soon as a space is added to the
   1548 	     * buffer.
   1549 	     */
   1550 	    Boolean done;
   1551 	    int origSize;
   1552 
   1553 	    done = FALSE;
   1554 	    origSize = Buf_Size(buf);
   1555 	    while (!done) {
   1556 		cp = Str_FindSubstring(word, pattern->lhs);
   1557 		if (cp != NULL) {
   1558 		    if (addSpace && (((cp - word) + pattern->rightLen) != 0)){
   1559 			Buf_AddByte(buf, vpstate->varSpace);
   1560 			addSpace = FALSE;
   1561 		    }
   1562 		    Buf_AddBytes(buf, cp-word, word);
   1563 		    Buf_AddBytes(buf, pattern->rightLen, pattern->rhs);
   1564 		    wordLen -= (cp - word) + pattern->leftLen;
   1565 		    word = cp + pattern->leftLen;
   1566 		    if (wordLen == 0) {
   1567 			done = TRUE;
   1568 		    }
   1569 		    if ((pattern->flags & VAR_SUB_GLOBAL) == 0) {
   1570 			done = TRUE;
   1571 		    }
   1572 		    pattern->flags |= VAR_SUB_MATCHED;
   1573 		} else {
   1574 		    done = TRUE;
   1575 		}
   1576 	    }
   1577 	    if (wordLen != 0) {
   1578 		if (addSpace && vpstate->varSpace) {
   1579 		    Buf_AddByte(buf, vpstate->varSpace);
   1580 		}
   1581 		Buf_AddBytes(buf, wordLen, word);
   1582 	    }
   1583 	    /*
   1584 	     * If added characters to the buffer, need to add a space
   1585 	     * before we add any more. If we didn't add any, just return
   1586 	     * the previous value of addSpace.
   1587 	     */
   1588 	    return ((Buf_Size(buf) != origSize) || addSpace);
   1589 	}
   1590 	return (addSpace);
   1591     }
   1592  nosub:
   1593     if (addSpace && vpstate->varSpace) {
   1594 	Buf_AddByte(buf, vpstate->varSpace);
   1595     }
   1596     Buf_AddBytes(buf, wordLen, word);
   1597     return(TRUE);
   1598 }
   1599 
   1600 #ifndef NO_REGEX
   1601 /*-
   1602  *-----------------------------------------------------------------------
   1603  * VarREError --
   1604  *	Print the error caused by a regcomp or regexec call.
   1605  *
   1606  * Results:
   1607  *	None.
   1608  *
   1609  * Side Effects:
   1610  *	An error gets printed.
   1611  *
   1612  *-----------------------------------------------------------------------
   1613  */
   1614 static void
   1615 VarREError(int errnum, regex_t *pat, const char *str)
   1616 {
   1617     char *errbuf;
   1618     int errlen;
   1619 
   1620     errlen = regerror(errnum, pat, 0, 0);
   1621     errbuf = bmake_malloc(errlen);
   1622     regerror(errnum, pat, errbuf, errlen);
   1623     Error("%s: %s", str, errbuf);
   1624     free(errbuf);
   1625 }
   1626 
   1627 
   1628 /*-
   1629  *-----------------------------------------------------------------------
   1630  * VarRESubstitute --
   1631  *	Perform a regex substitution on the given word, placing the
   1632  *	result in the passed buffer.
   1633  *
   1634  * Results:
   1635  *	TRUE if a space is needed before more characters are added.
   1636  *
   1637  * Side Effects:
   1638  *	None.
   1639  *
   1640  *-----------------------------------------------------------------------
   1641  */
   1642 static Boolean
   1643 VarRESubstitute(GNode *ctx MAKE_ATTR_UNUSED,
   1644 		Var_Parse_State *vpstate MAKE_ATTR_UNUSED,
   1645 		char *word, Boolean addSpace, Buffer *buf,
   1646 		void *patternp)
   1647 {
   1648     VarREPattern *pat;
   1649     int xrv;
   1650     char *wp;
   1651     char *rp;
   1652     int added;
   1653     int flags = 0;
   1654 
   1655 #define MAYBE_ADD_SPACE()		\
   1656 	if (addSpace && !added)		\
   1657 	    Buf_AddByte(buf, ' ');	\
   1658 	added = 1
   1659 
   1660     added = 0;
   1661     wp = word;
   1662     pat = patternp;
   1663 
   1664     if ((pat->flags & (VAR_SUB_ONE|VAR_SUB_MATCHED)) ==
   1665 	(VAR_SUB_ONE|VAR_SUB_MATCHED))
   1666 	xrv = REG_NOMATCH;
   1667     else {
   1668     tryagain:
   1669 	xrv = regexec(&pat->re, wp, pat->nsub, pat->matches, flags);
   1670     }
   1671 
   1672     switch (xrv) {
   1673     case 0:
   1674 	pat->flags |= VAR_SUB_MATCHED;
   1675 	if (pat->matches[0].rm_so > 0) {
   1676 	    MAYBE_ADD_SPACE();
   1677 	    Buf_AddBytes(buf, pat->matches[0].rm_so, wp);
   1678 	}
   1679 
   1680 	for (rp = pat->replace; *rp; rp++) {
   1681 	    if ((*rp == '\\') && ((rp[1] == '&') || (rp[1] == '\\'))) {
   1682 		MAYBE_ADD_SPACE();
   1683 		Buf_AddByte(buf,rp[1]);
   1684 		rp++;
   1685 	    }
   1686 	    else if ((*rp == '&') ||
   1687 		((*rp == '\\') && isdigit((unsigned char)rp[1]))) {
   1688 		int n;
   1689 		const char *subbuf;
   1690 		int sublen;
   1691 		char errstr[3];
   1692 
   1693 		if (*rp == '&') {
   1694 		    n = 0;
   1695 		    errstr[0] = '&';
   1696 		    errstr[1] = '\0';
   1697 		} else {
   1698 		    n = rp[1] - '0';
   1699 		    errstr[0] = '\\';
   1700 		    errstr[1] = rp[1];
   1701 		    errstr[2] = '\0';
   1702 		    rp++;
   1703 		}
   1704 
   1705 		if (n > pat->nsub) {
   1706 		    Error("No subexpression %s", &errstr[0]);
   1707 		    subbuf = "";
   1708 		    sublen = 0;
   1709 		} else if ((pat->matches[n].rm_so == -1) &&
   1710 			   (pat->matches[n].rm_eo == -1)) {
   1711 		    Error("No match for subexpression %s", &errstr[0]);
   1712 		    subbuf = "";
   1713 		    sublen = 0;
   1714 	        } else {
   1715 		    subbuf = wp + pat->matches[n].rm_so;
   1716 		    sublen = pat->matches[n].rm_eo - pat->matches[n].rm_so;
   1717 		}
   1718 
   1719 		if (sublen > 0) {
   1720 		    MAYBE_ADD_SPACE();
   1721 		    Buf_AddBytes(buf, sublen, subbuf);
   1722 		}
   1723 	    } else {
   1724 		MAYBE_ADD_SPACE();
   1725 		Buf_AddByte(buf, *rp);
   1726 	    }
   1727 	}
   1728 	wp += pat->matches[0].rm_eo;
   1729 	if (pat->flags & VAR_SUB_GLOBAL) {
   1730 	    flags |= REG_NOTBOL;
   1731 	    if (pat->matches[0].rm_so == 0 && pat->matches[0].rm_eo == 0) {
   1732 		MAYBE_ADD_SPACE();
   1733 		Buf_AddByte(buf, *wp);
   1734 		wp++;
   1735 
   1736 	    }
   1737 	    if (*wp)
   1738 		goto tryagain;
   1739 	}
   1740 	if (*wp) {
   1741 	    MAYBE_ADD_SPACE();
   1742 	    Buf_AddBytes(buf, strlen(wp), wp);
   1743 	}
   1744 	break;
   1745     default:
   1746 	VarREError(xrv, &pat->re, "Unexpected regex error");
   1747        /* fall through */
   1748     case REG_NOMATCH:
   1749 	if (*wp) {
   1750 	    MAYBE_ADD_SPACE();
   1751 	    Buf_AddBytes(buf,strlen(wp),wp);
   1752 	}
   1753 	break;
   1754     }
   1755     return(addSpace||added);
   1756 }
   1757 #endif
   1758 
   1759 
   1760 
   1761 /*-
   1762  *-----------------------------------------------------------------------
   1763  * VarLoopExpand --
   1764  *	Implements the :@<temp>@<string>@ modifier of ODE make.
   1765  *	We set the temp variable named in pattern.lhs to word and expand
   1766  *	pattern.rhs storing the result in the passed buffer.
   1767  *
   1768  * Input:
   1769  *	word		Word to modify
   1770  *	addSpace	True if space should be added before
   1771  *			other characters
   1772  *	buf		Buffer for result
   1773  *	pattern		Datafor substitution
   1774  *
   1775  * Results:
   1776  *	TRUE if a space is needed before more characters are added.
   1777  *
   1778  * Side Effects:
   1779  *	None.
   1780  *
   1781  *-----------------------------------------------------------------------
   1782  */
   1783 static Boolean
   1784 VarLoopExpand(GNode *ctx MAKE_ATTR_UNUSED,
   1785 	      Var_Parse_State *vpstate MAKE_ATTR_UNUSED,
   1786 	      char *word, Boolean addSpace, Buffer *buf,
   1787 	      void *loopp)
   1788 {
   1789     VarLoop_t	*loop = (VarLoop_t *)loopp;
   1790     char *s;
   1791     int slen;
   1792 
   1793     if (word && *word) {
   1794         Var_Set(loop->tvar, word, loop->ctxt, VAR_NO_EXPORT);
   1795         s = Var_Subst(NULL, loop->str, loop->ctxt, loop->errnum);
   1796         if (s != NULL && *s != '\0') {
   1797             if (addSpace && *s != '\n')
   1798                 Buf_AddByte(buf, ' ');
   1799             Buf_AddBytes(buf, (slen = strlen(s)), s);
   1800             addSpace = (slen > 0 && s[slen - 1] != '\n');
   1801             free(s);
   1802         }
   1803     }
   1804     return addSpace;
   1805 }
   1806 
   1807 
   1808 /*-
   1809  *-----------------------------------------------------------------------
   1810  * VarSelectWords --
   1811  *	Implements the :[start..end] modifier.
   1812  *	This is a special case of VarModify since we want to be able
   1813  *	to scan the list backwards if start > end.
   1814  *
   1815  * Input:
   1816  *	str		String whose words should be trimmed
   1817  *	seldata		words to select
   1818  *
   1819  * Results:
   1820  *	A string of all the words selected.
   1821  *
   1822  * Side Effects:
   1823  *	None.
   1824  *
   1825  *-----------------------------------------------------------------------
   1826  */
   1827 static char *
   1828 VarSelectWords(GNode *ctx MAKE_ATTR_UNUSED, Var_Parse_State *vpstate,
   1829 	       const char *str, VarSelectWords_t *seldata)
   1830 {
   1831     Buffer  	  buf;		    /* Buffer for the new string */
   1832     Boolean 	  addSpace; 	    /* TRUE if need to add a space to the
   1833 				     * buffer before adding the trimmed
   1834 				     * word */
   1835     char **av;			    /* word list */
   1836     char *as;			    /* word list memory */
   1837     int ac, i;
   1838     int start, end, step;
   1839 
   1840     Buf_Init(&buf, 0);
   1841     addSpace = FALSE;
   1842 
   1843     if (vpstate->oneBigWord) {
   1844 	/* fake what brk_string() would do if there were only one word */
   1845 	ac = 1;
   1846     	av = bmake_malloc((ac + 1) * sizeof(char *));
   1847 	as = bmake_strdup(str);
   1848 	av[0] = as;
   1849 	av[1] = NULL;
   1850     } else {
   1851 	av = brk_string(str, &ac, FALSE, &as);
   1852     }
   1853 
   1854     /*
   1855      * Now sanitize seldata.
   1856      * If seldata->start or seldata->end are negative, convert them to
   1857      * the positive equivalents (-1 gets converted to argc, -2 gets
   1858      * converted to (argc-1), etc.).
   1859      */
   1860     if (seldata->start < 0)
   1861 	seldata->start = ac + seldata->start + 1;
   1862     if (seldata->end < 0)
   1863 	seldata->end = ac + seldata->end + 1;
   1864 
   1865     /*
   1866      * We avoid scanning more of the list than we need to.
   1867      */
   1868     if (seldata->start > seldata->end) {
   1869 	start = MIN(ac, seldata->start) - 1;
   1870 	end = MAX(0, seldata->end - 1);
   1871 	step = -1;
   1872     } else {
   1873 	start = MAX(0, seldata->start - 1);
   1874 	end = MIN(ac, seldata->end);
   1875 	step = 1;
   1876     }
   1877 
   1878     for (i = start;
   1879 	 (step < 0 && i >= end) || (step > 0 && i < end);
   1880 	 i += step) {
   1881 	if (av[i] && *av[i]) {
   1882 	    if (addSpace && vpstate->varSpace) {
   1883 		Buf_AddByte(&buf, vpstate->varSpace);
   1884 	    }
   1885 	    Buf_AddBytes(&buf, strlen(av[i]), av[i]);
   1886 	    addSpace = TRUE;
   1887 	}
   1888     }
   1889 
   1890     free(as);
   1891     free(av);
   1892 
   1893     return Buf_Destroy(&buf, FALSE);
   1894 }
   1895 
   1896 
   1897 /*-
   1898  * VarRealpath --
   1899  *	Replace each word with the result of realpath()
   1900  *	if successful.
   1901  */
   1902 static Boolean
   1903 VarRealpath(GNode *ctx MAKE_ATTR_UNUSED, Var_Parse_State *vpstate,
   1904 	    char *word, Boolean addSpace, Buffer *buf,
   1905 	    void *patternp MAKE_ATTR_UNUSED)
   1906 {
   1907 	struct stat st;
   1908 	char rbuf[MAXPATHLEN];
   1909 	char *rp;
   1910 
   1911 	if (addSpace && vpstate->varSpace) {
   1912 	    Buf_AddByte(buf, vpstate->varSpace);
   1913 	}
   1914 	addSpace = TRUE;
   1915 	rp = realpath(word, rbuf);
   1916 	if (rp && *rp == '/' && stat(rp, &st) == 0)
   1917 		word = rp;
   1918 
   1919 	Buf_AddBytes(buf, strlen(word), word);
   1920 	return(addSpace);
   1921 }
   1922 
   1923 /*-
   1924  *-----------------------------------------------------------------------
   1925  * VarModify --
   1926  *	Modify each of the words of the passed string using the given
   1927  *	function. Used to implement all modifiers.
   1928  *
   1929  * Input:
   1930  *	str		String whose words should be trimmed
   1931  *	modProc		Function to use to modify them
   1932  *	datum		Datum to pass it
   1933  *
   1934  * Results:
   1935  *	A string of all the words modified appropriately.
   1936  *
   1937  * Side Effects:
   1938  *	None.
   1939  *
   1940  *-----------------------------------------------------------------------
   1941  */
   1942 static char *
   1943 VarModify(GNode *ctx, Var_Parse_State *vpstate,
   1944     const char *str,
   1945     Boolean (*modProc)(GNode *, Var_Parse_State *, char *,
   1946 		       Boolean, Buffer *, void *),
   1947     void *datum)
   1948 {
   1949     Buffer  	  buf;		    /* Buffer for the new string */
   1950     Boolean 	  addSpace; 	    /* TRUE if need to add a space to the
   1951 				     * buffer before adding the trimmed
   1952 				     * word */
   1953     char **av;			    /* word list */
   1954     char *as;			    /* word list memory */
   1955     int ac, i;
   1956 
   1957     Buf_Init(&buf, 0);
   1958     addSpace = FALSE;
   1959 
   1960     if (vpstate->oneBigWord) {
   1961 	/* fake what brk_string() would do if there were only one word */
   1962 	ac = 1;
   1963     	av = bmake_malloc((ac + 1) * sizeof(char *));
   1964 	as = bmake_strdup(str);
   1965 	av[0] = as;
   1966 	av[1] = NULL;
   1967     } else {
   1968 	av = brk_string(str, &ac, FALSE, &as);
   1969     }
   1970 
   1971     for (i = 0; i < ac; i++) {
   1972 	addSpace = (*modProc)(ctx, vpstate, av[i], addSpace, &buf, datum);
   1973     }
   1974 
   1975     free(as);
   1976     free(av);
   1977 
   1978     return Buf_Destroy(&buf, FALSE);
   1979 }
   1980 
   1981 
   1982 static int
   1983 VarWordCompare(const void *a, const void *b)
   1984 {
   1985 	int r = strcmp(*(const char * const *)a, *(const char * const *)b);
   1986 	return r;
   1987 }
   1988 
   1989 /*-
   1990  *-----------------------------------------------------------------------
   1991  * VarOrder --
   1992  *	Order the words in the string.
   1993  *
   1994  * Input:
   1995  *	str		String whose words should be sorted.
   1996  *	otype		How to order: s - sort, x - random.
   1997  *
   1998  * Results:
   1999  *	A string containing the words ordered.
   2000  *
   2001  * Side Effects:
   2002  *	None.
   2003  *
   2004  *-----------------------------------------------------------------------
   2005  */
   2006 static char *
   2007 VarOrder(const char *str, const char otype)
   2008 {
   2009     Buffer  	  buf;		    /* Buffer for the new string */
   2010     char **av;			    /* word list [first word does not count] */
   2011     char *as;			    /* word list memory */
   2012     int ac, i;
   2013 
   2014     Buf_Init(&buf, 0);
   2015 
   2016     av = brk_string(str, &ac, FALSE, &as);
   2017 
   2018     if (ac > 0)
   2019 	switch (otype) {
   2020 	case 's':	/* sort alphabetically */
   2021 	    qsort(av, ac, sizeof(char *), VarWordCompare);
   2022 	    break;
   2023 	case 'x':	/* randomize */
   2024 	{
   2025 	    int rndidx;
   2026 	    char *t;
   2027 
   2028 	    /*
   2029 	     * We will use [ac..2] range for mod factors. This will produce
   2030 	     * random numbers in [(ac-1)..0] interval, and minimal
   2031 	     * reasonable value for mod factor is 2 (the mod 1 will produce
   2032 	     * 0 with probability 1).
   2033 	     */
   2034 	    for (i = ac-1; i > 0; i--) {
   2035 		rndidx = random() % (i + 1);
   2036 		if (i != rndidx) {
   2037 		    t = av[i];
   2038 		    av[i] = av[rndidx];
   2039 		    av[rndidx] = t;
   2040 		}
   2041 	    }
   2042 	}
   2043 	} /* end of switch */
   2044 
   2045     for (i = 0; i < ac; i++) {
   2046 	Buf_AddBytes(&buf, strlen(av[i]), av[i]);
   2047 	if (i != ac - 1)
   2048 	    Buf_AddByte(&buf, ' ');
   2049     }
   2050 
   2051     free(as);
   2052     free(av);
   2053 
   2054     return Buf_Destroy(&buf, FALSE);
   2055 }
   2056 
   2057 
   2058 /*-
   2059  *-----------------------------------------------------------------------
   2060  * VarUniq --
   2061  *	Remove adjacent duplicate words.
   2062  *
   2063  * Input:
   2064  *	str		String whose words should be sorted
   2065  *
   2066  * Results:
   2067  *	A string containing the resulting words.
   2068  *
   2069  * Side Effects:
   2070  *	None.
   2071  *
   2072  *-----------------------------------------------------------------------
   2073  */
   2074 static char *
   2075 VarUniq(const char *str)
   2076 {
   2077     Buffer	  buf;		    /* Buffer for new string */
   2078     char 	**av;		    /* List of words to affect */
   2079     char 	 *as;		    /* Word list memory */
   2080     int 	  ac, i, j;
   2081 
   2082     Buf_Init(&buf, 0);
   2083     av = brk_string(str, &ac, FALSE, &as);
   2084 
   2085     if (ac > 1) {
   2086 	for (j = 0, i = 1; i < ac; i++)
   2087 	    if (strcmp(av[i], av[j]) != 0 && (++j != i))
   2088 		av[j] = av[i];
   2089 	ac = j + 1;
   2090     }
   2091 
   2092     for (i = 0; i < ac; i++) {
   2093 	Buf_AddBytes(&buf, strlen(av[i]), av[i]);
   2094 	if (i != ac - 1)
   2095 	    Buf_AddByte(&buf, ' ');
   2096     }
   2097 
   2098     free(as);
   2099     free(av);
   2100 
   2101     return Buf_Destroy(&buf, FALSE);
   2102 }
   2103 
   2104 
   2105 /*-
   2106  *-----------------------------------------------------------------------
   2107  * VarGetPattern --
   2108  *	Pass through the tstr looking for 1) escaped delimiters,
   2109  *	'$'s and backslashes (place the escaped character in
   2110  *	uninterpreted) and 2) unescaped $'s that aren't before
   2111  *	the delimiter (expand the variable substitution unless flags
   2112  *	has VAR_NOSUBST set).
   2113  *	Return the expanded string or NULL if the delimiter was missing
   2114  *	If pattern is specified, handle escaped ampersands, and replace
   2115  *	unescaped ampersands with the lhs of the pattern.
   2116  *
   2117  * Results:
   2118  *	A string of all the words modified appropriately.
   2119  *	If length is specified, return the string length of the buffer
   2120  *	If flags is specified and the last character of the pattern is a
   2121  *	$ set the VAR_MATCH_END bit of flags.
   2122  *
   2123  * Side Effects:
   2124  *	None.
   2125  *-----------------------------------------------------------------------
   2126  */
   2127 static char *
   2128 VarGetPattern(GNode *ctxt, Var_Parse_State *vpstate MAKE_ATTR_UNUSED,
   2129 	      int errnum, const char **tstr, int delim, int *flags,
   2130 	      int *length, VarPattern *pattern)
   2131 {
   2132     const char *cp;
   2133     char *rstr;
   2134     Buffer buf;
   2135     int junk;
   2136 
   2137     Buf_Init(&buf, 0);
   2138     if (length == NULL)
   2139 	length = &junk;
   2140 
   2141 #define IS_A_MATCH(cp, delim) \
   2142     ((cp[0] == '\\') && ((cp[1] == delim) ||  \
   2143      (cp[1] == '\\') || (cp[1] == '$') || (pattern && (cp[1] == '&'))))
   2144 
   2145     /*
   2146      * Skim through until the matching delimiter is found;
   2147      * pick up variable substitutions on the way. Also allow
   2148      * backslashes to quote the delimiter, $, and \, but don't
   2149      * touch other backslashes.
   2150      */
   2151     for (cp = *tstr; *cp && (*cp != delim); cp++) {
   2152 	if (IS_A_MATCH(cp, delim)) {
   2153 	    Buf_AddByte(&buf, cp[1]);
   2154 	    cp++;
   2155 	} else if (*cp == '$') {
   2156 	    if (cp[1] == delim) {
   2157 		if (flags == NULL)
   2158 		    Buf_AddByte(&buf, *cp);
   2159 		else
   2160 		    /*
   2161 		     * Unescaped $ at end of pattern => anchor
   2162 		     * pattern at end.
   2163 		     */
   2164 		    *flags |= VAR_MATCH_END;
   2165 	    } else {
   2166 		if (flags == NULL || (*flags & VAR_NOSUBST) == 0) {
   2167 		    char   *cp2;
   2168 		    int     len;
   2169 		    void   *freeIt;
   2170 
   2171 		    /*
   2172 		     * If unescaped dollar sign not before the
   2173 		     * delimiter, assume it's a variable
   2174 		     * substitution and recurse.
   2175 		     */
   2176 		    cp2 = Var_Parse(cp, ctxt, errnum, &len, &freeIt);
   2177 		    Buf_AddBytes(&buf, strlen(cp2), cp2);
   2178 		    if (freeIt)
   2179 			free(freeIt);
   2180 		    cp += len - 1;
   2181 		} else {
   2182 		    const char *cp2 = &cp[1];
   2183 
   2184 		    if (*cp2 == PROPEN || *cp2 == BROPEN) {
   2185 			/*
   2186 			 * Find the end of this variable reference
   2187 			 * and suck it in without further ado.
   2188 			 * It will be interperated later.
   2189 			 */
   2190 			int have = *cp2;
   2191 			int want = (*cp2 == PROPEN) ? PRCLOSE : BRCLOSE;
   2192 			int depth = 1;
   2193 
   2194 			for (++cp2; *cp2 != '\0' && depth > 0; ++cp2) {
   2195 			    if (cp2[-1] != '\\') {
   2196 				if (*cp2 == have)
   2197 				    ++depth;
   2198 				if (*cp2 == want)
   2199 				    --depth;
   2200 			    }
   2201 			}
   2202 			Buf_AddBytes(&buf, cp2 - cp, cp);
   2203 			cp = --cp2;
   2204 		    } else
   2205 			Buf_AddByte(&buf, *cp);
   2206 		}
   2207 	    }
   2208 	}
   2209 	else if (pattern && *cp == '&')
   2210 	    Buf_AddBytes(&buf, pattern->leftLen, pattern->lhs);
   2211 	else
   2212 	    Buf_AddByte(&buf, *cp);
   2213     }
   2214 
   2215     if (*cp != delim) {
   2216 	*tstr = cp;
   2217 	*length = 0;
   2218 	return NULL;
   2219     }
   2220 
   2221     *tstr = ++cp;
   2222     *length = Buf_Size(&buf);
   2223     rstr = Buf_Destroy(&buf, FALSE);
   2224     if (DEBUG(VAR))
   2225 	fprintf(debug_file, "Modifier pattern: \"%s\"\n", rstr);
   2226     return rstr;
   2227 }
   2228 
   2229 /*-
   2230  *-----------------------------------------------------------------------
   2231  * VarQuote --
   2232  *	Quote shell meta-characters in the string
   2233  *
   2234  * Results:
   2235  *	The quoted string
   2236  *
   2237  * Side Effects:
   2238  *	None.
   2239  *
   2240  *-----------------------------------------------------------------------
   2241  */
   2242 static char *
   2243 VarQuote(char *str)
   2244 {
   2245 
   2246     Buffer  	  buf;
   2247     /* This should cover most shells :-( */
   2248     static const char meta[] = "\n \t'`\";&<>()|*?{}[]\\$!#^~";
   2249     const char	*newline;
   2250     size_t len, nlen;
   2251 
   2252     if ((newline = Shell_GetNewline()) == NULL)
   2253 	    newline = "\\\n";
   2254     nlen = strlen(newline);
   2255 
   2256     Buf_Init(&buf, 0);
   2257     while (*str != '\0') {
   2258 	if ((len = strcspn(str, meta)) != 0) {
   2259 	    Buf_AddBytes(&buf, len, str);
   2260 	    str += len;
   2261 	} else if (*str == '\n') {
   2262 	    Buf_AddBytes(&buf, nlen, newline);
   2263 	    ++str;
   2264 	} else {
   2265 	    Buf_AddByte(&buf, '\\');
   2266 	    Buf_AddByte(&buf, *str);
   2267 	    ++str;
   2268 	}
   2269     }
   2270     str = Buf_Destroy(&buf, FALSE);
   2271     if (DEBUG(VAR))
   2272 	fprintf(debug_file, "QuoteMeta: [%s]\n", str);
   2273     return str;
   2274 }
   2275 
   2276 /*-
   2277  *-----------------------------------------------------------------------
   2278  * VarHash --
   2279  *      Hash the string using the MurmurHash3 algorithm.
   2280  *      Output is computed using 32bit Little Endian arithmetic.
   2281  *
   2282  * Input:
   2283  *	str		String to modify
   2284  *
   2285  * Results:
   2286  *      Hash value of str, encoded as 8 hex digits.
   2287  *
   2288  * Side Effects:
   2289  *      None.
   2290  *
   2291  *-----------------------------------------------------------------------
   2292  */
   2293 static char *
   2294 VarHash(char *str)
   2295 {
   2296     static const char    hexdigits[16] = "0123456789abcdef";
   2297     Buffer         buf;
   2298     size_t         len, len2;
   2299     unsigned char  *ustr = (unsigned char *)str;
   2300     uint32_t       h, k, c1, c2;
   2301 
   2302     h  = 0x971e137bU;
   2303     c1 = 0x95543787U;
   2304     c2 = 0x2ad7eb25U;
   2305     len2 = strlen(str);
   2306 
   2307     for (len = len2; len; ) {
   2308 	k = 0;
   2309 	switch (len) {
   2310 	default:
   2311 	    k = (ustr[3] << 24) | (ustr[2] << 16) | (ustr[1] << 8) | ustr[0];
   2312 	    len -= 4;
   2313 	    ustr += 4;
   2314 	    break;
   2315 	case 3:
   2316 	    k |= (ustr[2] << 16);
   2317 	case 2:
   2318 	    k |= (ustr[1] << 8);
   2319 	case 1:
   2320 	    k |= ustr[0];
   2321 	    len = 0;
   2322 	}
   2323 	c1 = c1 * 5 + 0x7b7d159cU;
   2324 	c2 = c2 * 5 + 0x6bce6396U;
   2325 	k *= c1;
   2326 	k = (k << 11) ^ (k >> 21);
   2327 	k *= c2;
   2328 	h = (h << 13) ^ (h >> 19);
   2329 	h = h * 5 + 0x52dce729U;
   2330 	h ^= k;
   2331    }
   2332    h ^= len2;
   2333    h *= 0x85ebca6b;
   2334    h ^= h >> 13;
   2335    h *= 0xc2b2ae35;
   2336    h ^= h >> 16;
   2337 
   2338    Buf_Init(&buf, 0);
   2339    for (len = 0; len < 8; ++len) {
   2340        Buf_AddByte(&buf, hexdigits[h & 15]);
   2341        h >>= 4;
   2342    }
   2343 
   2344    return Buf_Destroy(&buf, FALSE);
   2345 }
   2346 
   2347 static char *
   2348 VarStrftime(const char *fmt, int zulu)
   2349 {
   2350     char buf[BUFSIZ];
   2351     time_t utc;
   2352 
   2353     time(&utc);
   2354     if (!*fmt)
   2355 	fmt = "%c";
   2356     strftime(buf, sizeof(buf), fmt, zulu ? gmtime(&utc) : localtime(&utc));
   2357 
   2358     buf[sizeof(buf) - 1] = '\0';
   2359     return bmake_strdup(buf);
   2360 }
   2361 
   2362 /*
   2363  * Now we need to apply any modifiers the user wants applied.
   2364  * These are:
   2365  *  	  :M<pattern>	words which match the given <pattern>.
   2366  *  			<pattern> is of the standard file
   2367  *  			wildcarding form.
   2368  *  	  :N<pattern>	words which do not match the given <pattern>.
   2369  *  	  :S<d><pat1><d><pat2><d>[1gW]
   2370  *  			Substitute <pat2> for <pat1> in the value
   2371  *  	  :C<d><pat1><d><pat2><d>[1gW]
   2372  *  			Substitute <pat2> for regex <pat1> in the value
   2373  *  	  :H		Substitute the head of each word
   2374  *  	  :T		Substitute the tail of each word
   2375  *  	  :E		Substitute the extension (minus '.') of
   2376  *  			each word
   2377  *  	  :R		Substitute the root of each word
   2378  *  			(pathname minus the suffix).
   2379  *	  :O		("Order") Alphabeticaly sort words in variable.
   2380  *	  :Ox		("intermiX") Randomize words in variable.
   2381  *	  :u		("uniq") Remove adjacent duplicate words.
   2382  *	  :tu		Converts the variable contents to uppercase.
   2383  *	  :tl		Converts the variable contents to lowercase.
   2384  *	  :ts[c]	Sets varSpace - the char used to
   2385  *			separate words to 'c'. If 'c' is
   2386  *			omitted then no separation is used.
   2387  *	  :tW		Treat the variable contents as a single
   2388  *			word, even if it contains spaces.
   2389  *			(Mnemonic: one big 'W'ord.)
   2390  *	  :tw		Treat the variable contents as multiple
   2391  *			space-separated words.
   2392  *			(Mnemonic: many small 'w'ords.)
   2393  *	  :[index]	Select a single word from the value.
   2394  *	  :[start..end]	Select multiple words from the value.
   2395  *	  :[*] or :[0]	Select the entire value, as a single
   2396  *			word.  Equivalent to :tW.
   2397  *	  :[@]		Select the entire value, as multiple
   2398  *			words.	Undoes the effect of :[*].
   2399  *			Equivalent to :tw.
   2400  *	  :[#]		Returns the number of words in the value.
   2401  *
   2402  *	  :?<true-value>:<false-value>
   2403  *			If the variable evaluates to true, return
   2404  *			true value, else return the second value.
   2405  *    	  :lhs=rhs  	Like :S, but the rhs goes to the end of
   2406  *    			the invocation.
   2407  *	  :sh		Treat the current value as a command
   2408  *			to be run, new value is its output.
   2409  * The following added so we can handle ODE makefiles.
   2410  *	  :@<tmpvar>@<newval>@
   2411  *			Assign a temporary local variable <tmpvar>
   2412  *			to the current value of each word in turn
   2413  *			and replace each word with the result of
   2414  *			evaluating <newval>
   2415  *	  :D<newval>	Use <newval> as value if variable defined
   2416  *	  :U<newval>	Use <newval> as value if variable undefined
   2417  *	  :L		Use the name of the variable as the value.
   2418  *	  :P		Use the path of the node that has the same
   2419  *			name as the variable as the value.  This
   2420  *			basically includes an implied :L so that
   2421  *			the common method of refering to the path
   2422  *			of your dependent 'x' in a rule is to use
   2423  *			the form '${x:P}'.
   2424  *	  :!<cmd>!	Run cmd much the same as :sh run's the
   2425  *			current value of the variable.
   2426  * The ::= modifiers, actually assign a value to the variable.
   2427  * Their main purpose is in supporting modifiers of .for loop
   2428  * iterators and other obscure uses.  They always expand to
   2429  * nothing.  In a target rule that would otherwise expand to an
   2430  * empty line they can be preceded with @: to keep make happy.
   2431  * Eg.
   2432  *
   2433  * foo:	.USE
   2434  * .for i in ${.TARGET} ${.TARGET:R}.gz
   2435  * 	@: ${t::=$i}
   2436  *	@echo blah ${t:T}
   2437  * .endfor
   2438  *
   2439  *	  ::=<str>	Assigns <str> as the new value of variable.
   2440  *	  ::?=<str>	Assigns <str> as value of variable if
   2441  *			it was not already set.
   2442  *	  ::+=<str>	Appends <str> to variable.
   2443  *	  ::!=<cmd>	Assigns output of <cmd> as the new value of
   2444  *			variable.
   2445  */
   2446 
   2447 /* we now have some modifiers with long names */
   2448 #define STRMOD_MATCH(s, want, n) \
   2449     (strncmp(s, want, n) == 0 && (s[n] == endc || s[n] == ':'))
   2450 
   2451 static char *
   2452 ApplyModifiers(char *nstr, const char *tstr,
   2453 	       int startc, int endc,
   2454 	       Var *v, GNode *ctxt, Boolean errnum,
   2455 	       int *lengthPtr, void **freePtr)
   2456 {
   2457     const char 	   *start;
   2458     const char     *cp;    	/* Secondary pointer into str (place marker
   2459 				 * for tstr) */
   2460     char	   *newStr;	/* New value to return */
   2461     char	    termc;	/* Character which terminated scan */
   2462     int             cnt;	/* Used to count brace pairs when variable in
   2463 				 * in parens or braces */
   2464     char	delim;
   2465     int		modifier;	/* that we are processing */
   2466     Var_Parse_State parsestate; /* Flags passed to helper functions */
   2467 
   2468     delim = '\0';
   2469     parsestate.oneBigWord = FALSE;
   2470     parsestate.varSpace = ' ';	/* word separator */
   2471 
   2472     start = cp = tstr;
   2473 
   2474     while (*tstr && *tstr != endc) {
   2475 
   2476 	if (*tstr == '$') {
   2477 	    /*
   2478 	     * We may have some complex modifiers in a variable.
   2479 	     */
   2480 	    void *freeIt;
   2481 	    char *rval;
   2482 	    int rlen;
   2483 	    int c;
   2484 
   2485 	    rval = Var_Parse(tstr, ctxt, errnum, &rlen, &freeIt);
   2486 
   2487 	    /*
   2488 	     * If we have not parsed up to endc or ':',
   2489 	     * we are not interested.
   2490 	     */
   2491 	    if (rval != NULL && *rval &&
   2492 		(c = tstr[rlen]) != '\0' &&
   2493 		c != ':' &&
   2494 		c != endc) {
   2495 		if (freeIt)
   2496 		    free(freeIt);
   2497 		goto apply_mods;
   2498 	    }
   2499 
   2500 	    if (DEBUG(VAR)) {
   2501 		fprintf(debug_file, "Got '%s' from '%.*s'%.*s\n",
   2502 		       rval, rlen, tstr, rlen, tstr + rlen);
   2503 	    }
   2504 
   2505 	    tstr += rlen;
   2506 
   2507 	    if (rval != NULL && *rval) {
   2508 		int used;
   2509 
   2510 		nstr = ApplyModifiers(nstr, rval,
   2511 				      0, 0,
   2512 				      v, ctxt, errnum, &used, freePtr);
   2513 		if (nstr == var_Error
   2514 		    || (nstr == varNoError && errnum == 0)
   2515 		    || strlen(rval) != (size_t) used) {
   2516 		    if (freeIt)
   2517 			free(freeIt);
   2518 		    goto out;		/* error already reported */
   2519 		}
   2520 	    }
   2521 	    if (freeIt)
   2522 		free(freeIt);
   2523 	    if (*tstr == ':')
   2524 		tstr++;
   2525 	    else if (!*tstr && endc) {
   2526 		Error("Unclosed variable specification after complex modifier (expecting '%c') for %s", endc, v->name);
   2527 		goto out;
   2528 	    }
   2529 	    continue;
   2530 	}
   2531     apply_mods:
   2532 	if (DEBUG(VAR)) {
   2533 	    fprintf(debug_file, "Applying[%s] :%c to \"%s\"\n", v->name,
   2534 		*tstr, nstr);
   2535 	}
   2536 	newStr = var_Error;
   2537 	switch ((modifier = *tstr)) {
   2538 	case ':':
   2539 	    {
   2540 		if (tstr[1] == '=' ||
   2541 		    (tstr[2] == '=' &&
   2542 		     (tstr[1] == '!' || tstr[1] == '+' || tstr[1] == '?'))) {
   2543 		    /*
   2544 		     * "::=", "::!=", "::+=", or "::?="
   2545 		     */
   2546 		    GNode *v_ctxt;		/* context where v belongs */
   2547 		    const char *emsg;
   2548 		    char *sv_name;
   2549 		    VarPattern	pattern;
   2550 		    int	how;
   2551 
   2552 		    if (v->name[0] == 0)
   2553 			goto bad_modifier;
   2554 
   2555 		    v_ctxt = ctxt;
   2556 		    sv_name = NULL;
   2557 		    ++tstr;
   2558 		    if (v->flags & VAR_JUNK) {
   2559 			/*
   2560 			 * We need to bmake_strdup() it incase
   2561 			 * VarGetPattern() recurses.
   2562 			 */
   2563 			sv_name = v->name;
   2564 			v->name = bmake_strdup(v->name);
   2565 		    } else if (ctxt != VAR_GLOBAL) {
   2566 			Var *gv = VarFind(v->name, ctxt, 0);
   2567 			if (gv == NULL)
   2568 			    v_ctxt = VAR_GLOBAL;
   2569 			else
   2570 			    VarFreeEnv(gv, TRUE);
   2571 		    }
   2572 
   2573 		    switch ((how = *tstr)) {
   2574 		    case '+':
   2575 		    case '?':
   2576 		    case '!':
   2577 			cp = &tstr[2];
   2578 			break;
   2579 		    default:
   2580 			cp = ++tstr;
   2581 			break;
   2582 		    }
   2583 		    delim = startc == PROPEN ? PRCLOSE : BRCLOSE;
   2584 		    pattern.flags = 0;
   2585 
   2586 		    pattern.rhs = VarGetPattern(ctxt, &parsestate, errnum,
   2587 						&cp, delim, NULL,
   2588 						&pattern.rightLen,
   2589 						NULL);
   2590 		    if (v->flags & VAR_JUNK) {
   2591 			/* restore original name */
   2592 			free(v->name);
   2593 			v->name = sv_name;
   2594 		    }
   2595 		    if (pattern.rhs == NULL)
   2596 			goto cleanup;
   2597 
   2598 		    termc = *--cp;
   2599 		    delim = '\0';
   2600 
   2601 		    switch (how) {
   2602 		    case '+':
   2603 			Var_Append(v->name, pattern.rhs, v_ctxt);
   2604 			break;
   2605 		    case '!':
   2606 			newStr = Cmd_Exec(pattern.rhs, &emsg);
   2607 			if (emsg)
   2608 			    Error(emsg, nstr);
   2609 			else
   2610 			    Var_Set(v->name, newStr,  v_ctxt, 0);
   2611 			if (newStr)
   2612 			    free(newStr);
   2613 			break;
   2614 		    case '?':
   2615 			if ((v->flags & VAR_JUNK) == 0)
   2616 			    break;
   2617 			/* FALLTHROUGH */
   2618 		    default:
   2619 			Var_Set(v->name, pattern.rhs, v_ctxt, 0);
   2620 			break;
   2621 		    }
   2622 		    free(UNCONST(pattern.rhs));
   2623 		    newStr = var_Error;
   2624 		    break;
   2625 		}
   2626 		goto default_case; /* "::<unrecognised>" */
   2627 	    }
   2628 	case '@':
   2629 	    {
   2630 		VarLoop_t	loop;
   2631 		int flags = VAR_NOSUBST;
   2632 
   2633 		cp = ++tstr;
   2634 		delim = '@';
   2635 		if ((loop.tvar = VarGetPattern(ctxt, &parsestate, errnum,
   2636 					       &cp, delim,
   2637 					       &flags, &loop.tvarLen,
   2638 					       NULL)) == NULL)
   2639 		    goto cleanup;
   2640 
   2641 		if ((loop.str = VarGetPattern(ctxt, &parsestate, errnum,
   2642 					      &cp, delim,
   2643 					      &flags, &loop.strLen,
   2644 					      NULL)) == NULL)
   2645 		    goto cleanup;
   2646 
   2647 		termc = *cp;
   2648 		delim = '\0';
   2649 
   2650 		loop.errnum = errnum;
   2651 		loop.ctxt = ctxt;
   2652 		newStr = VarModify(ctxt, &parsestate, nstr, VarLoopExpand,
   2653 				   &loop);
   2654 		free(loop.tvar);
   2655 		free(loop.str);
   2656 		break;
   2657 	    }
   2658 	case 'D':
   2659 	case 'U':
   2660 	    {
   2661 		Buffer  buf;    	/* Buffer for patterns */
   2662 		int	    wantit;	/* want data in buffer */
   2663 
   2664 		/*
   2665 		 * Pass through tstr looking for 1) escaped delimiters,
   2666 		 * '$'s and backslashes (place the escaped character in
   2667 		 * uninterpreted) and 2) unescaped $'s that aren't before
   2668 		 * the delimiter (expand the variable substitution).
   2669 		 * The result is left in the Buffer buf.
   2670 		 */
   2671 		Buf_Init(&buf, 0);
   2672 		for (cp = tstr + 1;
   2673 		     *cp != endc && *cp != ':' && *cp != '\0';
   2674 		     cp++) {
   2675 		    if ((*cp == '\\') &&
   2676 			((cp[1] == ':') ||
   2677 			 (cp[1] == '$') ||
   2678 			 (cp[1] == endc) ||
   2679 			 (cp[1] == '\\')))
   2680 			{
   2681 			    Buf_AddByte(&buf, cp[1]);
   2682 			    cp++;
   2683 			} else if (*cp == '$') {
   2684 			    /*
   2685 			     * If unescaped dollar sign, assume it's a
   2686 			     * variable substitution and recurse.
   2687 			     */
   2688 			    char    *cp2;
   2689 			    int	    len;
   2690 			    void    *freeIt;
   2691 
   2692 			    cp2 = Var_Parse(cp, ctxt, errnum, &len, &freeIt);
   2693 			    Buf_AddBytes(&buf, strlen(cp2), cp2);
   2694 			    if (freeIt)
   2695 				free(freeIt);
   2696 			    cp += len - 1;
   2697 			} else {
   2698 			    Buf_AddByte(&buf, *cp);
   2699 			}
   2700 		}
   2701 
   2702 		termc = *cp;
   2703 
   2704 		if (*tstr == 'U')
   2705 		    wantit = ((v->flags & VAR_JUNK) != 0);
   2706 		else
   2707 		    wantit = ((v->flags & VAR_JUNK) == 0);
   2708 		if ((v->flags & VAR_JUNK) != 0)
   2709 		    v->flags |= VAR_KEEP;
   2710 		if (wantit) {
   2711 		    newStr = Buf_Destroy(&buf, FALSE);
   2712 		} else {
   2713 		    newStr = nstr;
   2714 		    Buf_Destroy(&buf, TRUE);
   2715 		}
   2716 		break;
   2717 	    }
   2718 	case 'L':
   2719 	    {
   2720 		if ((v->flags & VAR_JUNK) != 0)
   2721 		    v->flags |= VAR_KEEP;
   2722 		newStr = bmake_strdup(v->name);
   2723 		cp = ++tstr;
   2724 		termc = *tstr;
   2725 		break;
   2726 	    }
   2727 	case 'P':
   2728 	    {
   2729 		GNode *gn;
   2730 
   2731 		if ((v->flags & VAR_JUNK) != 0)
   2732 		    v->flags |= VAR_KEEP;
   2733 		gn = Targ_FindNode(v->name, TARG_NOCREATE);
   2734 		if (gn == NULL || gn->type & OP_NOPATH) {
   2735 		    newStr = NULL;
   2736 		} else if (gn->path) {
   2737 		    newStr = bmake_strdup(gn->path);
   2738 		} else {
   2739 		    newStr = Dir_FindFile(v->name, Suff_FindPath(gn));
   2740 		}
   2741 		if (!newStr) {
   2742 		    newStr = bmake_strdup(v->name);
   2743 		}
   2744 		cp = ++tstr;
   2745 		termc = *tstr;
   2746 		break;
   2747 	    }
   2748 	case '!':
   2749 	    {
   2750 		const char *emsg;
   2751 		VarPattern 	    pattern;
   2752 		pattern.flags = 0;
   2753 
   2754 		delim = '!';
   2755 
   2756 		cp = ++tstr;
   2757 		if ((pattern.rhs = VarGetPattern(ctxt, &parsestate, errnum,
   2758 						 &cp, delim,
   2759 						 NULL, &pattern.rightLen,
   2760 						 NULL)) == NULL)
   2761 		    goto cleanup;
   2762 		newStr = Cmd_Exec(pattern.rhs, &emsg);
   2763 		free(UNCONST(pattern.rhs));
   2764 		if (emsg)
   2765 		    Error(emsg, nstr);
   2766 		termc = *cp;
   2767 		delim = '\0';
   2768 		if (v->flags & VAR_JUNK) {
   2769 		    v->flags |= VAR_KEEP;
   2770 		}
   2771 		break;
   2772 	    }
   2773 	case '[':
   2774 	    {
   2775 		/*
   2776 		 * Look for the closing ']', recursively
   2777 		 * expanding any embedded variables.
   2778 		 *
   2779 		 * estr is a pointer to the expanded result,
   2780 		 * which we must free().
   2781 		 */
   2782 		char *estr;
   2783 
   2784 		cp = tstr+1; /* point to char after '[' */
   2785 		delim = ']'; /* look for closing ']' */
   2786 		estr = VarGetPattern(ctxt, &parsestate,
   2787 				     errnum, &cp, delim,
   2788 				     NULL, NULL, NULL);
   2789 		if (estr == NULL)
   2790 		    goto cleanup; /* report missing ']' */
   2791 		/* now cp points just after the closing ']' */
   2792 		delim = '\0';
   2793 		if (cp[0] != ':' && cp[0] != endc) {
   2794 		    /* Found junk after ']' */
   2795 		    free(estr);
   2796 		    goto bad_modifier;
   2797 		}
   2798 		if (estr[0] == '\0') {
   2799 		    /* Found empty square brackets in ":[]". */
   2800 		    free(estr);
   2801 		    goto bad_modifier;
   2802 		} else if (estr[0] == '#' && estr[1] == '\0') {
   2803 		    /* Found ":[#]" */
   2804 
   2805 		    /*
   2806 		     * We will need enough space for the decimal
   2807 		     * representation of an int.  We calculate the
   2808 		     * space needed for the octal representation,
   2809 		     * and add enough slop to cope with a '-' sign
   2810 		     * (which should never be needed) and a '\0'
   2811 		     * string terminator.
   2812 		     */
   2813 		    int newStrSize =
   2814 			(sizeof(int) * CHAR_BIT + 2) / 3 + 2;
   2815 
   2816 		    newStr = bmake_malloc(newStrSize);
   2817 		    if (parsestate.oneBigWord) {
   2818 			strncpy(newStr, "1", newStrSize);
   2819 		    } else {
   2820 			/* XXX: brk_string() is a rather expensive
   2821 			 * way of counting words. */
   2822 			char **av;
   2823 			char *as;
   2824 			int ac;
   2825 
   2826 			av = brk_string(nstr, &ac, FALSE, &as);
   2827 			snprintf(newStr, newStrSize,  "%d", ac);
   2828 			free(as);
   2829 			free(av);
   2830 		    }
   2831 		    termc = *cp;
   2832 		    free(estr);
   2833 		    break;
   2834 		} else if (estr[0] == '*' && estr[1] == '\0') {
   2835 		    /* Found ":[*]" */
   2836 		    parsestate.oneBigWord = TRUE;
   2837 		    newStr = nstr;
   2838 		    termc = *cp;
   2839 		    free(estr);
   2840 		    break;
   2841 		} else if (estr[0] == '@' && estr[1] == '\0') {
   2842 		    /* Found ":[@]" */
   2843 		    parsestate.oneBigWord = FALSE;
   2844 		    newStr = nstr;
   2845 		    termc = *cp;
   2846 		    free(estr);
   2847 		    break;
   2848 		} else {
   2849 		    /*
   2850 		     * We expect estr to contain a single
   2851 		     * integer for :[N], or two integers
   2852 		     * separated by ".." for :[start..end].
   2853 		     */
   2854 		    char *ep;
   2855 
   2856 		    VarSelectWords_t seldata = { 0, 0 };
   2857 
   2858 		    seldata.start = strtol(estr, &ep, 0);
   2859 		    if (ep == estr) {
   2860 			/* Found junk instead of a number */
   2861 			free(estr);
   2862 			goto bad_modifier;
   2863 		    } else if (ep[0] == '\0') {
   2864 			/* Found only one integer in :[N] */
   2865 			seldata.end = seldata.start;
   2866 		    } else if (ep[0] == '.' && ep[1] == '.' &&
   2867 			       ep[2] != '\0') {
   2868 			/* Expecting another integer after ".." */
   2869 			ep += 2;
   2870 			seldata.end = strtol(ep, &ep, 0);
   2871 			if (ep[0] != '\0') {
   2872 			    /* Found junk after ".." */
   2873 			    free(estr);
   2874 			    goto bad_modifier;
   2875 			}
   2876 		    } else {
   2877 			/* Found junk instead of ".." */
   2878 			free(estr);
   2879 			goto bad_modifier;
   2880 		    }
   2881 		    /*
   2882 		     * Now seldata is properly filled in,
   2883 		     * but we still have to check for 0 as
   2884 		     * a special case.
   2885 		     */
   2886 		    if (seldata.start == 0 && seldata.end == 0) {
   2887 			/* ":[0]" or perhaps ":[0..0]" */
   2888 			parsestate.oneBigWord = TRUE;
   2889 			newStr = nstr;
   2890 			termc = *cp;
   2891 			free(estr);
   2892 			break;
   2893 		    } else if (seldata.start == 0 ||
   2894 			       seldata.end == 0) {
   2895 			/* ":[0..N]" or ":[N..0]" */
   2896 			free(estr);
   2897 			goto bad_modifier;
   2898 		    }
   2899 		    /*
   2900 		     * Normal case: select the words
   2901 		     * described by seldata.
   2902 		     */
   2903 		    newStr = VarSelectWords(ctxt, &parsestate,
   2904 					    nstr, &seldata);
   2905 
   2906 		    termc = *cp;
   2907 		    free(estr);
   2908 		    break;
   2909 		}
   2910 
   2911 	    }
   2912 	case 'g':
   2913 	    cp = tstr + 1;	/* make sure it is set */
   2914 	    if (STRMOD_MATCH(tstr, "gmtime", 6)) {
   2915 		newStr = VarStrftime(nstr, 1);
   2916 		cp = tstr + 6;
   2917 		termc = *cp;
   2918 	    } else {
   2919 		goto default_case;
   2920 	    }
   2921 	    break;
   2922 	case 'h':
   2923 	    cp = tstr + 1;	/* make sure it is set */
   2924 	    if (STRMOD_MATCH(tstr, "hash", 4)) {
   2925 		newStr = VarHash(nstr);
   2926 		cp = tstr + 4;
   2927 		termc = *cp;
   2928 	    } else {
   2929 		goto default_case;
   2930 	    }
   2931 	    break;
   2932 	case 'l':
   2933 	    cp = tstr + 1;	/* make sure it is set */
   2934 	    if (STRMOD_MATCH(tstr, "localtime", 9)) {
   2935 		newStr = VarStrftime(nstr, 0);
   2936 		cp = tstr + 9;
   2937 		termc = *cp;
   2938 	    } else {
   2939 		goto default_case;
   2940 	    }
   2941 	    break;
   2942 	case 't':
   2943 	    {
   2944 		cp = tstr + 1;	/* make sure it is set */
   2945 		if (tstr[1] != endc && tstr[1] != ':') {
   2946 		    if (tstr[1] == 's') {
   2947 			/*
   2948 			 * Use the char (if any) at tstr[2]
   2949 			 * as the word separator.
   2950 			 */
   2951 			VarPattern pattern;
   2952 
   2953 			if (tstr[2] != endc &&
   2954 			    (tstr[3] == endc || tstr[3] == ':')) {
   2955 			    /* ":ts<unrecognised><endc>" or
   2956 			     * ":ts<unrecognised>:" */
   2957 			    parsestate.varSpace = tstr[2];
   2958 			    cp = tstr + 3;
   2959 			} else if (tstr[2] == endc || tstr[2] == ':') {
   2960 			    /* ":ts<endc>" or ":ts:" */
   2961 			    parsestate.varSpace = 0; /* no separator */
   2962 			    cp = tstr + 2;
   2963 			} else if (tstr[2] == '\\') {
   2964 			    switch (tstr[3]) {
   2965 			    case 'n':
   2966 				parsestate.varSpace = '\n';
   2967 				cp = tstr + 4;
   2968 				break;
   2969 			    case 't':
   2970 				parsestate.varSpace = '\t';
   2971 				cp = tstr + 4;
   2972 				break;
   2973 			    default:
   2974 				if (isdigit((unsigned char)tstr[3])) {
   2975 				    char *ep;
   2976 
   2977 				    parsestate.varSpace =
   2978 					strtoul(&tstr[3], &ep, 0);
   2979 				    if (*ep != ':' && *ep != endc)
   2980 					goto bad_modifier;
   2981 				    cp = ep;
   2982 				} else {
   2983 				    /*
   2984 				     * ":ts<backslash><unrecognised>".
   2985 				     */
   2986 				    goto bad_modifier;
   2987 				}
   2988 				break;
   2989 			    }
   2990 			} else {
   2991 			    /*
   2992 			     * Found ":ts<unrecognised><unrecognised>".
   2993 			     */
   2994 			    goto bad_modifier;
   2995 			}
   2996 
   2997 			termc = *cp;
   2998 
   2999 			/*
   3000 			 * We cannot be certain that VarModify
   3001 			 * will be used - even if there is a
   3002 			 * subsequent modifier, so do a no-op
   3003 			 * VarSubstitute now to for str to be
   3004 			 * re-expanded without the spaces.
   3005 			 */
   3006 			pattern.flags = VAR_SUB_ONE;
   3007 			pattern.lhs = pattern.rhs = "\032";
   3008 			pattern.leftLen = pattern.rightLen = 1;
   3009 
   3010 			newStr = VarModify(ctxt, &parsestate, nstr,
   3011 					   VarSubstitute,
   3012 					   &pattern);
   3013 		    } else if (tstr[2] == endc || tstr[2] == ':') {
   3014 			/*
   3015 			 * Check for two-character options:
   3016 			 * ":tu", ":tl"
   3017 			 */
   3018 			if (tstr[1] == 'A') { /* absolute path */
   3019 			    newStr = VarModify(ctxt, &parsestate, nstr,
   3020 					       VarRealpath, NULL);
   3021 			    cp = tstr + 2;
   3022 			    termc = *cp;
   3023 			} else if (tstr[1] == 'u') {
   3024 			    char *dp = bmake_strdup(nstr);
   3025 			    for (newStr = dp; *dp; dp++)
   3026 				*dp = toupper((unsigned char)*dp);
   3027 			    cp = tstr + 2;
   3028 			    termc = *cp;
   3029 			} else if (tstr[1] == 'l') {
   3030 			    char *dp = bmake_strdup(nstr);
   3031 			    for (newStr = dp; *dp; dp++)
   3032 				*dp = tolower((unsigned char)*dp);
   3033 			    cp = tstr + 2;
   3034 			    termc = *cp;
   3035 			} else if (tstr[1] == 'W' || tstr[1] == 'w') {
   3036 			    parsestate.oneBigWord = (tstr[1] == 'W');
   3037 			    newStr = nstr;
   3038 			    cp = tstr + 2;
   3039 			    termc = *cp;
   3040 			} else {
   3041 			    /* Found ":t<unrecognised>:" or
   3042 			     * ":t<unrecognised><endc>". */
   3043 			    goto bad_modifier;
   3044 			}
   3045 		    } else {
   3046 			/*
   3047 			 * Found ":t<unrecognised><unrecognised>".
   3048 			 */
   3049 			goto bad_modifier;
   3050 		    }
   3051 		} else {
   3052 		    /*
   3053 		     * Found ":t<endc>" or ":t:".
   3054 		     */
   3055 		    goto bad_modifier;
   3056 		}
   3057 		break;
   3058 	    }
   3059 	case 'N':
   3060 	case 'M':
   3061 	    {
   3062 		char    *pattern;
   3063 		const char *endpat; /* points just after end of pattern */
   3064 		char    *cp2;
   3065 		Boolean copy;	/* pattern should be, or has been, copied */
   3066 		Boolean needSubst;
   3067 		int nest;
   3068 
   3069 		copy = FALSE;
   3070 		needSubst = FALSE;
   3071 		nest = 1;
   3072 		/*
   3073 		 * In the loop below, ignore ':' unless we are at
   3074 		 * (or back to) the original brace level.
   3075 		 * XXX This will likely not work right if $() and ${}
   3076 		 * are intermixed.
   3077 		 */
   3078 		for (cp = tstr + 1;
   3079 		     *cp != '\0' && !(*cp == ':' && nest == 1);
   3080 		     cp++)
   3081 		    {
   3082 			if (*cp == '\\' &&
   3083 			    (cp[1] == ':' ||
   3084 			     cp[1] == endc || cp[1] == startc)) {
   3085 			    if (!needSubst) {
   3086 				copy = TRUE;
   3087 			    }
   3088 			    cp++;
   3089 			    continue;
   3090 			}
   3091 			if (*cp == '$') {
   3092 			    needSubst = TRUE;
   3093 			}
   3094 			if (*cp == '(' || *cp == '{')
   3095 			    ++nest;
   3096 			if (*cp == ')' || *cp == '}') {
   3097 			    --nest;
   3098 			    if (nest == 0)
   3099 				break;
   3100 			}
   3101 		    }
   3102 		termc = *cp;
   3103 		endpat = cp;
   3104 		if (copy) {
   3105 		    /*
   3106 		     * Need to compress the \:'s out of the pattern, so
   3107 		     * allocate enough room to hold the uncompressed
   3108 		     * pattern (note that cp started at tstr+1, so
   3109 		     * cp - tstr takes the null byte into account) and
   3110 		     * compress the pattern into the space.
   3111 		     */
   3112 		    pattern = bmake_malloc(cp - tstr);
   3113 		    for (cp2 = pattern, cp = tstr + 1;
   3114 			 cp < endpat;
   3115 			 cp++, cp2++)
   3116 			{
   3117 			    if ((*cp == '\\') && (cp+1 < endpat) &&
   3118 				(cp[1] == ':' || cp[1] == endc)) {
   3119 				cp++;
   3120 			    }
   3121 			    *cp2 = *cp;
   3122 			}
   3123 		    *cp2 = '\0';
   3124 		    endpat = cp2;
   3125 		} else {
   3126 		    /*
   3127 		     * Either Var_Subst or VarModify will need a
   3128 		     * nul-terminated string soon, so construct one now.
   3129 		     */
   3130 		    pattern = bmake_strndup(tstr+1, endpat - (tstr + 1));
   3131 		}
   3132 		if (needSubst) {
   3133 		    /*
   3134 		     * pattern contains embedded '$', so use Var_Subst to
   3135 		     * expand it.
   3136 		     */
   3137 		    cp2 = pattern;
   3138 		    pattern = Var_Subst(NULL, cp2, ctxt, errnum);
   3139 		    free(cp2);
   3140 		}
   3141 		if (DEBUG(VAR))
   3142 		    fprintf(debug_file, "Pattern[%s] for [%s] is [%s]\n",
   3143 			v->name, nstr, pattern);
   3144 		if (*tstr == 'M') {
   3145 		    newStr = VarModify(ctxt, &parsestate, nstr, VarMatch,
   3146 				       pattern);
   3147 		} else {
   3148 		    newStr = VarModify(ctxt, &parsestate, nstr, VarNoMatch,
   3149 				       pattern);
   3150 		}
   3151 		free(pattern);
   3152 		break;
   3153 	    }
   3154 	case 'S':
   3155 	    {
   3156 		VarPattern 	    pattern;
   3157 		Var_Parse_State tmpparsestate;
   3158 
   3159 		pattern.flags = 0;
   3160 		tmpparsestate = parsestate;
   3161 		delim = tstr[1];
   3162 		tstr += 2;
   3163 
   3164 		/*
   3165 		 * If pattern begins with '^', it is anchored to the
   3166 		 * start of the word -- skip over it and flag pattern.
   3167 		 */
   3168 		if (*tstr == '^') {
   3169 		    pattern.flags |= VAR_MATCH_START;
   3170 		    tstr += 1;
   3171 		}
   3172 
   3173 		cp = tstr;
   3174 		if ((pattern.lhs = VarGetPattern(ctxt, &parsestate, errnum,
   3175 						 &cp, delim,
   3176 						 &pattern.flags,
   3177 						 &pattern.leftLen,
   3178 						 NULL)) == NULL)
   3179 		    goto cleanup;
   3180 
   3181 		if ((pattern.rhs = VarGetPattern(ctxt, &parsestate, errnum,
   3182 						 &cp, delim, NULL,
   3183 						 &pattern.rightLen,
   3184 						 &pattern)) == NULL)
   3185 		    goto cleanup;
   3186 
   3187 		/*
   3188 		 * Check for global substitution. If 'g' after the final
   3189 		 * delimiter, substitution is global and is marked that
   3190 		 * way.
   3191 		 */
   3192 		for (;; cp++) {
   3193 		    switch (*cp) {
   3194 		    case 'g':
   3195 			pattern.flags |= VAR_SUB_GLOBAL;
   3196 			continue;
   3197 		    case '1':
   3198 			pattern.flags |= VAR_SUB_ONE;
   3199 			continue;
   3200 		    case 'W':
   3201 			tmpparsestate.oneBigWord = TRUE;
   3202 			continue;
   3203 		    }
   3204 		    break;
   3205 		}
   3206 
   3207 		termc = *cp;
   3208 		newStr = VarModify(ctxt, &tmpparsestate, nstr,
   3209 				   VarSubstitute,
   3210 				   &pattern);
   3211 
   3212 		/*
   3213 		 * Free the two strings.
   3214 		 */
   3215 		free(UNCONST(pattern.lhs));
   3216 		free(UNCONST(pattern.rhs));
   3217 		delim = '\0';
   3218 		break;
   3219 	    }
   3220 	case '?':
   3221 	    {
   3222 		VarPattern 	pattern;
   3223 		Boolean	value;
   3224 
   3225 		/* find ':', and then substitute accordingly */
   3226 
   3227 		pattern.flags = 0;
   3228 
   3229 		cp = ++tstr;
   3230 		delim = ':';
   3231 		if ((pattern.lhs = VarGetPattern(ctxt, &parsestate, errnum,
   3232 						 &cp, delim, NULL,
   3233 						 &pattern.leftLen,
   3234 						 NULL)) == NULL)
   3235 		    goto cleanup;
   3236 
   3237 		/* BROPEN or PROPEN */
   3238 		delim = endc;
   3239 		if ((pattern.rhs = VarGetPattern(ctxt, &parsestate, errnum,
   3240 						 &cp, delim, NULL,
   3241 						 &pattern.rightLen,
   3242 						 NULL)) == NULL)
   3243 		    goto cleanup;
   3244 
   3245 		termc = *--cp;
   3246 		delim = '\0';
   3247 		if (Cond_EvalExpression(NULL, v->name, &value, 0)
   3248 		    == COND_INVALID) {
   3249 		    Error("Bad conditional expression `%s' in %s?%s:%s",
   3250 			  v->name, v->name, pattern.lhs, pattern.rhs);
   3251 		    goto cleanup;
   3252 		}
   3253 
   3254 		if (value) {
   3255 		    newStr = UNCONST(pattern.lhs);
   3256 		    free(UNCONST(pattern.rhs));
   3257 		} else {
   3258 		    newStr = UNCONST(pattern.rhs);
   3259 		    free(UNCONST(pattern.lhs));
   3260 		}
   3261 		if (v->flags & VAR_JUNK) {
   3262 		    v->flags |= VAR_KEEP;
   3263 		}
   3264 		break;
   3265 	    }
   3266 #ifndef NO_REGEX
   3267 	case 'C':
   3268 	    {
   3269 		VarREPattern    pattern;
   3270 		char           *re;
   3271 		int             error;
   3272 		Var_Parse_State tmpparsestate;
   3273 
   3274 		pattern.flags = 0;
   3275 		tmpparsestate = parsestate;
   3276 		delim = tstr[1];
   3277 		tstr += 2;
   3278 
   3279 		cp = tstr;
   3280 
   3281 		if ((re = VarGetPattern(ctxt, &parsestate, errnum, &cp, delim,
   3282 					NULL, NULL, NULL)) == NULL)
   3283 		    goto cleanup;
   3284 
   3285 		if ((pattern.replace = VarGetPattern(ctxt, &parsestate,
   3286 						     errnum, &cp, delim, NULL,
   3287 						     NULL, NULL)) == NULL){
   3288 		    free(re);
   3289 		    goto cleanup;
   3290 		}
   3291 
   3292 		for (;; cp++) {
   3293 		    switch (*cp) {
   3294 		    case 'g':
   3295 			pattern.flags |= VAR_SUB_GLOBAL;
   3296 			continue;
   3297 		    case '1':
   3298 			pattern.flags |= VAR_SUB_ONE;
   3299 			continue;
   3300 		    case 'W':
   3301 			tmpparsestate.oneBigWord = TRUE;
   3302 			continue;
   3303 		    }
   3304 		    break;
   3305 		}
   3306 
   3307 		termc = *cp;
   3308 
   3309 		error = regcomp(&pattern.re, re, REG_EXTENDED);
   3310 		free(re);
   3311 		if (error)  {
   3312 		    *lengthPtr = cp - start + 1;
   3313 		    VarREError(error, &pattern.re, "RE substitution error");
   3314 		    free(pattern.replace);
   3315 		    goto cleanup;
   3316 		}
   3317 
   3318 		pattern.nsub = pattern.re.re_nsub + 1;
   3319 		if (pattern.nsub < 1)
   3320 		    pattern.nsub = 1;
   3321 		if (pattern.nsub > 10)
   3322 		    pattern.nsub = 10;
   3323 		pattern.matches = bmake_malloc(pattern.nsub *
   3324 					  sizeof(regmatch_t));
   3325 		newStr = VarModify(ctxt, &tmpparsestate, nstr,
   3326 				   VarRESubstitute,
   3327 				   &pattern);
   3328 		regfree(&pattern.re);
   3329 		free(pattern.replace);
   3330 		free(pattern.matches);
   3331 		delim = '\0';
   3332 		break;
   3333 	    }
   3334 #endif
   3335 	case 'Q':
   3336 	    if (tstr[1] == endc || tstr[1] == ':') {
   3337 		newStr = VarQuote(nstr);
   3338 		cp = tstr + 1;
   3339 		termc = *cp;
   3340 		break;
   3341 	    }
   3342 	    goto default_case;
   3343 	case 'T':
   3344 	    if (tstr[1] == endc || tstr[1] == ':') {
   3345 		newStr = VarModify(ctxt, &parsestate, nstr, VarTail,
   3346 				   NULL);
   3347 		cp = tstr + 1;
   3348 		termc = *cp;
   3349 		break;
   3350 	    }
   3351 	    goto default_case;
   3352 	case 'H':
   3353 	    if (tstr[1] == endc || tstr[1] == ':') {
   3354 		newStr = VarModify(ctxt, &parsestate, nstr, VarHead,
   3355 				   NULL);
   3356 		cp = tstr + 1;
   3357 		termc = *cp;
   3358 		break;
   3359 	    }
   3360 	    goto default_case;
   3361 	case 'E':
   3362 	    if (tstr[1] == endc || tstr[1] == ':') {
   3363 		newStr = VarModify(ctxt, &parsestate, nstr, VarSuffix,
   3364 				   NULL);
   3365 		cp = tstr + 1;
   3366 		termc = *cp;
   3367 		break;
   3368 	    }
   3369 	    goto default_case;
   3370 	case 'R':
   3371 	    if (tstr[1] == endc || tstr[1] == ':') {
   3372 		newStr = VarModify(ctxt, &parsestate, nstr, VarRoot,
   3373 				   NULL);
   3374 		cp = tstr + 1;
   3375 		termc = *cp;
   3376 		break;
   3377 	    }
   3378 	    goto default_case;
   3379 	case 'O':
   3380 	    {
   3381 		char otype;
   3382 
   3383 		cp = tstr + 1;	/* skip to the rest in any case */
   3384 		if (tstr[1] == endc || tstr[1] == ':') {
   3385 		    otype = 's';
   3386 		    termc = *cp;
   3387 		} else if ( (tstr[1] == 'x') &&
   3388 			    (tstr[2] == endc || tstr[2] == ':') ) {
   3389 		    otype = tstr[1];
   3390 		    cp = tstr + 2;
   3391 		    termc = *cp;
   3392 		} else {
   3393 		    goto bad_modifier;
   3394 		}
   3395 		newStr = VarOrder(nstr, otype);
   3396 		break;
   3397 	    }
   3398 	case 'u':
   3399 	    if (tstr[1] == endc || tstr[1] == ':') {
   3400 		newStr = VarUniq(nstr);
   3401 		cp = tstr + 1;
   3402 		termc = *cp;
   3403 		break;
   3404 	    }
   3405 	    goto default_case;
   3406 #ifdef SUNSHCMD
   3407 	case 's':
   3408 	    if (tstr[1] == 'h' && (tstr[2] == endc || tstr[2] == ':')) {
   3409 		const char *emsg;
   3410 		newStr = Cmd_Exec(nstr, &emsg);
   3411 		if (emsg)
   3412 		    Error(emsg, nstr);
   3413 		cp = tstr + 2;
   3414 		termc = *cp;
   3415 		break;
   3416 	    }
   3417 	    goto default_case;
   3418 #endif
   3419 	default:
   3420 	default_case:
   3421 	{
   3422 #ifdef SYSVVARSUB
   3423 	    /*
   3424 	     * This can either be a bogus modifier or a System-V
   3425 	     * substitution command.
   3426 	     */
   3427 	    VarPattern      pattern;
   3428 	    Boolean         eqFound;
   3429 
   3430 	    pattern.flags = 0;
   3431 	    eqFound = FALSE;
   3432 	    /*
   3433 	     * First we make a pass through the string trying
   3434 	     * to verify it is a SYSV-make-style translation:
   3435 	     * it must be: <string1>=<string2>)
   3436 	     */
   3437 	    cp = tstr;
   3438 	    cnt = 1;
   3439 	    while (*cp != '\0' && cnt) {
   3440 		if (*cp == '=') {
   3441 		    eqFound = TRUE;
   3442 		    /* continue looking for endc */
   3443 		}
   3444 		else if (*cp == endc)
   3445 		    cnt--;
   3446 		else if (*cp == startc)
   3447 		    cnt++;
   3448 		if (cnt)
   3449 		    cp++;
   3450 	    }
   3451 	    if (*cp == endc && eqFound) {
   3452 
   3453 		/*
   3454 		 * Now we break this sucker into the lhs and
   3455 		 * rhs. We must null terminate them of course.
   3456 		 */
   3457 		delim='=';
   3458 		cp = tstr;
   3459 		if ((pattern.lhs = VarGetPattern(ctxt, &parsestate,
   3460 						 errnum, &cp, delim, &pattern.flags,
   3461 						 &pattern.leftLen, NULL)) == NULL)
   3462 		    goto cleanup;
   3463 		delim = endc;
   3464 		if ((pattern.rhs = VarGetPattern(ctxt, &parsestate,
   3465 						 errnum, &cp, delim, NULL, &pattern.rightLen,
   3466 						 &pattern)) == NULL)
   3467 		    goto cleanup;
   3468 
   3469 		/*
   3470 		 * SYSV modifications happen through the whole
   3471 		 * string. Note the pattern is anchored at the end.
   3472 		 */
   3473 		termc = *--cp;
   3474 		delim = '\0';
   3475 		if (pattern.leftLen == 0 && *nstr == '\0') {
   3476 		    newStr = nstr;	/* special case */
   3477 		} else {
   3478 		    newStr = VarModify(ctxt, &parsestate, nstr,
   3479 				       VarSYSVMatch,
   3480 				       &pattern);
   3481 		}
   3482 		free(UNCONST(pattern.lhs));
   3483 		free(UNCONST(pattern.rhs));
   3484 	    } else
   3485 #endif
   3486 		{
   3487 		    Error("Unknown modifier '%c'", *tstr);
   3488 		    for (cp = tstr+1;
   3489 			 *cp != ':' && *cp != endc && *cp != '\0';
   3490 			 cp++)
   3491 			continue;
   3492 		    termc = *cp;
   3493 		    newStr = var_Error;
   3494 		}
   3495 	    }
   3496 	}
   3497 	if (DEBUG(VAR)) {
   3498 	    fprintf(debug_file, "Result[%s] of :%c is \"%s\"\n",
   3499 		v->name, modifier, newStr);
   3500 	}
   3501 
   3502 	if (newStr != nstr) {
   3503 	    if (*freePtr) {
   3504 		free(nstr);
   3505 		*freePtr = NULL;
   3506 	    }
   3507 	    nstr = newStr;
   3508 	    if (nstr != var_Error && nstr != varNoError) {
   3509 		*freePtr = nstr;
   3510 	    }
   3511 	}
   3512 	if (termc == '\0' && endc != '\0') {
   3513 	    Error("Unclosed variable specification (expecting '%c') for \"%s\" (value \"%s\") modifier %c", endc, v->name, nstr, modifier);
   3514 	} else if (termc == ':') {
   3515 	    cp++;
   3516 	}
   3517 	tstr = cp;
   3518     }
   3519  out:
   3520     *lengthPtr = tstr - start;
   3521     return (nstr);
   3522 
   3523  bad_modifier:
   3524     /* "{(" */
   3525     Error("Bad modifier `:%.*s' for %s", (int)strcspn(tstr, ":)}"), tstr,
   3526 	  v->name);
   3527 
   3528  cleanup:
   3529     *lengthPtr = cp - start;
   3530     if (delim != '\0')
   3531 	Error("Unclosed substitution for %s (%c missing)",
   3532 	      v->name, delim);
   3533     if (*freePtr) {
   3534 	free(*freePtr);
   3535 	*freePtr = NULL;
   3536     }
   3537     return (var_Error);
   3538 }
   3539 
   3540 /*-
   3541  *-----------------------------------------------------------------------
   3542  * Var_Parse --
   3543  *	Given the start of a variable invocation, extract the variable
   3544  *	name and find its value, then modify it according to the
   3545  *	specification.
   3546  *
   3547  * Input:
   3548  *	str		The string to parse
   3549  *	ctxt		The context for the variable
   3550  *	errnum		TRUE if undefined variables are an error
   3551  *	lengthPtr	OUT: The length of the specification
   3552  *	freePtr		OUT: Non-NULL if caller should free *freePtr
   3553  *
   3554  * Results:
   3555  *	The (possibly-modified) value of the variable or var_Error if the
   3556  *	specification is invalid. The length of the specification is
   3557  *	placed in *lengthPtr (for invalid specifications, this is just
   3558  *	2...?).
   3559  *	If *freePtr is non-NULL then it's a pointer that the caller
   3560  *	should pass to free() to free memory used by the result.
   3561  *
   3562  * Side Effects:
   3563  *	None.
   3564  *
   3565  *-----------------------------------------------------------------------
   3566  */
   3567 /* coverity[+alloc : arg-*4] */
   3568 char *
   3569 Var_Parse(const char *str, GNode *ctxt, Boolean errnum, int *lengthPtr,
   3570 	  void **freePtr)
   3571 {
   3572     const char	   *tstr;    	/* Pointer into str */
   3573     Var		   *v;		/* Variable in invocation */
   3574     Boolean 	    haveModifier;/* TRUE if have modifiers for the variable */
   3575     char	    endc;    	/* Ending character when variable in parens
   3576 				 * or braces */
   3577     char	    startc;	/* Starting character when variable in parens
   3578 				 * or braces */
   3579     int		    vlen;	/* Length of variable name */
   3580     const char 	   *start;	/* Points to original start of str */
   3581     char	   *nstr;	/* New string, used during expansion */
   3582     Boolean 	    dynamic;	/* TRUE if the variable is local and we're
   3583 				 * expanding it in a non-local context. This
   3584 				 * is done to support dynamic sources. The
   3585 				 * result is just the invocation, unaltered */
   3586     Var_Parse_State parsestate; /* Flags passed to helper functions */
   3587     char	  name[2];
   3588 
   3589     *freePtr = NULL;
   3590     dynamic = FALSE;
   3591     start = str;
   3592     parsestate.oneBigWord = FALSE;
   3593     parsestate.varSpace = ' ';	/* word separator */
   3594 
   3595     startc = str[1];
   3596     if (startc != PROPEN && startc != BROPEN) {
   3597 	/*
   3598 	 * If it's not bounded by braces of some sort, life is much simpler.
   3599 	 * We just need to check for the first character and return the
   3600 	 * value if it exists.
   3601 	 */
   3602 
   3603 	/* Error out some really stupid names */
   3604 	if (startc == '\0' || strchr(")}:$", startc)) {
   3605 	    *lengthPtr = 1;
   3606 	    return var_Error;
   3607 	}
   3608 	name[0] = startc;
   3609 	name[1] = '\0';
   3610 
   3611 	v = VarFind(name, ctxt, FIND_ENV | FIND_GLOBAL | FIND_CMD);
   3612 	if (v == NULL) {
   3613 	    *lengthPtr = 2;
   3614 
   3615 	    if ((ctxt == VAR_CMD) || (ctxt == VAR_GLOBAL)) {
   3616 		/*
   3617 		 * If substituting a local variable in a non-local context,
   3618 		 * assume it's for dynamic source stuff. We have to handle
   3619 		 * this specially and return the longhand for the variable
   3620 		 * with the dollar sign escaped so it makes it back to the
   3621 		 * caller. Only four of the local variables are treated
   3622 		 * specially as they are the only four that will be set
   3623 		 * when dynamic sources are expanded.
   3624 		 */
   3625 		switch (str[1]) {
   3626 		    case '@':
   3627 			return UNCONST("$(.TARGET)");
   3628 		    case '%':
   3629 			return UNCONST("$(.ARCHIVE)");
   3630 		    case '*':
   3631 			return UNCONST("$(.PREFIX)");
   3632 		    case '!':
   3633 			return UNCONST("$(.MEMBER)");
   3634 		}
   3635 	    }
   3636 	    /*
   3637 	     * Error
   3638 	     */
   3639 	    return (errnum ? var_Error : varNoError);
   3640 	} else {
   3641 	    haveModifier = FALSE;
   3642 	    tstr = &str[1];
   3643 	    endc = str[1];
   3644 	}
   3645     } else {
   3646 	Buffer buf;	/* Holds the variable name */
   3647 
   3648 	endc = startc == PROPEN ? PRCLOSE : BRCLOSE;
   3649 	Buf_Init(&buf, 0);
   3650 
   3651 	/*
   3652 	 * Skip to the end character or a colon, whichever comes first.
   3653 	 */
   3654 	for (tstr = str + 2;
   3655 	     *tstr != '\0' && *tstr != endc && *tstr != ':';
   3656 	     tstr++)
   3657 	{
   3658 	    /*
   3659 	     * A variable inside a variable, expand
   3660 	     */
   3661 	    if (*tstr == '$') {
   3662 		int rlen;
   3663 		void *freeIt;
   3664 		char *rval = Var_Parse(tstr, ctxt, errnum, &rlen, &freeIt);
   3665 		if (rval != NULL) {
   3666 		    Buf_AddBytes(&buf, strlen(rval), rval);
   3667 		}
   3668 		if (freeIt)
   3669 		    free(freeIt);
   3670 		tstr += rlen - 1;
   3671 	    }
   3672 	    else
   3673 		Buf_AddByte(&buf, *tstr);
   3674 	}
   3675 	if (*tstr == ':') {
   3676 	    haveModifier = TRUE;
   3677 	} else if (*tstr != '\0') {
   3678 	    haveModifier = FALSE;
   3679 	} else {
   3680 	    /*
   3681 	     * If we never did find the end character, return NULL
   3682 	     * right now, setting the length to be the distance to
   3683 	     * the end of the string, since that's what make does.
   3684 	     */
   3685 	    *lengthPtr = tstr - str;
   3686 	    Buf_Destroy(&buf, TRUE);
   3687 	    return (var_Error);
   3688 	}
   3689 	str = Buf_GetAll(&buf, &vlen);
   3690 
   3691 	/*
   3692 	 * At this point, str points into newly allocated memory from
   3693 	 * buf, containing only the name of the variable.
   3694 	 *
   3695 	 * start and tstr point into the const string that was pointed
   3696 	 * to by the original value of the str parameter.  start points
   3697 	 * to the '$' at the beginning of the string, while tstr points
   3698 	 * to the char just after the end of the variable name -- this
   3699 	 * will be '\0', ':', PRCLOSE, or BRCLOSE.
   3700 	 */
   3701 
   3702 	v = VarFind(str, ctxt, FIND_ENV | FIND_GLOBAL | FIND_CMD);
   3703 	/*
   3704 	 * Check also for bogus D and F forms of local variables since we're
   3705 	 * in a local context and the name is the right length.
   3706 	 */
   3707 	if ((v == NULL) && (ctxt != VAR_CMD) && (ctxt != VAR_GLOBAL) &&
   3708 		(vlen == 2) && (str[1] == 'F' || str[1] == 'D') &&
   3709 		strchr("@%*!<>", str[0]) != NULL) {
   3710 	    /*
   3711 	     * Well, it's local -- go look for it.
   3712 	     */
   3713 	    name[0] = *str;
   3714 	    name[1] = '\0';
   3715 	    v = VarFind(name, ctxt, 0);
   3716 
   3717 	    if (v != NULL) {
   3718 		/*
   3719 		 * No need for nested expansion or anything, as we're
   3720 		 * the only one who sets these things and we sure don't
   3721 		 * but nested invocations in them...
   3722 		 */
   3723 		nstr = Buf_GetAll(&v->val, NULL);
   3724 
   3725 		if (str[1] == 'D') {
   3726 		    nstr = VarModify(ctxt, &parsestate, nstr, VarHead,
   3727 				    NULL);
   3728 		} else {
   3729 		    nstr = VarModify(ctxt, &parsestate, nstr, VarTail,
   3730 				    NULL);
   3731 		}
   3732 		/*
   3733 		 * Resulting string is dynamically allocated, so
   3734 		 * tell caller to free it.
   3735 		 */
   3736 		*freePtr = nstr;
   3737 		*lengthPtr = tstr-start+1;
   3738 		Buf_Destroy(&buf, TRUE);
   3739 		VarFreeEnv(v, TRUE);
   3740 		return nstr;
   3741 	    }
   3742 	}
   3743 
   3744 	if (v == NULL) {
   3745 	    if (((vlen == 1) ||
   3746 		 (((vlen == 2) && (str[1] == 'F' || str[1] == 'D')))) &&
   3747 		((ctxt == VAR_CMD) || (ctxt == VAR_GLOBAL)))
   3748 	    {
   3749 		/*
   3750 		 * If substituting a local variable in a non-local context,
   3751 		 * assume it's for dynamic source stuff. We have to handle
   3752 		 * this specially and return the longhand for the variable
   3753 		 * with the dollar sign escaped so it makes it back to the
   3754 		 * caller. Only four of the local variables are treated
   3755 		 * specially as they are the only four that will be set
   3756 		 * when dynamic sources are expanded.
   3757 		 */
   3758 		switch (*str) {
   3759 		    case '@':
   3760 		    case '%':
   3761 		    case '*':
   3762 		    case '!':
   3763 			dynamic = TRUE;
   3764 			break;
   3765 		}
   3766 	    } else if ((vlen > 2) && (*str == '.') &&
   3767 		       isupper((unsigned char) str[1]) &&
   3768 		       ((ctxt == VAR_CMD) || (ctxt == VAR_GLOBAL)))
   3769 	    {
   3770 		int	len;
   3771 
   3772 		len = vlen - 1;
   3773 		if ((strncmp(str, ".TARGET", len) == 0) ||
   3774 		    (strncmp(str, ".ARCHIVE", len) == 0) ||
   3775 		    (strncmp(str, ".PREFIX", len) == 0) ||
   3776 		    (strncmp(str, ".MEMBER", len) == 0))
   3777 		{
   3778 		    dynamic = TRUE;
   3779 		}
   3780 	    }
   3781 
   3782 	    if (!haveModifier) {
   3783 		/*
   3784 		 * No modifiers -- have specification length so we can return
   3785 		 * now.
   3786 		 */
   3787 		*lengthPtr = tstr - start + 1;
   3788 		if (dynamic) {
   3789 		    char *pstr = bmake_strndup(start, *lengthPtr);
   3790 		    *freePtr = pstr;
   3791 		    Buf_Destroy(&buf, TRUE);
   3792 		    return(pstr);
   3793 		} else {
   3794 		    Buf_Destroy(&buf, TRUE);
   3795 		    return (errnum ? var_Error : varNoError);
   3796 		}
   3797 	    } else {
   3798 		/*
   3799 		 * Still need to get to the end of the variable specification,
   3800 		 * so kludge up a Var structure for the modifications
   3801 		 */
   3802 		v = bmake_malloc(sizeof(Var));
   3803 		v->name = UNCONST(str);
   3804 		Buf_Init(&v->val, 1);
   3805 		v->flags = VAR_JUNK;
   3806 		Buf_Destroy(&buf, FALSE);
   3807 	    }
   3808 	} else
   3809 	    Buf_Destroy(&buf, TRUE);
   3810     }
   3811 
   3812     if (v->flags & VAR_IN_USE) {
   3813 	Fatal("Variable %s is recursive.", v->name);
   3814 	/*NOTREACHED*/
   3815     } else {
   3816 	v->flags |= VAR_IN_USE;
   3817     }
   3818     /*
   3819      * Before doing any modification, we have to make sure the value
   3820      * has been fully expanded. If it looks like recursion might be
   3821      * necessary (there's a dollar sign somewhere in the variable's value)
   3822      * we just call Var_Subst to do any other substitutions that are
   3823      * necessary. Note that the value returned by Var_Subst will have
   3824      * been dynamically-allocated, so it will need freeing when we
   3825      * return.
   3826      */
   3827     nstr = Buf_GetAll(&v->val, NULL);
   3828     if (strchr(nstr, '$') != NULL) {
   3829 	nstr = Var_Subst(NULL, nstr, ctxt, errnum);
   3830 	*freePtr = nstr;
   3831     }
   3832 
   3833     v->flags &= ~VAR_IN_USE;
   3834 
   3835     if ((nstr != NULL) && haveModifier) {
   3836 	int used;
   3837 	/*
   3838 	 * Skip initial colon.
   3839 	 */
   3840 	tstr++;
   3841 
   3842 	nstr = ApplyModifiers(nstr, tstr, startc, endc,
   3843 			      v, ctxt, errnum, &used, freePtr);
   3844 	tstr += used;
   3845     }
   3846     if (*tstr) {
   3847 	*lengthPtr = tstr - start + 1;
   3848     } else {
   3849 	*lengthPtr = tstr - start;
   3850     }
   3851 
   3852     if (v->flags & VAR_FROM_ENV) {
   3853 	Boolean	  destroy = FALSE;
   3854 
   3855 	if (nstr != Buf_GetAll(&v->val, NULL)) {
   3856 	    destroy = TRUE;
   3857 	} else {
   3858 	    /*
   3859 	     * Returning the value unmodified, so tell the caller to free
   3860 	     * the thing.
   3861 	     */
   3862 	    *freePtr = nstr;
   3863 	}
   3864 	VarFreeEnv(v, destroy);
   3865     } else if (v->flags & VAR_JUNK) {
   3866 	/*
   3867 	 * Perform any free'ing needed and set *freePtr to NULL so the caller
   3868 	 * doesn't try to free a static pointer.
   3869 	 * If VAR_KEEP is also set then we want to keep str as is.
   3870 	 */
   3871 	if (!(v->flags & VAR_KEEP)) {
   3872 	    if (*freePtr) {
   3873 		free(nstr);
   3874 		*freePtr = NULL;
   3875 	    }
   3876 	    if (dynamic) {
   3877 		nstr = bmake_strndup(start, *lengthPtr);
   3878 		*freePtr = nstr;
   3879 	    } else {
   3880 		nstr = errnum ? var_Error : varNoError;
   3881 	    }
   3882 	}
   3883 	if (nstr != Buf_GetAll(&v->val, NULL))
   3884 	    Buf_Destroy(&v->val, TRUE);
   3885 	free(v->name);
   3886 	free(v);
   3887     }
   3888     return (nstr);
   3889 }
   3890 
   3891 /*-
   3892  *-----------------------------------------------------------------------
   3893  * Var_Subst  --
   3894  *	Substitute for all variables in the given string in the given context
   3895  *	If undefErr is TRUE, Parse_Error will be called when an undefined
   3896  *	variable is encountered.
   3897  *
   3898  * Input:
   3899  *	var		Named variable || NULL for all
   3900  *	str		the string which to substitute
   3901  *	ctxt		the context wherein to find variables
   3902  *	undefErr	TRUE if undefineds are an error
   3903  *
   3904  * Results:
   3905  *	The resulting string.
   3906  *
   3907  * Side Effects:
   3908  *	None. The old string must be freed by the caller
   3909  *-----------------------------------------------------------------------
   3910  */
   3911 char *
   3912 Var_Subst(const char *var, const char *str, GNode *ctxt, Boolean undefErr)
   3913 {
   3914     Buffer  	  buf;		    /* Buffer for forming things */
   3915     char    	  *val;		    /* Value to substitute for a variable */
   3916     int		  length;   	    /* Length of the variable invocation */
   3917     Boolean	  trailingBslash;   /* variable ends in \ */
   3918     void 	  *freeIt = NULL;    /* Set if it should be freed */
   3919     static Boolean errorReported;   /* Set true if an error has already
   3920 				     * been reported to prevent a plethora
   3921 				     * of messages when recursing */
   3922 
   3923     Buf_Init(&buf, 0);
   3924     errorReported = FALSE;
   3925     trailingBslash = FALSE;
   3926 
   3927     while (*str) {
   3928 	if (*str == '\n' && trailingBslash)
   3929 	    Buf_AddByte(&buf, ' ');
   3930 	if (var == NULL && (*str == '$') && (str[1] == '$')) {
   3931 	    /*
   3932 	     * A dollar sign may be escaped either with another dollar sign.
   3933 	     * In such a case, we skip over the escape character and store the
   3934 	     * dollar sign into the buffer directly.
   3935 	     */
   3936 	    str++;
   3937 	    Buf_AddByte(&buf, *str);
   3938 	    str++;
   3939 	} else if (*str != '$') {
   3940 	    /*
   3941 	     * Skip as many characters as possible -- either to the end of
   3942 	     * the string or to the next dollar sign (variable invocation).
   3943 	     */
   3944 	    const char  *cp;
   3945 
   3946 	    for (cp = str++; *str != '$' && *str != '\0'; str++)
   3947 		continue;
   3948 	    Buf_AddBytes(&buf, str - cp, cp);
   3949 	} else {
   3950 	    if (var != NULL) {
   3951 		int expand;
   3952 		for (;;) {
   3953 		    if (str[1] == '\0') {
   3954 			/* A trailing $ is kind of a special case */
   3955 			Buf_AddByte(&buf, str[0]);
   3956 			str++;
   3957 			expand = FALSE;
   3958 		    } else if (str[1] != PROPEN && str[1] != BROPEN) {
   3959 			if (str[1] != *var || strlen(var) > 1) {
   3960 			    Buf_AddBytes(&buf, 2, str);
   3961 			    str += 2;
   3962 			    expand = FALSE;
   3963 			}
   3964 			else
   3965 			    expand = TRUE;
   3966 			break;
   3967 		    }
   3968 		    else {
   3969 			const char *p;
   3970 
   3971 			/*
   3972 			 * Scan up to the end of the variable name.
   3973 			 */
   3974 			for (p = &str[2]; *p &&
   3975 			     *p != ':' && *p != PRCLOSE && *p != BRCLOSE; p++)
   3976 			    if (*p == '$')
   3977 				break;
   3978 			/*
   3979 			 * A variable inside the variable. We cannot expand
   3980 			 * the external variable yet, so we try again with
   3981 			 * the nested one
   3982 			 */
   3983 			if (*p == '$') {
   3984 			    Buf_AddBytes(&buf, p - str, str);
   3985 			    str = p;
   3986 			    continue;
   3987 			}
   3988 
   3989 			if (strncmp(var, str + 2, p - str - 2) != 0 ||
   3990 			    var[p - str - 2] != '\0') {
   3991 			    /*
   3992 			     * Not the variable we want to expand, scan
   3993 			     * until the next variable
   3994 			     */
   3995 			    for (;*p != '$' && *p != '\0'; p++)
   3996 				continue;
   3997 			    Buf_AddBytes(&buf, p - str, str);
   3998 			    str = p;
   3999 			    expand = FALSE;
   4000 			}
   4001 			else
   4002 			    expand = TRUE;
   4003 			break;
   4004 		    }
   4005 		}
   4006 		if (!expand)
   4007 		    continue;
   4008 	    }
   4009 
   4010 	    val = Var_Parse(str, ctxt, undefErr, &length, &freeIt);
   4011 
   4012 	    /*
   4013 	     * When we come down here, val should either point to the
   4014 	     * value of this variable, suitably modified, or be NULL.
   4015 	     * Length should be the total length of the potential
   4016 	     * variable invocation (from $ to end character...)
   4017 	     */
   4018 	    if (val == var_Error || val == varNoError) {
   4019 		/*
   4020 		 * If performing old-time variable substitution, skip over
   4021 		 * the variable and continue with the substitution. Otherwise,
   4022 		 * store the dollar sign and advance str so we continue with
   4023 		 * the string...
   4024 		 */
   4025 		if (oldVars) {
   4026 		    str += length;
   4027 		} else if (undefErr) {
   4028 		    /*
   4029 		     * If variable is undefined, complain and skip the
   4030 		     * variable. The complaint will stop us from doing anything
   4031 		     * when the file is parsed.
   4032 		     */
   4033 		    if (!errorReported) {
   4034 			Parse_Error(PARSE_FATAL,
   4035 				     "Undefined variable \"%.*s\"",length,str);
   4036 		    }
   4037 		    str += length;
   4038 		    errorReported = TRUE;
   4039 		} else {
   4040 		    Buf_AddByte(&buf, *str);
   4041 		    str += 1;
   4042 		}
   4043 	    } else {
   4044 		/*
   4045 		 * We've now got a variable structure to store in. But first,
   4046 		 * advance the string pointer.
   4047 		 */
   4048 		str += length;
   4049 
   4050 		/*
   4051 		 * Copy all the characters from the variable value straight
   4052 		 * into the new string.
   4053 		 */
   4054 		length = strlen(val);
   4055 		Buf_AddBytes(&buf, length, val);
   4056 		trailingBslash = length > 0 && val[length - 1] == '\\';
   4057 	    }
   4058 	    if (freeIt) {
   4059 		free(freeIt);
   4060 		freeIt = NULL;
   4061 	    }
   4062 	}
   4063     }
   4064 
   4065     return Buf_DestroyCompact(&buf);
   4066 }
   4067 
   4068 /*-
   4069  *-----------------------------------------------------------------------
   4070  * Var_GetTail --
   4071  *	Return the tail from each of a list of words. Used to set the
   4072  *	System V local variables.
   4073  *
   4074  * Input:
   4075  *	file		Filename to modify
   4076  *
   4077  * Results:
   4078  *	The resulting string.
   4079  *
   4080  * Side Effects:
   4081  *	None.
   4082  *
   4083  *-----------------------------------------------------------------------
   4084  */
   4085 #if 0
   4086 char *
   4087 Var_GetTail(char *file)
   4088 {
   4089     return(VarModify(file, VarTail, NULL));
   4090 }
   4091 
   4092 /*-
   4093  *-----------------------------------------------------------------------
   4094  * Var_GetHead --
   4095  *	Find the leading components of a (list of) filename(s).
   4096  *	XXX: VarHead does not replace foo by ., as (sun) System V make
   4097  *	does.
   4098  *
   4099  * Input:
   4100  *	file		Filename to manipulate
   4101  *
   4102  * Results:
   4103  *	The leading components.
   4104  *
   4105  * Side Effects:
   4106  *	None.
   4107  *
   4108  *-----------------------------------------------------------------------
   4109  */
   4110 char *
   4111 Var_GetHead(char *file)
   4112 {
   4113     return(VarModify(file, VarHead, NULL));
   4114 }
   4115 #endif
   4116 
   4117 /*-
   4118  *-----------------------------------------------------------------------
   4119  * Var_Init --
   4120  *	Initialize the module
   4121  *
   4122  * Results:
   4123  *	None
   4124  *
   4125  * Side Effects:
   4126  *	The VAR_CMD and VAR_GLOBAL contexts are created
   4127  *-----------------------------------------------------------------------
   4128  */
   4129 void
   4130 Var_Init(void)
   4131 {
   4132     VAR_GLOBAL = Targ_NewGN("Global");
   4133     VAR_CMD = Targ_NewGN("Command");
   4134 
   4135 }
   4136 
   4137 
   4138 void
   4139 Var_End(void)
   4140 {
   4141 }
   4142 
   4143 
   4144 /****************** PRINT DEBUGGING INFO *****************/
   4145 static void
   4146 VarPrintVar(void *vp)
   4147 {
   4148     Var    *v = (Var *)vp;
   4149     fprintf(debug_file, "%-16s = %s\n", v->name, Buf_GetAll(&v->val, NULL));
   4150 }
   4151 
   4152 /*-
   4153  *-----------------------------------------------------------------------
   4154  * Var_Dump --
   4155  *	print all variables in a context
   4156  *-----------------------------------------------------------------------
   4157  */
   4158 void
   4159 Var_Dump(GNode *ctxt)
   4160 {
   4161     Hash_Search search;
   4162     Hash_Entry *h;
   4163 
   4164     for (h = Hash_EnumFirst(&ctxt->context, &search);
   4165 	 h != NULL;
   4166 	 h = Hash_EnumNext(&search)) {
   4167 	    VarPrintVar(Hash_GetValue(h));
   4168     }
   4169 }
   4170