 @@ -1,14 +1,14 @@
-/*	$NetBSD: var.c,v 1.323 2020/07/26 18:11:12 rillig Exp $	*/
+/*	$NetBSD: var.c,v 1.324 2020/07/26 18:47:02 rillig Exp $	*/
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
+ *
  * This code is derived from software contributed to Berkeley by
  * Adam de Boor.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
 @@ -59,34 +59,34 @@
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: var.c,v 1.323 2020/07/26 18:11:12 rillig Exp $";
+static char rcsid[] = "$NetBSD: var.c,v 1.324 2020/07/26 18:47:02 rillig Exp $";
 #else
 #include <sys/cdefs.h>
 #ifndef lint
 #if 0
 static char sccsid[] = "@(#)var.c	8.3 (Berkeley) 3/19/94";
 #else
-__RCSID("$NetBSD: var.c,v 1.323 2020/07/26 18:11:12 rillig Exp $");
+__RCSID("$NetBSD: var.c,v 1.324 2020/07/26 18:47:02 rillig Exp $");
 #endif
 #endif /* not lint */
 #endif
 /*-
  * var.c --
  *	Variable-handling functions
+ *
  * Interface:
  *	Var_Set		    Set the value of a variable in the given
  *			    context. The variable is created if it doesn't
  *			    yet exist.
+ *
 @@ -1776,64 +1776,67 @@ VarRange(const char *str, int ac)
 	    Buf_AddByte(&buf, ' ');
 	Buf_AddInt(&buf, 1 + i);
+    }
     free(as);
     free(av);
     return Buf_Destroy(&buf, FALSE);
+}
 /*-
  * Parse a text part of a modifier such as the "from" and "to" in :S/from/to/
- * or the :@ modifier. Nested variables in the text are expanded unless
+ * or the :@ modifier, until the next unescaped delimiter.  The delimiter, as
- * VARE_NOSUBST is set.
+ * well as the backslash or the dollar, can be escaped with a backslash.
+ *
- * The text part is parsed until the next delimiter.  To escape the delimiter,
+ * Return the parsed (and possibly expanded) string, or NULL if no delimiter
- * a backslash or a dollar, put a backslash before it.
+ * was found.
+ *
- * Return the expanded string or NULL if the delimiter was missing.
+ * Nested variables in the text are expanded unless VARE_NOSUBST is set.
+ *
- * If pattern is specified, handle escaped ampersands and replace unescaped
+ * If out_length is specified, store the length of the returned string, just
- * ampersands with the lhs of the pattern (for the :S modifier).
+ * to save another strlen call.
  * If out_length is specified, return the string length of the buffer
  * (except on parse errors).
+ *
  * If out_pflags is specified and the last character of the pattern is a $,
- * set the VARP_ANCHOR_END bit of mpflags.
+ * set the VARP_ANCHOR_END bit of mpflags (for the first part of the :S
  * modifier).
+ *
  * If subst is specified, handle escaped ampersands and replace unescaped
  * ampersands with the lhs of the pattern (for the second part of the :S
  * modifier).
  */
 static char *
-ParseModifierPart(GNode *ctxt, const char **tstr, int delim,
+ParseModifierPart(const char **tstr, int delim, VarEvalFlags eflags,
-		  VarEvalFlags eflags, VarPatternFlags *out_pflags,
+		  GNode *ctxt, size_t *out_length,
-		  size_t *out_length, ModifyWord_SubstArgs *subst)
+		  VarPatternFlags *out_pflags, ModifyWord_SubstArgs *subst)
+{
     const char *cp;
     char *rstr;
     Buffer buf;
     VarEvalFlags errnum = eflags & VARE_UNDEFERR;
     Buf_Init(&buf, 0);
     /*
      * Skim through until the matching delimiter is found;
      * pick up variable substitutions on the way. Also allow
      * backslashes to quote the delimiter, $, and \, but don't
      * touch other backslashes.
      */
     for (cp = *tstr; *cp != '\0' && *cp != delim; cp++) {
-	Boolean is_escaped = cp[0] == '\\' && (cp[1] == delim ||
+	Boolean is_escaped = cp[0] == '\\' && (
-	    cp[1] == '\\' || cp[1] == '$' || (subst != NULL && cp[1] == '&'));
+	    cp[1] == delim || cp[1] == '\\' || cp[1] == '$' ||
 	    (cp[1] == '&' && subst != NULL));
 	if (is_escaped) {
 	    Buf_AddByte(&buf, cp[1]);
 	    cp++;
 	} else if (*cp == '$') {
 	    if (cp[1] == delim) {	/* Unescaped $ at end of pattern */
 		if (out_pflags != NULL)
 		    *out_pflags |= VARP_ANCHOR_END;
 		else
 		    Buf_AddByte(&buf, *cp);
 	    } else {
 		if (eflags & VARE_WANTRES) {
 		    char   *cp2;
 		    int     len;
 @@ -2064,37 +2067,35 @@ typedef struct {
 #define STRMOD_MATCHX(s, want, n) \
     (strncmp(s, want, n) == 0 && \
      (s[n] == st->endc || s[n] == ':' || s[n] == '='))
 #define CHARMOD_MATCH(c) (c == st->endc || c == ':')
 /* :@var@...${var}...@ */
 static Boolean
 ApplyModifier_Loop(const char *mod, ApplyModifiersState *st) {
     ModifyWord_LoopArgs args;
     args.ctx = st->ctxt;
     st->cp = mod + 1;
     char delim = '@';
-    args.tvar = ParseModifierPart(st->ctxt, &st->cp, delim,
+    args.tvar = ParseModifierPart(&st->cp, delim, st->eflags & ~VARE_WANTRES,
-				  st->eflags & ~VARE_WANTRES,
+				  st->ctxt, NULL, NULL, NULL);
 				  NULL, NULL, NULL);
     if (args.tvar == NULL) {
 	st->missing_delim = delim;
 	return FALSE;
+    }
-    args.str = ParseModifierPart(st->ctxt, &st->cp, delim,
+    args.str = ParseModifierPart(&st->cp, delim, st->eflags & ~VARE_WANTRES,
-				 st->eflags & ~VARE_WANTRES,
+				 st->ctxt, NULL, NULL, NULL);
 				 NULL, NULL, NULL);
     if (args.str == NULL) {
 	st->missing_delim = delim;
 	return FALSE;
+    }
     st->termc = *st->cp;
     args.eflags = st->eflags & (VARE_UNDEFERR | VARE_WANTRES);
     int prev_sep = st->sep;
     st->sep = ' ';		/* XXX: this is inconsistent */
     st->newStr = ModifyWords(st->ctxt, st->sep, st->oneBigWord, st->nstr,
 			     ModifyWord_Loop, &args);
     st->sep = prev_sep;
 @@ -2243,27 +2244,27 @@ ApplyModifier_Path(const char *mod, Appl
+    }
     if (!st->newStr)
 	st->newStr = bmake_strdup(st->v->name);
     st->cp = mod + 1;
     st->termc = *st->cp;
+}
 /* :!cmd! */
 static Boolean
 ApplyModifier_Exclam(const char *mod, ApplyModifiersState *st)
+{
     st->cp = mod + 1;
     char delim = '!';
-    char *cmd = ParseModifierPart(st->ctxt, &st->cp, delim, st->eflags,
+    char *cmd = ParseModifierPart(&st->cp, delim, st->eflags, st->ctxt,
 				  NULL, NULL, NULL);
     if (cmd == NULL) {
 	st->missing_delim = delim;
 	return FALSE;
+    }
     const char *emsg = NULL;
     if (st->eflags & VARE_WANTRES)
 	st->newStr = Cmd_Exec(cmd, &emsg);
     else
 	st->newStr = varNoError;
     free(cmd);
 @@ -2389,36 +2390,36 @@ ApplyModifier_Subst(const char * const m
     st->cp = mod + 2;
     /*
      * If pattern begins with '^', it is anchored to the
      * start of the word -- skip over it and flag pattern.
      */
     args.pflags = 0;
     if (*st->cp == '^') {
 	args.pflags |= VARP_ANCHOR_START;
 	st->cp++;
+    }
-    char *lhs = ParseModifierPart(st->ctxt, &st->cp, delim, st->eflags,
+    char *lhs = ParseModifierPart(&st->cp, delim, st->eflags, st->ctxt,
-				  &args.pflags, &args.lhsLen, NULL);
+				  &args.lhsLen, &args.pflags, NULL);
     if (lhs == NULL) {
 	st->missing_delim = delim;
 	return FALSE;
+    }
     args.lhs = lhs;
-    char *rhs = ParseModifierPart(st->ctxt, &st->cp, delim, st->eflags,
+    char *rhs = ParseModifierPart(&st->cp, delim, st->eflags, st->ctxt,
-				  NULL, &args.rhsLen, &args);
+				  &args.rhsLen, NULL, &args);
     if (rhs == NULL) {
 	st->missing_delim = delim;
 	return FALSE;
+    }
     args.rhs = rhs;
     /*
      * Check for global substitution. If 'g' after the final
      * delimiter, substitution is global and is marked that
      * way.
      */
     for (;; st->cp++) {
 	switch (*st->cp) {
 @@ -2448,35 +2449,35 @@ ApplyModifier_Subst(const char * const m
 /* :C,from,to, */
 static Boolean
 ApplyModifier_Regex(const char *mod, ApplyModifiersState *st)
+{
     ModifyWord_SubstRegexArgs args;
     args.pflags = 0;
     Boolean oneBigWord = st->oneBigWord;
     char delim = mod[1];
     st->cp = mod + 2;
-    char *re = ParseModifierPart(st->ctxt, &st->cp, delim,
+    char *re = ParseModifierPart(&st->cp, delim, st->eflags, st->ctxt,
-				 st->eflags, NULL, NULL, NULL);
+				 NULL, NULL, NULL);
     if (re == NULL) {
 	st->missing_delim = delim;
 	return FALSE;
+    }
-    args.replace = ParseModifierPart(st->ctxt, &st->cp, delim,
+    args.replace = ParseModifierPart(&st->cp, delim, st->eflags, st->ctxt,
-				     st->eflags, NULL, NULL, NULL);
+				     NULL, NULL, NULL);
     if (args.replace == NULL) {
 	free(re);
 	st->missing_delim = delim;
 	return FALSE;
+    }
     for (;; st->cp++) {
 	switch (*st->cp) {
 	case 'g':
 	    args.pflags |= VARP_SUB_GLOBAL;
 	    continue;
 	case '1':
 	    args.pflags |= VARP_SUB_ONE;
 @@ -2610,29 +2611,29 @@ ApplyModifier_To(const char *mod, ApplyM
 	st->cp = mod + 2;
 	st->termc = *st->cp;
     } else {
 	/* Found ":t<unrecognised>:" or ":t<unrecognised><endc>". */
 	return FALSE;
+    }
     return TRUE;
+}
 /* :[#], :[1], etc. */
 static int
 ApplyModifier_Words(const char *mod, ApplyModifiersState *st)
+{
-    st->cp = mod + 1;	/* point to char after '[' */
+    st->cp = mod + 1;		/* point to char after '[' */
     char delim = ']';		/* look for closing ']' */
-    char *estr = ParseModifierPart(st->ctxt, &st->cp, delim, st->eflags,
+    char *estr = ParseModifierPart(&st->cp, delim, st->eflags, st->ctxt,
 				   NULL, NULL, NULL);
     if (estr == NULL) {
 	st->missing_delim = delim;
 	return 'c';
+    }
     /* now st->cp points just after the closing ']' */
     if (st->cp[0] != ':' && st->cp[0] != st->endc)
 	goto bad_modifier;	/* Found junk after ']' */
     if (estr[0] == '\0')
 	goto bad_modifier;	/* empty square brackets in ":[]". */
 @@ -2750,36 +2751,36 @@ ApplyModifier_IfElse(const char *mod, Ap
     VarEvalFlags then_eflags = st->eflags & ~VARE_WANTRES;
     VarEvalFlags else_eflags = st->eflags & ~VARE_WANTRES;
     if (st->eflags & VARE_WANTRES) {
 	cond_rc = Cond_EvalExpression(NULL, st->v->name, &value, 0, FALSE);
 	if (cond_rc != COND_INVALID && value)
 	    then_eflags |= VARE_WANTRES;
 	if (cond_rc != COND_INVALID && !value)
 	    else_eflags |= VARE_WANTRES;
+    }
     st->cp = mod + 1;
     char delim = ':';
-    char *then_expr = ParseModifierPart(
+    char *then_expr = ParseModifierPart(&st->cp, delim, then_eflags, st->ctxt,
-	st->ctxt, &st->cp, delim, then_eflags, NULL, NULL, NULL);
+					NULL, NULL, NULL);
     if (then_expr == NULL) {
 	st->missing_delim = delim;
 	return FALSE;
+    }
     delim = st->endc;		/* BRCLOSE or PRCLOSE */
-    char *else_expr = ParseModifierPart(
+    char *else_expr = ParseModifierPart(&st->cp, delim, else_eflags, st->ctxt,
-	st->ctxt, &st->cp, delim, else_eflags, NULL, NULL, NULL);
+					NULL, NULL, NULL);
     if (else_expr == NULL) {
 	st->missing_delim = delim;
 	return FALSE;
+    }
     st->termc = *--st->cp;
     if (cond_rc == COND_INVALID) {
 	Error("Bad conditional expression `%s' in %s?%s:%s",
 	    st->v->name, st->v->name, then_expr, else_expr);
 	return FALSE;
+    }
     if (value) {
 @@ -2847,28 +2848,28 @@ ApplyModifier_Assign(const char *mod, Ap
     switch (op[0]) {
     case '+':
     case '?':
     case '!':
 	st->cp = mod + 3;
 	break;
     default:
 	st->cp = mod + 2;
 	break;
+    }
     char delim = st->startc == PROPEN ? PRCLOSE : BRCLOSE;
-    char *val = ParseModifierPart(st->ctxt, &st->cp, delim,
+    char *val = ParseModifierPart(&st->cp, delim, st->eflags, st->ctxt,
-				  st->eflags, NULL, NULL, NULL);
+				  NULL, NULL, NULL);
     if (st->v->flags & VAR_JUNK) {
 	/* restore original name */
 	free(st->v->name);
 	st->v->name = sv_name;
+    }
     if (val == NULL) {
 	st->missing_delim = delim;
 	return 'c';
+    }
     st->termc = *--st->cp;
     if (st->eflags & VARE_WANTRES) {
 @@ -2947,35 +2948,35 @@ ApplyModifier_SysV(const char *mod, Appl
 	    /* continue looking for st->endc */
 	} else if (*st->cp == st->endc)
 	    nest--;
 	else if (*st->cp == st->startc)
 	    nest++;
 	if (nest > 0)
 	    st->cp++;
+    }
     if (*st->cp != st->endc || !eqFound)
 	return 0;
     char delim = '=';
     st->cp = mod;
-    char *lhs = ParseModifierPart(st->ctxt, &st->cp, delim, st->eflags,
+    char *lhs = ParseModifierPart(&st->cp, delim, st->eflags, st->ctxt,
 				  NULL, NULL, NULL);
     if (lhs == NULL) {
 	st->missing_delim = delim;
 	return 'c';
+    }
     delim = st->endc;
-    char *rhs = ParseModifierPart(st->ctxt, &st->cp, delim, st->eflags,
+    char *rhs = ParseModifierPart(&st->cp, delim, st->eflags, st->ctxt,
 				  NULL, NULL, NULL);
     if (rhs == NULL) {
 	st->missing_delim = delim;
 	return 'c';
+    }
     /*
      * SYSV modifications happen through the whole
      * string. Note the pattern is anchored at the end.
      */
     st->termc = *--st->cp;
     if (lhs[0] == '\0' && *st->nstr == '\0') {
 	st->newStr = st->nstr;	/* special case */