Split Var_Subst() into two functions: Var_SubstOnly() which substitutes

only one variable and Var_Subst() which substitutes all. Split out the
test whether a variable should not be expanded into match_var().
Make access to the input string consistently using str[]. Remove two
unused functions: Var_GetTail() and Var_GetHead().

Patches:	7.184-7.189
Submitted by:	Max Okumoto <okumoto@ucsd.edu>

9 files changed, 174 insertions, 163 deletions

diff --git a/usr.bin/make/arch.c b/usr.bin/make/arch.c
index e9e9397..4898a87 100644
--- a/usr.bin/make/arch.c
+++ b/usr.bin/make/arch.c
@@ -249,7 +249,7 @@ Arch_ParseArchive(char **linePtr, Lst *nodeLst, GNode *ctxt)
 
 	*cp++ = '\0';
 	if (subLibName) {
-		libName = Buf_Peel(Var_Subst(NULL, libName, ctxt, TRUE));
+		libName = Buf_Peel(Var_Subst(libName, ctxt, TRUE));
 	}
 
 	for (;;) {
@@ -346,7 +346,7 @@ Arch_ParseArchive(char **linePtr, Lst *nodeLst, GNode *ctxt)
 			 * The results are just placed at the end of the
 			 * nodeLst we're returning.
 			 */
-			buf1 = Var_Subst(NULL, memName, ctxt, TRUE);
+			buf1 = Var_Subst(memName, ctxt, TRUE);
 			memName = Buf_Data(buf1);
 
 			sz = strlen(memName) + strlen(libName) + 3;
diff --git a/usr.bin/make/compat.c b/usr.bin/make/compat.c
index 2ab8416..d57b803 100644
--- a/usr.bin/make/compat.c
+++ b/usr.bin/make/compat.c
@@ -252,7 +252,7 @@ Compat_RunCommand(char *cmd, GNode *gn)
 	doit = FALSE;
 
 	cmdNode = Lst_Member(&gn->commands, cmd);
-	cmdStart = Buf_Peel(Var_Subst(NULL, cmd, gn, FALSE));
+	cmdStart = Buf_Peel(Var_Subst(cmd, gn, FALSE));
 
 	/*
 	 * brk_string will return an argv with a NULL in av[0], thus causing
diff --git a/usr.bin/make/for.c b/usr.bin/make/for.c
index 823a7cc..f0e0b4e 100644
--- a/usr.bin/make/for.c
+++ b/usr.bin/make/for.c
@@ -150,7 +150,7 @@ For_For(char *line)
 	 * Make a list with the remaining words
 	 * XXX should use brk_string here.
 	 */
-	sub = Buf_Peel(Var_Subst(NULL, ptr, VAR_CMD, FALSE));
+	sub = Buf_Peel(Var_Subst(ptr, VAR_CMD, FALSE));
 	for (ptr = sub; *ptr != '\0' && isspace((u_char)*ptr); ptr++)
 		;
 
@@ -271,7 +271,7 @@ For_Run(int lineno)
 		Var_Set(var, val, VAR_GLOBAL);
 
 		DEBUGF(FOR, ("--- %s = %s\n", var, val));
-		str = Buf_Peel(Var_Subst(var, Buf_Data(buf),
+		str = Buf_Peel(Var_SubstOnly(var, Buf_Data(buf),
 		    VAR_GLOBAL, FALSE));
 
 		Parse_FromString(str, lineno);
diff --git a/usr.bin/make/job.c b/usr.bin/make/job.c
index 07ac2b4..ba2af78 100644
--- a/usr.bin/make/job.c
+++ b/usr.bin/make/job.c
@@ -609,7 +609,7 @@ JobPrintCommand(char *cmd, Job *job)
 	 */
 	cmdNode = Lst_Member(&job->node->commands, cmd);
 
-	cmd = Buf_Peel(Var_Subst(NULL, cmd, job->node, FALSE));
+	cmd = Buf_Peel(Var_Subst(cmd, job->node, FALSE));
 	cmdStart = cmd;
 
 	Lst_Replace(cmdNode, cmdStart);
@@ -972,8 +972,8 @@ JobFinish(Job *job, int *status)
 		 */
 		for (ln = job->tailCmds; ln != NULL; ln = LST_NEXT(ln)) {
 			Lst_AtEnd(&postCommands->commands,
-			    Buf_Peel(Var_Subst(NULL, Lst_Datum(ln),
-			    job->node, FALSE)));
+			    Buf_Peel(
+				Var_Subst(Lst_Datum(ln), job->node, FALSE)));
 		}
 
 		job->node->made = MADE;
@@ -1655,8 +1655,8 @@ JobStart(GNode *gn, int flags, Job *previous)
 				for (ln = job->tailCmds; ln != NULL;
 				    ln = LST_NEXT(ln)) {
 					Lst_AtEnd(&postCommands->commands,
-					    Buf_Peel(Var_Subst(NULL,
-					    Lst_Datum(ln), job->node, FALSE)));
+					    Buf_Peel(Var_Subst(Lst_Datum(ln),
+					    job->node, FALSE)));
 				}
 				job->node->made = MADE;
 				Make_Update(job->node);
diff --git a/usr.bin/make/main.c b/usr.bin/make/main.c
index 2b8fd8a..d93628a 100644
--- a/usr.bin/make/main.c
+++ b/usr.bin/make/main.c
@@ -901,7 +901,7 @@ main(int argc, char **argv)
 		char	*ptr;
 		char	savec;
 
-		buf = Var_Subst(NULL, VPATH, VAR_CMD, FALSE);
+		buf = Var_Subst(VPATH, VAR_CMD, FALSE);
 
 		vpath = Buf_Data(buf);
 		do {
@@ -992,7 +992,7 @@ main(int argc, char **argv)
 				v = emalloc(strlen(name) + 1 + 3);
 				sprintf(v, "${%s}", name);
 
-				value = Buf_Peel(Var_Subst(NULL, v,
+				value = Buf_Peel(Var_Subst(v,
 				    VAR_GLOBAL, FALSE));
 				printf("%s\n", value);
 
diff --git a/usr.bin/make/parse.c b/usr.bin/make/parse.c
index fb48a77..3defe1d 100644
--- a/usr.bin/make/parse.c
+++ b/usr.bin/make/parse.c
@@ -1493,7 +1493,7 @@ Parse_DoVar(char *line, GNode *ctxt)
 		if (!Var_Exists(line, ctxt))
 			Var_Set(line, "", ctxt);
 
-		cp = Buf_Peel(Var_Subst(NULL, cp, ctxt, FALSE));
+		cp = Buf_Peel(Var_Subst(cp, ctxt, FALSE));
 
 		oldVars = oldOldVars;
 
@@ -1516,7 +1516,7 @@ Parse_DoVar(char *line, GNode *ctxt)
 			 * resulting string will need freeing when we're done,
 			 * so set freeCmd to TRUE.
 			 */
-			cp = Buf_Peel(Var_Subst(NULL, cp, VAR_CMD, TRUE));
+			cp = Buf_Peel(Var_Subst(cp, VAR_CMD, TRUE));
 			freeCmd = TRUE;
 		}
 
@@ -1655,7 +1655,7 @@ ParseTraditionalInclude(char *file)
 	 * Substitute for any variables in the file name before trying to
 	 * find the thing.
 	 */
-	file = Buf_Peel(Var_Subst(NULL, file, VAR_CMD, FALSE));
+	file = Buf_Peel(Var_Subst(file, VAR_CMD, FALSE));
 
 	/*
 	 * Now we know the file's name, we attempt to find the durn thing.
@@ -2127,7 +2127,7 @@ parse_include(char *file, int code __unused, int lineno __unused)
 	 * Substitute for any variables in the file name before trying to
 	 * find the thing.
 	 */
-	file = Buf_Peel(Var_Subst(NULL, file, VAR_CMD, FALSE));
+	file = Buf_Peel(Var_Subst(file, VAR_CMD, FALSE));
 
 	/*
 	 * Now we know the file's name and its search path, we attempt to
@@ -2227,7 +2227,7 @@ parse_message(char *line, int iserror, int lineno __unused)
 	while (isspace((u_char)*line))
 		line++;
 
-	line = Buf_Peel(Var_Subst(NULL, line, VAR_GLOBAL, FALSE));
+	line = Buf_Peel(Var_Subst(line, VAR_GLOBAL, FALSE));
 	Parse_Error(iserror ? PARSE_FATAL : PARSE_WARNING, "%s", line);
 	free(line);
 
@@ -2254,7 +2254,7 @@ parse_undef(char *line, int code __unused, int lineno __unused)
 	}
 	*cp = '\0';
 
-	cp = Buf_Peel(Var_Subst(NULL, line, VAR_CMD, FALSE));
+	cp = Buf_Peel(Var_Subst(line, VAR_CMD, FALSE));
 	Var_Delete(cp, VAR_GLOBAL);
 	free(cp);
 }
@@ -2468,7 +2468,7 @@ Parse_File(const char *name, FILE *stream)
 
 			ParseFinishLine();
 
-			cp = Buf_Peel(Var_Subst(NULL, line, VAR_CMD, TRUE));
+			cp = Buf_Peel(Var_Subst(line, VAR_CMD, TRUE));
 
 			free(line);
 			line = cp;
diff --git a/usr.bin/make/suff.c b/usr.bin/make/suff.c
index 94277d8..4ef59b6 100644
--- a/usr.bin/make/suff.c
+++ b/usr.bin/make/suff.c
@@ -1155,7 +1155,7 @@ SuffExpandVariables(GNode *parent, GNode *child, Lst *members)
 	Lst_Init(members);
 
 	DEBUGF(SUFF, ("Expanding \"%s\"...", child->name));
-	buf = Var_Subst(NULL, child->name, parent, TRUE);
+	buf = Var_Subst(child->name, parent, TRUE);
 	cp = Buf_Data(buf);
 
 	if (child->type & OP_ARCHV) {
diff --git a/usr.bin/make/var.c b/usr.bin/make/var.c
index 6be737c..cb62da7 100644
--- a/usr.bin/make/var.c
+++ b/usr.bin/make/var.c
@@ -222,7 +222,7 @@ VarPossiblyExpand(const char *name, GNode *ctxt)
 	Buffer	*buf;
 
 	if (strchr(name, '$') != NULL) {
-		buf = Var_Subst(NULL, name, ctxt, 0);
+		buf = Var_Subst(name, ctxt, 0);
 		return (Buf_Peel(buf));
 	} else {
 		return estrdup(name);
@@ -882,7 +882,7 @@ VarExpand(Var *v, VarParser *vp)
 	} else {
 		Buffer	*buf;
 
-		buf = Var_Subst(NULL, value, vp->ctxt, vp->err);
+		buf = Var_Subst(value, vp->ctxt, vp->err);
 		result = Buf_Peel(buf);
 	}
 
@@ -1715,9 +1715,9 @@ Var_Parse(const char input[], GNode *ctxt, Boolean err,
  *-----------------------------------------------------------------------
  */
 Buffer *
-Var_Subst(const char *var, const char *str, GNode *ctxt, Boolean err)
+Var_Subst(const char *str, GNode *ctxt, Boolean err)
 {
-	Boolean errorReported;
+	Boolean	errorReported;
 	Buffer *buf;		/* Buffer for forming things */
 
 	/*
@@ -1728,89 +1728,21 @@ Var_Subst(const char *var, const char *str, GNode *ctxt, Boolean err)
 	errorReported = FALSE;
 
 	buf = Buf_Init(0);
-	while (*str) {
-		if (var == NULL && (str[0] == '$') && (str[1] == '$')) {
+	while (str[0] != '\0') {
+		if ((str[0] == '$') && (str[1] == '$')) {
 			/*
-			 * A dollar sign may be escaped either with another
-			 * dollar sign. In such a case, we skip over the
-			 * escape character and store the dollar sign into
-			 * the buffer directly.
+			 * A dollar sign may be escaped with another dollar
+			 * sign.  In such a case, we skip over the escape
+			 * character and store the dollar sign into the
+			 * buffer directly.
 			 */
+			str++;
 			Buf_AddByte(buf, (Byte)str[0]);
-			str += 2;
+			str++;
 
 		} else if (str[0] == '$') {
-			/*
-			 * Variable invocation.
-			 */
-			if (var != NULL) {
-				int     expand;
-				for (;;) {
-					if (str[1] == OPEN_PAREN || str[1] == OPEN_BRACE) {
-						size_t  ln;
-						const char *p = str + 2;
-
-						/*
-						 * Scan up to the end of the
-						 * variable name.
-						 */
-						while (*p != '\0' &&
-						       *p != ':' &&
-						       *p != CLOSE_PAREN &&
-						       *p != CLOSE_BRACE &&
-						       *p != '$') {
-							++p;
-						}
-
-						/*
-						 * A variable inside the
-						 * variable. We cannot expand
-						 * the external variable yet,
-						 * so we try again with the
-						 * nested one
-						 */
-						if (*p == '$') {
-							Buf_AppendRange(buf, str, p);
-							str = p;
-							continue;
-						}
-						ln = p - (str + 2);
-						if (var[ln] == '\0' && strncmp(var, str + 2, ln) == 0) {
-							expand = TRUE;
-						} else {
-							/*
-							 * Not the variable
-							 * we want to expand,
-							 * scan until the
-							 * next variable
-							 */
-							while (*p != '$' && *p != '\0')
-								p++;
-
-							Buf_AppendRange(buf, str, p);
-							str = p;
-							expand = FALSE;
-						}
-					} else {
-						/*
-						 * Single letter variable
-						 * name
-						 */
-						if (var[1] == '\0' && var[0] == str[1]) {
-							expand = TRUE;
-						} else {
-							Buf_AddBytes(buf, 2, (const Byte *) str);
-							str += 2;
-							expand = FALSE;
-						}
-					}
-					break;
-				}
-				if (!expand)
-					continue;
-			}
-		    {
-			VarParser	subvp = {
+			/* Variable invocation. */
+			VarParser subvp = {
 				str,
 				str,
 				ctxt,
@@ -1849,21 +1781,14 @@ Var_Subst(const char *var, const char *str, GNode *ctxt, Boolean err)
 						Parse_Error(PARSE_FATAL,
 							    "Undefined variable \"%.*s\"", subvp.ptr - subvp.input, str);
 					}
-					str = subvp.ptr;
 					errorReported = TRUE;
+					str = subvp.ptr;
 				} else {
-					Buf_AddByte(buf, (Byte)*str);
-					str += 1;
+					Buf_AddByte(buf, (Byte)str[0]);
+					str++;
 				}
 			} else {
 				/*
-				 * We've now got a variable structure to
-				 * store in. But first, advance the string
-				 * pointer.
-				 */
-				str = subvp.ptr;
-
-				/*
 				 * Copy all the characters from the variable
 				 * value straight into the new string.
 				 */
@@ -1871,68 +1796,155 @@ Var_Subst(const char *var, const char *str, GNode *ctxt, Boolean err)
 				if (rfree) {
 					free(rval);
 				}
+				str = subvp.ptr;
 			}
-		    }
 		} else {
-			/*
-			 * Skip as many characters as possible -- either to
-			 * the end of the string or to the next dollar sign
-			 * (variable invocation).
-			 */
-			const char *cp = str;
-
-			do {
-				str++;
-			} while (str[0] != '$' && str[0] != '\0');
-
-			Buf_AppendRange(buf, cp, str);
+			Buf_AddByte(buf, (Byte)str[0]);
+			str++;
 		}
 	}
 
 	return (buf);
 }
 
-/*-
- *-----------------------------------------------------------------------
- * Var_GetTail --
- *	Return the tail from each of a list of words. Used to set the
- *	System V local variables.
- *
- * Results:
- *	The resulting string.
- *
- * Side Effects:
- *	None.
- *
- *-----------------------------------------------------------------------
- */
-char *
-Var_GetTail(char *file)
+static int
+match_var(const char str[], const char var[])
 {
+	const char	*start = str;
+	size_t		len;
+
+	str++;			/* consume '$' */
 
-	return (VarModify(file, VarTail, (void *)NULL));
+	if (str[0] == OPEN_PAREN || str[0] == OPEN_BRACE) {
+		str++;		/* consume opening paren or brace */
+
+		while (str[0] != '\0') {
+			if (str[0] == '$') {
+				/*
+				 * A variable inside the variable. We cannot
+				 * expand the external variable yet.
+				 */
+				return (str - start);
+			} else if (str[0] == ':' ||
+				   str[0] == CLOSE_PAREN ||
+				   str[0] == CLOSE_BRACE) {
+				len = str - (start + 2);
+
+				if (var[len] == '\0' && strncmp(var, start + 2, len) == 0) {
+					return (0);	/* match */
+				} else {
+					/*
+					 * Not the variable we want to
+					 * expand.
+					 */
+					return (str - start);
+				}
+			} else {
+				++str;
+			}
+		}
+		return (str - start);
+	} else {
+		/* Single letter variable name */
+		if (var[1] == '\0' && var[0] == str[0]) {
+			return (0);	/* match */
+		} else {
+			str++;	/* consume variable name */
+			return (str - start);
+		}
+	}
 }
 
-/*-
- *-----------------------------------------------------------------------
- * Var_GetHead --
- *	Find the leading components of a (list of) filename(s).
- *	XXX: VarHead does not replace foo by ., as (sun) System V make
- *	does.
- *
- * Results:
- *	The leading components.
- *
- * Side Effects:
- *	None.
- *
- *-----------------------------------------------------------------------
- */
-char *
-Var_GetHead(char *file)
+Buffer *
+Var_SubstOnly(const char *var, const char *str, GNode *ctxt, Boolean err)
 {
+	Boolean	errorReported;
+	Buffer	*buf;		/* Buffer for forming things */
 
-	return (VarModify(file, VarHead, (void *)NULL));
+	/*
+	 * Set TRUE if an error has already been reported to prevent a
+	 * plethora of messages when recursing. XXXHB this comment sounds
+	 * wrong.
+	 */
+	errorReported = FALSE;
+
+	buf = Buf_Init(0);
+	while (str[0] != '\0') {
+		if (str[0] == '$') {
+			int	skip;
+
+			skip = match_var(str, var);
+			if (skip > 0) {
+				Buf_AddBytes(buf, skip, str);
+				str += skip;
+			} else {
+				/* Variable invocation. */
+				VarParser	subvp = {
+					str,
+					str,
+					ctxt,
+					err
+				};
+				char	*rval;
+				Boolean	rfree;
+
+				rval = VarParse(&subvp, &rfree);
+
+				/*
+				 * When we get down here, rval should either
+				 * point to the value of this variable, or be
+				 * NULL.
+				 */
+				if (rval == var_Error || rval == varNoError) {
+					/*
+					 * If performing old-time variable
+					 * substitution, skip over the
+					 * variable and continue with the
+					 * substitution. Otherwise, store the
+					 * dollar sign and advance str so we
+					 * continue with the string...
+					 */
+					if (oldVars) {
+						str = subvp.ptr;
+					} else if (err) {
+						/*
+						 * If variable is undefined,
+						 * complain and skip the
+						 * variable. The complaint
+						 * will stop us from doing
+						 * anything when the file is
+						 * parsed.
+						 */
+						if (!errorReported) {
+							Parse_Error(PARSE_FATAL,
+								    "Undefined variable \"%.*s\"", subvp.ptr - subvp.input, str);
+						}
+						errorReported = TRUE;
+						str = subvp.ptr;
+					} else {
+						Buf_AddByte(buf, (Byte)str[0]);
+						str++;
+					}
+				} else {
+					/*
+					 * Copy all the characters from the
+					 * variable value straight into the
+					 * new string.
+					 */
+					Buf_Append(buf, rval);
+					if (rfree) {
+						free(rval);
+					}
+					str = subvp.ptr;
+				}
+			}
+		} else {
+			Buf_AddByte(buf, (Byte)str[0]);
+			str++;
+		}
+	}
+
+	return (buf);
 }
 
 /*-
diff --git a/usr.bin/make/var.h b/usr.bin/make/var.h
index f5fb9c6..a81e743 100644
--- a/usr.bin/make/var.h
+++ b/usr.bin/make/var.h
@@ -93,14 +93,13 @@ void Var_Append(const char *, const char *, struct GNode *);
 void Var_Delete(const char *, struct GNode *);
 void Var_Dump(const struct GNode *);
 Boolean Var_Exists(const char *, struct GNode *);
-char *Var_GetHead(char *);
-char *Var_GetTail(char *);
 void Var_Init(char **);
 char *Var_Parse(const char *, struct GNode *, Boolean, size_t *, Boolean *);
 char *Var_Quote(const char *);
 void Var_Set(const char *, const char *, struct GNode *);
 void Var_SetEnv(const char *, struct GNode *);
-struct Buffer *Var_Subst(const char *, const char *, struct GNode *, Boolean);
+struct Buffer *Var_Subst(const char *, struct GNode *, Boolean);
+struct Buffer *Var_SubstOnly(const char *, const char *, struct GNode *, Boolean);
 char *Var_Value(const char *, struct GNode *, char **);
 
 /*