(variable_expand): Rewrote computed variable name and substitution

reference handling to be simpler.  First expand the entire text between the
parens if it contains any $s, then examine the result of that for
subtitution references and do no further expansion while parsing them.

1 files changed, 92 insertions, 110 deletions

diff --git a/expand.c b/expand.c
index bbbd6a7..867cf91 100644
--- a/expand.c
+++ b/expand.c
@@ -1,5 +1,5 @@
 /* Variable expansion functions for GNU Make.
-Copyright (C) 1988, 1989, 1991, 1992, 1993 Free Software Foundation, Inc.
+Copyright (C) 1988, 89, 91, 92, 93, 95 Free Software Foundation, Inc.
 This file is part of GNU Make.
 
 GNU Make is free software; you can redistribute it and/or modify
@@ -197,9 +197,9 @@ variable_expand (line)
 	    char openparen = *p;
 	    char closeparen = (openparen == '(') ? ')' : '}';
 	    register char *beg = p + 1;
+	    int free_beg = 0;
 	    char *op, *begp;
-	    char *end;
-	    char *colon = 0;
+	    char *end, *colon;
 
 	    op = o;
 	    begp = p;
@@ -213,10 +213,18 @@ variable_expand (line)
 	    /* Is there a variable reference inside the parens or braces?
 	       If so, expand it before expanding the entire reference.  */
 
-	    p1 = index (beg, closeparen);
+	    end = index (beg, closeparen);
+	    if (end == 0)
+	      {
+		/* Unterminated variable reference.  */
+		if (reading_filename != 0)
+		  makefile_fatal (reading_filename, *reading_lineno_ptr,
+				  "unterminated variable reference");
+		else
+		  fatal ("unterminated variable reference");
+	      }
+	    p1 = lindex (beg, end, '$');
 	    if (p1 != 0)
-	      p1 = lindex (beg, p1, '$');
-	    if (p1 != 0 && lindex (beg, p1, ':') == 0)
 	      {
 		/* BEG now points past the opening paren or brace.
 		   Count parens or braces until it is matched.  */
@@ -227,133 +235,107 @@ variable_expand (line)
 		      ++count;
 		    else if (*p == closeparen && --count < 0)
 		      break;
-		    else if (colon == 0 && count == 0 && *p == ':')
-		      /* Record where we found a colon, which
-			 indicates a substitution reference.
-			 We want to expand the text before the
-			 reference only.  */
-		      colon = p;
 		  }
 		/* If COUNT is >= 0, there were unmatched opening parens
 		   or braces, so we go to the simple case of a variable name
 		   such as `$($(a)'.  */
 		if (count < 0)
 		  {
-		    char *name = expand_argument (beg, colon == 0 ? p : colon);
-		    unsigned int namelen = strlen (name);
-		    if (colon == 0)
-		      {
-			/* This is a simple reference to the expanded name.  */
-			o = reference_variable (o, name, namelen);
-			free (name);
-			break;
-		      }
-		    else
-		      {
-			/* This is a substitution reference to the expanded
-			   name.  We replace the pending text with a copy
-			   containing the expanded name in place of the
-			   original name, and then fall through to
-			   the normal substitution reference code below.  */
-			unsigned int restlen = strlen (colon) + 1;
-			beg = (char *) alloca (namelen + restlen);
-			bcopy (name, beg, namelen);
-			bcopy (colon, &beg[namelen], restlen);
-			/* Point COLON into the new copy.  */
-			colon = &beg[namelen];
-		      }
+		    beg = expand_argument (beg, p); /* Expand the name.  */
+		    free_beg = 1; /* Remember to free BEG when finished.  */
+		    end = index (beg, '\0');
 		  }
 	      }
+	    else
+	      /* Advance P to the end of this reference.  After we are
+                 finished expanding this one, P will be incremented to
+                 continue the scan.  */
+	      p = end;
 
 	    /* This is not a reference to a built-in function and
-	       it does not contain any variable references inside.
-	       There are several things it could be.  */
+	       any variable references inside are now expanded.
+	       Is the resultant text a substitution reference?  */
 
-	    if (colon == 0)
-	      colon = index (beg, ':');
-	    if (colon != 0 && lindex (beg, colon, closeparen) == 0)
+	    colon = index (beg, ':');
+	    if (colon != 0)
 	      {
-		/* This is a substitution reference: $(FOO:A=B).  */
-		int count;
+		/* This looks like a substitution reference: $(FOO:A=B).  */
 		char *subst_beg, *subst_end, *replace_beg, *replace_end;
 
-		v = lookup_variable (beg, colon - beg);
-		if (v == 0)
-		  warn_undefined (beg, colon - beg);
-
 		subst_beg = colon + 1;
-		count = 0;
-		for (p = subst_beg; *p != '\0'; ++p)
+		subst_end = index (subst_beg, '=');
+		if (subst_end == 0)
+		  /* There is no = in sight.  Punt on the substitution
+		     reference and treat this as a variable name containing
+		     a colon, in the code below.  */
+		  colon = 0;
+		else
 		  {
-		    if (*p == openparen)
-		      ++count;
-		    else if (*p == closeparen)
-		      --count;
-		    else if (*p == '=' && count <= 0)
-		      break;
-		  }
-		if (count > 0)
-		  /* There were unmatched opening parens.  */
-		  return initialize_variable_output ();
-		subst_end = p;
-
-		replace_beg = p + 1;
-		count = 0;
-		for (p = replace_beg; *p != '\0'; ++p)
-		  {
-		    if (*p == openparen)
-		      ++count;
-		    else if (*p == closeparen && --count < 0)
-		      break;
-		  }
-		if (count > 0)
-		  /* There were unmatched opening parens.  */
-		  return initialize_variable_output ();
-		end = p;
-		replace_end = p;
+		    replace_beg = subst_end + 1;
+		    replace_end = end;
 
-		p = expand_argument (subst_beg, subst_end);
-		p1 = expand_argument (replace_beg, replace_end);
+		    /* Extract the variable name before the colon
+		       and look up that variable.  */
+		    v = lookup_variable (beg, colon - beg);
+		    if (v == 0)
+		      warn_undefined (beg, colon - beg);
 
-		if (v != 0 && *v->value != '\0')
-		  {
-		    char *value = (v->recursive ? recursively_expand (v)
-				   : v->value);
-		    char *percent = find_percent (p);
-		    if (percent != 0)
-		      o = patsubst_expand (o, value, p, p1,
-					   percent, (char *) 0);
-		    else
-		      o = subst_expand (o, value,
-					p, p1, strlen (p), strlen (p1),
-					0, 1);
-		    if (v->recursive)
-		      free (value);
+		    if (v != 0 && *v->value != '\0')
+		      {
+			char *value = (v->recursive ? recursively_expand (v)
+				       : v->value);
+			char *pattern, *percent;
+			if (free_beg)
+			  {
+			    *subst_end = '\0';
+			    pattern = subst_beg;
+			  }
+			else
+			  {
+			    pattern = alloca (subst_end - subst_beg + 1);
+			    bcopy (subst_beg, pattern, subst_end - subst_beg);
+			    pattern[subst_end - subst_beg] = '\0';
+			  }
+			percent = find_percent (pattern);
+			if (percent != 0)
+			  {
+			    char *replace;
+			    if (free_beg)
+			      {
+				*replace_end = '\0';
+				replace = replace_beg;
+			      }
+			    else
+			      {
+				replace = alloca (replace_end - replace_beg
+						  + 1);
+				bcopy (replace_beg, replace,
+				       replace_end - replace_beg);
+				replace[replace_end - replace_beg] = '\0';
+			      }
+			    
+			    o = patsubst_expand (o, value, pattern, replace,
+						 percent, (char *) 0);
+			  }
+			else
+			  o = subst_expand (o, value,
+					    pattern, replace_beg,
+					    strlen (pattern),
+					    end - replace_beg,
+					    0, 1);
+			if (v->recursive)
+			  free (value);
+		      }
 		  }
-
-		free (p);
-		free (p1);
 	      }
 
-	    /* No, this must be an ordinary variable reference.  */
-	    else
-	      {
-		/* Look up the value of the variable.  */
-		end = index (beg, closeparen);
-		if (end == 0)
-		  {
-		    /* Unterminated variable reference.  */
-		    if (reading_filename != 0)
-		      makefile_fatal (reading_filename, *reading_lineno_ptr,
-				      "unterminated variable reference");
-		    else
-		      fatal ("unterminated variable reference");
-		  }
+	    if (colon == 0)
+	      /* This is an ordinary variable reference.
+		 Look up the value of the variable.  */
 		o = reference_variable (o, beg, end - beg);
-	      }
 
-	    /* Advance p past the variable reference to resume scan.  */
-	    p = end;
+	  if (free_beg)
+	    free (beg);
 	  }
 	  break;