--- a/stage1_2/iec_flex.ll	Tue Nov 27 14:49:08 2012 +0000
+++ b/stage1_2/iec_flex.ll	Tue Nov 27 15:49:05 2012 +0000
@@ -144,15 +144,11 @@
 extern YYSTYPE yylval;
 
 /* The name of the file currently being parsed...
- * This variable is declared and read from the code generated by bison!
  * Note that flex accesses and updates this global variable
- * apropriately whenever it comes across an (*#include <filename> *)
- * directive...
- */
-/*
- NOTE: already defined in iec_bison.h 
-extern const char *current_filename;
-*/
+ * apropriately whenever it comes across an (*#include <filename> *) directive...
+ */
+const char *current_filename = NULL;
+
 
 
 /* We will not be using unput() in our flex code... */
@@ -249,6 +245,8 @@
 void unput_and_mark(const char c);
 
 void include_file(const char *include_filename);
+
+int GetNextChar(char *b, int maxBuffer);
 %}
 
 
@@ -466,12 +464,22 @@
 #define MAX_INCLUDE_DEPTH 16
 
 typedef struct {
+    int eof;
+    int lineNumber;
+    int currentChar;
+    int lineLength;
+    int currentTokenStart;
+    char *buffer;
+    FILE *in_file;
+  } tracking_t;
+
+typedef struct {
 	  YY_BUFFER_STATE buffer_state;
-	  tracking_t* env;
+	  tracking_t *env;
 	  const char *filename;
 	} include_stack_t;
 
-tracking_t* current_tracking;
+tracking_t *current_tracking = NULL;
 include_stack_t include_stack[MAX_INCLUDE_DEPTH];
 int include_stack_ptr = 0;
 
@@ -483,7 +491,6 @@
 	"/usr/lib/iec",
 	NULL /* must end with NULL!! */
 	};
-
 %}
 
 
@@ -885,6 +892,7 @@
 			       *       parser is called once again with a new file.
 			       *       (In fact, we currently do just that!)
 			       */
+			  fclose(yyin);
 			  free(current_tracking);
 			  if (include_stack_ptr == 0) {
 			      /* yyterminate() terminates the scanner and returns a 0 to the 
@@ -984,20 +992,20 @@
 	/* body_state -> (il_state | st_state) */
 <body_state>{
 {st_whitespace_no_pragma}			/* Eat any whitespace */
-{qualified_identifier}{st_whitespace}":="	  unput_text(0); BEGIN(st_state);
-{direct_variable_standard}{st_whitespace}":="	  unput_text(0); BEGIN(st_state);
+{qualified_identifier}{st_whitespace}":="	unput_text(0); BEGIN(st_state);
+{direct_variable_standard}{st_whitespace}":="	unput_text(0); BEGIN(st_state);
 {qualified_identifier}"["			unput_text(0); BEGIN(st_state);
 
-RETURN					unput_text(0); BEGIN(st_state);
-IF							unput_text(0); BEGIN(st_state);
+RETURN						unput_text(0); BEGIN(st_state);
+IF						unput_text(0); BEGIN(st_state);
 CASE						unput_text(0); BEGIN(st_state);
-FOR							unput_text(0); BEGIN(st_state);
+FOR						unput_text(0); BEGIN(st_state);
 WHILE						unput_text(0); BEGIN(st_state);
-REPEAT					unput_text(0); BEGIN(st_state);
+REPEAT						unput_text(0); BEGIN(st_state);
 EXIT						unput_text(0); BEGIN(st_state);
 
 	/* ':=' occurs only in transitions, and not Function or FB bodies! */
-:=							unput_text(0); BEGIN(st_state);
+:=						unput_text(0); BEGIN(st_state);
 
 	/* Hopefully, the above rules (along with the last one),
          * used to distinguish ST from IL, are 
@@ -1649,6 +1657,60 @@
 %%
 
 
+/*************************/
+/* Tracking Functions... */
+/*************************/
+
+#define MAX_BUFFER_LENGTH 1000
+
+tracking_t *GetNewTracking(FILE* in_file) {
+  tracking_t* new_env = new tracking_t;
+  new_env->eof = 0;
+  new_env->lineNumber = 0;
+  new_env->currentChar = 0;
+  new_env->lineLength = 0;
+  new_env->currentTokenStart = 0;
+  new_env->buffer = (char*)malloc(MAX_BUFFER_LENGTH);
+  new_env->in_file = in_file;
+  return new_env;
+}
+
+
+/* GetNextChar: reads a character from input */
+int GetNextChar(char *b, int maxBuffer) {
+  char *p;
+  
+  if (  current_tracking->eof  )
+    return 0;
+  
+  while (  current_tracking->currentChar >= current_tracking->lineLength  ) {
+    current_tracking->currentChar = 0;
+    current_tracking->currentTokenStart = 1;
+    current_tracking->eof = false;
+    
+    p = fgets(current_tracking->buffer, MAX_BUFFER_LENGTH, current_tracking->in_file);
+    if (  p == NULL  ) {
+      if (  ferror(current_tracking->in_file)  )
+        return 0;
+      current_tracking->eof = true;
+      return 0;
+    }
+    
+    current_tracking->lineNumber++;
+    current_tracking->lineLength = strlen(current_tracking->buffer);
+  }
+  
+  b[0] = current_tracking->buffer[current_tracking->currentChar];
+  if (b[0] == ' ' || b[0] == '\t')
+    current_tracking->currentTokenStart++;
+  current_tracking->currentChar++;
+
+  return b[0]==0?0:1;
+}
+
+
+
+
 /***********************************/
 /* Utility function definitions... */
 /***********************************/
@@ -1691,7 +1753,7 @@
 /* insert the code (in <source_code>) into the source code we are parsing.
  * This is done by creating an artificial file with that new source code, and then 'including' the file
  */
-void include_string(const char *source_code) {
+void include_string_(const char *source_code) {
   FILE *tmp_file = tmpfile();
   
   if(tmp_file == NULL) {
@@ -1790,6 +1852,37 @@
 
 
 
+/*******************************/
+/* Public Interface for Bison. */
+/*******************************/
+
+/* The following functions will be called from inside bison code! */
+
+void include_string(const char *source_code) {include_string_(source_code);}
+
+
+/* Tell flex which file to parse. This function will not imediately start parsing the file.
+ * To parse the file, you then need to call yyparse()
+ *
+ * Returns -1 on error opening the file (and a valid errno), or 0 on success.
+ */
+int parse_file(const char *filename) {
+  FILE *filehandle = NULL;
+
+  if((filehandle = fopen(filename, "r")) == NULL) 
+    return -1;
+
+  yyin = filehandle;
+  current_filename = strdup(filename);
+  current_tracking = GetNewTracking(yyin);
+  return 0;
+}
+
+
+
+
+
+
 /*************************************/
 /* Include a main() function to test */
 /* the token parsing by flex....     */
@@ -1801,7 +1894,6 @@
 yystype yylval;
 YYLTYPE yylloc;
 
-const char *current_filename;