cw/main.c

       if(debug)printf("I got: ");
       if (var_bind->tree->type == CONSTANT) {
         if(debug){
-          printf("CONSTANT\n");
           print_leaf(var_bind->tree, 0);
         }
       } else {
       return ret_val;
     } else {
       printf("HELP called a function with no return!!\n");
+      exit(1);
     }
   }
   if (tree->type == IF) {
     if (debug) printf("Adding %d and %d\n", lhs->value, rhs->value);
     int result = lhs->value + rhs->value;
     return anon_binding((NODE*) get_int_token(result));
-  }
+ }
   if (tree->type == '-') {
     TOKEN* lhs = (TOKEN*) recursive_interpret(tree->left, env_ptr)->tree;
     TOKEN* rhs = (TOKEN*) recursive_interpret(tree->right, env_ptr)->tree;

cw/simple.c

+int whammy(int a) {
+  int x = a;
+  return x + 5;
+}
+
+function twice(function f) {
+  int g(int x) { return f(f(x)); }
+  return g;
+}
+
 int main() {
   int b = 4;
 

cw/simple.c.orig

+<<<<<<< HEAD
+int whammy(int a) {
+  int x = a;
+  return x + 5;
+}
+
+function twice(function f) {
+  int g(int x) { return f(f(x)); }
+  return g;
+}
+
+=======
+>>>>>>> 890548e7968c2e8be77eb6170819538f116397bd
+int main() {
+  int b = 4;
+
+  int a = b();
+
+  return x;
+}
+

cw/simple_BACKUP_23755.c

+<<<<<<< HEAD
+int whammy(int a) {
+  int x = a;
+  return x + 5;
+}
+
+function twice(function f) {
+  int g(int x) { return f(f(x)); }
+  return g;
+}
+
+=======
+>>>>>>> 890548e7968c2e8be77eb6170819538f116397bd
+int main() {
+  int b = 4;
+
+  int a = b();
+
+  return x;
+}
+

cw/simple_BACKUP_24791.c

+<<<<<<< HEAD
+int whammy(int a) {
+  int x = a;
+  return x + 5;
+}
+
+function twice(function f) {
+  int g(int x) { return f(f(x)); }
+  return g;
+}
+
+=======
+>>>>>>> 890548e7968c2e8be77eb6170819538f116397bd
+int main() {
+  int b = 4;
+
+  int a = b();
+
+  return x;
+}
+

cw/simple_BASE_23755.c

+int whammy(int a) {
+  return a + 5;
+}
+
+function twice(function f) {
+  int g(int x) { return f(f(x)); }
+  return g;
+}
+
+int main() {
+  x = twice(whammy);
+
+  return x(2);
+}
+

cw/simple_BASE_24791.c

+int whammy(int a) {
+  return a + 5;
+}
+
+function twice(function f) {
+  int g(int x) { return f(f(x)); }
+  return g;
+}
+
+int main() {
+  x = twice(whammy);
+
+  return x(2);
+}
+

cw/simple_LOCAL_23755.c

+int whammy(int a) {
+  int x = a;
+  return x + 5;
+}
+
+function twice(function f) {
+  int g(int x) { return f(f(x)); }
+  return g;
+}
+
+int main() {
+  x = twice(whammy);
+
+  return x(2);
+}
+

cw/simple_LOCAL_24791.c

+int whammy(int a) {
+  int x = a;
+  return x + 5;
+}
+
+function twice(function f) {
+  int g(int x) { return f(f(x)); }
+  return g;
+}
+
+int main() {
+  x = twice(whammy);
+
+  return x(2);
+}
+

cw/simple_REMOTE_23755.c

+int main() {
+  int b = 4;
+
+  int a = b();
+
+  return x;
+}
+

cw/simple_REMOTE_24791.c

+int main() {
+  int b = 4;
+
+  int a = b();
+
+  return x;
+}
+

cw/tests/twice.c

 }
 
 int main() {
-  x = twice(whammy);
+  doublewhammy = twice(whammy);
 
-  return x(2);
+  return doublewhammy(2);
 }
 

cw/tests/var_maths.c

-/* ##answer: 11*/
+/* ##answer: 30*/
 int main() {
   int x = 5;
+  int y = x - 4;
+  int z = 10 - x;
+  int w = x % z;
 
-  return x + 3 * 2;
+  return x*x + z / (w + y);
 }

tac/C.tab.h

-/* A Bison parser, made by GNU Bison 2.3.  */
+/* A Bison parser, made by GNU Bison 3.0.4.  */
 
-/* Skeleton interface for Bison's Yacc-like parsers in C
+/* Bison interface for Yacc-like parsers in C
 
-   Copyright (C) 1984, 1989, 1990, 2000, 2001, 2002, 2003, 2004, 2005, 2006
-   Free Software Foundation, Inc.
+   Copyright (C) 1984, 1989-1990, 2000-2015 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 51 Franklin Street, Fifth Floor,
-   Boston, MA 02110-1301, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* As a special exception, you may create a larger work that contains
    part or all of the Bison parser skeleton and distribute that work
    This special exception was added by the Free Software Foundation in
    version 2.2 of Bison.  */
 
-/* Tokens.  */
+#ifndef YY_YY_C_TAB_H_INCLUDED
+# define YY_YY_C_TAB_H_INCLUDED
+/* Debug traces.  */
+#ifndef YYDEBUG
+# define YYDEBUG 1
+#endif
+#if YYDEBUG
+extern int yydebug;
+#endif
+
+/* Token type.  */
 #ifndef YYTOKENTYPE
 # define YYTOKENTYPE
-   /* Put the tokens into the symbol table, so that GDB and other debuggers
-      know about them.  */
-   enum yytokentype {
-     IDENTIFIER = 258,
-     CONSTANT = 259,
-     STRING_LITERAL = 260,
-     LE_OP = 261,
-     GE_OP = 262,
-     EQ_OP = 263,
-     NE_OP = 264,
-     EXTERN = 265,
-     AUTO = 266,
-     INT = 267,
-     VOID = 268,
-     FUNCTION = 269,
-     APPLY = 270,
-     LEAF = 271,
-     IF = 272,
-     ELSE = 273,
-     WHILE = 274,
-     CONTINUE = 275,
-     BREAK = 276,
-     RETURN = 277
-   };
+  enum yytokentype
+  {
+    IDENTIFIER = 258,
+    CONSTANT = 259,
+    STRING_LITERAL = 260,
+    LE_OP = 261,
+    GE_OP = 262,
+    EQ_OP = 263,
+    NE_OP = 264,
+    EXTERN = 265,
+    AUTO = 266,
+    INT = 267,
+    VOID = 268,
+    FUNCTION = 269,
+    APPLY = 270,
+    LEAF = 271,
+    IF = 272,
+    ELSE = 273,
+    WHILE = 274,
+    CONTINUE = 275,
+    BREAK = 276,
+    RETURN = 277
+  };
 #endif
-/* Tokens.  */
-#define IDENTIFIER 258
-#define CONSTANT 259
-#define STRING_LITERAL 260
-#define LE_OP 261
-#define GE_OP 262
-#define EQ_OP 263
-#define NE_OP 264
-#define EXTERN 265
-#define AUTO 266
-#define INT 267
-#define VOID 268
-#define FUNCTION 269
-#define APPLY 270
-#define LEAF 271
-#define IF 272
-#define ELSE 273
-#define WHILE 274
-#define CONTINUE 275
-#define BREAK 276
-#define RETURN 277
-
-
-
 
+/* Value type.  */
 #if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
 typedef int YYSTYPE;
-# define yystype YYSTYPE /* obsolescent; will be withdrawn */
-# define YYSTYPE_IS_DECLARED 1
 # define YYSTYPE_IS_TRIVIAL 1
+# define YYSTYPE_IS_DECLARED 1
 #endif
 
+
 extern YYSTYPE yylval;
 
+int yyparse (void);
+
+#endif /* !YY_YY_C_TAB_H_INCLUDED  */

tac/lex.yy.c

 
 #define FLEX_SCANNER
 #define YY_FLEX_MAJOR_VERSION 2
-#define YY_FLEX_MINOR_VERSION 5
-#define YY_FLEX_SUBMINOR_VERSION 35
+#define YY_FLEX_MINOR_VERSION 6
+#define YY_FLEX_SUBMINOR_VERSION 1
 #if YY_FLEX_SUBMINOR_VERSION > 0
 #define FLEX_BETA
 #endif
 typedef uint16_t flex_uint16_t;
 typedef int32_t flex_int32_t;
 typedef uint32_t flex_uint32_t;
-typedef uint64_t flex_uint64_t;
 #else
 typedef signed char flex_int8_t;
 typedef short int flex_int16_t;
 typedef unsigned char flex_uint8_t; 
 typedef unsigned short int flex_uint16_t;
 typedef unsigned int flex_uint32_t;
-#endif /* ! C99 */
 
 /* Limits of integral types. */
 #ifndef INT8_MIN
 #define UINT32_MAX             (4294967295U)
 #endif
 
-#endif /* ! FLEXINT_H */
-
-#ifdef __cplusplus
-
-/* The "const" storage-class-modifier is valid. */
-#define YY_USE_CONST
-
-#else	/* ! __cplusplus */
-
-/* C99 requires __STDC__ to be defined as 1. */
-#if defined (__STDC__)
-
-#define YY_USE_CONST
+#endif /* ! C99 */
 
-#endif	/* defined (__STDC__) */
-#endif	/* ! __cplusplus */
+#endif /* ! FLEXINT_H */
 
-#ifdef YY_USE_CONST
+/* TODO: this is always defined, so inline it */
 #define yyconst const
+
+#if defined(__GNUC__) && __GNUC__ >= 3
+#define yynoreturn __attribute__((__noreturn__))
 #else
-#define yyconst
+#define yynoreturn
 #endif
 
 /* Returned upon end-of-file. */
 
 /* Size of default input buffer. */
 #ifndef YY_BUF_SIZE
+#ifdef __ia64__
+/* On IA-64, the buffer size is 16k, not 8k.
+ * Moreover, YY_BUF_SIZE is 2*YY_READ_BUF_SIZE in the general case.
+ * Ditto for the __ia64__ case accordingly.
+ */
+#define YY_BUF_SIZE 32768
+#else
 #define YY_BUF_SIZE 16384
+#endif /* __ia64__ */
 #endif
 
 /* The state buf must be large enough to hold one state per character in the main buffer.
 typedef size_t yy_size_t;
 #endif
 
-extern yy_size_t yyleng;
+extern int yyleng;
 
 extern FILE *yyin, *yyout;
 
 #define EOB_ACT_LAST_MATCH 2
 
     #define YY_LESS_LINENO(n)
+    #define YY_LINENO_REWIND_TO(ptr)
     
 /* Return all but the first "n" matched characters back to the input stream. */
 #define yyless(n) \
 	/* Size of input buffer in bytes, not including room for EOB
 	 * characters.
 	 */
-	yy_size_t yy_buf_size;
+	int yy_buf_size;
 
 	/* Number of characters read into yy_ch_buf, not including EOB
 	 * characters.
 	 */
-	yy_size_t yy_n_chars;
+	int yy_n_chars;
 
 	/* Whether we "own" the buffer - i.e., we know we created it,
 	 * and can realloc() it to grow it, and should free() it to
 
     int yy_bs_lineno; /**< The line count. */
     int yy_bs_column; /**< The column count. */
-    
+
 	/* Whether to try to fill the input buffer when we reach the
 	 * end of it.
 	 */
 /* Stack of input buffers. */
 static size_t yy_buffer_stack_top = 0; /**< index of top of stack. */
 static size_t yy_buffer_stack_max = 0; /**< capacity of stack. */
-static YY_BUFFER_STATE * yy_buffer_stack = 0; /**< Stack as an array. */
+static YY_BUFFER_STATE * yy_buffer_stack = NULL; /**< Stack as an array. */
 
 /* We provide macros for accessing buffer states in case in the
  * future we want to put the buffer states in a more general
 
 /* yy_hold_char holds the character lost when yytext is formed. */
 static char yy_hold_char;
-static yy_size_t yy_n_chars;		/* number of characters read into yy_ch_buf */
-yy_size_t yyleng;
+static int yy_n_chars;		/* number of characters read into yy_ch_buf */
+int yyleng;
 
 /* Points to current character in buffer. */
-static char *yy_c_buf_p = (char *) 0;
+static char *yy_c_buf_p = NULL;
 static int yy_init = 0;		/* whether we need to initialize */
 static int yy_start = 0;	/* start state number */
 
 
 YY_BUFFER_STATE yy_scan_buffer (char *base,yy_size_t size  );
 YY_BUFFER_STATE yy_scan_string (yyconst char *yy_str  );
-YY_BUFFER_STATE yy_scan_bytes (yyconst char *bytes,yy_size_t len  );
+YY_BUFFER_STATE yy_scan_bytes (yyconst char *bytes,int len  );
 
 void *yyalloc (yy_size_t  );
 void *yyrealloc (void *,yy_size_t  );
 
 typedef unsigned char YY_CHAR;
 
-FILE *yyin = (FILE *) 0, *yyout = (FILE *) 0;
+FILE *yyin = NULL, *yyout = NULL;
 
 typedef int yy_state_type;
 
 int yylineno = 1;
 
 extern char *yytext;
+#ifdef yytext_ptr
+#undef yytext_ptr
+#endif
 #define yytext_ptr yytext
 
 static yy_state_type yy_get_previous_state (void );
 static yy_state_type yy_try_NUL_trans (yy_state_type current_state  );
 static int yy_get_next_buffer (void );
-static void yy_fatal_error (yyconst char msg[]  );
+static void yynoreturn yy_fatal_error (yyconst char* msg  );
 
 /* Done after the current pattern has been matched and before the
  * corresponding action - sets up yytext.
  */
 #define YY_DO_BEFORE_ACTION \
 	(yytext_ptr) = yy_bp; \
-	yyleng = (yy_size_t) (yy_cp - yy_bp); \
+	yyleng = (int) (yy_cp - yy_bp); \
 	(yy_hold_char) = *yy_cp; \
 	*yy_cp = '\0'; \
 	(yy_c_buf_p) = yy_cp;
 
     } ;
 
-static yyconst flex_int32_t yy_ec[256] =
+static yyconst YY_CHAR yy_ec[256] =
     {   0,
         1,    1,    1,    1,    1,    1,    1,    1,    2,    3,
         2,    2,    1,    1,    1,    1,    1,    1,    1,    1,
         1,    1,    1,    1,    1
     } ;
 
-static yyconst flex_int32_t yy_meta[46] =
+static yyconst YY_CHAR yy_meta[46] =
     {   0,
         1,    1,    1,    1,    1,    1,    2,    1,    1,    1,
         1,    1,    1,    1,    3,    1,    1,    1,    1,    1,
         3,    3,    3,    1,    1
     } ;
 
-static yyconst flex_int16_t yy_base[101] =
+static yyconst flex_uint16_t yy_base[101] =
     {   0,
         0,    0,  130,  131,  131,  131,  110,   41,  131,  104,
       131,  131,  131,  131,  131,  131,  117,   32,  131,  131,
 
     } ;
 
-static yyconst flex_int16_t yy_nxt[177] =
+static yyconst flex_uint16_t yy_nxt[177] =
     {   0,
         4,    5,    6,    7,    8,    9,   10,   11,   12,   13,
        14,   15,   16,   17,   18,   19,   20,   21,   22,   23,
 
 FILE *yyget_in (void );
 
-void yyset_in  (FILE * in_str  );
+void yyset_in  (FILE * _in_str  );
 
 FILE *yyget_out (void );
 
-void yyset_out  (FILE * out_str  );
+void yyset_out  (FILE * _out_str  );
 
-yy_size_t yyget_leng (void );
+			int yyget_leng (void );
 
 char *yyget_text (void );
 
 int yyget_lineno (void );
 
-void yyset_lineno (int line_number  );
+void yyset_lineno (int _line_number  );
 
 /* Macros after this point can all be overridden by user definitions in
  * section 1.
 #endif
 #endif
 
+#ifndef YY_NO_UNPUT
+    
     static void yyunput (int c,char *buf_ptr  );
     
+#endif
+
 #ifndef yytext_ptr
 static void yy_flex_strncpy (char *,yyconst char *,int );
 #endif
 
 /* Amount of stuff to slurp up with each read. */
 #ifndef YY_READ_BUF_SIZE
+#ifdef __ia64__
+/* On IA-64, the buffer size is 16k, not 8k */
+#define YY_READ_BUF_SIZE 16384
+#else
 #define YY_READ_BUF_SIZE 8192
+#endif /* __ia64__ */
 #endif
 
 /* Copy whatever the last rule matched to the standard output. */
 /* This used to be an fputs(), but since the string might contain NUL's,
  * we now use fwrite().
  */
-#define ECHO fwrite( yytext, yyleng, 1, yyout )
+#define ECHO do { if (fwrite( yytext, (size_t) yyleng, 1, yyout )) {} } while (0)
 #endif
 
 /* Gets input and stuffs it into "buf".  number of characters read, or YY_NULL,
 	if ( YY_CURRENT_BUFFER_LVALUE->yy_is_interactive ) \
 		{ \
 		int c = '*'; \
-		yy_size_t n; \
+		size_t n; \
 		for ( n = 0; n < max_size && \
 			     (c = getc( yyin )) != EOF && c != '\n'; ++n ) \
 			buf[n] = (char) c; \
 	else \
 		{ \
 		errno=0; \
-		while ( (result = fread(buf, 1, max_size, yyin))==0 && ferror(yyin)) \
+		while ( (result = (int) fread(buf, 1, max_size, yyin))==0 && ferror(yyin)) \
 			{ \
 			if( errno != EINTR) \
 				{ \
 
 /* Code executed at the end of each rule. */
 #ifndef YY_BREAK
-#define YY_BREAK break;
+#define YY_BREAK /*LINTED*/break;
 #endif
 
 #define YY_RULE_SETUP \
  */
 YY_DECL
 {
-	register yy_state_type yy_current_state;
-	register char *yy_cp, *yy_bp;
-	register int yy_act;
+	yy_state_type yy_current_state;
+	char *yy_cp, *yy_bp;
+	int yy_act;
     
-#line 28 "C.flex"
-
-#line 722 "lex.yy.c"
-
 	if ( !(yy_init) )
 		{
 		(yy_init) = 1;
 		yy_load_buffer_state( );
 		}
 
-	while ( 1 )		/* loops until end-of-file is reached */
+	{
+#line 28 "C.flex"
+
+#line 758 "lex.yy.c"
+
+	while ( /*CONSTCOND*/1 )		/* loops until end-of-file is reached */
 		{
 		yy_cp = (yy_c_buf_p);
 
 yy_match:
 		do
 			{
-			register YY_CHAR yy_c = yy_ec[YY_SC_TO_UI(*yy_cp)];
+			YY_CHAR yy_c = yy_ec[YY_SC_TO_UI(*yy_cp)] ;
 			if ( yy_accept[yy_current_state] )
 				{
 				(yy_last_accepting_state) = yy_current_state;
 				if ( yy_current_state >= 98 )
 					yy_c = yy_meta[(unsigned int) yy_c];
 				}
-			yy_current_state = yy_nxt[yy_base[yy_current_state] + (unsigned int) yy_c];
+			yy_current_state = yy_nxt[yy_base[yy_current_state] + (flex_int16_t) yy_c];
 			++yy_cp;
 			}
 		while ( yy_base[yy_current_state] != 131 );
 #line 76 "C.flex"
 ECHO;
 	YY_BREAK
-#line 1005 "lex.yy.c"
+#line 1015 "lex.yy.c"
 case YY_STATE_EOF(INITIAL):
 	yyterminate();
 
 			"fatal flex scanner internal error--no action found" );
 	} /* end of action switch */
 		} /* end of scanning one token */
+	} /* end of user's declarations */
 } /* end of yylex */
 
 /* yy_get_next_buffer - try to read in a new buffer
  */
 static int yy_get_next_buffer (void)
 {
-    	register char *dest = YY_CURRENT_BUFFER_LVALUE->yy_ch_buf;
-	register char *source = (yytext_ptr);
-	register int number_to_move, i;
+    	char *dest = YY_CURRENT_BUFFER_LVALUE->yy_ch_buf;
+	char *source = (yytext_ptr);
+	int number_to_move, i;
 	int ret_val;
 
 	if ( (yy_c_buf_p) > &YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[(yy_n_chars) + 1] )
 	/* Try to read more data. */
 
 	/* First move last chars to start of buffer. */
-	number_to_move = (int) ((yy_c_buf_p) - (yytext_ptr)) - 1;
+	number_to_move = (int) ((yy_c_buf_p) - (yytext_ptr) - 1);
 
 	for ( i = 0; i < number_to_move; ++i )
 		*(dest++) = *(source++);
 
 	else
 		{
-			yy_size_t num_to_read =
+			int num_to_read =
 			YY_CURRENT_BUFFER_LVALUE->yy_buf_size - number_to_move - 1;
 
 		while ( num_to_read <= 0 )
 			{ /* Not enough room in the buffer - grow it. */
 
 			/* just a shorter name for the current buffer */
-			YY_BUFFER_STATE b = YY_CURRENT_BUFFER;
+			YY_BUFFER_STATE b = YY_CURRENT_BUFFER_LVALUE;
 
 			int yy_c_buf_p_offset =
 				(int) ((yy_c_buf_p) - b->yy_ch_buf);
 
 			if ( b->yy_is_our_buffer )
 				{
-				yy_size_t new_size = b->yy_buf_size * 2;
+				int new_size = b->yy_buf_size * 2;
 
 				if ( new_size <= 0 )
 					b->yy_buf_size += b->yy_buf_size / 8;
 				}
 			else
 				/* Can't grow it, we don't own it. */
-				b->yy_ch_buf = 0;
+				b->yy_ch_buf = NULL;
 
 			if ( ! b->yy_ch_buf )
 				YY_FATAL_ERROR(
 	else
 		ret_val = EOB_ACT_CONTINUE_SCAN;
 
-	if ((yy_size_t) ((yy_n_chars) + number_to_move) > YY_CURRENT_BUFFER_LVALUE->yy_buf_size) {
+	if (((yy_n_chars) + number_to_move) > YY_CURRENT_BUFFER_LVALUE->yy_buf_size) {
 		/* Extend the array by 50%, plus the number we really need. */
-		yy_size_t new_size = (yy_n_chars) + number_to_move + ((yy_n_chars) >> 1);
+		int new_size = (yy_n_chars) + number_to_move + ((yy_n_chars) >> 1);
 		YY_CURRENT_BUFFER_LVALUE->yy_ch_buf = (char *) yyrealloc((void *) YY_CURRENT_BUFFER_LVALUE->yy_ch_buf,new_size  );
 		if ( ! YY_CURRENT_BUFFER_LVALUE->yy_ch_buf )
 			YY_FATAL_ERROR( "out of dynamic memory in yy_get_next_buffer()" );
 
     static yy_state_type yy_get_previous_state (void)
 {
-	register yy_state_type yy_current_state;
-	register char *yy_cp;
+	yy_state_type yy_current_state;
+	char *yy_cp;
     
 	yy_current_state = (yy_start);
 
 	for ( yy_cp = (yytext_ptr) + YY_MORE_ADJ; yy_cp < (yy_c_buf_p); ++yy_cp )
 		{
-		register YY_CHAR yy_c = (*yy_cp ? yy_ec[YY_SC_TO_UI(*yy_cp)] : 1);
+		YY_CHAR yy_c = (*yy_cp ? yy_ec[YY_SC_TO_UI(*yy_cp)] : 1);
 		if ( yy_accept[yy_current_state] )
 			{
 			(yy_last_accepting_state) = yy_current_state;
 			if ( yy_current_state >= 98 )
 				yy_c = yy_meta[(unsigned int) yy_c];
 			}
-		yy_current_state = yy_nxt[yy_base[yy_current_state] + (unsigned int) yy_c];
+		yy_current_state = yy_nxt[yy_base[yy_current_state] + (flex_int16_t) yy_c];
 		}
 
 	return yy_current_state;
  */
     static yy_state_type yy_try_NUL_trans  (yy_state_type yy_current_state )
 {
-	register int yy_is_jam;
-    	register char *yy_cp = (yy_c_buf_p);
+	int yy_is_jam;
+    	char *yy_cp = (yy_c_buf_p);
 
-	register YY_CHAR yy_c = 1;
+	YY_CHAR yy_c = 1;
 	if ( yy_accept[yy_current_state] )
 		{
 		(yy_last_accepting_state) = yy_current_state;
 		if ( yy_current_state >= 98 )
 			yy_c = yy_meta[(unsigned int) yy_c];
 		}
-	yy_current_state = yy_nxt[yy_base[yy_current_state] + (unsigned int) yy_c];
+	yy_current_state = yy_nxt[yy_base[yy_current_state] + (flex_int16_t) yy_c];
 	yy_is_jam = (yy_current_state == 97);
 
-	return yy_is_jam ? 0 : yy_current_state;
+		return yy_is_jam ? 0 : yy_current_state;
 }
 
-    static void yyunput (int c, register char * yy_bp )
+#ifndef YY_NO_UNPUT
+
+    static void yyunput (int c, char * yy_bp )
 {
-	register char *yy_cp;
+	char *yy_cp;
     
     yy_cp = (yy_c_buf_p);
 
 	if ( yy_cp < YY_CURRENT_BUFFER_LVALUE->yy_ch_buf + 2 )
 		{ /* need to shift things up to make room */
 		/* +2 for EOB chars. */
-		register yy_size_t number_to_move = (yy_n_chars) + 2;
-		register char *dest = &YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[
+		int number_to_move = (yy_n_chars) + 2;
+		char *dest = &YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[
 					YY_CURRENT_BUFFER_LVALUE->yy_buf_size + 2];
-		register char *source =
+		char *source =
 				&YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[number_to_move];
 
 		while ( source > YY_CURRENT_BUFFER_LVALUE->yy_ch_buf )
 		yy_cp += (int) (dest - source);
 		yy_bp += (int) (dest - source);
 		YY_CURRENT_BUFFER_LVALUE->yy_n_chars =
-			(yy_n_chars) = YY_CURRENT_BUFFER_LVALUE->yy_buf_size;
+			(yy_n_chars) = (int) YY_CURRENT_BUFFER_LVALUE->yy_buf_size;
 
 		if ( yy_cp < YY_CURRENT_BUFFER_LVALUE->yy_ch_buf + 2 )
 			YY_FATAL_ERROR( "flex scanner push-back overflow" );
 	(yy_c_buf_p) = yy_cp;
 }
 
+#endif
+
 #ifndef YY_NO_INPUT
 #ifdef __cplusplus
     static int yyinput (void)
 
 		else
 			{ /* need more input */
-			yy_size_t offset = (yy_c_buf_p) - (yytext_ptr);
+			int offset = (yy_c_buf_p) - (yytext_ptr);
 			++(yy_c_buf_p);
 
 			switch ( yy_get_next_buffer(  ) )
 	if ( ! b )
 		YY_FATAL_ERROR( "out of dynamic memory in yy_create_buffer()" );
 
-	b->yy_buf_size = size;
+	b->yy_buf_size = (yy_size_t)size;
 
 	/* yy_ch_buf has to be 2 characters longer than the size given because
 	 * we need to put in 2 end-of-buffer characters.
 	yyfree((void *) b  );
 }
 
-#ifndef __cplusplus
-extern int isatty (int );
-#endif /* __cplusplus */
-    
 /* Initializes or reinitializes a buffer.
  * This function is sometimes called more than once on the same buffer,
  * such as during a yyrestart() or at EOF.
  */
 static void yyensure_buffer_stack (void)
 {
-	yy_size_t num_to_alloc;
+	int num_to_alloc;
     
 	if (!(yy_buffer_stack)) {
 
 		 * scanner will even need a stack. We use 2 instead of 1 to avoid an
 		 * immediate realloc on the next call.
          */
-		num_to_alloc = 1;
+      num_to_alloc = 1; /* After all that talk, this was set to 1 anyways... */
 		(yy_buffer_stack) = (struct yy_buffer_state**)yyalloc
 								(num_to_alloc * sizeof(struct yy_buffer_state*)
 								);
 		if ( ! (yy_buffer_stack) )
 			YY_FATAL_ERROR( "out of dynamic memory in yyensure_buffer_stack()" );
-								  
+
 		memset((yy_buffer_stack), 0, num_to_alloc * sizeof(struct yy_buffer_state*));
-				
+
 		(yy_buffer_stack_max) = num_to_alloc;
 		(yy_buffer_stack_top) = 0;
 		return;
 	if ((yy_buffer_stack_top) >= ((yy_buffer_stack_max)) - 1){
 
 		/* Increase the buffer to prepare for a possible push. */
-		int grow_size = 8 /* arbitrary grow size */;
+		yy_size_t grow_size = 8 /* arbitrary grow size */;
 
 		num_to_alloc = (yy_buffer_stack_max) + grow_size;
 		(yy_buffer_stack) = (struct yy_buffer_state**)yyrealloc
  * @param base the character buffer
  * @param size the size in bytes of the character buffer
  * 
- * @return the newly allocated buffer state object. 
+ * @return the newly allocated buffer state object.
  */
 YY_BUFFER_STATE yy_scan_buffer  (char * base, yy_size_t  size )
 {
 	     base[size-2] != YY_END_OF_BUFFER_CHAR ||
 	     base[size-1] != YY_END_OF_BUFFER_CHAR )
 		/* They forgot to leave room for the EOB's. */
-		return 0;
+		return NULL;
 
 	b = (YY_BUFFER_STATE) yyalloc(sizeof( struct yy_buffer_state )  );
 	if ( ! b )
 	b->yy_buf_size = size - 2;	/* "- 2" to take care of EOB's */
 	b->yy_buf_pos = b->yy_ch_buf = base;
 	b->yy_is_our_buffer = 0;
-	b->yy_input_file = 0;
+	b->yy_input_file = NULL;
 	b->yy_n_chars = b->yy_buf_size;
 	b->yy_is_interactive = 0;
 	b->yy_at_bol = 1;
 YY_BUFFER_STATE yy_scan_string (yyconst char * yystr )
 {
     
-	return yy_scan_bytes(yystr,strlen(yystr) );
+	return yy_scan_bytes(yystr,(int) strlen(yystr) );
 }
 
 /** Setup the input buffer state to scan the given bytes. The next call to yylex() will
  * scan from a @e copy of @a bytes.
- * @param bytes the byte buffer to scan
- * @param len the number of bytes in the buffer pointed to by @a bytes.
+ * @param yybytes the byte buffer to scan
+ * @param _yybytes_len the number of bytes in the buffer pointed to by @a bytes.
  * 
  * @return the newly allocated buffer state object.
  */
-YY_BUFFER_STATE yy_scan_bytes  (yyconst char * yybytes, yy_size_t  _yybytes_len )
+YY_BUFFER_STATE yy_scan_bytes  (yyconst char * yybytes, int  _yybytes_len )
 {
 	YY_BUFFER_STATE b;
 	char *buf;
-	yy_size_t n, i;
+	yy_size_t n;
+	int i;
     
 	/* Get memory for full buffer, including space for trailing EOB's. */
-	n = _yybytes_len + 2;
+	n = (yy_size_t) (_yybytes_len + 2);
 	buf = (char *) yyalloc(n  );
 	if ( ! buf )
 		YY_FATAL_ERROR( "out of dynamic memory in yy_scan_bytes()" );
 #define YY_EXIT_FAILURE 2
 #endif
 
-static void yy_fatal_error (yyconst char* msg )
+static void yynoreturn yy_fatal_error (yyconst char* msg )
 {
-    	(void) fprintf( stderr, "%s\n", msg );
+			(void) fprintf( stderr, "%s\n", msg );
 	exit( YY_EXIT_FAILURE );
 }
 
  */
 int yyget_lineno  (void)
 {
-        
+    
     return yylineno;
 }
 
 /** Get the length of the current token.
  * 
  */
-yy_size_t yyget_leng  (void)
+int yyget_leng  (void)
 {
         return yyleng;
 }
 }
 
 /** Set the current line number.
- * @param line_number
+ * @param _line_number line number
  * 
  */
-void yyset_lineno (int  line_number )
+void yyset_lineno (int  _line_number )
 {
     
-    yylineno = line_number;
+    yylineno = _line_number;
 }
 
 /** Set the input stream. This does not discard the current
  * input buffer.
- * @param in_str A readable stream.
+ * @param _in_str A readable stream.
  * 
  * @see yy_switch_to_buffer
  */
-void yyset_in (FILE *  in_str )
+void yyset_in (FILE *  _in_str )
 {
-        yyin = in_str ;
+        yyin = _in_str ;
 }
 
-void yyset_out (FILE *  out_str )
+void yyset_out (FILE *  _out_str )
 {
-        yyout = out_str ;
+        yyout = _out_str ;
 }
 
 int yyget_debug  (void)
         return yy_flex_debug;
 }
 
-void yyset_debug (int  bdebug )
+void yyset_debug (int  _bdebug )
 {
-        yy_flex_debug = bdebug ;
+        yy_flex_debug = _bdebug ;
 }
 
 static int yy_init_globals (void)
      * This function is called from yylex_destroy(), so don't allocate here.
      */
 
-    (yy_buffer_stack) = 0;
+    (yy_buffer_stack) = NULL;
     (yy_buffer_stack_top) = 0;
     (yy_buffer_stack_max) = 0;
-    (yy_c_buf_p) = (char *) 0;
+    (yy_c_buf_p) = NULL;
     (yy_init) = 0;
     (yy_start) = 0;
 
     yyin = stdin;
     yyout = stdout;
 #else
-    yyin = (FILE *) 0;
-    yyout = (FILE *) 0;
+    yyin = NULL;
+    yyout = NULL;
 #endif
 
     /* For future reference: Set errno on error, since we are called by
 #ifndef yytext_ptr
 static void yy_flex_strncpy (char* s1, yyconst char * s2, int n )
 {
-	register int i;
+		
+	int i;
 	for ( i = 0; i < n; ++i )
 		s1[i] = s2[i];
 }
 #ifdef YY_NEED_STRLEN
 static int yy_flex_strlen (yyconst char * s )
 {
-	register int n;
+	int n;
 	for ( n = 0; s[n]; ++n )
 		;
 
 
 void *yyalloc (yy_size_t  size )
 {
-	return (void *) malloc( size );
+			return malloc(size);
 }
 
 void *yyrealloc  (void * ptr, yy_size_t  size )
 {
+		
 	/* The cast to (char *) in the following accommodates both
 	 * implementations that use char* generic pointers, and those
 	 * that use void* generic pointers.  It works with the latter
 	 * any pointer type to void*, and deal with argument conversions
 	 * as though doing an assignment.
 	 */
-	return (void *) realloc( (char *) ptr, size );
+	return realloc(ptr, size);
 }
 
 void yyfree (void * ptr )
 {
-	free( (char *) ptr );	/* see yyrealloc() for (char *) cast */
+			free( (char *) ptr );	/* see yyrealloc() for (char *) cast */
 }
 
 #define YYTABLES_NAME "yytables"

tac/list.c

   return head;
 }
 
-ENV* create_new_function_env(ENV* env) {
+ENV* create_new_function_env(ENV* env, ENV* prenv) {
   ENV* n_env = (ENV*) malloc(sizeof(ENV));
   if (n_env == NULL) {
     perror("Failed to create environment");
   }
   n_env->bindings = NULL;
   n_env->parent = env;
+  n_env->counter = 0;
+  n_env->param_counter = 0;
+  n_env->arg_counter = 0;
+  n_env->previous = prenv;
   return n_env;
 }
 
-BIND* create_binding(char* name, NODE* tree, ENV* env_ptr) {
+BIND* create_binding(TOKEN* name, int sp_offset, ENV* env_ptr) {
   BIND* n_bind = (BIND*) malloc(sizeof(BIND));
   if (n_bind == NULL) {
     perror("Failed to create binding: ");
     exit(1);
   }
   n_bind->name = name;
-  n_bind->tree = tree;
+  n_bind->env_offset = sp_offset;
   n_bind->env  = env_ptr;
+  n_bind->is_saved = 0;
 
   return n_bind;
 }
   ptr->next = create_list(binding, NULL);
 }
 
-BIND* find_name_in_list(char* name, BLIST *head) {
+BIND* find_name_in_list(TOKEN* name, BLIST *head) {
   BLIST *ptr = head;
   while (ptr != NULL) {
-    if (strcmp(ptr->binding->name, name) == 0) {
+    if (name == ptr->binding->name) {
       return ptr->binding;
     }
     ptr = ptr->next;
   return NULL;
 }
 
-  BIND* find_name_in_env(char* name, ENV* env) {
+  BIND* find_name_in_env(TOKEN* name, ENV* env) {
     BIND* ptr = NULL;
     ENV* env_ptr = env;
     while (env_ptr != NULL && 

tac/list.h

 #include "types.h"
 
 BLIST* create_list(BIND*, BLIST*);
-BIND* create_binding(char*, NODE*, ENV*);
+BIND* create_binding(TOKEN*, int, ENV*);
 void append_list(BLIST*, BIND*);
-BIND* find_name_in_list(char*, BLIST*);
-BIND* find_name_in_env(char*, ENV*);
-ENV* create_new_function_env(ENV*);
+BIND* find_name_in_list(TOKEN*, BLIST*);
+BIND* find_name_in_env(TOKEN*, ENV*);
+ENV* create_new_function_env(ENV*, ENV*);
 void add_tac(TLIST*, int, TOKEN*, TOKEN*, TOKEN*);
 TAC_T* create_tac(int, TOKEN*, TOKEN*, TOKEN*);
 TLIST* new_tac_list(TAC_T*, TLIST*);

tac/main.c

 #include "types.h"
 #include "list.h"
 
+int debug = 0;
+
 extern TOKEN* lookup_token(char*);
 
 TOKEN* gen_tmp(void) {
   return tok->lexeme;
 }
 
+void print_tac_el(TAC_T* elem) {
+    int op = elem->op;
+    if (op == '=') printf("%s := %s\n", stok(elem->dst), stok(elem->src));
+    if (op=='+' || op=='-' || op=='*' || op=='/' || op =='%') printf("%s := %s %c %s\n", stok(elem->dst), stok(elem->src), op, stok(elem->tgt));
+    if (op == RETURN) printf("ret %s\n", stok(elem->src));
+    if (op == 'D') printf("func %s\n", stok(elem->dst));
+    if (op == '>' || op == '<') printf("if %s %c %s then %s\n", stok(elem->src), op, stok(elem->tgt), stok(elem->dst));
+    if (op == GE_OP) printf("if %s >= %s then %s\n", stok(elem->src), stok(elem->tgt), stok(elem->dst));
+    if (op == LE_OP) printf("if %s <= %s then %s\n", stok(elem->src), stok(elem->tgt), stok(elem->dst));
+    if (op == EQ_OP) printf("if %s == %s then %s\n", stok(elem->src), stok(elem->tgt), stok(elem->dst));
+    if (op == NE_OP) printf("if %s != %s then %s\n", stok(elem->src), stok(elem->tgt), stok(elem->dst));
+    if (op == IDENTIFIER) printf("%s\n", stok(elem->dst));
+    if (op == VOID) printf("goto %s\n", stok(elem->dst));
+    if (op == AUTO) printf("param %s\n", stok(elem->dst));
+    if (op == APPLY) printf("call %s, %s\n", stok(elem->dst), stok(elem->tgt));
+    if (op == 278) printf("arg %s\n", stok(elem->dst));
+    if (op == 279) printf("end %s\n\n", stok(elem->dst));
+}
+
 void print_tac(TLIST* tac_list) {
   TLIST *ptr = tac_list;
 
   while (ptr != NULL) {
-    int op = ptr->elem->op;
-    if (op == '=') printf("%s := %s\n", stok(ptr->elem->dst), stok(ptr->elem->src));
-    if (op=='+' || op=='-' || op=='*' || op=='/' || op =='%') printf("%s := %s %c %s\n", stok(ptr->elem->dst), stok(ptr->elem->src), op, stok(ptr->elem->tgt));
-    if (op == RETURN) printf("ret %s\n", stok(ptr->elem->src));
-    if (op == 'D') printf("\nfunc %s\n", stok(ptr->elem->dst));
-    if (op == '>' || op == '<') printf("if %s %c %s then %s\n", stok(ptr->elem->src), op, stok(ptr->elem->tgt), stok(ptr->elem->dst));
-    if (op == GE_OP) printf("if %s >= %s then %s\n", stok(ptr->elem->src), stok(ptr->elem->tgt), stok(ptr->elem->dst));
-    if (op == LE_OP) printf("if %s <= %s then %s\n", stok(ptr->elem->src), stok(ptr->elem->tgt), stok(ptr->elem->dst));
-    if (op == EQ_OP) printf("if %s == %s then %s\n", stok(ptr->elem->src), stok(ptr->elem->tgt), stok(ptr->elem->dst));
-    if (op == NE_OP) printf("if %s != %s then %s\n", stok(ptr->elem->src), stok(ptr->elem->tgt), stok(ptr->elem->dst));
-    if (op == IDENTIFIER) printf("%s\n", stok(ptr->elem->dst));
-    if (op == VOID) printf("goto %s\n", stok(ptr->elem->dst));
-    if (op == AUTO) printf("param %s\n", stok(ptr->elem->dst));
-    if (op == APPLY) printf("call %s, %s\n", stok(ptr->elem->dst), stok(ptr->elem->tgt));
-    if (op == 278) printf("arg %s\n", stok(ptr->elem->dst));
-    if (op == 279) printf("end %s\n", stok(ptr->elem->dst));
+    print_tac_el(ptr->elem);
     ptr = ptr->next;
   }
 }
       NODE **val_list;
       num_args = count_args(tree->right);
       val_list = get_val_list(tree->right);
+      TOKEN* arg_tokens[num_args];
+      for (int i = 0; i < num_args; i++) {
+        arg_tokens[i] = build_tac(val_list[i], tac);
+      }
       for (int i = 0; i < num_args; i++) {
-        TOKEN* arg_token = build_tac(val_list[i], tac);
-        new_tac(tac, arg_token, NULL, NULL, 278);
+        new_tac(tac, arg_tokens[i], NULL, NULL, 278);
       }
     }
     new_tac(tac, (TOKEN*) tree->left->left, NULL, ret_val, APPLY);
 
 int tmp_regs[10] = {8, 9, 10, 11, 12, 13, 14, 15, 24, 25};
 int svd_regs[8]  = {16, 17, 18, 19, 20, 21, 22, 23};
+int arg_regs[3] = {5, 6, 7};
 int tmp_cntr = 0;
-VARLOC** vartab;
+int var_cntr = 0;
 
-int is_imm(TOKEN *t) {
-  if (t->type==CONSTANT) return 1;
-  else return 0;
-}
-
-int find_var_idx(TOKEN* var) {
-  int i;
-  for (i = 0; i < 8; i++) { 
-    if (vartab[i]->var == var) {
-      return vartab[i]->loc_idx;
+int register_me(TOKEN* name, ENV* env) {
+  if (tmp_cntr == 10) tmp_cntr = 0;
+  if (name->type == CONSTANT) {
+    if (name->value == 0) {
+      return 0;
+    } else {
+      printf("li $%d, %d\n", tmp_regs[tmp_cntr], name->value);
+      return tmp_regs[tmp_cntr++];
     }
-  }
-  return -1;
-}
-
-int store_var(TOKEN* name) {
-  int i;
-  for (i = 0; i < 8; i++) {
-    if (vartab[i]->var == NULL) {
-      vartab[i]->var = name;
-      vartab[i]->loc_idx = svd_regs[i];
-      return vartab[i]->loc_idx;
-    } else if (name == vartab[i]->var) {
-      vartab[i]->loc_idx = svd_regs[i];
-      return svd_regs[i];
+  } else {
+    BIND* binding = find_name_in_list(name, env->bindings);
+    if (binding == NULL) {
+      BIND* new_bind;
+      if (name->lexeme[0] != '$') {
+        new_bind = create_binding(name, env->counter++, NULL);
+        if (env->bindings == NULL) env->bindings = create_list(new_bind, NULL);
+        else append_list(env->bindings, new_bind);
+        new_bind->is_saved = 1;
+        return svd_regs[new_bind->env_offset];
+      } else {
+        new_bind = create_binding(name, tmp_cntr++, NULL);
+        if (env->bindings == NULL) env->bindings = create_list(new_bind, NULL);
+        else append_list(env->bindings, new_bind);
+        return tmp_regs[new_bind->env_offset];
+      }
+    } else {
+      return binding->is_saved ? svd_regs[binding->env_offset] : tmp_regs[binding->env_offset];
     }
   }
-  printf("bugger\n");
-  exit(1);
 }
 
-void init_reg() {
-  int i;
-  vartab = (VARLOC**) malloc(8 * sizeof(VARLOC*));
-  for (i = 0; i < 8; i++) {
-    vartab[i] = (VARLOC*) malloc(sizeof(VARLOC));
-    vartab[i]->var = NULL;
-    vartab[i]->loc_idx = -1;
-  }
-}
-
-int alloc_register(TOKEN* val) {
-  int idx;
-  int imm = is_imm(val);
-  if (imm) {
-    if (val->value <= 32767 && val->value >= -32767) {
-      printf("ori $%d, $0, %d\n", tmp_regs[tmp_cntr], val->value);
-      idx = tmp_regs[tmp_cntr++];
-    } else {
-      printf("li $%d, %d\n", tmp_regs[tmp_cntr], val->value);
-      idx = tmp_regs[tmp_cntr++];
-    }
-  } else {
-    idx = find_var_idx(val);
-  }
-  if (tmp_cntr == 10) tmp_cntr = 0;
-  return idx;
+void alloc_function_env() {
+  printf("li $a0, 68\n");
+  printf("li $v0, 9\n");
+  printf("syscall\n");
 }
 
 void compile_tac(TLIST* tacs) {
+  ENV* env = create_new_function_env(NULL, NULL);
   printf("=====\n");
-  init_reg();
+  alloc_function_env();
+  printf("or $fp, $0, $v0\n");
+  printf("la $t0, main\n");
+  printf("sw $t0, 0($fp)\n");
+  printf("sw $0, 4($fp)\n");
+  printf("la $ra, done\n");
+  printf("j main\n");
   while(tacs != NULL) {
     TAC_T* t = tacs->elem;
+    if (debug) {
+      printf("#");
+      print_tac_el(t);
+    }
     if (t->op == '=') {
-      int src_idx = alloc_register(t->src);
-      printf("or $%d, $0, $%d\n", store_var(t->dst), src_idx);
+      int src = register_me(t->src, env);
+      int dst = register_me(t->dst, env);
+      printf("or $%d, $0, $%d\n", dst, src);
     }
     if (t->op == 'D') {
+      env = create_new_function_env(NULL, env);
       printf("%s:\n", t->dst->lexeme);
+      printf("sw $ra, 64($fp)\n");
     }
     if (t->op == '+') {
-      int tgt_idx = alloc_register(t->tgt);
-      int src_idx = alloc_register(t->src);
-      printf("add $%d, $%d, $%d\n", store_var(t->dst), src_idx, tgt_idx);
+      int src = register_me(t->src, env);
+      int dst = register_me(t->dst, env);
+      int tgt = register_me(t->tgt, env);
+      printf("add $%d, $%d, $%d\n", dst, src, tgt);
     }
     if (t->op == '-') {
-      int tgt_idx = alloc_register(t->tgt);
-      int src_idx = alloc_register(t->src);
-      printf("sub $%d, $%d, $%d\n", store_var(t->dst), src_idx, tgt_idx);
+      int src = register_me(t->src, env);
+      int dst = register_me(t->dst, env);
+      int tgt = register_me(t->tgt, env);
+      printf("sub $%d, $%d, $%d\n", dst, src, tgt);
     }
     if (t->op == '*') {
-      int tgt_idx = alloc_register(t->tgt);
-      int src_idx = alloc_register(t->src);
-      printf("mult $%d, $%d\n", src_idx, tgt_idx);
-      printf("mflo $%d\n", store_var(t->dst));
+      int src = register_me(t->src, env);
+      int dst = register_me(t->dst, env);
+      int tgt = register_me(t->tgt, env);
+      printf("mult $%d, $%d\n", src, tgt);
+      printf("mflo $%d\n", dst);
     }
     if (t->op == '/') {
-      int tgt_idx = alloc_register(t->tgt);
-      int src_idx = alloc_register(t->src);
-      printf("div $%d, $%d\n", src_idx, tgt_idx);
-      printf("mflo $%d\n", store_var(t->dst));
+      int src = register_me(t->src, env);
+      int dst = register_me(t->dst, env);
+      int tgt = register_me(t->tgt, env);
+      printf("div $%d, $%d\n", src, tgt);
+      printf("mflo $%d\n", dst);
     }
     if (t->op == '%') {
-      int tgt_idx = alloc_register(t->tgt);
-      int src_idx = alloc_register(t->src);
-      printf("div $%d, $%d\n", src_idx, tgt_idx);
-      printf("mfhi $%d\n", store_var(t->dst));
+      int src = register_me(t->src, env);
+      int dst = register_me(t->dst, env);
+      int tgt = register_me(t->tgt, env);
+      printf("div $%d, $%d\n", src, tgt);
+      printf("mfhi $%d\n", dst);
+    }
+    if (t->op == LE_OP) {
+      int src = register_me(t->src, env);
+      int tgt = register_me(t->tgt, env);
+      printf("ble $%d, $%d, %s\n", src, tgt, stok(t->dst));
+    }
+    if (t->op == GE_OP) {
+      int src = register_me(t->src, env);
+      int tgt = register_me(t->tgt, env);
+      printf("bge $%d, $%d, %s\n", src, tgt, stok(t->dst));
+    }
+    if (t->op == EQ_OP) {
+      int src = register_me(t->src, env);
+      int tgt = register_me(t->tgt, env);
+      printf("beq $%d, $%d, %s\n", src, tgt, stok(t->dst));
+    }
+    if (t->op == NE_OP) {
+      int src = register_me(t->src, env);
+      int tgt = register_me(t->tgt, env);
+      printf("bne $%d, $%d, %s\n", src, tgt, stok(t->dst));
+    }
+    if (t->op == '>') {
+      int src = register_me(t->src, env);
+      int tgt = register_me(t->tgt, env);
+      printf("bgt $%d, $%d, %s\n", src, tgt, stok(t->dst));
+    }
+    if (t->op == '<') {
+      int src = register_me(t->src, env);
+      int tgt = register_me(t->tgt, env);
+      printf("blt $%d, $%d, %s\n", src, tgt, stok(t->dst));
+    }
+    if (t->op == APPLY) {
+      int tgt_idx = register_me(t->tgt, env);
+      env->arg_counter = 0;
+      alloc_function_env();
+      printf("sw $fp, 4($v0)\n");
+      if (env->bindings != NULL) {
+        int i = 2;
+        BLIST* ptr = env->bindings;
+        while (ptr != NULL) {
+          if (ptr->binding->name->lexeme[0] != '$') {
+            printf("sw $%d, %d($fp)\n", svd_regs[ptr->binding->env_offset], i*4);
+            i++;
+          }
+          ptr = ptr->next;
+        }
+      }
+      printf("or $fp, $0, $v0\n");
+      printf("la $t0, %s\n", stok(t->dst));
+      printf("sw $t0, 0($fp)\n");
+      printf("jal %s\n", stok(t->dst));
+      printf("lw $fp, 4($fp)\n");
+      printf("lw $ra, 64($fp)\n");
+      if (env->bindings != NULL) {
+        int i = 2;
+        BLIST* ptr = env->bindings;
+        while (ptr != NULL) {
+          if (ptr->binding->name->lexeme[0] != '$') {
+            printf("lw $%d, %d($fp)\n", svd_regs[ptr->binding->env_offset], i*4);
+            i++;
+          }
+          ptr = ptr->next;
+        }
+      }
+      printf("or $%d, $0, $v1\n", tgt_idx);
+    }
+    if (t->op == IDENTIFIER) {
+      printf("%s:\n", stok(t->dst));
+    }
+    if (t->op == VOID) {
+      printf("j %s\n", stok(t->dst));
     }
     if (t->op == RETURN) {
-      int src_idx = alloc_register(t->src);
+      int src_idx = register_me(t->src, env);
       printf("or $v1, $0, $%d\n", src_idx);
+      printf("jr $31\n");
+    }
+    if (t->op == 279) {
+      env = env->previous;
+    }
+    if (t->op == 278) {
+      int dst_idx = register_me(t->dst, env);
+      printf("or $%d, $0, $%d\n", arg_regs[env->arg_counter], dst_idx);
+      env->arg_counter++;
+    }
+    if (t->op == AUTO) {
+      int dst_idx = register_me(t->dst, env);
+      printf("or $%d, $0, $%d\n", dst_idx, arg_regs[env->param_counter]);
+      env->param_counter++;
     }
     tacs = tacs->next;
   }
-  printf("ori $v0, 10\n");
+  printf("done:\n");
+  printf("ori $v0, $0, 10\n");
   printf("syscall\n");
 }
 
 int main(int argc, char** argv)
 {
     NODE* tree;
-    if (argc>1 && strcmp(argv[1],"-d")==0) yydebug = 1;
+    if (argc>1 && strcmp(argv[1],"-d")==0) debug = 1;
     init_symbtable();
     printf("--C COMPILER\n");
     yyparse();

tac/mips.asm

+li $a0, 68
+li $v0, 9
+syscall
+or $fp, $0, $v0
+la $t0, main
+sw $t0, 0($fp)
+sw $0, 4($fp)
+la $ra, done
+j main
+blah:
+sw $ra, 64($fp)
+or $16, $0, $5
+li $8, 3
+or $17, $0, $8
+add $9, $17, $16
+or $v1, $0, $9
+jr $31
+main:
+sw $ra, 64($fp)
+li $10, 4
+or $16, $0, $10
+li $11, 4
+or $5, $0, $11
+li $a0, 68
+li $v0, 9
+syscall
+sw $fp, 4($v0)
+sw $16, 8($fp)
+or $fp, $0, $v0
+la $t0, blah
+sw $t0, 0($fp)
+jal blah
+lw $fp, 4($fp)
+lw $ra, 64($fp)
+lw $16, 8($fp)
+or $12, $0, $v1
+or $17, $0, $12
+li $13, 5
+ble $17, $13, L0
+li $15, 10
+add $14, $16, $15
+or $16, $0, $14
+j L1
+L0:
+li $25, 5
+add $24, $16, $25
+or $16, $0, $24
+L1:
+add $8, $17, $16
+or $v1, $0, $8
+jr $31
+done:
+ori $v0, $0, 10
+syscall

tac/recurse.asm

+li $a0, 68
+li $v0, 9
+syscall
+or $fp, $0, $v0
+la $t0, main
+sw $t0, 0($fp)
+sw $0, 4($fp)
+la $ra, done
+j main
+#func inner_fact
+inner_fact:
+sw $ra, 64($fp)
+#param n
+or $16, $0, $5
+#param a
+or $17, $0, $6
+#if n != 0 then L0
+bne $16, $0, L0
+#ret a
+or $v1, $0, $17
+jr $31
+#L0
+L0:
+#$t1 := n - 1
+li $9, 1
+sub $8, $16, $9
+#$t2 := a * n
+mult $17, $16
+mflo $10
+#arg $t1
+or $5, $0, $8
+#arg $t2
+or $6, $0, $10
+#call inner_fact, $t0
+li $a0, 68
+li $v0, 9
+syscall
+sw $fp, 4($v0)
+sw $16, 8($fp)
+sw $17, 12($fp)
+or $fp, $0, $v0
+la $t0, inner_fact
+sw $t0, 0($fp)
+jal inner_fact
+lw $fp, 4($fp)
+lw $ra, 64($fp)
+lw $16, 8($fp)
+lw $17, 12($fp)
+or $11, $0, $v1
+#ret $t0
+or $v1, $0, $11
+jr $31
+#end inner_fact
+
+#func fact
+fact:
+sw $ra, 64($fp)
+#param n
+or $16, $0, $5
+#arg n
+or $5, $0, $16
+#arg 1
+li $12, 1
+or $6, $0, $12
+#call inner_fact, $t3
+li $a0, 68
+li $v0, 9
+syscall
+sw $fp, 4($v0)
+sw $16, 8($fp)
+or $fp, $0, $v0
+la $t0, inner_fact
+sw $t0, 0($fp)
+jal inner_fact
+lw $fp, 4($fp)
+lw $ra, 64($fp)
+lw $16, 8($fp)
+or $13, $0, $v1
+#ret $t3
+or $v1, $0, $13
+jr $31
+#end fact
+
+#func main
+main:
+sw $ra, 64($fp)
+#arg 3
+li $14, 3
+or $5, $0, $14
+#call fact, $t4
+li $a0, 68
+li $v0, 9
+syscall
+sw $fp, 4($v0)
+or $fp, $0, $v0
+la $t0, fact
+sw $t0, 0($fp)
+jal fact
+lw $fp, 4($fp)
+lw $ra, 64($fp)
+or $15, $0, $v1
+#x := $t4
+or $16, $0, $15
+#arg 5
+li $24, 5
+or $5, $0, $24
+#call fact, $t5
+li $a0, 68
+li $v0, 9
+syscall
+sw $fp, 4($v0)
+sw $16, 8($fp)
+or $fp, $0, $v0
+la $t0, fact
+sw $t0, 0($fp)
+jal fact
+lw $fp, 4($fp)
+lw $ra, 64($fp)
+lw $16, 8($fp)
+or $25, $0, $v1
+#y := $t5
+or $17, $0, $25
+#arg 7
+li $8, 7
+or $5, $0, $8
+#call fact, $t6
+li $a0, 68
+li $v0, 9
+syscall
+sw $fp, 4($v0)
+sw $16, 8($fp)
+sw $17, 12($fp)
+or $fp, $0, $v0
+la $t0, fact
+sw $t0, 0($fp)
+jal fact
+lw $fp, 4($fp)
+lw $ra, 64($fp)
+lw $16, 8($fp)
+lw $17, 12($fp)
+or $9, $0, $v1
+#z := $t6
+or $18, $0, $9
+#$t8 := x + y
+add $10, $16, $17
+#$t7 := $t8 + z
+add $11, $10, $18
+#ret $t7
+or $v1, $0, $11
+jr $31
+#end main
+
+done:
+ori $v0, $0, 10
+syscall

tac/recursion.c

+/* ##answer: 5166*/
+
+
+int inner_fact(int n, int a) {
+  if (n == 0) return a;
+  return inner_fact(n-1, a*n);
+}
+
+int fact(int n) {
+  return inner_fact(n, 1);
+}
+
+int main() {
+  int x = fact(3);
+  int y = fact(5);
+  int z = fact(7);
+
+  return x+y+z;
+}

tac/simple.c

-int inner_fact(int n, int a) {
-  if (n == 0) return a;
-  return inner_fact(n-1, a*n);
-}
-
-int fact(int n) {
-  return inner_fact(n, 1);
+int blah(int b) {
+  int y = 3;
+  return y + b;
 }
 
 int main() {
-  int x = blah(2);
-  if (x > 0) {
-    x = 10;
+  int y = 4;
+  int x = blah(4);
+  if (x > 5) {
+    y = y+10;
   } else {
-    x = 5;
+    y = y+5;
   }
-  return x;
+  return x+y;
 }

tac/test.asm

+j main
+blah:
+ori $8, $0, 6
+or $v1, $0, $8
+jr $31
 main:
-ori $8, $0, 2
-li $9, 48282
-add $19, $9, $8
-ori $10, $0, 2
-mult $19, $10
-mflo $20
-ori $11, $0, 2
-ori $12, $0, 4
-div $12, $11
-mflo $21
-ori $13, $0, 5
-div $13, $21
-mfhi $22
-sub $23, $20, $22
-or $k0, $0, $23
+la $31 done
+sw $31, 0($sp)
+jal blah
+nop
+lw $31, 0($sp)
+or $9, $0, $v1
+or $16, $0, $9
+ori $10, $0, 5
+ble $16, $10, L0
+ori $11, $0, 10
+or $17, $0, $11
+j L1
+L0:
+ori $12, $0, 5
+or $18, $0, $12
+L1:
+or $v1, $0, $18
+jr $31
+done:
 ori $v0, 10
 syscall

tac/types.h

 #include "nodes.h"
 
 typedef struct binding {
-  char* name;
-  NODE* tree;
+  TOKEN* name;
+  int env_offset;
+  int is_saved;
   struct environ *env;
 } BIND;
 
 } BLIST;
 
 typedef struct environ {
+  int return_addr;
   BLIST *bindings;
   struct environ *parent;
+  struct environ *previous;
+  int counter;
+  int param_counter;
+  int arg_counter;
 } ENV;
 
 typedef struct tac_elem {