From e16553d93b1acc1771ac3429042c2e8759f7e656 Mon Sep 17 00:00:00 2001
From: Veit Heller <veit.heller@student.htw-berlin.de>
Date: Sun, 21 Dec 2014 12:31:10 +0100
Subject: [PATCH] Replaced opcode defines with enum

---
 src/opcode.h | 56 +++++++++++++++++++++++++++-------------------------
 src/vm.c     | 17 +++++++++++++---
 2 files changed, 43 insertions(+), 30 deletions(-)

diff --git a/src/opcode.h b/src/opcode.h
index f064ac7..7807abd 100644
--- a/src/opcode.h
+++ b/src/opcode.h
@@ -1,59 +1,61 @@
 #ifndef OPCODE_H
 #define OPCODE_H
+enum {
 /*Addition operation*/
-#define IADD 1
+    IADD = 1,
 /*Subtraction operation*/
-#define ISUB 2
+    ISUB,
 /*Multiplication operation*/
-#define IMULT 3
+    IMULT,
 /*Division operation*/
-#define IDIV 4
+    IDIV,
 /*Modulo operation*/
-#define IMOD 5
+    IMOD,
 /*< operation*/
-#define ILT 6
+    ILT,
 /*== operation*/
-#define IEQ 7
+    IEQ,
 /*> operation*/
-#define IGT 8
+    IGT,
 /*branch operation*/
-#define BR 9
+    BR,
 /*branch if true operation*/
-#define BRT 10
+    BRT,
 /*branch if false operation*/
-#define BRF 11
+    BRF,
 /*put operation*/
-#define ICONST 12
+    ICONST,
 /*load variable operation*/
-#define LOAD 13
+    LOAD,
 /*load global variable operation*/
-#define GLOAD 14
+    GLOAD,
 /*store variable operation*/
-#define STORE 15
+    STORE,
 /*store global variable operation*/
-#define GSTORE 16
+    GSTORE,
 /*print operation*/
-#define PRINT 17
+    PRINT,
 /*pop operation*/
-#define POP 18
+    POP,
 /*end/halt operation*/
-#define HALT 19
+    HALT,
 /*<= operation*/
-#define ILEQ 20
+    ILEQ,
 /*>= operation*/
-#define IGEQ 21
+    IGEQ,
 /*call subroutine operation*/
-#define CALL 22
+    CALL,
 /*return from subroutine operation*/
-#define RET 23
+    RET,
 /*print integer operation*/
-#define IPRINT 24
+    IPRINT,
 /*fetch operation*/
-#define FETCH 25 
+    FETCH,
 /*++ operation*/
-#define IINC 26
+    IINC,
 /*-- operation*/
-#define IDEC 27 
+    IDEC
+};
 
 /**
  * @brief An instruction struct
diff --git a/src/vm.c b/src/vm.c
index 71827f6..4af3032 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -33,7 +33,9 @@ void vm_execute(int code[], int ip, int datasize, unsigned long length){
         register int sp = -1;
         register int fp = -1;
         int nargs, addr, a, b;
+        
         instruction* ins = setup_instructions();
+        
         while(ip < length){
             int opcode = code[ip];
             ip++;
@@ -168,6 +170,7 @@ program vm_compile(char *filename){
     char** command = NULL;
     unsigned long size = 100;
     int* code = malloc(size * sizeof(int));
+    int* code_realloc = NULL;
     unsigned long codep = 0;
     register int i;
     instruction* ins = setup_instructions();
@@ -187,9 +190,13 @@ program vm_compile(char *filename){
 
         if(codep == size){
             size += 100;
-            code = (int *) realloc(code, size * sizeof(int));
-            if(code == NULL)
+            code_realloc = (int *) realloc(code, size * sizeof(int));
+            if(code_realloc == NULL){
+                free(code);
                 die(127, "Program too big, could not allocate enough storage.");
+            }
+            code = code_realloc;
+            code_realloc = NULL;
         }
 
         if(strcmp(command[0], "ENTRY") == 0){
@@ -231,7 +238,11 @@ program vm_compile(char *filename){
     if(line)
         free(line);
 
-    code = (int *) realloc(code, codep * sizeof(int));
+    code_realloc = (int *) realloc(code, codep * sizeof(int));
+    if(code_realloc != NULL){
+        code = code_realloc;
+        code_realloc = NULL;
+    }
     
     prog.length = codep;
     prog.entrypoint = entry;