From ca79377e3ea2201c076dea92ce001b65481af90e Mon Sep 17 00:00:00 2001
From: Veit Heller <veit.heller@student.htw-berlin.de>
Date: Tue, 7 Oct 2014 13:29:01 +0200
Subject: [PATCH] Added documentation to nbfi

---
 nbfi/src/nbfi.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 54 insertions(+), 2 deletions(-)

diff --git a/nbfi/src/nbfi.c b/nbfi/src/nbfi.c
index 9ae08c5..2e40ab7 100644
--- a/nbfi/src/nbfi.c
+++ b/nbfi/src/nbfi.c
@@ -1,39 +1,79 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+/*end instruction*/
 #define END 0
+/*increment pointer instruction, equivalent to > */
 #define INC_DP 1
+/*decrement pointer instruction, equivalent to < */
 #define DEC_DP 2
+/*increment value instruction, equivalent to + */
 #define INC_VAL 3
+/*decrement value instruction, equivalent to - */
 #define DEC_VAL 4
+/*output value instruction, equivalent to . */
 #define OUT 5
+/*input value instruction, equivalent to , */
 #define IN 6
+/*jump forward instruction, equivalent to [ */
 #define JMP_FWD 7
+/*jump back instruction, equivalent to ] */
 #define JMP_BCK 8
 
+/*Maximum program size*/
 #define PROGRAM_SIZE 1048576
+/*Maximum stack size*/
 #define MAX_SIZE 5024291
+/*Maximum data size*/
 #define DATA_SIZE 1638375
 
+/*Push macro, implements stack operation push*/
 #define PUSH(A) (stack[sp++] = A)
+/*Pop macro, implements stack operation pop*/
 #define POP() (stack[--sp])
+/*Empty macro, implements stack operation check if empty*/
 #define EMPTY() (sp == 0)
+/*Full macro, implements stack operation check if full*/
 #define FULL() (sp == MAX_SIZE)
 
+
+/**
+ * @brief die
+ * @param code -> the error code
+ * @param message -> the error message
+ *
+ * Lets the program die and emits an error message.
+ */
 static inline void die(int code, const char* message){
     fprintf(stderr, "%s", message);
     exit(code);
 }
 
+/** 
+ * @brief An instruction struct
+ *
+ * Consists of operator and operand,
+ * the easiest way of abstracting
+ * an instruction.
+ */
 struct instruction{
-    unsigned int operator;
-    unsigned int operand;
+    unsigned int operator; ///< Operator
+    unsigned int operand; ///< Operand
 };
 
+/*The program as an array of structs*/
 static struct instruction program[PROGRAM_SIZE];
+/*The stack*/
 static unsigned int stack[MAX_SIZE];
+/*The stack pointer*/
 static unsigned long sp = 0;
 
+/**
+ * @brief compile
+ * @param fp -> the file
+ *
+ * Compiles a file to bytecode and saves that within program.
+ */
 void compile(FILE* fp){
     unsigned int pc = 0, jmp_pc;
     int ip;
@@ -74,6 +114,11 @@ void compile(FILE* fp){
     program[pc].operator = END;
 }
 
+/**
+ * @brief execute
+ *
+ * Executes the bytecode within program.
+ */
 void execute(){
     unsigned int data[DATA_SIZE], pc = 0;
     unsigned int ptr = DATA_SIZE;
@@ -96,6 +141,13 @@ void execute(){
         die(127, "nbfi:execute: Program used up too much memory.\n");
 }
 
+/*
+ * @brief main
+ * @param argc -> argument counter
+ * @param argv -> argument vector
+ * 
+ * compiles and executes brainfuck code from a file.
+ */
 int main(int argc, const char * argv[]){
     FILE *fp;
     if(argc != 2)