From 451c6406c23047947376650c0d1188e491b45907 Mon Sep 17 00:00:00 2001
From: yannickreiss <yannick.reiss@protonmail.ch>
Date: Fri, 22 Sep 2023 15:12:17 +0200
Subject: [PATCH] Add functions to compile programs for logisim

---
 bfpcompiler/include/assembling.h | 12 ++++
 bfpcompiler/src/assembling.c     | 96 ++++++++++++++++++++++++++++++++
 2 files changed, 108 insertions(+)

diff --git a/bfpcompiler/include/assembling.h b/bfpcompiler/include/assembling.h
index e225898..2c1d8c1 100644
--- a/bfpcompiler/include/assembling.h
+++ b/bfpcompiler/include/assembling.h
@@ -1,6 +1,18 @@
 #ifndef ASSEMBLING_H
 #define ASSEMBLING_H
 
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
 
+/**
+ *	@name assemble
+ *	@return char*
+ *	@brief Assemble into binary for chosen device. Returns pointer on success, zero on error.
+ *
+ *	@param char* device:	assemble_device
+ *	@param char* tokens:	assemble_tokens
+ */
+char* assemble (char* device, char* tokens);
 
 #endif//ASSEMBLING_H
diff --git a/bfpcompiler/src/assembling.c b/bfpcompiler/src/assembling.c
index 622e0ec..b61fa82 100644
--- a/bfpcompiler/src/assembling.c
+++ b/bfpcompiler/src/assembling.c
@@ -1 +1,97 @@
 #include "../include/assembling.h"
+
+/**
+ *	@name intoLogisim
+ *	@return static char*
+ *  @brief Return binary as logisim file.
+ *
+ *	@param char* tokens
+ */
+static char* intoLogisim (char* tokens) {
+    char* binary = 0;
+
+    /* Using logisim with the current memory space (256x4) has the fixed size of 533 bytes. */
+    int filesize = 533;
+    int pos = 0; /* used to navigate around binary */
+
+    /* Allocate memory for binary */
+    binary = (char*)malloc(sizeof(char) * filesize);
+    if (!binary) {
+        /* Error */
+        perror("malloc error on memory allocation of: binary");
+        exit(EXIT_FAILURE);
+    }
+
+    char version_number[] = "v3.0 hex words plain";
+    for (int i = 0; i < 20; i++) {
+        binary[i] = version_number[i];
+    }
+    pos = 20; /* position after loop */
+
+    binary[pos++] = '\n';
+
+    int pos_space = pos + 1; /* save the index to fill with spaces here */
+
+    /* Loop through tokens and add matching code to binary. */
+    for (char* cursor = tokens; *cursor; cursor++) {
+
+        /* Switch case holds all operands. */
+        switch (*cursor) {
+            case '>': binary[pos] = '0';break;
+            case '<': binary[pos] = '1';break;
+            case '+': binary[pos] = '2';break;
+            case '-': binary[pos] = '3';break;
+            case ',': binary[pos] = '4';break;
+            case '.': binary[pos] = '5';break;
+            case '[': binary[pos] = '6';break;
+            case ']': binary[pos] = '7';break;
+            default: return (char*)EXIT_FAILURE;
+        }
+
+        /* every second position is space or newline */
+        pos += 2;
+    }
+
+    /* fill remaining instruction space with > operations */
+    for (; pos < filesize; pos += 2) {
+        binary[pos] = '0';
+    }
+
+    /* reset position to the first space and start filling up */
+    pos = pos_space;
+    for (; pos < filesize; pos += 2) {
+        /* Calculate whether to use space or newline. */
+        if ((pos - 20) % 64 == 0) {
+            binary[pos] = '\n';
+        } else {
+            binary[pos] = ' ';
+        }
+    }
+
+    /* Finally, end the string. */
+    binary[filesize-1] = '\n';
+
+    return binary;
+}
+
+/**
+ *	@name assemble
+ *	@return char*
+ *  @brief Assemble tokens into binary for chosen device.
+ *
+ *	@param char* device
+ *	@param char* tokens
+ */
+char* assemble (char* device, char* tokens) {
+    char* rv = 0;
+
+    /* supported devices are hardcoded here. */
+    if (!strcmp(device, "logisim")) {
+        rv = intoLogisim(tokens);
+    } else {
+        (void)printf("ERROR: Chosen device %s does not exist!\n", device);
+        rv = (char*)EXIT_FAILURE;
+    }
+
+    return rv;
+}