Implement FPGA as target device into compiler

bfpcompiler/src/assembling.c

@@ -1,5 +1,125 @@
 #include "../include/assembling.h"
 
+/**
+ *	@name intoVHDL
+ *	@return static char*
+ *  @brief Return binary as VHDL code.
+ *
+ *	@param char* tokens
+ */
+static char* intoVHDL (char* tokens) {
+    char* binary = 0;
+
+    /* The maximum size would be 256 instructions wide.
+     *  'b"000",' => one instruction has the length 7 which adds up to 256 * 7 = 1792 at max.
+     *  The declaration is wrapped in (code); which adds another 3 to the length.
+     *  At the end, the remaining registers are set to zero with 'others=>"000"', so another 13 characters are added:
+     *  Finally, the string must be terminated by '\0' (+1).
+     *  The buffer size is 1792 + 3 + 13 + 1 = 1809.
+     */
+    int binary_size = 1809;
+    int pos = 0; /* cursor to navigate the buffer. */
+
+    /* Allocate memory for binary */
+    binary = (char*)malloc(sizeof(char) * binary_size);
+    if (!binary) {
+        /* Error */
+        perror("malloc error on memory allocation of: binary");
+        exit(EXIT_FAILURE);
+    }
+
+    /* insert first bracket */
+    binary[pos++] = '(';
+
+    /* insert tokens */
+    for (int token = 0; tokens[token]; token++) {
+
+        /* check if maximum amount of 256 instructions is violated */
+        if (token > 256) {
+            (void)printf("ERROR: More instructions than possible!\n");
+            exit(EXIT_FAILURE);
+        }
+
+        binary[pos++] = 'b';
+        binary[pos++] = '"';
+
+        switch (tokens[token]) {
+            case '>':
+                binary[pos++] = '0';
+                binary[pos++] = '0';
+                binary[pos++] = '0';
+                break;
+            case '<':
+                binary[pos++] = '0';
+                binary[pos++] = '0';
+                binary[pos++] = '1';
+                break;
+            case '+':
+                binary[pos++] = '0';
+                binary[pos++] = '1';
+                binary[pos++] = '0';
+                break;
+            case '-':
+                binary[pos++] = '0';
+                binary[pos++] = '1';
+                binary[pos++] = '1';
+                break;
+            case ',':
+                binary[pos++] = '1';
+                binary[pos++] = '0';
+                binary[pos++] = '0';
+                break;
+            case '.':
+                binary[pos++] = '1';
+                binary[pos++] = '0';
+                binary[pos++] = '1';
+                break;
+            case '[':
+                binary[pos++] = '1';
+                binary[pos++] = '1';
+                binary[pos++] = '0';
+                break;
+            case ']':
+                binary[pos++] = '1';
+                binary[pos++] = '1';
+                binary[pos++] = '1';
+                break;
+            default:
+                (void)printf("ERROR: Unknown token %c (%d)!\n", token, token);
+                exit(EXIT_FAILURE);
+        }
+
+        binary[pos++] = '"';
+        binary[pos++] = ',';
+
+    }
+
+    /* This is the closing term. */
+    binary[pos++] = '(';
+    binary[pos++] = 'o';
+    binary[pos++] = 't';
+    binary[pos++] = 'h';
+    binary[pos++] = 'e';
+    binary[pos++] = 'r';
+    binary[pos++] = 's';
+    binary[pos++] = '=';
+    binary[pos++] = '>';
+    binary[pos++] = '\'';
+    binary[pos++] = '0';
+    binary[pos++] = '\'';
+    binary[pos++] = ')';
+
+    /* Close initial memory. */
+    binary[pos++] = ')';
+    binary[pos++] = ';';
+
+    /* Terminate string */
+    binary[pos++] = 0;
+
+    return binary;
+}
+
+
 /**
  *	@name intoLogisim
  *	@return static char*
@@ -88,7 +208,9 @@ char* assemble (char* device, char* tokens) {
     /* supported devices are hardcoded here. */
     if (!strcmp(device, "logisim")) {
         rv = intoLogisim(tokens);
-    }else {
+    } else if (!strcmp(device, "FPGA")) {
+        rv = intoVHDL(tokens);
+    } else {
         (void)printf("ERROR: Chosen device %s does not exist!\n", device);
         rv = (char*)EXIT_FAILURE;
     }