Addition to proof of correctness

bfpcompiler/proof.md

@@ -82,4 +82,65 @@ are implemented memory safe.
 
 ## Every program, which is accepted by the compiler without error is working on the processor.
 
+The 8 operators of brainfuck can be divided into two different groups:
+
+- < > + - , .
+- [  ]
+
+The operators of the first group can be used
+
+- in any order
+- with any amount
+
+Following those conditions, there is no need for a syntax check, as every order is a valid program.
+
+This is different with the second group, which holds the loop operators.
+Those need to
+
+- be included in a certain order: [  ]
+- be included in the code with the same amount: $w_[ = w_]$
+
+The code must be checked for the right amount and order of loop operators.
+This is done by using the following code:
+```c
+for (char* cursor = token; *cursor; cursor++) {
+
+    /* Analyze form */
+    if (*cursor == '[') {
+        rv += 1;
+    } else if (*cursor == ']') {
+        rv -= 1;
+    }
+
+    /* Check value for errors. */
+    if (rv < 0) {
+        (void)printf("ERROR!\n");
+        rv = EXIT_FAILURE;
+        break;
+    }
+
+    /* check for nested loops */
+    if (rv > 1) {
+        (void)printf("WARNING!\n");
+    }
+}
+
+if (rv > 0) {
+    (void)printf("ERROR!\n");
+    rv = EXIT_FAILURE;
+}
+```
+
+The value of rv is checked for the following conditions:
+
+|Condition|Reaction|Description|
+|---------|--------|-----------|
+| $<0$    |ERROR   |A closing bracket is ending a non-existing loop. There is no address to jump back to.|
+| $>2$    |WARNING |A nested bracket is opened. Although this is not wrong for brainfuck, my circuit does currently not support this.|
+| $>0$    |ERROR   |This is checked after the loop. If the value of rv is greater than zero, a bracket was not closed.|
+
+The last check maybe could be handled as warning, because the program can be run in a loop, even if it would never end.
+
+By doing this check on the given program, it's safe to assume, that every program, that is accepted by the compiler, can be run.
+
 ## The compiled binaries are working the same way as the provided code.

bfpcompiler/src/assembling.c

@@ -74,6 +74,86 @@ static char* intoLogisim (char* tokens) {
     return binary;
 }
 
+/**
+ *	@name intoC
+ *	@return static char*
+ *  @brief Return binary as c file.
+ *
+ *	@param char* tokens
+ */
+static char* intoC (char* tokens) {
+
+    return 0;
+
+    char* binary = 0;
+
+    /* TODO: Change size to match C language */
+    /* Using c 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);
+    }
+
+    /* TODO: Replace by C program */
+    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++) {
+
+        /* TODO: Replace by C thingies */
+        /* 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*
@@ -88,7 +168,9 @@ char* assemble (char* device, char* tokens) {
     /* supported devices are hardcoded here. */
     if (!strcmp(device, "logisim")) {
         rv = intoLogisim(tokens);
-    } else {
+    } else if (!strcmp(device, "c")) {
+        rv = intoClang(tokens);
+    }else {
         (void)printf("ERROR: Chosen device %s does not exist!\n", device);
         rv = (char*)EXIT_FAILURE;
     }