M projects/06/assembler2/assembler2.c → projects/06/assembler2/assembler2.c

@@ -140,13 +140,64 @@ 
 	return add_symbol(label_str, (uint16_t)instruction_offset);
 }
 
+bool parse_c_type_dest(const char *dest_line, uint16_t *dest)
+{
+	// also length check here since it's not being done in parse_c_type()
+	*dest = 0x05;
+	return true;
+}
+
+bool parse_c_type_comp(const char *comp_line, uint16_t *comp)
+{
+	// also length check here since it's not being done in parse_c_type()
+	*comp = 0x32;
+	return true;
+}
+
+bool parse_c_type_jump(const char *jump_line, uint16_t *jump)
+{
+	// also length check here since it's not being done in parse_c_type()
+	*jump = 3;
+	return true;
+}
+
 bool parse_c_type(const char *line, uint16_t *instruction)
 {
-	DBGLOG("C-type, offset %lu, line %lu | %s\n", instruction_offset,
+	size_t i;
+	char c;
+	const char *dest_start = NULL, *comp_start = NULL, *jump_start = NULL;
+	uint16_t dest = 0, comp = 0, jump = 0; // TODO: remove, just use instruction
+
+	c = line[0];
+	for (i = 0; !is_whitespace(c) && c != '\n' && c != '\0'; ++i) {
+		c = line[i];
+		if (c == '=') {
+			dest_start = &line[0];
+			comp_start = &line[i+1];
+		} else if (c == ';')
+			jump_start = &line[i+1];
+	}
+
+	DBGLOG("C-type, offset %lu, line %lu | %s \n", instruction_offset,
 	       file_line_no, line);
-	uint16_t val = 0xb9c3;
-	*instruction = val;
-	return true; // STUB TODO remove me
+
+	// only comp field is mandatory; dest/jump are optional, may not exist
+	if (comp_start == NULL)
+		comp_start = &line[0];
+
+	if (!parse_c_type_comp(comp_start, &comp))
+		return false;
+
+	if (dest_start != NULL)
+		if (!parse_c_type_dest(dest_start, &dest))
+			return false;
+
+	if (jump_start != NULL)
+		if (!parse_c_type_jump(jump_start, &jump))
+			return false;
+
+	*instruction = 0xe000 | (comp << 6) | (dest << 3) | jump;
+	return true;
 }
 
 bool parse_a_type(const char *line, uint16_t *instruction)