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

@@ -13,7 +13,7 @@ 
 #define is_symbol_char(c) (('0' <= c && c <= '9') || ('A' <= c && c <= 'Z') \
                         || ('a' <= c && c <= 'z') || c == '_' || c == '.'   \
                                                   || c == '$' || c == ':')
-#define is_whitespace(c) ((c == ' ' || c == '\t'))
+#define is_whitespace(c) ((c == ' ' || c == '\t' || c == '\n'))
 #define is_number(c) (('0' <= c && c <= '9'))
 
 #define MAX_LINE_LEN          256 // TODO: in/excludes NULL terminator?
@@ -140,18 +140,20 @@ 
 	return add_symbol(label_str, (uint16_t)instruction_offset);
 }
 
-bool parse_c_type_dest(const char *dest_line, uint16_t *dest)
+/* returns dest bits 0b00000ddd
+ */
+bool parse_c_type_dest(const char *line, uint16_t *dest)
 {
 	size_t i;
 	uint8_t a_dest = 0, d_dest = 0, m_dest = 0;
 
-	for (i = 0; dest_line[i] != '='; ++i) {
-		switch (dest_line[i]) {
+	for (i = 0; line[i] != '='; ++i) {
+		switch (line[i]) {
 		case 'A': ++a_dest; break;
 		case 'D': ++d_dest; break;
 		case 'M': ++m_dest; break;
-		default: return  err("error: invalid destination register "
-			               "'%c'\n", dest_line[i]);
+		default: return  err("syntax error: invalid destination "
+			               "register '%c'\n", line[i]);
 		}
 
 		if (i >= 3)
@@ -159,39 +161,61 @@ return err("error: too many destinations\n");
 	}
 
 	if (a_dest > 1)
-		return err("err: multiple 'A's found in destination\n");
+		return err("syntax error: multiple 'A's in destination\n");
 	if (d_dest > 1)
-		return err("err: multiple 'D's found in destination\n");
+		return err("syntax error: multiple 'D's in destination\n");
 	if (m_dest > 1)
-		return err("err: multiple 'M's found in destination\n");
+		return err("syntax error: multiple 'M's in destination\n");
 
 	*dest = (uint16_t)((a_dest << 2) | (d_dest << 1) | (m_dest));
 	return true;
 }
 
-bool parse_c_type_comp(const char *comp_line, uint16_t *comp)
+/* returns comp bits 0b0acccccc
+ */
+bool parse_c_type_comp(const char *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)
+/* returns jump bits 0b00000jjj
+ */
+bool parse_c_type_jump(const char *line, uint16_t *jump)
 {
-	// also length check here since it's not being done in parse_c_type()
-	*jump = 3;
-	return true;
+	size_t i;
+	char jump_str[5];
+	char *jump_tb[] = {"", "JGT", "JEQ", "JGE", "JLT", "JNE", "JLE", "JMP"};
+
+	for (i = 0; i < 5 && !is_whitespace(line[i]) && line[i] != '/'; ++i)
+		jump_str[i] = line[i];
+
+	jump_str[i] = '\0';
+	if (i > 4)
+		return err("syntax error: invalid jump field '%s'\n", jump_str);
+
+	for (i = 0; i < (sizeof(jump_tb) / sizeof(jump_tb[0])); ++i) {
+		if (strncmp(jump_tb[i], jump_str, 3) == 0) {
+			*jump = (uint16_t)i;
+			return true;
+		}
+	}
+
+	return err("syntax error: invalid jump field '%s'\n", jump_str);
 }
 
+/* instruction format: 0b111accccccdddjjj
+ */
 bool parse_c_type(const char *line, uint16_t *instruction)
 {
 	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
+	uint16_t dest = 0, comp = 0, jump = 0;
 
 	c = line[0];
-	for (i = 0; !is_whitespace(c) && c != '\n' && c != '\0'; ++i) {
+	for (i = 0; !is_whitespace(c) && c != '\0'; ++i) {
 		c = line[i];
 		if (c == '=') {
 			dest_start = &line[0];