M projects/06/assembler1/assembler1.c → projects/06/assembler1/assembler1.c

@@ -7,9 +7,10 @@ 
 #include "../bindump.h"
 
 #define DEBUG(...)              printf(__VA_ARGS__)
+#define die(err_msg)            perror(err_msg); exit(-1)
+#define alert(...)              fprintf(stderr, __VA_ARGS__)
 
-#define die(err_msg, exit_val)  perror(err_msg); exit(exit_val)
-#define alert(...)              fprintf(stderr, __VA_ARGS__)
+#define MAX_LINE_LEN            256
 
 
 uint32_t myatoi(const char *a_field_str)
@@ -35,12 +36,12 @@ alert("error: A-type instruction doesn't start with @\n");
 		return false;
 	}
 
-	if (line[1] == '\n') {
+	if (line[1] == '\0') {
 		alert("error: A-type instruction empty after @\n");
 		return false;
 	}
 
-	for (i = 1; (c = line[i]) != '\n' && a < 6; ++i) {
+	for (i = 1; (c = line[i]) != '\0' && a < 6; ++i) {
 		if ('0' <= c && c <= '9') {
 			if (a > 4) {
 				alert("error: @<number> too long\n");
@@ -72,6 +73,8 @@ }
 
 bool parse_c_type(const char *line, uint16_t *instruction)
 {
+	// Note: could do 'jump' fields via lookup tables once
+	// they're extracted from the line
 	*instruction = 0x8888; // STUB, TODO implement
 	return true;
 }
@@ -84,7 +87,7 @@ bool ret;
 	char c;
 	size_t i = 0;
 
-	while ((c = line[i]) != '\n') {
+	while ((c = line[i]) != '\0') {
 		if (c == ' ' || c == '\t')
 			;  // skip any whitespace at start of line
 		else if (c == '@') {
@@ -143,46 +146,49 @@ // comment not found, so attempting to parse instruction
 	return parse_next_instruction(line, instruction);
 }
 
-const char *test_lines[] = {"// this is a comment\n",               // line 1
-			    "@12345\n",                             // line 2
-			    "\n",                                   // line 3
-                            "M+1\n",                                // line 4
-                            "@98 // test comment\n",                // line 5
-                            "// this is another comment\n",         // line 6
-                            "/ this is a broken comment\n",         // line 7
-                            "D=M;JNE\n",                            // line 8
-			    "   @1337// immediate comment \n",      // line 9
-			    "\t@44441337 // number too long \n",    // line 10
-			    " \t @1     // 1\n",                    // line 11
-			    "\t @2      // 2\n",                    // line 12
-			    "\t @3\n",                              // line 13
-			    "\t @4\n",                              // line 14
-			    " \t@5      // 3\n",                    // line 15
-			    "    @6     // 4\n",                    // line 16
-			    "\t @7\n",                              // line 17
-			    "    @0x1337 // invalid char in num\n"}; // line 18
-size_t num_test_lines = (sizeof(test_lines) / sizeof(test_lines[0]));
+
+char *usage_msg = "Usage: assembler1 [path/to/file.asm]\n";
 
-int main()
+int main(int argc, char *argv[])
 {
-	// TODO: read file by lines, parse instructions
 	bool result = false; 
 	uint16_t instruction;
-	size_t test_line_len;
+	char in_line[MAX_LINE_LEN];
+	size_t in_line_len, i, count;
+	char *in_file_path;
+	FILE *fp;
+
+	if (argc != 2) {                            // requires 1 argument
+		die(usage_msg);
+		exit(-1);
+	}
+
+	in_file_path = argv[1];
+	fp = fopen(in_file_path, "r");
+	if (fp == NULL) {
+		die("failed to open file for reading\n");
+		exit(-1);
+	}
+
+	count = 1;
+	while (fgets(in_line, MAX_LINE_LEN, fp) != NULL) {
+		in_line_len = strlen(in_line);
 
-	// New organization allows code to eventually work with lines fetched
-	// from a 'fgets()' loop or something
+		for (i = 0; i < in_line_len; ++i) { // remove newlines
+			if (in_line[i] == '\n') {
+				in_line[i] = '\0';
+				break;
+			}
+		}
 
-	// for testing
-	for (size_t i = 0; i < num_test_lines; ++i) {
-		DEBUG("%lu|%s", i+1, test_lines[i]);
-		test_line_len = strlen(test_lines[i]);
-		result = parse_line(test_lines[i], test_line_len, &instruction);
+		DEBUG("%lu|%s\n", count, in_line);
+		result = parse_line(in_line, in_line_len, &instruction);
 		if (result) {
 			DEBUG("instruction: 0x%x  |  ", instruction);
 			bindump_word16(instruction); // output instruction as binary
 			putchar('\n');
 		}
+	++count;
 	}
 
 	return 0;