hack-as: Dynamic memory allocation

1 files changed, 13 insertions, 4 deletions

diff --git a/projects/06/hack-as/hack-as.c b/projects/06/hack-as/hack-as.c
index 6dde75d..b152fb8 100644
--- a/projects/06/hack-as/hack-as.c
+++ b/projects/06/hack-as/hack-as.c
@@ -5,6 +5,7 @@
 #include <string.h>
 
 #define MAX_ASM_LINE_LEN	64
+#define INST_CHUNK_LEN		64
 #define MAX_INST_LEN		32768
 #define MAX_ADDR		32767
 
@@ -195,7 +196,7 @@ size_t assembler(char *input_fn, bool verbose) {
 	// resulting in lines of what looks like instructions in assembly but is not necessarily correct
 	// labels in parentheses are assigned corresponding addresses in ROM, then collected in `symbols`
 	// the strings are scattered in the heap but asm_lines collects pointers to them
-	char *asm_lines[MAX_INST_LEN] = {NULL};
+	char **asm_lines = calloc(INST_CHUNK_LEN, sizeof(char*));
 	int asm_line_cnt = 0;	// no. of lines (metaphorically) written into asm_lines
 	char *asm_line = malloc(MAX_ASM_LINE_LEN + 1);	// one line of (probably) assembly
 	int asm_char_cnt = 0;		// no. of chars written into asm_line
@@ -230,13 +231,17 @@ size_t assembler(char *input_fn, bool verbose) {
 				symbols[predef_symbol_cnt + user_symbol_cnt] = (struct symbol) {label, asm_line_cnt};
 				user_symbol_cnt++;
 			} else {
-				// this line may be an instruction; assemble it
+				// this line may be an instruction
+				// if we used up a chunk, realloc asm_lines
+				if (asm_line_cnt > 0 && asm_line_cnt % INST_CHUNK_LEN == 0) {
+					asm_lines = realloc(asm_lines, (asm_line_cnt + INST_CHUNK_LEN) * sizeof(char*));
+				}
 				asm_lines[asm_line_cnt] = asm_line;
 				asm_line_cnt++;
 			}
 			// allocate memory for next line
 			asm_char_cnt = 0;
-			asm_line = malloc(MAX_ASM_LINE_LEN);
+			asm_line = malloc(MAX_ASM_LINE_LEN + 1);
 			break;
 		case '/':
 			if (i + 1 < file_size && file_content[i + 1] == '/') {
@@ -282,7 +287,10 @@ size_t assembler(char *input_fn, bool verbose) {
 				is_symbol = true;
 			}
 		}
-		if (!is_symbol) continue;	// address is decimal constant
+		if (!is_symbol) {
+			free(addr_str);
+			continue;	// address is decimal constant
+		}
 		char illegal_char = find_illegal_symbol_char(addr_str);
 		if (illegal_char != -1) {
 			fprintf(stderr, "Illegal character: %c\n", illegal_char);
@@ -327,6 +335,7 @@ size_t assembler(char *input_fn, bool verbose) {
 	}
 
 	for (char **line = asm_lines; *line != NULL; line++) free(*line);
+	free(asm_lines);
 	for (int s = predef_symbol_cnt; s < predef_symbol_cnt + user_symbol_cnt; s++) {
 		free(symbols[s].label);
 	}