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-rw-r--r--projects/06/hack-as/hack-as.c384
1 files changed, 0 insertions, 384 deletions
diff --git a/projects/06/hack-as/hack-as.c b/projects/06/hack-as/hack-as.c
deleted file mode 100644
index b152fb8..0000000
--- a/projects/06/hack-as/hack-as.c
+++ /dev/null
@@ -1,384 +0,0 @@
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <stdbool.h>
-#include <string.h>
-
-#define MAX_ASM_LINE_LEN 64
-#define INST_CHUNK_LEN 64
-#define MAX_INST_LEN 32768
-#define MAX_ADDR 32767
-
-#define EXIT_CODE_FILE_ERROR 1
-#define EXIT_CODE_ILLEGAL_CHAR 2
-#define EXIT_CODE_SIZE_EXCEEDED 3
-#define EXIT_CODE_SYNTAX_ERROR 4
-#define EXIT_CODE_ADDR_ERROR 5
-
-struct symbol {
- char *label;
- int addr;
-};
-
-char find_illegal_symbol_char(char *symbol) {
- // symbol should not begin with number
- // nand2tetris implementation allows it, but the standard says otherwise
- if (*symbol >= '0' && *symbol <= '9') return *symbol;
- for (char *c = symbol; *c != '\0'; c++) {
- if (!((*c >= 'A' && *c <= 'Z') || (*c >= 'a' && *c <= 'z')
- || (*c >= '0' && *c <= '9')
- || *c == '_' || *c == '.' || *c == '$' || *c == ':')
- ) {
- return *c;
- }
- }
- return -1;
-}
-
-void print_symbols(struct symbol *symbols, int cnt) {
- printf("====== SYMBOLS =====\nlabel\taddr\n");
- for (int i = 0; i < cnt; i++) {
- printf("%s\t%d\n", symbols[i].label, symbols[i].addr);
- }
-}
-
-void print_binary_and_asm(uint16_t *binary, char **asm_lines, int cnt) {
- printf("\n====== RESULTS =====\naddr\tbinary \tinst\n");
- for (int i = 0; i < cnt; i++) {
- char binary_str[17];
- binary_str[16] = '\0';
- for (int b = 0; b < 16; b++) {
- binary_str[b] = '0' + (*(binary + i) >> (15 - b)) % 2;
- }
- printf("%d\t%s\t%s\n", i, binary_str, asm_lines[i]);
- }
-}
-
-void write_binary(FILE *file, uint16_t *binary, int cnt) {
- for (int i = 0; i < cnt; i++) {
- char binary_str[17];
- binary_str[16] = '\0';
- for (int b = 0; b < 16; b++) {
- binary_str[b] = '0' + (*(binary + i) >> (15 - b)) % 2;
- }
- fprintf(file, "%s\n", binary_str);
- }
-}
-
-uint16_t assemble_inst(char *asm_line) {
- // assemble one line of assembly, terminated with \0
- // labels and variables must be replaced with corresponding addresses beforehand
- uint16_t inst = 0;
- if (*asm_line == '@') {
- // A instruction
- char *addr_str = asm_line + 1;
- int addr = atoi(addr_str);
- if (addr < 0 || addr > MAX_ADDR) {
- fprintf(stderr, "Address out of range: %d\n", addr);
- exit(EXIT_CODE_ADDR_ERROR);
- }
- inst = (uint16_t) addr;
- } else {
- // C instruction
- inst = 0xe000; // set 3 MSBs to 1
- char *eq = asm_line;
- for (char *c = asm_line; *c != '\0'; c++) {
- // find first equal sign (eq == asm_line if not found)
- if (*c == '=') {
- eq = c;
- break;
- }
- }
-
- // slice out destination and copy to dest
- int dest_len = eq - asm_line;
- char *dest = malloc(dest_len + 1);
- strncpy(dest, asm_line, dest_len);
- dest[dest_len] = '\0';
- if (dest_len == 0) {} // ignore
- else if (strcmp(dest, "M") == 0) inst |= 0b001 << 3;
- else if (strcmp(dest, "D") == 0) inst |= 0b010 << 3;
- else if (strcmp(dest, "MD") == 0) inst |= 0b011 << 3;
- else if (strcmp(dest, "A") == 0) inst |= 0b100 << 3;
- else if (strcmp(dest, "AM") == 0) inst |= 0b101 << 3;
- else if (strcmp(dest, "AD") == 0) inst |= 0b110 << 3;
- else if (strcmp(dest, "AMD") == 0) inst |= 0b111 << 3;
- else {
- fprintf(stderr, "Invalid destination: %s\n", dest);
- exit(EXIT_CODE_SYNTAX_ERROR);
- }
- free(dest);
-
- char *semi = eq;
- for (; *semi != '\0'; semi++) {
- // find jump instruction after semicolon (;) (*semi == '\0' if not found)
- if (*semi == ';') break;
- }
- // ignore if there's no semicolon, or there's nothing after it
- if (*semi == '\0' || *(semi + 1) == '\0') {}
- else if (strcmp(semi + 1, "JGT") == 0) inst |= 0b001;
- else if (strcmp(semi + 1, "JEQ") == 0) inst |= 0b010;
- else if (strcmp(semi + 1, "JGE") == 0) inst |= 0b011;
- else if (strcmp(semi + 1, "JLT") == 0) inst |= 0b100;
- else if (strcmp(semi + 1, "JNE") == 0) inst |= 0b101;
- else if (strcmp(semi + 1, "JLE") == 0) inst |= 0b110;
- else if (strcmp(semi + 1, "JMP") == 0) inst |= 0b111;
- else {
- fprintf(stderr, "Invalid jump instruction: %s\n", semi + 1);
- exit(EXIT_CODE_SYNTAX_ERROR);
- }
-
- // slice out computation and copy to comp
- int comp_len = (*eq == '=') ? (semi - eq - 1) : (semi - eq);
- char *comp = malloc(comp_len + 1);
- strncpy(comp, (*eq == '=') ? (eq + 1) : eq, comp_len);
- comp[comp_len] = '\0';
- if (strcmp(comp, "0") == 0) inst |= 0b0101010 << 6;
- else if (strcmp(comp, "1") == 0) inst |= 0b0111111 << 6;
- else if (strcmp(comp, "-1") == 0) inst |= 0b0111010 << 6;
- else if (strcmp(comp, "D") == 0) inst |= 0b0001100 << 6;
- else if (strcmp(comp, "A") == 0) inst |= 0b0110000 << 6;
- else if (strcmp(comp, "M") == 0) inst |= 0b1110000 << 6;
- else if (strcmp(comp, "!D") == 0) inst |= 0b0001101 << 6;
- else if (strcmp(comp, "!A") == 0) inst |= 0b0110001 << 6;
- else if (strcmp(comp, "!M") == 0) inst |= 0b1110001 << 6;
- else if (strcmp(comp, "-D") == 0) inst |= 0b0001111 << 6;
- else if (strcmp(comp, "-A") == 0) inst |= 0b0110011 << 6;
- else if (strcmp(comp, "-M") == 0) inst |= 0b1110011 << 6;
- else if (strcmp(comp, "D+1") == 0) inst |= 0b0011111 << 6;
- else if (strcmp(comp, "A+1") == 0) inst |= 0b0110111 << 6;
- else if (strcmp(comp, "M+1") == 0) inst |= 0b1110111 << 6;
- else if (strcmp(comp, "D-1") == 0) inst |= 0b0001110 << 6;
- else if (strcmp(comp, "A-1") == 0) inst |= 0b0110010 << 6;
- else if (strcmp(comp, "M-1") == 0) inst |= 0b1110010 << 6;
- else if (strcmp(comp, "D+A") == 0
- || strcmp(comp, "A+D") == 0) inst |= 0b0000010 << 6;
- else if (strcmp(comp, "D+M") == 0
- || strcmp(comp, "M+D") == 0) inst |= 0b1000010 << 6;
- else if (strcmp(comp, "D-A") == 0) inst |= 0b0010011 << 6;
- else if (strcmp(comp, "D-M") == 0) inst |= 0b1010011 << 6;
- else if (strcmp(comp, "A-D") == 0) inst |= 0b0000111 << 6;
- else if (strcmp(comp, "M-D") == 0) inst |= 0b1000111 << 6;
- else if (strcmp(comp, "D&A") == 0
- || strcmp(comp, "A&D") == 0) inst |= 0b0000000 << 6;
- else if (strcmp(comp, "D&M") == 0
- || strcmp(comp, "M&D") == 0) inst |= 0b1000000 << 6;
- else if (strcmp(comp, "D|A") == 0
- || strcmp(comp, "A|D") == 0) inst |= 0b0010101 << 6;
- else if (strcmp(comp, "D|M") == 0
- || strcmp(comp, "M|D") == 0) inst |= 0b1010101 << 6;
- else {
- fprintf(stderr, "Invalid computation: %s\n", comp);
- exit(EXIT_CODE_SYNTAX_ERROR);
- }
- free(comp);
- }
- return inst;
-}
-
-size_t assembler(char *input_fn, bool verbose) {
- // open input file
- FILE *input_file = fopen(input_fn, "r");
- if (input_file == NULL) {
- fprintf(stderr, "Cannot open input file: %s\n", input_fn);
- exit(EXIT_CODE_FILE_ERROR);
- }
- // find size of input file
- fseek(input_file, 0, SEEK_END);
- size_t file_size = ftell(input_file);
- fseek(input_file, 0, SEEK_SET);
- // read input file
- char *file_content = malloc(file_size);
- fread(file_content, file_size, 1, input_file);
- fclose(input_file);
-
- // strip away comments, labels, blank lines and whitespace from file_content
- // 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 = 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
- struct symbol symbols[MAX_INST_LEN] = {
- {"SP", 0}, {"LCL", 1}, {"ARG", 2}, {"THIS", 3}, {"THAT", 4},
- {"R0", 0}, {"R1", 1}, {"R2", 2}, {"R3", 3},
- {"R4", 4}, {"R5", 5}, {"R6", 6}, {"R7", 7},
- {"R8", 8}, {"R9", 9}, {"R10", 10}, {"R11", 11},
- {"R12", 12}, {"R13", 13}, {"R14", 14}, {"R15", 15},
- {"SCREEN", 16384}, {"KBD", 24576},
- };
- const int predef_symbol_cnt = 23; // no. of predefined symbols
- int user_symbol_cnt = 0;
- for (size_t i = 0; i < file_size; i++) {
- switch (file_content[i]) {
- case '\n':
- // end of line; try to figure out what's in asm_line
- if (asm_char_cnt == 0) continue; // skip blank line or comment line
- *(asm_line + asm_char_cnt) = '\0';
- if (*asm_line == '(' && *(asm_line + asm_char_cnt - 1) == ')') {
- // this line may be a label; extract label from between the parentheses
- char *label = malloc(asm_char_cnt - 1);
- strncpy(label, asm_line + 1, asm_char_cnt - 2);
- free(asm_line);
- *(label + asm_char_cnt - 2) = '\0';
- char illegal_char = find_illegal_symbol_char(label);
- if (illegal_char != -1) {
- fprintf(stderr, "Illegal character: %c\n", illegal_char);
- exit(EXIT_CODE_ILLEGAL_CHAR);
- }
- // TODO: error on repeated label
- symbols[predef_symbol_cnt + user_symbol_cnt] = (struct symbol) {label, asm_line_cnt};
- user_symbol_cnt++;
- } else {
- // 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 + 1);
- break;
- case '/':
- if (i + 1 < file_size && file_content[i + 1] == '/') {
- // we encountered a comment
- // skip to last char of line
- while (i + 1 < file_size && file_content[i + 1] != '\n') i++;
- } else {
- fprintf(stderr, "Illegal character: /\n");
- exit(EXIT_CODE_ILLEGAL_CHAR);
- }
- break;
- case ' ':
- case '\t':
- case '\r':
- break; // ignore whitespace and CR
- default:
- *(asm_line + asm_char_cnt) = file_content[i];
- asm_char_cnt++;
- if (asm_char_cnt > MAX_ASM_LINE_LEN) {
- fprintf(stderr, "Max assembly line length (%d) exceeded\n", MAX_ASM_LINE_LEN);
- exit(EXIT_CODE_SIZE_EXCEEDED);
- }
- }
- }
- free(asm_line);
- free(file_content);
-
- // find and assign address to variables on the fly
- int addr = 16; // variable addresses start at 16
- for (int i = 0; i < asm_line_cnt; i++) {
- if (asm_lines[i] == NULL) break; // no more instructions
- if (*(asm_lines[i]) != '@') continue; // not an A-instruction
- char *addr_str = malloc(strlen(asm_lines[i]));
- strcpy(addr_str, asm_lines[i] + 1); // whatever comes after the @
- if (strlen(addr_str) == 0) {
- fprintf(stderr, "Address cannot be empty\n");
- exit(EXIT_CODE_SYNTAX_ERROR);
- }
- bool is_symbol = false;
- for (char *c = addr_str; *c != '\0'; c++) {
- // search for non-numeric chars in addr_str
- if (*c < '0' || *c > '9') {
- is_symbol = true;
- }
- }
- 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);
- exit(EXIT_CODE_ILLEGAL_CHAR);
- }
- // search for symbol in list
- bool found = false;
- for (int s = 0; s < predef_symbol_cnt + user_symbol_cnt; s++) {
- if (strcmp(addr_str, symbols[s].label) == 0) {
- // overwrite asm line with decimal constant
- sprintf(asm_lines[i], "@%d", symbols[s].addr);
- found = true;
- free(addr_str);
- break;
- }
- }
- if (!found) {
- // add symbol to list
- symbols[predef_symbol_cnt + user_symbol_cnt] = (struct symbol) {addr_str, addr};
- sprintf(asm_lines[i], "@%d", addr);
- user_symbol_cnt++;
- addr++;
- }
- }
-
- // start assembling
- uint16_t *binary = calloc(32768, 2);
- size_t inst_cnt = 0; // current no. of instructions in binary
- for (char **line = asm_lines; *line != NULL; line++) {
- *(binary + inst_cnt) = assemble_inst(*line);
- inst_cnt++;
- if (inst_cnt > MAX_INST_LEN) {
- fprintf(stderr, "Max number of instruction (%d) exceeded\n", MAX_INST_LEN);
- exit(EXIT_CODE_SIZE_EXCEEDED);
- }
- }
-
- if (verbose) {
- print_symbols(symbols + predef_symbol_cnt, user_symbol_cnt);
- print_binary_and_asm(binary, asm_lines, inst_cnt);
- printf("\n");
- }
-
- 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);
- }
-
- // write binary
- // output_fn = input_fn[:-4] + ".hack" if input_fn.endswith(".asm") else input_fn + ".hack"
- int input_fn_len = strlen(input_fn);
- char *output_fn = malloc(input_fn_len + 6);
- strcpy(output_fn, input_fn);
- if (input_fn_len >= 4 && strcmp(input_fn + input_fn_len - 4, ".asm") == 0) {
- sprintf(output_fn + input_fn_len - 4, ".hack");
- } else {
- sprintf(output_fn + input_fn_len, ".hack");
- }
-
- FILE *output_file = fopen(output_fn, "w");
- if (output_file == NULL) {
- fprintf(stderr, "Cannot open output file: %s\n", output_fn);
- exit(EXIT_CODE_FILE_ERROR);
- }
- write_binary(output_file, binary, inst_cnt);
- fclose(output_file);
- free(binary);
- printf("Binary written to %s\n", output_fn);
- free(output_fn);
-
- return inst_cnt;
-}
-
-int main(int argc, char *argv[]) {
- char *input_fn = NULL;
- bool verbose = false;
- for (int i = 1; i < argc; i++) {
- if (strcmp(argv[i], "-h") == 0) {
- printf("Usage: %s <input.asm> [-v]\n-v -- verbose mode\n", argv[0]);
- exit(0);
- } else if (strcmp(argv[i], "-v") == 0) {
- verbose = true;
- } else {
- input_fn = argv[i];
- }
- }
-
- assembler(input_fn, verbose);
- return 0;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-01 15:46:32 +0000