diff options
Diffstat (limited to '05/util.b')
| -rw-r--r-- | 05/util.b | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/05/util.b b/05/util.b new file mode 100644 index 0000000..13fed4d --- /dev/null +++ b/05/util.b @@ -0,0 +1,357 @@ + +function file_error + argument name + fputs(2, .str_file_error) + fputs(2, name) + fputc(2, 10) + exit(1) + +:str_file_error + string Error opening file: + byte 32 + byte 0 + +function malloc + argument size + local total_size + local memory + total_size = size + 8 + memory = syscall(9, 0, total_size, 3, 0x22, -1, 0) + if memory ] 0xffffffffffff0000 goto malloc_failed + *8memory = total_size + return memory + 8 + +:malloc_failed + fputs(2, .str_out_of_memory) + exit(1) + +:str_out_of_memory + string Out of memory. + byte 10 + byte 0 + +function free + argument memory + local psize + local size + psize = memory - 8 + size = *8psize + syscall(11, psize, size) + return + +; returns a pointer to a null-terminated string containing the number given +function itos + global 32 itos_string + argument x + local c + local p + p = &itos_string + p += 30 + :itos_loop + c = x % 10 + c += '0 + *1p = c + x /= 10 + if x == 0 goto itos_loop_end + p -= 1 + goto itos_loop + :itos_loop_end + return p + + +; returns the number at the start of the given string +function stoi + argument s + local p + local n + local c + n = 0 + p = s + :stoi_loop + c = *1p + if c < '0 goto stoi_loop_end + if c > '9 goto stoi_loop_end + n *= 10 + n += c - '0 + p += 1 + goto stoi_loop + :stoi_loop_end + return n + +function memchr + argument mem + argument c + local p + local a + p = mem + :memchr_loop + a = *1p + if a == c goto memchr_loop_end + p += 1 + goto memchr_loop + :memchr_loop_end + return p + +function strlen + argument s + local c + local p + p = s + :strlen_loop + c = *1p + if c == 0 goto strlen_loop_end + p += 1 + goto strlen_loop + :strlen_loop_end + return p - s + +function strcpy + argument dest + argument src + local p + local q + local c + p = dest + q = src + :strcpy_loop + c = *1q + *1p = c + if c == 0 goto strcpy_loop_end + p += 1 + q += 1 + goto strcpy_loop + :strcpy_loop_end + return p + +function str_startswith + argument s + argument prefix + local p + local q + local c1 + local c2 + p = s + q = prefix + :str_startswith_loop + c1 = *1p + c2 = *1q + if c2 == 0 goto return_1 + if c1 != c2 goto return_0 + p += 1 + q += 1 + goto str_startswith_loop + +function fputs + argument fd + argument s + local length + length = strlen(s) + syscall(1, fd, s, length) + return + +function puts + argument s + fputs(1, s) + return + +function fputn + argument fd + argument n + local s + s = itos(n) + fputs(fd, s) + return + +function fputc + argument fd + argument c + local p + p = &c + syscall(1, fd, p, 1) + return + +function putc + argument c + fputc(1, c) + return + +; returns 0 at end of file +function fgetc + argument fd + local c + local p + c = 0 + p = &c + syscall(0, fd, p, 1) + return c + +; read a line from fd as a null-terminated string +; returns 0 at end of file, 1 otherwise +function fgets + argument fd + argument buf + argument size + local p + local end + local c + p = buf + end = buf + size + + :fgets_loop + c = fgetc(fd) + if c == 0 goto fgets_eof + if c == 10 goto fgets_eol + *1p = c + p += 1 + if p == end goto fgets_eob + goto fgets_loop + + :fgets_eol ; end of line + *1p = 0 + return 1 + :fgets_eof ; end of file + *1p = 0 + return 0 + :fgets_eob ; end of buffer + p -= 1 + *1p = 0 + return 1 + +; open the given file for reading +function open_r + argument filename + local fd + fd = syscall(2, filename, 0) + if fd < 0 goto open_r_error + return fd + :open_r_error + file_error(filename) + return -1 + +; open the given file for writing with the given mode +function open_w + argument filename + argument mode + local fd + fd = syscall(2, filename, 0x241, mode) + if fd < 0 goto open_w_error + return fd + :open_w_error + file_error(filename) + return -1 + +function close + argument fd + syscall(3, fd) + return + +function isupper + argument c + if c < 'A goto return_0 + if c <= 'Z goto return_1 + goto return_0 + +function exit + argument status_code + syscall(0x3c, status_code) + +:return_0 + return 0 +:return_1 + return 1 + +function syscall + ; I've done some testing, and this should be okay even if + ; rbp-56 goes beyond the end of the stack. + ; mov rax, [rbp-16] + byte 0x48 + byte 0x8b + byte 0x85 + byte 0xf0 + byte 0xff + byte 0xff + byte 0xff + ; mov rdi, rax + byte 0x48 + byte 0x89 + byte 0xc7 + + ; mov rax, [rbp-24] + byte 0x48 + byte 0x8b + byte 0x85 + byte 0xe8 + byte 0xff + byte 0xff + byte 0xff + ; mov rsi, rax + byte 0x48 + byte 0x89 + byte 0xc6 + + ; mov rax, [rbp-32] + byte 0x48 + byte 0x8b + byte 0x85 + byte 0xe0 + byte 0xff + byte 0xff + byte 0xff + ; mov rdx, rax + byte 0x48 + byte 0x89 + byte 0xc2 + + ; mov rax, [rbp-40] + byte 0x48 + byte 0x8b + byte 0x85 + byte 0xd8 + byte 0xff + byte 0xff + byte 0xff + ; mov r10, rax + byte 0x49 + byte 0x89 + byte 0xc2 + + ; mov rax, [rbp-48] + byte 0x48 + byte 0x8b + byte 0x85 + byte 0xd0 + byte 0xff + byte 0xff + byte 0xff + ; mov r8, rax + byte 0x49 + byte 0x89 + byte 0xc0 + + ; mov rax, [rbp-56] + byte 0x48 + byte 0x8b + byte 0x85 + byte 0xc8 + byte 0xff + byte 0xff + byte 0xff + ; mov r9, rax + byte 0x49 + byte 0x89 + byte 0xc1 + + ; mov rax, [rbp-8] + byte 0x48 + byte 0x8b + byte 0x85 + byte 0xf8 + byte 0xff + byte 0xff + byte 0xff + + ; syscall + byte 0x0f + byte 0x05 + + return |