From e4ba4c43716b6f550de3bf922e6f25e2dd9e983e Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Mon, 17 Dec 2018 09:51:43 +0100 Subject: [PATCH] bc: parse file arguments piecemeal (do not read entire file) function old new delta bc_read_line 336 406 +70 zbc_vm_execute_FILE - 67 +67 zbc_lex_next 2309 2318 +9 zbc_program_exec 4002 4008 +6 bc_program_index 66 64 -2 bc_vm_run 139 124 -15 zbc_vm_file 208 32 -176 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 3/3 up/down: 152/-193) Total: -41 bytes text data bss dec hex filename 981736 485 7296 989517 f194d busybox_old 981667 485 7296 989448 f1908 busybox_unstripped Signed-off-by: Denys Vlasenko --- miscutils/bc.c | 183 +++++++++++++++++++++---------------------------- 1 file changed, 78 insertions(+), 105 deletions(-) diff --git a/miscutils/bc.c b/miscutils/bc.c index c92f6f813..2570e8313 100644 --- a/miscutils/bc.c +++ b/miscutils/bc.c @@ -694,7 +694,6 @@ struct globals { IF_FEATURE_BC_SIGNALS(smallint ttyin;) IF_FEATURE_CLEAN_UP(smallint exiting;) smallint in_read; - smallint use_stdin; BcParse prs; BcProgram prog; @@ -704,7 +703,8 @@ struct globals { unsigned err_line; BcVec files; - BcVec stdin_buffer; + BcVec input_buffer; + FILE *input_fp; char *env_args; @@ -1317,8 +1317,8 @@ static int bad_input_byte(char c) return 0; } -// Note: it _appends_ data from the stdin to vec. -static void bc_read_line(BcVec *vec) +// Note: it _appends_ data from fp to vec. +static void bc_read_line(BcVec *vec, FILE *fp) { again: fflush_and_check(); @@ -1326,6 +1326,17 @@ static void bc_read_line(BcVec *vec) #if ENABLE_FEATURE_BC_SIGNALS if (G_interrupt) { // ^C was pressed intr: + if (fp != stdin) { + // ^C while running a script (bc SCRIPT): die. + // We do not return to interactive prompt: + // user might be running us from a shell, + // and SCRIPT might be intended to terminate + // (e.g. contain a "halt" stmt). + // ^C dropping user into a bc prompt instead of + // the shell would be unexpected. + xfunc_die(); + } + // ^C while interactive input G_interrupt = 0; // GNU bc says "interrupted execution." // GNU dc says "Interrupt!" @@ -1333,14 +1344,14 @@ static void bc_read_line(BcVec *vec) } # if ENABLE_FEATURE_EDITING - if (G_ttyin) { + if (G_ttyin && fp == stdin) { int n, i; # define line_buf bb_common_bufsiz1 n = read_line_input(G.line_input_state, "", line_buf, COMMON_BUFSIZE); if (n <= 0) { // read errors or EOF, or ^D, or ^C if (n == 0) // ^C goto intr; - bc_vec_pushZeroByte(vec); + bc_vec_pushZeroByte(vec); // ^D or EOF (or error) return; } i = 0; @@ -1359,60 +1370,38 @@ static void bc_read_line(BcVec *vec) bool bad_chars = 0; size_t len = vec->len; - IF_FEATURE_BC_SIGNALS(errno = 0;) do { - c = fgetc(stdin); -#if ENABLE_FEATURE_BC_SIGNALS && !ENABLE_FEATURE_EDITING - // Both conditions appear simultaneously, check both just in case - if (errno == EINTR || G_interrupt) { - // ^C was pressed - clearerr(stdin); +#if ENABLE_FEATURE_BC_SIGNALS + if (G_interrupt) { + // ^C was pressed: ignore entire line, get another one + vec->len = len; goto intr; } #endif + c = fgetc(fp); if (c == EOF) { - if (ferror(stdin)) - quit(); // this emits error message - // Note: EOF does not append '\n', therefore: - // printf 'print 123\n' | bc - works - // printf 'print 123' | bc - fails (syntax error) + if (ferror(fp)) + bb_perror_msg_and_die("input error"); + // Note: EOF does not append '\n' break; } bad_chars |= bad_input_byte(c); bc_vec_pushByte(vec, (char)c); } while (c != '\n'); + if (bad_chars) { - // Bad chars on this line, ignore entire line - vec->len = len; - goto again; + // Bad chars on this line + if (!G.prog.file) { // stdin + // ignore entire line, get another one + vec->len = len; + goto again; + } + bb_perror_msg_and_die("file '%s' is not text", G.prog.file); } bc_vec_pushZeroByte(vec); } } -static char* bc_read_file(const char *path) -{ - char *buf; - size_t size = ((size_t) -1); - size_t i; - - // Never returns NULL (dies on errors) - buf = xmalloc_xopen_read_close(path, &size); - - for (i = 0; i < size; ++i) { - char c = buf[i]; - if ((c < ' ' && c != '\t' && c != '\r' && c != '\n') // also allow '\v' '\f'? - || c > 0x7e - ) { - free(buf); - buf = NULL; - break; - } - } - - return buf; -} - static void bc_num_setToZero(BcNum *n, size_t scale) { n->len = 0; @@ -2912,7 +2901,7 @@ static bool bc_lex_more_input(BcLex *l) size_t str; bool comment; - bc_vec_pop_all(&G.stdin_buffer); + bc_vec_pop_all(&G.input_buffer); // This loop is complex because the vm tries not to send any lines that end // with a backslash to the parser. The reason for that is because the parser @@ -2921,18 +2910,18 @@ static bool bc_lex_more_input(BcLex *l) comment = false; str = 0; for (;;) { - size_t prevlen = G.stdin_buffer.len; + size_t prevlen = G.input_buffer.len; char *string; - bc_read_line(&G.stdin_buffer); + bc_read_line(&G.input_buffer, G.input_fp); // No more input means EOF - if (G.stdin_buffer.len <= prevlen + 1) // (we expect +1 for NUL byte) + if (G.input_buffer.len <= prevlen + 1) // (we expect +1 for NUL byte) break; - string = G.stdin_buffer.v + prevlen; + string = G.input_buffer.v + prevlen; while (*string) { char c = *string; - if (string == G.stdin_buffer.v || string[-1] != '\\') { + if (string == G.input_buffer.v || string[-1] != '\\') { if (IS_BC) str ^= (c == '"'); else { @@ -2954,7 +2943,7 @@ static bool bc_lex_more_input(BcLex *l) } } if (str != 0 || comment) { - G.stdin_buffer.len--; // backstep over the trailing NUL byte + G.input_buffer.len--; // backstep over the trailing NUL byte continue; } @@ -2963,21 +2952,20 @@ static bool bc_lex_more_input(BcLex *l) // if it is not, then it's EOF, and looping back // to bc_read_line() will detect it: string -= 2; - if (string >= G.stdin_buffer.v && *string == '\\') { - G.stdin_buffer.len--; + if (string >= G.input_buffer.v && *string == '\\') { + G.input_buffer.len--; continue; } break; } - l->buf = G.stdin_buffer.v; + l->buf = G.input_buffer.v; l->i = 0; -//bb_error_msg("G.stdin_buffer.len:%d '%s'", G.stdin_buffer.len, G.stdin_buffer.v); - l->len = G.stdin_buffer.len - 1; // do not include NUL +// bb_error_msg("G.input_buffer.len:%d '%s'", G.input_buffer.len, G.input_buffer.v); + l->len = G.input_buffer.len - 1; // do not include NUL - G.use_stdin = (l->len != 0); - return G.use_stdin; + return l->len != 0; } static BC_STATUS zbc_lex_next(BcLex *l) @@ -2989,22 +2977,23 @@ static BC_STATUS zbc_lex_next(BcLex *l) l->line += l->newline; G.err_line = l->line; - - l->t.t = BC_LEX_EOF; -//this NL handling is bogus - l->newline = (l->i == l->len); - if (l->newline) { - if (!G.use_stdin || !bc_lex_more_input(l)) - RETURN_STATUS(BC_STATUS_SUCCESS); - // here it's guaranteed that l->i is below l->len - l->newline = false; - } + l->newline = false; // Loop until failure or we don't have whitespace. This // is so the parser doesn't get inundated with whitespace. // Comments are also BC_LEX_WHITESPACE tokens and eaten here. s = BC_STATUS_SUCCESS; do { + l->t.t = BC_LEX_EOF; + if (l->i == l->len) { + if (!G.input_fp) + RETURN_STATUS(BC_STATUS_SUCCESS); + if (!bc_lex_more_input(l)) { + G.input_fp = NULL; + RETURN_STATUS(BC_STATUS_SUCCESS); + } + // here it's guaranteed that l->i is below l->len + } dbg_lex("next string to parse:'%.*s'", (int)(strchrnul(l->buf + l->i, '\n') - (l->buf + l->i)), l->buf + l->i); @@ -5351,7 +5340,7 @@ static BC_STATUS zbc_program_read(void) G.in_read = 1; bc_char_vec_init(&buf); - bc_read_line(&buf); + bc_read_line(&buf, stdin); bc_parse_create(&parse, BC_PROG_READ); bc_lex_file(&parse.l); @@ -6931,60 +6920,44 @@ static BC_STATUS zbc_vm_process(const char *text) # define zbc_vm_process(...) (zbc_vm_process(__VA_ARGS__), BC_STATUS_SUCCESS) #endif -static BC_STATUS zbc_vm_file(const char *file) +static BC_STATUS zbc_vm_execute_FILE(FILE *fp, const char *filename) { // So far bc/dc have no way to include a file from another file, // therefore we know G.prog.file == NULL on entry //const char *sv_file; - char *data; BcStatus s; - BcFunc *main_func; - BcInstPtr *ip; - - data = bc_read_file(file); - if (!data) RETURN_STATUS(bc_error_fmt("file '%s' is not text", file)); - //sv_file = G.prog.file; - G.prog.file = file; + G.prog.file = filename; + G.input_fp = fp; bc_lex_file(&G.prs.l); - s = zbc_vm_process(data); - if (s) goto err; - - main_func = bc_program_func(BC_PROG_MAIN); - ip = bc_vec_item(&G.prog.stack, 0); - - if (main_func->code.len < ip->idx) - s = bc_error_fmt("file '%s' is not executable", file); -err: - //G.prog.file = sv_file; + do { + s = zbc_vm_process(""); + // We do not stop looping on errors here if reading stdin. + // Example: start interactive bc and enter "return". + // It should say "'return' not in a function" + // but should not exit. + } while (G.input_fp == stdin); G.prog.file = NULL; - free(data); RETURN_STATUS(s); } #if ERRORS_ARE_FATAL -# define zbc_vm_file(...) (zbc_vm_file(__VA_ARGS__), BC_STATUS_SUCCESS) +# define zbc_vm_execute_FILE(...) (zbc_vm_execute_FILE(__VA_ARGS__), BC_STATUS_SUCCESS) #endif -static BC_STATUS zbc_vm_stdin(void) +static BC_STATUS zbc_vm_file(const char *file) { BcStatus s; + FILE *fp; - //G.prog.file = NULL; - already is - bc_lex_file(&G.prs.l); + fp = xfopen_for_read(file); + s = zbc_vm_execute_FILE(fp, file); + fclose(fp); - G.use_stdin = 1; - do { - s = zbc_vm_process(""); - // We do not stop looping on errors here. - // Example: start interactive bc and enter "return". - // It should say "'return' not in a function" - // but should not exit. - } while (G.use_stdin); RETURN_STATUS(s); } #if ERRORS_ARE_FATAL -# define zbc_vm_stdin(...) (zbc_vm_stdin(__VA_ARGS__), BC_STATUS_SUCCESS) +# define zbc_vm_file(...) (zbc_vm_file(__VA_ARGS__), BC_STATUS_SUCCESS) #endif #if ENABLE_BC @@ -7257,7 +7230,7 @@ static BC_STATUS zbc_vm_exec(void) } if (IS_BC || (option_mask32 & BC_FLAG_I)) - s = zbc_vm_stdin(); + s = zbc_vm_execute_FILE(stdin, /*filename:*/ NULL); RETURN_STATUS(s); } @@ -7287,7 +7260,7 @@ static void bc_program_free(void) bc_num_free(&G.prog.last); bc_num_free(&G.prog.zero); bc_num_free(&G.prog.one); - bc_vec_free(&G.stdin_buffer); + bc_vec_free(&G.input_buffer); } static void bc_vm_free(void) @@ -7352,7 +7325,7 @@ static void bc_program_init(void) bc_vec_init(&G.prog.stack, sizeof(BcInstPtr), NULL); bc_vec_push(&G.prog.stack, &ip); - bc_char_vec_init(&G.stdin_buffer); + bc_char_vec_init(&G.input_buffer); } static int bc_vm_init(const char *env_len) -- 2.25.1