busybox/miscutils/dc.c

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/* vi: set sw=4 ts=4: */
/*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
/* config/applet/usage bits are in bc.c */
//#include "libbb.h"
//#include "common_bufsiz.h"
#include <math.h>
#if 0
typedef unsigned data_t;
#define DATA_FMT ""
#elif 0
typedef unsigned long data_t;
#define DATA_FMT "l"
#else
typedef unsigned long long data_t;
#define DATA_FMT "ll"
#endif
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struct globals {
unsigned pointer;
unsigned base;
double stack[1];
} FIX_ALIASING;
enum { STACK_SIZE = (COMMON_BUFSIZE - offsetof(struct globals, stack)) / sizeof(double) };
#define G (*(struct globals*)bb_common_bufsiz1)
#define pointer (G.pointer )
#define base (G.base )
#define stack (G.stack )
#define INIT_G() do { \
setup_common_bufsiz(); \
base = 10; \
} while (0)
static unsigned check_under(void)
{
unsigned p = pointer;
if (p == 0)
libbb: reduce the overhead of single parameter bb_error_msg() calls Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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bb_simple_error_msg_and_die("stack underflow");
return p - 1;
}
static void push(double a)
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{
if (pointer >= STACK_SIZE)
libbb: reduce the overhead of single parameter bb_error_msg() calls Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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bb_simple_error_msg_and_die("stack overflow");
stack[pointer++] = a;
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}
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static double pop(void)
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{
unsigned p = check_under();
pointer = p;
return stack[p];
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}
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static void add(void)
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{
push(pop() + pop());
}
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static void sub(void)
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{
double subtrahend = pop();
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push(pop() - subtrahend);
}
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static void mul(void)
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{
push(pop() * pop());
}
#if ENABLE_FEATURE_DC_LIBM
static void power(void)
{
double topower = pop();
push(pow(pop(), topower));
}
#endif
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static void divide(void)
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{
double divisor = pop();
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push(pop() / divisor);
}
static void mod(void)
{
data_t d = pop();
/* compat with dc (GNU bc 1.07.1) 1.4.1:
* $ dc -e '4 0 % p'
* dc: remainder by zero
* 0
*/
if (d == 0) {
bb_simple_error_msg("remainder by zero");
pop();
push(0);
return;
}
/* ^^^^ without this, we simply get SIGFPE and die */
push((data_t) pop() % d);
}
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static void and(void)
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{
push((data_t) pop() & (data_t) pop());
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}
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static void or(void)
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{
push((data_t) pop() | (data_t) pop());
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}
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static void eor(void)
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{
push((data_t) pop() ^ (data_t) pop());
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}
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static void not(void)
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{
push(~(data_t) pop());
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}
static void set_output_base(void)
{
static const char bases[] ALIGN1 = { 2, 8, 10, 16, 0 };
unsigned b = (unsigned)pop();
base = *strchrnul(bases, b);
if (base == 0) {
bb_error_msg("error, base %u is not supported", b);
base = 10;
}
}
static void print_base(double print)
{
data_t x, i;
x = (data_t) print;
if (base == 10) {
if (x == print) /* exactly representable as unsigned integer */
printf("%"DATA_FMT"u\n", x);
else
printf("%g\n", print);
return;
}
switch (base) {
case 16:
printf("%"DATA_FMT"x\n", x);
break;
case 8:
printf("%"DATA_FMT"o\n", x);
break;
default: /* base 2 */
i = MAXINT(data_t) - (MAXINT(data_t) >> 1);
/* i is 100000...00000 */
do {
if (x & i)
break;
i >>= 1;
} while (i > 1);
do {
bb_putchar('1' - !(x & i));
i >>= 1;
} while (i);
bb_putchar('\n');
}
}
static void print_stack_no_pop(void)
{
unsigned i = pointer;
while (i)
print_base(stack[--i]);
}
static void print_no_pop(void)
{
print_base(stack[check_under()]);
}
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struct op {
const char name[4];
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void (*function) (void);
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};
static const struct op operators[] ALIGN_PTR = {
#if ENABLE_FEATURE_DC_LIBM
{"^", power},
// {"exp", power},
// {"pow", power},
#endif
{"%", mod},
// {"mod", mod},
// logic ops are not standard, remove?
{"and", and},
{"or", or},
{"not", not},
{"xor", eor},
{"+", add},
// {"add", add},
{"-", sub},
// {"sub", sub},
{"*", mul},
// {"mul", mul},
{"/", divide},
// {"div", divide},
{"p", print_no_pop},
{"f", print_stack_no_pop},
{"o", set_output_base},
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};
/* Feed the stack machine */
static void stack_machine(const char *argument)
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{
char *end;
double number;
const struct op *o;
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next:
number = strtod(argument, &end);
if (end != argument) {
argument = end;
push(number);
goto next;
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}
/* We might have matched a digit, eventually advance the argument */
argument = skip_whitespace(argument);
if (*argument == '\0')
return;
o = operators;
do {
libbb: introduce and use is_prefixed_with() function old new delta is_prefixed_with - 18 +18 complete_username 78 77 -1 man_main 737 735 -2 fsck_device 429 427 -2 unpack_ar_archive 80 76 -4 strip_unsafe_prefix 105 101 -4 singlemount 1054 1050 -4 rtc_adjtime_is_utc 90 86 -4 resolve_mount_spec 88 84 -4 parse_one_line 1029 1025 -4 parse_conf 1460 1456 -4 may_wakeup 83 79 -4 loadkmap_main 219 215 -4 get_irqs_from_stat 103 99 -4 get_header_cpio 913 909 -4 findfs_main 79 75 -4 fbsplash_main 1230 1226 -4 load_crontab 776 771 -5 expand_vars_to_list 1151 1146 -5 date_main 881 876 -5 skip_dev_pfx 30 24 -6 make_device 2199 2193 -6 complete_cmd_dir_file 773 767 -6 run_applet_and_exit 715 708 -7 uudecode_main 321 313 -8 pwdx_main 197 189 -8 execute 568 560 -8 i2cdetect_main 1186 1176 -10 procps_scan 1242 1230 -12 procps_read_smaps 1017 1005 -12 process_module 746 734 -12 patch_main 1903 1891 -12 nfsmount 3572 3560 -12 stack_machine 126 112 -14 process_timer_stats 449 435 -14 match_fstype 111 97 -14 do_ipaddr 1344 1330 -14 open_list_and_close 359 343 -16 get_header_tar 1795 1779 -16 prepend_new_eth_table 340 323 -17 fsck_main 1811 1794 -17 find_iface_state 56 38 -18 dnsd_main 1321 1303 -18 base_device 179 158 -21 find_keyword 104 82 -22 handle_incoming_and_exit 2785 2762 -23 parse_and_put_prompt 774 746 -28 modinfo 347 317 -30 find_action 204 171 -33 update_passwd 1470 1436 -34 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/49 up/down: 18/-540) Total: -522 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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char *after_name = is_prefixed_with(argument, o->name);
if (after_name) {
argument = after_name;
o->function();
goto next;
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}
o++;
} while (o != operators + ARRAY_SIZE(operators));
bb_error_msg_and_die("syntax error at '%s'", argument);
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}
static void process_file(FILE *fp)
{
char *line;
while ((line = xmalloc_fgetline(fp)) != NULL) {
stack_machine(line);
free(line);
}
}
int dc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int dc_main(int argc UNUSED_PARAM, char **argv)
{
bool script = 0;
INIT_G();
/* Run -e'SCRIPT' and -fFILE in order of appearance, then handle FILEs */
for (;;) {
int n = getopt(argc, argv, "e:f:");
if (n <= 0)
break;
switch (n) {
case 'e':
script = 1;
stack_machine(optarg);
break;
case 'f':
script = 1;
process_file(xfopen_for_read(optarg));
break;
default:
bb_show_usage();
}
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}
argv += optind;
if (*argv) {
do
process_file(xfopen_for_read(*argv++));
while (*argv);
} else if (!script) {
/* Take stuff from stdin if no args are given */
process_file(stdin);
}
return EXIT_SUCCESS;
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}