bc: handle "limits" and "quit" immediately at parse time

No need to propagate a special exit code.

function                                             old     new   delta
bc_parse_stmt                                       2197    2301    +104
quit                                                   -      38     +38
bc_read_line                                         344     349      +5
bc_program_reset                                     174     172      -2
bc_num_s                                             252     246      -6
bc_num_a                                             454     445      -9
bc_parse_parse                                       471     461     -10
bc_num_ulong                                          95      85     -10
bc_program_exec                                     4500    4478     -22
bc_vm_run                                           2006    1978     -28
bc_vm_process                                        291     139    -152
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/8 up/down: 147/-239)          Total: -92 bytes
   text	   data	    bss	    dec	    hex	filename
 987936	    485	   7296	 995717	  f3185	busybox_old
 987844	    485	   7296	 995625	  f3129	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-12-03 14:02:35 +01:00
parent 01cabafd05
commit cfdc1334c3

View File

@ -231,8 +231,8 @@ typedef enum BcStatus {
BC_STATUS_POSIX_FOR3,
BC_STATUS_POSIX_BRACE,
#endif
BC_STATUS_QUIT,
BC_STATUS_LIMITS,
// BC_STATUS_QUIT,
// BC_STATUS_LIMITS,
// BC_STATUS_INVALID_OPTION,
} BcStatus;
@ -1121,6 +1121,13 @@ static const char bc_lib[] = {
};
#endif // ENABLE_BC
static void quit(void) NORETURN;
static void quit(void)
{
fflush_all();
exit(ferror(stdout) || ferror(stderr));
}
static void bc_vec_grow(BcVec *v, size_t n)
{
size_t cap = v->cap * 2;
@ -1279,9 +1286,9 @@ static BcStatus bc_read_line(BcVec *vec, const char *prompt)
fflush(stdout);
#if ENABLE_FEATURE_BC_SIGNALS
if (bb_got_signal) { /* ^C was pressed */
if (bb_got_signal) { // ^C was pressed
intr:
bb_got_signal = 0; /* resets G_interrupt to zero */
bb_got_signal = 0; // resets G_interrupt to zero
fputs(IS_BC
? "\ninterrupt (type \"quit\" to exit)\n"
: "\ninterrupt (type \"q\" to exit)\n"
@ -1293,7 +1300,6 @@ static BcStatus bc_read_line(BcVec *vec, const char *prompt)
fflush(stderr);
#if ENABLE_FEATURE_BC_SIGNALS
again:
errno = 0;
#endif
do {
@ -1302,16 +1308,13 @@ static BcStatus bc_read_line(BcVec *vec, const char *prompt)
i = fgetc(stdin);
#if ENABLE_FEATURE_BC_SIGNALS
if (bb_got_signal) /* ^C was pressed */
goto intr;
#endif
if (i == EOF) {
#if ENABLE_FEATURE_BC_SIGNALS
if (errno == EINTR) {
// Both conditions appear simultaneously, check both just in case
if (errno == EINTR || bb_got_signal) {
// ^C was pressed
clearerr(stdin);
goto again;
goto intr;
}
#endif
if (ferror(stdin))
@ -4630,9 +4633,18 @@ static BcStatus bc_parse_stmt(BcParse *p)
case BC_LEX_KEY_LIMITS:
{
// "limits" is a compile-time command,
// the output is produced at _parse time_.
s = bc_lex_next(&p->l);
if (s) return s;
s = BC_STATUS_LIMITS;
printf("BC_BASE_MAX = %u\n", BC_MAX_OBASE);
printf("BC_DIM_MAX = %u\n", BC_MAX_DIM);
printf("BC_SCALE_MAX = %u\n", BC_MAX_SCALE);
printf("BC_STRING_MAX = %u\n", BC_MAX_STRING);
printf("BC_NAME_MAX = %u\n", BC_MAX_NAME);
printf("BC_NUM_MAX = %u\n", BC_MAX_NUM);
printf("MAX Exponent = %lu\n", BC_MAX_EXP);
printf("Number of vars = %lu\n", BC_MAX_VARS);
break;
}
@ -4644,10 +4656,10 @@ static BcStatus bc_parse_stmt(BcParse *p)
case BC_LEX_KEY_QUIT:
{
// Quit is a compile-time command. We don't exit directly,
// so the vm can clean up. Limits do the same thing.
s = BC_STATUS_QUIT;
break;
// "quit" is a compile-time command. For example,
// "if (0 == 1) quit" terminates when parsing the statement,
// not when it is executed
quit();
}
case BC_LEX_KEY_RETURN:
@ -4685,7 +4697,7 @@ static BcStatus bc_parse_parse(BcParse *p)
else
s = bc_parse_stmt(p);
if ((s && s != BC_STATUS_QUIT && s != BC_STATUS_LIMITS) || G_interrupt)
if (s || G_interrupt)
s = bc_parse_reset(p, s);
return s;
@ -6283,8 +6295,8 @@ static BcStatus bc_program_nquit(void)
if (G.prog.stack.len < val)
return BC_STATUS_EXEC_STACK;
else if (G.prog.stack.len == val)
return BC_STATUS_QUIT;
if (G.prog.stack.len == val)
quit();
bc_vec_npop(&G.prog.stack, val);
@ -6456,18 +6468,16 @@ static BcStatus bc_program_reset(BcStatus s)
ip = bc_vec_top(&G.prog.stack);
ip->idx = f->code.len;
if (!s && G_interrupt && !G.tty) return BC_STATUS_QUIT;
if (!s && G_interrupt && !G.tty) quit();
if (!s || s == BC_STATUS_EXEC_SIGNAL) {
if (G.ttyin) {
if (!G.ttyin)
quit();
fflush(stdout);
fputs(bc_program_ready_msg, stderr);
fflush(stderr);
s = BC_STATUS_SUCCESS;
}
else
s = BC_STATUS_QUIT;
}
return s;
}
@ -6524,7 +6534,7 @@ static BcStatus bc_program_exec(void)
case BC_INST_HALT:
{
s = BC_STATUS_QUIT;
quit();
break;
}
@ -6767,8 +6777,7 @@ static BcStatus bc_program_exec(void)
case BC_INST_QUIT:
{
if (G.prog.stack.len <= 2)
s = BC_STATUS_QUIT;
else
quit();
bc_vec_npop(&G.prog.stack, 2);
break;
}
@ -6781,7 +6790,7 @@ static BcStatus bc_program_exec(void)
#endif // ENABLE_DC
}
if ((s && s != BC_STATUS_QUIT) || G_interrupt) s = bc_program_reset(s);
if (s || G_interrupt) s = bc_program_reset(s);
// If the stack has changed, pointers may be invalid.
ip = bc_vec_top(&G.prog.stack);
@ -6895,30 +6904,14 @@ static BcStatus bc_vm_process(const char *text)
s = G.prs.parse(&G.prs);
if (s == BC_STATUS_LIMITS) {
printf("BC_BASE_MAX = %u\n", BC_MAX_OBASE);
printf("BC_DIM_MAX = %u\n", BC_MAX_DIM);
printf("BC_SCALE_MAX = %u\n", BC_MAX_SCALE);
printf("BC_STRING_MAX = %u\n", BC_MAX_STRING);
printf("BC_NAME_MAX = %u\n", BC_MAX_NAME);
printf("BC_NUM_MAX = %u\n", BC_MAX_NUM);
printf("MAX Exponent = %lu\n", BC_MAX_EXP);
printf("Number of vars = %lu\n", BC_MAX_VARS);
s = BC_STATUS_SUCCESS;
}
else {
if (s == BC_STATUS_QUIT) return s;
s = bc_vm_error(s, G.prs.l.f, G.prs.l.line);
if (s) return s;
}
}
if (BC_PARSE_CAN_EXEC(&G.prs)) {
s = bc_program_exec();
if (!s && G.tty) fflush(stdout);
if (s && s != BC_STATUS_QUIT)
fflush(stdout);
if (s)
s = bc_vm_error(bc_program_reset(s), G.prs.l.f, 0);
}
@ -7021,7 +7014,7 @@ static BcStatus bc_vm_stdin(void)
// INPUT_EOF will always happen when stdin is
// closed. It's not a problem in that case.
if (s == BC_STATUS_INPUT_EOF || s == BC_STATUS_QUIT)
if (s == BC_STATUS_INPUT_EOF)
s = BC_STATUS_SUCCESS;
if (str)
@ -7058,13 +7051,11 @@ static BcStatus bc_vm_exec(void)
for (i = 0; !s && i < G.files.len; ++i)
s = bc_vm_file(*((char **) bc_vec_item(&G.files, i)));
if (s && s != BC_STATUS_QUIT) return s;
if (s) return s;
if (IS_BC || !G.files.len) s = bc_vm_stdin();
if (!s && !BC_PARSE_CAN_EXEC(&G.prs)) s = bc_vm_process("");
if (s == BC_STATUS_QUIT)
s = BC_STATUS_SUCCESS;
return s;
}