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authorDenys Vlasenko <vda.linux@googlemail.com>2018-12-03 14:02:35 +0100
committerDenys Vlasenko <vda.linux@googlemail.com>2018-12-05 15:43:35 +0100
commitcfdc1334c3e0cfbbe41f850e426c51c37a653dfb (patch)
tree36e563d437ede8e7022aec6cd23fbe140fb83d1d
parent01cabafd05410548bd7f539fb09dc3a8a9f48e08 (diff)
downloadbusybox-cfdc1334c3e0cfbbe41f850e426c51c37a653dfb.tar.gz
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>
-rw-r--r--miscutils/bc.c107
1 files changed, 49 insertions, 58 deletions
diff --git a/miscutils/bc.c b/miscutils/bc.c
index ee6cc47ce..c3d118417 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -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);
@@ -6456,17 +6468,15 @@ 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) {
- fflush(stdout);
- fputs(bc_program_ready_msg, stderr);
- fflush(stderr);
- s = BC_STATUS_SUCCESS;
- }
- else
- s = BC_STATUS_QUIT;
+ if (!G.ttyin)
+ quit();
+ fflush(stdout);
+ fputs(bc_program_ready_msg, stderr);
+ fflush(stderr);
+ s = BC_STATUS_SUCCESS;
}
return s;
@@ -6524,7 +6534,7 @@ static BcStatus bc_program_exec(void)
case BC_INST_HALT:
{
- s = BC_STATUS_QUIT;
+ quit();
break;
}
@@ -6767,9 +6777,8 @@ static BcStatus bc_program_exec(void)
case BC_INST_QUIT:
{
if (G.prog.stack.len <= 2)
- s = BC_STATUS_QUIT;
- else
- bc_vec_npop(&G.prog.stack, 2);
+ 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;
- }
+ 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;
}