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bc: do not perform domr limit checks when they can't work (e.g. on 32-bit arches)

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Also, optimize printing of messages with fixed limit strings
by including limits as strings.

function                                             old     new   delta
bc_num_ulong                                         103      95      -8
bc_lex_number                                        296     281     -15
dc_lex_token                                         701     684     -17
bc_lex_name                                           90      73     -17
bc_num_shift                                          72      54     -18
bc_lex_token                                        1299    1280     -19
bc_parse_stmt                                       1868    1768    -100
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/7 up/down: 0/-194)           Total: -194 bytes
   text	   data	    bss	    dec	    hex	filename
 985814	    485	   7296	 993595	  f293b	busybox_old
 985526	    485	   7296	 993307	  f281b	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-12-07 15:50:14 +01:00
parent ffdcebdffe
commit 64074a1767
1 changed files with 76 additions and 33 deletions
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109
miscutils/bc.c
View File

@ -725,14 +725,39 @@ typedef unsigned long (*BcProgramBuiltIn)(BcNum *);
#define BC_MAX(a, b) ((a) > (b) ? (a) : (b))
#define BC_MIN(a, b) ((a) < (b) ? (a) : (b))
#define BC_MAX_OBASE ((unsigned) 999)
#define BC_MAX_DIM ((unsigned) INT_MAX)
#define BC_MAX_SCALE ((unsigned) UINT_MAX)
#define BC_MAX_STRING ((unsigned) UINT_MAX - 1)
#define BC_MAX_NAME BC_MAX_STRING
#define BC_MAX_NUM BC_MAX_STRING
#define BC_MAX_EXP ((unsigned long) LONG_MAX)
#define BC_MAX_VARS ((unsigned long) SIZE_MAX - 1)
#define BC_MAX_OBASE ((unsigned) 999)
#define BC_MAX_DIM ((unsigned) INT_MAX)
#define BC_MAX_SCALE ((unsigned) UINT_MAX)
#define BC_MAX_STRING ((unsigned) UINT_MAX - 1)
#define BC_MAX_NUM BC_MAX_STRING
// Unused apart from "limits" message. Just show a "biggish number" there.
//#define BC_MAX_NAME BC_MAX_STRING
//#define BC_MAX_EXP ((unsigned long) LONG_MAX)
//#define BC_MAX_VARS ((unsigned long) SIZE_MAX - 1)
#define BC_MAX_NAME_STR "999999999"
#define BC_MAX_EXP_STR "999999999"
#define BC_MAX_VARS_STR "999999999"
#define BC_MAX_OBASE_STR "999"
#if INT_MAX == 2147483647
# define BC_MAX_DIM_STR "2147483647"
#elif INT_MAX == 9223372036854775807
# define BC_MAX_DIM_STR "9223372036854775807"
#else
# error Strange INT_MAX
#endif
#if UINT_MAX == 4294967295
# define BC_MAX_SCALE_STR "4294967295"
# define BC_MAX_STRING_STR "4294967294"
#elif UINT_MAX == 18446744073709551615
# define BC_MAX_SCALE_STR "18446744073709551615"
# define BC_MAX_STRING_STR "18446744073709551614"
#else
# error Strange UINT_MAX
#endif
#define BC_MAX_NUM_STR BC_MAX_STRING_STR
struct globals {
IF_FEATURE_BC_SIGNALS(smallint ttyin;)
@ -1590,8 +1615,12 @@ static void bc_num_split(BcNum *restrict n, size_t idx, BcNum *restrict a,
static BcStatus bc_num_shift(BcNum *n, size_t places)
{
if (places == 0 || n->len == 0) return BC_STATUS_SUCCESS;
if (places + n->len > BC_MAX_NUM)
return bc_error("number too long: must be [1, BC_NUM_MAX]");
// This check makes sense only if size_t is (much) larger than BC_MAX_NUM.
if (SIZE_MAX > (BC_MAX_NUM | 0xff)) {
if (places + n->len > BC_MAX_NUM)
return bc_error("number too long: must be [1,"BC_MAX_NUM_STR"]");
}
if (n->rdx >= places)
n->rdx -= places;
@ -2891,8 +2920,11 @@ static BcStatus bc_lex_number(BcLex *l, char start)
}
len = i + !last_pt - bslashes * 2;
if (len > BC_MAX_NUM)
return bc_error("number too long: must be [1, BC_NUM_MAX]");
// This check makes sense only if size_t is (much) larger than BC_MAX_NUM.
if (SIZE_MAX > (BC_MAX_NUM | 0xff)) {
if (len > BC_MAX_NUM)
return bc_error("number too long: must be [1,"BC_MAX_NUM_STR"]");
}
bc_vec_pop_all(&l->t.v);
bc_vec_expand(&l->t.v, len + 1);
@ -2929,8 +2961,11 @@ static BcStatus bc_lex_name(BcLex *l)
while ((c >= 'a' && c <= 'z') || isdigit(c) || c == '_') c = buf[++i];
if (i > BC_MAX_STRING)
return bc_error("name too long: must be [1, BC_NAME_MAX]");
// This check makes sense only if size_t is (much) larger than BC_MAX_STRING.
if (SIZE_MAX > (BC_MAX_STRING | 0xff)) {
if (i > BC_MAX_STRING)
return bc_error("name too long: must be [1,"BC_MAX_STRING_STR"]");
}
bc_vec_string(&l->t.v, i, buf);
// Increment the index. We minus 1 because it has already been incremented.
@ -3047,8 +3082,11 @@ static BcStatus bc_lex_string(BcLex *l)
}
len = i - l->i;
if (len > BC_MAX_STRING)
return bc_error("string too long: must be [1, BC_STRING_MAX]");
// This check makes sense only if size_t is (much) larger than BC_MAX_STRING.
if (SIZE_MAX > (BC_MAX_STRING | 0xff)) {
if (len > BC_MAX_STRING)
return bc_error("string too long: must be [1,"BC_MAX_STRING_STR"]");
}
bc_vec_string(&l->t.v, len, l->buf + l->i);
l->i = i + 1;
@ -3426,8 +3464,11 @@ static BcStatus dc_lex_string(BcLex *l)
}
bc_vec_pushZeroByte(&l->t.v);
if (i - l->i > BC_MAX_STRING)
return bc_error("string too long: must be [1, BC_STRING_MAX]");
// This check makes sense only if size_t is (much) larger than BC_MAX_STRING.
if (SIZE_MAX > (BC_MAX_STRING | 0xff)) {
if (i - l->i > BC_MAX_STRING)
return bc_error("string too long: must be [1,"BC_MAX_STRING_STR"]");
}
l->i = i;
l->line += nls;
@ -4700,14 +4741,16 @@ static BcStatus bc_parse_stmt(BcParse *p)
// the output is produced at _parse time_.
s = bc_lex_next(&p->l);
if (s) return s;
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);
printf(
"BC_BASE_MAX = "BC_MAX_OBASE_STR "\n"
"BC_DIM_MAX = "BC_MAX_DIM_STR "\n"
"BC_SCALE_MAX = "BC_MAX_SCALE_STR "\n"
"BC_STRING_MAX = "BC_MAX_STRING_STR"\n"
"BC_NAME_MAX = "BC_MAX_NAME_STR "\n"
"BC_NUM_MAX = "BC_MAX_NUM_STR "\n"
"MAX Exponent = "BC_MAX_EXP_STR "\n"
"Number of vars = "BC_MAX_VARS_STR "\n"
);
break;
}
@ -5903,12 +5946,12 @@ static BcStatus bc_program_assign(char inst)
if (ib || sc || left->t == BC_RESULT_OBASE) {
static const char *const msg[] = {
"bad ibase; must be [2, 16]", //BC_RESULT_IBASE
"bad scale; must be [0, BC_SCALE_MAX]", //BC_RESULT_SCALE
NULL, //can't happen //BC_RESULT_LAST
NULL, //can't happen //BC_RESULT_CONSTANT
NULL, //can't happen //BC_RESULT_ONE
"bad obase; must be [2, BC_BASE_MAX]", //BC_RESULT_OBASE
"bad ibase; must be [2,16]", //BC_RESULT_IBASE
"bad scale; must be [0,"BC_MAX_SCALE_STR"]", //BC_RESULT_SCALE
NULL, //can't happen //BC_RESULT_LAST
NULL, //can't happen //BC_RESULT_CONSTANT
NULL, //can't happen //BC_RESULT_ONE
"bad obase; must be [2,"BC_MAX_OBASE_STR"]", //BC_RESULT_OBASE
};
size_t *ptr;
unsigned long val, max;
@ -6020,7 +6063,7 @@ static BcStatus bc_program_pushArray(char *code, size_t *bgn,
if (s) goto err;
if (temp > BC_MAX_DIM) {
s = bc_error("array too long; must be [1, BC_DIM_MAX]");
s = bc_error("array too long; must be [1,"BC_MAX_DIM_STR"]");
goto err;
}