-----Original Message----- From: Troy Kisky [mailto:troy.kisky@boundarydevices.com] Sent: Wednesday, November 28, 2012 9:32 AM To: sbabic@denx.de Cc: dirk.behme@googlemail.com; u-boot@lists.denx.de; Liu Hui-R64343; festevam@gmail.com; Troy Kisky Subject: [PATCH V4 11/11] parse_helper: add expression evaluation
Basic expressions with order precedence is now supported. ie. (----3 + ((1+2*3)/--2 + --5 *(8/4))) is 16.
Signed-off-by: Troy Kisky troy.kisky@boundarydevices.com
Acked-by: Jason Liu r64343@freescale.com
tools/parse_helper.c | 172 +++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 162 insertions(+), 10 deletions(-)
diff --git a/tools/parse_helper.c b/tools/parse_helper.c index 0a5c5f6..50be832 100644 --- a/tools/parse_helper.c +++ b/tools/parse_helper.c @@ -97,20 +97,172 @@ int ph_skip_comma(struct parse_helper *ph) } }
+static const char precedence[] = {
- /* ( + - * / & ^ | ) */
0, 2, 2, 1, 1, 3, 4, 5, 6+}; +static const char unary_operations[] = "(+-"; static const char +binary_operations[] = " +-*/&^|)";
+static uint32_t do_func(uint32_t val1, uint32_t val2, int op) {
- switch (op) {
- case 1:
return val1 + val2;- case 2:
return val1 - val2;- case 3:
return val1 * val2;- case 4:
return val1 / val2;- case 5:
return val1 & val2;- case 6:
return val1 ^ val2;- case 7:
return val1 | val2;- }
- fprintf(stderr, "Error: in func %s: val1=%d val2=%d op = %d\n",
__func__, val1, val2, op);- exit(EXIT_FAILURE);
+}
+static int find_op(char c, const char *p) {
- int i;
- for (i = 0; ; i++) {
if (c == p[i])return i;if (!p[i])break;- }
- return -1;
+}
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
int ph_get_value(struct parse_helper *ph, uint32_t *pval) { char *endptr;
- uint32_t value;
- int op_i = 0;
- int val_i = 0;
- unsigned char op[16];
- uint32_t val[16];
- int unary = 1;
- char *p;
- if (ph_skip_separators(ph))
return -1;- errno = 0;
- value = strtoul(ph->p, &endptr, 16);
- if (errno || (ph->p == endptr))
return -1;- *pval = value;
- ph->p = endptr;
- return 0;
- p = ph->p;
- for (;;) {
char c;int i, j;const char *ops = unary ? unary_operations :binary_operations;
if (unary) {ph->p = p;if (ph_skip_separators(ph))return -1;p = ph->p;c = *p;} else {for (;;) {c = *p;if ((c != ' ') && (c != '\t'))break;p++;}}i = find_op(c, ops);debug("%d,%c,%d:%s\n", i, c, unary, p);if ((i < 0) && unary) {if (val_i >= ARRAY_SIZE(val))return -1;errno = 0;val[val_i++] = strtoul(p, &endptr, 16);if (errno || (p == endptr)) {ph->p = p;return -1;}p = endptr;unary = 0;debug("val[%d]=%x,%d,%d\n", val_i - 1, val[val_i - 1],op_i, val_i);+do_unary:
while (op_i) {j = op[op_i - 1];if (!(j & 0x80))break;op_i--;val[val_i - 1] = do_func(0,val[val_i - 1], j & 0x7f);debug("un:%d,%x,%d,%d\n", val[val_i - 1], j,op_i, val_i);}continue;}if (i < 0) {c = 0;i = 8;} else {p++;}if (c == '(') {if (op_i >= ARRAY_SIZE(op))return -1;op[op_i++] = i;debug("op[%d]=%x,%d,%d\n", op_i - 1, op[op_i - 1],op_i, val_i);unary = 1;continue;}for (;;) {if (!op_i || unary)break;j = op[op_i - 1];if (j == 0) {if (c == ')') {op_i--;goto do_unary;}break;}if ((j & 0x80)) {op_i--;val[val_i - 1] = do_func(0,val[val_i - 1], j & 0x7f);debug("unary:%d,%x\n", val[val_i - 1], j);continue;}if (precedence[i] < precedence[j])break;if (val_i < 2)return -1;op_i--;val[val_i - 2] = do_func(val[val_i - 2],val[val_i - 1], j);val_i--;debug("binary:%d,%x,%d,%d\n", val[val_i - 1], j,op_i, val_i);}if (c == ')') {fprintf(stderr, "Error: unmatched parenthesis\n");return -1;}if (i == 8) {if ((op_i != 0) || (val_i != 1)) {fprintf(stderr, "Error: syntax %d %d\n",op_i, val_i);return -1;}ph->p = p;*pval = val[0];return 0;}if (op_i >= ARRAY_SIZE(op))return -1;op[op_i++] = i | (unary << 7);debug("op[%d]=%x,%d,%d\n", op_i - 1, op[op_i - 1], op_i, val_i);unary = 1;- }
}
/*
1.7.9.5