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.ki...@boundarydevices.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
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