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Reject malformed inputs in the term parser #320

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2 changes: 1 addition & 1 deletion input_files/bug-68.ms
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Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
x,y,z
257
0,
x*x+y*y+z*z,
x^2+y^2+z^2,
x+y+z,
x+y*z
2 changes: 1 addition & 1 deletion input_files/radical-shape-qq.ms
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Original file line number Diff line number Diff line change
Expand Up @@ -2,4 +2,4 @@ x, y, z
0
-2*z^3-3*z^2+x-5*z-7,
-z^3+z^2+y-z+1,
z^4-z^3-z^2-*z-1
z^4-z^3-z^2-z-1
113 changes: 103 additions & 10 deletions src/msolve/iofiles.c
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Original file line number Diff line number Diff line change
Expand Up @@ -18,29 +18,51 @@
* Christian Eder
* Mohab Safey El Din */

static inline void store_exponent(const char *term, data_gens_ff_t *gens, int32_t pos)
#include <errno.h>

static inline int store_exponent(const char *term, data_gens_ff_t *gens, int32_t pos)
{
len_t i, j, k;

len_t op = 0;
len_t index = 0;

int res = 0;
mpz_t tmp_z;
mpq_t tmp_q;
if (gens->field_char > 0) {
mpz_init(tmp_z);
} else {
mpq_init(tmp_q);
}

char *var = NULL;
char *ev = NULL;
char *end = NULL;
for (i = 0; i < strlen(term)+1; ++i) {
if (term[i] == '*' || i == strlen(term)) {
j = op;
while (j < i && term[j] != '^') {
++j;
}
if (term[j-1] == ',') {
--j;
}
while(term[op] == ' ' || term[op] == '+' || term[op] == '-') {
++op;
}
if (op >= j) {
fprintf(stderr, "Error when parsing term %s (missing operand for *)\n", term);
res = 1;
break;
}
var = realloc(var, sizeof(char)*(j-op+1));
memcpy(var, term+op, j-op);
var[j-op] = '\0';
if (term[j] == '^') {
int has_exponent = (j < i && term[j] == '^');
if (has_exponent) {
if (j + 1 >= i) {
fprintf(stderr, "Error when parsing term %s (missing exponent)\n", term);
res = 1;
break;
}
ev = realloc(ev, (sizeof(char)*(i-j)));
ev = memcpy(ev, term+(j+1), i-j-1);
ev[i-j-1] = '\0';
Expand All @@ -49,17 +71,76 @@ static inline void store_exponent(const char *term, data_gens_ff_t *gens, int32_
ev[0] = '1';
ev[1] ='\0';
}
int is_var = 0;
for (k = 0; k < gens->nvars; ++k) {
if (strcmp(gens->vnames[k], var) == 0) {
((gens->exps) + pos)[k] = strtol(ev, NULL, 10);
is_var = 1;
if (((gens->exps) + pos)[k] != 0) {
fprintf(stderr, "Error when parsing term %s (variable appears multiple times)\n", term);
res = 1;
break;
}
long val = strtol(ev, &end, 10);
if (ev == end) {
fprintf(stderr, "Error when parsing term %s (invalid exponent)\n", term);
res = 1;
break;
}
if (errno == ERANGE || val > INT_MAX) {
fprintf(stderr, "Error when parsing term %s (exponent out of range)\n", term);
res = 1;
break;
}
if (val <= 0) {
fprintf(stderr, "Error when parsing term %s (exponent must be positive)\n", term);
res = 1;
break;
}
((gens->exps) + pos)[k] = val;
break;
}
}
if (res == 1) {
break;
}
if (is_var == 0) {
if (has_exponent) {
fprintf(stderr, "Error when parsing term %s (coefficient cannot have an exponent)\n", term);
res = 1;
break;
}
if (index > 0) {
fprintf(stderr, "Error when parsing term %s (multiple coefficients are not allowed)\n", term);
res = 1;
break;
}
if (gens->field_char > 0) {
if (mpz_set_str(tmp_z, var, 10) != 0) {
fprintf(stderr, "Error when parsing term %s (invalid coefficient for finite field)\n", term);
res = 1;
break;
}
} else {
if (mpq_set_str(tmp_q, var, 10) != 0) {
fprintf(stderr, "Error when parsing term %s (invalid coefficient)\n", term);
res = 1;
break;
}
}
}
op = i+1;
index++;
}
}

free(var);
free(ev);
if (gens->field_char > 0) {
mpz_clear(tmp_z);
} else {
mpq_clear(tmp_q);
}
return res;
}


Expand Down Expand Up @@ -751,7 +832,10 @@ static int get_coefficient_ff_and_term_from_line(char *line, int32_t nterms,
iv_tmp += field_char; //MS change int -> long int
}
gens->cfs[pos] = (int32_t)iv_tmp;
store_exponent(term, gens, pos*gens->nvars);
if (store_exponent(term, gens, pos*gens->nvars)) {
free(term);
return 1;
}
for(int j = 1; j < nterms; j++){
get_term(line, &prev_pos, &term, &term_size);
if (term != NULL) {
Expand All @@ -769,7 +853,10 @@ static int get_coefficient_ff_and_term_from_line(char *line, int32_t nterms,
cf_tmp += field_char;
}
gens->cfs[pos+j] = (int32_t)cf_tmp;
store_exponent(term, gens, (pos+j)*gens->nvars);
if (store_exponent(term, gens, (pos+j)*gens->nvars)) {
free(term);
return 1;
}
}
// store_exponent(term, basis, ht);
}
Expand Down Expand Up @@ -857,11 +944,17 @@ static int get_coefficient_mpz_and_term_from_line(char *line, int32_t nterms,
if(term != NULL){

beginning_strterm_to_mpz(term, gens->mpz_cfs[pos], gens->mpz_cfs[pos+1]);
store_exponent(term, gens, pos/2*gens->nvars);
if (store_exponent(term, gens, pos/2*gens->nvars)) {
free(term);
return 1;
}
for(int j = 2; j < 2*nterms; j+=2){
get_term(line, &prev_pos, &term, &term_size);
inner_strterm_to_mpz(term, gens->mpz_cfs[pos+j], gens->mpz_cfs[pos+j+1]);
store_exponent(term, gens, ((pos+j)/2)*gens->nvars);
if (store_exponent(term, gens, ((pos+j)/2)*gens->nvars)) {
free(term);
return 1;
}
}
free(term);
return 0;
Expand Down
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