https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121409
Bug ID: 121409
Summary: [GCOV] A simple if-statement inside nested structure
gets wrong coverage.
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: njuwy at smail dot nju.edu.cn
Target Milestone: ---
gcc version:
gcc version 16.0.0 20250804 (experimental) (GCC)
cmd:
gcc --coverage -std=c2x -lm -O0 test.c -o test
./test
gcov ./*.gcda -t > test.c.gcov
$ cat test.c
#include <stddef.h>
#include <ctype.h>
#include <stdlib.h>
#include <stdio.h>
int process_array(const int *data, size_t len, nullptr_t nptr)
{
int sum = 0;
size_t i = 0;
while (i < len) {
char c = (char)(data[i] & 0xFF);
if (nptr == nullptr && isdigit(c)) {
sum += data[i] % 10;
if (sum > 100) {
sum += 1;
} else {
sum += 2;
}
} else {
sum -= (int)len;
break;
}
i += (sum & 1) ? 1 : 2;
}
return sum;
}
int main(void)
{
int arr[] = { 52, 65, 50, 53, 90 };
nullptr_t nptr = nullptr;
printf("%d\n", process_array(arr, 5, nptr));
return EXIT_SUCCESS;
}
$ cat test.c.gcov
-: 1:#include <stddef.h>
-: 2:#include <ctype.h>
-: 3:#include <stdlib.h>
-: 4:#include <stdio.h>
1: 5:int process_array(const int *data, size_t len, nullptr_t nptr)
-: 6:{
1: 7: int sum = 0;
1: 8: size_t i = 0;
3: 9: while (i < len) {
3: 10: char c = (char)(data[i] & 0xFF);
3: 11: if (nptr == nullptr && isdigit(c)) {
2: 12: sum += data[i] % 10;
4: 13: if (sum > 100) {
#####: 14: sum += 1;
-: 15: } else {
2: 16: sum += 2;
-: 17: }
-: 18: } else {
1: 19: sum -= (int)len;
1: 20: break;
-: 21: }
2*: 22: i += (sum & 1) ? 1 : 2;
-: 23: }
1: 24: return sum;
-: 25:}
1: 26:int main(void)
-: 27:{
1: 28: int arr[] = { 52, 65, 50, 53, 90 };
1: 29: nullptr_t nptr = nullptr;
1: 30: printf("%d\n", process_array(arr, 5, nptr));
1: 31: return EXIT_SUCCESS;
-: 32:}
Cov of line 13 should be 2 instead of 4.
