[Bug gcov-profile/85217] New: [GCOV] A no side effect statement between a break statement and a continue statement will lead to incorrect code coverage in gcov

[yangyibiao at nju dot edu.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85217

            Bug ID: 85217
           Summary: [GCOV] A no side effect statement between a break
                    statement and a continue statement will lead to
                    incorrect code coverage in gcov
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: gcov-profile
          Assignee: unassigned at gcc dot gnu.org
          Reporter: yangyibiao at nju dot edu.cn
                CC: marxin at gcc dot gnu.org
  Target Milestone: ---

$ cat small.c
int a=0;

void main() {
  for (;; a++) {
    int c[1];
    if (a) {
      break;
      a;
      continue;
    }
    continue;
  }
}


$ gcc -w --coverage small.c; ./a.out; gcov-8 small.c; cat small.c.gcov
File 'small.c'
Lines executed:100.00% of 7
Creating 'small.c.gcov'

        -:    0:Source:small.c
        -:    0:Graph:small.gcno
        -:    0:Data:small.gcda
        -:    0:Runs:1
        -:    0:Programs:1
        -:    1:int a=0;
        -:    2:
        2:    3:void main() {
        1:    4:  for (;; a++) {
        -:    5:    int c[1];
        2:    6:    if (a) {
        1:    7:      break;
        -:    8:      a;
        1:    9:      continue;
        -:   10:    }
        1:   11:    continue;
        -:   12:  }
        1:   13:}

Line #9 is wrongly marked as executed. While Line #8 or Line #11 is removed,
the result is correct.