[Bug gcov-profile/85351] New: [GCOV] Wrong coverage with an executed exit() in if statement within a called function

[yangyibiao at nju dot edu.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85351

            Bug ID: 85351
           Summary: [GCOV] Wrong coverage with an executed exit() in if
                    statement within a called function
           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: ---

/********************** small.c *********************/
$ cat small.c
#include <stdlib.h>

void foo1(int x)
{
  if (x < 1)
    exit(0);
}

int main()
{
  foo1(0);
  return 0;
}

$ gcc --coverage small.c; ./a.out; gcov-8 small.c; cat small.c.gcov
File 'small.c'
Lines executed:71.43% 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:#include <stdlib.h>
        -:    2:
        1:    3:void foo1(int x)
        -:    4:{
        1:    5:  if (x < 1)
        1:    6:    exit(0);
    #####:    7:}
        -:    8:
        1:    9:int main()
        -:   10:{
        1:   11:  foo1(0);
    #####:   12:  return 0;
        -:   13:}

*************************
Line #7 is wrongly marked as "#####"
*************************

/********************** small2.c *********************/
$ cat small2.c
#include <stdlib.h>

void foo1(int x)
{
  // if (x < 1)
    exit(0);
}

int main()
{
  foo1(0);
  return 0;
}

$ gcc --coverage small2.c; ./a.out; gcov-8 small2.c; cat small2.c.gcov
File 'small2.c'
Lines executed:80.00% of 5
Creating 'small2.c.gcov'

        -:    0:Source:small2.c
        -:    0:Graph:small2.gcno
        -:    0:Data:small2.gcda
        -:    0:Runs:1
        -:    0:Programs:1
        -:    1:#include <stdlib.h>
        -:    2:
        1:    3:void foo1(int x)
        -:    4:{
        -:    5:  // if (x < 1)
        1:    6:    exit(0);
        -:    7:}
        -:    8:
        1:    9:int main()
        -:   10:{
        1:   11:  foo1(0);
    #####:   12:  return 0;
        -:   13:}



***************************
While comparing the coverage of small.c and small2.c, we can find that the
marks of Line #7 in these two files is inconsistant. This confirms that the
coverage of small.c is incorrect.