[Bug gcov-profile/100751] __gcov_dump and __gcov_reset usage

["marxin at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100751

--- Comment #23 from Martin Liška <marxin at gcc dot gnu.org> ---
> So, for either a one time call of __gcov_dump (though we may attempt to call
> __gcov_dump many times)  or at the exit of the program execution, the merge
> of profile happens due to which __gcov_reset doesn't get reflected at all.
> Am I right ?

Oh, I actually wrongly updated the documentation. When __gcov_reset is called,
run-time counters are reset to zero AND __gcov_dump can be called again (or
profile will be saved at exit).

Slightly modified test-case does now:

$ cat sample-prog.c
#include <stdio.h>
#include <ctype.h>
#include <unistd.h>

extern void __gcov_reset(void);
extern void __gcov_flush(void);
extern void __gcov_dump( void);

int main()
{
    unsigned char c;
    int count=0;
        c = 'g';

        do {
    printf ("c: '%c'\n", c);

                if(c == 'g'){
                        __gcov_dump();
                        printf("__gcov_dump() invoked!\n");
                        c = 'r';
                }
                else if(c == 'r'){
                        __gcov_reset();
                        printf("__gcov_reset() invoked!\n");
                        c = 'f';
                }
                if(count == 2)
                        c = 'g';
                else if (count > 10)
                        c = 'e';
                count++;
        }while(c != 'e');

        return 0;
}

$ gcc sample-prog.c --coverage -g && ./a.out && gcov -t sample-prog.c
c: 'g'
__gcov_dump() invoked!
c: 'r'
__gcov_reset() invoked!
c: 'f'
c: 'g'
__gcov_dump() invoked!
c: 'r'
__gcov_reset() invoked!
c: 'f'
c: 'f'
c: 'f'
c: 'f'
c: 'f'
c: 'f'
c: 'f'
        -:    0:Source:sample-prog.c
        -:    0:Graph:sample-prog.gcno
        -:    0:Data:sample-prog.gcda
        -:    0:Runs:1
        -:    1:#include <stdio.h>
        -:    2:#include <ctype.h>
        -:    3:#include <unistd.h>
        -:    4:
        -:    5:extern void __gcov_reset(void);
        -:    6:extern void __gcov_flush(void);
        -:    7:extern void __gcov_dump( void);
        -:    8:
        1:    9:int main()
        -:   10:{
        -:   11:    unsigned char c;
        1:   12:    int count=0;
        1:   13:        c = 'g';
        -:   14:
        -:   15:        do {
       10:   16:    printf ("c: '%c'\n", c);
        -:   17:   
       10:   18:                if(c == 'g'){
        2:   19:                        __gcov_dump();
    #####:   20:                        printf("__gcov_dump() invoked!\n");
    #####:   21:                        c = 'r';
        -:   22:                }
        8:   23:                else if(c == 'r'){
    #####:   24:                        __gcov_reset();
        2:   25:                        printf("__gcov_reset() invoked!\n");
        2:   26:                        c = 'f';
        -:   27:                }
       10:   28:                if(count == 2)
        1:   29:                        c = 'g';
        9:   30:                else if (count > 10)
        1:   31:                        c = 'e';
       10:   32:                count++;
       10:   33:        }while(c != 'e');
        -:   34:    
        1:   35:        return 0;
        -:   36:}

Which should be correct in my oppinion.