Hi.
I sent this email to David some time ago, but it should be probably answered
on gcc mailing list.
I have idea one to improve gcov tool and I'm interested in more precise
locations for gimple
statements. For gcov purpose, we dump location in ipa-profile pass, which is an
early IPA
pass and this data is used by gcov tool to map statements (blocks) to lines of
code.
I did a small experiment on the place we emit the location data:
inform (gimple_location (stmt), "output_location");
and it shows for:
$ cat m2.c
unsigned int
UuT (void)
{ unsigned int true_var = 1; unsigned int false_var = 0; unsigned int ret = 0;
if (true_var) /* count(1) */ { if (false_var) /* count(1) */ ret = 111; /*
count(#####) */ } else ret = 999; /* count(#####) */ return ret; }
int
main (int argc, char **argv)
{
UuT ();
return 0;
}
$ gcc --coverage m2.c
m2.c: In function ‘main’:
m2.c:8:3: note: output_location
UuT ();
^~~~~~
# .MEM_2 = VDEF <.MEM_1(D)>
UuT ();
m2.c:9:10: note: output_location
return 0;
^
_3 = 0;
m2.c: In function ‘UuT’:
m2.c:3:16: note: output_location
{ unsigned int true_var = 1; unsigned int false_var = 0; unsigned int ret = 0;
if (true_var) /* count(1) */ { if (false_var) /* count(1) */ ret = 111; /*
count(#####) */ } else ret = 999; /* count(#####) */ return ret; }
^~~~~~~~
true_var_3 = 1;
m2.c:3:43: note: output_location
{ unsigned int true_var = 1; unsigned int false_var = 0; unsigned int ret = 0;
if (true_var) /* count(1) */ { if (false_var) /* count(1) */ ret = 111; /*
count(#####) */ } else ret = 999; /* count(#####) */ return ret; }
^~~~~~~~~
false_var_4 = 0;
m2.c:3:71: note: output_location
{ unsigned int true_var = 1; unsigned int false_var = 0; unsigned int ret = 0;
if (true_var) /* count(1) */ { if (false_var) /* count(1) */ ret = 111; /*
count(#####) */ } else ret = 999; /* count(#####) */ return ret; }
^~~
ret_5 = 0;
m2.c:3:83: note: output_location
{ unsigned int true_var = 1; unsigned int false_var = 0; unsigned int ret = 0;
if (true_var) /* count(1) */ { if (false_var) /* count(1) */ ret = 111; /*
count(#####) */ } else ret = 999; /* count(#####) */ return ret; }
^
if (true_var_3 != 0)
m2.c:3:114: note: output_location
{ unsigned int true_var = 1; unsigned int false_var = 0; unsigned int ret = 0;
if (true_var) /* count(1) */ { if (false_var) /* count(1) */ ret = 111; /*
count(#####) */ } else ret = 999; /* count(#####) */ return ret; }
^
if (false_var_4 != 0)
m2.c:3:145: note: output_location
{ unsigned int true_var = 1; unsigned int false_var = 0; unsigned int ret = 0;
if (true_var) /* count(1) */ { if (false_var) /* count(1) */ ret = 111; /*
count(#####) */ } else ret = 999; /* count(#####) */ return ret; }
~~~~^~~~~
ret_7 = 111;
m2.c:3:182: note: output_location
{ unsigned int true_var = 1; unsigned int false_var = 0; unsigned int ret = 0;
if (true_var) /* count(1) */ { if (false_var) /* count(1) */ ret = 111; /*
count(#####) */ } else ret = 999; /* count(#####) */ return ret; }
~~~~^~~~~
ret_6 = 999;
m2.c:3:215: note: output_location
{ unsigned int true_var = 1; unsigned int false_var = 0; unsigned int ret = 0;
if (true_var) /* count(1) */ { if (false_var) /* count(1) */ ret = 111; /*
count(#####) */ } else ret = 999; /* count(#####) */ return ret; }
^~~
_8 = ret_2;
m2.c:3:215: note: output_location
# VUSE <.MEM_9(D)>
return _8;
Which is not optimal, for some assignments I see just LHS (false_var_4 = 0),
for return statements only a returned value is displayed. For conditions, only
condition beginning is showed.
Is this known behavior or do I miss something?
Thanks,
Martin
