| Message ID | 20240625080332.1517736-3-j@lambda.is |
|---|---|
| State | New |
| Headers | show |
| Series | Condition coverage docs, bugfix | expand |
> gcc/ChangeLog: > > * doc/gcov.texi: Add MC/DC section. OK, thanks! Honza > --- > gcc/doc/gcov.texi | 72 +++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 72 insertions(+) > > diff --git a/gcc/doc/gcov.texi b/gcc/doc/gcov.texi > index dc79bccb8cf..a9221738cce 100644 > --- a/gcc/doc/gcov.texi > +++ b/gcc/doc/gcov.texi > @@ -917,6 +917,78 @@ of times the call was executed will be printed. This will usually be > 100%, but may be less for functions that call @code{exit} or @code{longjmp}, > and thus may not return every time they are called. > > +When you use the @option{-g} option, your output looks like this: > + > +@smallexample > +$ gcov -t -m -g tmp > + -: 0:Source:tmp.cpp > + -: 0:Graph:tmp.gcno > + -: 0:Data:tmp.gcda > + -: 0:Runs:1 > + -: 1:#include <stdio.h> > + -: 2: > + -: 3:int > + 1: 4:main (void) > + -: 5:@{ > + -: 6: int i, total; > + 1: 7: total = 0; > + -: 8: > + 11: 9: for (i = 0; i < 10; i++) > +condition outcomes covered 2/2 > + 10: 10: total += i; > + -: 11: > + 1*: 12: int v = total > 100 ? 1 : 2; > +condition outcomes covered 1/2 > +condition 0 not covered (true) > + -: 13: > + 1*: 14: if (total != 45 && v == 1) > +condition outcomes covered 1/4 > +condition 0 not covered (true) > +condition 1 not covered (true false) > + #####: 15: printf ("Failure\n"); > + -: 16: else > + 1: 17: printf ("Success\n"); > + 1: 18: return 0; > + -: 19:@} > +@end smallexample > + > +For every condition the number of taken and total outcomes are > +printed, and if there are uncovered outcomes a line will be printed > +for each condition showing the uncovered outcome in parentheses. > +Conditions are identified by their index -- index 0 is the left-most > +condition. In @code{a || (b && c)}, @var{a} is condition 0, @var{b} > +condition 1, and @var{c} condition 2. > + > +An outcome is considered covered if it has an independent effect on > +the decision, also known as masking MC/DC (Modified Condition/Decision > +Coverage). In this example the decision evaluates to true and @var{a} > +is evaluated, but not covered. This is because @var{a} cannot affect > +the decision independently -- both @var{a} and @var{b} must change > +value for the decision to change. > + > +@smallexample > +$ gcov -t -m -g tmp > + -: 0:Source:tmp.c > + -: 0:Graph:tmp.gcno > + -: 0:Data:tmp.gcda > + -: 0:Runs:1 > + -: 1:#include <stdio.h> > + -: 2: > + 1: 3:int main() > + -: 4:@{ > + 1: 5: int a = 1; > + 1: 6: int b = 0; > + -: 7: > + 1: 8: if (a && b) > +condition outcomes covered 1/4 > +condition 0 not covered (true false) > +condition 1 not covered (true) > + #####: 9: printf ("Success!\n"); > + -: 10: else > + 1: 11: printf ("Failure!\n"); > + -: 12:@} > +@end smallexample > + > The execution counts are cumulative. If the example program were > executed again without removing the @file{.gcda} file, the count for the > number of times each line in the source was executed would be added to > -- > 2.39.2 >
On 6/25/24 12:23, Jan Hubicka wrote: >> gcc/ChangeLog: >> >> * doc/gcov.texi: Add MC/DC section. > OK, > thanks! Pushed. Thanks, Jørgen > Honza >> --- >> gcc/doc/gcov.texi | 72 +++++++++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 72 insertions(+) >> >> diff --git a/gcc/doc/gcov.texi b/gcc/doc/gcov.texi >> index dc79bccb8cf..a9221738cce 100644 >> --- a/gcc/doc/gcov.texi >> +++ b/gcc/doc/gcov.texi >> @@ -917,6 +917,78 @@ of times the call was executed will be printed. This will usually be >> 100%, but may be less for functions that call @code{exit} or @code{longjmp}, >> and thus may not return every time they are called. >> >> +When you use the @option{-g} option, your output looks like this: >> + >> +@smallexample >> +$ gcov -t -m -g tmp >> + -: 0:Source:tmp.cpp >> + -: 0:Graph:tmp.gcno >> + -: 0:Data:tmp.gcda >> + -: 0:Runs:1 >> + -: 1:#include <stdio.h> >> + -: 2: >> + -: 3:int >> + 1: 4:main (void) >> + -: 5:@{ >> + -: 6: int i, total; >> + 1: 7: total = 0; >> + -: 8: >> + 11: 9: for (i = 0; i < 10; i++) >> +condition outcomes covered 2/2 >> + 10: 10: total += i; >> + -: 11: >> + 1*: 12: int v = total > 100 ? 1 : 2; >> +condition outcomes covered 1/2 >> +condition 0 not covered (true) >> + -: 13: >> + 1*: 14: if (total != 45 && v == 1) >> +condition outcomes covered 1/4 >> +condition 0 not covered (true) >> +condition 1 not covered (true false) >> + #####: 15: printf ("Failure\n"); >> + -: 16: else >> + 1: 17: printf ("Success\n"); >> + 1: 18: return 0; >> + -: 19:@} >> +@end smallexample >> + >> +For every condition the number of taken and total outcomes are >> +printed, and if there are uncovered outcomes a line will be printed >> +for each condition showing the uncovered outcome in parentheses. >> +Conditions are identified by their index -- index 0 is the left-most >> +condition. In @code{a || (b && c)}, @var{a} is condition 0, @var{b} >> +condition 1, and @var{c} condition 2. >> + >> +An outcome is considered covered if it has an independent effect on >> +the decision, also known as masking MC/DC (Modified Condition/Decision >> +Coverage). In this example the decision evaluates to true and @var{a} >> +is evaluated, but not covered. This is because @var{a} cannot affect >> +the decision independently -- both @var{a} and @var{b} must change >> +value for the decision to change. >> + >> +@smallexample >> +$ gcov -t -m -g tmp >> + -: 0:Source:tmp.c >> + -: 0:Graph:tmp.gcno >> + -: 0:Data:tmp.gcda >> + -: 0:Runs:1 >> + -: 1:#include <stdio.h> >> + -: 2: >> + 1: 3:int main() >> + -: 4:@{ >> + 1: 5: int a = 1; >> + 1: 6: int b = 0; >> + -: 7: >> + 1: 8: if (a && b) >> +condition outcomes covered 1/4 >> +condition 0 not covered (true false) >> +condition 1 not covered (true) >> + #####: 9: printf ("Success!\n"); >> + -: 10: else >> + 1: 11: printf ("Failure!\n"); >> + -: 12:@} >> +@end smallexample >> + >> The execution counts are cumulative. If the example program were >> executed again without removing the @file{.gcda} file, the count for the >> number of times each line in the source was executed would be added to >> -- >> 2.39.2 >>
diff --git a/gcc/doc/gcov.texi b/gcc/doc/gcov.texi index dc79bccb8cf..a9221738cce 100644 --- a/gcc/doc/gcov.texi +++ b/gcc/doc/gcov.texi @@ -917,6 +917,78 @@ of times the call was executed will be printed. This will usually be 100%, but may be less for functions that call @code{exit} or @code{longjmp}, and thus may not return every time they are called. +When you use the @option{-g} option, your output looks like this: + +@smallexample +$ gcov -t -m -g tmp + -: 0:Source:tmp.cpp + -: 0:Graph:tmp.gcno + -: 0:Data:tmp.gcda + -: 0:Runs:1 + -: 1:#include <stdio.h> + -: 2: + -: 3:int + 1: 4:main (void) + -: 5:@{ + -: 6: int i, total; + 1: 7: total = 0; + -: 8: + 11: 9: for (i = 0; i < 10; i++) +condition outcomes covered 2/2 + 10: 10: total += i; + -: 11: + 1*: 12: int v = total > 100 ? 1 : 2; +condition outcomes covered 1/2 +condition 0 not covered (true) + -: 13: + 1*: 14: if (total != 45 && v == 1) +condition outcomes covered 1/4 +condition 0 not covered (true) +condition 1 not covered (true false) + #####: 15: printf ("Failure\n"); + -: 16: else + 1: 17: printf ("Success\n"); + 1: 18: return 0; + -: 19:@} +@end smallexample + +For every condition the number of taken and total outcomes are +printed, and if there are uncovered outcomes a line will be printed +for each condition showing the uncovered outcome in parentheses. +Conditions are identified by their index -- index 0 is the left-most +condition. In @code{a || (b && c)}, @var{a} is condition 0, @var{b} +condition 1, and @var{c} condition 2. + +An outcome is considered covered if it has an independent effect on +the decision, also known as masking MC/DC (Modified Condition/Decision +Coverage). In this example the decision evaluates to true and @var{a} +is evaluated, but not covered. This is because @var{a} cannot affect +the decision independently -- both @var{a} and @var{b} must change +value for the decision to change. + +@smallexample +$ gcov -t -m -g tmp + -: 0:Source:tmp.c + -: 0:Graph:tmp.gcno + -: 0:Data:tmp.gcda + -: 0:Runs:1 + -: 1:#include <stdio.h> + -: 2: + 1: 3:int main() + -: 4:@{ + 1: 5: int a = 1; + 1: 6: int b = 0; + -: 7: + 1: 8: if (a && b) +condition outcomes covered 1/4 +condition 0 not covered (true false) +condition 1 not covered (true) + #####: 9: printf ("Success!\n"); + -: 10: else + 1: 11: printf ("Failure!\n"); + -: 12:@} +@end smallexample + The execution counts are cumulative. If the example program were executed again without removing the @file{.gcda} file, the count for the number of times each line in the source was executed would be added to