Extended Description

$ clang -v
clang version 6.0.0-svn318792-1~exp1 (trunk)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.1
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/6.3.0
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/7.2.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.4.1
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.3.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.2.0
Selected GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/7.2.0
Candidate multilib: .;@m64
Selected multilib: .;@m64

$ cat small.c
int main()
{
int i=1, j=1, k=1;
if (i > 0) {
if (j == 1) {
if (k == 1)
return 0;
else
goto lbl;
} else {
;
}
}
lbl:
return 1;
}

$ clang -w -O0 -g -fcoverage-mapping -fprofile-instr-generate=small.profraw small.c; ./a.out; llvm-profdata merge small.profraw -o small.profdata; llvm-cov show a.out -instr-profile=small.profdata small.c > small.gcov

$ cat small.gcov
1| |int main()
2| 1|{
3| 1| int i=1, j=1, k=1;
4| 1| if (i > 0) {
5| 1| if (j == 1) {
6| 1| if (k == 1)
7| 1| return 0;
8| 0| else
9| 0| goto lbl;
10| 0| } else {
11| 0| ;
12| 0| }
13| 1| }
14| 1|lbl:
15| 0| return 1;
16| 0|}

Line #​14 is a label. The goto statement is not executed. However, it was wrongly marked as executed in llvm-cov. While removing Line #​10 and #​11 from this code, this result is correct.