[LLVM-COV] Coverage errors caused by macro definitions

[zhangxy-97]

The macro variable N is used in the If conditional statement, causing line 12 to be incorrectly marked as being executed once.

$ clang -v

clang version 11.0.0
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/bin
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.4.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/9.3.0
Found candidate GCC installation: /usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/10.2.0
Selected GCC installation: /usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/10.2.0
Candidate multilib: .;@m64
Selected multilib: .;@m64

Source code:

    1|      1|#define N 1
    2|      0|#define TRUE 1
    3|       |#include <stdlib.h>
    4|      0|#define ADD(a,b) a + b
    5|       |
    6|      0|void myExit() { exit(0); }
    7|       |
    8|       |int zero = 0;
    9|       |int tmp = 0;
   10|      1|int main() {
   11|      1|   if (zero > N) 
   12|      1|      return 0;
   13|      1|   else {
   14|      1|      exit(0);
   15|      1|   }
   16|      0|   if (zero > N) {
   17|      0|      myExit();
   18|      0|      tmp = TRUE;
   19|      0|   } else
   20|      0|      myExit();
   21|      0|   
   22|      0|   if (ADD(1, 2) != ADD(2, 1)) {
   23|      0|      ;
   24|      0|   }
   25|      0|}

In addition, the termination instruction should only be executed once in the main function, and line 12 should be marked as unexecuted.