[PATCH] D23160: [Coverage] Prevent creating a redundant counter if a nested body ends with a macro.

[Igor Kudrin via cfe-commits]

ikudrin added a comment.

The motivation sample:

  $ cat > test.cpp << EOF
  void dummy() {}
  
  #define MACRO dummy()
  
  int main()
  {
    int i = 0;
    while (i++ < 10)
      if (i < 5)
        MACRO;
    return 0;
  }
  EOF
  $ clang++ -fprofile-instr-generate -fcoverage-mapping dummy.cpp test.cpp
  $ ./a.out
  $ llvm-profdata merge -o default.profdata default.profraw
  $ llvm-cov show a.out -instr-profile --show-expansions default.profdata
  test.cpp:
        4|    1|void dummy() {}
         |    2|
       14|    3|#define MACRO dummy()
         |    4|
         |    5|int main()
        1|    6|{
        1|    7|  int i = 0;
       11|    8|  while (i++ < 10)
       10|    9|    if (i < 5)
        4|   10|      MACRO;
    ------------------
    |  |     14|    3|#define MACRO dummy()
    ------------------
        1|   11|  return 0;
        1|   12|}

After applying this patch the counter for MACRO shows a reasonable value:

  $ llvm-cov show a.out -instr-profile --show-expansions default.profdata
  test.cpp:
        4|    1|void dummy() {}
         |    2|
        4|    3|#define MACRO dummy()
         |    4|
         |    5|int main()
        1|    6|{
        1|    7|  int i = 0;
       11|    8|  while (i++ < 10)
       10|    9|    if (i < 5)
        4|   10|      MACRO;
    ------------------
    |  |      4|    3|#define MACRO dummy()
    ------------------
        1|   11|  return 0;
        1|   12|}


https://reviews.llvm.org/D23160