"// clang-format off" comment should not be formatted

[sylvestre]

Bugzilla Link	39280
Version	unspecified
OS	Linux
CC	@aardappel,@abpostelnicu

Extended Description

with this code:

static const uint32_t gWinEventMap[] = {
  // clang-format off
  1,
  2,
  3
// clang-format on
};

% clang-format-7 foo.cpp
returns:

static const uint32_t gWinEventMap[] = {
    // clang-format off
  1,
  2,
  3
    // clang-format on
};

Because // clang-format off is all about disabling coding style, I believe we should not touch this comment.

[aardappel]

Similarly:

---

void f() {
...
// clang-format off
#ifdef X
...
#endif
// clang-format off
}

Returns:

---

void f() {
...
// clang-format off
#ifdef X
...
#endif
// clang-format off
}

Ironically, using clang-format off to preserve indentation.. does not preserve indentation on itself.

Workaround for this bug: add a newline:

---

void f() {
...
// clang-format off

#ifdef X
...
#endif
// clang-format off
}

Of course, the use of clang-format off here is a work-around for bugs #35368 and #35367 , so fixing those would work too :)

[aardappel]

Ok, in addition, clang-format is not quite sure what it prefers: if you run clang-format TWICE over the same file, it will undo the problem it created as described in this bug.

E.g. the code ends up transformed from the second code-block in my last comment back in the first.

At least we now know for sure it is a bug :)

[llvmbot]

Twice running clang-format may give unstable result for some code samples
https://reviews.llvm.org/D53482

[owenca]

Formatting is turned off after // clang-format off as it should be IMO. Otherwise, it works as expected in 20.1.7.