[clang-format] wrong formatting when C++ keywords are used as variable name in C

[kleisauke]

For example:

void test() {
  int *p;
  
  int and, and_eq, bitand, bitor, compl, not, not_eq, or, or_eq, xor,
      xor_eq = 1;

  p = ∧
  p = &and_eq;
  p = &bitand;
  p = &bitor;
  p = &compl;
  p = ¬
  p = &not_eq;
  p = ∨
  p = &or_eq;
  p = &xor;
  p = &xor_eq;
}

int main() {
  int *and, *and_eq, *bitand, *bitor, *compl, *not, *not_eq, *or, *or_eq,
      *xor, *xor_eq = 0;
}

Is incorrectly formatted as:

void test() {
  int *p;

  int and, and_eq, bitand, bitor, compl, not, not_eq, or, or_eq, xor,
      xor_eq = 1;

  p = ∧
  p = & and_eq ;
  p = &bitand;
  p = & bitor ;
  p = &compl ;
  p = &not ;
  p = & not_eq ;
  p = & or ;
  p = & or_eq ;
  p = &xor;
  p = & xor_eq ;
}

int main() {
  int *and, * and_eq, *bitand, * bitor, *compl, *not, * not_eq, * or, * or_eq,
      *xor, * xor_eq = 0;
}

(note that and, bitand, compl, not and xor is somehow unaffected)

Tested with the latest revision (commit 409f0dc at the time of writing):

$ clang-format --version
clang-format version 16.0.0 (https://github.com/llvm/llvm-project.git 409f0dc4a420db1c6b259d5ae965a070c169d930)
$ clang-format -style=llvm test.c

(For the same reason, the lldb/test/API/lang/c/cpp_keyword_identifiers/main.c file is probably excluded for clang-format)

[llvmbot]

@llvm/issue-subscribers-clang-format

[rymiel]

similar to #25697 and #43678 and #53173

[kleisauke]

similar to #25697 and #43678 and #53173

It looks like the first two issues are duplicates of each other and have already been fixed with commit d1aed48, the last issue concerns only the interface keyword.

Issue #46915 (and #56249) are also similar here (i.e. it adds a unnecessary space), these were fixed with commit dbc4d28.

I responded to the linked issues that did not include references to these commits. If necessary, I could split this issue into separate ones, but I think in terms of code the change is happening in the same area.

[rymiel]

Sorry, the issue description just sounded familiar so I made a quick search, not checking if they were fixed. I'll close those ones.

[Tamaranch]

Another buggy keyword is new: for example clang-format outputs

int maximized = new &STATE_MAXIMIZED;

instead of

int maximized = new & STATE_MAXIMIZED;

[owenca]

Fixed by #128287.

[owenca]

Another buggy keyword is new: for example clang-format outputs

int maximized = new &STATE_MAXIMIZED;
instead of

int maximized = new & STATE_MAXIMIZED;

Please split it to another issue.

[Tamaranch]

Please split it to another issue.

Isn't this also fixed by #128287? There doesn't seem to be an easy way to test clang-git on arch linux unfortunately, and I can't build the whole thing myself.

[owenca]

No, because new is not one of the C++ alternative operator keywords.