[clang-format] AllowShortFunctionsOnASingleLine=Inline does not respect macros

[rafzi]

I stumbled upon #60627 which describes this same issue. Over there, the conclusion seems to be wont-fix because the intention of the related change (https://reviews.llvm.org/D117142) was to fix exactly the reported case.

However, I'd argue that a slight modification to the example is an unintended regression. If macros hide the "class" token, the scope is not correctly detected.

#define MY_THING(name) class name##Thing final
MY_THING(Foo)
{
    int func() { return 7; }
}

is formatted to:

#define MY_THING(name) class name##Thing final
MY_THING(Foo)
{
    int func()
    {
        return 7;
    }
}

[llvmbot]

@llvm/issue-subscribers-clang-format

Author: Rafael Stahl (rafzi)

I stumbled upon https://github.com//issues/60627 which describes this same issue. Over there, the conclusion seems to be wont-fix because the intention of the related change (https://reviews.llvm.org/D117142) was to fix exactly the reported case.

However, I'd argue that a slight modification to the example is an unintended regression. If macros hide the "class" token, the scope is not correctly detected.

#define MY_THING(name) class name##Thing final
MY_THING(Foo)
{
    int func() { return 7; }
}

is formatted to:

#define MY_THING(name) class name##Thing final
MY_THING(Foo)
{
    int func()
    {
        return 7;
    }
}

[owenca]

clang-format needs to know what the macro is about:

$ cat a.cc
MY_THING(Foo) {
  int func() { return 7; }
}
$ cat .clang-format
AllowShortFunctionsOnASingleLine: Inline
Macros: [MY_THING(a)=class a]
$ clang-format -version
clang-format version 20.1.1
$ clang-format a.cc | diff a.cc -
$