[clang-format] Incorrect formatting for annotated constrained functions

[usx95]

clang-format's output:

#define ANNOTATE(A) [[clang::annotate(A)]]
template <typename Message>
    requires(true)
ANNOTATE(
    "Loooooooooooooooooooooooooooooooooooooooooooooooooooong message"
    "Loooooooooooooooooooooooooooooooooooooooooooooooooooong message"
    "message") void foo(){};

Expected formatting:

#define ANNOTATE(A) [[clang::annotate(A)]]
template <typename Message>
    requires(true)
ANNOTATE(
    "Loooooooooooooooooooooooooooooooooooooooooooooooooooong message"
    "Loooooooooooooooooooooooooooooooooooooooooooooooooooong message"
    "message") 
void foo(){};

removing the requires clause fixes the formatting (moved void foo() to the next line).

[llvmbot]

@llvm/issue-subscribers-clang-format

Author: Utkarsh Saxena (usx95)

clang-format's output: ``` #define ANNOTATE(A) [[clang::annotate(A)]] template <typename Message> requires(true) ANNOTATE( "Loooooooooooooooooooooooooooooooooooooooooooooooooooong message" "Loooooooooooooooooooooooooooooooooooooooooooooooooooong message" "message") void foo(){}; ``` Expected formatting: ``` #define ANNOTATE(A) [[clang::annotate(A)]] template <typename Message> requires(true) ANNOTATE( "Loooooooooooooooooooooooooooooooooooooooooooooooooooong message" "Loooooooooooooooooooooooooooooooooooooooooooooooooooong message" "message") void foo(){}; ```

removing the requires clause fixes the formatting (moved void foo() to the next line).

[llvmbot]

@llvm/issue-subscribers-c-20

Author: Utkarsh Saxena (usx95)

clang-format's output: ``` #define ANNOTATE(A) [[clang::annotate(A)]] template <typename Message> requires(true) ANNOTATE( "Loooooooooooooooooooooooooooooooooooooooooooooooooooong message" "Loooooooooooooooooooooooooooooooooooooooooooooooooooong message" "message") void foo(){}; ``` Expected formatting: ``` #define ANNOTATE(A) [[clang::annotate(A)]] template <typename Message> requires(true) ANNOTATE( "Loooooooooooooooooooooooooooooooooooooooooooooooooooong message" "Loooooooooooooooooooooooooooooooooooooooooooooooooooong message" "message") void foo(){}; ```

removing the requires clause fixes the formatting (moved void foo() to the next line).

[usx95]

+CC @rymiel @HazardyKnusperkeks

[HazardyKnusperkeks]

I'll take a look what's the difference. In the meantime maybe https://clang.llvm.org/docs/ClangFormatStyleOptions.html#macros could help you.

[owenca]

The clang-format settings below would work:

BreakAfterAttributes: Always
Macros:
- ANNOTATE(x)=[[a(x)]]

[usx95]

I think the problem is that we do not want to "always" have a break (for example, when the annotation is small enough).

The problem is that the existence of a requires clause removes the line break, which looks unexpected.

[HazardyKnusperkeks]

I'd say we have two issues here. One is that it is handled differently with the requires clause. But the bigger issue would be that foo is misannotated in both cases:

 M=0 C=1 T=Unknown S=1 F=0 B=0 BK=0 P=23 Name=void L=120 PPK=2 FakeLParens= FakeRParens=0 II=0x559e1e3dbcb0 Text='void'
 M=0 C=0 T=TrailingAnnotation S=1 F=0 B=0 BK=0 P=23 Name=identifier L=124 PPK=2 FakeLParens= FakeRParens=0 II=0x559e1e4205e0 Text='foo'

I'll try to fix the second issue, and then we'll see if the first is still around.

[HazardyKnusperkeks]

If you declare your ANNOTATE as AttributeMacros both variants have no line break before void, but after that. ;)

[owenca]

I think the problem is that we do not want to "always" have a break (for example, when the annotation is small enough).

Then setting it to Leave would work, right?

[HazardyKnusperkeks]

So I actually corrected the first issue. The second issue will be tracked in #70603.