Add clang-format option for formatting single statement function on one line with braces

[void2012]

Hello! I want to format my C++ code with custom formatting style specified in .clang-format file. The clang-format documentation says there is an option that allows to put short function bodies on the same line with functions.
https://clang.llvm.org/docs/ClangFormatStyleOptions.html#allowshortfunctionsonasingleline
However, this is not what I want. I want the function body braces to be put on the same line with function body itself, not the whole thing with signature.

With AllowShortFunctionsOnASingleLine: All:

inline const char* GetBuildingName(TTownType townType, type_building_id buildingId) { return FASTCALL_2(const char*, 0x460CC0, townType, buildingId); } // everything on the same line, ugly

With AllowShortFunctionsOnASingleLine: None:

inline const char* GetBuildingName(TTownType townType, type_building_id buildingId)
{ 
return FASTCALL_2(const char*, 0x460CC0, townType, buildingId); // I need it on the single line
}

Desired behavior:

inline const char* GetBuildingName(TTownType townType, type_building_id buildingId)
{ return FASTCALL_2(const char*, 0x460CC0, townType, buildingId); } // what I want, but only for single-line body functions

It would be also great to have such an option for structs/classes that contain only a single line of code inside their bodies. Thanks!

[llvmbot]

@llvm/issue-subscribers-clang-format

Author: void_17 (void2012)

Hello! I want to format my C++ code with custom formatting style specified in .clang-format file. The clang-format documentation says there is an option that allows to put short function bodies on the same line with functions. https://clang.llvm.org/docs/ClangFormatStyleOptions.html#allowshortfunctionsonasingleline However, this is not what I want. I want the function body braces to be put on the same line with function body itself, not the whole thing with signature.

With AllowShortFunctionsOnASingleLine: All:

inline const char* GetBuildingName(TTownType townType, type_building_id buildingId) { return FASTCALL_2(const char*, 0x460CC0, townType, buildingId); } // everything on the same line, ugly

With AllowShortFunctionsOnASingleLine: None:

inline const char* GetBuildingName(TTownType townType, type_building_id buildingId)
{ 
return FASTCALL_2(const char*, 0x460CC0, townType, buildingId); // I need it on the single line
}

Desired behavior:

inline const char* GetBuildingName(TTownType townType, type_building_id buildingId)
{ return FASTCALL_2(const char*, 0x460CC0, townType, buildingId); } // what I want, but only for single-line body functions

It would be also great to have such an option for structs/classes that contain only a single line of code inside their bodies. Thanks!

[brandb97]

Maybe we can solve this by adding an AllowShortFunctionBodyOnSingleLine option. I'm interested in clang-format right now and would love to work on this—would it be okay to assign it to me?

[owenca]

It seems that we have a bug in AllowShortBlocksOnASingleLine: Always:

$ cat a.cc
void f() { return; }
$ cat .clang-format
AllowShortBlocksOnASingleLine: Always
AllowShortFunctionsOnASingleLine: None
$ clang-format -version
clang-format version 20.1.8
$ clang-format a.cc
void f() {
  return;
}

Expected format:

void f()
{ return; }

[brandb97]

Thanks, I will try to look into AllowShortBlocksOnASingleLine: Always.

[owenca]

It seems that we have a bug in AllowShortBlocksOnASingleLine: Always:

$ cat a.cc
void f() { return; }
$ cat .clang-format
AllowShortBlocksOnASingleLine: Always
AllowShortFunctionsOnASingleLine: None
$ clang-format -version
clang-format version 20.1.8
$ clang-format a.cc
void f() {
  return;
}

Expected format:

void f()
{ return; }

I just realized that it wasn't a bug unless BraceWrapping.AfterFunction is set:

AllowShortBlocksOnASingleLine: Always
AllowShortFunctionsOnASingleLine: None
BreakBeforeBraces: Custom
BraceWrapping:
  AfterFunction: true