Format struct/class-like macros to preserve semicolon at the end

[Alexolut]

I have macro like this

#define STRUCT(TYPE) struct TYPE : public Base

that is used as the following:

STRUCT(MyName) {
    // a lot of members (functions, data)
};

I would like to leave the code above as-is after clang-formating.

In particular I have following options in my .clang-format file:

BraceWrapping:
  AfterControlStatement: Never
# ...
RemoveSemicolon: true
SpaceBeforeParens: Custom
SpaceBeforeParensOptions:
  AfterControlStatements: true
# ...

The only way I found to preserve semicolon here is to add macro STRUCT to the list of IfMacros and disable space for them:

IfMacros:
  - STRUCT
SpaceBeforeParensOptions:
  AfterIfMacros:   false

But to be fair STRUCT is not an IfMacro. It's more likely TypenameMacros, but unfortunately I didn't find how to achieve that with TypenameMacros. What am I missing? I use LLVM 18.1.7

[llvmbot]

@llvm/issue-subscribers-clang-format

Author: None (Alexolut)

I have macro like this

#define STRUCT(TYPE) struct TYPE : public Base

that is used as the following:

STRUCT(MyName) {
    // a lot of members (functions, data)
};

I would like to leave the code above as-is after clang-formating.

In particular I have following options in my .clang-format file:

BraceWrapping:
  AfterControlStatement: Never
# ...
RemoveSemicolon: true
SpaceBeforeParens: Custom
SpaceBeforeParensOptions:
  AfterControlStatements: true
# ...

The only way I found to preserve semicolon here is to add macro STRUCT to the list of IfMacros and disable space for them:

IfMacros:
  - STRUCT
SpaceBeforeParensOptions:
  AfterIfMacros:   false

But to be fair STRUCT is not an IfMacro. It's more likely TypenameMacros, but unfortunately I didn't find how to achieve that with TypenameMacros. What am I missing? I use LLVM 18.1.7

[owenca]

The semicolon is not removed for me:

$ cat .clang-format
BraceWrapping:
  AfterControlStatement: Never
# ...
BreakBeforeBraces: Custom
RemoveSemicolon: true
SpaceBeforeParens: Custom
SpaceBeforeParensOptions:
  AfterControlStatements: true
$ cat input.cpp
#define STRUCT(TYPE) struct TYPE : public Base

STRUCT(MyName) {
    // a lot of members (functions, data)
};
$ clang-format -version
clang-format version 18.1.7
$ clang-format input.cpp | diff input.cpp -
3c3
< STRUCT(MyName) {
---
> STRUCT(MyName){
$ 

However, you need to use Macros instead of IfMacros:

$ cat .clang-format
BraceWrapping:
  AfterControlStatement: Never
# ...
BreakBeforeBraces: Custom
Macros:
  - STRUCT(x)=struct x
RemoveSemicolon: true
SpaceBeforeParens: Custom
SpaceBeforeParensOptions:
  AfterControlStatements: true
$ clang-format input.cpp | diff input.cpp -
4c4
<     // a lot of members (functions, data)
---
>   // a lot of members (functions, data)
$ 

[Alexolut]

I made some extra investigations and found that my actual macro has two params, i.e. code looks like this:

#define STRUCT(Type, Base) struct Type : public Base

STRUCT(T, B) {
    int i;
};

According documentation:

Overloading by arity is supported: for example, given the macro definitions A=x, A()=y, A(a)=a

A; -> x;
A(); -> y;
A(z); -> z;
A(a, b); // will not be expanded.

But if I use the following in .clang-format file:

Macros:
  - STRUCT(x, y)=struct x : y

I got an runtime error during the formatting:

.clang-format:253:5: error: unexpected scalar
  - STRUCT(x, y)=struct x : y
    ^
Error reading C:\myproj\.clang-format: invalid argument

[owenca]

I made some extra investigations and found that my actual macro has two params, i.e. code looks like this:

#define STRUCT(Type, Base) struct Type : public Base

STRUCT(T, B) {
    int i;
};

According documentation:

Overloading by arity is supported: for example, given the macro definitions A=x, A()=y, A(a)=a

A; -> x;
A(); -> y;
A(z); -> z;
A(a, b); // will not be expanded.

But if I use the following in .clang-format file:

Macros:
  - STRUCT(x, y)=struct x : y

With the patch in #96026, you can do the following instead:

TypenameMacros:
  - STRUCT