clang-format - incorrect formating of macros

[DmitrySokolov]

clang-format version 11.0.0 (https://github.com/llvm/llvm-project.git 7420f96)

---
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...

test.cpp

#define FUNC_BEGIN(name, ret) \
  struct Class_##name { \
    static ret run (void *ctx) { \
        return ((Class_##name*)ctx)->operator()(); \
    } \
    inline ret operator() () {

#define FUNC_END(name) \
    } \
 \
    Class_##name()  {} \
  }; \
  Class_##name name;

test_actual.cpp

#define FUNC_BEGIN(name, ret)                                                    \
    struct Class_##name                                                          \
    {                                                                            \
        static ret run(void* ctx) { return ((Class_##name*)ctx)->operator()(); } \
        inline ret operator()() { #define FUNC_END(name) }                       \
                                                                                 \
    Class_##name() {}                                                            \
    }                                                                            \
    ;                                                                            \
    Class_##name name;

test_expected.cpp

#define FUNC_BEGIN(name, ret)                    \
  struct Class_##name {                          \
    static ret run (void *ctx) {                 \
      return ((Class_##name*)ctx)->operator()(); \
    }                                            \
    inline ret operator() () {

#define FUNC_END(name) \
    }                  \
                       \
    Class_##name()  {} \
  };                   \
  Class_##name name;

[rymiel]

This issue seems to describe invalid-code-generation when it comes to macros. This was fixed by ca0d970 as part of clang-format 15

The output with a modern version is the following:

#define FUNC_BEGIN(name, ret)                          \
    struct Class_##name                                \
    {                                                  \
        static ret run(void* ctx)                      \
        {                                              \
            return ((Class_##name*)ctx)->operator()(); \
        }                                              \
        inline ret operator()()                        \
        {
#define FUNC_END(name) \
    }                  \
                       \
    Class_##name()     \
    {}                 \
    }                  \
    ;                  \
    Class_##name name;

Which doesn't match the expected output, but it at least doesn't break compilation. I don't think clang-format can do much better when it comes to incomplete code fragments, but the invalid-code-generation is fixed