[clang] Support unnamed parameters in -Wdocumentation

[carlosgalvezp]

Currently -Wdocumentation does not support unnamed parameters, since it requires that a name is present. For example:

/// @param some unnamed parameter
/// @param y something 
void f(int, int y) {}

It fails with:

<source>:1:12: warning: parameter 'some' not found in the function declaration [-Wdocumentation]
    1 | /// @param some unnamed parameter
      |            ^~~~

https://godbolt.org/z/efqxdTTjb

It would be great if this use case could be supported in some way. In a relevant Doxygen thread they propose using an integer to identify the unnamed parameter:

/// @param 1 some unnamed parameter

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Carlos Galvez (carlosgalvezp)

Details

Currently -Wdocumentation does not support unnamed parameters, since it requires that a name is present. For example:

/// @<!-- -->param some unnamed parameter
/// @<!-- -->param y something 
void f(int, int y) {}

It fails with:

<source>:1:12: warning: parameter 'some' not found in the function declaration [-Wdocumentation]
    1 | /// @<!-- -->param some unnamed parameter
      |            ^~~~

https://godbolt.org/z/efqxdTTjb

It would be great if this use case could be supported in some way. In a relevant Doxygen thread they propose using an integer to identify the unnamed parameter:

@<!-- -->param 1 some unnamed parameter