detail the language option

the -x command hints is too simple

-x language

Specify explicitly the language for the following input files (rather than letting the compiler choose a default based on the file name suffix). This option applies to all following input files until the next ‘-x’ option. Possible values for language are:
c c-header cpp-output c++ c++-cpp-output objective-c objc-cpp-output assembler assembler-with-cpp ada f77 f77-cpp-input ratfor java treelang

Something like this should be better. So what kinds of clang -x language support? I want a list and add it to the option TD

All of clang’s --help is very terse, and I don’t think calling out -x really helps things.

Unfortunately, to my knowledge, clang doesn’t have comprehensive documentation for its options. The closest thing we have is:
http://clang.llvm.org/docs/UsersManual.html#command-line-options
… but it’s not complete and full of TODOs.

If it’s a gcc and clang option, we usually direct users to the gcc documentation, which works in this case.

All of clang's --help is very terse, and I don't think calling out -x
really helps things.

I wanna to help to improve clang's --help, -x could be a start point, so I
wanna to know for these languages, which are supported:

c c-header cpp-output c++ c++-cpp-output objective-c objc-cpp-output
assembler assembler-with-cpp ada f77 f77-cpp-input ratfor java treelang
besides, is there any othere language-style that clang supported?