To get the list of g++ warnings:
g++ --help=warnings
To get the list of clang++ warnings, see Diagnostic flags in Clang.
Generally all warnings flags which g++ implements will be implemented by clang++. BUT they might be implemented differently (and hence triggered on slightly different conditions).
See: Clang tools
See: Clang-tidy
See: Clang-Tidy
See: Clang-check
See: