Where is the manpage of otools gcc etc. on macOS? Many tools related with binaries, such otools, gcc, don't have manpages on my macOS (10.13.6). Is there a way to install the manpages for them?
This answer from stackoverflow says that gcc is not installed by default on mac. Instead it installs clang and calls it gcc.

usxxplayegm1:~ grady$ which gcc
/usr/bin/gcc

usxxplayegm1:~ grady$ /usr/bin/gcc --version

Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 5.1 (clang-503.0.38) (based on LLVM 3.4svn)
Target: x86_64-apple-darwin13.0.2
Thread model: posix


you need man clang. Alternatively, if you want help regarding gcc, you can use gcc --help