gmp.h can't be found,or is unusable

[Hua Li]

Dear all,

I want to install GCC, and have to install GMP and MPFR first.

When I tried to install MPFR, there was an error: "gmp.h can't be
found,or is unusable". Then I checked GMP-5.0.4 (after
unpacked/configured), indeed, there is no gmp.h.

How can I generate gmp.h ?

Thanks a lot !
Hua