Document minimal compiler requirements

[jamesthesken]

Had a hard time building both Aleth and Solidity, which were getting stuck on make.

Realized I should upgrade my GCC to a more current version, I had the initial configuration of:

• Ubuntu 16.04
• GCC/G++ 5.4.0
• clang version 3.8.0
• Boost 1.71

I then upgraded to G++ 6.5.0 and it is building successfully.

Ironically I wanted to contribute so I think this is a good starting point! Maybe I can update the documentation? @gumb0

[ 3%] Built target mpir [ 6%] Built target secp256k1 [ 6%] Built target aleth-buildinfo-git [ 7%] Built target aleth-buildinfo [ 10%] Built target libff [ 14%] Built target binaryen [ 15%] Built target instructions [ 16%] Built target loader [ 16%] Building CXX object libaleth-interpreter/CMakeFiles/aleth-interpreter.dir/VM.cpp.o In file included from /home/jthesken/aleth/libaleth-interpreter/VM.h:9:0, from /home/jthesken/aleth/libaleth-interpreter/VM.cpp:5: /home/jthesken/.hunter/_Base/c022f0c/a18bfa6/02f0220/Install/include/intx/intx.hpp: In member function ‘void dev::eth::VM::interpretCases()’: /home/jthesken/aleth/libaleth-interpreter/VM.cpp:764:46: in constexpr expansion of ‘intx::operator""_u256(((const char*)"1"))’ /home/jthesken/.hunter/_Base/c022f0c/a18bfa6/02f0220/Install/include/intx/intx.hpp:961:34: error: ‘constexpr Int intx::from_string(const char*) [with Int = intx::uint<256u>]’ called in a constant expression return from_string<uint256>(s); ^ In file included from /home/jthesken/.hunter/_Base/c022f0c/a18bfa6/02f0220/Install/include/intx/intx.hpp:7:0, from /home/jthesken/aleth/libaleth-interpreter/VM.h:9, from /home/jthesken/aleth/libaleth-interpreter/VM.cpp:5: /home/jthesken/.hunter/_Base/c022f0c/a18bfa6/02f0220/Install/include/intx/int128.hpp:749:15: note: ‘constexpr Int intx::from_string(const char*) [with Int = intx::uint<256u>]’ is not usable as a constexpr function because: constexpr Int from_string(const char* s) ^ /home/jthesken/.hunter/_Base/c022f0c/a18bfa6/02f0220/Install/include/intx/int128.hpp:749:15: sorry, unimplemented: unexpected AST of kind loop_expr /home/jthesken/.hunter/_Base/c022f0c/a18bfa6/02f0220/Install/include/intx/int128.hpp:749: confused by earlier errors, bailing out libaleth-interpreter/CMakeFiles/aleth-interpreter.dir/build.make:62: recipe for target 'libaleth-interpreter/CMakeFiles/aleth-interpreter.dir/VM.cpp.o' failed make[2]: *** [libaleth-interpreter/CMakeFiles/aleth-interpreter.dir/VM.cpp.o] Error 1 CMakeFiles/Makefile2:444: recipe for target 'libaleth-interpreter/CMakeFiles/aleth-interpreter.dir/all' failed make[1]: *** [libaleth-interpreter/CMakeFiles/aleth-interpreter.dir/all] Error 2 Makefile:162: recipe for target 'all' failed make: *** [all] Error 2

[gumb0]

@chfast Do we have compiler requirements listed somewhere?

[chfast]

No, we don't have them.

[jamesthesken]

I can modify the documentation if that's okay with you both @chfast @gumb0 I was hoping I could make a contribution 😄

[chfast]

I can modify the documentation if that's okay with you both @chfast @gumb0 I was hoping I could make a contribution smile

Yes. Please document that:

• C++14 is now required,
• minimal requirements for compilers are:
  • GCC 6,
  • Clang 6,
  • Visual Studio 2017.

[jamesthesken]

@chfast Thanks! I'll start a PR soon