[Codegen] fix bug on LLVM 10.0

[qingyunqu]

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Fix llvm::CGFT_xxx to llvm::TargetMachine::CGFT_xxx.

[qingyunqu]

@yzhliu

[tqchen]

Thanks @qingyunqu !

[masahi]

@qingyunqu this breaks the build with the trunk as pointed out in #4386. Can you revert this change and instead fix version ifdef? Sorry I didnt test in llvm 10.0.

[qingyunqu]

@masahi Could I push a new version that reduce the second and the third ifdef into one?

[masahi]

No, second elif should be TVM_LLVM_VERSION <= 100. The last one is for the latest llvm.

[masahi]

@qingyunqu where did your get your llvm 10.0? It is not released yet. Maybe you are using out of date trunk?

[qingyunqu]

@masahi Maybe I used the master branch of LLVM

[masahi]

Ok, that means you are using an out of date LLVM trunk. As I mentioned in #4386, LLVM recently introduced changes that break the build of TVM with the LLVM trunk. #4386 fixed that issue, but you reverted that fix in this PR.

Please send another PR that reverts this change. If you update and rebuild your LLVM, the build should succeed.

[qingyunqu]

@masahi Thanks, I will send the PR immediately.

[qingyunqu]

@masahi I have used svn to update my LLVM. But after rebuilding LLVM, the build of tvm without TargetMachine:: also failed. May I make a mistake or misunderstand?

[masahi]

A couple of points:

• LLVM project moved to github https://github.com/llvm/llvm-project. You might want to switch to this repo from svn.
• Make sure you have the enum CodeGenFileType in include/llvm/Support/Codegen.h (not in TargetMachine.h). This shows that CGFT_ObjectFile etc lives under the name space llvm, not llvm::TargetMachine
• Make sure you are building TVM with the correct LLVM installation.

[qingyunqu]

Thanks, I have got the latest LLVM of 10.0.0git version and found the enum CodeGenFileType. I will test the compilation on this version and then push another PR. Thanks a lot!

[qingyunqu]

@masahi I have compiled tvm with 10.0.0git LLVM. There is something wrong when I run cmake:

Then I comment the error line in FindLLVM.cmake:43. Everything becomes ok:

Maybe there is better method to fix this?

[masahi]

I also remember seeing that error (but I don't remember how I fixed it). Unless you have a good solution for this, we can fix that later. If you've confirmed that you can build TVM with the LLVM trunk, please send a PR that reverts this change.