Update to LDC 1.20.0 stable release

[WebDrake]

ldc2.conf has been updated to bring it in line with the upstream LDC build, adding a separate section for 32-bit config and dropping the now unneeded --no-warn-mismatch.

https://github.com/ldc-developers/ldc/releases/tag/v1.20.0

[WebDrake]

Updates to ldc2.conf are in line with discussion in https://github.com/ldc-developers/ldc2.snap/issues/102.

I'd like to also update to LLVM 10.0.1 but I keep getting build errors for SPIRV-LLVM-Translator:

[2336/3819] Building CXX object projects/SPIRV-LLVM-Translator/lib/SPIRV/CMakeFiles/LLVMSPIRVLib.dir/VectorComputeUtil.cpp.o
FAILED: /usr/bin/c++   -DGTEST_HAS_RTTI=0 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Iprojects/SPIRV-LLVM-Translator/lib/SPIRV -I/root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV -Iinclude -I/root/parts/llvm/src/llvm/include -I/root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/include -I/root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/libSPIRV -I/root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/Mangler -static-libstdc++ -fPIC -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wno-maybe-uninitialized -Wdelete-non-virtual-dtor -Wno-comment -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG    -fno-exceptions -fno-rtti -std=c++14 -MMD -MT projects/SPIRV-LLVM-Translator/lib/SPIRV/CMakeFiles/LLVMSPIRVLib.dir/VectorComputeUtil.cpp.o -MF projects/SPIRV-LLVM-Translator/lib/SPIRV/CMakeFiles/LLVMSPIRVLib.dir/VectorComputeUtil.cpp.o.d -o projects/SPIRV-LLVM-Translator/lib/SPIRV/CMakeFiles/LLVMSPIRVLib.dir/VectorComputeUtil.cpp.o -c /root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/VectorComputeUtil.cpp
/root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/VectorComputeUtil.cpp:68:69: error: specialization of 'template<class Ty1, class Ty2, class Identifier> void SPIRV::SPIRVMap<Ty1, Ty2, Identifier>::init()' in different namespace [-fpermissive]
 template <> inline void SPIRVMap<VCRoundMode, VCFloatControl>::init() {
                                                                     ^
In file included from /root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/libSPIRV/SPIRVOpCode.h:43:0,
                 from /root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/libSPIRV/SPIRVEnum.h:44,
                 from /root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/SPIRVInternal.h:43,
                 from /root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/VectorComputeUtil.h:43,
                 from /root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/VectorComputeUtil.cpp:39:
/root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/libSPIRV/SPIRVUtil.h:84:8: error:   from definition of 'template<class Ty1, class Ty2, class Identifier> void SPIRV::SPIRVMap<Ty1, Ty2, Identifier>::init()' [-fpermissive]
   void init();
        ^
/root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/VectorComputeUtil.cpp:74:69: error: specialization of 'template<class Ty1, class Ty2, class Identifier> void SPIRV::SPIRVMap<Ty1, Ty2, Identifier>::init()' in different namespace [-fpermissive]
 template <> inline void SPIRVMap<VCFloatMode, VCFloatControl>::init() {
                                                                     ^
In file included from /root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/libSPIRV/SPIRVOpCode.h:43:0,
                 from /root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/libSPIRV/SPIRVEnum.h:44,
                 from /root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/SPIRVInternal.h:43,
                 from /root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/VectorComputeUtil.h:43,
                 from /root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/VectorComputeUtil.cpp:39:
/root/parts/llvm/src/llvm/projects/SPIRV-LLVM-Translator/lib/SPIRV/libSPIRV/SPIRVUtil.h:84:8: error:   from definition of 'template<class Ty1, class Ty2, class Identifier> void SPIRV::SPIRVMap<Ty1, Ty2, Identifier>::init()' [-fpermissive]
   void init();
        ^

Can anyone advise what the problem is? It's not obvious from the current LLVM Azure Pipelines setup.

[JohanEngelen]

@thewilsonator Do you know if building SPIRV is broken in LLVM 10.0.1?

[kinke]

There haven't been any issues wrt. SPIRV for 10.0.1. Are you sure you haven't just forgotten a git submodule update?

[kinke]

Btw 1.20.0 was bad, there's 1.20.1.

[WebDrake]

The submodule update should happen automatically when the code is first checked out (I'll verify, though). Are there any differences in terms of build setup, compiler to use, etc. that might make a difference?

[kinke]

Btw, LLVM 10 for < 1.21 final isn't recommended because of https://github.com/ldc-developers/ldc/issues/3397. - There might have been some host compiler bumps (even a jump from C++11 to 14), but I don't remember exactly (edit: assuming you're trying to upgrade from v9) - compare the Azure scripts if in doubt. The Shippable host compiler hasn't been updated in ages though (g++ 8).

[WebDrake]

OK, I'll save LLVM 10 for the 1.21 release then. The C(++) compiler might be an issue though: the setup is probably installing g++ 5.4.0.

How is the LLVM CI installing g++ 8? I just see a regular apt-get install g++ so I don't follow why it would be g++ 8, given that the VM image is ubuntu-16.04 and the default g++ in 16.04 is 5.4.0

[WebDrake]

Updated the patch to use LDC 1.20.1.

[kinke]

Wrt. LLVM and future snaps, note that I've switched to another repo with v9.0.1, and that monorepo required some changes. These changes shouldn't affect anyone using the custom src tarball though (instead of git), so I recommend simply using that one.

Wrt. g++ 8, that's for Shippable (the AArch64 CI service) and is simply due to their custom image. For Windows and Linux x86, I use clang (v10 now for 10.0.1, was v9 for 10.0.0).

[WebDrake]

Yes, I'm already using the llvm-project repo. I can try using the src tarball instead though.