[llvm-dev] build llvm fails under win7 x64/VS2017

[Dennis Luehring via llvm-dev]

my build environment:

Win7 x64
VStudio 2017 Community Edition 15.8.4 (latest)
CMake 3.12.1 (x86)
git 2.19.0 (latest, x64)
Python 2.7.2 (x86)

my build steps:

open VS2017 x64 developer command prompt
cd D:\projects\fun\jit_tests
mkdir llvm
cd llvm
git clone https://github.com/llvm-mirror/llvm
mkdir llvm-build
cd llvm-build
cmake -G "Visual Studio 15 2017 Win64" -DBUILD_SHARED_LIBS=ON 
-DLLVM_TARGETS_TO_BUILD=host -DLLVM_ENABLE_WARNINGS=OFF 
-DLLVM_INCLUDE_EXAMPLES=OFF -DLLVM_INCLUDE_TESTS=OFF 
-DLLVM_INCLUDE_DOCS=OFF ../llvm
cmake --build .

produces these errors and warnings while building

CMake Warning at CMakeLists.txt:29 (message):
   Visual Studio generators use the x86 host compiler by default, even for
   64-bit targets.  This can result in linker instability and out of memory
   errors.  To use the 64-bit host compiler, pass -Thost=x64 on the CMake
   command line.
...
CMake Warning (dev) at utils/benchmark/CMakeLists.txt:3 (project):
   Policy CMP0048 is not set: project() command manages VERSION variables.
   Run "cmake --help-policy CMP0048" for policy details.  Use the 
cmake_policy
   command to set the policy and suppress this warning.
-----> seems related to https://bugs.llvm.org/show_bug.cgi?id=38874
...
CMake Warning at utils/benchmark/CMakeLists.txt:234 (message):
   Using std::regex with exceptions disabled is not fully supported

and later some linker errors

LINK : fatal error LNK1104: cannot open file 
'..\..\Debug\lib\LLVMDemangle.lib' 
[D:\projects\fun\jit_tests\llvm40\llvm40-build\lib\Support\LLVMSupport.vcxproj]
...
LINK : fatal error LNK1104: cannot open file 
'..\..\..\lib\Debug\benchmark.lib' 
[D:\projects\fun\jit_tests\llvm40\llvm40-build\utils\benchmark\src\benchmark_main.vcxproj]
...
LINK : fatal error LNK1104: cannot open file 
'..\..\Debug\lib\LLVMDemangle.lib' 
[D:\projects\fun\jit_tests\llvm40\llvm40-build\lib\Support\LLVMSupport.vcxproj]
...
LINK : fatal error LNK1104: cannot open file 
'..\..\..\lib\Debug\benchmark.lib' 
[D:\projects\fun\jit_tests\llvm40\llvm40-build\utils\benchmark\src\benchmark_main.vcxproj]

i also tried to build LLVM 4 and 6 on a clean cloned version
git checkout -b release_40
git checkout -b release_60

producing the very same warnings/errors and the build breaks

in the end i've got 1 lib and 2 dlls - not what i've expected :)


any ideas?