Fatal Error building the llvm source code in Ubunt

I am trying to build LLVM source code on Ubuntu 16.04. I have tried versions 4.0.1, 4.0.0 and 3.9.0 with sources from here. I have also tried using the source from svn as shown in several tutorials.

Here is the error I get :

[1480/1747] Linking CXX executable bin/clang-3.9
FAILED: : && /usr/bin/c++   -fPIC -fvisibility-inlines-hidden -Wall -W -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wno-maybe-uninitialized -Wdelete-non-virtual-dtor -Wno-comment -Werror=date-time -std=c++11 -fno-common -Woverloaded-virtual -fno-strict-aliasing -g  -Wl,-allow-shlib-undefined   -Wl,--export-dynamic tools/clang/tools/driver/CMakeFiles/clang.dir/driver.cpp.o tools/clang/tools/driver/CMakeFiles/clang.dir/cc1_main.cpp.o tools/clang/tools/driver/CMakeFiles/clang.dir/cc1as_main.cpp.o  -o bin/clang-3.9  lib/libLLVMAArch64CodeGen.a lib/libLLVMAArch64AsmPrinter.a lib/libLLVMAArch64AsmParser.a lib/libLLVMAArch64Desc.a lib/libLLVMAArch64Info.a lib/libLLVMAArch64Disassembler.a lib/libLLVMAMDGPUCodeGen.a lib/libLLVMAMDGPUAsmPrinter.a lib/libLLVMAMDGPUAsmParser.a lib/libLLVMAMDGPUDesc.a lib/libLLVMAMDGPUInfo.a lib/libLLVMAMDGPUDisassembler.a lib/libLLVMARMCodeGen.a lib/libLLVMARMAsmPrinter.a lib/libLLVMARMAsmParser.a lib/libLLVMARMDesc.a lib/libLLVMARMInfo.a lib/libLLVMARMDisassembler.a lib/libLLVMBPFCodeGen.a lib/libLLVMBPFAsmPrinter.a lib/libLLVMBPFDesc.a lib/libLLVMBPFInfo.a lib/libLLVMHexagonCodeGen.a lib/libLLVMHexagonAsmParser.a lib/libLLVMHexagonDesc.a lib/libLLVMHexagonInfo.a lib/libLLVMHexagonDisassembler.a lib/libLLVMMipsCodeGen.a lib/libLLVMMipsAsmPrinter.a lib/libLLVMMipsAsmParser.a lib/libLLVMMipsDesc.a lib/libLLVMMipsInfo.a lib/libLLVMMipsDisassembler.a lib/libLLVMMSP430CodeGen.a lib/libLLVMMSP430AsmPrinter.a lib/libLLVMMSP430Desc.a lib/libLLVMMSP430Info.a lib/libLLVMNVPTXCodeGen.a lib/libLLVMNVPTXAsmPrinter.a lib/libLLVMNVPTXDesc.a lib/libLLVMNVPTXInfo.a lib/libLLVMPowerPCCodeGen.a lib/libLLVMPowerPCAsmPrinter.a lib/libLLVMPowerPCAsmParser.a lib/libLLVMPowerPCDesc.a lib/libLLVMPowerPCInfo.a lib/libLLVMPowerPCDisassembler.a lib/libLLVMSparcCodeGen.a lib/libLLVMSparcAsmPrinter.a lib/libLLVMSparcAsmParser.a lib/libLLVMSparcDesc.a lib/libLLVMSparcInfo.a lib/libLLVMSparcDisassembler.a lib/libLLVMSystemZCodeGen.a lib/libLLVMSystemZAsmPrinter.a lib/libLLVMSystemZAsmParser.a lib/libLLVMSystemZDesc.a lib/libLLVMSystemZInfo.a lib/libLLVMSystemZDisassembler.a lib/libLLVMX86CodeGen.a lib/libLLVMX86AsmPrinter.a lib/libLLVMX86AsmParser.a lib/libLLVMX86Desc.a lib/libLLVMX86Info.a lib/libLLVMX86Disassembler.a lib/libLLVMXCoreCodeGen.a lib/libLLVMXCoreAsmPrinter.a lib/libLLVMXCoreDesc.a lib/libLLVMXCoreInfo.a lib/libLLVMXCoreDisassembler.a lib/libLLVMAnalysis.a lib/libLLVMCodeGen.a lib/libLLVMCore.a lib/libLLVMipo.a lib/libLLVMInstCombine.a lib/libLLVMInstrumentation.a lib/libLLVMMC.a lib/libLLVMMCParser.a lib/libLLVMObjCARCOpts.a lib/libLLVMOption.a lib/libLLVMScalarOpts.a lib/libLLVMSupport.a lib/libLLVMTransformUtils.a lib/libLLVMVectorize.a -lpthread lib/libclangBasic.a lib/libclangCodeGen.a lib/libclangDriver.a lib/libclangFrontend.a lib/libclangFrontendTool.a lib/libPolly.a lib/libLLVMGlobalISel.a lib/libLLVMAArch64Desc.a lib/libLLVMAArch64AsmPrinter.a lib/libLLVMAArch64Info.a lib/libLLVMAArch64Utils.a lib/libLLVMAMDGPUDesc.a lib/libLLVMAMDGPUAsmPrinter.a lib/libLLVMAMDGPUInfo.a lib/libLLVMAMDGPUUtils.a lib/libLLVMARMDesc.a lib/libLLVMARMAsmPrinter.a lib/libLLVMARMInfo.a lib/libLLVMBPFAsmPrinter.a lib/libLLVMHexagonDesc.a lib/libLLVMHexagonInfo.a lib/libLLVMMipsAsmPrinter.a lib/libLLVMMipsInfo.a lib/libLLVMMSP430AsmPrinter.a lib/libLLVMNVPTXAsmPrinter.a lib/libLLVMPowerPCAsmPrinter.a lib/libLLVMPowerPCInfo.a lib/libLLVMSparcAsmPrinter.a lib/libLLVMSparcInfo.a lib/libLLVMSystemZDesc.a lib/libLLVMSystemZAsmPrinter.a lib/libLLVMSystemZInfo.a lib/libLLVMX86AsmPrinter.a lib/libLLVMX86Utils.a lib/libLLVMX86Info.a lib/libLLVMXCoreAsmPrinter.a lib/libLLVMAsmPrinter.a lib/libLLVMDebugInfoCodeView.a lib/libLLVMSelectionDAG.a lib/libLLVMCodeGen.a lib/libLLVMXCoreInfo.a lib/libLLVMMCDisassembler.a lib/libclangCodeGen.a lib/libLLVMipo.a lib/libLLVMVectorize.a lib/libLLVMInstrumentation.a lib/libLLVMObjCARCOpts.a lib/libLLVMScalarOpts.a lib/libLLVMInstCombine.a lib/libLLVMTarget.a lib/libLLVMBitWriter.a lib/libLLVMIRReader.a lib/libLLVMAsmParser.a lib/libLLVMLinker.a lib/libLLVMTransformUtils.a lib/libLLVMAnalysis.a lib/libLLVMCoverage.a lib/libLLVMObject.a lib/libclangRewriteFrontend.a lib/libclangARCMigrate.a lib/libclangStaticAnalyzerFrontend.a lib/libclangFrontend.a lib/libclangDriver.a lib/libLLVMOption.a lib/libLLVMProfileData.a lib/libclangParse.a lib/libLLVMMCParser.a lib/libclangSerialization.a lib/libLLVMBitReader.a lib/libclangSema.a lib/libclangEdit.a lib/libclangStaticAnalyzerCheckers.a lib/libclangStaticAnalyzerCore.a lib/libclangAnalysis.a lib/libclangAST.a lib/libclangRewrite.a lib/libclangLex.a lib/libclangBasic.a lib/libLLVMCore.a lib/libLLVMMC.a lib/libLLVMSupport.a -lrt -ldl -ltinfo -lpthread -lz -lm lib/libPollyISL.a -Wl,-rpath,"\$ORIGIN/../lib" && :
collect2: fatal error: ld terminated with signal 9 [Killed]

This is a recurring error in all three versions I tried, so there's probably some step I am missing or some other problem too.

These are my steps:

Download llvm.
Download clang, lld and polly and put in llvm/tools.
Download compiler-rt, openmp, libcxx, libcxxabi and test-suite and put in llvm/projects
Run cmake -G Ninja -DLLVM_ENABLE_ASSERTIONS=On ..
Run ninja -j4

I don't know how to remove this error and dont have any experience with LLVM. Please explain the reason for the error too.

This may be caused by the linking step using too much memory. On my system there was enough swap space enabled which made the system practically unusable. Otherwise the Linux kernel will kill some processes according to a heuristic that probably involves going after the biggest memory user, which could explain your problem (ld is killed).

If you have something around 8 GB of RAM it may be possible to finish with at most one link job in parallel. By default llvm is built with static libraries which causes the linking to take excessive amounts of memory (AFAIR due to debug info). Then usually several large executables will be linked in parallel by ninja and your system will run out of memory.

Try to add -DLLVM_PARALLEL_LINK_JOBS=1 to your cmake invocation.

There is also an option to build shared libraries which should alleviate this problem, I think it is -DLLVM_LINK_LLVM_DYLIB=true.

For more info on CMake options see: http://llvm.org/docs/CMake.html

I think that using the gold linker also helps because it is somewhat more efficient than the default linker. It is enabled by passing -DLLVM_USE_LINKER=gold to cmake.

Finally, the release build does not contain the debug info, which takes up a lot of the memory, so it should take less memory to build.

Update: I recently came across this article, that describes how to use split dwarf to speed up compiles with LLVM as an example. This helps the memory consumption of the linker by separating the debug information from the object files being linked. For LLVM split dwarf is enabled by passing the option -DLLVM_USE_SPLIT_DWARF=ON to cmake.