llvm-d problem

app.d

import std.stdio, std.conv;
import llvm.all;

void main()
{ 
    if(!LLVM.loaded)
        LLVM.loadFromPath("lib");
    char* error = null;
    LLVMModuleRef mod = LLVMModuleCreateWithName("fac_module");
    LLVMTypeRef[] fac_args = [LLVMInt32Type()];
    LLVMValueRef fac = LLVMAddFunction(mod, "fac", LLVMFunctionType(LLVMInt32Type(), fac_args.ptr, 1, 0));
    LLVMSetFunctionCallConv(fac, LLVMCCallConv);
    LLVMValueRef n = LLVMGetParam(fac, 0);

    LLVMBasicBlockRef entry = LLVMAppendBasicBlock(fac, "entry");
    LLVMBasicBlockRef iftrue = LLVMAppendBasicBlock(fac, "iftrue");
    LLVMBasicBlockRef iffalse = LLVMAppendBasicBlock(fac, "iffalse");
    LLVMBasicBlockRef end = LLVMAppendBasicBlock(fac, "end");
    LLVMBuilderRef builder = LLVMCreateBuilder();

    LLVMPositionBuilderAtEnd(builder, entry);
    LLVMValueRef If = LLVMBuildICmp(builder, LLVMIntEQ, n, LLVMConstInt(LLVMInt32Type(), 0, 0), "n == 0");
    LLVMBuildCondBr(builder, If, iftrue, iffalse);

    LLVMPositionBuilderAtEnd(builder, iftrue);
    LLVMValueRef res_iftrue = LLVMConstInt(LLVMInt32Type(), 1, 0);
    LLVMBuildBr(builder, end);

    LLVMPositionBuilderAtEnd(builder, iffalse);
    LLVMValueRef n_minus = LLVMBuildSub(builder, n, LLVMConstInt(LLVMInt32Type(), 1, 0), "n - 1");
    LLVMValueRef[] call_fac_args = [n_minus];
    LLVMValueRef call_fac = LLVMBuildCall(builder, fac, call_fac_args.ptr, 1, "fac(n - 1)");
    LLVMValueRef res_iffalse = LLVMBuildMul(builder, n, call_fac, "n * fac(n - 1)");
    LLVMBuildBr(builder, end);

    LLVMPositionBuilderAtEnd(builder, end);
    LLVMValueRef res = LLVMBuildPhi(builder, LLVMInt32Type(), "result");
    LLVMValueRef[] phi_vals = [res_iftrue, res_iffalse];
    LLVMBasicBlockRef[] phi_blocks = [iftrue, iffalse];
    LLVMAddIncoming(res, phi_vals.ptr, phi_blocks.ptr, 2);
    LLVMBuildRet(builder, res);

    LLVMVerifyModule(mod, LLVMAbortProcessAction, &error);
    LLVMDisposeMessage(error); // Handler == LLVMAbortProcessAction -> No need to check errors


    LLVMExecutionEngineRef engine;
    error = null;
    //LLVMCreateJITCompiler(&engine, provider, 0, &error); // doesn't work yet...
    LLVMCreateExecutionEngineForModule(&engine, mod, &error);
    if(error) {
        stderr.writeln(to!string(error));
        LLVMDisposeMessage(error);  
        throw new Exception(to!string(error));
    }

    LLVMPassManagerRef pass = LLVMCreatePassManager();
    LLVMAddTargetData(LLVMGetExecutionEngineTargetData(engine), pass);
    LLVMAddConstantPropagationPass(pass);
    LLVMAddInstructionCombiningPass(pass);
    LLVMAddPromoteMemoryToRegisterPass(pass);
    // LLVMAddDemoteMemoryToRegisterPass(pass); // Demotes every possible value to memory
    LLVMAddGVNPass(pass);
    LLVMAddCFGSimplificationPass(pass);
    LLVMRunPassManager(pass, mod);
    LLVMDumpModule(mod);

    LLVMGenericValueRef[] exec_args = [LLVMCreateGenericValueOfInt(LLVMInt32Type(), 18, 0)];
    LLVMGenericValueRef exec_res = LLVMRunFunction(engine, fac, 1, exec_args.ptr);
    stderr.writeln("\n; Running fac...");
    stderr.writeln("; Result: ", LLVMGenericValueToInt(exec_res, 0));

    LLVMDisposePassManager(pass);
    LLVMDisposeBuilder(builder);
    LLVMDisposeExecutionEngine(engine);
}

error1

Building configuration "application", build type debug
Running dmd (compile)...
.dub/packages/llvm-d/llvm/d/ir/type.d(86): Warning: statement is not reachable
.dub/packages/llvm-d/llvm/d/ir/type.d(346): Warning: statement is not reachable
Error: Build command failed with exit code 1

Run 'dub help' for usage information.

error2

Building configuration "application", build type $DFLAGS
Running dmd (compile)...
.dub/packages/llvm-d/llvm/d/ir/type.d(86): Warning: statement is not reachable
.dub/packages/llvm-d/llvm/d/ir/type.d(346): Warning: statement is not reachable
Linking...
temp.o: In function `_D4llvm4util5shlib9SharedLib8loadFileMFAyaZb':
.dub/packages/llvm-d/llvm/c/constants.d:(.text._D4llvm4util5shlib9SharedLib8loadFileMFAyaZb+0x36): undefined reference to `dlopen'
.dub/packages/llvm-d/llvm/c/constants.d:(.text._D4llvm4util5shlib9SharedLib8loadFileMFAyaZb+0x4d): undefined reference to `dlerror'
temp.o: In function `_D4llvm4util5shlib9SharedLib6unloadMFZv':
.dub/packages/llvm-d/llvm/c/constants.d:(.text._D4llvm4util5shlib9SharedLib6unloadMFZv+0x60): undefined reference to `dlclose'
temp.o: In function `_D4llvm4util5shlib9SharedLib60__T10loadSymbolTPUNbPS4llvm1c5types16LLVMOpaqueModulekPPaZiZ10loadSymbolMFAyaZPUNbPS4llvm1c5types16LLVMOpaqueModulekPPaZi':
.dub/packages/llvm-d/llvm/c/constants.d:(.text._D4llvm4util5shlib9SharedLib60__T10loadSymbolTPUNbPS4llvm1c5types16LLVMOpaqueModulekPPaZiZ10loadSymbolMFAyaZPUNbPS4llvm1c5types16LLVMOpaqueModulekPPaZi+0x70): undefined reference to `dlsym'
temp.o: In function `_D4llvm4util5shlib9SharedLib56__T10loadSymbolTPUNbPS4llvm1c5types15LLVMOpaqueValuekZiZ10loadSymbolMFAyaZPUNbPS4llvm1c5types15LLVMOpaqueValuekZi':
.dub/packages/llvm-d/llvm/c/constants.d:(.text._D4llvm4util5shlib9SharedLib56__T10loadSymbolTPUNbPS4llvm1c5types15LLVMOpaqueValuekZiZ10loadSymbolMFAyaZPUNbPS4llvm1c5types15LLVMOpaqueValuekZi+0x70): undefined reference to `dlsym'
temp.o: In function `_D4llvm4util5shlib9SharedLib55__T10loadSymbolTPUNbPS4llvm1c5types15LLVMOpaqueValueZvZ10loadSymbolMFAyaZPUNbPS4llvm1c5types15LLVMOpaqueValueZv':
.dub/packages/llvm-d/llvm/c/constants.d:(.text._D4llvm4util5shlib9SharedLib55__T10loadSymbolTPUNbPS4llvm1c5types15LLVMOpaqueValueZvZ10loadSymbolMFAyaZPUNbPS4llvm1c5types15LLVMOpaqueValueZv+0x70): undefined reference to `dlsym'
temp.o: In function `_D4llvm4util5shlib9SharedLib99__T10loadSymbolTPUNbPS4llvm1c5types22LLVMOpaqueMemoryBufferPPS4llvm1c5types16LLVMOpaqueModulePPaZiZ10loadSymbolMFAyaZPUNbPS4llvm1c5types22LLVMOpaqueMemoryBufferPPS4llvm1c5types16LLVMOpaqueModulePPaZi':
.dub/packages/llvm-d/llvm/c/constants.d:(.text._D4llvm4util5shlib9SharedLib99__T10loadSymbolTPUNbPS4llvm1c5types22LLVMOpaqueMemoryBufferPPS4llvm1c5types16LLVMOpaqueModulePPaZiZ10loadSymbolMFAyaZPUNbPS4llvm1c5types22LLVMOpaqueMemoryBufferPPS4llvm1c5types16LLVMOpaqueModulePPaZi+0x70): undefined reference to `dlsym'
temp.o: In function `_D4llvm4util5shlib9SharedLib133__T10loadSymbolTPUNbPS4llvm1c5types17LLVMOpaqueContextPS4llvm1c5types22LLVMOpaqueMemoryBufferPPS4llvm1c5types16LLVMOpaqueModulePPaZiZ10loadSymbolMFAyaZPUNbPS4llvm1c5types17LLVMOpaqueContextPS4llvm1c5types22LLVMOpaqueMemoryBufferPPS4llvm1c5types16LLVMOpaqueModulePPaZi':
.dub/packages/llvm-d/llvm/c/constants.d:(.text._D4llvm4util5shlib9SharedLib133__T10loadSymbolTPUNbPS4llvm1c5types17LLVMOpaqueContextPS4llvm1c5types22LLVMOpaqueMemoryBufferPPS4llvm1c5types16LLVMOpaqueModulePPaZiZ10loadSymbolMFAyaZPUNbPS4llvm1c5types17LLVMOpaqueContextPS4llvm1c5types22LLVMOpaqueMemoryBufferPPS4llvm1c5types16LLVMOpaqueModulePPaZi+0x70): undefined reference to `dlsym'
temp.o:.dub/packages/llvm-d/llvm/c/constants.d:(.text._D4llvm4util5shlib9SharedLib141__T10loadSymbolTPUNbPS4llvm1c5types17LLVMOpaqueContextPS4llvm1c5types22LLVMOpaqueMemoryBufferPPS4llvm1c5types24LLVMOpaqueModuleProviderPPaZiZ10loadSymbolMFAyaZPUNbPS4llvm1c5types17LLVMOpaqueContextPS4llvm1c5types22LLVMOpaqueMemoryBufferPPS4llvm1c5types24LLVMOpaqueModuleProviderPPaZi+0x70): more undefined references to `dlsym' follow
collect2: error: ld returned 1 exit status
--- errorlevel 1
Error: Link command failed with exit code 1

Repro Steps

Starting in some directory, run these commands:

$ dub init llvmtest
$ cd llvmtest
$ (some editor) source/app.d

Paste the contents of app.d in from above, save & close

$ (some editor) package.json

Add the "llvm-d": "~master" line in dependencies

$ dub

Resulting error1 above. Dmd is treating warnings as errors... so, to overcome that:

$ export DFLAGS="-wi"
$ dub

Resulting error2 above

$ dub --rdmd

Runs correctly.