[llgo] clear data layout before adding module to JIT

[axw]

Summary

r242414 made the ExecutionEngine the owner of the data
layout, which broke llgoi (runtime assertion in
MCJIT::generateCodeForModule due to data layout mismatch).
Before adding modules to the engine, clear the data layout
so it will be set by the engine.

[mehdi_amini]

cmd/llgoi/llgoi.go

155

There i something fishy, why is the datalayout set to something else than the target in the first place?

[axw]

cmd/llgoi/llgoi.go

155

http://llvm.org/klaus/llgo/blob/master/irgen/targets.go#L-43

I don't recall how that came to be, but most likely that needs to be fixed. I'll close this and look into that, thanks.

cmd/llgoi/llgoi.go

func (in *interp) loadSourcePackage(fset *token.FileSet, files []*ast.File, pkgpath string, copts irgen.CompilerOptions) (pkg *types.Package, err error) {
   }
 
   module, err := compiler.Compile(fset, files, pkgpath)
   if err != nil {
     return
   }
   pkg = module.Package
 
+  // Clear the data layout; the JIT wants to set it.
+  module.Module.SetDataLayout("")
+
   if in.engine.C != nil {
     in.engine.AddModule(module.Module)
   } else {
     options := llvm.NewMCJITCompilerOptions()
     in.engine, err = llvm.NewMCJITCompiler(module.Module, options)
     if err != nil {
       return
     }