Import Table - Githubissues

Related to work for #163

In a pretty standard (from what i can tell) wasm generated with emscripten it has the following imports

  (import "env" "memory" (memory (;0;) 256 256))
  (import "env" "table" (table (;0;) 14 14 funcref))
  ;;with table def further down the file
  (elem (;0;) (global.get 1) 50 22 51 51 28 51 23 51 51 51 52 52 52 24) ;;global 1 is just the mem base

and has no memory/table statement for the root module

This results in

The Root Module is decoded correctly
The Root Module has no Memory Sections or Table Sections

the LinearMemory space gets instantiated automatically https://github.com/go-interpreter/wagon/blob/3fd36533bb90cbfea01da645a92b1a7e828ea336/wasm/module.go#L140

while the TableIndexSpace does not (as there is no Table Section) https://github.com/go-interpreter/wagon/blob/3fd36533bb90cbfea01da645a92b1a7e828ea336/wasm/module.go#L141-L143

Which causes a fault when importing the "env" modules table definition (line 213) as module.TableIndexSpace is undefnied https://github.com/go-interpreter/wagon/blob/3fd36533bb90cbfea01da645a92b1a7e828ea336/wasm/imports.go#L209-L214

I can't seem to find much info on if this is per MVP spec or if its a hack for emscripten but should a root module instantiate its own table/memory when an imported module has these entries? Or am I missing something. I've played with various hacks..like inserting

 //while resolving imports wasm/imports.go 209
case ExternalTable:
    if int(index) >= len(importedModule.TableIndexSpace) {
        return InvalidTableIndexError(index)
    }
    //Inserted to setup module.Table if not already setup since import requires it
    if module.Table==nil{
        module.Table=importedModule.Table
        moudile.TableIndexSpace=importedModule.TableIndexSpace
    }
    //end insert
    module.TableIndexSpace[0] = importedModule.TableIndexSpace[0]
    module.imports.Tables++

which seems to give me the correct functionality.

If I'm on the right path I can prep a PR...if I'm way off base I can accept that also (:

Looking for insight. Thanks!

go-interpreter / wagon

Import Table #170