Possible to override the definitions created by nimterop? [low priority feature request]

[kaushalmodi]

Hello,

This feature request is a spin-off off #50.

I was wondering if something like this can be made to work:

import nimterop/cimport

# ...

const
  xlmIncludePath = getEnv("XCELIUM_ROOT") / ".." / "include"
static:
  doAssert fileExists(xlmIncludePath / "svdpi.h")
  doAssert fileExists(xlmIncludePath / "svdpi_compatibility.h")

const
  headersvdpiLocal = xlmIncludePath / "svdpi.h"
type
  svOpenArrayHandle* = pointer
proc svGetArrElemPtr*(a1: svOpenArrayHandle; indx1: cint): pointer {.
    importc: "svGetArrElemPtr", header: headersvdpiLocal.}
proc svGetArrElemPtr1*(a1: svOpenArrayHandle; indx1: cint): pointer {.
    importc: "svGetArrElemPtr1", header: headersvdpiLocal.}
proc svGetArrElemPtr2*(a1: svOpenArrayHandle; indx1: cint; indx2: cint): pointer {.
    importc: "svGetArrElemPtr2", header: headersvdpiLocal.}
proc svGetArrElemPtr3*(a1: svOpenArrayHandle; indx1: cint; indx2: cint; indx3: cint): pointer {.
    importc: "svGetArrElemPtr3", header: headersvdpiLocal.}

cAddSearchDir(xlmIncludePath)
cImport(cSearchPath("svdpi.h"))

The idea is that cImport skips defining svOpenArrayHandle, svGetArrElemPtr, etc. which already got defined before cImport got called.

Without that, right now I get the below expected error:

/home/kmodi/stow/pkgs/nim/devel/lib/core/macros.nim(528, 3) Error: redefinition of 'svOpenArrayHandle'; previous declaration here: ../../svdpi.nim(22, 3)

So nimterop needs to check if an identifier is already defined, and proceed adding its definition only if that identifier doesn't already exist. Is that possible?

[genotrance]

There's no way to find out what's declared already to tell toast to skip those identifiers. But it may be possible to get the AST of the generated code and skip adding things that are already system.defined().

Needs some AST magic but just might be possible. Worthwhile cause nimterop fixes may introduce a symbol that was previous skipped, breaking a wrapper author's workarounds.