nim-typeImportC-macro

import macros

macro typedefImportC*(name: untyped, importc: string, header: string, typ: untyped): typed =
  var whenStmt = newNimNode(nnkWhenStmt)
  var useWinSdkBranch = newNimNode(nnkElifBranch)
  var useWinSdkCond = newNimNode(nnkCall)
  useWinSdkCond.add(newIdentNode(!"defined"), newIdentNode(!"useWinSdk"))
  useWinSdkBranch.add()
  var winSdkTypeDef = newNimNode(nnkTypeDef)
  winSdkTypeDef.add(name)
  var winSdkTypePragma = newNimNode(nnkPragma)
  winSdkTypePragma.add(newColonExpr(newIdentNode(!"importC"), importc))
  winSdkTypePragma.add(newColonExpr(newIdentNode(!"header"), header))
  winSdkTypeDef.add(winSdkTypePragma)
  winSdkTypeDef.add(typ)
  useWinSdkBranch.add(winSdkTypePragma)
  whenStmt.add(useWinSdkBranch)
  var elseBranch = newNimNode(nnkElse)
  var elseTypeDef = newNimNode(nnkTypeDef)
  elseTypeDef.add(name, newEmptyNode(), typ)
  elseBranch.add(elseTypeDef)
  whenStmt.add(elseBranch)
  result = whenStmt

when isMainModule:
  typedefImportC(NimType, "ImportedType", "header.h", int32)
  var x: NimType
  x = 42