implemented new experimental scriptable import mechanism

compiler/gorgeimpl.nim

@@ -0,0 +1,83 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2017 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Module that implements ``gorge`` for the compiler as well as
+## the scriptable import mechanism.
+
+import msgs, securehash, os, osproc, streams, strutils, options
+
+proc readOutput(p: Process): (string, int) =
+  result[0] = ""
+  var output = p.outputStream
+  while not output.atEnd:
+    result[0].add(output.readLine)
+    result[0].add("\n")
+  if result[0].len > 0:
+    result[0].setLen(result[0].len - "\n".len)
+  result[1] = p.waitForExit
+
+proc opGorge*(cmd, input, cache: string, info: TLineInfo): (string, int) =
+  let workingDir = parentDir(info.toFullPath)
+  if cache.len > 0:# and optForceFullMake notin gGlobalOptions:
+    let h = secureHash(cmd & "\t" & input & "\t" & cache)
+    let filename = options.toGeneratedFile("gorge_" & $h, "txt")
+    var f: File
+    if open(f, filename):
+      result = (f.readAll, 0)
+      f.close
+      return
+    var readSuccessful = false
+    try:
+      var p = startProcess(cmd, workingDir,
+                           options={poEvalCommand, poStderrToStdout})
+      if input.len != 0:
+        p.inputStream.write(input)
+        p.inputStream.close()
+      result = p.readOutput
+      readSuccessful = true
+      # only cache successful runs:
+      if result[1] == 0:
+        writeFile(filename, result[0])
+    except IOError, OSError:
+      if not readSuccessful: result = ("", -1)
+  else:
+    try:
+      var p = startProcess(cmd, workingDir,
+                           options={poEvalCommand, poStderrToStdout})
+      if input.len != 0:
+        p.inputStream.write(input)
+        p.inputStream.close()
+      result = p.readOutput
+    except IOError, OSError:
+      result = ("", -1)
+
+proc scriptableImport*(pkg, subdir: string; info: TLineInfo): string =
+  var cmd = getConfigVar("resolver.exe")
+  if cmd.len == 0: cmd = "nimresolve"
+  else: cmd = quoteShell(cmd)
+  cmd.add " --source:"
+  cmd.add quoteShell(info.toFullPath())
+  cmd.add " --stdlib:"
+  cmd.add quoteShell(options.libpath)
+  cmd.add "  --project:"
+  cmd.add quoteShell(gProjectFull)
+  if subdir.len != 0:
+    cmd.add " --subdir:"
+    cmd.add quoteShell(subdir)
+  if options.gNoNimblePath:
+    cmd.add " --nonimblepath"
+  cmd.add ' '
+  cmd.add quoteShell(pkg)
+  let (res, exitCode) = opGorge(cmd, "", cmd, info)
+  if exitCode == 0:
+    result = res.strip()
+  elif res.len > 0:
+    localError(info, res)
+  else:
+    localError(info, "cannot resolve: " & (pkg / subdir))