1 files changed, 127 insertions, 0 deletions
diff --git a/rod/importer.nim b/rod/importer.nim
new file mode 100755
index 000000000..4b40ea8f8
--- /dev/null
+++ b/rod/importer.nim
@@ -0,0 +1,127 @@
+#
+#
+#           The Nimrod Compiler
+#        (c) Copyright 2008 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+# This module implements the symbol importing mechanism.
+
+import 
+  strutils, os, ast, astalgo, msgs, options, idents, rodread, lookups, semdata, 
+  passes
+
+proc evalImport*(c: PContext, n: PNode): PNode
+proc evalFrom*(c: PContext, n: PNode): PNode
+proc importAllSymbols*(c: PContext, fromMod: PSym)
+proc getModuleFile*(n: PNode): string
+# implementation
+
+proc findModule(info: TLineInfo, modulename: string): string = 
+  # returns path to module
+  result = options.FindFile(AddFileExt(modulename, nimExt))
+  if result == "": liMessage(info, errCannotOpenFile, modulename)
+  
+proc getModuleFile(n: PNode): string = 
+  case n.kind
+  of nkStrLit, nkRStrLit, nkTripleStrLit: 
+    result = findModule(n.info, UnixToNativePath(n.strVal))
+  of nkIdent: 
+    result = findModule(n.info, n.ident.s)
+  of nkSym: 
+    result = findModule(n.info, n.sym.name.s)
+  else: 
+    internalError(n.info, "getModuleFile()")
+    result = ""
+
+proc rawImportSymbol(c: PContext, s: PSym) = 
+  var 
+    check, copy, e: PSym
+    etyp: PType               # enumeration type
+    it: TIdentIter
+  # This does not handle stubs, because otherwise loading on demand would be
+  # pointless in practice. So importing stubs is fine here!
+  copy = s # do not copy symbols when importing!
+  # check if we have already a symbol of the same name:
+  check = StrTableGet(c.tab.stack[importTablePos], s.name)
+  if (check != nil) and (check.id != copy.id): 
+    if not (s.kind in OverloadableSyms): 
+      # s and check need to be qualified:
+      IntSetIncl(c.AmbiguousSymbols, copy.id)
+      IntSetIncl(c.AmbiguousSymbols, check.id)
+  StrTableAdd(c.tab.stack[importTablePos], copy)
+  if s.kind == skType: 
+    etyp = s.typ
+    if etyp.kind in {tyBool, tyEnum}: 
+      for j in countup(0, sonsLen(etyp.n) - 1): 
+        e = etyp.n.sons[j].sym
+        if (e.Kind != skEnumField): 
+          InternalError(s.info, "rawImportSymbol") 
+          # BUGFIX: because of aliases for enums the symbol may already
+          # have been put into the symbol table
+          # BUGFIX: but only iff they are the same symbols!
+        check = InitIdentIter(it, c.tab.stack[importTablePos], e.name)
+        while check != nil: 
+          if check.id == e.id: 
+            e = nil
+            break 
+          check = NextIdentIter(it, c.tab.stack[importTablePos])
+        if e != nil: 
+          rawImportSymbol(c, e)
+  elif s.kind == skConverter: 
+    addConverter(c, s)        # rodgen assures that converters are no stubs
+  
+proc importSymbol(c: PContext, ident: PNode, fromMod: PSym) = 
+  var 
+    s, e: PSym
+    it: TIdentIter
+  if (ident.kind != nkIdent): InternalError(ident.info, "importSymbol")
+  s = StrTableGet(fromMod.tab, ident.ident)
+  if s == nil: liMessage(ident.info, errUndeclaredIdentifier, ident.ident.s)
+  if s.kind == skStub: loadStub(s)
+  if not (s.Kind in ExportableSymKinds): 
+    InternalError(ident.info, "importSymbol: 2")  
+  # for an enumeration we have to add all identifiers
+  case s.Kind
+  of skProc, skMethod, skIterator, skMacro, skTemplate, skConverter: 
+    # for a overloadable syms add all overloaded routines
+    e = InitIdentIter(it, fromMod.tab, s.name)
+    while e != nil: 
+      if (e.name.id != s.Name.id): InternalError(ident.info, "importSymbol: 3")
+      rawImportSymbol(c, e)
+      e = NextIdentIter(it, fromMod.tab)
+  else: rawImportSymbol(c, s)
+  
+proc importAllSymbols(c: PContext, fromMod: PSym) = 
+  var i: TTabIter
+  var s = InitTabIter(i, fromMod.tab)
+  while s != nil: 
+    if s.kind != skModule: 
+      if s.kind != skEnumField: 
+        if not (s.Kind in ExportableSymKinds): 
+          InternalError(s.info, "importAllSymbols: " & $s.kind)
+        rawImportSymbol(c, s) # this is correct!
+    s = NextIter(i, fromMod.tab)
+
+proc evalImport(c: PContext, n: PNode): PNode = 
+  result = n
+  for i in countup(0, sonsLen(n) - 1): 
+    var f = getModuleFile(n.sons[i])
+    var m = gImportModule(f)
+    if sfDeprecated in m.flags: 
+      liMessage(n.sons[i].info, warnDeprecated, m.name.s) 
+    # ``addDecl`` needs to be done before ``importAllSymbols``!
+    addDecl(c, m)             # add symbol to symbol table of module
+    importAllSymbols(c, m)
+
+proc evalFrom(c: PContext, n: PNode): PNode = 
+  result = n
+  checkMinSonsLen(n, 2)
+  var f = getModuleFile(n.sons[0])
+  var m = gImportModule(f)
+  n.sons[0] = newSymNode(m)
+  addDecl(c, m)               # add symbol to symbol table of module
+  for i in countup(1, sonsLen(n) - 1): importSymbol(c, n.sons[i], m)
+