1 files changed, 240 insertions, 0 deletions
diff --git a/rod/lookups.nim b/rod/lookups.nim
new file mode 100755
index 000000000..be4172c86
--- /dev/null
+++ b/rod/lookups.nim
@@ -0,0 +1,240 @@
+#
+#
+#           The Nimrod Compiler
+#        (c) Copyright 2009 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+# This module implements lookup helpers.
+
+import 
+  ast, astalgo, idents, semdata, types, msgs, options, rodread, rnimsyn
+
+type 
+  TOverloadIterMode* = enum 
+    oimDone, oimNoQualifier, oimSelfModule, oimOtherModule, oimSymChoice
+  TOverloadIter*{.final.} = object 
+    stackPtr*: int
+    it*: TIdentIter
+    m*: PSym
+    mode*: TOverloadIterMode
+
+
+proc getSymRepr*(s: PSym): string
+proc CloseScope*(tab: var TSymTab)
+proc AddSym*(t: var TStrTable, n: PSym)
+proc addDecl*(c: PContext, sym: PSym)
+proc addDeclAt*(c: PContext, sym: PSym, at: Natural)
+proc addOverloadableSymAt*(c: PContext, fn: PSym, at: Natural)
+proc addInterfaceDecl*(c: PContext, sym: PSym)
+proc addInterfaceOverloadableSymAt*(c: PContext, sym: PSym, at: int)
+proc lookUp*(c: PContext, n: PNode): PSym
+  # Looks up a symbol. Generates an error in case of nil.
+proc QualifiedLookUp*(c: PContext, n: PNode, ambiguousCheck: bool): PSym
+proc InitOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym
+proc nextOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym
+# implementation
+
+proc getSymRepr(s: PSym): string = 
+  case s.kind
+  of skProc, skMethod, skConverter, skIterator: result = getProcHeader(s)
+  else: result = s.name.s
+  
+proc CloseScope(tab: var TSymTab) = 
+  var 
+    it: TTabIter
+    s: PSym
+  # check if all symbols have been used and defined:
+  if (tab.tos > len(tab.stack)): InternalError("CloseScope")
+  s = InitTabIter(it, tab.stack[tab.tos - 1])
+  while s != nil: 
+    if sfForward in s.flags: 
+      liMessage(s.info, errImplOfXexpected, getSymRepr(s))
+    elif ({sfUsed, sfInInterface} * s.flags == {}) and
+        (optHints in s.options): # BUGFIX: check options in s!
+      if not (s.kind in {skForVar, skParam, skMethod, skUnknown}): 
+        liMessage(s.info, hintXDeclaredButNotUsed, getSymRepr(s))
+    s = NextIter(it, tab.stack[tab.tos - 1])
+  astalgo.rawCloseScope(tab)
+
+proc AddSym(t: var TStrTable, n: PSym) = 
+  if StrTableIncl(t, n): liMessage(n.info, errAttemptToRedefine, n.name.s)
+  
+proc addDecl(c: PContext, sym: PSym) = 
+  if SymTabAddUnique(c.tab, sym) == Failure: 
+    liMessage(sym.info, errAttemptToRedefine, sym.Name.s)
+  
+proc addDeclAt(c: PContext, sym: PSym, at: Natural) = 
+  if SymTabAddUniqueAt(c.tab, sym, at) == Failure: 
+    liMessage(sym.info, errAttemptToRedefine, sym.Name.s)
+  
+proc addOverloadableSymAt(c: PContext, fn: PSym, at: Natural) = 
+  var check: PSym
+  if not (fn.kind in OverloadableSyms): 
+    InternalError(fn.info, "addOverloadableSymAt")
+  check = StrTableGet(c.tab.stack[at], fn.name)
+  if (check != nil) and not (check.Kind in OverloadableSyms): 
+    liMessage(fn.info, errAttemptToRedefine, fn.Name.s)
+  SymTabAddAt(c.tab, fn, at)
+
+proc AddInterfaceDeclAux(c: PContext, sym: PSym) = 
+  if (sfInInterface in sym.flags): 
+    # add to interface:
+    if c.module == nil: InternalError(sym.info, "AddInterfaceDeclAux")
+    StrTableAdd(c.module.tab, sym)
+  if getCurrOwner().kind == skModule: incl(sym.flags, sfGlobal)
+  
+proc addInterfaceDecl(c: PContext, sym: PSym) = 
+  # it adds the symbol to the interface if appropriate
+  addDecl(c, sym)
+  AddInterfaceDeclAux(c, sym)
+
+proc addInterfaceOverloadableSymAt(c: PContext, sym: PSym, at: int) = 
+  # it adds the symbol to the interface if appropriate
+  addOverloadableSymAt(c, sym, at)
+  AddInterfaceDeclAux(c, sym)
+
+proc lookUp(c: PContext, n: PNode): PSym = 
+  # Looks up a symbol. Generates an error in case of nil.
+  case n.kind
+  of nkAccQuoted: 
+    result = lookup(c, n.sons[0])
+  of nkSym: 
+    #
+    #      result := SymtabGet(c.Tab, n.sym.name);
+    #      if result = nil then
+    #        liMessage(n.info, errUndeclaredIdentifier, n.sym.name.s); 
+    result = n.sym
+  of nkIdent: 
+    result = SymtabGet(c.Tab, n.ident)
+    if result == nil: liMessage(n.info, errUndeclaredIdentifier, n.ident.s)
+  else: InternalError(n.info, "lookUp")
+  if IntSetContains(c.AmbiguousSymbols, result.id): 
+    liMessage(n.info, errUseQualifier, result.name.s)
+  if result.kind == skStub: loadStub(result)
+  
+proc QualifiedLookUp(c: PContext, n: PNode, ambiguousCheck: bool): PSym = 
+  var 
+    m: PSym
+    ident: PIdent
+  case n.kind
+  of nkIdent: 
+    result = SymtabGet(c.Tab, n.ident)
+    if result == nil: 
+      liMessage(n.info, errUndeclaredIdentifier, n.ident.s)
+    elif ambiguousCheck and IntSetContains(c.AmbiguousSymbols, result.id): 
+      liMessage(n.info, errUseQualifier, n.ident.s)
+  of nkSym: 
+    #
+    #      result := SymtabGet(c.Tab, n.sym.name);
+    #      if result = nil then
+    #        liMessage(n.info, errUndeclaredIdentifier, n.sym.name.s)
+    #      else 
+    result = n.sym
+    if ambiguousCheck and IntSetContains(c.AmbiguousSymbols, result.id): 
+      liMessage(n.info, errUseQualifier, n.sym.name.s)
+  of nkDotExpr: 
+    result = nil
+    m = qualifiedLookUp(c, n.sons[0], false)
+    if (m != nil) and (m.kind == skModule): 
+      ident = nil
+      if (n.sons[1].kind == nkIdent): 
+        ident = n.sons[1].ident
+      elif (n.sons[1].kind == nkAccQuoted) and
+          (n.sons[1].sons[0].kind == nkIdent): 
+        ident = n.sons[1].sons[0].ident
+      if ident != nil: 
+        if m == c.module: 
+          result = StrTableGet(c.tab.stack[ModuleTablePos], ident)
+        else: 
+          result = StrTableGet(m.tab, ident)
+        if result == nil: 
+          liMessage(n.sons[1].info, errUndeclaredIdentifier, ident.s)
+      else: 
+        liMessage(n.sons[1].info, errIdentifierExpected, renderTree(n.sons[1]))
+  of nkAccQuoted: 
+    result = QualifiedLookup(c, n.sons[0], ambiguousCheck)
+  else: 
+    result = nil              #liMessage(n.info, errIdentifierExpected, '')
+  if (result != nil) and (result.kind == skStub): loadStub(result)
+  
+proc InitOverloadIter(o: var TOverloadIter, c: PContext, n: PNode): PSym = 
+  var ident: PIdent
+  result = nil
+  case n.kind
+  of nkIdent: 
+    o.stackPtr = c.tab.tos
+    o.mode = oimNoQualifier
+    while (result == nil): 
+      dec(o.stackPtr)
+      if o.stackPtr < 0: break 
+      result = InitIdentIter(o.it, c.tab.stack[o.stackPtr], n.ident)
+  of nkSym: 
+    result = n.sym
+    o.mode = oimDone #
+                     #      o.stackPtr := c.tab.tos;
+                     #      o.mode := oimNoQualifier;
+                     #      while (result = nil) do begin
+                     #        dec(o.stackPtr);
+                     #        if o.stackPtr < 0 then break;
+                     #        result := InitIdentIter(o.it, c.tab.stack[o.stackPtr], n.sym.name);
+                     #      end; 
+  of nkDotExpr: 
+    o.mode = oimOtherModule
+    o.m = qualifiedLookUp(c, n.sons[0], false)
+    if (o.m != nil) and (o.m.kind == skModule): 
+      ident = nil
+      if (n.sons[1].kind == nkIdent): 
+        ident = n.sons[1].ident
+      elif (n.sons[1].kind == nkAccQuoted) and
+          (n.sons[1].sons[0].kind == nkIdent): 
+        ident = n.sons[1].sons[0].ident
+      if ident != nil: 
+        if o.m == c.module: 
+          # a module may access its private members:
+          result = InitIdentIter(o.it, c.tab.stack[ModuleTablePos], ident)
+          o.mode = oimSelfModule
+        else: 
+          result = InitIdentIter(o.it, o.m.tab, ident)
+      else: 
+        liMessage(n.sons[1].info, errIdentifierExpected, renderTree(n.sons[1]))
+  of nkAccQuoted: 
+    result = InitOverloadIter(o, c, n.sons[0])
+  of nkSymChoice: 
+    o.mode = oimSymChoice
+    result = n.sons[0].sym
+    o.stackPtr = 1
+  else: 
+    nil
+  if (result != nil) and (result.kind == skStub): loadStub(result)
+  
+proc nextOverloadIter(o: var TOverloadIter, c: PContext, n: PNode): PSym = 
+  case o.mode
+  of oimDone: 
+    result = nil
+  of oimNoQualifier: 
+    if n.kind == nkAccQuoted: 
+      result = nextOverloadIter(o, c, n.sons[0]) # BUGFIX
+    elif o.stackPtr >= 0: 
+      result = nextIdentIter(o.it, c.tab.stack[o.stackPtr])
+      while (result == nil): 
+        dec(o.stackPtr)
+        if o.stackPtr < 0: break 
+        result = InitIdentIter(o.it, c.tab.stack[o.stackPtr], o.it.name) # BUGFIX: 
+                                                                         # o.it.name <-> n.ident
+    else: 
+      result = nil
+  of oimSelfModule: 
+    result = nextIdentIter(o.it, c.tab.stack[ModuleTablePos])
+  of oimOtherModule: 
+    result = nextIdentIter(o.it, o.m.tab)
+  of oimSymChoice: 
+    if o.stackPtr < sonsLen(n): 
+      result = n.sons[o.stackPtr].sym
+      inc(o.stackPtr)
+    else: 
+      result = nil
+  if (result != nil) and (result.kind == skStub): loadStub(result)
+  
\ No newline at end of file