fixes #2470, fixes #1354

8 files changed, 99 insertions, 53 deletions

diff --git a/compiler/ccgtypes.nim b/compiler/ccgtypes.nim
index 9cbb81fad..3742fd2fd 100644
--- a/compiler/ccgtypes.nim
+++ b/compiler/ccgtypes.nim
@@ -111,7 +111,7 @@ proc mapSetType(typ: PType): TCTypeKind =
   else: result = ctArray
 
 proc mapType(typ: PType): TCTypeKind =
-  ## Maps a nimrod type to a C type
+  ## Maps a Nim type to a C type
   case typ.kind
   of tyNone, tyStmt: result = ctVoid
   of tyBool: result = ctBool
diff --git a/compiler/sem.nim b/compiler/sem.nim
index 2e13c88c3..346a17df1 100644
--- a/compiler/sem.nim
+++ b/compiler/sem.nim
@@ -89,6 +89,10 @@ proc fitNode(c: PContext, formal: PType, arg: PNode): PNode =
       let x = result.skipConv
       if x.kind == nkPar and formal.kind != tyExpr:
         changeType(x, formal, check=true)
+      else:
+        result = skipHiddenSubConv(result)
+        #result.typ = takeType(formal, arg.typ)
+        #echo arg.info, " picked ", result.typ.typeToString
 
 proc inferWithMetatype(c: PContext, formal: PType,
                        arg: PNode, coerceDistincts = false): PNode
diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim
index a2e3b9d33..21fc4ec40 100644
--- a/compiler/semexprs.nim
+++ b/compiler/semexprs.nim
@@ -535,44 +535,45 @@ proc semArrayConstr(c: PContext, n: PNode, flags: TExprFlags): PNode =
       result.sons[i] = fitNode(c, typ, result.sons[i])
   result.typ.sons[0] = makeRangeType(c, 0, sonsLen(result) - 1, n.info)
 
-proc fixAbstractType(c: PContext, n: PNode) =
-  # XXX finally rewrite that crap!
-  for i in countup(1, sonsLen(n) - 1):
-    var it = n.sons[i]
-    case it.kind
-    of nkHiddenStdConv, nkHiddenSubConv:
-      if it.sons[1].kind == nkBracket:
-        it.sons[1].typ = arrayConstrType(c, it.sons[1])
-        #it.sons[1] = semArrayConstr(c, it.sons[1])
-      if skipTypes(it.typ, abstractVar).kind in {tyOpenArray, tyVarargs}:
-        #if n.sons[0].kind == nkSym and IdentEq(n.sons[0].sym.name, "[]="):
-        #  debug(n)
-
-        var s = skipTypes(it.sons[1].typ, abstractVar)
-        if s.kind == tyArrayConstr and s.sons[1].kind == tyEmpty:
-          s = copyType(s, getCurrOwner(), false)
-          skipTypes(s, abstractVar).sons[1] = elemType(
-              skipTypes(it.typ, abstractVar))
-          it.sons[1].typ = s
-        elif s.kind == tySequence and s.sons[0].kind == tyEmpty:
-          s = copyType(s, getCurrOwner(), false)
-          skipTypes(s, abstractVar).sons[0] = elemType(
-              skipTypes(it.typ, abstractVar))
-          it.sons[1].typ = s
-
-      elif skipTypes(it.sons[1].typ, abstractVar).kind in
-          {tyNil, tyArrayConstr, tyTuple, tySet}:
-        var s = skipTypes(it.typ, abstractVar)
-        if s.kind != tyExpr:
-          changeType(it.sons[1], s, check=true)
-        n.sons[i] = it.sons[1]
-    of nkBracket:
-      # an implicitly constructed array (passed to an open array):
-      n.sons[i] = semArrayConstr(c, it, {})
-    else:
-      discard
-      #if (it.typ == nil):
-      #  InternalError(it.info, "fixAbstractType: " & renderTree(it))
+template fixAbstractType(c: PContext, n: PNode) =
+  when false:
+    # XXX finally rewrite that crap!
+    for i in countup(1, sonsLen(n) - 1):
+      var it = n.sons[i]
+      case it.kind
+      of nkHiddenStdConv, nkHiddenSubConv:
+        if it.sons[1].kind == nkBracket:
+          it.sons[1].typ = arrayConstrType(c, it.sons[1])
+          #it.sons[1] = semArrayConstr(c, it.sons[1])
+        if skipTypes(it.typ, abstractVar).kind in {tyOpenArray, tyVarargs}:
+          #if n.sons[0].kind == nkSym and IdentEq(n.sons[0].sym.name, "[]="):
+          #  debug(n)
+
+          var s = skipTypes(it.sons[1].typ, abstractVar)
+          if s.kind == tyArrayConstr and s.sons[1].kind == tyEmpty:
+            s = copyType(s, getCurrOwner(), false)
+            skipTypes(s, abstractVar).sons[1] = elemType(
+                skipTypes(it.typ, abstractVar))
+            it.sons[1].typ = s
+          elif s.kind == tySequence and s.sons[0].kind == tyEmpty:
+            s = copyType(s, getCurrOwner(), false)
+            skipTypes(s, abstractVar).sons[0] = elemType(
+                skipTypes(it.typ, abstractVar))
+            it.sons[1].typ = s
+
+        elif skipTypes(it.sons[1].typ, abstractVar).kind in
+            {tyNil, tyArrayConstr, tyTuple, tySet}:
+          var s = skipTypes(it.typ, abstractVar)
+          if s.kind != tyExpr:
+            changeType(it.sons[1], s, check=true)
+          n.sons[i] = it.sons[1]
+      of nkBracket:
+        # an implicitly constructed array (passed to an open array):
+        n.sons[i] = semArrayConstr(c, it, {})
+      else:
+        discard
+        #if (it.typ == nil):
+        #  InternalError(it.info, "fixAbstractType: " & renderTree(it))
 
 proc skipObjConv(n: PNode): PNode =
   case n.kind
diff --git a/compiler/semfold.nim b/compiler/semfold.nim
index 796dde9a6..941d47bb4 100644
--- a/compiler/semfold.nim
+++ b/compiler/semfold.nim
@@ -431,7 +431,8 @@ proc evalOp(m: TMagic, n, a, b, c: PNode): PNode =
      mExit, mInc, ast.mDec, mEcho, mSwap, mAppendStrCh,
      mAppendStrStr, mAppendSeqElem, mSetLengthStr, mSetLengthSeq,
      mParseExprToAst, mParseStmtToAst, mExpandToAst, mTypeTrait, mDotDot,
-     mNLen..mNError, mEqRef, mSlurp, mStaticExec, mNGenSym, mSpawn, mParallel:
+     mNLen..mNError, mEqRef, mSlurp, mStaticExec, mNGenSym, mSpawn,
+     mParallel, mPlugin:
     discard
   else: internalError(a.info, "evalOp(" & $m & ')')
 
@@ -544,7 +545,7 @@ proc foldConv*(n, a: PNode; check = false): PNode =
     discard
   else:
     result = a
-    result.typ = n.typ
+    result.typ = takeType(n.typ, a.typ)
 
 proc getArrayConstr(m: PSym, n: PNode): PNode =
   if n.kind == nkBracket:
diff --git a/compiler/seminst.nim b/compiler/seminst.nim
index f72e2dc5b..b2aef63a8 100644
--- a/compiler/seminst.nim
+++ b/compiler/seminst.nim
@@ -187,7 +187,9 @@ proc instantiateProcType(c: PContext, pt: TIdTable,
       let param = copySym(oldParam)
       param.owner = prc
       param.typ = result.sons[i]
-      param.ast = oldParam.ast.copyTree
+      if oldParam.ast != nil:
+        param.ast = fitNode(c, param.typ, oldParam.ast)
+
       # don't be lazy here and call replaceTypeVarsN(cl, originalParams[i])!
       result.n.sons[i] = newSymNode(param)
       addDecl(c, param)
diff --git a/compiler/sigmatch.nim b/compiler/sigmatch.nim
index b5f943c5b..2a9d15b5a 100644
--- a/compiler/sigmatch.nim
+++ b/compiler/sigmatch.nim
@@ -1200,15 +1200,6 @@ proc isInlineIterator*(t: PType): bool =
   result = t.kind == tyIter or
           (t.kind == tyBuiltInTypeClass and t.base.kind == tyIter)
 
-proc isEmptyContainer*(t: PType): bool =
-  case t.kind
-  of tyExpr, tyNil: result = true
-  of tyArray, tyArrayConstr: result = t.sons[1].kind == tyEmpty
-  of tySet, tySequence, tyOpenArray, tyVarargs:
-    result = t.sons[0].kind == tyEmpty
-  of tyGenericInst: result = isEmptyContainer(t.lastSon)
-  else: result = false
-
 proc incMatches(m: var TCandidate; r: TTypeRelation; convMatch = 1) =
   case r
   of isConvertible, isIntConv: inc(m.convMatches, convMatch)
@@ -1313,7 +1304,7 @@ proc paramTypesMatchAux(m: var TCandidate, f, argType: PType,
     if arg.typ == nil:
       result = arg
     elif skipTypes(arg.typ, abstractVar-{tyTypeDesc}).kind == tyTuple:
-      result = implicitConv(nkHiddenStdConv, f, copyTree(arg), m, c)
+      result = implicitConv(nkHiddenSubConv, f, arg, m, c)
     elif arg.typ.isEmptyContainer:
       result = arg.copyTree
       result.typ = getInstantiatedType(c, arg, m, f)
@@ -1328,7 +1319,7 @@ proc paramTypesMatchAux(m: var TCandidate, f, argType: PType,
     inc(m.exactMatches)
     result = arg
     if skipTypes(f, abstractVar-{tyTypeDesc}).kind in {tyTuple}:
-      result = implicitConv(nkHiddenStdConv, f, arg, m, c)
+      result = implicitConv(nkHiddenSubConv, f, arg, m, c)
   of isNone:
     # do not do this in ``typeRel`` as it then can't infere T in ``ref T``:
     if a.kind in {tyProxy, tyUnknown}:
@@ -1580,6 +1571,8 @@ proc matchesAux(c: PContext, n, nOrig: PNode,
           #assert(container == nil)
           if container.isNil:
             container = newNodeIT(nkBracket, n.sons[a].info, arrayConstr(c, arg))
+          else:
+            incrIndexType(container.typ)
           addSon(container, arg)
           setSon(m.call, formal.position + 1,
                  implicitConv(nkHiddenStdConv, formal.typ, container, m, c))
diff --git a/compiler/transf.nim b/compiler/transf.nim
index 2143b6bec..3bdbdfadd 100644
--- a/compiler/transf.nim
+++ b/compiler/transf.nim
@@ -379,6 +379,9 @@ proc transformConv(c: PTransf, n: PNode): PTransNode =
       result = transformSons(c, n)
   of tyOpenArray, tyVarargs:
     result = transform(c, n.sons[1])
+    PNode(result).typ = takeType(n.typ, n.sons[1].typ)
+    #echo n.info, " came here and produced ", typeToString(PNode(result).typ),
+    #   " from ", typeToString(n.typ), " and ", typeToString(n.sons[1].typ)
   of tyCString:
     if source.kind == tyString:
       result = newTransNode(nkStringToCString, n, 1)
diff --git a/compiler/types.nim b/compiler/types.nim
index 7f05e7051..1b30afc76 100644
--- a/compiler/types.nim
+++ b/compiler/types.nim
@@ -1439,3 +1439,45 @@ proc skipConv*(n: PNode): PNode =
 proc skipConvTakeType*(n: PNode): PNode =
   result = n.skipConv
   result.typ = n.typ
+
+proc isEmptyContainer*(t: PType): bool =
+  case t.kind
+  of tyExpr, tyNil: result = true
+  of tyArray, tyArrayConstr: result = t.sons[1].kind == tyEmpty
+  of tySet, tySequence, tyOpenArray, tyVarargs:
+    result = t.sons[0].kind == tyEmpty
+  of tyGenericInst: result = isEmptyContainer(t.lastSon)
+  else: result = false
+
+proc takeType*(formal, arg: PType): PType =
+  # param: openArray[string] = []
+  # [] is an array constructor of length 0 of type string!
+  if arg.kind == tyNil:
+    # and not (formal.kind == tyProc and formal.callConv == ccClosure):
+    result = formal
+  elif formal.kind in {tyOpenArray, tyVarargs, tySequence} and
+      arg.isEmptyContainer:
+    let a = copyType(arg.skipTypes({tyGenericInst}), arg.owner, keepId=false)
+    a.sons[ord(arg.kind in {tyArray, tyArrayConstr})] = formal.sons[0]
+    result = a
+  elif formal.kind == tySet and arg.kind == tySet:
+    result = formal
+  else:
+    result = arg
+
+proc skipHiddenSubConv*(n: PNode): PNode =
+  if n.kind == nkHiddenSubConv:
+    # param: openArray[string] = []
+    # [] is an array constructor of length 0 of type string!
+    let formal = n.typ
+    result = n.sons[1]
+    let arg = result.typ
+    let dest = takeType(formal, arg)
+    if dest == arg and formal.kind != tyExpr:
+      #echo n.info, " came here for ", formal.typeToString
+      result = n
+    else:
+      result = copyTree(result)
+      result.typ = dest
+  else:
+    result = n