fixed #597

compiler/astalgo.nim

@@ -432,6 +432,8 @@ proc debugTree(n: PNode, indent: int, maxRecDepth: int): PRope =
 proc debug(n: PSym) =
   if n == nil:
     writeln(stdout, "null")
+  elif n.kind == skUnknown:
+    writeln(stdout, "skUnknown")
   else:
     #writeln(stdout, ropeToStr(symToYaml(n, 0, 1)))
     writeln(stdout, ropeToStr(ropef("$1_$2: $3, $4", [

compiler/msgs.nim

@@ -93,6 +93,7 @@ type
     errNewSectionExpected, errWhitespaceExpected, errXisNoValidIndexFile, 
     errCannotRenderX, errVarVarTypeNotAllowed, errInstantiateXExplicitely,
     errOnlyACallOpCanBeDelegator, errUsingNoSymbol,
+    errDestructorNotGenericEnough,
     
     errXExpectsTwoArguments, 
     errXExpectsObjectTypes, errXcanNeverBeOfThisSubtype, errTooManyIterations, 
@@ -322,6 +323,8 @@ const
     errInstantiateXExplicitely: "instantiate '$1' explicitely",
     errOnlyACallOpCanBeDelegator: "only a call operator can be a delegator",
     errUsingNoSymbol: "'$1' is not a variable, constant or a proc name",
+    errDestructorNotGenericEnough: "Destructor signarue is too specific. " &
+                                   "A destructor must be associated will all instantiations of a generic type",
     errXExpectsTwoArguments: "\'$1\' expects two arguments", 
     errXExpectsObjectTypes: "\'$1\' expects object types",
     errXcanNeverBeOfThisSubtype: "\'$1\' can never be of this subtype", 

compiler/semdestruct.nim

@@ -9,6 +9,7 @@
 
 ## This module implements destructors.
 
+# included from sem.nim
 
 # special marker values that indicates that we are
 # 1) AnalyzingDestructor: currently analyzing the type for destructor 
@@ -25,10 +26,22 @@ var
   destructorPragma = newIdentNode(getIdent"destructor", unknownLineInfo())
   rangeDestructorProc*: PSym
 
-proc instantiateDestructor(c: PContext, typ: PType): bool
+proc instantiateDestructor(c: PContext, typ: PType): PType
 
 proc doDestructorStuff(c: PContext, s: PSym, n: PNode) =
-  let t = s.typ.sons[1].skipTypes({tyVar})
+  var t = s.typ.sons[1].skipTypes({tyVar})
+  if t.kind == tyGenericInvokation:
+    for i in 1 .. <t.sonsLen:
+      if t.sons[i].kind != tyGenericParam:
+        localError(n.info, errDestructorNotGenericEnough)
+        return
+    t = t.base
+  elif t.kind == tyCompositeTypeClass:
+    t = t.base
+    if t.kind != tyGenericBody:
+      localError(n.info, errDestructorNotGenericEnough)
+      return
+  
   t.destructor = s
   # automatically insert calls to base classes' destructors
   if n.sons[bodyPos].kind != nkEmpty:
@@ -36,15 +49,17 @@ proc doDestructorStuff(c: PContext, s: PSym, n: PNode) =
       # when inheriting directly from object
       # there will be a single nil son
       if t.sons[i] == nil: continue
-      if instantiateDestructor(c, t.sons[i]):
+      let destructableT = instantiateDestructor(c, t.sons[i])
+      if destructableT != nil:
         n.sons[bodyPos].addSon(newNode(nkCall, t.sym.info, @[
-            useSym(t.sons[i].destructor),
+            useSym(destructableT.destructor),
             n.sons[paramsPos][1][0]]))
 
 proc destroyField(c: PContext, field: PSym, holder: PNode): PNode =
-  if instantiateDestructor(c, field.typ):
+  let destructableT = instantiateDestructor(c, field.typ)
+  if destructableT != nil:
     result = newNode(nkCall, field.info, @[
-      useSym(field.typ.destructor),
+      useSym(destructableT.destructor),
       newNode(nkDotExpr, field.info, @[holder, useSym(field)])])
 
 proc destroyCase(c: PContext, n: PNode, holder: PNode): PNode =
@@ -105,26 +120,35 @@ proc generateDestructor(c: PContext, t: PType): PNode =
   # base classes' destructors will be automatically called by
   # semProcAux for both auto-generated and user-defined destructors
 
-proc instantiateDestructor(c: PContext, typ: PType): bool =
+proc instantiateDestructor(c: PContext, typ: PType): PType =
-  # returns true if the type already had a user-defined
+  # returns nil if a variable of type `typ` doesn't require a
-  # destructor or if the compiler generated a default
+  # destructor. Otherwise, returns the type, which holds the 
-  # member-wise one
+  # destructor that must be used for the varialbe.
-  var t = skipTypes(typ, {tyConst, tyMutable})
+  # The destructor is either user-defined or automatically
+  # generated by the compiler in a member-wise fashion.
+  var t = skipTypes(typ, {tyConst, tyMutable}).skipGenericAlias
+  let typeHoldingUserDefinition = if t.kind == tyGenericInst: t.base
+                                  else: t
   
-  if t.destructor != nil:
+  if typeHoldingUserDefinition.destructor != nil:
     # XXX: This is not entirely correct for recursive types, but we need
     # it temporarily to hide the "destroy is already defined" problem
-    return t.destructor notin [analyzingDestructor, destructorIsTrivial]
+    if typeHoldingUserDefinition.destructor notin
+        [analyzingDestructor, destructorIsTrivial]:
+      return typeHoldingUserDefinition
+    else:
+      return nil
   
+  t = t.skipTypes({tyGenericInst})
   case t.kind
   of tySequence, tyArray, tyArrayConstr, tyOpenArray, tyVarargs:
-    if instantiateDestructor(c, t.sons[0]):
+    if instantiateDestructor(c, t.sons[0]) != nil:
       if rangeDestructorProc == nil:
         rangeDestructorProc = searchInScopes(c, getIdent"nimDestroyRange")
       t.destructor = rangeDestructorProc
-      return true
+      return t
     else:
-      return false
+      return nil
   of tyTuple, tyObject:
     t.destructor = analyzingDestructor
     let generated = generateDestructor(c, t)
@@ -139,21 +163,21 @@ proc instantiateDestructor(c: PContext, typ: PType): bool =
           emptyNode,
           newNode(nkIdentDefs, i, @[
             newIdentNode(destructorParam, i),
-            useSym(t.sym),
+            symNodeFromType(c, makeVarType(c, t), t.sym.info),
             emptyNode]),
           ]),
         newNode(nkPragma, i, @[destructorPragma]),
         emptyNode,
         generated
         ])
-      discard semProc(c, fullDef)
+      let semantizedDef = semProc(c, fullDef)
-      internalAssert t.destructor != nil
+      t.destructor = semantizedDef[namePos].sym
-      return true
+      return t
     else:
       t.destructor = destructorIsTrivial
-      return false
+      return nil
   else:
-    return false
+    return nil
 
 proc insertDestructors(c: PContext,
                        varSection: PNode): tuple[outer, inner: PNode] =
@@ -180,8 +204,10 @@ proc insertDestructors(c: PContext,
       varTyp = varId.sym.typ
       info = varId.info
     
-    if varTyp != nil and instantiateDestructor(c, varTyp) and 
+    if varTyp == nil or sfGlobal in varId.sym.flags: continue
-        sfGlobal notin varId.sym.flags:
+    let destructableT = instantiateDestructor(c, varTyp)
+    
+    if destructableT != nil:
       var tryStmt = newNodeI(nkTryStmt, info)
 
       if j < totalVars - 1:
@@ -202,7 +228,7 @@ proc insertDestructors(c: PContext,
       tryStmt.addSon(
         newNode(nkFinally, info, @[
           semStmt(c, newNode(nkCall, info, @[
-            useSym(varTyp.destructor),
+            useSym(destructableT.destructor),
             useSym(varId.sym)]))]))
 
       result.outer = newNodeI(nkStmtList, info)

compiler/semstmts.nim

@@ -86,7 +86,7 @@ include semdestruct
 
 proc semDestructorCheck(c: PContext, n: PNode, flags: TExprFlags) {.inline.} =
   if efAllowDestructor notin flags and n.kind in nkCallKinds+{nkObjConstr}:
-    if instantiateDestructor(c, n.typ):
+    if instantiateDestructor(c, n.typ) != nil:
       localError(n.info, errGenerated,
         "usage of a type with a destructor in a non destructible context")
   # This still breaks too many things:

tests/run/tdestructor.nim

@@ -1,6 +1,18 @@
 discard """
-  output: '''some text
+  output: '''----
-Destructor called!'''
+myobj constructed
+myobj destructed
+----
+mygeneric1 constructed
+mygeneric1 destroyed
+----
+mygeneric2 constructed
+mygeneric2 destroyed
+myobj destroyed
+----
+mygeneric3 constructed
+mygeneric1 destroyed
+'''
 """
 
 type
@@ -8,19 +20,65 @@ type
     x, y: int
     p: pointer
 
+  TMyGeneric1[T] = object
+    x: T
+
+  TMyGeneric2[A, B] = object
+    x: A
+    y: B
+
+  TMyGeneric3[A, B, C] = object
+    x: A
+    y: B
+    z: C
+
 proc destruct(o: var TMyObj) {.destructor.} =
   if o.p != nil: dealloc o.p
-  echo "Destructor called!"
+  echo "myobj destroyed"
+
+proc destroy(o: var TMyGeneric1) {.destructor.} =
+  echo "mygeneric1 destroyed"
+
+proc destroy[A, B](o: var TMyGeneric2[A, B]) {.destructor.} =
+  echo "mygeneric2 destroyed"
 
 proc open: TMyObj =
   # allow for superfluous ()
   result = (TMyObj(x: 1, y: 2, p: alloc(3)))
 
-
 proc `$`(x: TMyObj): string = $x.y
 
-proc main() =
+proc myobj() =
   var x = open()
-  echo "some text"
+  echo "myobj constructed"
+
+proc mygeneric1() =
+  var x = TMyGeneric1[int](x: 10)
+  echo "mygeneric1 constructed"
+
+proc mygeneric2[T](val: T) =
+  var
+    a = open()
+    b = TMyGeneric2[int, T](x: 10, y: val)
+    c = TMyGeneric3[int, int, string](x: 10, y: 20, z: "test")
+
+  echo "mygeneric2 constructed"
+
+proc mygeneric3 =
+  var x = TMyGeneric3[int, string, TMyGeneric1[int]](
+    x: 10, y: "test", z: TMyGeneric1[int](x: 10))
+
+  echo "mygeneric3 constructed"
+
+echo "----"
+myobj()
+
+echo "----"
+mygeneric1()
+
+echo "----"
+mygeneric2[int](10)
+
+echo "----"
+mygeneric3()
 
-main()