deepCopy is instantiated when its corresponding type is instantiated

compiler/ccgtypes.nim

@@ -898,7 +898,7 @@ include ccgtrav
 
 proc genDeepCopyProc(m: BModule; s: PSym; result: PRope) =
   genProc(m, s)
-  appf(m.s[cfsTypeInit3], "$1.deepcopy = (N_NIMCALL_PTR(void*, void*)) $2;$n",
+  appf(m.s[cfsTypeInit3], "$1.deepcopy =(N_NIMCALL_PTR(void*,)(void*))$2;$n",
      [result, s.loc.r])
 
 proc genTypeInfo(m: BModule, t: PType): PRope =

compiler/sem.nim

@@ -371,6 +371,8 @@ proc myOpen(module: PSym): PPassContext =
   c.semInferredLambda = semInferredLambda
   c.semGenerateInstance = generateInstance
   c.semTypeNode = semTypeNode
+  c.instDeepCopy = sigmatch.instDeepCopy
+
   pushProcCon(c, module)
   pushOwner(c.module)
   c.importTable = openScope(c)

compiler/semdata.nim

@@ -92,6 +92,9 @@ type
     lastGenericIdx*: int      # used for the generics stack
     hloLoopDetector*: int     # used to prevent endless loops in the HLO
     inParallelStmt*: int
+    instDeepCopy*: proc (c: PContext; dc: PSym; t: PType;
+                         info: TLineInfo): PSym {.nimcall.}
+
    
 proc makeInstPair*(s: PSym, inst: PInstantiation): TInstantiationPair =
   result.genericSym = s

compiler/semstmts.nim

@@ -1029,7 +1029,11 @@ proc semOverride(c: PContext, s: PSym, n: PNode) =
         sameType(s.typ.sons[1], s.typ.sons[0]):
       # Note: we store the deepCopy in the base of the pointer to mitigate
       # the problem that pointers are structural types:
-      let t = s.typ.sons[1].skipTypes(abstractInst).lastSon.skipTypes(abstractInst)
+      var t = s.typ.sons[1].skipTypes(abstractInst).lastSon.skipTypes(abstractInst)
+      while true:
+        if t.kind == tyGenericBody: t = t.lastSon
+        elif t.kind == tyGenericInvokation: t = t.sons[0]
+        else: break
       if t.kind in {tyObject, tyDistinct, tyEnum}:
         if t.deepCopy.isNil: t.deepCopy = s
         else: 
@@ -1044,6 +1048,7 @@ proc semOverride(c: PContext, s: PSym, n: PNode) =
   of "=": discard
   else: localError(n.info, errGenerated,
                    "'destroy' or 'deepCopy' expected for 'override'")
+  incl(s.flags, sfUsed)
 
 type
   TProcCompilationSteps = enum

compiler/semtypinst.nim

@@ -299,6 +299,18 @@ proc handleGenericInvokation(cl: var TReplTypeVars, t: PType): PType =
   if newbody.isGenericAlias: newbody = newbody.skipGenericAlias
   rawAddSon(result, newbody)
   checkPartialConstructedType(cl.info, newbody)
+  let dc = newbody.deepCopy
+  if dc != nil and sfFromGeneric notin newbody.deepCopy.flags:
+    # 'deepCopy' needs to be instantiated for
+    # generics *when the type is constructed*:
+    newbody.deepCopy = cl.c.instDeepCopy(cl.c, dc, result, cl.info)
+    when false:
+      var bindings: TIdTable
+      initIdTable(bindings)
+      debug newbody
+      bindings.idTablePut(dc.ast[genericParamsPos].sons[0].typ, newbody)
+      newbody.deepCopy = cl.c.semGenerateInstance(cl.c, dc, bindings, cl.info)
+      assert sfFromGeneric in newbody.deepCopy.flags
 
 proc eraseVoidParams*(t: PType) =
   if t.sons[0] != nil and t.sons[0].kind == tyEmpty:

compiler/sigmatch.nim

@@ -1482,6 +1482,18 @@ proc argtypeMatches*(c: PContext, f, a: PType): bool =
   # instantiate generic converters for that
   result = res != nil
 
+proc instDeepCopy*(c: PContext; dc: PSym; t: PType; info: TLineInfo): PSym {.
+                    procvar.} =
+  var m: TCandidate
+  initCandidate(c, m, dc.typ)
+  var f = dc.typ.sons[1]
+  if f.kind in {tyRef, tyPtr}: f = f.lastSon
+  if typeRel(m, f, t) == isNone:
+    localError(info, errGenerated, "cannot instantiate 'deepCopy'")
+  else:
+    result = c.semGenerateInstance(c, dc, m.bindings, info)
+    assert sfFromGeneric in result.flags
+
 include suggest
 
 when not declared(tests):

doc/manual.txt

@@ -4386,6 +4386,8 @@ like ``let v = expr``, ``var v = expr``, ``parameter = defaultValue`` or for
 parameter passing no assignment is performed. The ``override`` pragma is
 optional for overriding ``=``.
 
+**Note**: Overriding of operator ``=`` is not yet implemented.
+
 
 destructors
 -----------
@@ -4446,6 +4448,9 @@ Be aware that destructors are not called for objects allocated with ``new``.
 This may change in future versions of language, but for now the ``finalizer``
 parameter to ``new`` has to be used.
 
+**Note**: Destructors are still experimental and the spec might change
+significantly in order to incorporate an escape analysis.
+
 
 deepCopy
 --------

lib/system/deepcopy.nim

@@ -82,17 +82,16 @@ proc genericDeepCopyAux(dest, src: pointer, mt: PNimType) =
       genericDeepCopyAux(cast[pointer](d +% i*% mt.base.size),
                          cast[pointer](s +% i*% mt.base.size), mt.base)
   of tyRef:
-    if mt.base.deepcopy != nil:
-      let z = mt.base.deepcopy(cast[PPointer](src)[])
+    let s2 = cast[PPointer](src)[]
+    if s2 == nil:
+      unsureAsgnRef(cast[PPointer](dest), s2)
+    elif mt.base.deepcopy != nil:
+      let z = mt.base.deepcopy(s2)
       unsureAsgnRef(cast[PPointer](dest), z)
     else:
       # we modify the header of the cell temporarily; instead of the type
       # field we store a forwarding pointer. XXX This is bad when the cloning
       # fails due to OOM etc.
-      let s2 = cast[PPointer](src)[]
-      if s2 == nil:
-        unsureAsgnRef(cast[PPointer](dest), s2)
-        return
       when declared(usrToCell):
         # unfortunately we only have cycle detection for our native GCs.
         let x = usrToCell(s2)
@@ -116,10 +115,11 @@ proc genericDeepCopyAux(dest, src: pointer, mt: PNimType) =
         genericDeepCopyAux(z, s2, realType.base)        
   of tyPtr:
     # no cycle check here, but also not really required
-    if mt.base.deepcopy != nil:
-      cast[PPointer](dest)[] = mt.base.deepcopy(cast[PPointer](s)[])
+    let s2 = cast[PPointer](src)[]
+    if s2 != nil and mt.base.deepcopy != nil:
+      cast[PPointer](dest)[] = mt.base.deepcopy(s2)
     else:
-      cast[PPointer](dest)[] = cast[PPointer](s)[]
+      cast[PPointer](dest)[] = s2
   else:
     copyMem(dest, src, mt.size)
 

tests/parallel/tdeepcopy2.nim

@@ -0,0 +1,35 @@
+discard """
+  output: '''called deepCopy for int
+called deepCopy for int
+done999 999
+"""
+
+import threadpool
+
+
+type
+  Bar[T] = object
+    x: T
+
+proc deepCopy[T](b: ref Bar[T]): ref Bar[T] {.override.} =
+  result.new
+  result.x = b.x
+  when T is int:
+    echo "called deepCopy for int"
+  else:
+    echo "called deepCopy for something else"
+
+proc foo(b: ref Bar[int]): int = 999
+
+# test that the disjoint checker deals with 'a = spawn f(); g = spawn f()':
+
+proc main =
+  var dummy: ref Bar[int]
+  new(dummy)
+  dummy.x = 44
+  parallel:
+    let f = spawn foo(dummy)
+    let b = spawn foo(dummy)
+  echo "done", f, " ", b
+
+main()

todo.txt

@@ -1,6 +1,7 @@
 version 0.10
 ============
 
+- use the effect system for static deadlock prevention
 - Test nimfix on various babel packages
 - deprecate recursive tuples; tuple needs laxer type checking
 - string case should require an 'else'
@@ -20,9 +21,7 @@ version 0.9.6
 Concurrency
 -----------
 
-- 'deepCopy' needs to be instantiated for
-  generics *when the type is constructed*
-- test 'deepCopy'
+- test 'deepCopy' for closures
 
 - implement 'foo[1..4] = spawn(f[4..7])'
 - document the new 'spawn' and 'parallel' statements
@@ -117,7 +116,6 @@ Concurrency/Effect system
   provide a ``syncgc`` pragma to trigger compiler injection --> more general:
   an ``injectLoop`` pragma
 - 'writes: []' effect; track reads/writes for shared types
-- use the effect system for static deadlock prevention and race detection
 - ``~`` operator for effects
 - introduce 'noaddr' pragma to prevent taking the address of a location; this
   is very handy to prevent aliasing of global data