closures have an object type field so that we can perform correct deepCopy() for the BoehmGC target

compiler/ccgstmts.nim

@@ -164,11 +164,11 @@ proc genBreakState(p: BProc, n: PNode) =
   if n.sons[0].kind == nkClosure:
     # XXX this produces quite inefficient code!
     initLocExpr(p, n.sons[0].sons[1], a)
-    lineF(p, cpsStmts, "if (((NI*) $1)[0] < 0) break;$n", [rdLoc(a)])
+    lineF(p, cpsStmts, "if (((NI*) $1)[1] < 0) break;$n", [rdLoc(a)])
   else:
     initLocExpr(p, n.sons[0], a)
-    # the environment is guaranteed to contain the 'state' field at offset 0:
-    lineF(p, cpsStmts, "if ((((NI*) $1.ClE_0)[0]) < 0) break;$n", [rdLoc(a)])
+    # the environment is guaranteed to contain the 'state' field at offset 1:
+    lineF(p, cpsStmts, "if ((((NI*) $1.ClE_0)[1]) < 0) break;$n", [rdLoc(a)])
   #  lineF(p, cpsStmts, "if (($1) < 0) break;$n", [rdLoc(a)])
 
 proc genVarPrototypeAux(m: BModule, sym: PSym)

compiler/ccgtypes.nim

@@ -12,6 +12,7 @@
 # ------------------------- Name Mangling --------------------------------
 
 import sighashes
+from lowerings import createObj
 
 proc isKeyword(w: PIdent): bool =
   # Nim and C++ share some keywords
@@ -1092,7 +1093,8 @@ proc fakeClosureType(owner: PSym): PType =
   result = newType(tyTuple, owner)
   result.rawAddSon(newType(tyPointer, owner))
   var r = newType(tyRef, owner)
-  r.rawAddSon(newType(tyTuple, owner))
+  let obj = createObj(owner, owner.info, final=false)
+  r.rawAddSon(obj)
   result.rawAddSon(r)
 
 type

compiler/lambdalifting.nim

@@ -142,7 +142,7 @@ proc createStateField(iter: PSym): PSym =
 proc createEnvObj(owner: PSym; info: TLineInfo): PType =
   # YYY meh, just add the state field for every closure for now, it's too
   # hard to figure out if it comes from a closure iterator:
-  result = createObj(owner, info)
+  result = createObj(owner, info, final=false)
   rawAddField(result, createStateField(owner))
 
 proc getIterResult(iter: PSym): PSym =

compiler/lowerings.nim

@@ -109,17 +109,19 @@ proc lowerSwap*(n: PNode; owner: PSym): PNode =
   result.add newFastAsgnStmt(n[1], n[2])
   result.add newFastAsgnStmt(n[2], tempAsNode)
 
-proc createObj*(owner: PSym, info: TLineInfo): PType =
+proc createObj*(owner: PSym, info: TLineInfo; final=true): PType =
   result = newType(tyObject, owner)
-  rawAddSon(result, nil)
-  incl result.flags, tfFinal
+  if final:
+    rawAddSon(result, nil)
+    incl result.flags, tfFinal
+  else:
+    rawAddSon(result, getCompilerProc("RootObj").typ)
   result.n = newNodeI(nkRecList, info)
-  when true:
-    let s = newSym(skType, getIdent("Env_" & info.toFilename),
-                   owner, info)
-    incl s.flags, sfAnon
-    s.typ = result
-    result.sym = s
+  let s = newSym(skType, getIdent("Env_" & info.toFilename),
+                  owner, info)
+  incl s.flags, sfAnon
+  s.typ = result
+  result.sym = s
 
 proc rawAddField*(obj: PType; field: PSym) =
   assert field.kind == skField

lib/system.nim

@@ -413,7 +413,7 @@ type
     ## is an int type ranging from one to the maximum value
     ## of an int. This type is often useful for documentation and debugging.
 
-  RootObj* {.exportc: "TNimObject", inheritable.} =
+  RootObj* {.compilerProc, inheritable.} =
     object ## the root of Nim's object hierarchy. Objects should
            ## inherit from RootObj or one of its descendants. However,
            ## objects that have no ancestor are allowed.
@@ -3269,7 +3269,7 @@ when not defined(JS): #and not defined(nimscript):
     proc finished*[T: proc](x: T): bool {.noSideEffect, inline.} =
       ## can be used to determine if a first class iterator has finished.
       {.emit: """
-      `result` = *((NI*) `x`.ClE_0) < 0;
+      `result` = ((NI*) `x`.ClE_0)[1] < 0;
       """.}
 
 elif defined(JS):

lib/system/deepcopy.nim

@@ -148,11 +148,11 @@ proc genericDeepCopyAux(dest, src: pointer, mt: PNimType; tab: var PtrTable) =
             let realType = x.typ
             sysAssert realType == mt, " types do differ"
           # this version should work for any possible GC:
-          let size = if mt.base.kind == tyObject: cast[ptr PNimType](s2)[].size else: mt.base.size
-          let z = newObj(mt, size)
+          let typ = if mt.base.kind == tyObject: cast[ptr PNimType](s2)[] else: mt.base
+          let z = newObj(mt, typ.size)
           unsureAsgnRef(cast[PPointer](dest), z)
           tab.put(s2, z)
-          genericDeepCopyAux(z, s2, mt.base, tab)
+          genericDeepCopyAux(z, s2, typ, tab)
       else:
         unsureAsgnRef(cast[PPointer](dest), z)
   of tyPtr:

tests/closure/tboehmdeepcopy.nim

@@ -0,0 +1,17 @@
+discard """
+  cmd: "nim c --gc:boehm $options $file"
+  output: '''meep'''
+"""
+
+proc callit(it: proc ()) =
+  it()
+
+proc main =
+  var outer = "meep"
+  proc x =
+    echo outer
+  var y: proc()
+  deepCopy(y, x)
+  callit(y)
+
+main()