Initial import

lib/assign.nim

@@ -0,0 +1,118 @@
+#
+#
+#            Nimrod's Runtime Library
+#        (c) Copyright 2006 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+#when defined(debugGC):
+#  {.define: logAssign.}
+proc genericAssign(dest, src: Pointer, mt: PNimType) {.compilerProc.}
+proc genericAssignAux(dest, src: Pointer, n: ptr TNimNode) =
+  var
+    d = cast[TAddress](dest)
+    s = cast[TAddress](src)
+  case n.kind
+  of nkNone: assert(false)
+  of nkSlot:
+    genericAssign(cast[pointer](d +% n.offset), cast[pointer](s +% n.offset),
+                  n.typ)
+  of nkList: 
+    for i in 0..n.len-1: 
+      genericAssignAux(dest, src, n.sons[i])
+  of nkCase: 
+    copyMem(cast[pointer](d +% n.offset), cast[pointer](s +% n.offset),
+            n.typ.size)
+    var m = selectBranch(src, n)
+    if m != nil: genericAssignAux(dest, src, m)
+
+proc genericAssign(dest, src: Pointer, mt: PNimType) =
+  var
+    d = cast[TAddress](dest)
+    s = cast[TAddress](src)
+
+  assert(mt != nil)
+  case mt.Kind
+  of tySequence:
+    var s2 = cast[ppointer](src)^
+    var seq = cast[PGenericSeq](s2)
+    if s2 == nil:  # this can happen! nil sequences are allowed
+      var x = cast[ppointer](dest)
+      x^ = nil
+      return
+    assert(dest != nil)
+    unsureAsgnRef(cast[ppointer](dest), 
+                  newObj(mt, seq.len * mt.base.size + GenericSeqSize))
+    var dst = cast[taddress](cast[ppointer](dest)^)
+    for i in 0..seq.len-1:
+      genericAssign(
+        cast[pointer](dst +% i*% mt.base.size +% GenericSeqSize),
+        cast[pointer](cast[taddress](s2) +% i *% mt.base.size +%
+                     GenericSeqSize),
+        mt.Base)
+    var dstseq = cast[PGenericSeq](dst)
+    dstseq.len = seq.len
+    dstseq.space = seq.len
+  of tyRecord, tyObject, tyTuple:
+    genericAssignAux(dest, src, mt.node)
+  of tyArray, tyArrayConstr:
+    for i in 0..(mt.size div mt.base.size)-1:
+      genericAssign(cast[pointer](d +% i*% mt.base.size),
+                    cast[pointer](s +% i*% mt.base.size), mt.base)
+  of tyString: # a leaf
+    var s2 = cast[ppointer](s)^
+    if s2 != nil: # nil strings are possible!
+      unsureAsgnRef(cast[ppointer](dest), copyString(cast[mstring](s2)))
+    else:
+      var x = cast[ppointer](dest)
+      x^ = nil
+      return
+  of tyRef:  # BUGFIX: a long time this has been forgotten!
+    unsureAsgnRef(cast[ppointer](dest), cast[ppointer](s)^)
+  else:
+    copyMem(dest, src, mt.size) # copy raw bits
+
+proc genericSeqAssign(dest, src: Pointer, mt: PNimType) {.compilerProc.} =
+  genericAssign(dest, addr(src), mt)
+
+proc genericAssignOpenArray(dest, src: pointer, len: int,
+                            mt: PNimType) {.compilerproc.} =
+  var
+    d = cast[TAddress](dest)
+    s = cast[TAddress](src)
+  for i in 0..len-1:
+    genericAssign(cast[pointer](d +% i*% mt.base.size),
+                  cast[pointer](s +% i*% mt.base.size), mt.base)
+
+proc objectInit(dest: Pointer, typ: PNimType) {.compilerProc.}
+proc objectInitAux(dest: Pointer, n: ptr TNimNode) =
+  var d = cast[TAddress](dest)
+  case n.kind
+  of nkNone: assert(false)
+  of nkSLot: objectInit(cast[pointer](d +% n.offset), n.typ)
+  of nkList: 
+    for i in 0..n.len-1:
+      objectInitAux(dest, n.sons[i])
+  of nkCase: 
+    var m = selectBranch(dest, n)
+    if m != nil: objectInitAux(dest, m)   
+
+proc objectInit(dest: Pointer, typ: PNimType) =
+  # the generic init proc that takes care of initialization of complex
+  # objects on the stack or heap
+  var d = cast[TAddress](dest)
+  case typ.kind
+  of tyObject:
+    # iterate over any structural type
+    # here we have to init the type field:
+    var pint = cast[ptr PNimType](dest)
+    pint^ = typ
+    objectInitAux(dest, typ.node)
+  of tyRecord:
+    objectInitAux(dest, typ.node)
+  of tyArray, tyArrayConstr:
+    for i in 0..(typ.size div typ.base.size)-1:
+      objectInit(cast[pointer](d +% i * typ.base.size), typ.base)
+  else: nil # nothing to do