summary refs log tree commit diff stats
path: root/compiler/semasgn.nim
diff options
context:
space:
mode:
Diffstat (limited to 'compiler/semasgn.nim')
-rw-r--r--compiler/semasgn.nim341
1 files changed, 214 insertions, 127 deletions
diff --git a/compiler/semasgn.nim b/compiler/semasgn.nim
index 483d36bf3..a1e209263 100644
--- a/compiler/semasgn.nim
+++ b/compiler/semasgn.nim
@@ -1,13 +1,14 @@
 #
 #
 #           The Nim Compiler
-#        (c) Copyright 2014 Andreas Rumpf
+#        (c) Copyright 2015 Andreas Rumpf
 #
 #    See the file "copying.txt", included in this
 #    distribution, for details about the copyright.
 #
 
-## This module implements lifting for assignments and ``deepCopy``.
+## This module implements lifting for assignments. Later versions of this code
+## will be able to also lift ``=deepCopy`` and ``=destroy``.
 
 # included from sem.nim
 
@@ -15,98 +16,75 @@ type
   TLiftCtx = object
     c: PContext
     info: TLineInfo # for construction
-    result: PNode
     kind: TTypeAttachedOp
+    fn: PSym
+    asgnForType: PType
+    recurse: bool
 
-type
-  TFieldInstCtx = object  # either 'tup[i]' or 'field' is valid
-    tupleType: PType      # if != nil we're traversing a tuple
-    tupleIndex: int
-    field: PSym
-    replaceByFieldName: bool
+proc liftBodyAux(c: var TLiftCtx; t: PType; body, x, y: PNode)
+proc liftBody(c: PContext; typ: PType; info: TLineInfo): PSym
+
+proc at(a, i: PNode, elemType: PType): PNode =
+  result = newNodeI(nkBracketExpr, a.info, 2)
+  result.sons[0] = a
+  result.sons[1] = i
+  result.typ = elemType
+
+proc liftBodyTup(c: var TLiftCtx; t: PType; body, x, y: PNode) =
+  for i in 0 .. <t.len:
+    let lit = lowerings.newIntLit(i)
+    liftBodyAux(c, t.sons[i], body, x.at(lit, t.sons[i]), y.at(lit, t.sons[i]))
+
+proc dotField(x: PNode, f: PSym): PNode =
+  result = newNodeI(nkDotExpr, x.info, 2)
+  result.sons[0] = x
+  result.sons[1] = newSymNode(f, x.info)
+  result.typ = f.typ
 
-proc instFieldLoopBody(c: TFieldInstCtx, n: PNode, forLoop: PNode): PNode =
+proc liftBodyObj(c: var TLiftCtx; n, body, x, y: PNode) =
   case n.kind
-  of nkEmpty..pred(nkIdent), succ(nkIdent)..nkNilLit: result = n
-  of nkIdent:
-    result = n
-    var L = sonsLen(forLoop)
-    if c.replaceByFieldName:
-      if n.ident.id == forLoop[0].ident.id:
-        let fieldName = if c.tupleType.isNil: c.field.name.s
-                        elif c.tupleType.n.isNil: "Field" & $c.tupleIndex
-                        else: c.tupleType.n.sons[c.tupleIndex].sym.name.s
-        result = newStrNode(nkStrLit, fieldName)
-        return
-    # other fields:
-    for i in ord(c.replaceByFieldName)..L-3:
-      if n.ident.id == forLoop[i].ident.id:
-        var call = forLoop.sons[L-2]
-        var tupl = call.sons[i+1-ord(c.replaceByFieldName)]
-        if c.field.isNil:
-          result = newNodeI(nkBracketExpr, n.info)
-          result.add(tupl)
-          result.add(newIntNode(nkIntLit, c.tupleIndex))
-        else:
-          result = newNodeI(nkDotExpr, n.info)
-          result.add(tupl)
-          result.add(newSymNode(c.field, n.info))
-        break
-  else:
-    if n.kind == nkContinueStmt:
-      localError(n.info, errGenerated,
-                 "'continue' not supported in a 'fields' loop")
-    result = copyNode(n)
-    newSons(result, sonsLen(n))
-    for i in countup(0, sonsLen(n)-1):
-      result.sons[i] = instFieldLoopBody(c, n.sons[i], forLoop)
-
-proc liftBodyObj(c: TLiftCtx; typ, x, y: PNode) =
-  case typ.kind
   of nkSym:
-    var fc: TFieldInstCtx  # either 'tup[i]' or 'field' is valid
-    fc.field = typ.sym
-    fc.replaceByFieldName = c.m == mFieldPairs
-    openScope(c.c)
-    inc c.c.inUnrolledContext
-    let body = instFieldLoopBody(fc, lastSon(forLoop), forLoop)
-    father.add(semStmt(c.c, body))
-    dec c.c.inUnrolledContext
-    closeScope(c.c)
+    let f = n.sym
+    liftBodyAux(c, f.typ, body, x.dotField(f), y.dotField(f))
   of nkNilLit: discard
   of nkRecCase:
-    let L = forLoop.len
-    let call = forLoop.sons[L-2]
-    if call.len > 2:
-      localError(forLoop.info, errGenerated, 
-                 "parallel 'fields' iterator does not work for 'case' objects")
-      return
-    # iterate over the selector:
-    asgnForObjectFields(c, typ[0], forLoop, father)
+    # copy the selector:
+    liftBodyObj(c, n[0], body, x, y)
     # we need to generate a case statement:
     var caseStmt = newNodeI(nkCaseStmt, c.info)
+    # XXX generate 'if' that checks same branches
     # generate selector:
-    var access = newNodeI(nkDotExpr, forLoop.info, 2)
-    access.sons[0] = call.sons[1]
-    access.sons[1] = newSymNode(typ.sons[0].sym, forLoop.info)
-    caseStmt.add(semExprWithType(c.c, access))
+    var access = dotField(x, n[0].sym)
+    caseStmt.add(access)
     # copy the branches over, but replace the fields with the for loop body:
-    for i in 1 .. <typ.len:
-      var branch = copyTree(typ[i])
+    for i in 1 .. <n.len:
+      var branch = copyTree(n[i])
       let L = branch.len
-      branch.sons[L-1] = newNodeI(nkStmtList, forLoop.info)
-      semForObjectFields(c, typ[i].lastSon, forLoop, branch[L-1])
+      branch.sons[L-1] = newNodeI(nkStmtList, c.info)
+
+      liftBodyObj(c, n[i].lastSon, branch.sons[L-1], x, y)
       caseStmt.add(branch)
-    father.add(caseStmt)
+    body.add(caseStmt)
+    localError(c.info, "cannot lift assignment operator to 'case' object")
   of nkRecList:
-    for t in items(typ): liftBodyObj(c, t, x, y)
+    for t in items(n): liftBodyObj(c, t, body, x, y)
+  else:
+    illFormedAstLocal(n)
+
+proc genAddr(c: PContext; x: PNode): PNode =
+  if x.kind == nkHiddenDeref:
+    checkSonsLen(x, 1)
+    result = x.sons[0]
   else:
-    illFormedAst(typ)
+    result = newNodeIT(nkHiddenAddr, x.info, makeVarType(c, x.typ))
+    addSon(result, x)
 
-proc newAsgnCall(op: PSym; x, y: PNode): PNode =
+proc newAsgnCall(c: PContext; op: PSym; x, y: PNode): PNode =
+  if sfError in op.flags:
+    localError(x.info, errWrongSymbolX, op.name.s)
   result = newNodeI(nkCall, x.info)
-  result.add(newSymNode(op))
-  result.add x
+  result.add newSymNode(op)
+  result.add genAddr(c, x)
   result.add y
 
 proc newAsgnStmt(le, ri: PNode): PNode =
@@ -117,81 +95,190 @@ proc newAsgnStmt(le, ri: PNode): PNode =
 proc newDestructorCall(op: PSym; x: PNode): PNode =
   result = newNodeIT(nkCall, x.info, op.typ.sons[0])
   result.add(newSymNode(op))
-  result.add x  
+  result.add x
 
 proc newDeepCopyCall(op: PSym; x, y: PNode): PNode =
   result = newAsgnStmt(x, newDestructorCall(op, y))
 
-proc considerOverloadedOp(c: TLiftCtx; t: PType; x, y: PNode): bool =
-  let op = t.attachedOps[c.kind]
-  if op != nil:
-    markUsed(c.info, op)
-    styleCheckUse(c.info, op)
-    case c.kind
-    of attachedDestructor:
-      c.result.add newDestructorCall(op, x)
-    of attachedAsgn:
-      c.result.add newAsgnCall(op, x, y)
-    of attachedDeepCopy:
-      c.result.add newDeepCopyCall(op, x, y)
-    result = true
-
-proc defaultOp(c: TLiftCtx; t: PType; x, y: PNode) =
+proc considerOverloadedOp(c: var TLiftCtx; t: PType; body, x, y: PNode): bool =
+  case c.kind
+  of attachedDestructor:
+    let op = t.destructor
+    if op != nil:
+      markUsed(c.info, op)
+      styleCheckUse(c.info, op)
+      body.add newDestructorCall(op, x)
+      result = true
+  of attachedAsgn:
+    if tfHasAsgn in t.flags:
+      var op: PSym
+      if sameType(t, c.asgnForType):
+        # generate recursive call:
+        if c.recurse:
+          op = c.fn
+        else:
+          c.recurse = true
+          return false
+      else:
+        op = t.assignment
+        if op == nil:
+          op = liftBody(c.c, t, c.info)
+      markUsed(c.info, op)
+      styleCheckUse(c.info, op)
+      body.add newAsgnCall(c.c, op, x, y)
+      result = true
+  of attachedDeepCopy:
+    let op = t.deepCopy
+    if op != nil:
+      markUsed(c.info, op)
+      styleCheckUse(c.info, op)
+      body.add newDeepCopyCall(op, x, y)
+      result = true
+
+proc defaultOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   if c.kind != attachedDestructor:
-    c.result.add newAsgnStmt(x, y)
-
-proc liftBodyAux(c: TLiftCtx; t: PType; x, y: PNode) =
-  const hasAttachedOp: array[TTypeAttachedOp, TTypeIter] = [
-    (proc (t: PType, closure: PObject): bool =
-       t.attachedOp[attachedDestructor] != nil),
-    (proc (t: PType, closure: PObject): bool =
-       t.attachedOp[attachedAsgn] != nil),
-    (proc (t: PType, closure: PObject): bool =
-       t.attachedOp[attachedDeepCopy] != nil)]
+    body.add newAsgnStmt(x, y)
+
+proc addVar(father, v, value: PNode) =
+  var vpart = newNodeI(nkIdentDefs, v.info, 3)
+  vpart.sons[0] = v
+  vpart.sons[1] = ast.emptyNode
+  vpart.sons[2] = value
+  addSon(father, vpart)
+
+proc declareCounter(c: var TLiftCtx; body: PNode; first: BiggestInt): PNode =
+  var temp = newSym(skTemp, getIdent(lowerings.genPrefix), c.fn, c.info)
+  temp.typ = getSysType(tyInt)
+  incl(temp.flags, sfFromGeneric)
+
+  var v = newNodeI(nkVarSection, c.info)
+  result = newSymNode(temp)
+  v.addVar(result, lowerings.newIntLit(first))
+  body.add v
+
+proc genBuiltin(magic: TMagic; name: string; i: PNode): PNode =
+  result = newNodeI(nkCall, i.info)
+  result.add createMagic(name, magic).newSymNode
+  result.add i
+
+proc genWhileLoop(c: var TLiftCtx; i, dest: PNode): PNode =
+  result = newNodeI(nkWhileStmt, c.info, 2)
+  let cmp = genBuiltin(mLeI, "<=", i)
+  cmp.add genHigh(dest)
+  cmp.typ = getSysType(tyBool)
+  result.sons[0] = cmp
+  result.sons[1] = newNodeI(nkStmtList, c.info)
+
+proc addIncStmt(body, i: PNode) =
+  let incCall = genBuiltin(mInc, "inc", i)
+  incCall.add lowerings.newIntLit(1)
+  body.add incCall
+
+proc newSeqCall(c: PContext; x, y: PNode): PNode =
+  # don't call genAddr(c, x) here:
+  result = genBuiltin(mNewSeq, "newSeq", x)
+  let lenCall = genBuiltin(mLengthSeq, "len", y)
+  lenCall.typ = getSysType(tyInt)
+  result.add lenCall
+
+proc liftBodyAux(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   case t.kind
   of tyNone, tyEmpty: discard
-  of tyPointer, tySet, tyBool, tyChar, tyEnum, tyInt..tyUInt64, tyCString:
-    defaultOp(c, t, x, y)
-  of tyPtr, tyString:
-    if not considerOverloadedOp(c, t, x, y):
-      defaultOp(c, t, x, y)
+  of tyPointer, tySet, tyBool, tyChar, tyEnum, tyInt..tyUInt64, tyCString,
+      tyPtr, tyString, tyRef:
+    defaultOp(c, t, body, x, y)
   of tyArrayConstr, tyArray, tySequence:
-    if iterOverType(lastSon(t), hasAttachedOp[c.kind], nil):
-      # generate loop and call the attached Op:
-      
+    if tfHasAsgn in t.flags:
+      if t.kind == tySequence:
+        # XXX add 'nil' handling here
+        body.add newSeqCall(c.c, x, y)
+      let i = declareCounter(c, body, firstOrd(t))
+      let whileLoop = genWhileLoop(c, i, x)
+      let elemType = t.lastSon
+      liftBodyAux(c, elemType, whileLoop.sons[1], x.at(i, elemType),
+                                                  y.at(i, elemType))
+      addIncStmt(whileLoop.sons[1], i)
+      body.add whileLoop
     else:
-      defaultOp(c, t, x, y)
-  of tyObject:
-    liftBodyObj(c, t.n, x, y)
+      defaultOp(c, t, body, x, y)
+  of tyObject, tyDistinct:
+    if not considerOverloadedOp(c, t, body, x, y):
+      if t.sons[0] != nil: liftBodyAux(c, t.sons[0], body, x, y)
+      if t.kind == tyObject: liftBodyObj(c, t.n, body, x, y)
   of tyTuple:
-    liftBodyTup(c, t, x, y)
-  of tyRef:
-    # we MUST not check for acyclic here as a DAG might still share nodes:
-    
+    liftBodyTup(c, t, body, x, y)
   of tyProc:
     if t.callConv != ccClosure or c.kind != attachedDeepCopy:
-      defaultOp(c, t, x, y)
+      defaultOp(c, t, body, x, y)
     else:
       # a big problem is that we don't know the enviroment's type here, so we
       # have to go through some indirection; we delegate this to the codegen:
-      call = newNodeI(nkCall, n.info, 2)
+      let call = newNodeI(nkCall, c.info, 2)
       call.typ = t
       call.sons[0] = newSymNode(createMagic("deepCopy", mDeepCopy))
       call.sons[1] = y
-      c.result.add newAsgnStmt(x, call)
+      body.add newAsgnStmt(x, call)
   of tyVarargs, tyOpenArray:
     localError(c.info, errGenerated, "cannot copy openArray")
   of tyFromExpr, tyIter, tyProxy, tyBuiltInTypeClass, tyUserTypeClass,
      tyUserTypeClassInst, tyCompositeTypeClass, tyAnd, tyOr, tyNot, tyAnything,
      tyMutable, tyGenericParam, tyGenericBody, tyNil, tyExpr, tyStmt,
-     tyTypeDesc, tyGenericInvokation, tyBigNum, tyConst, tyForward:
+     tyTypeDesc, tyGenericInvocation, tyBigNum, tyConst, tyForward:
     internalError(c.info, "assignment requested for type: " & typeToString(t))
-  of tyDistinct, tyOrdinal, tyRange,
+  of tyOrdinal, tyRange,
      tyGenericInst, tyFieldAccessor, tyStatic, tyVar:
-    liftBodyAux(c, lastSon(t))
+    liftBodyAux(c, lastSon(t), body, x, y)
+
+proc newProcType(info: TLineInfo; owner: PSym): PType =
+  result = newType(tyProc, owner)
+  result.n = newNodeI(nkFormalParams, info)
+  rawAddSon(result, nil) # return type
+  # result.n[0] used to be `nkType`, but now it's `nkEffectList` because
+  # the effects are now stored in there too ... this is a bit hacky, but as
+  # usual we desperately try to save memory:
+  addSon(result.n, newNodeI(nkEffectList, info))
+
+proc addParam(procType: PType; param: PSym) =
+  param.position = procType.len-1
+  addSon(procType.n, newSymNode(param))
+  rawAddSon(procType, param.typ)
 
-proc liftBody(c: PContext; typ: PType; info: TLineInfo): PNode =
+proc liftBody(c: PContext; typ: PType; info: TLineInfo): PSym =
   var a: TLiftCtx
   a.info = info
-  a.result = newNodeI(nkStmtList, info)
-  liftBodyAux(a, typ)
+  let body = newNodeI(nkStmtList, info)
+  result = newSym(skProc, getIdent":lifted=", typ.owner, info)
+  a.fn = result
+  a.asgnForType = typ
+
+  let dest = newSym(skParam, getIdent"dest", result, info)
+  let src = newSym(skParam, getIdent"src", result, info)
+  dest.typ = makeVarType(c, typ)
+  src.typ = typ
+
+  result.typ = newProcType(info, typ.owner)
+  result.typ.addParam dest
+  result.typ.addParam src
+
+  liftBodyAux(a, typ, body, newSymNode(dest).newDeref, newSymNode(src))
+
+  var n = newNodeI(nkProcDef, info, bodyPos+1)
+  for i in 0 .. < n.len: n.sons[i] = emptyNode
+  n.sons[namePos] = newSymNode(result)
+  n.sons[paramsPos] = result.typ.n
+  n.sons[bodyPos] = body
+  result.ast = n
+
+  # register late as recursion is handled differently
+  typ.assignment = result
+  #echo "Produced this ", n
+
+proc getAsgnOrLiftBody(c: PContext; typ: PType; info: TLineInfo): PSym =
+  let t = typ.skipTypes({tyGenericInst, tyVar})
+  result = t.assignment
+  if result.isNil:
+    result = liftBody(c, t, info)
+
+proc overloadedAsgn(c: PContext; dest, src: PNode): PNode =
+  let a = getAsgnOrLiftBody(c, dest.typ, dest.info)
+  result = newAsgnCall(c, a, dest, src)