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somewhat working closures

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This commit is contained in:
Araq 2012-06-19 22:37:00 +02:00
commit f191059e56
8 changed files with 95 additions and 33 deletions
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52
compiler/lambdalifting.nim
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@ -218,8 +218,29 @@ proc isInnerProc(s, outerProc: PSym): bool {.inline.} =
s.owner == outerProc and not isGenericRoutine(s)
#s.typ.callConv == ccClosure
proc addClosureParam(i: PInnerContext, e: PEnv) =
var cp = newSym(skParam, getIdent(paramname), i.fn)
cp.info = i.fn.info
incl(cp.flags, sfFromGeneric)
cp.typ = newType(tyRef, i.fn)
addSon(cp.typ, e.tup)
i.closureParam = cp
addHiddenParam(i.fn, i.closureParam)
#echo "closure param added for ", i.fn.name.s, " ", i.fn.id
proc dummyClosureParam(o: POuterContext, i: PInnerContext) =
var e = o.currentEnv
if IdTableGet(o.lambdasToEnv, i.fn) == nil:
IdTablePut(o.lambdasToEnv, i.fn, e)
if i.closureParam == nil: addClosureParam(i, e)
proc captureVar(o: POuterContext, i: PInnerContext, local: PSym,
info: TLineInfo) =
# for inlined variables the owner is still wrong, so it can happen that it's
# not a captured variable at all ... *sigh*
var it = PEnv(IdTableGet(o.localsToEnv, local))
if it == nil: return
# we need to remember which inner most closure belongs to this lambda:
var e = o.currentEnv
if IdTableGet(o.lambdasToEnv, i.fn) == nil:
@ -227,19 +248,10 @@ proc captureVar(o: POuterContext, i: PInnerContext, local: PSym,
# variable already captured:
if IdNodeTableGet(i.localsToAccess, local) != nil: return
if i.closureParam == nil:
var cp = newSym(skParam, getIdent(paramname), i.fn)
cp.info = i.fn.info
incl(cp.flags, sfFromGeneric)
cp.typ = newType(tyRef, i.fn)
addSon(cp.typ, e.tup)
i.closureParam = cp
addHiddenParam(i.fn, i.closureParam)
if i.closureParam == nil: addClosureParam(i, e)
# check which environment `local` belongs to:
var access = newSymNode(i.closureParam)
var it = PEnv(IdTableGet(o.localsToEnv, local))
assert it != nil
addCapturedVar(it, local)
if it == e:
# common case: local directly in current environment:
@ -325,6 +337,9 @@ proc searchForInnerProcs(o: POuterContext, n: PNode) =
var inner = newInnerContext(n.sym)
let body = n.sym.getBody
gatherVars(o, inner, body)
# dummy closure param needed?
if inner.closureParam == nil and n.sym.typ.callConv == ccClosure:
dummyClosureParam(o, inner)
let ti = transformInnerProc(o, inner, body)
if ti != nil: n.sym.ast.sons[bodyPos] = ti
of nkLambdaKinds:
@ -425,9 +440,19 @@ proc transformOuterProc(o: POuterContext, n: PNode): PNode =
if closure != nil:
# we need to replace the lambda with '(lambda, env)':
let a = closure.closure
assert a != nil
return makeClosure(local, a, n.info)
if a != nil:
return makeClosure(local, a, n.info)
else:
# can happen for dummy closures:
var scope = closure.attachedNode
assert scope.kind == nkStmtList
if scope.sons[0].kind == nkEmpty:
# change the empty node to contain the closure construction:
scope.sons[0] = generateClosureCreation(o, closure)
let x = closure.closure
assert x != nil
return makeClosure(local, x, n.info)
if not contains(o.capturedVars, local.id): return
var env = PEnv(IdTableGet(o.localsToEnv, local))
if env == nil: return
@ -474,5 +499,6 @@ proc liftLambdas(fn: PSym, body: PNode): PNode =
proc liftLambdas*(n: PNode): PNode =
assert n.kind in procDefs
if gCmd == cmdCompileToEcmaScript: return n
var s = n.sons[namePos].sym
result = liftLambdas(s, s.getBody)