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ARC: closure bugfixes (#12677)

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* ARC: closure bugfixes
* progress
* ARC closures: create =hooks for captured parameters
* ARC: always destroy constructions like tuples, arrays properly, even in edge cases
* fixes a regression
This commit is contained in:
Andreas Rumpf 2019-11-18 12:33:44 +01:00 • committed by GitHub
commit 5278cf80eb
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4 changed files with 72 additions and 16 deletions
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51
compiler/injectdestructors.nim
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@ -271,7 +271,7 @@ proc sinkParamIsLastReadCheck(c: var Con, s: PNode) =
localError(c.graph.config, c.otherRead.info, "sink parameter `" & $s.sym.name.s &
"` is already consumed at " & toFileLineCol(c. graph.config, s.info))
proc p(n: PNode; c: var Con): PNode
proc p(n: PNode; c: var Con; consumed = false): PNode
proc pArg(arg: PNode; c: var Con; isSink: bool): PNode
proc moveOrCopy(dest, ri: PNode; c: var Con): PNode
@ -366,6 +366,22 @@ template handleNested(n: untyped, processCall: untyped) =
result.add branch
else: assert(false)
proc ensureDestruction(arg: PNode; c: var Con): PNode =
# it can happen that we need to destroy expression contructors
# like [], (), closures explicitly in order to not leak them.
if arg.typ != nil and hasDestructor(arg.typ):
# produce temp creation for (fn, env). But we need to move 'env'?
# This was already done in the sink parameter handling logic.
result = newNodeIT(nkStmtListExpr, arg.info, arg.typ)
let tmp = getTemp(c, arg.typ, arg.info)
var sinkExpr = genSink(c, tmp, arg)
sinkExpr.add arg
result.add sinkExpr
result.add tmp
c.destroys.add genDestroy(c, tmp)
else:
result = arg
proc pArg(arg: PNode; c: var Con; isSink: bool): PNode =
if isSink:
if arg.kind in nkCallKinds:
@ -374,7 +390,7 @@ proc pArg(arg: PNode; c: var Con; isSink: bool): PNode =
result = copyNode(arg)
let parameters = arg[0].typ
let L = if parameters != nil: parameters.len else: 0
result.add arg[0]
result.add pArg(arg[0], c, isSink = false)
for i in 1..<arg.len:
result.add pArg(arg[i], c, i < L and isSinkTypeForParam(parameters[i]))
elif arg.containsConstSeq:
@ -392,6 +408,9 @@ proc pArg(arg: PNode; c: var Con; isSink: bool): PNode =
result[i][1] = pArg(arg[i][1], c, isSink = true)
else:
result[i] = pArg(arg[i], c, isSink = true)
#if arg.kind == nkClosure:
# result = handleClosureCall(result, c)
# Not required here because the nkClosure will be consumed!
elif arg.kind == nkSym and isSinkParam(arg.sym):
# Sinked params can be consumed only once. We need to reset the memory
# to disable the destructor which we have not elided
@ -442,7 +461,7 @@ proc isCursor(n: PNode): bool =
else:
result = false
proc p(n: PNode; c: var Con): PNode =
proc p(n: PNode; c: var Con; consumed = false): PNode =
case n.kind
of nkCallKinds:
let parameters = n[0].typ
@ -454,6 +473,8 @@ proc p(n: PNode; c: var Con): PNode =
if c.graph.config.selectedGC in {gcHooks, gcDestructors}:
let destroyOld = genDestroy(c, result[1])
result = newTree(nkStmtList, destroyOld, result)
else:
result[0] = pArg(result[0], c, isSink = false)
of nkDiscardStmt: # Small optimization
if n[0].kind != nkEmpty:
n[0] = pArg(n[0], c, false)
@ -464,12 +485,16 @@ proc p(n: PNode; c: var Con): PNode =
# everything that is passed to an array constructor is consumed,
# so these all act like 'sink' parameters:
result[i] = pArg(n[i], c, isSink = true)
if not consumed:
result = ensureDestruction(result, c)
of nkObjConstr:
result = copyTree(n)
for i in 1..<n.len:
# everything that is passed to an object constructor is consumed,
# so these all act like 'sink' parameters:
result[i][1] = pArg(n[i][1], c, isSink = true)
if not consumed:
result = ensureDestruction(result, c)
of nkTupleConstr, nkClosure:
result = copyTree(n)
for i in ord(n.kind == nkClosure)..<n.len:
@ -479,6 +504,8 @@ proc p(n: PNode; c: var Con): PNode =
result[i][1] = pArg(n[i][1], c, isSink = true)
else:
result[i] = pArg(n[i], c, isSink = true)
if not consumed:
result = ensureDestruction(result, c)
of nkVarSection, nkLetSection:
# transform; var x = y to var x; x op y where op is a move or copy
result = newNodeI(nkStmtList, n.info)
@ -556,11 +583,11 @@ proc p(n: PNode; c: var Con): PNode =
result = copyTree(n)
result[1][0] = p(result[1][0], c)
of nkStmtList, nkStmtListExpr, nkBlockStmt, nkBlockExpr, nkIfStmt, nkIfExpr, nkCaseStmt:
handleNested(n): p(node, c)
handleNested(n): p(node, c, consumed)
else:
result = shallowCopy(n)
for i in 0..<n.len:
result[i] = p(n[i], c)
result[i] = p(n[i], c, consumed)
proc moveOrCopy(dest, ri: PNode; c: var Con): PNode =
# unfortunately, this needs to be kept consistent with the cases
@ -571,12 +598,12 @@ proc moveOrCopy(dest, ri: PNode; c: var Con): PNode =
case ri.kind
of nkCallKinds:
result = genSink(c, dest, ri)
result.add p(ri, c)
result.add p(ri, c, consumed = true)
of nkBracketExpr:
if ri[0].kind == nkSym and isUnpackedTuple(ri[0].sym):
# unpacking of tuple: move out the elements
result = genSink(c, dest, ri)
result.add p(ri, c)
result.add p(ri, c, consumed = true)
elif isAnalysableFieldAccess(ri, c.owner) and isLastRead(ri, c):
# Rule 3: `=sink`(x, z); wasMoved(z)
var snk = genSink(c, dest, ri)
@ -584,17 +611,17 @@ proc moveOrCopy(dest, ri: PNode; c: var Con): PNode =
result = newTree(nkStmtList, snk, genWasMoved(ri, c))
else:
result = genCopy(c, dest, ri)
result.add p(ri, c)
result.add p(ri, c, consumed = true)
of nkBracket:
# array constructor
if ri.len > 0 and isDangerousSeq(ri.typ):
result = genCopy(c, dest, ri)
else:
result = genSink(c, dest, ri)
result.add p(ri, c)
result.add p(ri, c, consumed = true)
of nkObjConstr, nkTupleConstr, nkClosure, nkCharLit..nkNilLit:
result = genSink(c, dest, ri)
result.add p(ri, c)
result.add p(ri, c, consumed = true)
of nkSym:
if isSinkParam(ri.sym):
# Rule 3: `=sink`(x, z); wasMoved(z)
@ -610,7 +637,7 @@ proc moveOrCopy(dest, ri: PNode; c: var Con): PNode =
result = newTree(nkStmtList, snk, genWasMoved(ri, c))
else:
result = genCopy(c, dest, ri)
result.add p(ri, c)
result.add p(ri, c, consumed = true)
of nkHiddenSubConv, nkHiddenStdConv, nkConv:
result = moveOrCopy(dest, ri[1], c)
if not sameType(ri.typ, ri[1].typ):
@ -633,7 +660,7 @@ proc moveOrCopy(dest, ri: PNode; c: var Con): PNode =
result = newTree(nkStmtList, snk, genWasMoved(ri, c))
else:
result = genCopy(c, dest, ri)
result.add p(ri, c)
result.add p(ri, c, consumed = true)
proc computeUninit(c: var Con) =
if not c.uninitComputed: