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Fix #16437 (#17277)

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* Fix #16437

* Fix

* Small cleanup
This commit is contained in:
Clyybber 2021-03-06 22:35:02 +01:00 • committed by GitHub
commit 38d82795da
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5 changed files with 75 additions and 36 deletions
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42
compiler/injectdestructors.nim
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@ -222,14 +222,14 @@ proc initialized(code: ControlFlowGraph; pc: int,
inc pc
return pc
proc isCursor(n: PNode; c: Con): bool =
proc isCursor(n: PNode): bool =
case n.kind
of nkSym:
sfCursor in n.sym.flags
of nkDotExpr:
isCursor(n[1], c)
isCursor(n[1])
of nkCheckedFieldExpr:
isCursor(n[0], c)
isCursor(n[0])
else:
false
@ -528,23 +528,19 @@ proc cycleCheck(n: PNode; c: var Con) =
message(c.graph.config, n.info, warnCycleCreated, msg)
break
proc pVarTopLevel(v: PNode; c: var Con; s: var Scope; ri, res: PNode) =
proc pVarTopLevel(v: PNode; c: var Con; s: var Scope; res: PNode) =
# move the variable declaration to the top of the frame:
s.vars.add v.sym
if isUnpackedTuple(v):
if c.inLoop > 0:
# unpacked tuple needs reset at every loop iteration
res.add newTree(nkFastAsgn, v, genDefaultCall(v.typ, c, v.info))
elif sfThread notin v.sym.flags:
elif sfThread notin v.sym.flags and sfCursor notin v.sym.flags:
# do not destroy thread vars for now at all for consistency.
if sfGlobal in v.sym.flags and s.parent == nil: #XXX: Rethink this logic (see tarcmisc.test2)
c.graph.globalDestructors.add c.genDestroy(v)
else:
s.final.add c.genDestroy(v)
if ri.kind == nkEmpty and c.inLoop > 0:
res.add moveOrCopy(v, genDefaultCall(v.typ, c, v.info), c, s, isDecl = true)
elif ri.kind != nkEmpty:
res.add moveOrCopy(v, ri, c, s, isDecl = true)
proc processScope(c: var Con; s: var Scope; ret: PNode): PNode =
result = newNodeI(nkStmtList, ret.info)
@ -744,7 +740,7 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode): PNode =
nkCallKinds + nkLiterals:
result = p(n, c, s, consumed)
elif ((n.kind == nkSym and isSinkParam(n.sym)) or isAnalysableFieldAccess(n, c.owner)) and
isLastRead(n, c) and not (n.kind == nkSym and isCursor(n, c)):
isLastRead(n, c) and not (n.kind == nkSym and isCursor(n)):
# Sinked params can be consumed only once. We need to reset the memory
# to disable the destructor which we have not elided
result = destructiveMoveVar(n, c, s)
@ -850,17 +846,16 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode): PNode =
if it.kind == nkVarTuple and hasDestructor(c, ri.typ):
let x = lowerTupleUnpacking(c.graph, it, c.idgen, c.owner)
result.add p(x, c, s, consumed)
elif it.kind == nkIdentDefs and hasDestructor(c, it[0].typ) and not isCursor(it[0], c):
elif it.kind == nkIdentDefs and hasDestructor(c, it[0].typ):
for j in 0..<it.len-2:
let v = it[j]
if v.kind == nkSym:
if sfCompileTime in v.sym.flags: continue
pVarTopLevel(v, c, s, ri, result)
else:
if ri.kind == nkEmpty and c.inLoop > 0:
ri = genDefaultCall(v.typ, c, v.info)
if ri.kind != nkEmpty:
result.add moveOrCopy(v, ri, c, s, isDecl = false)
pVarTopLevel(v, c, s, result)
if ri.kind != nkEmpty:
result.add moveOrCopy(v, ri, c, s, isDecl = v.kind == nkSym)
elif ri.kind == nkEmpty and c.inLoop > 0:
result.add moveOrCopy(v, genDefaultCall(v.typ, c, v.info), c, s, isDecl = v.kind == nkSym)
else: # keep the var but transform 'ri':
var v = copyNode(n)
var itCopy = copyNode(it)
@ -870,8 +865,7 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode): PNode =
v.add itCopy
result.add v
of nkAsgn, nkFastAsgn:
if hasDestructor(c, n[0].typ) and n[1].kind notin {nkProcDef, nkDo, nkLambda} and
not isCursor(n[0], c):
if hasDestructor(c, n[0].typ) and n[1].kind notin {nkProcDef, nkDo, nkLambda}:
if n[0].kind in {nkDotExpr, nkCheckedFieldExpr}:
cycleCheck(n, c)
assert n[1].kind notin {nkAsgn, nkFastAsgn}
@ -1003,6 +997,14 @@ proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope, isDecl = false): PNod
if sameLocation(dest, ri):
# rule (self-assignment-removal):
result = newNodeI(nkEmpty, dest.info)
elif isCursor(dest):
case ri.kind:
of nkStmtListExpr, nkBlockExpr, nkIfExpr, nkCaseStmt, nkTryStmt:
template process(child, s): untyped = moveOrCopy(dest, child, c, s, isDecl)
# We know the result will be a stmt so we use that fact to optimize
handleNestedTempl(ri, process, willProduceStmt = true)
else:
result = newTree(nkFastAsgn, dest, p(ri, c, s, normal))
else:
case ri.kind
of nkCallKinds:
@ -1038,7 +1040,7 @@ proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope, isDecl = false): PNod
let snk = c.genSink(dest, ri, isDecl)
result = newTree(nkStmtList, snk, c.genWasMoved(ri))
elif ri.sym.kind != skParam and ri.sym.owner == c.owner and
isLastRead(ri, c) and canBeMoved(c, dest.typ) and not isCursor(ri, c):
isLastRead(ri, c) and canBeMoved(c, dest.typ) and not isCursor(ri):
# Rule 3: `=sink`(x, z); wasMoved(z)
let snk = c.genSink(dest, ri, isDecl)
result = newTree(nkStmtList, snk, c.genWasMoved(ri))