diff options
Diffstat (limited to 'compiler/injectdestructors.nim')
| -rw-r--r-- | compiler/injectdestructors.nim | 54 |
1 files changed, 28 insertions, 26 deletions
diff --git a/compiler/injectdestructors.nim b/compiler/injectdestructors.nim index 98cfb4743..556d098f4 100644 --- a/compiler/injectdestructors.nim +++ b/compiler/injectdestructors.nim @@ -13,18 +13,11 @@ ## See doc/destructors.rst for a spec of the implemented rewrite rules -## XXX Optimization to implement: if a local variable is only assigned -## string literals as in ``let x = conf: "foo" else: "bar"`` do not -## produce a destructor call for ``x``. The address of ``x`` must also -## not have been taken. ``x = "abc"; x.add(...)`` - -# Todo: -# - eliminate 'wasMoved(x); destroy(x)' pairs as a post processing step. - import - intsets, ast, astalgo, msgs, renderer, magicsys, types, idents, + intsets, strtabs, ast, astalgo, msgs, renderer, magicsys, types, idents, strutils, options, dfa, lowerings, tables, modulegraphs, msgs, - lineinfos, parampatterns, sighashes, liftdestructors + lineinfos, parampatterns, sighashes, liftdestructors, optimizer, + cursor_inference from trees import exprStructuralEquivalent, getRoot @@ -42,6 +35,7 @@ type Con = object owner: PSym g: ControlFlowGraph + cursors: IntSet graph: ModuleGraph otherRead: PNode inLoop, inSpawn: int @@ -155,6 +149,17 @@ proc isLastRead(location: PNode; cfg: ControlFlowGraph; otherRead: var PNode; pc pc = min(variantA, variantB) return pc +proc isCursor(n: PNode; c: Con): bool = + case n.kind + of nkSym: + result = sfCursor in n.sym.flags or c.cursors.contains(n.sym.id) + of nkDotExpr: + result = sfCursor in n[1].sym.flags + of nkCheckedFieldExpr: + result = isCursor(n[0], c) + else: + result = false + proc isLastRead(n: PNode; c: var Con): bool = # first we need to search for the instruction that belongs to 'n': var instr = -1 @@ -486,17 +491,6 @@ proc ensureDestruction(arg, orig: PNode; c: var Con; s: var Scope): PNode = else: result = arg -proc isCursor(n: PNode): bool = - case n.kind - of nkSym: - result = sfCursor in n.sym.flags - of nkDotExpr: - result = sfCursor in n[1].sym.flags - of nkCheckedFieldExpr: - result = isCursor(n[0]) - else: - result = false - proc cycleCheck(n: PNode; c: var Con) = if c.graph.config.selectedGC != gcArc: return var value = n[1] @@ -727,7 +721,8 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode): PNode = elif n.kind in {nkBracket, nkObjConstr, nkTupleConstr, nkClosure, nkNilLit} + 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): + 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)): # 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) @@ -830,7 +825,7 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode): PNode = if it.kind == nkVarTuple and hasDestructor(ri.typ): let x = lowerTupleUnpacking(c.graph, it, c.owner) result.add p(x, c, s, consumed) - elif it.kind == nkIdentDefs and hasDestructor(it[0].typ) and not isCursor(it[0]): + elif it.kind == nkIdentDefs and hasDestructor(it[0].typ) and not isCursor(it[0], c): for j in 0..<it.len-2: let v = it[j] if v.kind == nkSym: @@ -851,7 +846,7 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode): PNode = result.add v of nkAsgn, nkFastAsgn: if hasDestructor(n[0].typ) and n[1].kind notin {nkProcDef, nkDo, nkLambda} and - not isCursor(n[0]): + not isCursor(n[0], c): # rule (self-assignment-removal): if n[1].kind == nkSym and n[0].kind == nkSym and n[0].sym == n[1].sym: result = newNodeI(nkEmpty, n.info) @@ -988,7 +983,7 @@ 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): + isLastRead(ri, c) and canBeMoved(c, dest.typ) and not isCursor(ri, c): # Rule 3: `=sink`(x, z); wasMoved(z) let snk = c.genSink(dest, ri, isDecl) result = newTree(nkStmtList, snk, c.genWasMoved(ri)) @@ -1048,6 +1043,8 @@ proc injectDestructorCalls*(g: ModuleGraph; owner: PSym; n: PNode): PNode = echoCfg(c.g) echo n + c.cursors = computeCursors(n, g.config) + var scope: Scope let body = p(n, c, scope, normal) @@ -1059,7 +1056,12 @@ proc injectDestructorCalls*(g: ModuleGraph; owner: PSym; n: PNode): PNode = scope.final.add c.genDestroy(params[i]) #if optNimV2 in c.graph.config.globalOptions: # injectDefaultCalls(n, c) - result = processScope(c, scope, body) + result = optimize processScope(c, scope, body) dbg: echo ">---------transformed-to--------->" echo renderTree(result, {renderIds}) + + if g.config.arcToExpand.hasKey(owner.name.s): + echo "--expandArc: ", owner.name.s + echo renderTree(result, {renderIr}) + echo "-- end of expandArc ------------------------" |