/** Prints the given <code>JimpleBody</code> to the specified <code>PrintWriter</code>. */ private void printLocalsInBody(Body body, UnitPrinter up) { // Print out local variables { Map typeToLocals = new DeterministicHashMap(body.getLocalCount() * 2 + 1, 0.7f); // Collect locals { Iterator localIt = body.getLocals().iterator(); while (localIt.hasNext()) { Local local = (Local) localIt.next(); List localList; Type t = local.getType(); if (typeToLocals.containsKey(t)) localList = (List) typeToLocals.get(t); else { localList = new ArrayList(); typeToLocals.put(t, localList); } localList.add(local); } } // Print locals { Iterator typeIt = typeToLocals.keySet().iterator(); while (typeIt.hasNext()) { Type type = (Type) typeIt.next(); List localList = (List) typeToLocals.get(type); Object[] locals = localList.toArray(); up.type(type); up.literal(" "); for (int k = 0; k < locals.length; k++) { if (k != 0) up.literal(", "); up.local((Local) locals[k]); } up.literal(";"); up.newline(); } } if (!typeToLocals.isEmpty()) { up.newline(); } } }
private static boolean internalAggregate( StmtBody body, Map<ValueBox, Zone> boxToZone, boolean onlyStackVars) { LocalUses localUses; LocalDefs localDefs; ExceptionalUnitGraph graph; boolean hadAggregation = false; Chain<Unit> units = body.getUnits(); graph = new ExceptionalUnitGraph(body); localDefs = new SmartLocalDefs(graph, new SimpleLiveLocals(graph)); localUses = new SimpleLocalUses(graph, localDefs); List<Unit> unitList = new PseudoTopologicalOrderer<Unit>().newList(graph, false); for (Unit u : unitList) { if (!(u instanceof AssignStmt)) continue; AssignStmt s = (AssignStmt) u; Value lhs = s.getLeftOp(); if (!(lhs instanceof Local)) continue; Local lhsLocal = (Local) lhs; if (onlyStackVars && !lhsLocal.getName().startsWith("$")) continue; List<UnitValueBoxPair> lu = localUses.getUsesOf(s); if (lu.size() != 1) continue; UnitValueBoxPair usepair = lu.get(0); Unit use = usepair.unit; ValueBox useBox = usepair.valueBox; List<Unit> ld = localDefs.getDefsOfAt(lhsLocal, use); if (ld.size() != 1) continue; // Check to make sure aggregation pair in the same zone if (boxToZone.get(s.getRightOpBox()) != boxToZone.get(usepair.valueBox)) { continue; } /* we need to check the path between def and use */ /* to see if there are any intervening re-defs of RHS */ /* in fact, we should check that this path is unique. */ /* if the RHS uses only locals, then we know what to do; if RHS has a method invocation f(a, b, c) or field access, we must ban field writes, other method calls and (as usual) writes to a, b, c. */ boolean cantAggr = false; boolean propagatingInvokeExpr = false; boolean propagatingFieldRef = false; boolean propagatingArrayRef = false; ArrayList<FieldRef> fieldRefList = new ArrayList<FieldRef>(); LinkedList<Value> localsUsed = new LinkedList<Value>(); for (ValueBox vb : s.getUseBoxes()) { Value v = vb.getValue(); if (v instanceof Local) localsUsed.add(v); else if (v instanceof InvokeExpr) propagatingInvokeExpr = true; else if (v instanceof ArrayRef) propagatingArrayRef = true; else if (v instanceof FieldRef) { propagatingFieldRef = true; fieldRefList.add((FieldRef) v); } } // look for a path from s to use in graph. // only look in an extended basic block, though. List<Unit> path = graph.getExtendedBasicBlockPathBetween(s, use); if (path == null) continue; Iterator<Unit> pathIt = path.iterator(); // skip s. if (pathIt.hasNext()) pathIt.next(); while (pathIt.hasNext() && !cantAggr) { Stmt between = (Stmt) (pathIt.next()); if (between != use) { // Check for killing definitions for (ValueBox vb : between.getDefBoxes()) { Value v = vb.getValue(); if (localsUsed.contains(v)) { cantAggr = true; break; } if (propagatingInvokeExpr || propagatingFieldRef || propagatingArrayRef) { if (v instanceof FieldRef) { if (propagatingInvokeExpr) { cantAggr = true; break; } else if (propagatingFieldRef) { // Can't aggregate a field access if passing a definition of a field // with the same name, because they might be aliased for (FieldRef fieldRef : fieldRefList) { if (((FieldRef) v).getField() == fieldRef.getField()) { cantAggr = true; break; } } } } else if (v instanceof ArrayRef) { if (propagatingInvokeExpr) { // Cannot aggregate an invoke expr past an array write cantAggr = true; break; } else if (propagatingArrayRef) { // cannot aggregate an array read past a write // this is somewhat conservative // (if types differ they may not be aliased) cantAggr = true; break; } } } } // Make sure not propagating past a {enter,exit}Monitor if (propagatingInvokeExpr && between instanceof MonitorStmt) cantAggr = true; } // Check for intervening side effects due to method calls if (propagatingInvokeExpr || propagatingFieldRef || propagatingArrayRef) { for (final ValueBox box : between.getUseBoxes()) { if (between == use && box == useBox) { // Reached use point, stop looking for // side effects break; } Value v = box.getValue(); if (v instanceof InvokeExpr || (propagatingInvokeExpr && (v instanceof FieldRef || v instanceof ArrayRef))) { cantAggr = true; break; } } } } // we give up: can't aggregate. if (cantAggr) { continue; } /* assuming that the d-u chains are correct, */ /* we need not check the actual contents of ld */ Value aggregatee = s.getRightOp(); if (usepair.valueBox.canContainValue(aggregatee)) { boolean wasSimpleCopy = isSimpleCopy(usepair.unit); usepair.valueBox.setValue(aggregatee); units.remove(s); hadAggregation = true; // clean up the tags. If s was not a simple copy, the new statement should get // the tags of s. // OK, this fix was wrong. The condition should not be // "If s was not a simple copy", but rather "If usepair.unit // was a simple copy". This way, when there's a load of a constant // followed by an invoke, the invoke gets the tags. if (wasSimpleCopy) { // usepair.unit.removeAllTags(); usepair.unit.addAllTagsOf(s); } } else { /* if(Options.v().verbose()) { G.v().out.println("[debug] failed aggregation"); G.v().out.println("[debug] tried to put "+aggregatee+ " into "+usepair.stmt + ": in particular, "+usepair.valueBox); G.v().out.println("[debug] aggregatee instanceof Expr: " +(aggregatee instanceof Expr)); }*/ } } return hadAggregation; }