Examples with ReturnStmt soot.jimple.ReturnStmt used on opensource projects

Example 1 with ReturnStmt

use of soot.jimple.ReturnStmt in project robovm by robovm.

the class MethodCompiler method doCompile.

protected Function doCompile(ModuleBuilder moduleBuilder, SootMethod method) {
    function = createMethodFunction(method);
    moduleBuilder.addFunction(function);
    this.moduleBuilder = moduleBuilder;
    env = function.getParameterRef(0);
    trapsAt = new HashMap<Unit, List<Trap>>();
    Body body = method.retrieveActiveBody();
    NopStmt prependedNop = null;
    if (method.isStatic() && !body.getUnits().getFirst().getBoxesPointingToThis().isEmpty()) {
        // Fix for issue #1. This prevents an NPE in Soot's ArrayBoundsCheckerAnalysis. The NPE
        // occurs for static methods which start with a unit that is the target of some other
        // unit. We work around this by inserting a nop statement as the first unit in such 
        // methods. See http://www.sable.mcgill.ca/listarchives/soot-list/msg01397.html.
        Unit insertionPoint = body.getUnits().getFirst();
        prependedNop = Jimple.v().newNopStmt();
        body.getUnits().getNonPatchingChain().insertBefore(prependedNop, insertionPoint);
    }
    PackManager.v().getPack("jtp").apply(body);
    PackManager.v().getPack("jop").apply(body);
    PackManager.v().getPack("jap").apply(body);
    if (body.getUnits().getFirst() == prependedNop && prependedNop.getBoxesPointingToThis().isEmpty()) {
        // Remove the nop we inserted above to work around the bug in Soot's 
        // ArrayBoundsCheckerAnalysis which has now been run.
        body.getUnits().getNonPatchingChain().removeFirst();
    }
    PatchingChain<Unit> units = body.getUnits();
    Map<Unit, List<Unit>> branchTargets = getBranchTargets(body);
    Map<Unit, Integer> trapHandlers = getTrapHandlers(body);
    Map<Unit, Integer> selChanges = new HashMap<Unit, Integer>();
    int multiANewArrayMaxDims = 0;
    Set<Local> locals = new HashSet<Local>();
    boolean emitCheckStackOverflow = false;
    for (Unit unit : units) {
        if (unit instanceof DefinitionStmt) {
            DefinitionStmt stmt = (DefinitionStmt) unit;
            if (stmt.getLeftOp() instanceof Local) {
                Local local = (Local) stmt.getLeftOp();
                if (!locals.contains(local)) {
                    Type type = getLocalType(local.getType());
                    Alloca alloca = new Alloca(function.newVariable(local.getName(), type), type);
                    alloca.attach(local);
                    function.add(alloca);
                    locals.add(local);
                }
            }
            if (stmt.getRightOp() instanceof NewMultiArrayExpr) {
                NewMultiArrayExpr expr = (NewMultiArrayExpr) stmt.getRightOp();
                multiANewArrayMaxDims = Math.max(multiANewArrayMaxDims, expr.getSizeCount());
            }
            if (stmt.getRightOp() instanceof InvokeExpr) {
                emitCheckStackOverflow = true;
            }
        }
        if (unit instanceof InvokeStmt) {
            emitCheckStackOverflow = true;
        }
    }
    dims = null;
    if (multiANewArrayMaxDims > 0) {
        dims = function.newVariable("dims", new PointerType(new ArrayType(multiANewArrayMaxDims, I32)));
        function.add(new Alloca(dims, new ArrayType(multiANewArrayMaxDims, I32)));
    }
    if (emitCheckStackOverflow) {
        call(CHECK_STACK_OVERFLOW);
    }
    Value trycatchContext = null;
    if (!body.getTraps().isEmpty()) {
        List<List<Trap>> recordedTraps = new ArrayList<List<Trap>>();
        for (Unit unit : units) {
            // Calculate the predecessor units of unit 
            Set<Unit> incoming = new HashSet<Unit>();
            if (units.getFirst() != unit && units.getPredOf(unit).fallsThrough()) {
                incoming.add(units.getPredOf(unit));
            }
            if (branchTargets.keySet().contains(unit)) {
                incoming.addAll(branchTargets.get(unit));
            }
            if (unit == units.getFirst() || trapHandlers.containsKey(unit) || trapsDiffer(unit, incoming)) {
                List<Trap> traps = getTrapsAt(unit);
                if (traps.isEmpty()) {
                    selChanges.put(unit, 0);
                } else {
                    int index = recordedTraps.indexOf(traps);
                    if (index == -1) {
                        index = recordedTraps.size();
                        recordedTraps.add(traps);
                    }
                    selChanges.put(unit, index + 1);
                }
            }
        }
        StructureConstantBuilder landingPadsPtrs = new StructureConstantBuilder();
        for (List<Trap> traps : recordedTraps) {
            StructureConstantBuilder landingPads = new StructureConstantBuilder();
            for (Trap trap : traps) {
                SootClass exClass = trap.getException();
                StructureConstantBuilder landingPad = new StructureConstantBuilder();
                if ("java.lang.Throwable".equals(exClass.getName()) || exClass.isPhantom()) {
                    landingPad.add(new NullConstant(I8_PTR));
                } else {
                    catches.add(getInternalName(exClass));
                    if (exClass == sootClass) {
                        /*
                             * The class being compiled is an exception class
                             * with a catch clause which catches itself. We
                             * cannot reference the info struct directly since
                             * we don't know the type of it and it hasn't been
                             * emitted by ClassCompiler yet. Use the internal
                             * i8* alias instead which ClassCompiler will emit.
                             * See #1007.
                             */
                        landingPad.add(new AliasRef(Symbols.infoStructSymbol(getInternalName(exClass)) + "_i8ptr", I8_PTR));
                    } else {
                        Global g = new Global(Symbols.infoStructSymbol(getInternalName(exClass)), I8_PTR, true);
                        if (!moduleBuilder.hasSymbol(g.getName())) {
                            moduleBuilder.addGlobal(g);
                        }
                        landingPad.add(g.ref());
                    }
                }
                landingPad.add(new IntegerConstant(trapHandlers.get(trap.getHandlerUnit()) + 1));
                landingPads.add(landingPad.build());
            }
            landingPads.add(new StructureConstantBuilder().add(new NullConstant(I8_PTR)).add(new IntegerConstant(0)).build());
            Global g = moduleBuilder.newGlobal(landingPads.build(), true);
            landingPadsPtrs.add(new ConstantBitcast(g.ref(), I8_PTR));
        }
        Global g = moduleBuilder.newGlobal(landingPadsPtrs.build(), true);
        Variable ctx = function.newVariable(TRYCATCH_CONTEXT_PTR);
        Variable bcCtx = function.newVariable(BC_TRYCATCH_CONTEXT_PTR);
        function.add(new Alloca(bcCtx, BC_TRYCATCH_CONTEXT));
        Variable selPtr = function.newVariable(new PointerType(I32));
        function.add(new Getelementptr(selPtr, bcCtx.ref(), 0, 0, 1));
        function.add(new Store(new IntegerConstant(0), selPtr.ref()));
        Variable bcCtxLandingPadsPtr = function.newVariable(I8_PTR_PTR);
        function.add(new Getelementptr(bcCtxLandingPadsPtr, bcCtx.ref(), 0, 1));
        function.add(new Store(new ConstantBitcast(g.ref(), I8_PTR), bcCtxLandingPadsPtr.ref()));
        function.add(new Bitcast(ctx, bcCtx.ref(), TRYCATCH_CONTEXT_PTR));
        trycatchContext = ctx.ref();
        Value result = call(RVM_TRYCATCH_ENTER, env, trycatchContext);
        Map<IntegerConstant, BasicBlockRef> alt = new TreeMap<IntegerConstant, BasicBlockRef>();
        for (Entry<Unit, Integer> entry : trapHandlers.entrySet()) {
            alt.put(new IntegerConstant(entry.getValue() + 1), function.newBasicBlockRef(new Label(entry.getKey())));
        }
        function.add(new Switch(result, function.newBasicBlockRef(new Label(units.getFirst())), alt));
        if (!branchTargets.containsKey(units.getFirst())) {
            function.newBasicBlock(new Label(units.getFirst()));
        }
    }
    if ("<clinit>".equals(method.getName())) {
        initializeClassFields();
    }
    for (Unit unit : units) {
        if (branchTargets.containsKey(unit) || trapHandlers.containsKey(unit)) {
            BasicBlock oldBlock = function.getCurrentBasicBlock();
            function.newBasicBlock(new Label(unit));
            if (oldBlock != null) {
                Instruction last = oldBlock.last();
                if (last == null || !isTerminator(last)) {
                    oldBlock.add(new Br(function.newBasicBlockRef(new Label(unit))));
                }
            }
        }
        if (selChanges.containsKey(unit)) {
            int sel = selChanges.get(unit);
            // trycatchContext->sel = sel
            Variable selPtr = function.newVariable(new PointerType(I32));
            function.add(new Getelementptr(selPtr, trycatchContext, 0, 1)).attach(unit);
            function.add(new Store(new IntegerConstant(sel), selPtr.ref())).attach(unit);
        }
        if (unit instanceof DefinitionStmt) {
            assign((DefinitionStmt) unit);
        } else if (unit instanceof ReturnStmt) {
            if (!body.getTraps().isEmpty()) {
                trycatchLeave(function);
            }
            return_((ReturnStmt) unit);
        } else if (unit instanceof ReturnVoidStmt) {
            if (!body.getTraps().isEmpty()) {
                trycatchLeave(function);
            }
            returnVoid((ReturnVoidStmt) unit);
        } else if (unit instanceof IfStmt) {
            if_((IfStmt) unit);
        } else if (unit instanceof LookupSwitchStmt) {
            lookupSwitch((LookupSwitchStmt) unit);
        } else if (unit instanceof TableSwitchStmt) {
            tableSwitch((TableSwitchStmt) unit);
        } else if (unit instanceof GotoStmt) {
            goto_((GotoStmt) unit);
        } else if (unit instanceof ThrowStmt) {
            throw_((ThrowStmt) unit);
        } else if (unit instanceof InvokeStmt) {
            invoke((InvokeStmt) unit);
        } else if (unit instanceof EnterMonitorStmt) {
            enterMonitor((EnterMonitorStmt) unit);
        } else if (unit instanceof ExitMonitorStmt) {
            exitMonitor((ExitMonitorStmt) unit);
        } else if (unit instanceof NopStmt) {
            nop((NopStmt) unit);
        } else {
            throw new IllegalArgumentException("Unknown Unit type: " + unit.getClass());
        }
    }
    if (this.className.equals("java/lang/Object") && "<init>".equals(method.getName())) {
        // If it is the object will be registered for finalization.
        for (BasicBlock bb : function.getBasicBlocks()) {
            if (bb.last() instanceof Ret) {
                // Insert a call to register_finalizable() before this ret
                Call call = new Call(REGISTER_FINALIZABLE, env, function.getParameterRef(1));
                call.attach(bb.last().getAttachment(Unit.class));
                bb.insertBefore(bb.last(), call);
            }
        }
    }
    return function;
}