Files
sdk/lib/compiler/implementation/ssa/builder.dart
T
2012-07-11 12:34:53 +00:00

3552 lines
125 KiB
Dart

// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
class Interceptors {
Compiler compiler;
Interceptors(Compiler this.compiler);
SourceString mapOperatorToMethodName(Operator op) {
String name = op.source.stringValue;
if (name === '+') return const SourceString('add');
if (name === '-') return const SourceString('sub');
if (name === '*') return const SourceString('mul');
if (name === '/') return const SourceString('div');
if (name === '~/') return const SourceString('tdiv');
if (name === '%') return const SourceString('mod');
if (name === '<<') return const SourceString('shl');
if (name === '>>') return const SourceString('shr');
if (name === '|') return const SourceString('or');
if (name === '&') return const SourceString('and');
if (name === '^') return const SourceString('xor');
if (name === '<') return const SourceString('lt');
if (name === '<=') return const SourceString('le');
if (name === '>') return const SourceString('gt');
if (name === '>=') return const SourceString('ge');
if (name === '==') return const SourceString('eq');
if (name === '!=') return const SourceString('eq');
if (name === '===') return const SourceString('eqq');
if (name === '!==') return const SourceString('eqq');
if (name === '+=') return const SourceString('add');
if (name === '-=') return const SourceString('sub');
if (name === '*=') return const SourceString('mul');
if (name === '/=') return const SourceString('div');
if (name === '~/=') return const SourceString('tdiv');
if (name === '%=') return const SourceString('mod');
if (name === '<<=') return const SourceString('shl');
if (name === '>>=') return const SourceString('shr');
if (name === '|=') return const SourceString('or');
if (name === '&=') return const SourceString('and');
if (name === '^=') return const SourceString('xor');
if (name === '++') return const SourceString('add');
if (name === '--') return const SourceString('sub');
compiler.unimplemented('Unknown operator', node: op);
}
Element getStaticInterceptor(SourceString name, int parameters) {
String mangledName = name.slowToString();
Element element = compiler.findInterceptor(new SourceString(mangledName));
if (element !== null && element.isFunction()) {
// Only pick the function element with the short name if the
// number of parameters it expects matches the number we're
// passing modulo the receiver.
FunctionElement function = element;
if (function.parameterCount(compiler) == parameters + 1) return element;
}
String longMangledName = "$mangledName\$$parameters";
return compiler.findInterceptor(new SourceString(longMangledName));
}
Element getStaticGetInterceptor(SourceString name) {
String mangledName = "get\$${name.slowToString()}";
return compiler.findInterceptor(new SourceString(mangledName));
}
Element getStaticSetInterceptor(SourceString name) {
String mangledName = "set\$${name.slowToString()}";
return compiler.findInterceptor(new SourceString(mangledName));
}
Element getOperatorInterceptor(Operator op) {
SourceString name = mapOperatorToMethodName(op);
return compiler.findHelper(name);
}
Element getBoolifiedVersionOf(Element interceptor) {
if (interceptor === null) return interceptor;
String boolifiedName = "${interceptor.name.slowToString()}B";
return compiler.findHelper(new SourceString(boolifiedName));
}
Element getPrefixOperatorInterceptor(Operator op) {
String name = op.source.stringValue;
if (name === '~') {
return compiler.findHelper(const SourceString('not'));
}
if (name === '-') {
return compiler.findHelper(const SourceString('neg'));
}
compiler.unimplemented('Unknown operator', node: op);
}
Element getIndexInterceptor() {
return compiler.findHelper(const SourceString('index'));
}
Element getIndexAssignmentInterceptor() {
return compiler.findHelper(const SourceString('indexSet'));
}
Element getExceptionUnwrapper() {
return compiler.findHelper(const SourceString('unwrapException'));
}
Element getClosureConverter() {
return compiler.findHelper(const SourceString('convertDartClosureToJS'));
}
Element getTraceFromException() {
return compiler.findHelper(const SourceString('getTraceFromException'));
}
Element getEqualsInterceptor() {
return compiler.findHelper(const SourceString('eq'));
}
Element getTripleEqualsInterceptor() {
return compiler.findHelper(const SourceString('eqq'));
}
Element getMapMaker() {
return compiler.findHelper(const SourceString('makeLiteralMap'));
}
// TODO(karlklose): move these to different class or rename class?
Element getSetRuntimeTypeInfo() {
return compiler.findHelper(const SourceString('setRuntimeTypeInfo'));
}
Element getGetRuntimeTypeInfo() {
return compiler.findHelper(const SourceString('getRuntimeTypeInfo'));
}
}
class SsaBuilderTask extends CompilerTask {
final Interceptors interceptors;
final Map<Node, ClosureData> closureDataCache;
final CodeEmitterTask emitter;
// Loop tracking information.
final Set<FunctionElement> functionsCalledInLoop;
final Map<SourceString, Selector> selectorsCalledInLoop;
String get name() => 'SSA builder';
SsaBuilderTask(JavaScriptBackend backend)
: interceptors = new Interceptors(backend.compiler),
closureDataCache = new HashMap<Node, ClosureData>(),
emitter = backend.emitter,
functionsCalledInLoop = new Set<FunctionElement>(),
selectorsCalledInLoop = new Map<SourceString, Selector>(),
super(backend.compiler);
HGraph build(WorkItem work) {
return measure(() {
FunctionElement element = work.element;
HInstruction.idCounter = 0;
SsaBuilder builder = new SsaBuilder(this, work);
HGraph graph;
ElementKind kind = element.kind;
if (kind === ElementKind.GENERATIVE_CONSTRUCTOR) {
graph = compileConstructor(builder, work);
} else if (kind === ElementKind.GENERATIVE_CONSTRUCTOR_BODY ||
kind === ElementKind.FUNCTION ||
kind === ElementKind.GETTER ||
kind === ElementKind.SETTER) {
graph = builder.buildMethod(work.element);
}
assert(graph.isValid());
bool inLoop = functionsCalledInLoop.contains(element);
if (!inLoop) {
Selector selector = selectorsCalledInLoop[element.name];
inLoop = selector !== null && selector.applies(element, compiler);
}
graph.calledInLoop = inLoop;
if (compiler.tracer.enabled) {
String name;
if (element.enclosingElement !== null &&
element.enclosingElement.kind == ElementKind.CLASS) {
String className = element.enclosingElement.name.slowToString();
String memberName = element.name.slowToString();
name = "$className.$memberName";
if (element.kind == ElementKind.GENERATIVE_CONSTRUCTOR_BODY) {
name = "$name (body)";
}
} else {
name = "${element.name.slowToString()}";
}
compiler.tracer.traceCompilation(name);
compiler.tracer.traceGraph('builder', graph);
}
return graph;
});
}
HGraph compileConstructor(SsaBuilder builder, WorkItem work) {
// The body of the constructor will be generated in a separate function.
final ClassElement classElement = work.element.enclosingElement;
return builder.buildFactory(classElement, work.element);
}
}
/**
* Keeps track of locals (including parameters and phis) when building. The
* 'this' reference is treated as parameter and hence handled by this class,
* too.
*/
class LocalsHandler {
/**
* The values of locals that can be directly accessed (without redirections
* to boxes or closure-fields).
*/
Map<Element, HInstruction> directLocals;
Map<Element, Element> redirectionMapping;
SsaBuilder builder;
ClosureData closureData;
LocalsHandler(this.builder)
: directLocals = new Map<Element, HInstruction>(),
redirectionMapping = new Map<Element, Element>();
/**
* Creates a new [LocalsHandler] based on [other]. We only need to
* copy the [directLocals], since the other fields can be shared
* throughout the AST visit.
*/
LocalsHandler.from(LocalsHandler other)
: directLocals = new Map<Element, HInstruction>.from(other.directLocals),
redirectionMapping = other.redirectionMapping,
builder = other.builder,
closureData = other.closureData;
/**
* Redirects accesses from element [from] to element [to]. The [to] element
* must be a boxed variable or a variable that is stored in a closure-field.
*/
void redirectElement(Element from, Element to) {
assert(redirectionMapping[from] === null);
redirectionMapping[from] = to;
assert(isStoredInClosureField(from) || isBoxed(from));
}
HInstruction createBox() {
// TODO(floitsch): Clean up this hack. Should we create a box-object by
// just creating an empty object literal?
HInstruction box = new HForeign(const LiteralDartString("{}"),
const LiteralDartString('Object'),
<HInstruction>[]);
builder.add(box);
return box;
}
/**
* If the scope (function or loop) [node] has captured variables then this
* method creates a box and sets up the redirections.
*/
void enterScope(Node node) {
// See if any variable in the top-scope of the function is captured. If yes
// we need to create a box-object.
ClosureScope scopeData = closureData.capturingScopes[node];
if (scopeData !== null) {
// The scope has captured variables. Create a box.
// TODO(floitsch): Clean up this hack. Should we create a box-object by
// just creating an empty object literal?
HInstruction box = createBox();
// Add the box to the known locals.
directLocals[scopeData.boxElement] = box;
// Make sure that accesses to the boxed locals go into the box. We also
// need to make sure that parameters are copied into the box if necessary.
scopeData.capturedVariableMapping.forEach((Element from, Element to) {
// The [from] can only be a parameter for function-scopes and not
// loop scopes.
if (from.kind == ElementKind.PARAMETER) {
// Store the captured parameter in the box. Get the current value
// before we put the redirection in place.
HInstruction instruction = readLocal(from);
redirectElement(from, to);
// Now that the redirection is set up, the update to the local will
// write the parameter value into the box.
updateLocal(from, instruction);
} else {
redirectElement(from, to);
}
});
}
}
/**
* Replaces the current box with a new box and copies over the given list
* of elements from the old box into the new box.
*/
void updateCaptureBox(Element boxElement, List<Element> toBeCopiedElements) {
// Create a new box and copy over the values from the old box into the
// new one.
HInstruction oldBox = readLocal(boxElement);
HInstruction newBox = createBox();
for (Element boxedVariable in toBeCopiedElements) {
// [readLocal] uses the [boxElement] to find its box. By replacing it
// behind its back we can still get to the old values.
updateLocal(boxElement, oldBox);
HInstruction oldValue = readLocal(boxedVariable);
updateLocal(boxElement, newBox);
updateLocal(boxedVariable, oldValue);
}
updateLocal(boxElement, newBox);
}
void startFunction(FunctionElement function,
FunctionExpression node) {
ClosureTranslator translator = new ClosureTranslator(builder);
closureData = translator.translate(node);
FunctionSignature signature = function.computeSignature(builder.compiler);
signature.forEachParameter((Element element) {
HInstruction parameter = new HParameterValue(element);
builder.add(parameter);
builder.parameters[element] = parameter;
directLocals[element] = parameter;
});
enterScope(node);
// If the freeVariableMapping is not empty, then this function was a
// nested closure that captures variables. Redirect the captured
// variables to fields in the closure.
closureData.freeVariableMapping.forEach((Element from, Element to) {
redirectElement(from, to);
});
if (closureData.isClosure()) {
// Inside closure redirect references to itself to [:this:].
HInstruction thisInstruction = new HThis();
builder.add(thisInstruction);
updateLocal(closureData.closureElement, thisInstruction);
} else if (function.isInstanceMember()
|| function.isGenerativeConstructor()) {
// Once closures have been mapped to classes their instance members might
// not have any thisElement if the closure was created inside a static
// context.
ClassElement cls = function.enclosingElement;
Type type = cls.computeType(builder.compiler);
HInstruction thisInstruction = new HThis(new HBoundedType.nonNull(type));
builder.add(thisInstruction);
directLocals[closureData.thisElement] = thisInstruction;
}
}
bool hasValueForDirectLocal(Element element) {
assert(element !== null);
assert(isAccessedDirectly(element));
return directLocals[element] !== null;
}
/**
* Returns true if the local can be accessed directly. Boxed variables or
* captured variables that are stored in the closure-field return [false].
*/
bool isAccessedDirectly(Element element) {
assert(element !== null);
return redirectionMapping[element] === null
&& !closureData.usedVariablesInTry.contains(element);
}
bool isStoredInClosureField(Element element) {
assert(element !== null);
if (isAccessedDirectly(element)) return false;
Element redirectTarget = redirectionMapping[element];
if (redirectTarget == null) return false;
if (redirectTarget.enclosingElement.kind == ElementKind.CLASS) {
assert(redirectTarget is ClosureFieldElement);
return true;
}
return false;
}
bool isBoxed(Element element) {
if (isAccessedDirectly(element)) return false;
if (isStoredInClosureField(element)) return false;
return redirectionMapping[element] !== null;
}
bool isUsedInTry(Element element) {
return closureData.usedVariablesInTry.contains(element);
}
/**
* Returns an [HInstruction] for the given element. If the element is
* boxed or stored in a closure then the method generates code to retrieve
* the value.
*/
HInstruction readLocal(Element element) {
if (isAccessedDirectly(element)) {
if (directLocals[element] == null) {
builder.compiler.internalError("Cannot find value $element",
element: element);
}
return directLocals[element];
} else if (isStoredInClosureField(element)) {
Element redirect = redirectionMapping[element];
HInstruction receiver = readLocal(closureData.closureElement);
HInstruction fieldGet = new HFieldGet(redirect, receiver);
builder.add(fieldGet);
return fieldGet;
} else if (isBoxed(element)) {
Element redirect = redirectionMapping[element];
// In the function that declares the captured variable the box is
// accessed as direct local. Inside the nested closure the box is
// accessed through a closure-field.
// Calling [readLocal] makes sure we generate the correct code to get
// the box.
assert(redirect.enclosingElement.kind == ElementKind.VARIABLE);
HInstruction box = readLocal(redirect.enclosingElement);
HInstruction lookup = new HFieldGet(redirect, box);
builder.add(lookup);
return lookup;
} else {
assert(isUsedInTry(element));
HLocalValue local = getLocal(element);
HInstruction variable = new HLocalGet(element, local);
builder.add(variable);
return variable;
}
}
HType cachedTypeOfThis;
HInstruction readThis() {
HInstruction res = readLocal(closureData.thisElement);
if (res.guaranteedType === null) {
if (cachedTypeOfThis === null) {
assert(closureData.isClosure());
Element element = closureData.thisElement;
ClassElement cls = element.enclosingElement.enclosingElement;
Type type = cls.computeType(builder.compiler);
cachedTypeOfThis = new HBoundedType.nonNull(type);
}
res.guaranteedType = cachedTypeOfThis;
}
return res;
}
HLocalValue getLocal(Element element) {
// If the element is a parameter, we already have a
// HParameterValue for it. We cannot create another one because
// it could then have another name than the real parameter. And
// the other one would not know it is just a copy of the real
// parameter.
if (element.isParameter()) return builder.parameters[element];
return builder.activationVariables.putIfAbsent(element, () {
HLocalValue local = new HLocalValue(element);
builder.graph.entry.addAtExit(local);
return local;
});
}
/**
* Sets the [element] to [value]. If the element is boxed or stored in a
* closure then the method generates code to set the value.
*/
void updateLocal(Element element, HInstruction value) {
assert(!isStoredInClosureField(element));
if (isAccessedDirectly(element)) {
directLocals[element] = value;
} else if (isBoxed(element)) {
Element redirect = redirectionMapping[element];
// The box itself could be captured, or be local. A local variable that
// is captured will be boxed, but the box itself will be a local.
// Inside the closure the box is stored in a closure-field and cannot
// be accessed directly.
assert(redirect.enclosingElement.kind == ElementKind.VARIABLE);
HInstruction box = readLocal(redirect.enclosingElement);
builder.add(new HFieldSet(redirect, box, value));
} else {
assert(isUsedInTry(element));
HLocalValue local = getLocal(element);
builder.add(new HLocalSet(element, local, value));
}
}
/**
* This function must be called before visiting any children of the loop. In
* particular it needs to be called before executing the initializers.
*
* The [LocalsHandler] will make the boxes and updates at the right moment.
* The builder just needs to call [enterLoopBody] and [enterLoopUpdates] (for
* [For] loops) at the correct places. For phi-handling [beginLoopHeader] and
* [endLoop] must also be called.
*
* The correct place for the box depends on the given loop. In most cases
* the box will be created when entering the loop-body: while, do-while, and
* for-in (assuming the call to [:next:] is inside the body) can always be
* constructed this way.
*
* Things are slightly more complicated for [For] loops. If no declared
* loop variable is boxed then the loop-body approach works here too. If a
* loop-variable is boxed we need to introduce a new box for the
* loop-variable before we enter the initializer so that the initializer
* writes the values into the box. In any case we need to create the box
* before the condition since the condition could box the variable.
* Since the first box is created outside the actual loop we have a second
* location where a box is created: just before the updates. This is
* necessary since updates are considered to be part of the next iteration
* (and can again capture variables).
*
* For example the following Dart code prints 1 3 -- 3 4.
*
* var fs = [];
* for (var i = 0; i < 3; (f() { fs.add(f); print(i); i++; })()) {
* i++;
* }
* print("--");
* for (var i = 0; i < 2; i++) fs[i]();
*
* We solve this by emitting the following code (only for [For] loops):
* <Create box> <== move the first box creation outside the loop.
* <initializer>;
* loop-entry:
* if (!<condition>) goto loop-exit;
* <body>
* <update box> // create a new box and copy the captured loop-variables.
* <updates>
* goto loop-entry;
* loop-exit:
*/
void startLoop(Node node) {
ClosureScope scopeData = closureData.capturingScopes[node];
if (scopeData == null) return;
if (scopeData.hasBoxedLoopVariables()) {
// If there are boxed loop variables then we set up the box and
// redirections already now. This way the initializer can write its
// values into the box.
// For other loops the box will be created when entering the body.
enterScope(node);
}
}
void beginLoopHeader(Node node, HBasicBlock loopEntry) {
// Create a copy because we modify the map while iterating over
// it.
Map<Element, HInstruction> saved =
new Map<Element, HInstruction>.from(directLocals);
// Create phis for all elements in the definitions environment.
saved.forEach((Element element, HInstruction instruction) {
if (isAccessedDirectly(element)) {
// We know 'this' cannot be modified.
if (element !== closureData.thisElement) {
HPhi phi = new HPhi.singleInput(element, instruction);
loopEntry.addPhi(phi);
directLocals[element] = phi;
} else {
directLocals[element] = instruction;
}
}
});
}
void enterLoopBody(Node node) {
ClosureScope scopeData = closureData.capturingScopes[node];
if (scopeData == null) return;
// If there are no declared boxed loop variables then we did not create the
// box before the initializer and we have to create the box now.
if (!scopeData.hasBoxedLoopVariables()) {
enterScope(node);
}
}
void enterLoopUpdates(Loop node) {
// If there are declared boxed loop variables then the updates might have
// access to the box and we must switch to a new box before executing the
// updates.
// In all other cases a new box will be created when entering the body of
// the next iteration.
ClosureScope scopeData = closureData.capturingScopes[node];
if (scopeData == null) return;
if (scopeData.hasBoxedLoopVariables()) {
updateCaptureBox(scopeData.boxElement, scopeData.boxedLoopVariables);
}
}
void endLoop(HBasicBlock loopEntry) {
loopEntry.forEachPhi((HPhi phi) {
Element element = phi.sourceElement;
HInstruction postLoopDefinition = directLocals[element];
phi.addInput(postLoopDefinition);
});
}
/**
* Merge [otherLocals] into this locals handler, creating phi-nodes when
* there is a conflict.
* If a phi node is necessary, it will use this handler's instruction as the
* first input, and the otherLocals instruction as the second.
*/
void mergeWith(LocalsHandler otherLocals, HBasicBlock joinBlock) {
// If an element is in one map but not the other we can safely
// ignore it. It means that a variable was declared in the
// block. Since variable declarations are scoped the declared
// variable cannot be alive outside the block. Note: this is only
// true for nodes where we do joins.
Map<Element, HInstruction> joinedLocals = new Map<Element, HInstruction>();
otherLocals.directLocals.forEach((element, instruction) {
// We know 'this' cannot be modified.
if (element === closureData.thisElement) {
assert(directLocals[element] == instruction);
joinedLocals[element] = instruction;
} else {
HInstruction mine = directLocals[element];
if (mine === null) return;
if (instruction === mine) {
joinedLocals[element] = instruction;
} else {
HInstruction phi =
new HPhi.manyInputs(element, <HInstruction>[mine, instruction]);
joinBlock.addPhi(phi);
joinedLocals[element] = phi;
}
}
});
directLocals = joinedLocals;
}
/**
* The current localsHandler is not used for its values, only for its
* declared variables. This is a way to exclude local values from the
* result when they are no longer in scope.
* Returns the new LocalsHandler to use (may not be [this]).
*/
LocalsHandler mergeMultiple(List<LocalsHandler> locals,
HBasicBlock joinBlock) {
assert(locals.length > 0);
if (locals.length == 1) return locals[0];
Map<Element, HInstruction> joinedLocals = new Map<Element,HInstruction>();
HInstruction thisValue = null;
directLocals.forEach((Element element, HInstruction instruction) {
if (element !== closureData.thisElement) {
HPhi phi = new HPhi.noInputs(element);
joinedLocals[element] = phi;
joinBlock.addPhi(phi);
} else {
// We know that "this" never changes, if it's there.
// Save it for later. While merging, there is no phi for "this",
// so we don't have to special case it in the merge loop.
thisValue = instruction;
}
});
for (LocalsHandler local in locals) {
local.directLocals.forEach((Element element, HInstruction instruction) {
HPhi phi = joinedLocals[element];
if (phi !== null) {
phi.addInput(instruction);
}
});
}
if (thisValue !== null) {
// If there was a "this" for the scope, add it to the new locals.
joinedLocals[closureData.thisElement] = thisValue;
}
directLocals = joinedLocals;
return this;
}
}
// Represents a single break/continue instruction.
class JumpHandlerEntry {
final HJump jumpInstruction;
final LocalsHandler locals;
bool isBreak() => jumpInstruction is HBreak;
bool isContinue() => jumpInstruction is HContinue;
JumpHandlerEntry(this.jumpInstruction, this.locals);
}
interface JumpHandler default JumpHandlerImpl {
JumpHandler(SsaBuilder builder, TargetElement target);
void generateBreak([LabelElement label]);
void generateContinue([LabelElement label]);
void forEachBreak(void action(HBreak instruction, LocalsHandler locals));
void forEachContinue(void action(HContinue instruction,
LocalsHandler locals));
void close();
final TargetElement target;
List<LabelElement> labels();
}
// Insert break handler used to avoid null checks when a target isn't
// used as the target of a break, and therefore doesn't need a break
// handler associated with it.
class NullJumpHandler implements JumpHandler {
final Compiler compiler;
NullJumpHandler(this.compiler);
void generateBreak([LabelElement label]) {
// TODO(lrn): Need a compiler object and a location. Since label
// is optional, it may be null so we also need a position.
compiler.internalError('generateBreak should not be called');
}
void generateContinue([LabelElement label]) {
// TODO(lrn): Need a compiler object and a location. Since label
// is optional, it may be null so we also need a position.
compiler.internalError('generateContinue should not be called');
}
void forEachBreak(Function ignored) { }
void forEachContinue(Function ignored) { }
void close() { }
final TargetElement target = null;
List<LabelElement> labels() => const <LabelElement>[];
}
// Records breaks until a target block is available.
// Breaks are always forward jumps.
// Continues in loops are implemented as breaks of the body.
// Continues in switches is currently not handled.
class JumpHandlerImpl implements JumpHandler {
final SsaBuilder builder;
final TargetElement target;
final List<JumpHandlerEntry> jumps;
JumpHandlerImpl(SsaBuilder builder, this.target)
: this.builder = builder,
jumps = <JumpHandlerEntry>[] {
assert(builder.jumpTargets[target] === null);
builder.jumpTargets[target] = this;
}
void generateBreak([LabelElement label]) {
HInstruction breakInstruction;
if (label === null) {
breakInstruction = new HBreak(target);
} else {
breakInstruction = new HBreak.toLabel(label);
}
LocalsHandler locals = new LocalsHandler.from(builder.localsHandler);
builder.close(breakInstruction);
jumps.add(new JumpHandlerEntry(breakInstruction, locals));
}
void generateContinue([LabelElement label]) {
HInstruction continueInstruction;
if (label === null) {
continueInstruction = new HContinue(target);
} else {
continueInstruction = new HContinue.toLabel(label);
}
LocalsHandler locals = new LocalsHandler.from(builder.localsHandler);
builder.close(continueInstruction);
jumps.add(new JumpHandlerEntry(continueInstruction, locals));
}
void forEachBreak(Function action) {
for (JumpHandlerEntry entry in jumps) {
if (entry.isBreak()) action(entry.jumpInstruction, entry.locals);
}
}
void forEachContinue(Function action) {
for (JumpHandlerEntry entry in jumps) {
if (entry.isContinue()) action(entry.jumpInstruction, entry.locals);
}
}
void close() {
// The mapping from TargetElement to JumpHandler is no longer needed.
builder.jumpTargets.remove(target);
}
List<LabelElement> labels() {
List<LabelElement> result = null;
for (LabelElement element in target.labels) {
if (result === null) result = <LabelElement>[];
result.add(element);
}
return (result === null) ? const <LabelElement>[] : result;
}
}
class SsaBuilder extends ResolvedVisitor implements Visitor {
final SsaBuilderTask builder;
final Interceptors interceptors;
final WorkItem work;
bool methodInterceptionEnabled;
HGraph graph;
LocalsHandler localsHandler;
HInstruction rethrowableException;
Map<Element, HParameterValue> parameters;
Map<TargetElement, JumpHandler> jumpTargets;
/**
* Variables stored in the current activation. These variables are
* being updated in try/catch blocks, and should be
* accessed indirectly through HFieldGet and HFieldSet.
*/
Map<Element, HLocalValue> activationVariables;
// We build the Ssa graph by simulating a stack machine.
List<HInstruction> stack;
// The current block to add instructions to. Might be null, if we are
// visiting dead code.
HBasicBlock current;
// The most recently opened block. Has the same value as [current] while
// the block is open, but unlike [current], it isn't cleared when the current
// block is closed.
HBasicBlock lastOpenedBlock;
LibraryElement get currentLibrary() => work.element.getLibrary();
Compiler get compiler() => builder.compiler;
CodeEmitterTask get emitter() => builder.emitter;
SsaBuilder(SsaBuilderTask builder, WorkItem work)
: this.builder = builder,
this.work = work,
interceptors = builder.interceptors,
methodInterceptionEnabled = true,
graph = new HGraph(),
stack = new List<HInstruction>(),
activationVariables = new Map<Element, HLocalValue>(),
jumpTargets = new Map<TargetElement, JumpHandler>(),
parameters = new Map<Element, HParameterValue>(),
super(work.resolutionTree) {
localsHandler = new LocalsHandler(this);
}
void disableMethodInterception() {
assert(methodInterceptionEnabled);
methodInterceptionEnabled = false;
}
void enableMethodInterception() {
assert(!methodInterceptionEnabled);
methodInterceptionEnabled = true;
}
HGraph buildMethod(FunctionElement functionElement) {
FunctionExpression function = functionElement.parseNode(compiler);
openFunction(functionElement, function);
function.body.accept(this);
return closeFunction();
}
/**
* Returns the constructor body associated with the given constructor or
* creates a new constructor body, if none can be found.
*
* Returns [:null:] if the constructor does not have a body.
*/
ConstructorBodyElement getConstructorBody(FunctionElement constructor) {
assert(constructor.kind === ElementKind.GENERATIVE_CONSTRUCTOR);
if (constructor is SynthesizedConstructorElement) return null;
FunctionExpression node = constructor.parseNode(compiler);
// If we know the body doesn't have any code, we don't generate
// it.
if (node.body.asBlock() !== null) {
NodeList statements = node.body.asBlock().statements;
if (statements.isEmpty()) return null;
}
ClassElement classElement = constructor.enclosingElement;
ConstructorBodyElement bodyElement;
for (Link<Element> backendMembers = classElement.backendMembers;
!backendMembers.isEmpty();
backendMembers = backendMembers.tail) {
Element backendMember = backendMembers.head;
if (backendMember.kind == ElementKind.GENERATIVE_CONSTRUCTOR_BODY) {
ConstructorBodyElement body = backendMember;
if (body.constructor == constructor) {
bodyElement = backendMember;
break;
}
}
}
if (bodyElement === null) {
bodyElement = new ConstructorBodyElement(constructor);
TreeElements treeElements =
compiler.resolver.resolveMethodElement(constructor);
compiler.enqueuer.codegen.addToWorkList(bodyElement, treeElements);
classElement.backendMembers =
classElement.backendMembers.prepend(bodyElement);
}
assert(bodyElement.kind === ElementKind.GENERATIVE_CONSTRUCTOR_BODY);
return bodyElement;
}
void inlineSuperOrRedirect(FunctionElement constructor,
Selector selector,
Link<Node> arguments,
List<FunctionElement> constructors,
Map<Element, HInstruction> fieldValues) {
constructors.addLast(constructor);
List<HInstruction> compiledArguments = new List<HInstruction>();
bool succeeded = addStaticSendArgumentsToList(selector,
arguments,
constructor,
compiledArguments);
if (!succeeded) {
// Non-matching super and redirects are compile-time errors and thus
// checked by the resolver.
compiler.internalError(
"Parameters and arguments didn't match for super/redirect call",
element: constructor);
}
int index = 0;
FunctionSignature params = constructor.computeSignature(compiler);
params.forEachParameter((Element parameter) {
HInstruction argument = compiledArguments[index++];
localsHandler.updateLocal(parameter, argument);
// Don't forget to update the field, if the parameter is of the
// form [:this.x:].
if (parameter.kind == ElementKind.FIELD_PARAMETER) {
FieldParameterElement fieldParameterElement = parameter;
fieldValues[fieldParameterElement.fieldElement] = argument;
}
});
// Build the initializers in the context of the new constructor.
TreeElements oldElements = elements;
elements = compiler.resolver.resolveMethodElement(constructor);
buildInitializers(constructor, constructors, fieldValues);
elements = oldElements;
}
/**
* Run through the initializers and inline all field initializers. Recursively
* inlines super initializers.
*
* The constructors of the inlined initializers is added to [constructors]
* with sub constructors having a lower index than super constructors.
*/
void buildInitializers(FunctionElement constructor,
List<FunctionElement> constructors,
Map<Element, HInstruction> fieldValues) {
FunctionExpression functionNode = constructor.parseNode(compiler);
bool foundSuperOrRedirect = false;
if (functionNode.initializers !== null) {
Link<Node> initializers = functionNode.initializers.nodes;
for (Link<Node> link = initializers; !link.isEmpty(); link = link.tail) {
assert(link.head is Send);
if (link.head is !SendSet) {
// A super initializer or constructor redirection.
Send call = link.head;
assert(Initializers.isSuperConstructorCall(call) ||
Initializers.isConstructorRedirect(call));
FunctionElement target = elements[call];
Selector selector = elements.getSelector(call);
Link<Node> arguments = call.arguments;
inlineSuperOrRedirect(target, selector, arguments, constructors,
fieldValues);
foundSuperOrRedirect = true;
} else {
// A field initializer.
SendSet init = link.head;
Link<Node> arguments = init.arguments;
assert(!arguments.isEmpty() && arguments.tail.isEmpty());
visit(arguments.head);
fieldValues[elements[init]] = pop();
}
}
}
if (!foundSuperOrRedirect) {
// No super initializer found. Try to find the default constructor if
// the class is not Object.
ClassElement enclosingClass = constructor.enclosingElement;
ClassElement superClass = enclosingClass.superclass;
if (enclosingClass != compiler.objectClass) {
assert(superClass !== null);
assert(superClass.isResolved);
FunctionElement target = superClass.lookupConstructor(superClass.name);
if (target === null) {
compiler.internalError("no default constructor available");
}
inlineSuperOrRedirect(target,
Selector.INVOCATION_0,
const EmptyLink<Node>(),
constructors,
fieldValues);
}
}
}
/**
* Build the factory function corresponding to the constructor
* [functionElement]:
* - Initialize fields with the values of the field initializers of the
* current constructor and super constructors or constructors redirected
* to, starting from the current constructor.
* - Call the the constructor bodies, starting from the constructor(s) in the
* super class(es).
*/
HGraph buildFactory(ClassElement classElement,
FunctionElement functionElement) {
FunctionExpression function = functionElement.parseNode(compiler);
// Note that constructors (like any other static function) do not need
// to deal with optional arguments. It is the callers job to provide all
// arguments as if they were positional.
// The initializer list could contain closures.
openFunction(functionElement, function);
Map<Element, HInstruction> fieldValues = new Map<Element, HInstruction>();
FunctionSignature params = functionElement.computeSignature(compiler);
params.forEachParameter((Element element) {
if (element.kind == ElementKind.FIELD_PARAMETER) {
// If the [element] is a field-parameter (such as [:this.x:] then
// initialize the field element with its value.
FieldParameterElement fieldParameterElement = element;
HInstruction parameterValue = localsHandler.readLocal(element);
fieldValues[fieldParameterElement.fieldElement] = parameterValue;
}
});
final Map<FunctionElement, TreeElements> constructorElements =
compiler.resolver.constructorElements;
List<FunctionElement> constructors = <FunctionElement>[functionElement];
// Analyze the constructor and all referenced constructors and collect
// initializers and constructor bodies.
buildInitializers(functionElement, constructors, fieldValues);
// Call the JavaScript constructor with the fields as argument.
List<HInstruction> constructorArguments = <HInstruction>[];
classElement.forEachInstanceField(
includeBackendMembers: true,
includeSuperMembers: true,
f: (ClassElement enclosingClass, Element member) {
HInstruction value = fieldValues[member];
if (value === null) {
// The field has no value in the initializer list. Initialize it
// with the declaration-site constant (if any).
Constant fieldValue = compiler.constantHandler.compileVariable(member);
value = graph.addConstant(fieldValue);
}
constructorArguments.add(value);
});
HForeignNew newObject = new HForeignNew(classElement, constructorArguments);
add(newObject);
// Generate calls to the constructor bodies.
for (int index = constructors.length - 1; index >= 0; index--) {
FunctionElement constructor = constructors[index];
ConstructorBodyElement body = getConstructorBody(constructor);
if (body === null) continue;
List bodyCallInputs = <HInstruction>[];
bodyCallInputs.add(newObject);
body.functionSignature.forEachParameter((parameter) {
bodyCallInputs.add(localsHandler.readLocal(parameter));
});
// TODO(ahe): The constructor name is statically resolved. See
// SsaCodeGenerator.visitInvokeDynamicMethod. Is there a cleaner
// way to do this?
SourceString methodName = new SourceString(compiler.namer.getName(body));
add(new HInvokeDynamicMethod(null, methodName, bodyCallInputs));
}
close(new HReturn(newObject)).addSuccessor(graph.exit);
return closeFunction();
}
void openFunction(FunctionElement functionElement,
FunctionExpression node) {
HBasicBlock block = graph.addNewBlock();
open(graph.entry);
localsHandler.startFunction(functionElement, node);
close(new HGoto()).addSuccessor(block);
open(block);
// Put the type checks in the first successor of the entry,
// because that is where the type guards will also be inserted.
// This way we ensure that a type guard will dominate the type
// check.
FunctionSignature params = functionElement.computeSignature(compiler);
params.forEachParameter((Element element) {
HInstruction newParameter = potentiallyCheckType(
localsHandler.directLocals[element], element);
localsHandler.directLocals[element] = newParameter;
});
}
HInstruction potentiallyCheckType(HInstruction original,
Element sourceElement) {
if (!compiler.enableTypeAssertions) return original;
return convertType(original, sourceElement,
HTypeConversion.CHECKED_MODE_CHECK);
}
HInstruction convertType(HInstruction original,
Element sourceElement,
int kind) {
Type type = sourceElement.computeType(compiler);
if (type === null) return original;
if (type.element === compiler.dynamicClass) return original;
if (type.element === compiler.objectClass) return original;
// If the original can't be null, type conversion also can't produce null.
bool canBeNull = original.guaranteedType.canBeNull();
HType convertedType =
new HType.fromBoundedType(type, compiler, canBeNull);
// No need to convert if we know the instruction has
// [convertedType] as a bound.
if (original.guaranteedType == convertedType) {
return original;
}
HInstruction instruction =
new HTypeConversion(convertedType, original, kind);
add(instruction);
return instruction;
}
HGraph closeFunction() {
// TODO(kasperl): Make this goto an implicit return.
if (!isAborted()) close(new HGoto()).addSuccessor(graph.exit);
graph.finalize();
return graph;
}
HBasicBlock addNewBlock() {
HBasicBlock block = graph.addNewBlock();
// If adding a new block during building of an expression, it is due to
// conditional expressions or short-circuit logical operators.
return block;
}
void open(HBasicBlock block) {
block.open();
current = block;
lastOpenedBlock = block;
}
HBasicBlock close(HControlFlow end) {
HBasicBlock result = current;
current.close(end);
current = null;
return result;
}
void goto(HBasicBlock from, HBasicBlock to) {
from.close(new HGoto());
from.addSuccessor(to);
}
bool isAborted() {
return current === null;
}
/**
* Creates a new block, transitions to it from any current block, and
* opens the new block.
*/
HBasicBlock openNewBlock() {
HBasicBlock newBlock = addNewBlock();
if (!isAborted()) goto(current, newBlock);
open(newBlock);
return newBlock;
}
void add(HInstruction instruction) {
current.add(instruction);
}
void push(HInstruction instruction) {
add(instruction);
stack.add(instruction);
}
HInstruction pop() {
return stack.removeLast();
}
void dup() {
stack.add(stack.last());
}
HBoolify popBoolified() {
HBoolify boolified = new HBoolify(pop());
add(boolified);
return boolified;
}
void visit(Node node) {
if (node !== null) node.accept(this);
}
visitBlock(Block node) {
for (Link<Node> link = node.statements.nodes;
!link.isEmpty();
link = link.tail) {
visit(link.head);
if (isAborted()) {
// The block has been aborted by a return or a throw.
if (!stack.isEmpty()) compiler.cancel('non-empty instruction stack');
return;
}
}
assert(!current.isClosed());
if (!stack.isEmpty()) compiler.cancel('non-empty instruction stack');
}
visitClassNode(ClassNode node) {
compiler.internalError('visitClassNode should not be called', node: node);
}
visitExpressionStatement(ExpressionStatement node) {
visit(node.expression);
pop();
}
/**
* Creates a new loop-header block. The previous [current] block
* is closed with an [HGoto] and replaced by the newly created block.
* Also notifies the locals handler that we're entering a loop.
*/
JumpHandler beginLoopHeader(Node node) {
assert(!isAborted());
HBasicBlock previousBlock = close(new HGoto());
JumpHandler jumpHandler = createJumpHandler(node);
HBasicBlock loopEntry = graph.addNewLoopHeaderBlock(
jumpHandler.target,
jumpHandler.labels());
previousBlock.addSuccessor(loopEntry);
open(loopEntry);
localsHandler.beginLoopHeader(node, loopEntry);
return jumpHandler;
}
/**
* Ends the loop:
* - creates a new block and adds it as successor to the [branchBlock].
* - opens the new block (setting as [current]).
* - notifies the locals handler that we're exiting a loop.
*/
void endLoop(HBasicBlock loopEntry,
HBasicBlock branchBlock,
JumpHandler jumpHandler,
LocalsHandler savedLocals) {
HBasicBlock loopExitBlock = addNewBlock();
assert(branchBlock.successors.length == 1);
List<LocalsHandler> breakLocals = <LocalsHandler>[];
jumpHandler.forEachBreak((HBreak breakInstruction, LocalsHandler locals) {
breakInstruction.block.addSuccessor(loopExitBlock);
breakLocals.add(locals);
});
branchBlock.addSuccessor(loopExitBlock);
open(loopExitBlock);
localsHandler.endLoop(loopEntry);
if (!breakLocals.isEmpty()) {
breakLocals.add(savedLocals);
localsHandler = savedLocals.mergeMultiple(breakLocals, loopExitBlock);
} else {
localsHandler = savedLocals;
}
}
HSubGraphBlockInformation wrapStatementGraph(SubGraph statements) {
if (statements === null) return null;
return new HSubGraphBlockInformation(statements);
}
HSubExpressionBlockInformation wrapExpressionGraph(SubExpression expression) {
if (expression === null) return null;
return new HSubExpressionBlockInformation(expression);
}
// For while loops, initializer and update are null.
// The condition function must return a boolean result.
// None of the functions must leave anything on the stack.
handleLoop(Node loop,
void initialize(),
HInstruction condition(),
void update(),
void body()) {
// Generate:
// <initializer>
// loop-entry:
// if (!<condition>) goto loop-exit;
// <body>
// <updates>
// goto loop-entry;
// loop-exit:
localsHandler.startLoop(loop);
// The initializer.
SubExpression initializerGraph = null;
HBasicBlock startBlock;
if (initialize !== null) {
HBasicBlock initializerBlock = openNewBlock();
startBlock = initializerBlock;
initialize();
assert(!isAborted());
initializerGraph =
new SubExpression(initializerBlock, current);
}
JumpHandler jumpHandler = beginLoopHeader(loop);
HLoopInformation loopInfo = current.loopInformation;
HBasicBlock conditionBlock = current;
if (startBlock === null) startBlock = conditionBlock;
HInstruction conditionInstruction = condition();
HBasicBlock conditionExitBlock =
close(new HLoopBranch(conditionInstruction));
SubExpression conditionExpression =
new SubExpression(conditionBlock, conditionExitBlock);
LocalsHandler savedLocals = new LocalsHandler.from(localsHandler);
// The body.
HBasicBlock beginBodyBlock = addNewBlock();
conditionExitBlock.addSuccessor(beginBodyBlock);
open(beginBodyBlock);
localsHandler.enterLoopBody(loop);
hackAroundPossiblyAbortingBody(loop, body);
SubGraph bodyGraph = new SubGraph(beginBodyBlock, current);
HBasicBlock bodyBlock = close(new HGoto());
// Update.
// We create an update block, even when we are in a while loop. There the
// update block is the jump-target for continue statements. We could avoid
// the creation if there is no continue, but for now we always create it.
HBasicBlock updateBlock = addNewBlock();
List<LocalsHandler> continueLocals = <LocalsHandler>[];
jumpHandler.forEachContinue((HContinue instruction, LocalsHandler locals) {
instruction.block.addSuccessor(updateBlock);
continueLocals.add(locals);
});
bodyBlock.addSuccessor(updateBlock);
continueLocals.add(localsHandler);
open(updateBlock);
localsHandler = localsHandler.mergeMultiple(continueLocals, updateBlock);
HLabeledBlockInformation labelInfo;
List<LabelElement> labels = jumpHandler.labels();
TargetElement target = elements[loop];
if (!labels.isEmpty()) {
beginBodyBlock.setBlockFlow(
new HLabeledBlockInformation(
new HSubGraphBlockInformation(bodyGraph),
jumpHandler.labels(),
isContinue: true),
updateBlock);
} else if (target !== null && target.isContinueTarget) {
beginBodyBlock.setBlockFlow(
new HLabeledBlockInformation.implicit(
new HSubGraphBlockInformation(bodyGraph),
target,
isContinue: true),
updateBlock);
}
localsHandler.enterLoopUpdates(loop);
update();
HBasicBlock updateEndBlock = close(new HGoto());
// The back-edge completing the cycle.
updateEndBlock.addSuccessor(conditionBlock);
conditionBlock.postProcessLoopHeader();
SubExpression updateGraph = new SubExpression(updateBlock, updateEndBlock);
endLoop(conditionBlock, conditionExitBlock, jumpHandler, savedLocals);
HLoopBlockInformation info =
new HLoopBlockInformation(
HLoopBlockInformation.loopType(loop),
wrapExpressionGraph(initializerGraph),
wrapExpressionGraph(conditionExpression),
wrapStatementGraph(bodyGraph),
wrapExpressionGraph(updateGraph),
conditionBlock.loopInformation.target,
conditionBlock.loopInformation.labels);
startBlock.setBlockFlow(info, current);
loopInfo.loopBlockInformation = info;
}
visitFor(For node) {
assert(node.body !== null);
void buildInitializer() {
if (node.initializer === null) return;
Node initializer = node.initializer;
if (initializer !== null) {
visit(initializer);
if (initializer.asExpression() !== null) {
pop();
}
}
}
HInstruction buildCondition() {
if (node.condition === null) {
return graph.addConstantBool(true);
}
visit(node.condition);
return popBoolified();
}
void buildUpdate() {
for (Expression expression in node.update) {
visit(expression);
assert(!isAborted());
// The result of the update instruction isn't used, and can just
// be dropped.
HInstruction updateInstruction = pop();
}
}
void buildBody() {
visit(node.body);
}
handleLoop(node, buildInitializer, buildCondition, buildUpdate, buildBody);
}
visitWhile(While node) {
HInstruction buildCondition() {
visit(node.condition);
return popBoolified();
}
handleLoop(node,
() {},
buildCondition,
() {},
() { visit(node.body); });
}
visitDoWhile(DoWhile node) {
LocalsHandler savedLocals = new LocalsHandler.from(localsHandler);
localsHandler.startLoop(node);
JumpHandler jumpHandler = beginLoopHeader(node);
HLoopInformation loopInfo = current.loopInformation;
HBasicBlock loopEntryBlock = current;
HBasicBlock bodyEntryBlock = current;
TargetElement target = elements[node];
bool hasContinues = target !== null && target.isContinueTarget;
if (hasContinues) {
// Add extra block to hang labels on.
// It doesn't currently work if they are on the same block as the
// HLoopInfo. The handling of HLabeledBlockInformation will visit a
// SubGraph that starts at the same block again, so the HLoopInfo is
// either handled twice, or it's handled after the labeled block info,
// both of which generate the wrong code.
// Using a separate block is just a simple workaround.
bodyEntryBlock = openNewBlock();
}
localsHandler.enterLoopBody(node);
hackAroundPossiblyAbortingBody(node, () { visit(node.body); });
// If there are no continues we could avoid the creation of the condition
// block. This could also lead to a block having multiple entries and exits.
HBasicBlock bodyExitBlock = close(new HGoto());
HBasicBlock conditionBlock = addNewBlock();
List<LocalsHandler> continueLocals = <LocalsHandler>[];
jumpHandler.forEachContinue((HContinue instruction, LocalsHandler locals) {
instruction.block.addSuccessor(conditionBlock);
continueLocals.add(locals);
});
bodyExitBlock.addSuccessor(conditionBlock);
if (!continueLocals.isEmpty()) {
continueLocals.add(localsHandler);
localsHandler = savedLocals.mergeMultiple(continueLocals, conditionBlock);
SubGraph bodyGraph = new SubGraph(bodyEntryBlock, bodyExitBlock);
List<LabelElement> labels = jumpHandler.labels();
HSubGraphBlockInformation bodyInfo =
new HSubGraphBlockInformation(bodyGraph);
HLabeledBlockInformation info;
if (!labels.isEmpty()) {
info = new HLabeledBlockInformation(bodyInfo, labels, isContinue: true);
} else {
info = new HLabeledBlockInformation.implicit(bodyInfo, target,
isContinue: true);
}
bodyEntryBlock.setBlockFlow(info, conditionBlock);
}
open(conditionBlock);
visit(node.condition);
assert(!isAborted());
HInstruction conditionInstruction = popBoolified();
HBasicBlock conditionEndBlock =
close(new HLoopBranch(conditionInstruction, HLoopBranch.DO_WHILE_LOOP));
conditionEndBlock.addSuccessor(loopEntryBlock); // The back-edge.
loopEntryBlock.postProcessLoopHeader();
endLoop(loopEntryBlock, conditionEndBlock, jumpHandler, localsHandler);
jumpHandler.close();
SubExpression conditionExpression =
new SubExpression(conditionBlock, conditionEndBlock);
SubGraph bodyGraph = new SubGraph(bodyEntryBlock, bodyExitBlock);
HLoopBlockInformation loopBlockInfo =
new HLoopBlockInformation(
HLoopBlockInformation.DO_WHILE_LOOP,
null,
wrapExpressionGraph(conditionExpression),
wrapStatementGraph(bodyGraph),
null,
loopEntryBlock.loopInformation.target,
loopEntryBlock.loopInformation.labels);
loopEntryBlock.setBlockFlow(loopBlockInfo, current);
loopInfo.loopBlockInformation = loopBlockInfo;
}
visitFunctionExpression(FunctionExpression node) {
ClosureData nestedClosureData = builder.closureDataCache[node];
if (nestedClosureData === null) {
// TODO(floitsch): we can only assume that the reason for not having a
// closure data here is, because the function is inside an initializer.
compiler.unimplemented("Closures inside initializers", node: node);
}
assert(nestedClosureData !== null);
assert(nestedClosureData.closureClassElement !== null);
ClassElement closureClassElement =
nestedClosureData.closureClassElement;
FunctionElement callElement = nestedClosureData.callElement;
// TODO(ahe): This should be registered in codegen, not here.
compiler.enqueuer.codegen.addToWorkList(callElement, elements);
// TODO(ahe): This should be registered in codegen, not here.
compiler.enqueuer.codegen.registerInstantiatedClass(closureClassElement);
assert(closureClassElement.members.isEmpty());
List<HInstruction> capturedVariables = <HInstruction>[];
for (Element member in closureClassElement.backendMembers) {
// The backendMembers also contains the call method(s). We are only
// interested in the fields.
if (member.kind == ElementKind.FIELD) {
Element capturedLocal = nestedClosureData.capturedFieldMapping[member];
assert(capturedLocal != null);
capturedVariables.add(localsHandler.readLocal(capturedLocal));
}
}
push(new HForeignNew(closureClassElement, capturedVariables));
}
visitFunctionDeclaration(FunctionDeclaration node) {
visit(node.function);
localsHandler.updateLocal(elements[node], pop());
}
visitIdentifier(Identifier node) {
if (node.isThis()) {
stack.add(localsHandler.readThis());
} else {
compiler.internalError("SsaBuilder.visitIdentifier on non-this",
node: node);
}
}
visitIf(If node) {
handleIf(node,
() => visit(node.condition),
() => visit(node.thenPart),
node.elsePart != null ? () => visit(node.elsePart) : null);
}
void handleIf(Node diagnosticNode,
void visitCondition(), void visitThen(), void visitElse()) {
SsaBranchBuilder branchBuilder = new SsaBranchBuilder(this, diagnosticNode);
branchBuilder.handleIf(visitCondition, visitThen, visitElse);
}
void visitLogicalAndOr(Send node, Operator op) {
handleLogicalAndOr(node,
() { visit(node.receiver); },
() { visit(node.argumentsNode); },
isAnd: (const SourceString("&&") == op.source));
}
void handleLogicalAndOr(Node diagnosticNode,
void left(), void right(), [bool isAnd = true]) {
// x && y is transformed into:
// t0 = boolify(x);
// if (t0) {
// t1 = boolify(y);
// } else {
// t2 = t0;
// }
// result = phi(t1, false);
//
// x || y is transformed into:
// t0 = boolify(x);
// if (not(t0)) {
// t1 = boolify(y);
// } else {
// t2 = t0;
// }
// result = phi(t1, true);
HInstruction boolifiedLeft;
HInstruction boolifiedRight;
void visitCondition() {
left();
boolifiedLeft = popBoolified();
HInstruction condition;
if (isAnd) {
condition = boolifiedLeft;
} else {
condition = new HNot(boolifiedLeft);
add(condition);
}
stack.add(condition);
}
void visitThen() {
right();
boolifiedRight = popBoolified();
}
handleIf(diagnosticNode, visitCondition, visitThen, null);
HPhi result = new HPhi.manyInputs(null,
<HInstruction>[boolifiedRight, graph.addConstantBool(!isAnd)]);
current.addPhi(result);
stack.add(result);
}
void visitLogicalNot(Send node) {
assert(node.argumentsNode is Prefix);
visit(node.receiver);
HNot not = new HNot(popBoolified());
push(not);
}
void visitUnary(Send node, Operator op) {
assert(node.argumentsNode is Prefix);
visit(node.receiver);
assert(op.token.kind !== PLUS_TOKEN);
HInstruction operand = pop();
HInstruction target =
new HStatic(interceptors.getPrefixOperatorInterceptor(op));
add(target);
HInvokeUnary result;
String value = op.source.stringValue;
switch (value) {
case "-": result = new HNegate(target, operand); break;
case "~": result = new HBitNot(target, operand); break;
default:
compiler.internalError('Unexpected unary operator: $value.', node: op);
break;
}
// See if we can constant-fold right away. This avoids rewrites later on.
if (operand is HConstant) {
HConstant constant = operand;
Constant folded = result.operation.fold(constant.constant);
if (folded !== null) {
stack.add(graph.addConstant(folded));
return;
}
}
push(result);
}
void visitBinary(HInstruction left, Operator op, HInstruction right) {
Element element = interceptors.getOperatorInterceptor(op);
assert(element != null);
HInstruction target = new HStatic(element);
add(target);
switch (op.source.stringValue) {
case "+":
case "++":
case "+=":
push(new HAdd(target, left, right));
break;
case "-":
case "--":
case "-=":
push(new HSubtract(target, left, right));
break;
case "*":
case "*=":
push(new HMultiply(target, left, right));
break;
case "/":
case "/=":
push(new HDivide(target, left, right));
break;
case "~/":
case "~/=":
push(new HTruncatingDivide(target, left, right));
break;
case "%":
case "%=":
push(new HModulo(target, left, right));
break;
case "<<":
case "<<=":
push(new HShiftLeft(target, left, right));
break;
case ">>":
case ">>=":
push(new HShiftRight(target, left, right));
break;
case "|":
case "|=":
push(new HBitOr(target, left, right));
break;
case "&":
case "&=":
push(new HBitAnd(target, left, right));
break;
case "^":
case "^=":
push(new HBitXor(target, left, right));
break;
case "==":
push(new HEquals(target, left, right));
break;
case "===":
push(new HIdentity(target, left, right));
break;
case "!==":
HIdentity eq = new HIdentity(target, left, right);
add(eq);
push(new HNot(eq));
break;
case "<":
push(new HLess(target, left, right));
break;
case "<=":
push(new HLessEqual(target, left, right));
break;
case ">":
push(new HGreater(target, left, right));
break;
case ">=":
push(new HGreaterEqual(target, left, right));
break;
case "!=":
HEquals eq = new HEquals(target, left, right);
add(eq);
HBoolify bl = new HBoolify(eq);
add(bl);
push(new HNot(bl));
break;
default: compiler.unimplemented("SsaBuilder.visitBinary");
}
}
HInstruction generateInstanceSendReceiver(Send send) {
assert(Elements.isInstanceSend(send, elements));
if (send.receiver == null) {
return localsHandler.readThis();
}
visit(send.receiver);
return pop();
}
void generateInstanceGetterWithCompiledReceiver(Send send,
HInstruction receiver) {
assert(Elements.isInstanceSend(send, elements));
SourceString getterName = send.selector.asIdentifier().source;
Selector selector = elements.getSelector(send);
Element staticInterceptor = null;
if (methodInterceptionEnabled) {
staticInterceptor = interceptors.getStaticGetInterceptor(getterName);
}
if (staticInterceptor != null) {
HStatic target = new HStatic(staticInterceptor);
add(target);
List<HInstruction> inputs = <HInstruction>[target, receiver];
push(new HInvokeInterceptor(selector, getterName, inputs, getter: true));
} else {
push(new HInvokeDynamicGetter(selector, null, getterName, receiver));
}
}
void generateGetter(Send send, Element element) {
if (Elements.isStaticOrTopLevelField(element)) {
if (element.kind == ElementKind.FIELD && !element.isAssignable()) {
// A static final. Get its constant value and inline it.
Constant value = compiler.constantHandler.compileVariable(element);
stack.add(graph.addConstant(value));
} else {
Selector selector = elements.getSelector(send);
push(new HStatic(element));
if (element.kind == ElementKind.GETTER) {
push(new HInvokeStatic(selector, <HInstruction>[pop()]));
}
}
} else if (Elements.isInstanceSend(send, elements)) {
HInstruction receiver = generateInstanceSendReceiver(send);
generateInstanceGetterWithCompiledReceiver(send, receiver);
} else if (Elements.isStaticOrTopLevelFunction(element)) {
push(new HStatic(element));
// TODO(ahe): This should be registered in codegen.
compiler.enqueuer.codegen.registerGetOfStaticFunction(element);
} else {
stack.add(localsHandler.readLocal(element));
}
}
void generateInstanceSetterWithCompiledReceiver(Send send,
HInstruction receiver,
HInstruction value) {
assert(Elements.isInstanceSend(send, elements));
SourceString dartSetterName = send.selector.asIdentifier().source;
Selector selector = elements.getSelector(send);
Element staticInterceptor = null;
if (methodInterceptionEnabled) {
staticInterceptor = interceptors.getStaticSetInterceptor(dartSetterName);
}
if (staticInterceptor != null) {
HStatic target = new HStatic(staticInterceptor);
add(target);
List<HInstruction> inputs = <HInstruction>[target, receiver, value];
add(new HInvokeInterceptor(
selector, dartSetterName, inputs, setter: true));
} else {
add(new HInvokeDynamicSetter(selector, null, dartSetterName,
receiver, value));
}
stack.add(value);
}
void generateSetter(SendSet send, Element element, HInstruction value) {
if (Elements.isStaticOrTopLevelField(element)) {
Selector selector = elements.getSelector(send);
if (element.kind == ElementKind.SETTER) {
HStatic target = new HStatic(element);
add(target);
add(new HInvokeStatic(selector, <HInstruction>[target, value]));
} else {
add(new HStaticStore(element, value));
}
stack.add(value);
} else if (element === null || Elements.isInstanceField(element)) {
HInstruction receiver = generateInstanceSendReceiver(send);
generateInstanceSetterWithCompiledReceiver(send, receiver, value);
} else {
stack.add(value);
// If the value does not already have a name, give it here.
if (value.sourceElement === null) {
value.sourceElement = element;
}
HInstruction checked = potentiallyCheckType(value, element);
if (checked !== value) {
pop();
stack.add(checked);
}
localsHandler.updateLocal(element, checked);
}
}
visitOperatorSend(node) {
assert(node.selector is Operator);
if (!methodInterceptionEnabled) {
visitDynamicSend(node);
return;
}
Operator op = node.selector;
if (const SourceString("[]") == op.source) {
HStatic target = new HStatic(interceptors.getIndexInterceptor());
add(target);
visit(node.receiver);
HInstruction receiver = pop();
visit(node.argumentsNode);
HInstruction index = pop();
push(new HIndex(target, receiver, index));
} else if (const SourceString("&&") == op.source ||
const SourceString("||") == op.source) {
visitLogicalAndOr(node, op);
} else if (const SourceString("!") == op.source) {
visitLogicalNot(node);
} else if (node.argumentsNode is Prefix) {
visitUnary(node, op);
} else if (const SourceString("is") == op.source) {
visit(node.receiver);
HInstruction expression = pop();
Node argument = node.arguments.head;
TypeAnnotation typeAnnotation = argument.asTypeAnnotation();
bool isNot = false;
// TODO(ngeoffray): Duplicating pattern in resolver. We should
// add a new kind of node.
if (typeAnnotation == null) {
typeAnnotation = argument.asSend().receiver;
isNot = true;
}
Type type = elements.getType(typeAnnotation);
HInstruction typeInfo = null;
if (compiler.codegenWorld.rti.hasTypeArguments(type)) {
HInstruction typeInfoGetter =
new HStatic(interceptors.getGetRuntimeTypeInfo());
add(typeInfoGetter);
typeInfo = new HInvokeStatic(Selector.INVOCATION_1,
<HInstruction>[typeInfoGetter,
expression]);
add(typeInfo);
}
if (type.element.kind === ElementKind.TYPE_VARIABLE) {
// TODO(karlklose): We emulate the frog behavior and answer
// true to any is check involving a type variable -- both is T
// and is !T -- until we have a proper implementation of
// reified generics.
stack.add(graph.addConstantBool(true));
} else {
HInstruction instruction;
if (typeInfo !== null) {
instruction = new HIs.withTypeInfoCall(type, expression, typeInfo);
} else {
instruction = new HIs(type, expression);
}
if (isNot) {
add(instruction);
instruction = new HNot(instruction);
}
push(instruction);
}
} else if (const SourceString("as") == op.source) {
visit(node.receiver);
HInstruction expression = pop();
Node argument = node.arguments.head;
TypeAnnotation typeAnnotation = argument.asTypeAnnotation();
Type type = elements.getType(typeAnnotation);
HInstruction converted = convertType(expression, type.element,
HTypeConversion.CAST_TYPE_CHECK);
stack.add(converted);
} else {
visit(node.receiver);
visit(node.argumentsNode);
var right = pop();
var left = pop();
visitBinary(left, op, right);
}
}
void addDynamicSendArgumentsToList(Send node, List<HInstruction> list) {
Selector selector = elements.getSelector(node);
if (selector.namedArgumentCount == 0) {
addGenericSendArgumentsToList(node.arguments, list);
} else {
// Visit positional arguments and add them to the list.
Link<Node> arguments = node.arguments;
int positionalArgumentCount = selector.positionalArgumentCount;
for (int i = 0;
i < positionalArgumentCount;
arguments = arguments.tail, i++) {
visit(arguments.head);
list.add(pop());
}
// Visit named arguments and add them into a temporary map.
Map<SourceString, HInstruction> instructions =
new Map<SourceString, HInstruction>();
List<SourceString> namedArguments = selector.namedArguments;
int nameIndex = 0;
for (; !arguments.isEmpty(); arguments = arguments.tail) {
visit(arguments.head);
instructions[namedArguments[nameIndex++]] = pop();
}
// Iterate through the named arguments to add them to the list
// of instructions, in an order that can be shared with
// selectors with the same named arguments.
List<SourceString> orderedNames = selector.getOrderedNamedArguments();
for (SourceString name in orderedNames) {
list.add(instructions[name]);
}
}
}
/**
* Returns true if the arguments were compatible with the function signature.
*/
bool addStaticSendArgumentsToList(Selector selector,
Link<Node> arguments,
FunctionElement element,
List<HInstruction> list) {
HInstruction compileArgument(Node argument) {
visit(argument);
return pop();
}
HInstruction compileConstant(Element constantElement) {
Constant constant = compiler.compileVariable(constantElement);
return graph.addConstant(constant);
}
return selector.addArgumentsToList(arguments,
list,
element,
compileArgument,
compileConstant,
compiler);
}
void addGenericSendArgumentsToList(Link<Node> link, List<HInstruction> list) {
for (; !link.isEmpty(); link = link.tail) {
visit(link.head);
list.add(pop());
}
}
visitDynamicSend(Send node) {
Selector selector = elements.getSelector(node);
var inputs = <HInstruction>[];
SourceString dartMethodName;
bool isNotEquals = false;
if (node.isIndex && !node.arguments.tail.isEmpty()) {
dartMethodName = Elements.constructOperatorName(
const SourceString('operator'),
const SourceString('[]='));
} else if (node.selector.asOperator() != null) {
SourceString name = node.selector.asIdentifier().source;
isNotEquals = name.stringValue === '!=';
dartMethodName = Elements.constructOperatorName(
const SourceString('operator'),
name,
node.argumentsNode is Prefix);
} else {
dartMethodName = node.selector.asIdentifier().source;
}
Element interceptor = null;
if (methodInterceptionEnabled && node.receiver !== null) {
interceptor = interceptors.getStaticInterceptor(dartMethodName,
node.argumentCount());
}
if (interceptor != null) {
HStatic target = new HStatic(interceptor);
add(target);
inputs.add(target);
visit(node.receiver);
inputs.add(pop());
addGenericSendArgumentsToList(node.arguments, inputs);
push(new HInvokeInterceptor(selector, dartMethodName, inputs));
return;
}
if (node.receiver === null) {
inputs.add(localsHandler.readThis());
} else {
visit(node.receiver);
inputs.add(pop());
}
addDynamicSendArgumentsToList(node, inputs);
// The first entry in the inputs list is the receiver.
push(new HInvokeDynamicMethod(selector, dartMethodName, inputs));
if (isNotEquals) {
HNot not = new HNot(popBoolified());
push(not);
}
}
visitClosureSend(Send node) {
Selector selector = elements.getSelector(node);
assert(node.receiver === null);
Element element = elements[node];
HInstruction closureTarget;
if (element === null) {
visit(node.selector);
closureTarget = pop();
} else {
assert(Elements.isLocal(element));
closureTarget = localsHandler.readLocal(element);
}
var inputs = <HInstruction>[];
inputs.add(closureTarget);
addDynamicSendArgumentsToList(node, inputs);
push(new HInvokeClosure(selector, inputs));
}
void handleForeignJs(Send node) {
Link<Node> link = node.arguments;
// If the invoke is on foreign code, don't visit the first
// argument, which is the type, and the second argument,
// which is the foreign code.
if (link.isEmpty() || link.isEmpty()) {
compiler.cancel('At least two arguments expected',
node: node.argumentsNode);
}
link = link.tail.tail;
List<HInstruction> inputs = <HInstruction>[];
addGenericSendArgumentsToList(link, inputs);
Node type = node.arguments.head;
Node literal = node.arguments.tail.head;
if (literal is !StringNode || literal.dynamic.isInterpolation) {
compiler.cancel('JS code must be a string literal', node: literal);
}
if (type is !LiteralString) {
compiler.cancel(
'The type of a JS expression must be a string literal', node: type);
}
push(new HForeign(
literal.dynamic.dartString, type.dynamic.dartString, inputs));
}
void handleForeignUnintercepted(Send node) {
Link<Node> link = node.arguments;
if (!link.tail.isEmpty()) {
compiler.cancel(
'More than one expression in UNINTERCEPTED()', node: node);
}
Expression expression = link.head;
disableMethodInterception();
visit(expression);
enableMethodInterception();
}
void handleForeignJsHasEquals(Send node) {
List<HInstruction> inputs = <HInstruction>[];
if (!node.arguments.tail.isEmpty()) {
compiler.cancel(
'More than one expression in JS_HAS_EQUALS()', node: node);
}
addGenericSendArgumentsToList(node.arguments, inputs);
String name = compiler.namer.instanceMethodName(
currentLibrary, Elements.OPERATOR_EQUALS, 1);
push(new HForeign(new DartString.literal('!!#.$name'),
const LiteralDartString('bool'),
inputs));
}
void handleForeignJsCurrentIsolate(Send node) {
if (!node.arguments.isEmpty()) {
compiler.cancel(
'Too many arguments to JS_CURRENT_ISOLATE', node: node);
}
if (!compiler.hasIsolateSupport()) {
// If the isolate library is not used, we just generate code
// to fetch the Leg's current isolate.
String name = compiler.namer.CURRENT_ISOLATE;
push(new HForeign(new DartString.literal(name),
const LiteralDartString('var'),
<HInstruction>[]));
} else {
// Call a helper method from the isolate library. The isolate
// library uses its own isolate structure, that encapsulates
// Leg's isolate.
Element element = compiler.isolateLibrary.find(
const SourceString('_currentIsolate'));
if (element === null) {
compiler.cancel(
'Isolate library and compiler mismatch', node: node);
}
HStatic target = new HStatic(element);
add(target);
push(new HInvokeStatic(Selector.INVOCATION_0,
<HInstruction>[target]));
}
}
void handleForeignJsCallInIsolate(Send node) {
Link<Node> link = node.arguments;
if (!compiler.hasIsolateSupport()) {
// If the isolate library is not used, we just invoke the
// closure.
visit(link.tail.head);
push(new HInvokeClosure(Selector.INVOCATION_0,
<HInstruction>[pop()]));
} else {
// Call a helper method from the isolate library.
Element element = compiler.isolateLibrary.find(
const SourceString('_callInIsolate'));
if (element === null) {
compiler.cancel(
'Isolate library and compiler mismatch', node: node);
}
HStatic target = new HStatic(element);
add(target);
List<HInstruction> inputs = <HInstruction>[target];
addGenericSendArgumentsToList(link, inputs);
push(new HInvokeStatic(Selector.INVOCATION_0, inputs));
}
}
void handleForeignDartClosureToJs(Send node) {
if (node.arguments.isEmpty() || !node.arguments.tail.isEmpty()) {
compiler.cancel('Exactly one argument required',
node: node.argumentsNode);
}
Node closure = node.arguments.head;
Element element = elements[closure];
if (!Elements.isStaticOrTopLevelFunction(element)) {
compiler.cancel(
'JS_TO_CLOSURE requires a static or top-level method',
node: closure);
}
FunctionElement function = element;
FunctionSignature params = function.computeSignature(compiler);
if (params.optionalParameterCount !== 0) {
compiler.cancel(
'JS_TO_CLOSURE does not handle closure with optional parameters',
node: closure);
}
visit(closure);
List<HInstruction> inputs = <HInstruction>[pop()];
String invocationName = compiler.namer.closureInvocationName(
new Selector(SelectorKind.INVOCATION, params.requiredParameterCount));
push(new HForeign(new DartString.literal('#.$invocationName'),
const LiteralDartString('var'),
inputs));
}
visitForeignSend(Send node) {
Element element = elements[node];
if (element.name == const SourceString('JS')) {
handleForeignJs(node);
} else if (element.name == const SourceString('UNINTERCEPTED')) {
handleForeignUnintercepted(node);
} else if (element.name == const SourceString('JS_HAS_EQUALS')) {
handleForeignJsHasEquals(node);
} else if (element.name == const SourceString('JS_CURRENT_ISOLATE')) {
handleForeignJsCurrentIsolate(node);
} else if (element.name == const SourceString('JS_CALL_IN_ISOLATE')) {
handleForeignJsCallInIsolate(node);
} else if (element.name == const SourceString('DART_CLOSURE_TO_JS')) {
handleForeignDartClosureToJs(node);
} else {
throw "Unknown foreign: ${node.selector}";
}
}
generateSuperNoSuchMethodSend(Send node) {
ClassElement cls = work.element.getEnclosingClass();
Element element = cls.lookupSuperMember(Compiler.NO_SUCH_METHOD);
HStatic target = new HStatic(element);
add(target);
HInstruction self = localsHandler.readThis();
Identifier identifier = node.selector.asIdentifier();
String name = identifier.source.slowToString();
// TODO(ahe): Add the arguments to this list.
push(new HLiteralList([]));
var inputs = <HInstruction>[
target,
self,
graph.addConstantString(new DartString.literal(name), node),
pop()];
push(new HInvokeSuper(Selector.INVOCATION_2, inputs));
}
visitSend(Send node) {
Element element = elements[node];
if (element !== null && element === work.element) {
graph.isRecursiveMethod = true;
}
super.visitSend(node);
}
visitSuperSend(Send node) {
Selector selector = elements.getSelector(node);
Element element = elements[node];
if (element === null) return generateSuperNoSuchMethodSend(node);
HInstruction target = new HStatic(element);
HInstruction context = localsHandler.readThis();
add(target);
var inputs = <HInstruction>[target, context];
if (node.isPropertyAccess) {
push(new HInvokeSuper(selector, inputs));
} else if (element.kind == ElementKind.FUNCTION ||
element.kind == ElementKind.GENERATIVE_CONSTRUCTOR) {
bool succeeded = addStaticSendArgumentsToList(selector, node.arguments,
element, inputs);
if (!succeeded) {
// TODO(ngeoffray): Match the VM behavior and throw an
// exception at runtime.
compiler.cancel('Unimplemented non-matching static call', node);
}
push(new HInvokeSuper(selector, inputs));
} else {
target = new HInvokeSuper(Selector.GETTER, inputs);
add(target);
inputs = <HInstruction>[target];
addDynamicSendArgumentsToList(node, inputs);
push(new HInvokeClosure(selector, inputs));
}
}
visitNewSend(Send node) {
computeType(element) {
Element originalElement = elements[node];
if (originalElement.enclosingElement === compiler.listClass) {
if (node.arguments.isEmpty()) {
return HType.EXTENDABLE_ARRAY;
} else {
return HType.MUTABLE_ARRAY;
}
} else if (element.isGenerativeConstructor()) {
ClassElement cls = element.enclosingElement;
return new HBoundedType.exact(cls.type);
} else {
return HType.UNKNOWN;
}
}
Selector selector = elements.getSelector(node);
Element element = elements[node];
if (compiler.enqueuer.resolution.getCachedElements(element) === null) {
compiler.internalError("Unresolved element: $element", node: node);
}
FunctionElement functionElement = element;
element = functionElement.defaultImplementation;
HInstruction target = new HStatic(element);
add(target);
var inputs = <HInstruction>[];
inputs.add(target);
bool succeeded = addStaticSendArgumentsToList(selector, node.arguments,
element, inputs);
if (!succeeded) {
// TODO(ngeoffray): Match the VM behavior and throw an
// exception at runtime.
compiler.cancel('Unimplemented non-matching static call', node: node);
}
HType elementType = computeType(element);
HInstruction newInstance = new HInvokeStatic(selector, inputs, elementType);
push(newInstance);
TypeAnnotation annotation = getTypeAnnotationFromSend(node);
Type type = elements.getType(annotation);
generateSetRuntimeTypeInformation(newInstance, type);
}
generateSetRuntimeTypeInformation(HInstruction instance, Type type) {
if (compiler.codegenWorld.rti.hasTypeArguments(type)) {
String typeString = compiler.codegenWorld.rti.asJsString(type);
HInstruction typeInfo = new HForeign(new LiteralDartString(typeString),
new LiteralDartString('Object'),
<HInstruction>[]);
add(typeInfo);
HInstruction typeInfoSetter =
new HStatic(interceptors.getSetRuntimeTypeInfo());
add(typeInfoSetter);
Selector setSelector = Selector.INVOCATION_2;
var inputs = <HInstruction>[typeInfoSetter, instance, typeInfo];
add(new HInvokeStatic(setSelector, inputs));
}
}
visitStaticSend(Send node) {
Selector selector = elements.getSelector(node);
Element element = elements[node];
if (element === compiler.assertMethod && !compiler.enableUserAssertions) {
stack.add(graph.addConstantNull());
return;
}
compiler.ensure(element.kind !== ElementKind.GENERATIVE_CONSTRUCTOR);
HInstruction target = new HStatic(element);
add(target);
var inputs = <HInstruction>[];
inputs.add(target);
if (element.kind == ElementKind.FUNCTION) {
bool succeeded = addStaticSendArgumentsToList(selector, node.arguments,
element, inputs);
if (!succeeded) {
// TODO(ngeoffray): Match the VM behavior and throw an
// exception at runtime.
compiler.cancel('Unimplemented non-matching static call', node: node);
}
push(new HInvokeStatic(selector, inputs));
} else {
if (element.kind == ElementKind.GETTER) {
target = new HInvokeStatic(Selector.GETTER, inputs);
add(target);
inputs = <HInstruction>[target];
}
addDynamicSendArgumentsToList(node, inputs);
push(new HInvokeClosure(selector, inputs));
}
}
visitGetterSend(Send node) {
generateGetter(node, elements[node]);
}
// TODO(antonm): migrate rest of SsaBuilder to internalError.
internalError(String reason, [Node node]) {
compiler.internalError(reason, node: node);
}
// TODO(karlklose): share with resolver.
TypeAnnotation getTypeAnnotationFromSend(Send send) {
if (send.selector is TypeAnnotation) {
return send.selector;
} else if (send.selector is Send) {
Send selector = send.selector;
if (selector.receiver is TypeAnnotation) {
return selector.receiver;
}
} else {
compiler.internalError("malformed send in new expression");
}
}
visitNewExpression(NewExpression node) {
if (node.isConst()) {
// TODO(karlklose): add type representation
ConstantHandler handler = compiler.constantHandler;
Constant constant = handler.compileNodeWithDefinitions(node, elements);
stack.add(graph.addConstant(constant));
} else {
visitNewSend(node.send);
}
}
visitSendSet(SendSet node) {
Operator op = node.assignmentOperator;
if (node.isSuperCall) {
Selector selector = elements.getSelector(node);
Element element = elements[node];
if (element === null) return generateSuperNoSuchMethodSend(node);
HInstruction target = new HStatic(element);
HInstruction context = localsHandler.readThis();
add(target);
var inputs = <HInstruction>[target, context];
addDynamicSendArgumentsToList(node, inputs);
push(new HInvokeSuper(selector, inputs));
} else if (node.isIndex) {
if (!methodInterceptionEnabled) {
assert(op.source.stringValue === '=');
visitDynamicSend(node);
} else {
HStatic target = new HStatic(
interceptors.getIndexAssignmentInterceptor());
add(target);
visit(node.receiver);
HInstruction receiver = pop();
visit(node.argumentsNode);
if (const SourceString("=") == op.source) {
HInstruction value = pop();
HInstruction index = pop();
add(new HIndexAssign(target, receiver, index, value));
stack.add(value);
} else {
HInstruction value;
HInstruction index;
bool isCompoundAssignment = op.source.stringValue.endsWith('=');
// Compound assignments are considered as being prefix.
bool isPrefix = !node.isPostfix;
Element getter = elements[node.selector];
if (isCompoundAssignment) {
value = pop();
index = pop();
} else {
index = pop();
value = graph.addConstantInt(1);
}
HStatic indexMethod = new HStatic(interceptors.getIndexInterceptor());
add(indexMethod);
HInstruction left = new HIndex(indexMethod, receiver, index);
add(left);
Element opElement = elements[op];
visitBinary(left, op, value);
value = pop();
HInstruction assign = new HIndexAssign(
target, receiver, index, value);
add(assign);
if (isPrefix) {
stack.add(value);
} else {
stack.add(left);
}
}
}
} else if (const SourceString("=") == op.source) {
Element element = elements[node];
Link<Node> link = node.arguments;
assert(!link.isEmpty() && link.tail.isEmpty());
visit(link.head);
HInstruction value = pop();
generateSetter(node, element, value);
} else if (op.source.stringValue === "is") {
compiler.internalError("is-operator as SendSet", node: op);
} else {
assert(const SourceString("++") == op.source ||
const SourceString("--") == op.source ||
node.assignmentOperator.source.stringValue.endsWith("="));
Element element = elements[node];
bool isCompoundAssignment = !node.arguments.isEmpty();
bool isPrefix = !node.isPostfix; // Compound assignments are prefix.
// [receiver] is only used if the node is an instance send.
HInstruction receiver = null;
if (Elements.isInstanceSend(node, elements)) {
receiver = generateInstanceSendReceiver(node);
generateInstanceGetterWithCompiledReceiver(node, receiver);
} else {
generateGetter(node, elements[node.selector]);
}
HInstruction left = pop();
HInstruction right;
if (isCompoundAssignment) {
visit(node.argumentsNode);
right = pop();
} else {
right = graph.addConstantInt(1);
}
visitBinary(left, op, right);
HInstruction operation = pop();
assert(operation !== null);
if (Elements.isInstanceSend(node, elements)) {
assert(receiver !== null);
generateInstanceSetterWithCompiledReceiver(node, receiver, operation);
} else {
assert(receiver === null);
generateSetter(node, element, operation);
}
if (!isPrefix) {
pop();
stack.add(left);
}
}
}
void visitLiteralInt(LiteralInt node) {
stack.add(graph.addConstantInt(node.value));
}
void visitLiteralDouble(LiteralDouble node) {
stack.add(graph.addConstantDouble(node.value));
}
void visitLiteralBool(LiteralBool node) {
stack.add(graph.addConstantBool(node.value));
}
void visitLiteralString(LiteralString node) {
stack.add(graph.addConstantString(node.dartString, node));
}
void visitStringJuxtaposition(StringJuxtaposition node) {
if (!node.isInterpolation) {
// This is a simple string with no interpolations.
stack.add(graph.addConstantString(node.dartString, node));
return;
}
StringBuilderVisitor stringBuilder = new StringBuilderVisitor(this, node);
stringBuilder.visit(node);
stack.add(stringBuilder.result);
}
void visitLiteralNull(LiteralNull node) {
stack.add(graph.addConstantNull());
}
visitNodeList(NodeList node) {
for (Link<Node> link = node.nodes; !link.isEmpty(); link = link.tail) {
if (isAborted()) {
compiler.reportWarning(link.head, 'dead code');
} else {
visit(link.head);
}
}
}
void visitParenthesizedExpression(ParenthesizedExpression node) {
visit(node.expression);
}
visitOperator(Operator node) {
// Operators are intercepted in their surrounding Send nodes.
compiler.internalError('visitOperator should not be called', node: node);
}
visitCascade(Cascade node) {
visit(node.expression);
// Remove the result and reveal the duplicated receiver on the stack.
pop();
}
visitCascadeReceiver(CascadeReceiver node) {
visit(node.expression);
dup();
}
visitReturn(Return node) {
if (node.getBeginToken().stringValue === 'native') {
native.handleSsaNative(this, node.expression);
return;
}
HInstruction value;
if (node.expression === null) {
value = graph.addConstantNull();
} else {
visit(node.expression);
value = pop();
}
close(new HReturn(value)).addSuccessor(graph.exit);
}
visitThrow(Throw node) {
if (node.expression === null) {
HInstruction exception = rethrowableException;
if (exception === null) {
exception = graph.addConstantNull();
compiler.reportError(node,
'throw without expression outside catch block');
}
close(new HThrow(exception, isRethrow: true));
} else {
visit(node.expression);
close(new HThrow(pop()));
}
}
visitTypeAnnotation(TypeAnnotation node) {
compiler.internalError('visiting type annotation in SSA builder',
node: node);
}
visitVariableDefinitions(VariableDefinitions node) {
for (Link<Node> link = node.definitions.nodes;
!link.isEmpty();
link = link.tail) {
Node definition = link.head;
if (definition is Identifier) {
HInstruction initialValue = graph.addConstantNull();
localsHandler.updateLocal(elements[definition], initialValue);
} else {
assert(definition is SendSet);
visitSendSet(definition);
pop(); // Discard value.
}
}
}
visitLiteralList(LiteralList node) {
if (node.isConst()) {
ConstantHandler handler = compiler.constantHandler;
Constant constant = handler.compileNodeWithDefinitions(node, elements);
stack.add(graph.addConstant(constant));
return;
}
List<HInstruction> inputs = <HInstruction>[];
for (Link<Node> link = node.elements.nodes;
!link.isEmpty();
link = link.tail) {
visit(link.head);
inputs.add(pop());
}
push(new HLiteralList(inputs));
}
visitConditional(Conditional node) {
SsaBranchBuilder brancher =
new SsaBranchBuilder(this, diagnosticNode: node);
brancher.handleConditional(() => visit(node.condition),
() => visit(node.thenExpression),
() => visit(node.elseExpression));
}
visitStringInterpolation(StringInterpolation node) {
StringBuilderVisitor stringBuilder = new StringBuilderVisitor(this, node);
stringBuilder.visit(node);
stack.add(stringBuilder.result);
}
visitStringInterpolationPart(StringInterpolationPart node) {
// The parts are iterated in visitStringInterpolation.
compiler.internalError('visitStringInterpolation should not be called',
node: node);
}
visitEmptyStatement(EmptyStatement node) {
// Do nothing, empty statement.
}
visitModifiers(Modifiers node) {
compiler.unimplemented('SsaBuilder.visitModifiers', node: node);
}
visitBreakStatement(BreakStatement node) {
assert(!isAborted());
TargetElement target = elements[node];
assert(target !== null);
JumpHandler handler = jumpTargets[target];
assert(handler !== null);
if (node.target === null) {
handler.generateBreak();
} else {
LabelElement label = elements[node.target];
handler.generateBreak(label);
}
}
visitContinueStatement(ContinueStatement node) {
TargetElement target = elements[node];
assert(target !== null);
JumpHandler handler = jumpTargets[target];
assert(handler !== null);
if (node.target === null) {
handler.generateContinue();
} else {
LabelElement label = elements[node.target];
assert(label !== null);
handler.generateContinue(label);
}
}
/**
* Creates a [JumpHandler] for a statement. The node must be a jump
* target. If there are no breaks or continues targeting the statement,
* a special "null handler" is returned.
*/
JumpHandler createJumpHandler(Statement node) {
TargetElement element = elements[node];
if (element === null || element.statement !== node) {
// No breaks or continues to this node.
return new NullJumpHandler(compiler);
}
return new JumpHandler(this, element);
}
visitForIn(ForIn node) {
// Generate a structure equivalent to:
// Iterator<E> $iter = <iterable>.iterator()
// while ($iter.hasNext()) {
// E <declaredIdentifier> = $iter.next();
// <body>
// }
// All the generated calls are to zero-argument functions.
Selector selector = Selector.INVOCATION_0;
// The iterator is shared between initializer, condition and body.
HInstruction iterator;
void buildInitializer() {
SourceString iteratorName = const SourceString("iterator");
Element interceptor = interceptors.getStaticInterceptor(iteratorName, 0);
assert(interceptor != null);
HStatic target = new HStatic(interceptor);
add(target);
visit(node.expression);
List<HInstruction> inputs = <HInstruction>[target, pop()];
iterator = new HInvokeInterceptor(selector, iteratorName, inputs);
add(iterator);
}
HInstruction buildCondition() {
push(new HInvokeDynamicMethod(
selector, const SourceString('hasNext'), <HInstruction>[iterator]));
return popBoolified();
}
void buildBody() {
push(new HInvokeDynamicMethod(
selector, const SourceString('next'), <HInstruction>[iterator]));
Element variable;
if (node.declaredIdentifier.asSend() !== null) {
variable = elements[node.declaredIdentifier];
} else {
assert(node.declaredIdentifier.asVariableDefinitions() !== null);
VariableDefinitions variableDefinitions = node.declaredIdentifier;
variable = elements[variableDefinitions.definitions.nodes.head];
}
localsHandler.updateLocal(variable, pop());
visit(node.body);
}
handleLoop(node, buildInitializer, buildCondition, () {}, buildBody);
}
visitLabel(Label node) {
compiler.internalError('SsaBuilder.visitLabel', node: node);
}
visitLabeledStatement(LabeledStatement node) {
Statement body = node.statement;
if (body is Loop || body is SwitchStatement) {
// Loops and switches handle their own labels.
visit(body);
return;
}
// Non-loop statements can only be break targets, not continue targets.
TargetElement targetElement = elements[body];
if (targetElement === null || targetElement.statement !== body) {
// Labeled statements with no element on the body have no breaks.
// A different target statement only happens if the body is itself
// a break or continue for a different target. In that case, this
// label is also always unused.
visit(body);
return;
}
LocalsHandler beforeLocals = new LocalsHandler.from(localsHandler);
assert(targetElement.isBreakTarget);
JumpHandler handler = new JumpHandler(this, targetElement);
// Introduce a new basic block.
HBasicBlock entryBlock = openNewBlock();
hackAroundPossiblyAbortingBody(node, () { visit(body); });
SubGraph bodyGraph = new SubGraph(entryBlock, lastOpenedBlock);
HBasicBlock joinBlock = graph.addNewBlock();
List<LocalsHandler> breakLocals = <LocalsHandler>[];
handler.forEachBreak((HBreak breakInstruction, LocalsHandler locals) {
breakInstruction.block.addSuccessor(joinBlock);
breakLocals.add(locals);
});
bool hasBreak = breakLocals.length > 0;
if (!isAborted()) {
goto(current, joinBlock);
breakLocals.add(localsHandler);
}
open(joinBlock);
localsHandler = beforeLocals.mergeMultiple(breakLocals, joinBlock);
if (hasBreak) {
// There was at least one reachable break, so the label is needed.
entryBlock.setBlockFlow(
new HLabeledBlockInformation(new HSubGraphBlockInformation(bodyGraph),
handler.labels()),
joinBlock);
}
handler.close();
}
visitLiteralMap(LiteralMap node) {
if (node.isConst()) {
ConstantHandler handler = compiler.constantHandler;
Constant constant = handler.compileNodeWithDefinitions(node, elements);
stack.add(graph.addConstant(constant));
return;
}
List<HInstruction> inputs = <HInstruction>[];
for (Link<Node> link = node.entries.nodes;
!link.isEmpty();
link = link.tail) {
visit(link.head);
inputs.addLast(pop());
inputs.addLast(pop());
}
HLiteralList keyValuePairs = new HLiteralList(inputs);
HStatic mapMaker = new HStatic(interceptors.getMapMaker());
add(keyValuePairs);
add(mapMaker);
inputs = <HInstruction>[mapMaker, keyValuePairs];
// TODO(ngeoffray): give the concrete type of our map literal.
push(new HInvokeStatic(Selector.INVOCATION_1, inputs, HType.UNKNOWN));
}
visitLiteralMapEntry(LiteralMapEntry node) {
visit(node.value);
visit(node.key);
}
visitNamedArgument(NamedArgument node) {
visit(node.expression);
}
visitSwitchStatement(SwitchStatement node) {
if (tryBuildConstantSwitch(node)) return;
LocalsHandler savedLocals = new LocalsHandler.from(localsHandler);
HBasicBlock startBlock = openNewBlock();
visit(node.expression);
HInstruction expression = pop();
if (node.cases.isEmpty()) {
return;
}
Link<Node> cases = node.cases.nodes;
JumpHandler jumpHandler = createJumpHandler(node);
buildSwitchCases(cases, expression);
HBasicBlock lastBlock = lastOpenedBlock;
// Create merge block for break targets.
HBasicBlock joinBlock = new HBasicBlock();
List<LocalsHandler> caseLocals = <LocalsHandler>[];
jumpHandler.forEachBreak((HBreak instruction, LocalsHandler locals) {
instruction.block.addSuccessor(joinBlock);
caseLocals.add(locals);
});
if (!isAborted()) {
// The current flow is only aborted if the switch has a default that
// aborts (all previous cases must abort, and if there is no default,
// it's possible to miss all the cases).
caseLocals.add(localsHandler);
goto(current, joinBlock);
}
if (caseLocals.length != 0) {
graph.addBlock(joinBlock);
open(joinBlock);
if (caseLocals.length == 1) {
localsHandler = caseLocals[0];
} else {
localsHandler = savedLocals.mergeMultiple(caseLocals, joinBlock);
}
} else {
// The joinblock is not used.
joinBlock = null;
}
startBlock.setBlockFlow(
new HLabeledBlockInformation.implicit(
new HSubGraphBlockInformation(new SubGraph(startBlock, lastBlock)),
elements[node]),
joinBlock);
jumpHandler.close();
}
bool tryBuildConstantSwitch(SwitchStatement node) {
Map<CaseMatch, Constant> constants = new Map<CaseMatch, Constant>();
// First check whether all case expressions are compile-time constants.
for (SwitchCase switchCase in node.cases) {
for (Node labelOrCase in switchCase.labelsAndCases) {
if (labelOrCase is CaseMatch) {
CaseMatch match = labelOrCase;
Constant constant =
compiler.constantHandler.tryCompileNodeWithDefinitions(
match.expression, elements);
if (constant === null) return false;
constants[labelOrCase] = constant;
} else {
// We don't handle labels yet.
return false;
}
}
}
// TODO(ngeoffray): Handle switch-instruction in bailout code.
work.allowSpeculativeOptimization = false;
// Then build a switch structure.
HBasicBlock expressionStart = openNewBlock();
visit(node.expression);
HInstruction expression = pop();
if (node.cases.isEmpty()) {
return true;
}
HBasicBlock expressionEnd = current;
HSwitch switchInstruction = new HSwitch(<HInstruction>[expression]);
HBasicBlock expressionBlock = close(switchInstruction);
JumpHandler jumpHandler = createJumpHandler(node);
LocalsHandler savedLocals = localsHandler;
List<List<Constant>> matchExpressions = <List<Constant>>[];
List<HStatementInformation> statements = <HStatementInformation>[];
bool hasDefault = false;
Element getFallThroughErrorElement =
compiler.findHelper(const SourceString("getFallThroughError"));
Iterator<Node> caseIterator = node.cases.iterator();
while (caseIterator.hasNext()) {
SwitchCase switchCase = caseIterator.next();
List<Constant> caseConstants = <Constant>[];
HBasicBlock block = graph.addNewBlock();
for (Node labelOrCase in switchCase.labelsAndCases) {
if (labelOrCase is CaseMatch) {
Constant constant = constants[labelOrCase];
caseConstants.add(constant);
HConstant hConstant = graph.addConstant(constant);
switchInstruction.inputs.add(hConstant);
hConstant.usedBy.add(switchInstruction);
expressionBlock.addSuccessor(block);
}
}
matchExpressions.add(caseConstants);
if (switchCase.isDefaultCase) {
// An HSwitch has n inputs and n+1 successors, the last being the
// default case.
expressionBlock.addSuccessor(block);
hasDefault = true;
}
open(block);
localsHandler = new LocalsHandler.from(savedLocals);
visit(switchCase.statements);
if (!isAborted() && caseIterator.hasNext()) {
push(new HStatic(getFallThroughErrorElement));
HInstruction error = new HInvokeStatic(
Selector.INVOCATION_0, <HInstruction>[pop()]);
add(error);
close(new HThrow(error));
}
statements.add(
new HSubGraphBlockInformation(new SubGraph(block, lastOpenedBlock)));
}
// Add a join-block if necessary.
// We create [joinBlock] early, and then go through the cases that might
// want to jump to it. In each case, if we add [joinBlock] as a successor
// of another block, we also add an element to [caseLocals] that is used
// to create the phis in [joinBlock].
// If we never jump to the join block, [caseLocals] will stay empty, and
// the join block is never added to the graph.
HBasicBlock joinBlock = new HBasicBlock();
List<LocalsHandler> caseLocals = <LocalsHandler>[];
jumpHandler.forEachBreak((HBreak instruction, LocalsHandler locals) {
instruction.block.addSuccessor(joinBlock);
caseLocals.add(locals);
});
if (!isAborted()) {
current.close(new HGoto());
lastOpenedBlock.addSuccessor(joinBlock);
caseLocals.add(localsHandler);
}
if (!hasDefault) {
// The current flow is only aborted if the switch has a default that
// aborts (all previous cases must abort, and if there is no default,
// it's possible to miss all the cases).
expressionEnd.addSuccessor(joinBlock);
caseLocals.add(savedLocals);
}
assert(caseLocals.length == joinBlock.predecessors.length);
if (caseLocals.length != 0) {
graph.addBlock(joinBlock);
open(joinBlock);
if (caseLocals.length == 1) {
localsHandler = caseLocals[0];
} else {
localsHandler = savedLocals.mergeMultiple(caseLocals, joinBlock);
}
} else {
// The joinblock is not used.
joinBlock = null;
}
HSubExpressionBlockInformation expressionInfo =
new HSubExpressionBlockInformation(new SubExpression(expressionStart,
expressionEnd));
expressionStart.setBlockFlow(
new HSwitchBlockInformation(expressionInfo,
matchExpressions,
statements,
hasDefault,
jumpHandler.target,
jumpHandler.labels()),
joinBlock);
jumpHandler.close();
return true;
}
// Recursively build an if/else structure to match the cases.
void buildSwitchCases(Link<Node> cases, HInstruction expression,
[int encounteredCaseTypes = 0]) {
final int NO_TYPE = 0;
final int INT_TYPE = 1;
final int STRING_TYPE = 2;
final int CONFLICT_TYPE = 3;
int combine(int type1, int type2) => type1 | type2;
SwitchCase node = cases.head;
// Called for the statements on all but the last case block.
// Ensures that a user expecting a fallthrough gets an error.
void visitStatementsAndAbort() {
visit(node.statements);
if (!isAborted()) {
compiler.reportWarning(node, 'Missing break at end of switch case');
Element element =
compiler.findHelper(const SourceString("getFallThroughError"));
push(new HStatic(element));
HInstruction error = new HInvokeStatic(
Selector.INVOCATION_0, <HInstruction>[pop()]);
add(error);
close(new HThrow(error));
}
}
Link<Node> skipLabels(Link<Node> labelsAndCases) {
while (!labelsAndCases.isEmpty() && labelsAndCases.head is Label) {
labelsAndCases = labelsAndCases.tail;
}
return labelsAndCases;
}
Link<Node> labelsAndCases = skipLabels(node.labelsAndCases.nodes);
if (labelsAndCases.isEmpty()) {
// Default case with no expressions.
if (!node.isDefaultCase) {
compiler.internalError("Case with no expression and not default",
node: node);
}
visit(node.statements);
// This must be the final case (otherwise "default" would be invalid),
// so we don't need to check for fallthrough.
return;
}
// Recursively build the test conditions. Leaves the result on the
// expression stack.
void buildTests(Link<Node> remainingCases) {
// Build comparison for one case expression.
void left() {
Element equalsHelper = interceptors.getEqualsInterceptor();
HInstruction target = new HStatic(equalsHelper);
add(target);
CaseMatch match = remainingCases.head;
// TODO(lrn): Move the constant resolution to the resolver, so
// we can report an error before reaching the backend.
Constant constant =
compiler.constantHandler.tryCompileNodeWithDefinitions(
match.expression, elements);
if (constant !== null) {
if (constant.isInt()) {
// Report the first mixed-string/int type error only.
if (encounteredCaseTypes == STRING_TYPE) {
compiler.reportWarning(
match, MessageKind.INVALID_CASE_EXPRESSION_TYPE);
}
encounteredCaseTypes = combine(encounteredCaseTypes, INT_TYPE);
} else if (constant.isString()) {
if (encounteredCaseTypes == INT_TYPE) {
compiler.reportWarning(
match, MessageKind.INVALID_CASE_EXPRESSION_TYPE);
}
encounteredCaseTypes = combine(encounteredCaseTypes, STRING_TYPE);
} else {
compiler.reportWarning(match,
MessageKind.INVALID_CASE_EXPRESSION);
encounteredCaseTypes = CONFLICT_TYPE;
}
stack.add(graph.addConstant(constant));
} else {
// TODO(lrn): Remove this else branch, and make the constant
// evaluation mandatory when we are ready to break existing code using
// non constant-int-or-string expressions.
compiler.reportWarning(match,
'case expressions not compile-time constant int or string.');
visit(match.expression);
encounteredCaseTypes = CONFLICT_TYPE;
}
push(new HEquals(target, pop(), expression));
}
// If this is the last expression, just return it.
Link<Node> tail = skipLabels(remainingCases.tail);
if (tail.isEmpty()) {
left();
return;
}
void right() {
buildTests(tail);
}
handleLogicalAndOr(remainingCases.head, left, right, isAnd: false);
}
if (node.isDefaultCase) {
// Default case must be last.
assert(cases.tail.isEmpty());
// Perform the tests until one of them match, but then always execute the
// statements.
// TODO(lrn): Stop performing tests when all expressions are compile-time
// constant strings or integers.
handleIf(node, () { buildTests(labelsAndCases); }, (){}, null);
visit(node.statements);
} else {
if (cases.tail.isEmpty()) {
handleIf(node,
() { buildTests(labelsAndCases); },
() { visit(node.statements); },
null);
} else {
handleIf(node,
() { buildTests(labelsAndCases); },
() { visitStatementsAndAbort(); },
() { buildSwitchCases(cases.tail, expression,
encounteredCaseTypes); });
}
}
}
visitSwitchCase(SwitchCase node) {
compiler.internalError('SsaBuilder.visitSwitchCase');
}
visitCaseMatch(CaseMatch node) {
compiler.internalError('SsaBuilder.visitCaseMatch');
}
visitTryStatement(TryStatement node) {
work.allowSpeculativeOptimization = false;
// Save the current locals. The catch block and the finally block
// must not reuse the existing locals handler. None of the variables
// that have been defined in the body-block will be used, but for
// loops we will add (unnecessary) phis that will reference the body
// variables. This makes it look as if the variables were used
// in a non-dominated block.
LocalsHandler savedLocals = new LocalsHandler.from(localsHandler);
HBasicBlock enterBlock = openNewBlock();
HTry tryInstruction = new HTry();
List<HBasicBlock> blocks = <HBasicBlock>[];
blocks.add(close(tryInstruction));
HBasicBlock tryBody = graph.addNewBlock();
enterBlock.addSuccessor(tryBody);
open(tryBody);
visit(node.tryBlock);
if (!isAborted()) blocks.add(close(new HGoto()));
SubGraph bodyGraph = new SubGraph(tryBody, lastOpenedBlock);
SubGraph catchGraph = null;
HParameterValue exception = null;
if (!node.catchBlocks.isEmpty()) {
localsHandler = new LocalsHandler.from(savedLocals);
HBasicBlock block = graph.addNewBlock();
enterBlock.addSuccessor(block);
open(block);
// Note that the name of this element is irrelevant.
Element element = new Element(
const SourceString('exception'), ElementKind.PARAMETER, work.element);
exception = new HParameterValue(element);
add(exception);
HInstruction oldRethrowableException = rethrowableException;
rethrowableException = exception;
push(new HStatic(interceptors.getExceptionUnwrapper()));
List<HInstruction> inputs = <HInstruction>[pop(), exception];
HInvokeStatic unwrappedException =
new HInvokeStatic(Selector.INVOCATION_1, inputs);
add(unwrappedException);
tryInstruction.exception = exception;
Link<Node> link = node.catchBlocks.nodes;
void pushCondition(CatchBlock catchBlock) {
VariableDefinitions declaration = catchBlock.formals.nodes.head;
HInstruction condition = null;
if (declaration.type == null) {
condition = graph.addConstantBool(true);
stack.add(condition);
} else {
Type type = elements.getType(declaration.type);
if (type == null) {
compiler.cancel('Catch with unresolved type', node: catchBlock);
}
condition = new HIs(type, unwrappedException, nullOk: true);
push(condition);
}
}
void visitThen() {
CatchBlock catchBlock = link.head;
link = link.tail;
localsHandler.updateLocal(elements[catchBlock.exception],
unwrappedException);
Node trace = catchBlock.trace;
if (trace != null) {
push(new HStatic(interceptors.getTraceFromException()));
HInstruction traceInstruction = new HInvokeStatic(
Selector.INVOCATION_1, <HInstruction>[pop(), exception]);
add(traceInstruction);
localsHandler.updateLocal(elements[trace], traceInstruction);
}
visit(catchBlock);
}
void visitElse() {
if (link.isEmpty()) {
close(new HThrow(exception, isRethrow: true));
} else {
CatchBlock newBlock = link.head;
handleIf(node,
() { pushCondition(newBlock); },
visitThen, visitElse);
}
}
CatchBlock firstBlock = link.head;
handleIf(node, () { pushCondition(firstBlock); }, visitThen, visitElse);
if (!isAborted()) blocks.add(close(new HGoto()));
rethrowableException = oldRethrowableException;
tryInstruction.catchBlock = block;
catchGraph = new SubGraph(block, lastOpenedBlock);
}
SubGraph finallyGraph = null;
if (node.finallyBlock != null) {
localsHandler = new LocalsHandler.from(savedLocals);
HBasicBlock finallyBlock = graph.addNewBlock();
enterBlock.addSuccessor(finallyBlock);
open(finallyBlock);
visit(node.finallyBlock);
if (!isAborted()) blocks.add(close(new HGoto()));
tryInstruction.finallyBlock = finallyBlock;
finallyGraph = new SubGraph(finallyBlock, lastOpenedBlock);
}
HBasicBlock exitBlock = graph.addNewBlock();
for (HBasicBlock block in blocks) {
block.addSuccessor(exitBlock);
}
// Use the locals handler not altered by the catch and finally
// blocks.
localsHandler = savedLocals;
open(exitBlock);
enterBlock.setBlockFlow(
new HTryBlockInformation(
wrapStatementGraph(bodyGraph),
exception,
wrapStatementGraph(catchGraph),
wrapStatementGraph(finallyGraph)),
exitBlock);
}
visitScriptTag(ScriptTag node) {
compiler.unimplemented('SsaBuilder.visitScriptTag', node: node);
}
visitCatchBlock(CatchBlock node) {
visit(node.block);
}
visitTypedef(Typedef node) {
compiler.unimplemented('SsaBuilder.visitTypedef', node: node);
}
visitTypeVariable(TypeVariable node) {
compiler.internalError('SsaBuilder.visitTypeVariable');
}
/** HACK HACK HACK */
void hackAroundPossiblyAbortingBody(Node statement, void body()) {
visitCondition() {
stack.add(graph.addConstantBool(true));
}
buildBody() {
// TODO(lrn): Make sure to take continue into account.
body();
}
handleIf(statement, visitCondition, buildBody, null);
}
}
/**
* Visitor that handles generation of string literals (LiteralString,
* StringInterpolation), and otherwise delegates to the given visitor for
* non-literal subexpressions.
* TODO(lrn): Consider whether to handle compile time constant int/boolean
* expressions as well.
*/
class StringBuilderVisitor extends AbstractVisitor {
final SsaBuilder builder;
final Node diagnosticNode;
/**
* The string value generated so far.
*/
HInstruction result = null;
StringBuilderVisitor(this.builder, this.diagnosticNode);
void visit(Node node) {
node.accept(this);
}
visitNode(Node node) {
builder.compiler.internalError('unexpected node', node: node);
}
void visitExpression(Node node) {
node.accept(builder);
HInstruction expression = builder.pop();
result = (result === null) ? expression : concat(result, expression);
}
void visitStringInterpolation(StringInterpolation node) {
node.visitChildren(this);
}
void visitStringInterpolationPart(StringInterpolationPart node) {
visit(node.expression);
visit(node.string);
}
void visitStringJuxtaposition(StringJuxtaposition node) {
node.visitChildren(this);
}
void visitNodeList(NodeList node) {
node.visitChildren(this);
}
HInstruction concat(HInstruction left, HInstruction right) {
HInstruction instruction = new HStringConcat(left, right, diagnosticNode);
builder.add(instruction);
return instruction;
}
}
class SsaBranch {
final SsaBranchBuilder branchBuilder;
final HBasicBlock block;
LocalsHandler startLocals;
LocalsHandler exitLocals;
SubGraph graph;
SsaBranch(this.branchBuilder) : block = new HBasicBlock();
}
class SsaBranchBuilder {
final SsaBuilder builder;
final Node diagnosticNode;
SsaBranchBuilder(this.builder, [this.diagnosticNode]);
Compiler get compiler() => builder.compiler;
void checkNotAborted() {
if (builder.isAborted()) {
compiler.unimplemented("aborted control flow", node: diagnosticNode);
}
}
void buildCondition(void visitCondition(),
SsaBranch conditionBranch,
SsaBranch thenBranch,
SsaBranch elseBranch) {
startBranch(conditionBranch);
visitCondition();
checkNotAborted();
assert(builder.current === builder.lastOpenedBlock);
HInstruction conditionValue = builder.popBoolified();
HIf branch = new HIf(conditionValue);
HBasicBlock conditionExitBlock = builder.current;
builder.close(branch);
conditionBranch.exitLocals = builder.localsHandler;
conditionExitBlock.addSuccessor(thenBranch.block);
conditionExitBlock.addSuccessor(elseBranch.block);
bool conditionBranchLocalsCanBeReused =
mergeLocals(conditionBranch, thenBranch, mayReuseFromLocals: true);
mergeLocals(conditionBranch, elseBranch,
mayReuseFromLocals: conditionBranchLocalsCanBeReused);
conditionBranch.graph =
new SubExpression(conditionBranch.block, conditionExitBlock);
}
/**
* Returns true if the locals of the [fromBranch] may be reused. A [:true:]
* return value implies that [mayReuseFromLocals] was set to [:true:].
*/
bool mergeLocals(SsaBranch fromBranch, SsaBranch toBranch,
[bool mayReuseFromLocals]) {
LocalsHandler fromLocals = fromBranch.exitLocals;
if (toBranch.startLocals == null) {
if (mayReuseFromLocals) {
toBranch.startLocals = fromLocals;
return false;
} else {
toBranch.startLocals = new LocalsHandler.from(fromLocals);
return true;
}
} else {
toBranch.startLocals.mergeWith(fromLocals, toBranch.block);
return true;
}
}
void startBranch(SsaBranch branch) {
builder.graph.addBlock(branch.block);
builder.localsHandler = branch.startLocals;
builder.open(branch.block);
}
HInstruction buildBranch(SsaBranch branch,
void visitBranch(),
SsaBranch joinBranch,
bool isExpression) {
startBranch(branch);
visitBranch();
branch.graph = new SubGraph(branch.block, builder.lastOpenedBlock);
branch.exitLocals = builder.localsHandler;
if (!builder.isAborted()) {
builder.goto(builder.current, joinBranch.block);
mergeLocals(branch, joinBranch, mayReuseFromLocals: true);
}
if (isExpression) {
checkNotAborted();
return builder.pop();
}
return null;
}
handleIf(void visitCondition(), void visitThen(), void visitElse()) {
if (visitElse == null) {
// Make sure to have an else part to avoid a critical edge. A
// critical edge is an edge that connects a block with multiple
// successors to a block with multiple predecessors. We avoid
// such edges because they prevent inserting copies during code
// generation of phi instructions.
visitElse = () {};
}
_handleDiamondBranch(visitCondition, visitThen, visitElse, false);
}
handleConditional(void visitCondition(), void visitThen(), void visitElse()) {
assert(visitElse != null);
_handleDiamondBranch(visitCondition, visitThen, visitElse, true);
}
void _handleDiamondBranch(void visitCondition(),
void visitThen(),
void visitElse(),
bool isExpression) {
SsaBranch conditionBranch = new SsaBranch(this);
SsaBranch thenBranch = new SsaBranch(this);
SsaBranch elseBranch = new SsaBranch(this);
SsaBranch joinBranch = new SsaBranch(this);
conditionBranch.startLocals = builder.localsHandler;
builder.goto(builder.current, conditionBranch.block);
buildCondition(visitCondition, conditionBranch, thenBranch, elseBranch);
HInstruction thenValue =
buildBranch(thenBranch, visitThen, joinBranch, isExpression);
HInstruction elseValue =
buildBranch(elseBranch, visitElse, joinBranch, isExpression);
if (isExpression) {
assert(thenValue != null && elseValue != null);
HPhi phi =
new HPhi.manyInputs(null, <HInstruction>[thenValue, elseValue]);
joinBranch.block.addPhi(phi);
builder.stack.add(phi);
}
HBasicBlock thenBlock = thenBranch.block;
HBasicBlock elseBlock = elseBranch.block;
HBasicBlock joinBlock;
// If at least one branch did not abort, open the joinBranch.
if (!joinBranch.block.predecessors.isEmpty()) {
startBranch(joinBranch);
joinBlock = joinBranch.block;
}
HIfBlockInformation info =
new HIfBlockInformation(
new HSubExpressionBlockInformation(conditionBranch.graph),
new HSubGraphBlockInformation(thenBranch.graph),
new HSubGraphBlockInformation(elseBranch.graph));
HBasicBlock conditionStartBlock = conditionBranch.block;
conditionStartBlock.setBlockFlow(info, joinBlock);
SubGraph conditionGraph = conditionBranch.graph;
HIf branch = conditionGraph.end.last;
assert(branch is HIf);
branch.blockInformation = conditionStartBlock.blockFlow;
}
}