Files
sdk/lib/compiler/implementation/compiler.dart
T
2012-08-21 17:39:07 +00:00

909 lines
31 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.
/**
* If true, print a warning for each method that was resolved, but not
* compiled.
*/
final bool REPORT_EXCESS_RESOLUTION = false;
/**
* If true, trace information on pass2 optimizations.
*/
final bool REPORT_PASS2_OPTIMIZATIONS = false;
/**
* Contains backend-specific data that is used throughout the compilation of
* one work item.
*/
class ItemCompilationContext {
}
class WorkItem {
final ItemCompilationContext compilationContext;
final Element element;
TreeElements resolutionTree;
bool allowSpeculativeOptimization = true;
List<HTypeGuard> guards = const <HTypeGuard>[];
WorkItem(this.element, this.resolutionTree, this.compilationContext);
bool isAnalyzed() => resolutionTree !== null;
void run(Compiler compiler, Enqueuer world) {
CodeBuffer codeBuffer = world.universe.generatedCode[element];
if (codeBuffer !== null) return;
resolutionTree = compiler.analyze(this, world);
compiler.codegen(this, world);
}
}
class Backend {
final Compiler compiler;
Backend(this.compiler);
void enqueueAllTopLevelFunctions(LibraryElement lib, Enqueuer world) {
lib.forEachExport((Element e) {
if (e.isFunction()) world.addToWorkList(e);
});
}
abstract void enqueueHelpers(Enqueuer world);
abstract void codegen(WorkItem work);
abstract void processNativeClasses(Enqueuer world,
Collection<LibraryElement> libraries);
abstract void assembleProgram();
abstract List<CompilerTask> get tasks();
ItemCompilationContext createItemCompilationContext() {
return new ItemCompilationContext();
}
}
class Compiler implements DiagnosticListener {
final Map<String, LibraryElement> libraries;
int nextFreeClassId = 0;
World world;
String assembledCode;
Namer namer;
Types types;
final bool enableTypeAssertions;
final bool enableUserAssertions;
final Tracer tracer;
CompilerTask measuredTask;
Element _currentElement;
LibraryElement coreLibrary;
LibraryElement coreImplLibrary;
LibraryElement isolateLibrary;
LibraryElement jsHelperLibrary;
LibraryElement interceptorsLibrary;
LibraryElement mainApp;
ClassElement objectClass;
ClassElement closureClass;
ClassElement dynamicClass;
ClassElement boolClass;
ClassElement numClass;
ClassElement intClass;
ClassElement doubleClass;
ClassElement stringClass;
ClassElement functionClass;
ClassElement nullClass;
ClassElement listClass;
Element assertMethod;
/**
* Interface used to determine if an object has the JavaScript
* indexing behavior. The interface is only visible to specific
* libraries.
*/
ClassElement jsIndexingBehaviorInterface;
Element get currentElement() => _currentElement;
withCurrentElement(Element element, f()) {
Element old = currentElement;
_currentElement = element;
try {
return f();
} catch (CompilerCancelledException ex) {
throw;
} catch (StackOverflowException ex) {
// We cannot report anything useful in this case, because we
// do not have enough stack space.
throw;
} catch (var ex) {
try {
unhandledExceptionOnElement(element);
} catch (var doubleFault) {
// Ignoring exceptions in exception handling.
}
throw;
} finally {
_currentElement = old;
}
}
List<CompilerTask> tasks;
ScannerTask scanner;
DietParserTask dietParser;
ParserTask parser;
PatchParserTask patchParser;
TreeValidatorTask validator;
ResolverTask resolver;
closureMapping.ClosureTask closureToClassMapper;
TypeCheckerTask checker;
ti.TypesTask typesTask;
Backend backend;
ConstantHandler constantHandler;
EnqueueTask enqueuer;
static final SourceString MAIN = const SourceString('main');
static final SourceString CALL_OPERATOR_NAME = const SourceString('call');
static final SourceString NO_SUCH_METHOD = const SourceString('noSuchMethod');
static final SourceString NO_SUCH_METHOD_EXCEPTION =
const SourceString('NoSuchMethodException');
static final SourceString START_ROOT_ISOLATE =
const SourceString('startRootIsolate');
bool enabledNoSuchMethod = false;
Stopwatch progress;
static final int PHASE_SCANNING = 0;
static final int PHASE_RESOLVING = 1;
static final int PHASE_COMPILING = 2;
static final int PHASE_RECOMPILING = 3;
int phase;
bool compilationFailed = false;
bool hasCrashed = false;
Compiler([this.tracer = const Tracer(),
this.enableTypeAssertions = false,
this.enableUserAssertions = false,
bool emitJavascript = true,
validateUnparse = false,
generateSourceMap = true])
: libraries = new Map<String, LibraryElement>(),
world = new World(),
progress = new Stopwatch.start() {
namer = new Namer(this);
constantHandler = new ConstantHandler(this);
scanner = new ScannerTask(this);
dietParser = new DietParserTask(this);
parser = new ParserTask(this);
patchParser = new PatchParserTask(this);
validator = new TreeValidatorTask(this);
resolver = new ResolverTask(this);
closureToClassMapper = new closureMapping.ClosureTask(this);
checker = new TypeCheckerTask(this);
typesTask = new ti.TypesTask(this);
backend = emitJavascript ?
new js_backend.JavaScriptBackend(this, generateSourceMap) :
new dart_backend.DartBackend(this, validateUnparse);
enqueuer = new EnqueueTask(this);
tasks = [scanner, dietParser, parser, resolver, closureToClassMapper,
checker, typesTask, constantHandler, enqueuer];
tasks.addAll(backend.tasks);
}
Universe get resolverWorld() => enqueuer.resolution.universe;
Universe get codegenWorld() => enqueuer.codegen.universe;
int getNextFreeClassId() => nextFreeClassId++;
void ensure(bool condition) {
if (!condition) cancel('failed assertion in leg');
}
void unimplemented(String methodName,
[Node node, Token token, HInstruction instruction,
Element element]) {
internalError("$methodName not implemented",
node, token, instruction, element);
}
void internalError(String message,
[Node node, Token token, HInstruction instruction,
Element element]) {
cancel('Internal error: $message', node, token, instruction, element);
}
void internalErrorOnElement(Element element, String message) {
internalError(message, element: element);
}
void unhandledExceptionOnElement(Element element) {
if (hasCrashed) return;
hasCrashed = true;
reportDiagnostic(spanFromElement(element),
MessageKind.COMPILER_CRASHED.error().toString(),
api.Diagnostic.CRASH);
// TODO(ahe): Obtain the build ID.
var buildId = 'build number could not be determined';
print(MessageKind.PLEASE_REPORT_THE_CRASH.message([buildId]));
}
void cancel([String reason, Node node, Token token,
HInstruction instruction, Element element]) {
assembledCode = null; // Compilation failed. Make sure that we
// don't return a bogus result.
SourceSpan span = null;
if (node !== null) {
span = spanFromNode(node);
} else if (token !== null) {
span = spanFromTokens(token, token);
} else if (instruction !== null) {
span = spanFromElement(currentElement);
} else if (element !== null) {
span = spanFromElement(element);
} else {
throw 'No error location for error: $reason';
}
reportDiagnostic(span, reason, api.Diagnostic.ERROR);
throw new CompilerCancelledException(reason);
}
void reportFatalError(String reason, Element element,
[Node node, Token token, HInstruction instruction]) {
withCurrentElement(element, () {
cancel(reason, node, token, instruction, element);
});
}
void log(message) {
reportDiagnostic(null, message, api.Diagnostic.VERBOSE_INFO);
}
bool run(Uri uri) {
try {
runCompiler(uri);
} catch (CompilerCancelledException exception) {
log(exception.toString());
log('compilation failed');
return false;
}
tracer.close();
log('compilation succeeded');
return true;
}
void enableNoSuchMethod(Element element) {
// TODO(ahe): Move this method to Enqueuer.
if (enabledNoSuchMethod) return;
if (element.getEnclosingClass() === objectClass) {
enqueuer.resolution.registerDynamicInvocationOf(element);
return;
}
enabledNoSuchMethod = true;
Selector selector = new Selector.noSuchMethod();
enqueuer.resolution.registerInvocation(NO_SUCH_METHOD, selector);
enqueuer.codegen.registerInvocation(NO_SUCH_METHOD, selector);
}
void enableIsolateSupport(LibraryElement element) {
// TODO(ahe): Move this method to Enqueuer.
isolateLibrary = element;
enqueuer.resolution.addToWorkList(element.find(START_ROOT_ISOLATE));
enqueuer.resolution.addToWorkList(
element.find(const SourceString('_currentIsolate')));
enqueuer.resolution.addToWorkList(
element.find(const SourceString('_callInIsolate')));
enqueuer.codegen.addToWorkList(element.find(START_ROOT_ISOLATE));
}
bool hasIsolateSupport() => isolateLibrary !== null;
void onLibraryLoaded(LibraryElement library, Uri uri) {
if (uri.toString() == 'dart:isolate') {
enableIsolateSupport(library);
}
if (dynamicClass !== null) {
// When loading the built-in libraries, dynamicClass is null. We
// take advantage of this as core and coreimpl import js_helper
// and see Dynamic this way.
withCurrentElement(dynamicClass, () {
library.addToScope(dynamicClass, this);
});
}
}
abstract LibraryElement scanBuiltinLibrary(String filename);
void initializeSpecialClasses() {
bool coreLibValid = true;
ClassElement lookupSpecialClass(SourceString name) {
ClassElement result = coreLibrary.find(name);
if (result === null) {
log('core library class $name missing');
coreLibValid = false;
}
return result;
}
objectClass = lookupSpecialClass(const SourceString('Object'));
boolClass = lookupSpecialClass(const SourceString('bool'));
numClass = lookupSpecialClass(const SourceString('num'));
intClass = lookupSpecialClass(const SourceString('int'));
doubleClass = lookupSpecialClass(const SourceString('double'));
stringClass = lookupSpecialClass(const SourceString('String'));
functionClass = lookupSpecialClass(const SourceString('Function'));
listClass = lookupSpecialClass(const SourceString('List'));
closureClass = lookupSpecialClass(const SourceString('Closure'));
dynamicClass = lookupSpecialClass(const SourceString('Dynamic'));
nullClass = lookupSpecialClass(const SourceString('Null'));
types = new Types(this, dynamicClass);
if (!coreLibValid) {
cancel('core library does not contain required classes');
}
jsIndexingBehaviorInterface =
findHelper(const SourceString('JavaScriptIndexingBehavior'));
}
void scanBuiltinLibraries() {
coreImplLibrary = scanBuiltinLibrary('coreimpl');
jsHelperLibrary = scanBuiltinLibrary('_js_helper');
interceptorsLibrary = scanBuiltinLibrary('_interceptors');
addForeignFunctions(jsHelperLibrary);
addForeignFunctions(interceptorsLibrary);
libraries['dart:core'] = coreLibrary;
libraries['dart:coreimpl'] = coreImplLibrary;
assertMethod = coreLibrary.find(const SourceString('assert'));
initializeSpecialClasses();
//patchDartLibrary(coreLibrary, 'core');
//patchDartLibrary(coreImplLibrary, 'coreimpl');
}
void importCoreLibrary(LibraryElement library) {
Uri coreUri = new Uri.fromComponents(scheme: 'dart', path: 'core');
if (coreLibrary === null) {
coreLibrary = scanner.loadLibrary(coreUri, null, coreUri);
}
scanner.importLibrary(library,
coreLibrary,
null,
library.entryCompilationUnit);
}
void patchDartLibrary(LibraryElement library, String dartLibraryPath) {
if (library.isPatched) return;
Uri patchUri = resolvePatchUri(dartLibraryPath);
if (patchUri !== null) {
patchParser.patchLibrary(patchUri, library);
}
}
void applyContainerPatch(ScopeContainerElement original,
Link<Element> patches) {
while (!patches.isEmpty()) {
Element patchElement = patches.head;
Element originalElement = original.localLookup(patchElement.name);
if (patchElement.isAccessor()) {
// TODO(lrn): When we change to always add accessors to members, and
// not add abstract fields, the logic here should be reversed.
// For now, access getters through the abstract field and skip
// any accessors.
} else if (patchElement.kind === ElementKind.ABSTRACT_FIELD) {
// Getters and setters are kept inside a synthetic field.
if (originalElement !== null &&
originalElement.kind !== ElementKind.ABSTRACT_FIELD) {
internalError("Cannot patch non-getter/setter with getter/setter",
element: originalElement);
}
AbstractFieldElement patchField = patchElement;
AbstractFieldElement originalField = originalElement;
if (patchField.getter !== null) {
if (originalField === null || originalField.getter === null) {
original.addGetterOrSetter(clonePatch(patchField.getter, original),
originalField,
this);
if (originalField === null && patchField.setter !== null) {
// It exists now, so find it for the setter patching.
originalField = original.localLookup(patchElement.name);
}
} else {
patchMember(originalField.getter, patchField.getter);
}
}
if (patchField.setter !== null) {
if (originalField === null || originalField.setter === null) {
original.addGetterOrSetter(clonePatch(patchField.setter, original),
originalField,
this);
} else {
patchMember(originalField.setter, patchField.setter);
}
}
} else if (originalElement === null) {
if (isPatchElement(patchElement)) {
internalError("Cannot patch non-existing member '"
"${patchElement.name.slowToString()}'.");
}
original.addMember(clonePatch(patchElement, original), this);
} else {
patchMember(originalElement, patchElement);
}
patches = patches.tail;
}
}
bool isPatchElement(Element element) {
// TODO(lrn): More checks needed if we introduce metadata for real.
// In that case, it must have the identifier "native" as metadata.
return !element.metadata.isEmpty();
}
Element clonePatch(Element patchElement, Element enclosing) {
// The original library does not have an element with the same name
// as the patch library element.
// In this case, the patch library element must not be marked as "patch",
// and its name must make it private.
if (!patchElement.name.isPrivate()) {
internalError("Cannot add non-private member '"
"${patchElement.name.slowToString()}' from patch.");
}
Element override =
new CompilationUnitOverrideElement(patchElement.getCompilationUnit(),
enclosing);
return patchElement.cloneTo(override, this);
}
void patchMember(Element originalElement, Element patchElement) {
// The original library has an element with the same name as the patch
// library element.
// In this case, the patch library element must be a function marked as
// "patch" and it must have the same signature as the function it patches.
if (!isPatchElement(patchElement)) {
internalError("Cannot overwrite existing '"
"${originalElement.name.slowToString()}' with non-patch.");
}
if (originalElement is! FunctionElement) {
// TODO(lrn): Handle class declarations too.
internalError("Can only patch functions", element: originalElement);
}
FunctionElement original = originalElement;
if (!original.modifiers.isExternal()) {
internalError("Can only patch external functions.", element: original);
}
if (patchElement is! FunctionElement ||
!patchSignatureMatches(original, patchElement)) {
internalError("Can only patch functions with matching signatures",
element: original);
}
applyFunctionPatch(original, patchElement);
}
bool patchSignatureMatches(FunctionElement original, FunctionElement patch) {
// TODO(lrn): Check that patches actually match the signature of
// the function it's patching.
return true;
}
void applyFunctionPatch(FunctionElement element,
FunctionElement patchElement) {
if (element.isPatched) {
internalError("Trying to patch a function more than once.",
element: element);
}
if (element.cachedNode !== null) {
internalError("Trying to patch an already compiled function.",
element: element);
}
// Don't just assign the patch field. This also updates the cachedNode.
element.setPatch(patchElement);
}
/**
* Get an [Uri] pointing to a patch for the dart: library with
* the given path. Returns null if there is no patch.
*/
abstract Uri resolvePatchUri(String dartLibraryPath);
/** Define the JS helper functions in the given library. */
void addForeignFunctions(LibraryElement library) {
library.addToScope(new ForeignElement(
const SourceString('JS'), library), this);
library.addToScope(new ForeignElement(
const SourceString('UNINTERCEPTED'), library), this);
library.addToScope(new ForeignElement(
const SourceString('JS_HAS_EQUALS'), library), this);
library.addToScope(new ForeignElement(
const SourceString('JS_CURRENT_ISOLATE'), library), this);
library.addToScope(new ForeignElement(
const SourceString('JS_CALL_IN_ISOLATE'), library), this);
library.addToScope(new ForeignElement(
const SourceString('DART_CLOSURE_TO_JS'), library), this);
}
void runCompiler(Uri uri) {
scanBuiltinLibraries();
mainApp = scanner.loadLibrary(uri, null, uri);
final Element main = mainApp.find(MAIN);
if (main === null) {
reportFatalError('Could not find $MAIN', mainApp);
} else {
if (!main.isFunction()) reportFatalError('main is not a function', main);
FunctionElement mainMethod = main;
FunctionSignature parameters = mainMethod.computeSignature(this);
parameters.forEachParameter((Element parameter) {
reportFatalError('main cannot have parameters', parameter);
});
}
log('Resolving...');
phase = PHASE_RESOLVING;
backend.enqueueHelpers(enqueuer.resolution);
processQueue(enqueuer.resolution, main);
log('Resolved ${enqueuer.resolution.resolvedElements.length} elements.');
if (compilationFailed) return;
log('Inferring types...');
typesTask.onResolutionComplete();
// TODO(ahe): Remove this line. Eventually, enqueuer.resolution
// should know this.
world.populate(this);
log('Compiling...');
phase = PHASE_COMPILING;
processQueue(enqueuer.codegen, main);
log("Recompiling ${enqueuer.codegen.recompilationCandidates.length} "
"methods...");
phase = PHASE_RECOMPILING;
processRecompilationQueue(enqueuer.codegen);
log('Compiled ${codegenWorld.generatedCode.length} methods.');
if (compilationFailed) return;
backend.assembleProgram();
checkQueues();
}
void processQueue(Enqueuer world, Element main) {
backend.processNativeClasses(world, libraries.getValues());
world.addToWorkList(main);
progress.reset();
world.forEach((WorkItem work) {
withCurrentElement(work.element, () => work.run(this, world));
});
world.queueIsClosed = true;
if (compilationFailed) return;
assert(world.checkNoEnqueuedInvokedInstanceMethods());
}
void processRecompilationQueue(Enqueuer world) {
assert(phase == PHASE_RECOMPILING);
while (!world.recompilationCandidates.isEmpty()) {
WorkItem work = world.recompilationCandidates.next();
CodeBuffer oldCode = world.universe.generatedCode[work.element];
world.universe.generatedCode.remove(work.element);
world.universe.generatedBailoutCode.remove(work.element);
withCurrentElement(work.element, () => work.run(this, world));
CodeBuffer newCode = world.universe.generatedCode[work.element];
if (REPORT_PASS2_OPTIMIZATIONS && newCode != oldCode) {
log("Pass 2 optimization:");
log("Before:\n$oldCode");
log("After:\n$newCode");
}
}
}
/**
* Perform various checks of the queues. This includes checking that
* the queues are empty (nothing was added after we stopped
* processing the queues). Also compute the number of methods that
* were resolved, but not compiled (aka excess resolution).
*/
checkQueues() {
for (Enqueuer world in [enqueuer.resolution, enqueuer.codegen]) {
world.forEach((WorkItem work) {
internalErrorOnElement(work.element, "Work list is not empty.");
});
}
var resolved = new Set.from(enqueuer.resolution.resolvedElements.getKeys());
for (Element e in codegenWorld.generatedCode.getKeys()) {
resolved.remove(e);
}
for (Element e in new Set.from(resolved)) {
if (e.isClass() ||
e.isField() ||
e.isTypeVariable() ||
e.isTypedef() ||
e.kind === ElementKind.ABSTRACT_FIELD) {
resolved.remove(e);
}
if (e.kind === ElementKind.GENERATIVE_CONSTRUCTOR) {
ClassElement enclosingClass = e.getEnclosingClass();
if (enclosingClass.isInterface()) {
resolved.remove(e);
}
resolved.remove(e);
}
if (e.getLibrary() === jsHelperLibrary) {
resolved.remove(e);
}
if (e.getLibrary() === interceptorsLibrary) {
resolved.remove(e);
}
}
log('Excess resolution work: ${resolved.length}.');
if (!REPORT_EXCESS_RESOLUTION) return;
for (Element e in resolved) {
SourceSpan span = spanFromElement(e);
reportDiagnostic(span, 'Warning: $e resolved but not compiled.',
api.Diagnostic.WARNING);
}
}
TreeElements analyzeElement(Element element) {
TreeElements elements = enqueuer.resolution.getCachedElements(element);
if (elements !== null) return elements;
final int allowed = ElementCategory.VARIABLE | ElementCategory.FUNCTION
| ElementCategory.FACTORY;
ElementKind kind = element.kind;
if (!element.isAccessor() &&
((kind === ElementKind.ABSTRACT_FIELD) ||
(kind.category & allowed) == 0)) {
return null;
}
assert(parser !== null);
Node tree = parser.parse(element);
validator.validate(tree);
elements = resolver.resolve(element);
checker.check(tree, elements);
typesTask.analyze(tree, elements);
return elements;
}
TreeElements analyze(WorkItem work, Enqueuer world) {
if (work.isAnalyzed()) {
// TODO(ahe): Clean this up and find a better way for adding all resolved
// elements.
enqueuer.resolution.resolvedElements[work.element] = work.resolutionTree;
return work.resolutionTree;
}
if (progress.elapsedInMs() > 500) {
// TODO(ahe): Add structured diagnostics to the compiler API and
// use it to separate this from the --verbose option.
if (phase == PHASE_RESOLVING) {
log('Resolved ${enqueuer.resolution.resolvedElements.length} '
'elements.');
progress.reset();
}
}
Element element = work.element;
TreeElements result = world.getCachedElements(element);
if (result !== null) return result;
if (world !== enqueuer.resolution) {
internalErrorOnElement(element,
'Internal error: unresolved element: $element.');
}
result = analyzeElement(element);
enqueuer.resolution.resolvedElements[element] = result;
return result;
}
void codegen(WorkItem work, Enqueuer world) {
if (world !== enqueuer.codegen) return null;
if (progress.elapsedInMs() > 500) {
// TODO(ahe): Add structured diagnostics to the compiler API and
// use it to separate this from the --verbose option.
if (phase == PHASE_COMPILING) {
log('Compiled ${codegenWorld.generatedCode.length} methods.');
} else {
log('Recompiled ${world.recompilationCandidates.processed} methods.');
}
progress.reset();
}
if (work.element.kind.category == ElementCategory.VARIABLE) {
constantHandler.compileWorkItem(work);
} else {
backend.codegen(work);
}
}
void registerInstantiatedClass(ClassElement cls) {
enqueuer.resolution.registerInstantiatedClass(cls);
enqueuer.codegen.registerInstantiatedClass(cls);
}
Type resolveTypeAnnotation(Element element, TypeAnnotation annotation) {
return resolver.resolveTypeAnnotation(element, annotation);
}
FunctionSignature resolveSignature(FunctionElement element) {
return withCurrentElement(element,
() => resolver.resolveSignature(element));
}
FunctionSignature resolveFunctionExpression(Element element,
FunctionExpression node) {
return withCurrentElement(element,
() => resolver.resolveFunctionExpression(element, node));
}
void resolveTypedef(TypedefElement element) {
withCurrentElement(element,
() => resolver.resolveTypedef(element));
}
FunctionType computeFunctionType(Element element,
FunctionSignature signature) {
return withCurrentElement(element,
() => resolver.computeFunctionType(element, signature));
}
Constant compileVariable(VariableElement element) {
return withCurrentElement(element, () {
return constantHandler.compileVariable(element);
});
}
reportWarning(Node node, var message) {
if (message is TypeWarning) {
// TODO(ahe): Don't supress these warning when the type checker
// is more complete.
if (message.message.kind === MessageKind.NOT_ASSIGNABLE) return;
if (message.message.kind === MessageKind.MISSING_RETURN) return;
if (message.message.kind === MessageKind.MAYBE_MISSING_RETURN) return;
if (message.message.kind === MessageKind.ADDITIONAL_ARGUMENT) return;
if (message.message.kind === MessageKind.METHOD_NOT_FOUND) return;
}
SourceSpan span = spanFromNode(node);
reportDiagnostic(span, 'Warning: $message', api.Diagnostic.WARNING);
}
reportError(Node node, var message) {
SourceSpan span = spanFromNode(node);
reportDiagnostic(span, 'Error: $message', api.Diagnostic.ERROR);
throw new CompilerCancelledException(message.toString());
}
void reportMessage(SourceSpan span,
Diagnostic message,
api.Diagnostic kind) {
// TODO(ahe): The names Diagnostic and api.Diagnostic are in
// conflict. Fix it.
reportDiagnostic(span, "$message", kind);
}
abstract void reportDiagnostic(SourceSpan span, String message,
api.Diagnostic kind);
SourceSpan spanFromTokens(Token begin, Token end, [Uri uri]) {
if (begin === null || end === null) {
// TODO(ahe): We can almost always do better. Often it is only
// end that is null. Otherwise, we probably know the current
// URI.
throw 'Cannot find tokens to produce error message.';
}
if (uri === null && currentElement !== null) {
uri = currentElement.getCompilationUnit().script.uri;
}
return SourceSpan.withCharacterOffsets(begin, end,
(beginOffset, endOffset) => new SourceSpan(uri, beginOffset, endOffset));
}
SourceSpan spanFromNode(Node node, [Uri uri]) {
return spanFromTokens(node.getBeginToken(), node.getEndToken(), uri);
}
SourceSpan spanFromElement(Element element) {
if (element.position() === null) {
// Sometimes, the backend fakes up elements that have no
// position. So we use the enclosing element instead. It is
// not a good error location, but cancel really is "internal
// error" or "not implemented yet", so the vicinity is good
// enough for now.
element = element.enclosingElement;
// TODO(ahe): I plan to overhaul this infrastructure anyways.
}
if (element === null) {
element = currentElement;
}
Token position = element.position();
Uri uri = element.getCompilationUnit().script.uri;
return (position === null)
? new SourceSpan(uri, 0, 0)
: spanFromTokens(position, position, uri);
}
Script readScript(Uri uri, [ScriptTag node]) {
unimplemented('Compiler.readScript');
}
String get legDirectory() {
unimplemented('Compiler.legDirectory');
}
Element findHelper(SourceString name)
=> jsHelperLibrary.findLocal(name);
Element findInterceptor(SourceString name)
=> interceptorsLibrary.findLocal(name);
bool get isMockCompilation() => false;
}
class CompilerTask {
final Compiler compiler;
final Stopwatch watch;
CompilerTask(this.compiler) : watch = new Stopwatch();
String get name() => 'Unknown task';
int get timing() => watch.elapsedInMs();
measure(Function action) {
// TODO(kasperl): Do we have to worry about exceptions here?
CompilerTask previous = compiler.measuredTask;
compiler.measuredTask = this;
if (previous !== null) previous.watch.stop();
watch.start();
var result = action();
watch.stop();
if (previous !== null) previous.watch.start();
compiler.measuredTask = previous;
return result;
}
}
class CompilerCancelledException implements Exception {
final String reason;
CompilerCancelledException(this.reason);
String toString() {
String banner = 'compiler cancelled';
return (reason !== null) ? '$banner: $reason' : '$banner';
}
}
class Tracer {
final bool enabled = false;
const Tracer();
void traceCompilation(String methodName, ItemCompilationContext context) {
}
void traceGraph(String name, var graph) {
}
void close() {
}
}
class SourceSpan {
final Uri uri;
final int begin;
final int end;
const SourceSpan(this.uri, this.begin, this.end);
static withCharacterOffsets(Token begin, Token end,
f(int beginOffset, int endOffset)) {
final beginOffset = begin.charOffset;
final endOffset = end.charOffset + end.slowCharCount;
// [begin] and [end] might be the same for the same empty token. This
// happens for instance when scanning '$$'.
assert(endOffset >= beginOffset);
return f(beginOffset, endOffset);
}
String toString() => 'SourceSpan($uri, $begin, $end)';
}