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/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
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*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package com.oracle.truffle.api.instrumentation;
import java.io.IOException;
import java.util.Collection;
import java.util.Iterator;
import java.util.Objects;
import com.oracle.truffle.api.CallTarget;
import com.oracle.truffle.api.CompilerAsserts;
import com.oracle.truffle.api.CompilerDirectives;
import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
import com.oracle.truffle.api.TruffleLanguage.Env;
import com.oracle.truffle.api.frame.VirtualFrame;
import com.oracle.truffle.api.instrumentation.InstrumentationHandler.AccessorInstrumentHandler;
import com.oracle.truffle.api.nodes.LanguageInfo;
import com.oracle.truffle.api.nodes.Node;
import com.oracle.truffle.api.nodes.RootNode;
import com.oracle.truffle.api.source.Source;
import com.oracle.truffle.api.source.SourceSection;
/**
* Represents the context of an execution event.
*
* Instances of {@link EventContext} should be neither stored, cached nor hashed. One exception is
* when they are stored in {@link ExecutionEventNode} implementations. The equality and hashing
* behavior is undefined.
*
* @see ExecutionEventNodeFactory
* @see ExecutionEventListener
* @since 0.12
*/
public final class EventContext {
private final ProbeNode probeNode;
private final SourceSection sourceSection;
@CompilationFinal private volatile Object nodeObject;
EventContext(ProbeNode probeNode, SourceSection sourceSection) {
this.sourceSection = sourceSection;
this.probeNode = probeNode;
}
@SuppressWarnings("unchecked")
boolean validEventContext() {
Node node = getInstrumentedNode();
if (node instanceof RootNode) {
throw new IllegalStateException("Instrumentable node must not be a root node.");
}
Object object = null;
if (node instanceof InstrumentableNode) {
object = ((InstrumentableNode) node).getNodeObject();
} else {
// legacy support
return true;
}
if (object != null) {
assert AccessorInstrumentHandler.interopAccess().isValidNodeObject(object);
}
boolean foundStandardTag = false;
for (Class clazz : StandardTags.ALL_TAGS) {
if (hasTag((Class) clazz)) {
foundStandardTag = true;
}
}
if (foundStandardTag) {
RootNode root = probeNode.getRootNode();
if (root != null && root.getSourceSection() != null) {
assert sourceSection != null : "All nodes tagged with a standard tag and with a root node that has a source section must also have a source section.";
}
}
return true;
}
ProbeNode getProbeNode() {
return probeNode;
}
/**
* Returns true if the underlying instrumented AST is tagged with a particular tag.
* The return value of {@link #hasTag(Class)} always returns the same value for a particular tag
* and {@link EventContext}. The method may be used on compiled code paths.
*
* @param tag the tag to check to check, must not be null.
* @since 0.33
*/
public boolean hasTag(Class tag) {
if (tag == null) {
CompilerDirectives.transferToInterpreter();
throw new NullPointerException();
}
Node node = getInstrumentedNode();
if (node instanceof InstrumentableNode) {
return ((InstrumentableNode) node).hasTag(tag);
} else {
// legacy support
return AccessorInstrumentHandler.nodesAccess().isTaggedWith(node, tag);
}
}
/**
* Returns a language provided object that represents the instrumented node properties. The
* returned is alwasy a valid interop object. The returned object is never null and
* always returns true for the HAS_KEYS message. Multiple calls to
* {@link #getNodeObject()} return the same node object instance.
*
* @see InstrumentableNode#getNodeObject()
* @since 0.33
*/
public Object getNodeObject() {
Object object = this.nodeObject;
if (object == null) {
CompilerDirectives.transferToInterpreterAndInvalidate();
Node node = getInstrumentedNode();
if (node instanceof InstrumentableNode) {
object = ((InstrumentableNode) node).getNodeObject();
} else {
return null;
}
if (object == null) {
object = AccessorInstrumentHandler.interopAccess().createDefaultNodeObject(node);
} else {
assert AccessorInstrumentHandler.interopAccess().isValidNodeObject(object);
}
this.nodeObject = object;
}
return object;
}
/**
* Returns the {@link SourceSection} that is being instrumented. The returned source section is
* final for each {@link EventContext} instance. The returned source section may be null if the
* node does not provide sources section.
*
*
* Performance note: this is method may be invoked in compiled code and is guaranteed to
* always return a compilation constant .
*
*
* @since 0.12
*/
public SourceSection getInstrumentedSourceSection() {
return sourceSection;
}
/**
* Accessor to the instrumented node at which the event occurred. The returned AST must not be
* mutated by the user.
*
* Performance note: this is method may be invoked in compiled code and is guaranteed to
* always return a compilation constant .
*
*
* @since 0.12
*/
@SuppressWarnings("deprecation")
public Node getInstrumentedNode() {
com.oracle.truffle.api.instrumentation.InstrumentableFactory.WrapperNode wrapper = probeNode.findWrapper();
return wrapper != null ? wrapper.getDelegateNode() : null;
}
/**
* Test if language context of the source of the event is initialized.
*
* @since 0.26
*/
public boolean isLanguageContextInitialized() {
CompilerAsserts.neverPartOfCompilation();
Node node = getInstrumentedNode();
if (node == null) {
return true;
}
RootNode root = node.getRootNode();
if (root == null) {
return true;
}
LanguageInfo languageInfo = root.getLanguageInfo();
Env env = AccessorInstrumentHandler.engineAccess().getEnvForInstrument(languageInfo);
return AccessorInstrumentHandler.langAccess().isContextInitialized(env);
}
/**
* Evaluates source of (potentially different) language using the current context. The names of
* arguments are parameters for the resulting {#link CallTarget} that allow the
* source to reference the actual parameters passed to
* {@link CallTarget#call(java.lang.Object...)}.
*
* @param source the source to evaluate
* @param argumentNames the names of {@link CallTarget#call(java.lang.Object...)} arguments that
* can be referenced from the source
* @return the call target representing the parsed result
* @throws IOException if the parsing or evaluation fails for some reason
* @since 0.12
* @deprecated Use
* {@link TruffleInstrument.Env#parseInline(com.oracle.truffle.api.source.Source, com.oracle.truffle.api.nodes.Node, com.oracle.truffle.api.frame.MaterializedFrame)}
* with {@link #getInstrumentedNode()} instead.
*/
@Deprecated
public CallTarget parseInContext(Source source, String... argumentNames) throws IOException {
Node instrumentedNode = getInstrumentedNode();
LanguageInfo languageInfo = instrumentedNode.getRootNode().getLanguageInfo();
if (languageInfo == null) {
throw new IllegalArgumentException("No language available for given node.");
}
Env env = AccessorInstrumentHandler.engineAccess().getEnvForInstrument(languageInfo);
return AccessorInstrumentHandler.langAccess().parse(env, source, instrumentedNode, argumentNames);
}
/**
* Returns the execution event node that was inserted at this location given an event binding.
* This is useful to disambiguate multiple bindings from each other when installed at the same
* source location.
*
* @param binding the binding to lookup
* @since 0.17
*/
@SuppressWarnings("cast")
public ExecutionEventNode lookupExecutionEventNode(EventBinding binding) {
if (!(binding.getElement() instanceof ExecutionEventNodeFactory)) {
// security check for unsafe generics casts
throw new IllegalArgumentException(String.format("Binding is not a subtype of %s.", ExecutionEventNodeFactory.class.getSimpleName()));
}
return probeNode.lookupExecutionEventNode(binding);
}
/**
* Returns all execution event nodes in the insertion order at this location, whose event
* bindings are contained in the given collection. This is useful to be able to sort out
* multiple bindings when installed at the same source location.
*
* @param bindings a collection of bindings to find the event nodes for at this context location
* @since 1.0
*/
public Iterator lookupExecutionEventNodes(Collection> bindings) {
return probeNode.lookupExecutionEventNodes(bindings);
}
/**
* Create an unwind throwable, that when thrown, abruptly breaks execution of a node and unwinds
* it off the execution stack. This is a a shortcut for
* {@link #createUnwind(Object, EventBinding)} with the current binding, only the event listener
* instance that threw the unwind throwable gets called onUnwind.
*
* @param info an info that is passed into
* {@link ExecutionEventListener#onUnwind(EventContext, VirtualFrame, Object)} or
* {@link ExecutionEventNode#onUnwind(VirtualFrame, Object)}. It can be used for
* arbitrary client data that help to control the unwind process.
* @see #createUnwind(Object, EventBinding)
* @since 0.31
*/
public ThreadDeath createUnwind(Object info) {
return createUnwind(info, null);
}
/**
* Create an unwind throwable, that when thrown, abruptly breaks execution of a node and unwinds
* it off the execution stack. It's to be thrown in onEnter,
* onReturnValue or onReturnExceptional methods of
* {@link ExecutionEventListener} or {@link ExecutionEventNode}, to initiate the unwind process.
* It acts in connection with
* {@link ExecutionEventListener#onUnwind(EventContext, VirtualFrame, Object)} or
* {@link ExecutionEventNode#onUnwind(VirtualFrame, Object)}. Only the event listener instance
* that is associated with the provided unwindBinding gets called
* onUnwind, use {@link #createUnwind(java.lang.Object)} to have the current event
* listener called onUnwind. Other bindings that happen to instrument the unwound
* nodes get called onReturnExceptional.
*
* The returned throwable can be kept and thrown again later to repeat the unwind process. A
* repeating unwind process is possible without deoptimization. A single throwable instance
* cannot be used on multiple threads concurrently. It can be thrown on a different thread only
* after the unwind finishes on the last thread.
*
* Usage example of forced return: {@link UnwindInstrumentationReturnSnippets#onCreate}
*
* Usage example of reenter: {@link UnwindInstrumentationReenterSnippets#onCreate}
*
* @param info an info that is passed into
* {@link ExecutionEventListener#onUnwind(EventContext, VirtualFrame, Object)} or
* {@link ExecutionEventNode#onUnwind(VirtualFrame, Object)}. It can be used for
* arbitrary client data that help to control the unwind process.
* @param unwindBinding the binding whose listener's onUnwind is to be called, or
* null to call the current listener that throws the returned throwable.
* @since 0.31
*/
@SuppressWarnings("static-method")
public ThreadDeath createUnwind(Object info, EventBinding unwindBinding) {
CompilerAsserts.neverPartOfCompilation();
return new UnwindException(info, unwindBinding);
}
/*
* TODO (chumer) a way to parse code in the current language and return something like a node
* that is directly embeddable into the AST as a @Child.
*/
/** @since 0.12 */
@Override
public String toString() {
return "EventContext[source=" + getInstrumentedSourceSection() + "]";
}
}
class UnwindInstrumentationReenterSnippets extends TruffleInstrument {
// Checkstyle: stop
// @formatter:off
@Override
// BEGIN: UnwindInstrumentationReenterSnippets#onCreate
protected void onCreate(TruffleInstrument.Env env) {
// Two event bindings are created: one for reenter, one for unwind
// Listener that reenters on unwind, attached to root nodes.
EventBinding functionReenter =
env.getInstrumenter().attachExecutionEventListener(
SourceSectionFilter.newBuilder().
tagIs(StandardTags.RootTag.class).build(),
new ExecutionEventListener() {
public Object onUnwind(EventContext context,
VirtualFrame f, Object info) {
// Reenters on unwind.
return ProbeNode.UNWIND_ACTION_REENTER;
}
public void onEnter(EventContext context, VirtualFrame f) {}
public void onReturnValue(EventContext context,
VirtualFrame f, Object result) {}
public void onReturnExceptional(EventContext context,
VirtualFrame f, Throwable ex) {}
});
// Listener that initiates unwind at line 20, attached to statements.
env.getInstrumenter().attachExecutionEventListener(
SourceSectionFilter.newBuilder().
tagIs(StandardTags.StatementTag.class).build(),
new ExecutionEventListener() {
public void onEnter(EventContext context, VirtualFrame f) {
SourceSection ss = context.getInstrumentedSourceSection();
if (ss.getStartLine() == 20) {
CompilerDirectives.transferToInterpreter();
// Unwind to nodes instrumented by functionReenter
throw context.createUnwind(null, functionReenter);
}
}
public void onReturnValue(EventContext context,
VirtualFrame f, Object result) {}
public void onReturnExceptional(EventContext context,
VirtualFrame f, Throwable ex) {}
});
}
// END: UnwindInstrumentationReenterSnippets#onCreate
// @formatter:on
}
class UnwindInstrumentationReturnSnippets extends TruffleInstrument {
// @formatter:off
@Override
// BEGIN: UnwindInstrumentationReturnSnippets#onCreate
protected void onCreate(TruffleInstrument.Env env) {
// Register a listener that checks the return value to all call nodes
// If the return value is not 42, it forces to return 42.
env.getInstrumenter().attachExecutionEventListener(
SourceSectionFilter.newBuilder().
tagIs(StandardTags.CallTag.class).build(),
new ExecutionEventListener() {
public void onEnter(EventContext context, VirtualFrame f) {}
public void onReturnValue(EventContext context,
VirtualFrame f, Object result) {
if (!Objects.equals(result, 42)) {
CompilerDirectives.transferToInterpreter();
throw context.createUnwind(42);
}
}
public Object onUnwind(EventContext context,
VirtualFrame f, Object info) {
// return 42 on unwind
return info;
}
public void onReturnExceptional(EventContext context,
VirtualFrame f, Throwable ex) {}
});
}
// END: UnwindInstrumentationReturnSnippets#onCreate
// @formatter:on
// Checkstyle: resume
}