[Truffle] Added support for $@ global variable.

jruby · Mar 12, 2015 · 2ef7d6e · 2ef7d6e
1 parent b84a3fd
commit 2ef7d6e
Showing 3 changed files with 109 additions and 0 deletions.
diff --git a/truffle/src/main/java/org/jruby/truffle/nodes/globals/ReadLastBacktraceNode.java b/truffle/src/main/java/org/jruby/truffle/nodes/globals/ReadLastBacktraceNode.java
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2015 Oracle and/or its affiliates. All rights reserved. This
+ * code is released under a tri EPL/GPL/LGPL license. You can use it,
+ * redistribute it and/or modify it under the terms of the:
+ *
+ * Eclipse Public License version 1.0
+ * GNU General Public License version 2
+ * GNU Lesser General Public License version 2.1
+ */
+
+package org.jruby.truffle.nodes.globals;
+
+import com.oracle.truffle.api.CompilerDirectives;
+import com.oracle.truffle.api.frame.VirtualFrame;
+import com.oracle.truffle.api.source.SourceSection;
+import org.jruby.truffle.nodes.RubyNode;
+import org.jruby.truffle.nodes.dispatch.CallDispatchHeadNode;
+import org.jruby.truffle.nodes.dispatch.DispatchHeadNodeFactory;
+import org.jruby.truffle.runtime.RubyContext;
+import org.jruby.truffle.runtime.core.RubyBasicObject;
+
+public class ReadLastBacktraceNode extends RubyNode {
+
+    @Child private CallDispatchHeadNode getBacktraceNode;
+
+    public ReadLastBacktraceNode(RubyContext context, SourceSection sourceSection) {
+        super(context, sourceSection);
+    }
+
+    @Override
+    public Object execute(VirtualFrame frame) {
+        // TODO (nirvdrum 12-Mar-15) $! should be thread-local.
+        final RubyBasicObject globals = getContext().getCoreLibrary().getGlobalVariablesObject();
+        final Object lastException = globals.getOperations().getInstanceVariable(globals, "$!");
+
+        if (lastException == getContext().getCoreLibrary().getNilObject()) {
+            return getContext().getCoreLibrary().getNilObject();
+        }
+
+        if (getBacktraceNode == null) {
+            CompilerDirectives.transferToInterpreter();
+            getBacktraceNode = insert(DispatchHeadNodeFactory.createMethodCall(getContext()));
+        }
+
+        return getBacktraceNode.call(frame, lastException, "backtrace", null);
+    }
+}
diff --git a/truffle/src/main/java/org/jruby/truffle/nodes/globals/UpdateLastBacktraceNode.java b/truffle/src/main/java/org/jruby/truffle/nodes/globals/UpdateLastBacktraceNode.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2015 Oracle and/or its affiliates. All rights reserved. This
+ * code is released under a tri EPL/GPL/LGPL license. You can use it,
+ * redistribute it and/or modify it under the terms of the:
+ *
+ * Eclipse Public License version 1.0
+ * GNU General Public License version 2
+ * GNU Lesser General Public License version 2.1
+ */
+
+package org.jruby.truffle.nodes.globals;
+
+import com.oracle.truffle.api.CompilerDirectives;
+import com.oracle.truffle.api.frame.VirtualFrame;
+import com.oracle.truffle.api.source.SourceSection;
+import org.jruby.truffle.nodes.RubyNode;
+import org.jruby.truffle.nodes.dispatch.CallDispatchHeadNode;
+import org.jruby.truffle.nodes.dispatch.DispatchHeadNodeFactory;
+import org.jruby.truffle.runtime.RubyContext;
+import org.jruby.truffle.runtime.control.RaiseException;
+import org.jruby.truffle.runtime.core.RubyBasicObject;
+
+public class UpdateLastBacktraceNode extends RubyNode {
+
+    @Child private RubyNode child;
+    @Child private CallDispatchHeadNode setBacktraceNode;
+
+    public UpdateLastBacktraceNode(RubyContext context, SourceSection sourceSection, RubyNode child) {
+        super(context, sourceSection);
+        this.child = child;
+    }
+
+    @Override
+    public Object execute(VirtualFrame frame) {
+        // TODO (nirvdrum 12-Mar-15) $! should be thread-local.
+        final RubyBasicObject globals = getContext().getCoreLibrary().getGlobalVariablesObject();
+        final Object lastException = globals.getOperations().getInstanceVariable(globals, "$!");
+
+        if (lastException == getContext().getCoreLibrary().getNilObject()) {
+            CompilerDirectives.transferToInterpreter();
+            throw new RaiseException(getContext().getCoreLibrary().argumentError("$! is not set", this));
+        }
+
+        if (setBacktraceNode == null) {
+            CompilerDirectives.transferToInterpreter();
+            setBacktraceNode = insert(DispatchHeadNodeFactory.createMethodCall(getContext()));
+        }
+
+        final Object newBacktrace = child.execute(frame);
+        setBacktraceNode.call(frame, lastException, "set_backtrace", null, newBacktrace);
+
+        return newBacktrace;
+    }
+}
diff --git a/truffle/src/main/java/org/jruby/truffle/translator/BodyTranslator.java b/truffle/src/main/java/org/jruby/truffle/translator/BodyTranslator.java
@@ -1351,6 +1351,10 @@ public RubyNode translateGlobalAsgnNode(org.jruby.ast.GlobalAsgnNode node, RubyN
             rhs = new CheckStdoutVariableTypeNode(context, sourceSection, rhs);
         } else if (name.equals("$VERBOSE")) {
             rhs = new UpdateVerbosityNode(context, sourceSection, rhs);
+        } else if (name.equals("$@")) {
+            // $@ is a special-case and doesn't write directly to an ivar field in the globals object.
+            // Instead, it writes to the backtrace field of the thread-local $! value.
+            return new UpdateLastBacktraceNode(context, sourceSection, rhs);
         }
 
         if (readOnlyGlobalVariables.contains(name)) {
@@ -1417,6 +1421,10 @@ public RubyNode visitGlobalVarNode(org.jruby.ast.GlobalVarNode node) {
         } else if (THREAD_LOCAL_GLOBAL_VARIABLES.contains(name)) {
             final ThreadLocalObjectNode threadLocalVariablesObjectNode = new ThreadLocalObjectNode(context, sourceSection);
             return new ReadInstanceVariableNode(context, sourceSection, name, threadLocalVariablesObjectNode, true);
+        } else if (name.equals("$@")) {
+            // $@ is a special-case and doesn't read directly from an ivar field in the globals object.
+            // Instead, it reads the backtrace field of the thread-local $! value.
+            return new ReadLastBacktraceNode(context, sourceSection);
         } else {
             final ObjectLiteralNode globalVariablesObjectNode = new ObjectLiteralNode(context, sourceSection, context.getCoreLibrary().getGlobalVariablesObject());
             return new ReadInstanceVariableNode(context, sourceSection, name, globalVariablesObjectNode, true);