ojluni/src/main/java/java/lang/LiveStackFrame.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2015, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * 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
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * 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.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package java.lang;

 import java.lang.StackWalker.StackFrame;
 import java.util.EnumSet;
 import java.util.Set;

 import static java.lang.StackWalker.ExtendedOption.LOCALS_AND_OPERANDS;

 /**
  * <em>UNSUPPORTED</em> This interface is intended to be package-private
  * or move to an internal package.<p>
  *
  * {@code LiveStackFrame} represents a frame storing data and partial results.
  * Each frame has its own array of local variables (JVMS section 2.6.1),
  * its own operand stack (JVMS section 2.6.2) for a method invocation.
  *
  * @jvms 2.6 Frames
  */
 /* package-private */
 interface LiveStackFrame extends StackFrame {
     /**
      * Return the monitors held by this stack frame. This method returns
      * an empty array if no monitor is held by this stack frame.
      *
      * @return the monitors held by this stack frames
      */
     public Object[] getMonitors();

     /**
      * Gets the local variable array of this stack frame.
      *
      * <p>A single local variable can hold a value of type boolean, byte, char,
      * short, int, float, reference or returnAddress.  A pair of local variables
      * can hold a value of type long or double (JVMS section 2.6.1).  Primitive
      * locals are represented in the returned array as {@code PrimitiveSlot}s,
      * with longs and doubles occupying a pair of consecutive
      * {@code PrimitiveSlot}s.
      *
      * <p>The current VM implementation does not provide specific type
      * information for primitive locals.  This method simply returns the raw
      * contents of the VM's primitive locals on a best-effort basis, without
      * indicating a specific type.
      *
      * <p>The returned array may contain null entries for local variables that
      * are not live.
      *
      * @implNote
      * <p> The specific subclass of {@code PrimitiveSlot} will reflect the
      * underlying architecture, and will be either {@code PrimitiveSlot32} or
      * {@code PrimitiveSlot64}.
      *
      * <p>How a long or double value is stored in the pair of
      * {@code PrimitiveSlot}s can vary based on the underlying architecture and
      * VM implementation.  On 32-bit architectures, long/double values are split
      * between the two {@code PrimitiveSlot32}s.
      * On 64-bit architectures, the entire value may be stored in one of the
      * {@code PrimitiveSlot64}s, with the other {@code PrimitiveSlot64} being
      * unused.
      *
      * <p>The contents of the unused, high-order portion of a
      * {@code PrimitiveSlot64} (when storing a primitive other than a long or
      * double) is unspecified.  In particular, the unused bits are not
      * necessarily zeroed out.
      *
      * @return  the local variable array of this stack frame.
      */
     public Object[] getLocals();

     /**
      * Gets the operand stack of this stack frame.
      *
      * <p>
      * The 0-th element of the returned array represents the top of the operand stack.
      * This method returns an empty array if the operand stack is empty.
      *
      * <p>Each entry on the operand stack can hold a value of any Java Virtual
      * Machine Type.
      * For a value of primitive type, the element in the returned array is
      * a {@link PrimitiveSlot} object; otherwise, the element is the {@code Object}
      * on the operand stack.
      *
      * @return the operand stack of this stack frame.
      */
     public Object[] getStack();

     /**
      * <em>UNSUPPORTED</em> This interface is intended to be package-private
      * or moved to an internal package.<p>
      *
      * Represents a local variable or an entry on the operand stack whose value is
      * of primitive type.
      */
     public abstract class PrimitiveSlot {
         /**
          * Constructor.
          */
         PrimitiveSlot() {}

         /**
          * Returns the size, in bytes, of the slot.
          */
         public abstract int size();

         /**
          * Returns the int value if this primitive value is of size 4
          * @return the int value if this primitive value is of size 4
          *
          * @throws UnsupportedOperationException if this primitive value is not
          * of size 4.
          */
         public int intValue() {
             throw new UnsupportedOperationException("this " + size() + "-byte primitive");
         }

         /**
          * Returns the long value if this primitive value is of size 8
          * @return the long value if this primitive value is of size 8
          *
          * @throws UnsupportedOperationException if this primitive value is not
          * of size 8.
          */
         public long longValue() {
             throw new UnsupportedOperationException("this " + size() + "-byte primitive");
         }
     }


     /**
      * Gets {@code StackWalker} that can get locals and operands.
      *
      * @throws SecurityException if the security manager is present and
      * denies access to {@code RuntimePermission("liveStackFrames")}
      */
     public static StackWalker getStackWalker() {
         return getStackWalker(EnumSet.noneOf(StackWalker.Option.class));
     }

     /**
      * Gets a {@code StackWalker} instance with the given options specifying
      * the stack frame information it can access, and which will traverse at most
      * the given {@code maxDepth} number of stack frames.  If no option is
      * specified, this {@code StackWalker} obtains the method name and
      * the class name with all
      * {@linkplain StackWalker.Option#SHOW_HIDDEN_FRAMES hidden frames} skipped.
      * The returned {@code StackWalker} can get locals and operands.
      *
      * @param options stack walk {@link StackWalker.Option options}
      *
      * @throws SecurityException if the security manager is present and
      * it denies access to {@code RuntimePermission("liveStackFrames")};
      * or if the given {@code options} contains
      * {@link StackWalker.Option#RETAIN_CLASS_REFERENCE Option.RETAIN_CLASS_REFERENCE}
      * and it denies access to {@code RuntimePermission("getStackWalkerWithClassReference")}.
      */
     public static StackWalker getStackWalker(Set<StackWalker.Option> options) {
         @SuppressWarnings("removal")
         SecurityManager sm = System.getSecurityManager();
         if (sm != null) {
             sm.checkPermission(new RuntimePermission("liveStackFrames"));
         }
         return StackWalker.newInstance(options, LOCALS_AND_OPERANDS);
     }
 }
	/*
	* Copyright (c) 2015, 2021, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* 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
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* 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.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/
	package java.lang;

	import java.lang.StackWalker.StackFrame;
	import java.util.EnumSet;
	import java.util.Set;

	import static java.lang.StackWalker.ExtendedOption.LOCALS_AND_OPERANDS;

	/**
	* <em>UNSUPPORTED</em> This interface is intended to be package-private
	* or move to an internal package.<p>
	*
	* {@code LiveStackFrame} represents a frame storing data and partial results.
	* Each frame has its own array of local variables (JVMS section 2.6.1),
	* its own operand stack (JVMS section 2.6.2) for a method invocation.
	*
	* @jvms 2.6 Frames
	*/
	/* package-private */
	interface LiveStackFrame extends StackFrame {
	/**
	* Return the monitors held by this stack frame. This method returns
	* an empty array if no monitor is held by this stack frame.
	*
	* @return the monitors held by this stack frames
	*/
	public Object[] getMonitors();

	/**
	* Gets the local variable array of this stack frame.
	*
	* <p>A single local variable can hold a value of type boolean, byte, char,
	* short, int, float, reference or returnAddress. A pair of local variables
	* can hold a value of type long or double (JVMS section 2.6.1). Primitive
	* locals are represented in the returned array as {@code PrimitiveSlot}s,
	* with longs and doubles occupying a pair of consecutive
	* {@code PrimitiveSlot}s.
	*
	* <p>The current VM implementation does not provide specific type
	* information for primitive locals. This method simply returns the raw
	* contents of the VM's primitive locals on a best-effort basis, without
	* indicating a specific type.
	*
	* <p>The returned array may contain null entries for local variables that
	* are not live.
	*
	* @implNote
	* <p> The specific subclass of {@code PrimitiveSlot} will reflect the
	* underlying architecture, and will be either {@code PrimitiveSlot32} or
	* {@code PrimitiveSlot64}.
	*
	* <p>How a long or double value is stored in the pair of
	* {@code PrimitiveSlot}s can vary based on the underlying architecture and
	* VM implementation. On 32-bit architectures, long/double values are split
	* between the two {@code PrimitiveSlot32}s.
	* On 64-bit architectures, the entire value may be stored in one of the
	* {@code PrimitiveSlot64}s, with the other {@code PrimitiveSlot64} being
	* unused.
	*
	* <p>The contents of the unused, high-order portion of a
	* {@code PrimitiveSlot64} (when storing a primitive other than a long or
	* double) is unspecified. In particular, the unused bits are not
	* necessarily zeroed out.
	*
	* @return the local variable array of this stack frame.
	*/
	public Object[] getLocals();

	/**
	* Gets the operand stack of this stack frame.
	*
	* <p>
	* The 0-th element of the returned array represents the top of the operand stack.
	* This method returns an empty array if the operand stack is empty.
	*
	* <p>Each entry on the operand stack can hold a value of any Java Virtual
	* Machine Type.
	* For a value of primitive type, the element in the returned array is
	* a {@link PrimitiveSlot} object; otherwise, the element is the {@code Object}
	* on the operand stack.
	*
	* @return the operand stack of this stack frame.
	*/
	public Object[] getStack();

	/**
	* <em>UNSUPPORTED</em> This interface is intended to be package-private
	* or moved to an internal package.<p>
	*
	* Represents a local variable or an entry on the operand stack whose value is
	* of primitive type.
	*/
	public abstract class PrimitiveSlot {
	/**
	* Constructor.
	*/
	PrimitiveSlot() {}

	/**
	* Returns the size, in bytes, of the slot.
	*/
	public abstract int size();

	/**
	* Returns the int value if this primitive value is of size 4
	* @return the int value if this primitive value is of size 4
	*
	* @throws UnsupportedOperationException if this primitive value is not
	* of size 4.
	*/
	public int intValue() {
	throw new UnsupportedOperationException("this " + size() + "-byte primitive");
	}

	/**
	* Returns the long value if this primitive value is of size 8
	* @return the long value if this primitive value is of size 8
	*
	* @throws UnsupportedOperationException if this primitive value is not
	* of size 8.
	*/
	public long longValue() {
	throw new UnsupportedOperationException("this " + size() + "-byte primitive");
	}
	}


	/**
	* Gets {@code StackWalker} that can get locals and operands.
	*
	* @throws SecurityException if the security manager is present and
	* denies access to {@code RuntimePermission("liveStackFrames")}
	*/
	public static StackWalker getStackWalker() {
	return getStackWalker(EnumSet.noneOf(StackWalker.Option.class));
	}

	/**
	* Gets a {@code StackWalker} instance with the given options specifying
	* the stack frame information it can access, and which will traverse at most
	* the given {@code maxDepth} number of stack frames. If no option is
	* specified, this {@code StackWalker} obtains the method name and
	* the class name with all
	* {@linkplain StackWalker.Option#SHOW_HIDDEN_FRAMES hidden frames} skipped.
	* The returned {@code StackWalker} can get locals and operands.
	*
	* @param options stack walk {@link StackWalker.Option options}
	*
	* @throws SecurityException if the security manager is present and
	* it denies access to {@code RuntimePermission("liveStackFrames")};
	* or if the given {@code options} contains
	* {@link StackWalker.Option#RETAIN_CLASS_REFERENCE Option.RETAIN_CLASS_REFERENCE}
	* and it denies access to {@code RuntimePermission("getStackWalkerWithClassReference")}.
	*/
	public static StackWalker getStackWalker(Set<StackWalker.Option> options) {
	@SuppressWarnings("removal")
	SecurityManager sm = System.getSecurityManager();
	if (sm != null) {
	sm.checkPermission(new RuntimePermission("liveStackFrames"));
	}
	return StackWalker.newInstance(options, LOCALS_AND_OPERANDS);
	}
	}