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Diffstat (limited to 'tools/external/asm/org/objectweb/asm/attrs/StackMapAttribute.java')
| -rw-r--r-- | tools/external/asm/org/objectweb/asm/attrs/StackMapAttribute.java | 378 |
1 files changed, 378 insertions, 0 deletions
diff --git a/tools/external/asm/org/objectweb/asm/attrs/StackMapAttribute.java b/tools/external/asm/org/objectweb/asm/attrs/StackMapAttribute.java new file mode 100644 index 000000000..4df2f7dde --- /dev/null +++ b/tools/external/asm/org/objectweb/asm/attrs/StackMapAttribute.java @@ -0,0 +1,378 @@ +/** + * ASM: a very small and fast Java bytecode manipulation framework + * Copyright (c) 2000-2005 INRIA, France Telecom + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF + * THE POSSIBILITY OF SUCH DAMAGE. + */ +package org.objectweb.asm.attrs; + +import java.util.ArrayList; +import java.util.HashSet; +import java.util.Iterator; +import java.util.List; +import java.util.Set; + +import org.objectweb.asm.Attribute; +import org.objectweb.asm.ByteVector; +import org.objectweb.asm.ClassReader; +import org.objectweb.asm.ClassWriter; +import org.objectweb.asm.Label; + +/** + * StackMapAttribute is used by CDLC preverifier. Definition is given in + * appendix "CLDC Byte Code Typechecker Specification" from CDLC 1.1 + * specification. <p> <i>Note that this implementation does not calculate + * StackMapFrame structures from the method bytecode. If method code is changed + * or generated from scratch, then developer is responsible to prepare a correct + * StackMapFrame structures.</i> <p> The format of the stack map in the class + * file is given below. In the following, <ul> <li>if the length of the + * method's byte code1 is 65535 or less, then <tt>uoffset</tt> represents the + * type u2; otherwise <tt>uoffset</tt> represents the type u4.</li> <li>If + * the maximum number of local variables for the method is 65535 or less, then + * <tt>ulocalvar</tt> represents the type u2; otherwise <tt>ulocalvar</tt> + * represents the type u4.</li> <li>If the maximum size of the operand stack + * is 65535 or less, then <tt>ustack</tt> represents the type u2; otherwise + * ustack represents the type u4.</li> </ul> + * + * <pre> + * stack_map { // attribute StackMap + * u2 attribute_name_index; + * u4 attribute_length + * uoffset number_of_entries; + * stack_map_frame entries[number_of_entries]; + * } + * </pre> + * + * Each stack map frame has the following format: + * + * <pre> + * stack_map_frame { + * uoffset offset; + * ulocalvar number_of_locals; + * verification_type_info locals[number_of_locals]; + * ustack number_of_stack_items; + * verification_type_info stack[number_of_stack_items]; + * } + * </pre> + * + * The <tt>verification_type_info</tt> structure consists of a one-byte tag + * followed by zero or more bytes, giving more information about the tag. Each + * <tt>verification_type_info</tt> structure specifies the verification type + * of one or two locations. + * + * <pre> + * union verification_type_info { + * Top_variable_info; + * Integer_variable_info; + * Float_variable_info; + * Long_variable_info; + * Double_variable_info; + * Null_variable_info; + * UninitializedThis_variable_info; + * Object_variable_info; + * Uninitialized_variable_info; + * } + * + * Top_variable_info { + * u1 tag = ITEM_Top; // 0 + * } + * + * Integer_variable_info { + * u1 tag = ITEM_Integer; // 1 + * } + * + * Float_variable_info { + * u1 tag = ITEM_Float; // 2 + * } + * + * Long_variable_info { + * u1 tag = ITEM_Long; // 4 + * } + * + * Double_variable_info { + * u1 tag = ITEM_Double; // 3 + * } + * + * Null_variable_info { + * u1 tag = ITEM_Null; // 5 + * } + * + * UninitializedThis_variable_info { + * u1 tag = ITEM_UninitializedThis; // 6 + * } + * + * Object_variable_info { + * u1 tag = ITEM_Object; // 7 + * u2 cpool_index; + * } + * + * Uninitialized_variable_info { + * u1 tag = ITEM_Uninitialized // 8 + * uoffset offset; + * } + * </pre> + * + * @see <a href="http://www.jcp.org/en/jsr/detail?id=139">JSR 139 : Connected + * Limited Device Configuration 1.1</a> + * + * @author Eugene Kuleshov + */ +public class StackMapAttribute extends Attribute { + + static final int MAX_SIZE = 65535; + + /** + * A List of <code>StackMapFrame</code> instances. + */ + public List frames = new ArrayList(); + + public StackMapAttribute() { + super("StackMap"); + } + + public StackMapAttribute(List frames) { + this(); + this.frames = frames; + } + + public List getFrames() { + return frames; + } + + public StackMapFrame getFrame(Label label) { + for (int i = 0; i < frames.size(); i++) { + StackMapFrame frame = (StackMapFrame) frames.get(i); + if (frame.label == label) { + return frame; + } + } + return null; + } + + public boolean isUnknown() { + return false; + } + + public boolean isCodeAttribute() { + return true; + } + + protected Attribute read( + ClassReader cr, + int off, + int len, + char[] buf, + int codeOff, + Label[] labels) + { + StackMapAttribute attr = new StackMapAttribute(); + // note that this is not the size of Code attribute + boolean isExtCodeSize = cr.readInt(codeOff + 4) > MAX_SIZE; + boolean isExtLocals = cr.readUnsignedShort(codeOff + 2) > MAX_SIZE; + boolean isExtStack = cr.readUnsignedShort(codeOff) > MAX_SIZE; + + int size = 0; + if (isExtCodeSize) { + size = cr.readInt(off); + off += 4; + } else { + size = cr.readUnsignedShort(off); + off += 2; + } + for (int i = 0; i < size; i++) { + int offset; + if (isExtCodeSize) { + offset = cr.readInt(off); + off += 4; + } else { + offset = cr.readUnsignedShort(off); + off += 2; + } + + Label label = getLabel(offset, labels); + List locals = new ArrayList(); + List stack = new ArrayList(); + + off = readTypeInfo(cr, + off, + locals, + labels, + buf, + isExtLocals, + isExtCodeSize); + off = readTypeInfo(cr, + off, + stack, + labels, + buf, + isExtStack, + isExtCodeSize); + + attr.frames.add(new StackMapFrame(label, locals, stack)); + } + return attr; + } + + private int readTypeInfo( + ClassReader cr, + int off, + List info, + Label[] labels, + char[] buf, + boolean isExt, + boolean isExtCode) + { + int n = 0; + if (isExt) { + n = cr.readInt(off); + off += 4; + } else { + n = cr.readUnsignedShort(off); + off += 2; + } + for (int j = 0; j < n; j++) { + int itemType = cr.readByte(off++); + StackMapType typeInfo = StackMapType.getTypeInfo(itemType); + info.add(typeInfo); + switch (itemType) { + case StackMapType.ITEM_Object: // + typeInfo.setObject(cr.readClass(off, buf)); + off += 2; + break; + case StackMapType.ITEM_Uninitialized: // + int offset; + if (isExtCode) { + offset = cr.readInt(off); + off += 4; + } else { + offset = cr.readUnsignedShort(off); + off += 2; + } + typeInfo.setLabel(getLabel(offset, labels)); + break; + } + } + return off; + } + + private void writeTypeInfo(ByteVector bv, ClassWriter cw, List info, int max) + { + if (max > StackMapAttribute.MAX_SIZE) { + bv.putInt(info.size()); + } else { + bv.putShort(info.size()); + } + for (int j = 0; j < info.size(); j++) { + StackMapType typeInfo = (StackMapType) info.get(j); + bv.putByte(typeInfo.getType()); + switch (typeInfo.getType()) { + case StackMapType.ITEM_Object: // + bv.putShort(cw.newClass(typeInfo.getObject())); + break; + + case StackMapType.ITEM_Uninitialized: // + bv.putShort(typeInfo.getLabel().getOffset()); + break; + + } + } + } + + private Label getLabel(int offset, Label[] labels) { + Label l = labels[offset]; + if (l != null) { + return l; + } + return labels[offset] = new Label(); + } + + protected ByteVector write( + ClassWriter cw, + byte[] code, + int len, + int maxStack, + int maxLocals) + { + ByteVector bv = new ByteVector(); + if (code != null && code.length > MAX_SIZE) { // TODO verify value + bv.putInt(frames.size()); + } else { + bv.putShort(frames.size()); + } + for (int i = 0; i < frames.size(); i++) { + writeFrame((StackMapFrame) frames.get(i), + cw, + maxStack, + maxLocals, + bv); + } + return bv; + } + + protected Label[] getLabels() { + HashSet labels = new HashSet(); + for (int i = 0; i < frames.size(); i++) { + getFrameLabels((StackMapFrame) frames.get(i), labels); + } + return (Label[]) labels.toArray(new Label[labels.size()]); + } + + private void writeFrame( + StackMapFrame frame, + ClassWriter cw, + int maxStack, + int maxLocals, + ByteVector bv) + { + bv.putShort(frame.label.getOffset()); + writeTypeInfo(bv, cw, frame.locals, maxLocals); + writeTypeInfo(bv, cw, frame.stack, maxStack); + } + + private void getFrameLabels(StackMapFrame frame, Set labels) { + labels.add(frame.label); + getTypeInfoLabels(labels, frame.locals); + getTypeInfoLabels(labels, frame.stack); + } + + private void getTypeInfoLabels(Set labels, List info) { + for (Iterator it = info.iterator(); it.hasNext();) { + StackMapType typeInfo = (StackMapType) it.next(); + if (typeInfo.getType() == StackMapType.ITEM_Uninitialized) { + labels.add(typeInfo.getLabel()); + } + } + } + + public String toString() { + StringBuffer sb = new StringBuffer("StackMap["); + for (int i = 0; i < frames.size(); i++) { + sb.append('\n').append('[').append(frames.get(i)).append(']'); + } + sb.append("\n]"); + return sb.toString(); + } +} |