1 /*

     2  * Copyright 2009 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Sun designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Sun in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    22  * CA 95054 USA or visit www.sun.com if you need additional information or

    23  * have any questions.

    24  */

    25 

    26 package com.sun.tools.javap;

    27 

    28 import com.sun.tools.classfile.AccessFlags;

    29 import java.util.HashMap;

    30 import java.util.Map;

    31 

    32 import com.sun.tools.classfile.Attribute;

    33 import com.sun.tools.classfile.Code_attribute;

    34 import com.sun.tools.classfile.ConstantPool;

    35 import com.sun.tools.classfile.ConstantPoolException;

    36 import com.sun.tools.classfile.Descriptor;

    37 import com.sun.tools.classfile.Descriptor.InvalidDescriptor;

    38 import com.sun.tools.classfile.Instruction;

    39 import com.sun.tools.classfile.Method;

    40 import com.sun.tools.classfile.StackMapTable_attribute;

    41 import com.sun.tools.classfile.StackMapTable_attribute.*;

    42 

    43 import static com.sun.tools.classfile.StackMapTable_attribute.verification_type_info.*;

    44 

    45 /**

    46  * Annotate instructions with stack map.

    47  *

    48  *  <p><b>This is NOT part of any API supported by Sun Microsystems.  If

    49  *  you write code that depends on this, you do so at your own risk.

    50  *  This code and its internal interfaces are subject to change or

    51  *  deletion without notice.</b>

    52  */

    53 public class StackMapWriter extends InstructionDetailWriter {

    54     static StackMapWriter instance(Context context) {

    55         StackMapWriter instance = context.get(StackMapWriter.class);

    56         if (instance == null)

    57             instance = new StackMapWriter(context);

    58         return instance;

    59     }

    60 

    61     protected StackMapWriter(Context context) {

    62         super(context);

    63         context.put(StackMapWriter.class, this);

    64         classWriter = ClassWriter.instance(context);

    65     }

    66 

    67     public void reset(Code_attribute attr) {

    68         setStackMap((StackMapTable_attribute) attr.attributes.get(Attribute.StackMapTable));

    69     }

    70 

    71     void setStackMap(StackMapTable_attribute attr) {

    72         if (attr == null) {

    73             map = null;

    74             return;

    75         }

    76 

    77         Method m = classWriter.getMethod();

    78         Descriptor d = m.descriptor;

    79         String[] args;

    80         try {

    81             ConstantPool cp = classWriter.getClassFile().constant_pool;

    82             String argString = d.getParameterTypes(cp);

    83             args = argString.substring(1, argString.length() - 1).split("[, ]+");

    84         } catch (ConstantPoolException e) {

    85             return;

    86         } catch (InvalidDescriptor e) {

    87             return;

    88         }

    89         boolean isStatic = m.access_flags.is(AccessFlags.ACC_STATIC);

    90 

    91         verification_type_info[] initialLocals = new verification_type_info[(isStatic ? 0 : 1) + args.length];

    92         if (!isStatic)

    93             initialLocals[0] = new CustomVerificationTypeInfo("this");

    94         for (int i = 0; i < args.length; i++) {

    95             initialLocals[(isStatic ? 0 : 1) + i] =

    96                     new CustomVerificationTypeInfo(args[i].replace(".", "/"));

    97         }

    98 

    99         map = new HashMap<Integer, StackMap>();

   100         StackMapBuilder builder = new StackMapBuilder();

   101 

   102         // using -1 as the pc for the initial frame effectively compensates for

   103         // the difference in behavior for the first stack map frame (where the

   104         // pc offset is just offset_delta) compared to subsequent frames (where

   105         // the pc offset is always offset_delta+1).

   106         int pc = -1;

   107 

   108         map.put(pc, new StackMap(initialLocals, empty));

   109 

   110         for (int i = 0; i < attr.entries.length; i++)

   111             pc = attr.entries[i].accept(builder, pc);

   112     }

   113 

   114     public void writeInitialDetails() {

   115         writeDetails(-1);

   116     }

   117 

   118     public void writeDetails(Instruction instr) {

   119         writeDetails(instr.getPC());

   120     }

   121 

   122     private void writeDetails(int pc) {

   123         if (map == null)

   124             return;

   125 

   126         StackMap m = map.get(pc);

   127         if (m != null) {

   128             print("StackMap locals: ", m.locals);

   129             print("StackMap stack: ", m.stack);

   130         }

   131 

   132     }

   133 

   134     void print(String label, verification_type_info[] entries) {

   135         print(label);

   136         for (int i = 0; i < entries.length; i++) {

   137             print(" ");

   138             print(entries[i]);

   139         }

   140         println();

   141     }

   142 

   143     void print(verification_type_info entry) {

   144         if (entry == null) {

   145             print("ERROR");

   146             return;

   147         }

   148 

   149         switch (entry.tag) {

   150             case -1:

   151                 print(((CustomVerificationTypeInfo) entry).text);

   152                 break;

   153 

   154             case ITEM_Top:

   155                 print("top");

   156                 break;

   157 

   158             case ITEM_Integer:

   159                 print("int");

   160                 break;

   161 

   162             case ITEM_Float:

   163                 print("float");

   164                 break;

   165 

   166             case ITEM_Long:

   167                 print("long");

   168                 break;

   169 

   170             case ITEM_Double:

   171                 print("double");

   172                 break;

   173 

   174             case ITEM_Null:

   175                 print("null");

   176                 break;

   177 

   178             case ITEM_UninitializedThis:

   179                 print("uninit_this");

   180                 break;

   181 

   182             case ITEM_Object:

   183                 try {

   184                     ConstantPool cp = classWriter.getClassFile().constant_pool;

   185                     ConstantPool.CONSTANT_Class_info class_info = cp.getClassInfo(((Object_variable_info) entry).cpool_index);

   186                     print(cp.getUTF8Value(class_info.name_index));

   187                 } catch (ConstantPoolException e) {

   188                     print("??");

   189                 }

   190                 break;

   191 

   192             case ITEM_Uninitialized:

   193                 print(((Uninitialized_variable_info) entry).offset);

   194                 break;

   195         }

   196 

   197     }

   198 

   199     private Map<Integer, StackMap> map;

   200     private ClassWriter classWriter;

   201 

   202     class StackMapBuilder

   203             implements StackMapTable_attribute.stack_map_frame.Visitor<Integer, Integer> {

   204 

   205         public Integer visit_same_frame(same_frame frame, Integer pc) {

   206             int new_pc = pc + frame.getOffsetDelta() + 1;

   207             StackMap m = map.get(pc);

   208             assert (m != null);

   209             map.put(new_pc, m);

   210             return new_pc;

   211         }

   212 

   213         public Integer visit_same_locals_1_stack_item_frame(same_locals_1_stack_item_frame frame, Integer pc) {

   214             int new_pc = pc + frame.getOffsetDelta() + 1;

   215             StackMap prev = map.get(pc);

   216             assert (prev != null);

   217             StackMap m = new StackMap(prev.locals, frame.stack);

   218             map.put(new_pc, m);

   219             return new_pc;

   220         }

   221 

   222         public Integer visit_same_locals_1_stack_item_frame_extended(same_locals_1_stack_item_frame_extended frame, Integer pc) {

   223             int new_pc = pc + frame.getOffsetDelta() + 1;

   224             StackMap prev = map.get(pc);

   225             assert (prev != null);

   226             StackMap m = new StackMap(prev.locals, frame.stack);

   227             map.put(new_pc, m);

   228             return new_pc;

   229         }

   230 

   231         public Integer visit_chop_frame(chop_frame frame, Integer pc) {

   232             int new_pc = pc + frame.getOffsetDelta() + 1;

   233             StackMap prev = map.get(pc);

   234             assert (prev != null);

   235             int k = 251 - frame.frame_type;

   236             verification_type_info[] new_locals = new verification_type_info[prev.locals.length - k];

   237             System.arraycopy(prev.locals, 0, new_locals, 0, new_locals.length);

   238             StackMap m = new StackMap(new_locals, empty);

   239             map.put(new_pc, m);

   240             return new_pc;

   241         }

   242 

   243         public Integer visit_same_frame_extended(same_frame_extended frame, Integer pc) {

   244             int new_pc = pc + frame.getOffsetDelta();

   245             StackMap m = map.get(pc);

   246             assert (m != null);

   247             map.put(new_pc, m);

   248             return new_pc;

   249         }

   250 

   251         public Integer visit_append_frame(append_frame frame, Integer pc) {

   252             int new_pc = pc + frame.getOffsetDelta() + 1;

   253             StackMap prev = map.get(pc);

   254             assert (prev != null);

   255             verification_type_info[] new_locals = new verification_type_info[prev.locals.length + frame.locals.length];

   256             System.arraycopy(prev.locals, 0, new_locals, 0, prev.locals.length);

   257             System.arraycopy(frame.locals, 0, new_locals, prev.locals.length, frame.locals.length);

   258             StackMap m = new StackMap(new_locals, empty);

   259             map.put(new_pc, m);

   260             return new_pc;

   261         }

   262 

   263         public Integer visit_full_frame(full_frame frame, Integer pc) {

   264             int new_pc = pc + frame.getOffsetDelta() + 1;

   265             StackMap m = new StackMap(frame.locals, frame.stack);

   266             map.put(new_pc, m);

   267             return new_pc;

   268         }

   269 

   270     }

   271 

   272     class StackMap {

   273         StackMap(verification_type_info[] locals, verification_type_info[] stack) {

   274             this.locals = locals;

   275             this.stack = stack;

   276         }

   277 

   278         private final verification_type_info[] locals;

   279         private final verification_type_info[] stack;

   280     }

   281 

   282     class CustomVerificationTypeInfo extends verification_type_info {

   283         public CustomVerificationTypeInfo(String text) {

   284             super(-1);

   285             this.text = text;

   286         }

   287         private String text;

   288     }

   289 

   290     private final verification_type_info[] empty = { };

   291 }