diff options
Diffstat (limited to 'src/main/javassist/bytecode/StackMapTable.java')
| -rw-r--r-- | src/main/javassist/bytecode/StackMapTable.java | 267 |
1 files changed, 231 insertions, 36 deletions
diff --git a/src/main/javassist/bytecode/StackMapTable.java b/src/main/javassist/bytecode/StackMapTable.java index a2fecaef..cb59efa2 100644 --- a/src/main/javassist/bytecode/StackMapTable.java +++ b/src/main/javassist/bytecode/StackMapTable.java @@ -21,6 +21,7 @@ import java.io.ByteArrayOutputStream; import java.io.PrintWriter; import java.io.IOException; import java.util.Map; +import javassist.CannotCompileException; /** * <code>stack_map</code> attribute. @@ -54,8 +55,8 @@ public class StackMapTable extends AttributeInfo { * Makes a copy. * * @exception RuntimeCopyException if a <code>BadBytecode</code> - * exception is thrown, it is - * converted into + * exception is thrown while copying, + * it is converted into * <code>RuntimeCopyException</code>. * */ @@ -136,17 +137,26 @@ public class StackMapTable extends AttributeInfo { /** * A code walker for a StackMapTable attribute. */ - static class Walker { + public static class Walker { byte[] info; int numOfEntries; /** * Constructs a walker. + */ + public Walker(StackMapTable smt) { + this(smt.get()); + } + + /** + * Constructs a walker. * * @param data the <code>info</code> field of the * <code>attribute_info</code> structure. + * It can be obtained by <code>get()</code> + * in the <code>AttributeInfo</code> class. */ - public Walker(byte[] data) { + Walker(byte[] data) { info = data; numOfEntries = ByteArray.readU16bit(data, 0); } @@ -159,7 +169,7 @@ public class StackMapTable extends AttributeInfo { /** * Visits each entry of the stack map frames. */ - public final void parse() throws BadBytecode { + public void parse() throws BadBytecode { int n = numOfEntries; int pos = 2; for (int i = 0; i < n; i++) @@ -213,9 +223,9 @@ public class StackMapTable extends AttributeInfo { * field of <code>attribute_info</code> structure. * @param offsetDelta */ - public void sameFrame(int pos, int offsetDelta) {} + public void sameFrame(int pos, int offsetDelta) throws BadBytecode {} - private int sameLocals(int pos, int type) { + private int sameLocals(int pos, int type) throws BadBytecode { int offset; if (type < 128) offset = type - 64; @@ -247,7 +257,8 @@ public class StackMapTable extends AttributeInfo { * or <code>stack[0].offset</code> * if the tag is <code>UNINIT</code>. */ - public void sameLocals(int pos, int offsetDelta, int stackTag, int stackData) {} + public void sameLocals(int pos, int offsetDelta, int stackTag, int stackData) + throws BadBytecode {} /** * Invoked if the visited frame is a <code>chop_frame</code>. @@ -256,9 +267,9 @@ public class StackMapTable extends AttributeInfo { * @param offsetDelta * @param k the <cod>k</code> last locals are absent. */ - public void chopFrame(int pos, int offsetDelta, int k) {} + public void chopFrame(int pos, int offsetDelta, int k) throws BadBytecode {} - private int appendFrame(int pos, int type) { + private int appendFrame(int pos, int type) throws BadBytecode { int k = type - 251; int offset = ByteArray.readU16bit(info, pos + 1); int[] tags = new int[k]; @@ -290,9 +301,10 @@ public class StackMapTable extends AttributeInfo { * @param data <code>locals[i].cpool_index</code> * or <cod>locals[i].offset</code>. */ - public void appendFrame(int pos, int offsetDelta, int[] tags, int[] data) {} + public void appendFrame(int pos, int offsetDelta, int[] tags, int[] data) + throws BadBytecode {} - private int fullFrame(int pos) { + private int fullFrame(int pos) throws BadBytecode { int offset = ByteArray.readU16bit(info, pos + 1); int numOfLocals = ByteArray.readU16bit(info, pos + 3); int[] localsTags = new int[numOfLocals]; @@ -319,7 +331,8 @@ public class StackMapTable extends AttributeInfo { * or <code>stack[i].offset</code> */ public void fullFrame(int pos, int offsetDelta, int[] localTags, int[] localData, - int[] stackTags, int[] stackData) {} + int[] stackTags, int[] stackData) + throws BadBytecode {} private int verifyTypeInfo(int pos, int n, int[] tags, int[] data) { for (int i = 0; i < n; i++) { @@ -335,15 +348,12 @@ public class StackMapTable extends AttributeInfo { } } - static class Copier extends Walker { + static class SimpleCopy extends Walker { private Writer writer; - private ConstPool srcPool, destPool; - public Copier(ConstPool src, byte[] data, ConstPool dest) { + public SimpleCopy(byte[] data) { super(data); writer = new Writer(data.length); - srcPool = src; - destPool = dest; } public byte[] doit() throws BadBytecode { @@ -356,10 +366,7 @@ public class StackMapTable extends AttributeInfo { } public void sameLocals(int pos, int offsetDelta, int stackTag, int stackData) { - if (stackTag == OBJECT) - stackData = srcPool.copy(stackData, destPool, null); - - writer.sameLocals(offsetDelta, stackTag, stackData); + writer.sameLocals(offsetDelta, stackTag, copyData(stackTag, stackData)); } public void chopFrame(int pos, int offsetDelta, int k) { @@ -376,7 +383,32 @@ public class StackMapTable extends AttributeInfo { stackTags, copyData(stackTags, stackData)); } - private int[] copyData(int[] tags, int[] data) { + protected int copyData(int tag, int data) { + return data; + } + + protected int[] copyData(int[] tags, int[] data) { + return data; + } + } + + static class Copier extends SimpleCopy { + private ConstPool srcPool, destPool; + + public Copier(ConstPool src, byte[] data, ConstPool dest) { + super(data); + srcPool = src; + destPool = dest; + } + + protected int copyData(int tag, int data) { + if (tag == OBJECT) + return srcPool.copy(data, destPool, null); + else + return data; + } + + protected int[] copyData(int[] tags, int[] data) { int[] newData = new int[data.length]; for (int i = 0; i < data.length; i++) if (tags[i] == OBJECT) @@ -391,23 +423,11 @@ public class StackMapTable extends AttributeInfo { /** * A writer of stack map tables. */ - static class Writer { + public static class Writer { ByteArrayOutputStream output; int numOfEntries; /** - * Prints the stack table map. - */ - public static void print(StackMapTable smt, PrintWriter writer) { - try { - new Printer(smt.get(), writer).parse(); - } - catch (BadBytecode e) { - writer.println(e.getMessage()); - } - } - - /** * Constructs a writer. * @param size the initial buffer size. */ @@ -522,6 +542,7 @@ public class StackMapTable extends AttributeInfo { writeTypeInfo(localTags[i], localData[i]); n = stackTags.length; + write16(n); for (int i = 0; i < n; i++) writeTypeInfo(stackTags[i], stackData[i]); } @@ -541,6 +562,18 @@ public class StackMapTable extends AttributeInfo { static class Printer extends Walker { private PrintWriter writer; + /** + * Prints the stack table map. + */ + public static void print(StackMapTable smt, PrintWriter writer) { + try { + new Printer(smt.get(), writer).parse(); + } + catch (BadBytecode e) { + writer.println(e.getMessage()); + } + } + Printer(byte[] data, PrintWriter pw) { super(data); writer = pw; @@ -612,4 +645,166 @@ public class StackMapTable extends AttributeInfo { writer.println(msg); } } + + void shiftPc(int where, int gapSize, boolean exclusive) + throws BadBytecode + { + new Shifter(this, where, gapSize, exclusive).doit(); + } + + static class Shifter extends Walker { + private StackMapTable stackMap; + private int where, gap; + private int position; + private byte[] updatedInfo; + private boolean exclusive; + + public Shifter(StackMapTable smt, int where, int gap, boolean exclusive) { + super(smt); + stackMap = smt; + this.where = where; + this.gap = gap; + this.position = 0; + this.updatedInfo = null; + this.exclusive = exclusive; + } + + public void doit() throws BadBytecode { + parse(); + if (updatedInfo != null) + stackMap.set(updatedInfo); + } + + public void sameFrame(int pos, int offsetDelta) { + update(pos, offsetDelta, 0, 251); + } + + public void sameLocals(int pos, int offsetDelta, int stackTag, int stackData) { + update(pos, offsetDelta, 64, 247); + } + + private void update(int pos, int offsetDelta, int base, int entry) { + int oldPos = position; + position = oldPos + offsetDelta + (oldPos == 0 ? 0 : 1); + boolean match; + if (exclusive) + match = oldPos < where && where <= position; + else + match = oldPos <= where && where < position; + + if (match) { + int newDelta = offsetDelta + gap; + position += gap; + if (newDelta < 64) + info[pos] = (byte)(newDelta + base); + else if (offsetDelta < 64) { + byte[] newinfo = insertGap(info, pos, 2); + newinfo[pos] = (byte)entry; + ByteArray.write16bit(newDelta, info, pos + 1); + updatedInfo = newinfo; + } + else + ByteArray.write16bit(newDelta, info, pos + 1); + } + } + + private static byte[] insertGap(byte[] info, int where, int gap) { + int len = info.length; + byte[] newinfo = new byte[len + gap]; + for (int i = 0; i < len; i++) + newinfo[i + (i < where ? 0 : gap)] = info[i]; + + return newinfo; + } + + public void chopFrame(int pos, int offsetDelta, int k) { + update(pos, offsetDelta); + } + + public void appendFrame(int pos, int offsetDelta, int[] tags, int[] data) { + update(pos, offsetDelta); + } + + public void fullFrame(int pos, int offsetDelta, int[] localTags, int[] localData, + int[] stackTags, int[] stackData) { + update(pos, offsetDelta); + } + + private void update(int pos, int offsetDelta) { + int oldPos = position; + position = oldPos + offsetDelta + (oldPos == 0 ? 0 : 1); + boolean match; + if (exclusive) + match = oldPos < where && where <= position; + else + match = oldPos <= where && where < position; + + if (match) { + int newDelta = offsetDelta + gap; + ByteArray.write16bit(newDelta, info, pos + 1); + position += gap; + } + } + } + + /** + * Undocumented method. Do not use; internal-use only. + * + * <p>This method is for javassist.convert.TransformNew. + * It is called to update the stack map table when + * the NEW opcode (and the following DUP) is removed. + * + * @param where the position of the removed NEW opcode. + */ + public void removeNew(int where) throws CannotCompileException { + try { + byte[] data = new NewRemover(this.get(), where).doit(); + this.set(data); + } + catch (BadBytecode e) { + throw new CannotCompileException("bad stack map table", e); + } + } + + static class NewRemover extends SimpleCopy { + int posOfNew; + + public NewRemover(byte[] data, int pos) { + super(data); + posOfNew = pos; + } + + public void sameLocals(int pos, int offsetDelta, int stackTag, int stackData) { + if (stackTag == UNINIT && stackData == posOfNew) + super.sameFrame(pos, offsetDelta); + else + super.sameLocals(pos, offsetDelta, stackTag, stackData); + } + + public void fullFrame(int pos, int offsetDelta, int[] localTags, int[] localData, + int[] stackTags, int[] stackData) { + int n = stackTags.length - 1; + for (int i = 0; i < n; i++) + if (stackTags[i] == UNINIT && stackData[i] == posOfNew + && stackTags[i + 1] == UNINIT && stackData[i + 1] == posOfNew) { + n++; + int[] stackTags2 = new int[n - 2]; + int[] stackData2 = new int[n - 2]; + int k = 0; + for (int j = 0; j < n; j++) + if (j == i) + j++; + else { + stackTags2[k] = stackTags[j]; + stackData2[k++] = stackData[j]; + } + + stackTags = stackTags2; + stackData = stackData2; + break; + } + + super.fullFrame(pos, offsetDelta, localTags, localData, stackTags, stackData); + } + } } |