X-Git-Url: http://git.megacz.com/?p=org.ibex.classgen.git;a=blobdiff_plain;f=src%2Forg%2Fibex%2Fclassgen%2FMethodGen.java;h=703ab970977b9e26638b15461d1d5d9bc3f03ea5;hp=de4196b265063be010b034a0b547e1c1ee379775;hb=161a72a3b197b7f1c84954475aac89a7b191745d;hpb=ccbd3a82b1af7e5079019320adee50c728a74af9
diff --git a/src/org/ibex/classgen/MethodGen.java b/src/org/ibex/classgen/MethodGen.java
index de4196b..703ab97 100644
--- a/src/org/ibex/classgen/MethodGen.java
+++ b/src/org/ibex/classgen/MethodGen.java
@@ -3,8 +3,13 @@ package org.ibex.classgen;
import java.io.*;
import java.util.*;
+/** A class representing a method in a generated classfile
+ @see ClassGen#addMethod */
public class MethodGen implements CGConst {
- private final static boolean EMIT_NOPS = true;
+ private final static boolean EMIT_NOPS = false;
+
+ private static final int NO_CODE = -1;
+ private static final int FINISHED = -2;
private final CPGen cp;
private final String name;
@@ -44,6 +49,7 @@ public class MethodGen implements CGConst {
maxLocals = Math.max(args.length + (flags&ACC_STATIC)==0 ? 1 : 0,4);
}
+ /** Returns the descriptor string for this method */
public String getDescriptor() { return MethodRef.getDescriptor(ret,args); }
private class ExnTableEnt {
@@ -61,21 +67,32 @@ public class MethodGen implements CGConst {
o.writeShort(pc[start]);
o.writeShort(end==pc.length ? endPC : pc[end]);
o.writeShort(pc[handler]);
- o.writeShort(typeEnt.getIndex());
+ o.writeShort(cp.getIndex(typeEnt));
}
}
- public final void addExceptionHandler(int startPC, int endPC, int handlerPC, Type.Object type) {
- exnTable.put(type, new ExnTableEnt(startPC,endPC,handlerPC,cp.add(type)));
+ /** Adds an exception handler for the range [start,end) pointing to handler
+ @param start The instruction to start at (inclusive)
+ @param end The instruction to end at (exclusive)
+ @param handler The instruction of the excepton handler
+ @param type The type of exception that is to be handled (MUST inherit from Throwable)
+ */
+ public final void addExceptionHandler(int start, int end, int handler, Type.Object type) {
+ exnTable.put(type, new ExnTableEnt(start,end,handler,cp.add(type)));
}
+ /** Adds a exception type that can be thrown from this method
+ NOTE: This isn't enforced by the JVM. This is for reference only. A method can throw exceptions not declared to be thrown
+ @param type The type of exception that can be thrown
+ */
public final void addThrow(Type.Object type) {
thrownExceptions.put(type,cp.add(type));
}
private final void grow() { if(size == capacity) grow(size+1); }
private final void grow(int newCap) {
- if(capacity == -1) throw new IllegalStateException("method can't have code");
+ if(capacity == NO_CODE) throw new IllegalStateException("method can't have code");
+ if(capacity == FINISHED) throw new IllegalStateException("method has been finished");
if(newCap <= capacity) return;
newCap = Math.max(newCap,capacity == 0 ? 256 : capacity*2);
@@ -89,9 +106,14 @@ public class MethodGen implements CGConst {
capacity = newCap;
}
+
+ /** Returns the size (in instructions) of this method
+ @return The size of the method (in instructions)
+ */
public final int size() { return size; }
// These two are optimized for speed, they don't call set() below
+ /** Add a bytecode (with no argument) to the method */
public final int add(byte op) {
int s = size;
if(s == capacity) grow();
@@ -99,22 +121,57 @@ public class MethodGen implements CGConst {
size++;
return s;
}
+ /** Set the bytecode at position pos to op */
public final void set(int pos, byte op) { this.op[pos] = op; }
+ /** Adds a bytecode, op, with argument arg to the method
+ @return The position of the new bytecode
+ */
public final int add(byte op, Object arg) { if(capacity == size) grow(); set(size,op,arg); return size++; }
+ /** Adds a bytecode with a boolean argument - equivalent to add(op,arg?1:0);
+ @return The position of the new bytecode
+ @see #add(byte,int)
+ */
public final int add(byte op, boolean arg) { if(capacity == size) grow(); set(size,op,arg); return size++; }
+ /** Adds a bytecode with an integer argument. This is equivalent to add(op,new Integer(arg)), but optimized to prevent the allocation when possible
+ @return The position of the new bytecode
+ @see #add(byte,Object)
+ */
public final int add(byte op, int arg) { if(capacity == size) grow(); set(size,op,arg); return size++; }
+ /** Gets the bytecode at position pos
+ @exception ArrayIndexOutOfBoundException if pos < 0 || pos >= size()
+ */
public final byte get(int pos) { return op[pos]; }
+
+ /** Gets the bytecode at position pos. NOTE: This isn't necessarily the same object that was set with add or set.
+ Arguments for instructions which access the constant pool (LDC, INVOKEVIRTUAL, etc) are converted to a more efficient
+ interal form when they are added. The value returned from this method for these instruction can be reused, but there
+ is no way to retrieve the original object
+ @exception ArrayIndexOutOfBoundException if pos < 0 || pos >= size()
+ */
public final Object getArg(int pos) { return arg[pos]; }
+ /** Sets the argument for pos to arg. This is equivalent to set(pos,op,new Integer(arg)), but optimized to prevent the allocation when possible.
+ @exception ArrayIndexOutOfBoundException if pos < 0 || pos >= size()
+ @see #setArg(int,Object) */
public final void setArg(int pos, int arg) { set(pos,op[pos],N(arg)); }
+ /** Sets the argument for pos to arg.
+ @exception ArrayIndexOutOfBoundException if pos < 0 || pos >= size()
+ */
public final void setArg(int pos, Object arg) { set(pos,op[pos],arg); }
-
- public final void set(int pos, byte op, boolean b) { set(pos,op,b?1:0); }
+ /** Sets the bytecode and argument at pos to op and arg respectivly.
+ This is equivalent to set(pos,op,arg?1:0)
+ @exception ArrayIndexOutOfBoundException if pos < 0 || pos >= size()
+ */
+ public final void set(int pos, byte op, boolean arg) { set(pos,op,arg?1:0); }
// This MUST handle x{LOAD,STORE} and LDC with an int arg WITHOUT falling back to set(int,byte,Object)
+ /** Sets the bytecode and argument at pos to op and n respectivly.
+ This is equivalent to set(pos,op, new Integer(n)), but optimized to prevent the allocation when possible.
+ @exception ArrayIndexOutOfBoundException if pos < 0 || pos >= size()
+ */
public final void set(int pos, byte op, int n) {
Object arg = null;
OUTER: switch(op) {
@@ -134,6 +191,7 @@ public class MethodGen implements CGConst {
break;
case ILOAD: case ISTORE: case LLOAD: case LSTORE: case FLOAD:
case FSTORE: case DLOAD: case DSTORE: case ALOAD: case ASTORE:
+ if(n >= maxLocals) maxLocals = n + 1;
if(n >= 0 && n <= 3) {
byte base = 0;
switch(op) {
@@ -150,7 +208,6 @@ public class MethodGen implements CGConst {
}
op = (byte)((base&0xff) + n);
} else {
- if(n >= maxLocals) maxLocals = n + 1;
arg = N(n);
}
break;
@@ -162,6 +219,9 @@ public class MethodGen implements CGConst {
this.arg[pos] = arg;
}
+ /** Sets the bytecode and argument at pos to op and arg respectivly.
+ @exception ArrayIndexOutOfBoundException if pos < 0 || pos >= size()
+ */
public final void set(int pos, byte op, Object arg) {
switch(op) {
case ILOAD: case ISTORE: case LLOAD: case LSTORE: case FLOAD:
@@ -195,7 +255,11 @@ public class MethodGen implements CGConst {
this.arg[pos] = arg;
}
- public static class SI {
+ /** This class represents the arguments to the TABLESWITH and LOOKUPSWITCH bytecodes
+ @see MethodGen.TSI
+ @see MethodGen.LSI
+ */
+ public static abstract class SI {
public final Object[] targets;
public Object defaultTarget;
@@ -207,13 +271,15 @@ public class MethodGen implements CGConst {
public int size() { return targets.length; }
public int getTarget(int pos) { return ((Integer)targets[pos]).intValue(); }
- public int getDefaultTarget() { return ((Integer)defaultTarget).intValue(); }
+ public int getDefaultTarget() { return ((Integer)defaultTarget).intValue(); }
+
+ abstract int length();
}
+ /** This class represents the arguments to the TABLESWITCH bytecode */
public static class TSI extends SI {
public final int lo;
public final int hi;
- public int defaultTarget = -1;
public TSI(int lo, int hi) {
super(hi-lo+1);
this.lo = lo;
@@ -221,8 +287,11 @@ public class MethodGen implements CGConst {
}
public void setTargetForVal(int val, Object o) { setTarget(val-lo,o); }
public void setTargetForVal(int val, int n) { setTarget(val-lo,n); }
+
+ int length() { return 12 + targets.length * 4; } // 4bytes/target, hi, lo, default
}
+ /** This class represents the arguments to the LOOKUPSWITCH bytecode */
public static class LSI extends SI {
public final int[] vals;
public LSI(int size) {
@@ -230,17 +299,35 @@ public class MethodGen implements CGConst {
this.vals = new int[size];
}
public final void setVal(int pos, int val) { vals[pos] = val; }
+
+ int length() { return 8 + targets.length * 8; } // key/val per target, default, count
}
+ /** This class represents the arguments to byecodes that take two integer arguments. */
public static class Pair {
public int i1;
public int i2;
public Pair(int i1, int i2) { this.i1 = i1; this.i2 = i2; }
}
+
+ public static class Wide {
+ public final byte op;
+ public final int varNum;
+ public final int n;
+ Wide(byte op, int varNum) { this(op,varNum,0); }
+ Wide(byte op, int varNum, int n) { this.op = op; this.varNum = varNum; this.n = n; }
+ }
+ /** Sets the maximum number of locals in the function to maxLocals. NOTE: This defaults to 0 and is automatically increased as
+ necessary when *LOAD/*STORE bytecodes are added. You do not need to call this function in most cases */
public void setMaxLocals(int maxLocals) { this.maxLocals = maxLocals; }
+ /** Sets the maxinum size of th stack for this function to maxStack. This defaults to 16< */
public void setMaxStack(int maxStack) { this.maxStack = maxStack; }
+ /** Computes the final bytecode for this method.
+ @exception IllegalStateException if the data for a method is in an inconsistent state (required arguments missing, etc)
+ @exception Exn if the byteocode could not be generated for any other reason (constant pool full, etc)
+ */
public void finish() {
try {
_finish();
@@ -264,7 +351,9 @@ public class MethodGen implements CGConst {
}
private void _finish() throws IOException {
- if(size == -1) return;
+ if(size == FINISHED) return;
+
+ cp.stable();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
DataOutput o = new DataOutputStream(baos);
@@ -290,39 +379,59 @@ public class MethodGen implements CGConst {
}
switch(op) {
+ // Speical caculations
case GOTO:
- case JSR:
- p += 3;
- break;
+ case JSR: {
+ int arg = ((Integer)this.arg[i]).intValue();
+ if(arg < i && p - maxpc[arg] <= 32768) p += 3;
+ else p += 5;
+ continue;
+ }
case NOP:
if(EMIT_NOPS) p++;
- break;
+ continue;
case LOOKUPSWITCH:
case TABLESWITCH: {
SI si = (SI) arg[i];
Object[] targets = si.targets;
for(j=0;j 255) {
+ this.op[i] = WIDE;
+ this.arg[i] = new Wide(op,arg);
+ }
+ break;
+ }
+ case IINC: {
+ Pair pair = (Pair) this.arg[i];
+ if(pair.i1 > 255 || pair.i2 < -128 || pair.i2 > 127) {
+ this.op[i] = WIDE;
+ this.arg[i] = new Wide(IINC,pair.i1,pair.i2);
+ }
break;
}
case LDC:
- j = ((CPGen.Ent)arg[i]).getIndex();
+ j = cp.getIndex((CPGen.Ent)arg[i]);
if(j >= 256) this.op[i] = op = LDC_W;
- // fall through
- default:
- if((j = (opdata&OP_ARG_LENGTH_MASK)) == 7) throw new Error("shouldn't be here");
- p += 1 + j;
break;
+ default:
}
+ if((j = (opdata&OP_ARG_LENGTH_MASK)) == 7) throw new Error("shouldn't be here");
+ p += 1 + j;
}
// Pass2 - Widen instructions if they can possibly be too short
@@ -357,6 +466,9 @@ public class MethodGen implements CGConst {
else p += 4 + si.size() * 4 * 2; // count, key,val * targets
break;
}
+ case WIDE:
+ p += 2 + (((Wide)arg[i]).op == IINC ? 4 : 2);
+ break;
default: {
int l = OP_DATA[op&0xff] & OP_ARG_LENGTH_MASK;
if(l == 7) throw new Error("shouldn't be here");
@@ -364,9 +476,10 @@ public class MethodGen implements CGConst {
}
}
}
-
int codeSize = p;
+ if(codeSize >= 65536) throw new ClassGen.Exn("method too large in size");
+
o.writeShort(maxStack);
o.writeShort(maxLocals);
o.writeInt(codeSize);
@@ -376,8 +489,7 @@ public class MethodGen implements CGConst {
byte op = this.op[i];
int opdata = OP_DATA[op&0xff];
if(op == NOP && !EMIT_NOPS) continue;
-
- o.writeByte(op&0xff);
+ o.writeByte(op);
int argLength = opdata & OP_ARG_LENGTH_MASK;
if(argLength == 0) continue; // skip if no args
@@ -391,6 +503,7 @@ public class MethodGen implements CGConst {
if(pair.i1 > 255 || pair.i2 < -128 || pair.i2 > 127) throw new ClassGen.Exn("overflow of iinc arg");
o.writeByte(pair.i1);
o.writeByte(pair.i2);
+ break;
}
case TABLESWITCH:
case LOOKUPSWITCH: {
@@ -413,16 +526,27 @@ public class MethodGen implements CGConst {
}
break;
}
- case WIDE:
- throw new Error("WIDE instruction not yet supported");
+ case WIDE: {
+ Wide wide = (Wide) arg;
+ o.writeByte(wide.op);
+ o.writeShort(wide.varNum);
+ if(wide.op == IINC) o.writeShort(wide.n);
+ break;
+ }
default:
if((opdata & OP_BRANCH_FLAG) != 0) {
int v = pc[((Integer)arg).intValue()] - pc[i];
- if(v < -32768 || v > 32767) throw new ClassGen.Exn("overflow of s2 offset");
- o.writeShort(v);
+ if(argLength == 2) {
+ if(v < -32768 || v > 32767) throw new ClassGen.Exn("overflow of s2 offset");
+ o.writeShort(v);
+ } else if(argLength == 4) {
+ o.writeInt(v);
+ } else {
+ throw new Error("should never happen");
+ }
} else if((opdata & OP_CPENT_FLAG) != 0) {
- int v = ((CPGen.Ent)arg).getIndex();
+ int v = cp.getIndex((CPGen.Ent)arg);
if(argLength == 1) o.writeByte(v);
else if(argLength == 2) o.writeShort(v);
else throw new Error("should never happen");
@@ -434,7 +558,7 @@ public class MethodGen implements CGConst {
if(iarg < -128 || iarg >= 256) throw new ClassGen.Exn("overflow of s/u1 option");
o.writeByte(iarg);
} else if(argLength == 2) {
- if(iarg < -32767 || iarg >= 65536) throw new ClassGen.Exn("overflow of s/u2 option");
+ if(iarg < -32768 || iarg >= 65536) throw new ClassGen.Exn("overflow of s/u2 option");
o.writeShort(iarg);
} else {
throw new Error("should never happen");
@@ -461,13 +585,13 @@ public class MethodGen implements CGConst {
baos.reset();
o.writeShort(thrownExceptions.size());
for(Enumeration e = thrownExceptions.keys();e.hasMoreElements();)
- o.writeShort(((CPGen.Ent)thrownExceptions.get(e.nextElement())).getIndex());
+ o.writeShort(cp.getIndex((CPGen.Ent)thrownExceptions.get(e.nextElement())));
attrs.add("Exceptions",baos.toByteArray());
- size = -1;
+ size = capacity = FINISHED;
}
- public void dump(DataOutput o) throws IOException {
+ void dump(DataOutput o) throws IOException {
o.writeShort(flags);
o.writeShort(cp.getUtf8Index(name));
o.writeShort(cp.getUtf8Index(getDescriptor()));
@@ -475,6 +599,8 @@ public class MethodGen implements CGConst {
attrs.dump(o);
}
+ /** Negates the IF* instruction, op (IF_ICMPGT -> IF_ICMPLE, IFNE -> IFEQ, etc)
+ @exception IllegalArgumentException if op isn't an IF* instruction */
public static byte negate(byte op) {
switch(op) {
case IFEQ: return IFNE;
@@ -497,6 +623,8 @@ public class MethodGen implements CGConst {
}
}
+ /** Class that represents a target that isn't currently know. The target MUST be set with setTarget() before the classfile is written.
+ This class is more or less a mutable integer */
public static class PhantomTarget {
private int target = -1;
public void setTarget(int target) { this.target = target; }