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getStackPopPush

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git-svn-id: https://svn.code.sf.net/p/jode/code/trunk@820 379699f6-c40d-0410-875b-85095c16579e
stable
jochen 25 years ago
parent 9b316ad4c1
commit a4dc6e4427
1 changed files with 164 additions and 1 deletions
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  1. 165
      jode/jode/bytecode/Instruction.java

165
jode/jode/bytecode/Instruction.java
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@ -20,6 +20,8 @@
package jode.bytecode;
import java.util.Vector;
import java.util.Enumeration;
import jode.type.Type;
import jode.type.MethodType;
/**
* This class represents an instruction in the byte code.
@ -274,6 +276,105 @@ public class Instruction implements Opcodes{
}
}
/**
* This returns the number of stack entries this instruction
* pushes and pops from the stack. The result fills the given
* array.
*
* @param poppush an array of two ints. The first element will
* get the number of pops, the second the number of pushes.
*/
public void getStackPopPush(int[] poppush)
/*{ require { poppush != null && poppush.length == 2
:: "poppush must be an array of two ints" } } */
{
byte delta = stackDelta[opcode];
if (delta < 0x40) {
poppush[0] = delta & 7;
poppush[1] = delta >> 3;
} else {
switch (opcode) {
case opc_invokevirtual:
case opc_invokespecial:
case opc_invokestatic:
case opc_invokeinterface: {
Reference ref = (Reference) objData;
MethodType mt = (MethodType) Type.tType(ref.getType());
poppush[1] = mt.getReturnType().stackSize();
poppush[0] = opcode != opc_invokestatic ? 1 : 0;
for (int i = mt.getParameterTypes().length-1; i >= 0; i--)
poppush[0] += mt.getParameterTypes()[i].stackSize();
break;
}
case opc_putfield:
case opc_putstatic: {
Reference ref = (Reference) objData;
poppush[1] = 0;
poppush[0] = Type.tType(ref.getType()).stackSize();
if (opcode == opc_putfield)
poppush[0]++;
break;
}
case opc_getstatic:
case opc_getfield: {
Reference ref = (Reference) objData;
poppush[1] = Type.tType(ref.getType()).stackSize();
poppush[0] = opcode == opc_getfield ? 1 : 0;
break;
}
case opc_multianewarray: {
poppush[1] = 1;
poppush[0] = prevByAddr.intData;
break;
}
default:
throw new jode.AssertError("Unknown Opcode: "+opcode);
}
}
}
public Instruction findMatchingPop() {
int poppush[] = new int[2];
getStackPopPush(poppush);
int count = poppush[1];
Instruction instr = this;
while (true) {
if (instr.succs != null || instr.alwaysJumps)
return null;
instr = instr.nextByAddr;
if (instr.preds != null)
return null;
instr.getStackPopPush(poppush);
if (count == poppush[0])
return instr;
count += poppush[1] - poppush[0];
}
}
public Instruction findMatchingPush() {
int count = 0;
Instruction instr = this;
int poppush[] = new int[2];
while (true) {
if (instr.preds != null)
return null;
instr = instr.prevByAddr;
if (instr == null || instr.succs != null || instr.alwaysJumps)
return null;
instr.getStackPopPush(poppush);
if (count < poppush[1]) {
return count == 0 ? instr : null;
}
count += poppush[0] - poppush[1];
}
}
public String getDescription() {
StringBuffer result = new StringBuffer(String.valueOf(addr))
.append('_').append(Integer.toHexString(hashCode()))
@ -325,5 +426,67 @@ public class Instruction implements Opcodes{
public String toString() {
return ""+addr+"_"+Integer.toHexString(hashCode());
}
}
public final static byte[] stackDelta;
static {
stackDelta = new byte[202];
for (int i=0; i < 202; i++) {
stackDelta[i] = (byte) "\000\010\010\010\010\010\010\010\010\020\020\010\010\010\020\020\010\010\010\010\020\010\020\010\020\010\010\010\010\010\020\020\020\020\010\010\010\010\020\020\020\020\010\010\010\010\012\022\012\022\012\012\012\012\001\002\001\002\001\001\001\001\001\002\002\002\002\001\001\001\001\002\002\002\002\001\001\001\001\003\004\003\004\003\003\003\003\001\002\021\032\043\042\053\064\022\012\024\012\024\012\024\012\024\012\024\012\024\012\024\012\024\012\024\012\024\011\022\011\022\012\023\012\023\012\023\012\024\012\024\012\024\000\021\011\021\012\012\022\011\021\021\012\022\012\011\011\011\014\012\012\014\014\001\001\001\001\001\001\002\002\002\002\002\002\002\002\000\010\000\001\001\001\002\001\002\001\000\100\100\100\100\100\100\100\100\177\010\011\011\011\001\011\011\001\001\177\100\001\001\000\010".charAt(i);
}
}
/* stackDelta contains \100 if stack count of opcode is variable
* \177 if opcode is illegal, or 8*stack_push + stack_pop otherwise
* The above values are extracted from following list with:
* perl -ne'/"(.*)"/ and print $1'
*
* "\000" // nop
* "\010\010\010\010\010\010\010\010" // aconst_null, iconst_m?[0-5]
* "\020\020\010\010\010\020\020" // [lfd]const_[0-2]
* "\010\010\010\010\020" // sipush bipush ldcx
* "\010\020\010\020\010" // [ilfda]load
* "\010\010\010\010"
* "\020\020\020\020"
* "\010\010\010\010"
* "\020\020\020\020"
* "\010\010\010\010"
* "\012\022\012\022\012\012\012\012" // [ilfdabcs]aload
* "\001\002\001\002\001" // [ilfda]store
* "\001\001\001\001"
* "\002\002\002\002"
* "\001\001\001\001"
* "\002\002\002\002"
* "\001\001\001\001"
* "\003\004\003\004\003\003\003\003" // [ilfdabcs]astore
* "\001\002" // pop
* "\021\032\043\042\053\064" // dup2?(_x[12])?
* "\022" // swap
* "\012\024\012\024" // [ilfd]add
* "\012\024\012\024" // [ilfd]sub
* "\012\024\012\024" // [ilfd]mul
* "\012\024\012\024" // [ilfd]div
* "\012\024\012\024" // [ilfd]rem
* "\011\022\011\022" // [ilfd]neg
* "\012\023\012\023\012\023" // [il]u?sh[lr]
* "\012\024\012\024\012\024" // [il](and|or|xor)
* "\000" // opc_iinc
* "\021\011\021" // i2[lfd]
* "\012\012\022" // l2[ifd]
* "\011\021\021" // f2[ild]
* "\012\022\012" // d2[ilf]
* "\011\011\011" // i2[bcs]
* "\014\012\012\014\014" // [lfd]cmp.?
* "\001\001\001\001\001\001" // if..
* "\002\002\002\002\002\002" // if_icmp..
* "\002\002" // if_acmp..
* "\000\010\000\001\001" // goto,jsr,ret, .*switch
* "\001\002\001\002\001\000" // [ilfda]?return
* "\100\100\100\100" // (get/put)(static|field)
* "\100\100\100\100" // invoke.*
* "\177\010\011\011\011" // 186 - 190
* "\001\011\011\001\001" // 191 - 195
* "\177\100\001\001" // 196 - 199
* "\000\010" // goto_w, jsr_w
*/
}

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