package org.ibex.classgen;
-public class Code {
- /**
- * This should actually be called "ValueProducer", but that
- * requires more typing.
- *
- * A Value is anything that generates an item on the stack.
- * Every instruction that causes something new to appear on the
- * stack implements Value. Every instruction that uses
- * something(s) on the stack will hold a reference to the thing
- * (almost always an instruction) that generates the thing(s) it
- * removes from the stack.
- */
- public interface Value {
- // commented out so that the rest of this file compiles
- // Instruction[] getUsers();
+/**
+ * a highly streamlined SSA-form intermediate representation of a
+ * sequence of JVM instructions; all stack manipulation is factored
+ * out.
+ */
+public class JSSA {
+
+ // Constructor //////////////////////////////////////////////////////////////////////////////
+
+ public JSSA(MethodGen mg) {
+ Expr[] reg = new Expr[5];
+ for(int i=0; i<mg.size(); i++) {
+ int op = mg.get(i);
+ Object arg = mg.getArg(i);
+ addOp(mg, op, arg);
+ }
+ }
+
+ // Instance Data; used ONLY during constructor; then thrown away /////////////////////////////////////////////////
+
+ /** this models the JVM registers; it is only used for unwinding stack-ops into an SSA-tree, then thrown away */
+ private Expr[] reg = new Expr[5];
+
+ /** this models the JVM stack; it is only used for unwinding stack-ops into an SSA-tree, then thrown away */
+ private Expr[] stack = new Expr[65535];
+
+ /** JVM stack pointer */
+ private int sp = 0;
+
+ private Expr push(Expr e) { return stack[sp++] = e; }
+ private Expr pop() { return stack[--sp]; }
+
+
+ // SSA-node classes /////////////////////////////////////////////////////////////////////////////////////////
+
+ /** an purely imperative operation which does not generate data */
+ public abstract class Op {
+ //public abstract Op[] predecessors(); // not implemented yet
+ //public abstract Op[] successors(); // not implemented yet
+ }
+
+ /** an operation which generates data */
+ public abstract class Expr extends Op {
+ //public abstract Expr[] contributors(); // not implemented yet
+ //public abstract Expr[] dependents(); // not implemented yet
+
+ /** every JSSA.Expr either remembers its type _OR_ knows how to figure it out (the latter is preferred to eliminate
+ * redundant information that could possibly "disagree" with itself -- this happened a LOT in Soot) */
+ public abstract Type getType();
}
/**
- * A "nondeterministic box" -- for example when the first
- * instruction in a loop reads from a local which could have been
- * written to either by some instruction at the end of the
- * previous iteration of the loop or by some instruction before
+ * A "nondeterministic merge" -- for example when the first instruction in a loop reads from a local which could have been
+ * written to either by some instruction at the end of the previous iteration of the loop or by some instruction before
* the loop (on the first iteration).
*/
- public class Phi implements Value {
- public Phi(Value[] inputs) { }
- public Instruction[] getUsers() { return null; /* FIXME */ }
+ public class Phi extends Expr {
+ private final Expr[] inputs;
+ public Phi(Expr[] inputs) {
+ this.inputs = new Expr[inputs.length];
+ System.arraycopy(inputs, 0, this.inputs, 0, inputs.length);
+ }
+ public Type getType() {
+ // sanity check
+ Type t = inputs[0].getType();
+
+ // FIXME: actually this should check type-unifiability... fe, the "type of null" unifies with any Type.Ref
+ for(int i=1; i<inputs.length; i++)
+ if (inputs[i].getType() != t)
+ throw new Error("Phi node with disagreeing types! Crisis!");
+ }
}
- /** any instruction which does not -- by itself -- remove anything from the stack */
- public class Instruction { }
- /** any instruction that consumes one item from the stack */
- public class OneOp extends Instruction { Value in; }
+public class Cast extends Expr {
+ final Expr e;
+ final Type t;
+ public Cast(Expr e, Type t) { this.e = e; this.t = t; }
+ public Type getType() { return t; }
+}
- /** any instruction that consumes two items from the stack */
- public class TwoOp extends Instruction { Value in1, in2; }
-
- /** a sequence of instructions */
- public class Sequence extends Instruction { Instruction[] code; }
- public class Monitor extends Sequence { Value objectToSynchronizeOn; }
- public class TryCatchFinally extends Sequence { OneOp[] catchBodies; Instruction finallyBody; }
-
- public class Goto extends Instruction { Instruction target; }
- public class JSR extends Instruction implements Value { Instruction target; }
- public class Ret extends OneOp { }
- public class Nop extends Instruction { }
-
- public class Constant extends Instruction implements Value { /** ??? **/ }
- public class LDC extends Instruction implements Value { Type.Class klass; }
- public class New extends Instruction implements Value { Type.Ref type; }
- public class ArrayLength extends OneOp implements Value { }
- public class ArrayIndex extends Instruction implements Value { }
- public class Return extends OneOp { }
- public class ReturnVoid extends Instruction { }
- public class CheckCast extends OneOp implements Value { Type.Ref castTarget; }
- public class Instanceof extends OneOp implements Value { Type.Class klass; }
- public class If extends OneOp { Instruction thenTarget, elseTarget; }
- public class Switch extends OneOp {
- public class Table extends Switch { }
- public class Lookup extends Switch { }
+public class InstanceOf extends Expr {
+ final Expr e;
+ final Type t;
+ public InstanceOf(Expr e, Type t) { this.e = e; this.t = t; }
+ public Type getType() { return Type.BOOLEAN; }
+}
+
+public class Branch extends Op {
+ public class Goto extends Branch { }
+ public class GoSub extends Branch { }
+ public class Ret extends Branch { }
+ public class If extends Branch { }
+}
+
+/** represents a "returnaddr" pushed onto the stack */
+public class Label extends Expr {
+ public final Op op;
+ public Type getType() { throw new Error("attempted to call getType() on a Label"); }
+ public Label(Op op) { this.op = op; }
+}
+
+public class Allocate extends Expr {
+ public final Type t;
+ public Type getType() { return t; }
+ public Allocate(Type t) { this.t = t; }
+}
+
+public class Return extends Op {
+ final Expr e;
+ public Return() { this(null); }
+ public Return(Expr e) { this.e = e; }
+}
+
+/** GETFIELD and GETSTATIC */
+public class Get extends Expr {
+ final Type.Class.Field f;
+ final Expr e;
+ public Type getType() { return f.getType(); }
+ public Get(Field f) { this(f, null); }
+ public Get(Field f, Expr e) { this.f = f; this.e = e; }
+}
+
+/** PUTFIELD and PUTSTATIC */
+public class Put extends Op {
+ final Type.Class.Field f;
+ final Expr v;
+ final Expr e;
+ public Put(Field f, Expr v) { this(f, v, null); }
+ public Put(Field f, Expr v, Expr e) { this.f = f; this.v = v; this.e = e; }
+}
+
+public class ArrayPut extends Op {
+ final Expr e, i, v;
+ public ArrayPut(Expr e, Expr i, Expr v) { this.e = e; this.i = i; this.v = v; }
+}
+
+public class ArrayGet extends Expr {
+ final Expr e, i;
+ public ArrayGet(Expr e, Expr i) { this.e = e; this.i = i; this.v = v; }
+ public Type getType() { return e.getType().asArray().elementType(); }
+}
+
+public class ArrayLength extends Expr {
+ final Expr e;
+ public ArrayLength(Expr e) { this.e = e; }
+ public Type getType() { return Type.INTEGER; }
+}
+
+public abstract class Invoke extends Op {
+ public final Expr[] arguments;
+ public final Type.Class.Method method;
+ protected Invoke(Type.Class.Method m, Expr[] a) { this.arguments = a; this.method m; }
+
+ public Type getType() { return method.getReturnType(); }
+
+ public class Static extends Invoke { public Static(Type.Class.Method m, Expr[] a) { super(m,a); } }
+ public class Special extends Virtual { public Special(Type.Class.Method m, Expr[] a, Expr e) { super(m,a,e); } }
+ public class Interface extends Virtual { public Virtual(Type.Class.Method m, Expr[] a, Expr e) { super(m,a,e); } }
+ public class Virtual extends Invoke {
+ public final Expr instance;
+ public Virtual(Type.Class.Method m, Expr[] a, Expr e) { super(m, a); instance = e; }
+ }
+}
+
+public static class Constant extends Expr {
+ private final Object o;
+ public Constant(Object o) { this.o = o; }
+ public Type getType() {
+ if (o instanceof Byte) return Type.BYTE;
+ if (o instanceof Short) return Type.SHORT;
+ if (o instanceof Char) return Type.CHAR;
+ if (o instanceof Boolean) return Type.BOOLEAN;
+ if (o instanceof Long) return Type.LONG;
+ if (o instanceof Double) return Type.DOUBLE;
+ if (o instanceof Float) return Type.FLOAT;
+ if (o instanceof ConstantPool.Ent) throw new Error("unimplemented");
+ throw new Error("this should not happen");
}
+}
+
+ // Implementation //////////////////////////////////////////////////////////////////////////////
+
+ private void addOp(MethodGen mg, int op, Object arg) {
+ Number number = null;
+ int i1 = 0;
+ int i2 = 0;
+ if (op==WIDE) {
+ Wide w = (Wide)arg;
+ op = w.op;
+ arg = null;
+ i1 = w.varNum;
+ i2 = w.n;
+ }
+ if (op==IINC) {
+ Pair p = (Pair)arg;
+ arg = null;
+ i1 = p.i1;
+ i2 = p.i2;
+ }
+ if (arg != null && arg instanceof Number) number = (Number)arg;
+ switch(op) {
+
+ case NOP: return null;
+
+ // Stack manipulations //////////////////////////////////////////////////////////////////////////////
+
+ case ACONST_NULL: return stack[sp++] = new Constant(null);
+ case ICONST_M1: return stack[sp++] = new Constant(-1);
+ case ICONST_0: case LCONST_0: case FCONST_0: case DCONST_0: return reg[0] = new Constant(i1);
+ case ICONST_1: case LCONST_1: case FCONST_1: case DCONST_1: return reg[1] = new Constant(i1);
+ case ICONST_2: case FCONST_2: return reg[2] = new Constant(i1);
+ case ICONST_3: return reg[3] = new Constant(i1);
+ case ICONST_4: return reg[4] = new Constant(i1);
+ case ICONST_5: return reg[5] = new Constant(i1);
+ case ILOAD: case LLOAD: case FLOAD: case DLOAD: case ALOAD: return stack[sp++] = reg[i1];
+ case ILOAD_0: case LLOAD_0: case FLOAD_0: case DLOAD_0: case ALOAD_0: return stack[sp++] = reg[0];
+ case ILOAD_1: case LLOAD_1: case FLOAD_1: case DLOAD_1: case ALOAD_1: return stack[sp++] = reg[1];
+ case ALOAD_2: case DLOAD_2: case FLOAD_2: case LLOAD_2: case ILOAD_2: return stack[sp++] = reg[2];
+ case ILOAD_3: case LLOAD_3: case FLOAD_3: case DLOAD_3: case ALOAD_3: return stack[sp++] = reg[3];
+ case ISTORE: case LSTORE: case FSTORE: case DSTORE: case ASTORE: return reg[i1] = stack[sp++];
+ case ISTORE_0: case LSTORE_0: case FSTORE_0: case DSTORE_0: case ASTORE_0: return reg[0] = stack[sp++];
+ case ISTORE_1: case LSTORE_1: case FSTORE_1: case DSTORE_1: case ASTORE_1: return reg[1] = stack[sp++];
+ case ASTORE_2: case DSTORE_2: case FSTORE_2: case LSTORE_2: case ISTORE_2: return reg[2] = stack[sp++];
+ case ISTORE_3: case LSTORE_3: case FSTORE_3: case DSTORE_3: case ASTORE_3: return reg[3] = stack[sp++];
+ case POP: stack[--sp] = null;
+ case POP2: stack[--sp] = null; stack[--sp] = null; /** fixme: pops a WORD, not an item */
+ case DUP: stack[sp] = stack[sp-1]; sp++;
+ case DUP2: stack[sp] = stack[sp-2]; stack[sp+1] = stack[sp-1]; sp+=2;
+
+ // Conversions //////////////////////////////////////////////////////////////////////////////
+
+ // coercions are added as-needed when converting from JSSA back to bytecode, so we can
+ // simply discard them here (assuming the bytecode we're reading in was valid in the first place)
+
+ case I2L: case F2L: case D2L: return push(new Cast(pop(), Type.LONG));
+ case I2F: case L2F: case D2F: return push(new Cast(pop(), Type.FLOAT));
+ case I2D: case L2D: case F2D: return push(new Cast(pop(), Type.DOUBLE));
+ case L2I: case F2I: case D2I: return push(new Cast(pop(), Type.INT));
+ case I2B: return push(new Cast(pop(), Type.BYTE));
+ case I2C: return push(new Cast(pop(), Type.CHAR));
+ case I2S: return push(new Cast(pop(), Type.SHORT));
+ case SWAP: { Expr e1 = pop(), e2 = pop(); return push(e2); return push(e1); }
+
+ // Math //////////////////////////////////////////////////////////////////////////////
+
+ case IADD: case LADD: case FADD: case DADD: return push(new Add(pop(), pop()));
+ case ISUB: case LSUB: case FSUB: case DSUB: return push(new Sub(pop(), pop()));
+ case IMUL: case LMUL: case FMUL: case DMUL: return push(new Mul(pop(), pop()));
+ case IREM: case LREM: case FREM: case DREM: return push(new Rem(pop(), pop()));
+ case INEG: case LNEG: case FNEG: case DNEG: return push(new Neg(pop(), pop()));
+ case IDIV: case LDIV: case FDIV: case DDIV: return push(new Div(pop(), pop()));
+ case ISHL: case LSHL: return push(new Shl(pop(), pop()));
+ case ISHR: case LSHR: return push(new Shr(pop(), pop()));
+ case IUSHR: case LUSHR: return push(new Ushr(pop(), pop()));
+ case IAND: case LAND: return push(new And(pop(), pop()));
+ case IOR: case LOR: return push(new Or(pop(), pop()));
+ case IXOR: case LXOR: return push(new Xor(pop(), pop()));
+ case IINC: return reg[i1] = new Add(reg[i1], new Constant(i2));
+
+ // Control and branching //////////////////////////////////////////////////////////////////////////////
+
+ case IFNULL: return new Branch(eq(pop(), new Constant(null)), new Label(arg));
+ case IFNONNULL: return new Branch(not(eq(pop(), new Constant(null))), new Label(arg));
+ case IFEQ: return new Branch( eq(new Constant(0), pop()), arg);
+ case IFNE: return new Branch(not(eq(new Constant(0), pop())), arg);
+ case IFLT: return new Branch( lt(new Constant(0), pop()), arg);
+ case IFGE: return new Branch(not(lt(new Constant(0), pop())), arg);
+ case IFGT: return new Branch( gt(new Constant(0), pop()), arg);
+ case IFLE: return new Branch(not(gt(new Constant(0), pop())), arg);
+ case IF_ICMPEQ: return new Branch( eq(pop(), pop()), arg);
+ case IF_ICMPNE: return new Branch(not(eq(pop(), pop())), arg);
+ case IF_ICMPLT: return new Branch( lt(pop(), pop()), arg);
+ case IF_ICMPGE: return new Branch(not(lt(pop(), pop())), arg);
+ case IF_ICMPGT: return new Branch( gt(pop(), pop()), arg);
+ case IF_ICMPLE: return new Branch(not(gt(pop(), pop())), arg);
+ case IF_ACMPEQ: return new Branch( eq(pop(), pop()), arg);
+ case IF_ACMPNE: return new Branch(not(eq(pop(), pop())), arg);
+ case ATHROW: return new Throw(pop());
+ case GOTO: return new Branch(new Label(arg));
+ case JSR: return new Branch.JSR(new Label(arg));
+ case RET: return new Branch.RET();
+ case RETURN: return new Return();
+ case IRETURN: case LRETURN: case FRETURN: case DRETURN: case ARETURN:
+ return new Return(pop());
+
+ // Array manipulations //////////////////////////////////////////////////////////////////////////////
+
+ case IALOAD: case LALOAD: case FALOAD: case DALOAD: case AALOAD:
+ case BALOAD: case CALOAD: case SALOAD: return push(new ArrayGet(pop(), pop()));
+ case IASTORE: case LASTORE: case FASTORE: case DASTORE: case AASTORE:
+ case BASTORE: case CASTORE: case SASTORE: return new ArrayPut(pop(), pop(), pop());
+
+ // Invocation //////////////////////////////////////////////////////////////////////////////
+
+ case INVOKEVIRTUAL: case INVOKESPECIAL: case INVOKESTATIC: case INVOKEINTERFACE: {
+ Type.Class.Method method = (Type.Class.Method)arg;
+ Expr args[] = new Expr[method.getNumArgs()];
+ for(int i=0; i<args.length; i++) args[args.length-i] = pop();
+ switch(op) {
+ case INVOKEVIRTUAL: return push(new Invoke.Virtual(method, args), pop());
+ case INVOKEINTERFACE: return push(new Invoke.Interface(method, args), pop());
+ case INVOKESPECIAL: return push(new Invoke.Special(method, args), pop());
+ case INVOKESTATIC: return push(new Invoke.Static(method, args));
+ }
+ }
+
+ // Field Access //////////////////////////////////////////////////////////////////////////////
+
+ case GETSTATIC: return push(new Get((Type.Class.Field)arg, null));
+ case PUTSTATIC: new Put((Type.Class.Field)arg, pop(), null);
+ case GETFIELD: return push(new Get((Type.Class.Field)arg, pop()));
+ case PUTFIELD: new Put((Type.Class.Field)arg, pop(), pop());
+
+ // Allocation //////////////////////////////////////////////////////////////////////////////
+
+ case NEW:
+ case NEWARRAY: return push(new Allocate((Type)arg, pop()));
+ case ANEWARRAY: return push(new Allocate(Type.OBJECT.makeArray(), pop()));
+ case MULTIANEWARRAY: return push(new Allocate(Type.OBJECT.makeArray(i2), /* FIXME */));
+ case ARRAYLENGTH: return push(new ArrayLength(pop()));
+
+ // Runtime Type information //////////////////////////////////////////////////////////////////////////////
+
+ case CHECKCAST: return push(new Cast(pop(), (Type)arg));
+ case INSTANCEOF: return push(new InstanceOf(pop(), (Type)arg));
+
+ case LDC: case LDC_W: case LDC2_W: return push(new Constant(arg));
+
+ case BIPUSH: return push(new Constant(i1)); // FIXME
+ case SIPUSH: return push(new Constant(i1)); // FIXME
+
+ case TABLESWITCH: new Branch((MethodGen.Switch)arg);
+ case LOOKUPSWITCH: new Branch((MethodGen.Switch)arg);
+
+ case MONITORENTER: Op.monitorEnter(pop());
+ case MONITOREXIT: Op.monitorExit(pop());
- public abstract class Invoke extends Instruction {
- Value[] arguments;
- Type.Class.Method method;
- public class Static extends Invoke implements Value { }
- public class Special extends Invoke implements Value { }
- public class Virtual extends Invoke implements Value { Value instance; }
+ case DUP_X1: throw new Error("unimplemented");
+ case DUP_X2: throw new Error("unimplemented");
+ case DUP2_X1: throw new Error("unimplemented");
+ case DUP2_X2: throw new Error("unimplemented");
+ case LCMP: throw new Error("unimplemented");
+ case FCMPL: throw new Error("unimplemented");
+ case FCMPG: throw new Error("unimplemented");
+ case DCMPL: throw new Error("unimplemented");
+ case DCMPG: throw new Error("unimplemented");
+ case GOTO_W: throw new Error("unimplemented");
+ case JSR_W: throw new Error("unimplemented");
+ default: throw new Error("unhandled");
+ }
}
}
projects / org.ibex.classgen.git / commitdiff