public JSSA(Type.Class c, DataInput in, ConstantPool cp) throws IOException {
super(c, in, cp);
- local = new Expr[maxLocals];
- stack = new Expr[maxStack];
+ locals = new Phi[size()][maxLocals];
+ stacks = new Phi[size()][maxStack];
+ sps = new int [size()];
+ sps[0] = 0;
int n=0;
+ locals[0] = new Phi[maxLocals];
if (!isStatic())
- local[n++] = new Argument("this",method.getDeclaringClass());
+ locals[0][n++] = phi(new Argument("this",method.getDeclaringClass()));
for(int i=0;i<this.method.getNumArgs(); i++)
- local[n++] = new Argument("arg"+i, this.method.getArgType(i));
- for(int i=0; i<size(); i++) {
- int op = get(i);
- Object arg = getArg(i);
+ locals[0][n++] = phi(new Argument("arg"+i, this.method.getArgType(i)));
+ for(pc=0; pc<size(); pc++) {
+ int op = get(pc);
+ Object arg = getArg(pc);
try {
+ if (pc<size()-1) {
+ locals[pc+1] = new Phi[maxLocals];
+ for(int j=0; j<maxLocals; j++) locals[pc+1][j] = locals[pc][j];
+ sps[pc+1] = sps[pc];
+ stacks[pc+1] = new Phi[maxStack];
+ for(int j=0; j<sps[pc]; j++) stacks[pc+1][j] = stacks[pc][j];
+ }
Object o = addOp(op, arg);
if (o != null) {
ops[numOps] = o;
- ofs[numOps++] = i;
+ ofs[numOps++] = pc;
}
} catch(RuntimeException e) {
- System.err.println("Had a problem at PC: " + i + " of " + method);
+ System.err.println("Had a problem at PC: " + pc + " of " + method);
e.printStackTrace();
throw new IOException("invalid class file");
}
// Instance Data; used ONLY during constructor; then thrown away /////////////////////////////////////////////////
/** this models the JVM locals; it is only used for unwinding stack-ops into an SSA-tree, then thrown away */
- private final Expr[] local;
+ private final Phi[][] locals;
/** this models the JVM stack; it is only used for unwinding stack-ops into an SSA-tree, then thrown away */
- private final Expr[] stack;
+ private final Phi[][] stacks;
/** JVM stack pointer */
- private int sp = 0;
-
+ private final int sps[];
+ private int pc = 0;
+
private Expr push(Expr e) {
- if (sp == stack.length) {
- for(int i=0;i<stack.length;i++) System.err.println("Stack " + i + ": " + stack[i]);
- throw new IllegalStateException("stack overflow (" + stack.length + ")");
+ // FIXME: need to verify that stacks are same size at target of branch
+ if (sps[pc+1] == maxStack) {
+ for(int i=0;i<maxStack;i++) System.err.println("Stack " + i + ": " + stacks[pc][i]);
+ throw new IllegalStateException("stack overflow (" + maxStack + ")");
}
if (e.getType() == Type.VOID) throw new IllegalArgumentException("can't push a void");
- return stack[sp++] = e;
+ stacks[pc+1][sps[pc+1]++].merge(e);
+ return stacks[pc+1][sps[pc+1]++];
}
private Expr pop() {
- if (sp == 0) throw new IllegalStateException("stack underflow");
- return stack[--sp];
+ // FIXME: need to verify that stacks are same size at target of branch
+ if (pc == sps.length-1) { /* FIXME? */ return stacks[pc][sps[pc]-1]; }
+ if (sps[pc+1] == 0) throw new IllegalStateException("stack underflow");
+ sps[pc+1]--;
+ Expr ret = stacks[pc+1][sps[pc+1]];
+ stacks[pc+1][sps[pc+1]] = null;
+ return ret;
}
private Op seqPush(Expr e) {
/** 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();
-
- public final String toString() { return exprToString(this); }
- public String _toString() { return super.toString(); } // Adam is going to hate me for this (yes; why is this here?)
+ public String _toString() { return super.toString(); }
+ public String toString() {
+ String s = (String)bindingMap.get(this);
+ if (s != null) return s;
+ String prefix;
+ if (getType() == Type.VOID) return _toString();
+ else if (getType() == Type.DOUBLE || getType() == Type.FLOAT) prefix = "f";
+ else if (getType().isPrimitive()) prefix = "i";
+ else if (getType().isArray()) prefix = "a";
+ else prefix = "o";
+ s = prefix + (nextVar++);
+ bindingMap.put(this,s);
+ return "(" + s + " = " + _toString() + ")";
+ }
}
/**
- * 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
+ * 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).
+ *
+ * Note that Phi's are *mutable*. This means that when one Phi
+ * holds a reference to another, updates to the referenced Phi
+ * are "seen" by the other Phi. This prevents us from having to
+ * repeat loops to propagate the Phis.
*/
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);
+ Expr[] inputs;
+ public Phi(Expr[] inputs) { this.inputs = inputs; }
+ public Phi(Expr e1) {
+ this.inputs = new Expr[1];
+ inputs[0] = e1;
+ }
+ public Phi(Expr e1, Expr e2) {
+ this.inputs = new Expr[2];
+ inputs[0] = e1;
+ inputs[1] = e2;
+ }
+ public void merge(Expr e) {
+ Expr[] newinputs = new Expr[inputs.length + 1];
+ System.arraycopy(inputs, 0, newinputs, 0, inputs.length);
+ newinputs[newinputs.length-1] = e;
+ inputs = newinputs;
+ }
+ public String toString() {
+ if (inputs.length == 1) return inputs[0].toString();
+ StringBuffer ret = new StringBuffer();
+ ret.append("{{ ");
+ for(int i=0; i<inputs.length; i++) {
+ ret.append(inputs[i].toString());
+ ret.append(" ");
+ }
+ ret.append("}}");
+ return ret.toString();
}
public Type getType() {
// sanity check
}
}
+ public Phi phi(Expr e) { return e instanceof Phi ? ((Phi)e) : new Phi(e); }
+
public class Argument extends Expr {
public final String name;
public final Type t;
public Type getType() { return t; }
}
- // Unary Operations
+
+ // Unary Operations //////////////////////////////////////////////////////////////////////////////
+
public class Not extends Expr {
public final Expr e;
public Not(Expr e) {
public Type getType() { return e.getType(); }
public String _toString() { return "- (" + e + ")"; }
}
+
// Binary Operations //////////////////////////////////////////////////////////////////////////////
private final String show;
public BinExpr(Expr e1, Expr e2, String show) { this.e1 = e1; this.e2 = e2; this.show = show; }
public String _toString() {
- // FEATURE: should we be doing some precedence stuff here? probably no worth it for debugging output
+ // FEATURE: should we be doing some precedence stuff here? probably not worth it for debugging output
return "(" + e1 + show + e2 + ")";
}
}
public Eq(Expr e1, Expr e2) {
super(e1, e2, "==");
if (e1.getType().isPrimitive() != e2.getType().isPrimitive())
- throw new IllegalArgumentException("type mismatch");
+ throw new IllegalArgumentException("type mismatch: " + e1.getType() + " and " + e2.getType());
if (e1.getType().isPrimitive() && e1.getType() != e2.getType())
- throw new IllegalArgumentException("type mismatch");
+ throw new IllegalArgumentException("type mismatch: " + e1.getType() + " and " + e2.getType());
// FEATURE: Check if we can compare these classes
}
}
public class Lt extends PrimitiveComparison { public Lt(Expr e1, Expr e2) { super(e1, e2, "<"); } }
public class Ge extends PrimitiveComparison { public Ge(Expr e1, Expr e2) { super(e1, e2, ">="); } }
public class Le extends PrimitiveComparison { public Le(Expr e1, Expr e2) { super(e1, e2, "<="); } }
+
// Math Operations //////////////////////////////////////////////////////////////////////////////
private final Object o;
public Constant(int i) { this(new Integer(i)); }
public Constant(Object o) { this.o = o; }
- public String _toString() { return o == null ? "null" : o instanceof String ? "\"" + o + "\"" : o.toString(); }
+ public String toString() { return o == null ? "null" : o instanceof String ? "\"" + o + "\"" : o.toString(); }
public Type getType() {
if (o == null) return Type.NULL;
if (o instanceof Byte) return Type.BYTE;
case ICONST_3: push(new Constant(3)); return null;
case ICONST_4: push(new Constant(4)); return null;
case ICONST_5: push(new Constant(5)); return null;
- case ILOAD: case LLOAD: case FLOAD: case DLOAD: case ALOAD: push(local[i1]); return null;
- case ILOAD_0: case LLOAD_0: case FLOAD_0: case DLOAD_0: case ALOAD_0: push(local[0]); return null;
- case ILOAD_1: case LLOAD_1: case FLOAD_1: case DLOAD_1: case ALOAD_1: push(local[1]); return null;
- case ALOAD_2: case DLOAD_2: case FLOAD_2: case LLOAD_2: case ILOAD_2: push(local[2]); return null;
- case ILOAD_3: case LLOAD_3: case FLOAD_3: case DLOAD_3: case ALOAD_3: push(local[3]); return null;
- case ISTORE: case LSTORE: case FSTORE: case DSTORE: case ASTORE: local[i1] = pop(); return null;
- case ISTORE_0: case LSTORE_0: case FSTORE_0: case DSTORE_0: case ASTORE_0: local[0] = pop(); return null;
- case ISTORE_1: case LSTORE_1: case FSTORE_1: case DSTORE_1: case ASTORE_1: local[1] = pop(); return null;
- case ASTORE_2: case DSTORE_2: case FSTORE_2: case LSTORE_2: case ISTORE_2: local[2] = pop(); return null;
- case ISTORE_3: case LSTORE_3: case FSTORE_3: case DSTORE_3: case ASTORE_3: local[3] = pop(); return null;
+ case ILOAD: case LLOAD: case FLOAD: case DLOAD: case ALOAD: push(locals[pc][i1]); return null;
+ case ILOAD_0: case LLOAD_0: case FLOAD_0: case DLOAD_0: case ALOAD_0: push(locals[pc][0]); return null;
+ case ILOAD_1: case LLOAD_1: case FLOAD_1: case DLOAD_1: case ALOAD_1: push(locals[pc][1]); return null;
+ case ALOAD_2: case DLOAD_2: case FLOAD_2: case LLOAD_2: case ILOAD_2: push(locals[pc][2]); return null;
+ case ILOAD_3: case LLOAD_3: case FLOAD_3: case DLOAD_3: case ALOAD_3: push(locals[pc][3]); return null;
+ case ISTORE: case LSTORE: case FSTORE: case DSTORE: case ASTORE:
+ locals[pc+1][i1].merge(pop()); return null;
+ case ISTORE_0: case LSTORE_0: case FSTORE_0: case DSTORE_0: case ASTORE_0:
+ locals[pc+1][0].merge(pop()); return null;
+ case ISTORE_1: case LSTORE_1: case FSTORE_1: case DSTORE_1: case ASTORE_1:
+ locals[pc+1][1].merge(pop()); return null;
+ case ASTORE_2: case DSTORE_2: case FSTORE_2: case LSTORE_2: case ISTORE_2:
+ locals[pc+1][2].merge(pop()); return null;
+ case ISTORE_3: case LSTORE_3: case FSTORE_3: case DSTORE_3: case ASTORE_3:
+ locals[pc+1][3].merge(pop()); return null;
case POP: pop(); return null;
case POP2: pop(); pop(); return null;
- case DUP: push(stack[sp-1]); return null;
- case DUP2: push(stack[sp-2]); push(stack[sp-2]); return null;
+ case DUP: push(stacks[pc][sps[pc]-1]); return null;
+ case DUP2: push(stacks[pc][sps[pc]-2]); push(stacks[pc][sps[pc]-1]); return null;
// Conversions //////////////////////////////////////////////////////////////////////////////
case IAND: case LAND: push(new And(pop(), pop())); return null;
case IOR: case LOR: push(new Or(pop(), pop())); return null;
case IXOR: case LXOR: push(new Xor(pop(), pop())); return null;
- case IINC: return local[i1] = new Add(local[i1], new Constant(i2));
+ case IINC: return locals[pc+1][i1] = phi(new Add(locals[pc][i1], new Constant(i2)));
// Control and branching //////////////////////////////////////////////////////////////////////////////
private Map bindingMap;
private int nextVar;
- String exprToString(Expr e) {
- if (e instanceof Constant) return e._toString();
- String s = (String)bindingMap.get(e);
- if (s != null) return s;
- String prefix;
- if (e.getType() == Type.VOID) return e._toString();
- else if (e.getType() == Type.DOUBLE || e.getType() == Type.FLOAT) prefix = "f";
- else if (e.getType().isPrimitive()) prefix = "i";
- else if (e.getType().isArray()) prefix = "a";
- else prefix = "o";
- s = prefix + (nextVar++);
- bindingMap.put(e,s);
- return "(" + s + " = " + e._toString() + ")";
- }
public static void main(String[] args) throws Exception {
InputStream is = Class.forName(args[0]).getClassLoader().getResourceAsStream(args[0].replace('.', '/')+".class");
projects / org.ibex.classgen.git / commitdiff