/** * Replaces the given type with the appropriate type if it is one of the types on which a * constructor is invoked in the basic block. * * @param cw the ClassWriter to which this label belongs. * @param t a type * @return t or, if t is one of the types on which a constructor is invoked in the basic block, * the type corresponding to this constructor. */ private int init(final ClassWriter cw, final int t) { int s; if (t == UNINITIALIZED_THIS) { s = OBJECT | cw.addType(cw.thisName); } else if ((t & (DIM | BASE_KIND)) == UNINITIALIZED) { String type = cw.typeTable[t & BASE_VALUE].strVal1; s = OBJECT | cw.addType(type); } else { return t; } for (int j = 0; j < initializationCount; ++j) { int u = initializations[j]; int dim = u & DIM; int kind = u & KIND; if (kind == LOCAL) { u = dim + inputLocals[u & VALUE]; } else if (kind == STACK) { u = dim + inputStack[inputStack.length - (u & VALUE)]; } if (t == u) { return s; } } return t; }
/** * Merges the type at the given index in the given type array with the given type. Returns * <tt>true</tt> if the type array has been modified by this operation. * * @param cw the ClassWriter to which this label belongs. * @param t the type with which the type array element must be merged. * @param types an array of types. * @param index the index of the type that must be merged in 'types'. * @return <tt>true</tt> if the type array has been modified by this operation. */ private static boolean merge(final ClassWriter cw, int t, final int[] types, final int index) { int u = types[index]; if (u == t) { // if the types are equal, merge(u,t)=u, so there is no change return false; } if ((t & ~DIM) == NULL) { if (u == NULL) { return false; } t = NULL; } if (u == 0) { // if types[index] has never been assigned, merge(u,t)=t types[index] = t; return true; } int v; if ((u & BASE_KIND) == OBJECT || (u & DIM) != 0) { // if u is a reference type of any dimension if (t == NULL) { // if t is the NULL type, merge(u,t)=u, so there is no change return false; } else if ((t & (DIM | BASE_KIND)) == (u & (DIM | BASE_KIND))) { if ((u & BASE_KIND) == OBJECT) { // if t is also a reference type, and if u and t have the // same dimension merge(u,t) = dim(t) | common parent of the // element types of u and t v = (t & DIM) | OBJECT | cw.getMergedType(t & BASE_VALUE, u & BASE_VALUE); } else { // if u and t are array types, but not with the same element // type, merge(u,t)=java/lang/Object v = OBJECT | cw.addType("java/lang/Object"); } } else if ((t & BASE_KIND) == OBJECT || (t & DIM) != 0) { // if t is any other reference or array type, // merge(u,t)=java/lang/Object v = OBJECT | cw.addType("java/lang/Object"); } else { // if t is any other type, merge(u,t)=TOP v = TOP; } } else if (u == NULL) { // if u is the NULL type, merge(u,t)=t, // or TOP if t is not a reference type v = (t & BASE_KIND) == OBJECT || (t & DIM) != 0 ? t : TOP; } else { // if u is any other type, merge(u,t)=TOP whatever t v = TOP; } if (u != v) { types[index] = v; return true; } return false; }
/** * Initializes the input frame of the first basic block from the method descriptor. * * @param cw the ClassWriter to which this label belongs. * @param access the access flags of the method to which this label belongs. * @param args the formal parameter types of this method. * @param maxLocals the maximum number of local variables of this method. */ void initInputFrame( final ClassWriter cw, final int access, final Type[] args, final int maxLocals) { inputLocals = new int[maxLocals]; inputStack = new int[0]; int i = 0; if ((access & Opcodes.ACC_STATIC) == 0) { if ((access & MethodWriter.ACC_CONSTRUCTOR) == 0) { inputLocals[i++] = OBJECT | cw.addType(cw.thisName); } else { inputLocals[i++] = UNINITIALIZED_THIS; } } for (int j = 0; j < args.length; ++j) { int t = type(cw, args[j].getDescriptor()); inputLocals[i++] = t; if (t == LONG || t == DOUBLE) { inputLocals[i++] = TOP; } } while (i < maxLocals) { inputLocals[i++] = TOP; } }
/** * Simulates the action of the given instruction on the output stack frame. * * @param opcode the opcode of the instruction. * @param arg the operand of the instruction, if any. * @param cw the class writer to which this label belongs. * @param item the operand of the instructions, if any. */ void execute(final int opcode, final int arg, final ClassWriter cw, final Item item) { int t1, t2, t3, t4; switch (opcode) { case Opcodes.NOP: case Opcodes.INEG: case Opcodes.LNEG: case Opcodes.FNEG: case Opcodes.DNEG: case Opcodes.I2B: case Opcodes.I2C: case Opcodes.I2S: case Opcodes.GOTO: case Opcodes.RETURN: break; case Opcodes.ACONST_NULL: push(NULL); break; case Opcodes.ICONST_M1: case Opcodes.ICONST_0: case Opcodes.ICONST_1: case Opcodes.ICONST_2: case Opcodes.ICONST_3: case Opcodes.ICONST_4: case Opcodes.ICONST_5: case Opcodes.BIPUSH: case Opcodes.SIPUSH: case Opcodes.ILOAD: push(INTEGER); break; case Opcodes.LCONST_0: case Opcodes.LCONST_1: case Opcodes.LLOAD: push(LONG); push(TOP); break; case Opcodes.FCONST_0: case Opcodes.FCONST_1: case Opcodes.FCONST_2: case Opcodes.FLOAD: push(FLOAT); break; case Opcodes.DCONST_0: case Opcodes.DCONST_1: case Opcodes.DLOAD: push(DOUBLE); push(TOP); break; case Opcodes.LDC: switch (item.type) { case ClassWriter.INT: push(INTEGER); break; case ClassWriter.LONG: push(LONG); push(TOP); break; case ClassWriter.FLOAT: push(FLOAT); break; case ClassWriter.DOUBLE: push(DOUBLE); push(TOP); break; case ClassWriter.CLASS: push(OBJECT | cw.addType("java/lang/Class")); break; case ClassWriter.STR: push(OBJECT | cw.addType("java/lang/String")); break; case ClassWriter.MTYPE: push(OBJECT | cw.addType("java/lang/invoke/MethodType")); break; // case ClassWriter.MHANDLE_BASE + [1..9]: default: push(OBJECT | cw.addType("java/lang/invoke/MethodHandle")); } break; case Opcodes.ALOAD: push(get(arg)); break; case Opcodes.IALOAD: case Opcodes.BALOAD: case Opcodes.CALOAD: case Opcodes.SALOAD: pop(2); push(INTEGER); break; case Opcodes.LALOAD: case Opcodes.D2L: pop(2); push(LONG); push(TOP); break; case Opcodes.FALOAD: pop(2); push(FLOAT); break; case Opcodes.DALOAD: case Opcodes.L2D: pop(2); push(DOUBLE); push(TOP); break; case Opcodes.AALOAD: pop(1); t1 = pop(); push(ELEMENT_OF + t1); break; case Opcodes.ISTORE: case Opcodes.FSTORE: case Opcodes.ASTORE: t1 = pop(); set(arg, t1); if (arg > 0) { t2 = get(arg - 1); // if t2 is of kind STACK or LOCAL we cannot know its size! if (t2 == LONG || t2 == DOUBLE) { set(arg - 1, TOP); } else if ((t2 & KIND) != BASE) { set(arg - 1, t2 | TOP_IF_LONG_OR_DOUBLE); } } break; case Opcodes.LSTORE: case Opcodes.DSTORE: pop(1); t1 = pop(); set(arg, t1); set(arg + 1, TOP); if (arg > 0) { t2 = get(arg - 1); // if t2 is of kind STACK or LOCAL we cannot know its size! if (t2 == LONG || t2 == DOUBLE) { set(arg - 1, TOP); } else if ((t2 & KIND) != BASE) { set(arg - 1, t2 | TOP_IF_LONG_OR_DOUBLE); } } break; case Opcodes.IASTORE: case Opcodes.BASTORE: case Opcodes.CASTORE: case Opcodes.SASTORE: case Opcodes.FASTORE: case Opcodes.AASTORE: pop(3); break; case Opcodes.LASTORE: case Opcodes.DASTORE: pop(4); break; case Opcodes.POP: case Opcodes.IFEQ: case Opcodes.IFNE: case Opcodes.IFLT: case Opcodes.IFGE: case Opcodes.IFGT: case Opcodes.IFLE: case Opcodes.IRETURN: case Opcodes.FRETURN: case Opcodes.ARETURN: case Opcodes.TABLESWITCH: case Opcodes.LOOKUPSWITCH: case Opcodes.ATHROW: case Opcodes.MONITORENTER: case Opcodes.MONITOREXIT: case Opcodes.IFNULL: case Opcodes.IFNONNULL: pop(1); break; case Opcodes.POP2: case Opcodes.IF_ICMPEQ: case Opcodes.IF_ICMPNE: case Opcodes.IF_ICMPLT: case Opcodes.IF_ICMPGE: case Opcodes.IF_ICMPGT: case Opcodes.IF_ICMPLE: case Opcodes.IF_ACMPEQ: case Opcodes.IF_ACMPNE: case Opcodes.LRETURN: case Opcodes.DRETURN: pop(2); break; case Opcodes.DUP: t1 = pop(); push(t1); push(t1); break; case Opcodes.DUP_X1: t1 = pop(); t2 = pop(); push(t1); push(t2); push(t1); break; case Opcodes.DUP_X2: t1 = pop(); t2 = pop(); t3 = pop(); push(t1); push(t3); push(t2); push(t1); break; case Opcodes.DUP2: t1 = pop(); t2 = pop(); push(t2); push(t1); push(t2); push(t1); break; case Opcodes.DUP2_X1: t1 = pop(); t2 = pop(); t3 = pop(); push(t2); push(t1); push(t3); push(t2); push(t1); break; case Opcodes.DUP2_X2: t1 = pop(); t2 = pop(); t3 = pop(); t4 = pop(); push(t2); push(t1); push(t4); push(t3); push(t2); push(t1); break; case Opcodes.SWAP: t1 = pop(); t2 = pop(); push(t1); push(t2); break; case Opcodes.IADD: case Opcodes.ISUB: case Opcodes.IMUL: case Opcodes.IDIV: case Opcodes.IREM: case Opcodes.IAND: case Opcodes.IOR: case Opcodes.IXOR: case Opcodes.ISHL: case Opcodes.ISHR: case Opcodes.IUSHR: case Opcodes.L2I: case Opcodes.D2I: case Opcodes.FCMPL: case Opcodes.FCMPG: pop(2); push(INTEGER); break; case Opcodes.LADD: case Opcodes.LSUB: case Opcodes.LMUL: case Opcodes.LDIV: case Opcodes.LREM: case Opcodes.LAND: case Opcodes.LOR: case Opcodes.LXOR: pop(4); push(LONG); push(TOP); break; case Opcodes.FADD: case Opcodes.FSUB: case Opcodes.FMUL: case Opcodes.FDIV: case Opcodes.FREM: case Opcodes.L2F: case Opcodes.D2F: pop(2); push(FLOAT); break; case Opcodes.DADD: case Opcodes.DSUB: case Opcodes.DMUL: case Opcodes.DDIV: case Opcodes.DREM: pop(4); push(DOUBLE); push(TOP); break; case Opcodes.LSHL: case Opcodes.LSHR: case Opcodes.LUSHR: pop(3); push(LONG); push(TOP); break; case Opcodes.IINC: set(arg, INTEGER); break; case Opcodes.I2L: case Opcodes.F2L: pop(1); push(LONG); push(TOP); break; case Opcodes.I2F: pop(1); push(FLOAT); break; case Opcodes.I2D: case Opcodes.F2D: pop(1); push(DOUBLE); push(TOP); break; case Opcodes.F2I: case Opcodes.ARRAYLENGTH: case Opcodes.INSTANCEOF: pop(1); push(INTEGER); break; case Opcodes.LCMP: case Opcodes.DCMPL: case Opcodes.DCMPG: pop(4); push(INTEGER); break; case Opcodes.JSR: case Opcodes.RET: throw new RuntimeException("JSR/RET are not supported with computeFrames option"); case Opcodes.GETSTATIC: push(cw, item.strVal3); break; case Opcodes.PUTSTATIC: pop(item.strVal3); break; case Opcodes.GETFIELD: pop(1); push(cw, item.strVal3); break; case Opcodes.PUTFIELD: pop(item.strVal3); pop(); break; case Opcodes.INVOKEVIRTUAL: case Opcodes.INVOKESPECIAL: case Opcodes.INVOKESTATIC: case Opcodes.INVOKEINTERFACE: pop(item.strVal3); if (opcode != Opcodes.INVOKESTATIC) { t1 = pop(); if (opcode == Opcodes.INVOKESPECIAL && item.strVal2.charAt(0) == '<') { init(t1); } } push(cw, item.strVal3); break; case Opcodes.INVOKEDYNAMIC: pop(item.strVal2); push(cw, item.strVal2); break; case Opcodes.NEW: push(UNINITIALIZED | cw.addUninitializedType(item.strVal1, arg)); break; case Opcodes.NEWARRAY: pop(); switch (arg) { case Opcodes.T_BOOLEAN: push(ARRAY_OF | BOOLEAN); break; case Opcodes.T_CHAR: push(ARRAY_OF | CHAR); break; case Opcodes.T_BYTE: push(ARRAY_OF | BYTE); break; case Opcodes.T_SHORT: push(ARRAY_OF | SHORT); break; case Opcodes.T_INT: push(ARRAY_OF | INTEGER); break; case Opcodes.T_FLOAT: push(ARRAY_OF | FLOAT); break; case Opcodes.T_DOUBLE: push(ARRAY_OF | DOUBLE); break; // case Opcodes.T_LONG: default: push(ARRAY_OF | LONG); break; } break; case Opcodes.ANEWARRAY: String s = item.strVal1; pop(); if (s.charAt(0) == '[') { push(cw, '[' + s); } else { push(ARRAY_OF | OBJECT | cw.addType(s)); } break; case Opcodes.CHECKCAST: s = item.strVal1; pop(); if (s.charAt(0) == '[') { push(cw, s); } else { push(OBJECT | cw.addType(s)); } break; // case Opcodes.MULTIANEWARRAY: default: pop(arg); push(cw, item.strVal1); break; } }
/** * Returns the int encoding of the given type. * * @param cw the ClassWriter to which this label belongs. * @param desc a type descriptor. * @return the int encoding of the given type. */ private static int type(final ClassWriter cw, final String desc) { String t; int index = desc.charAt(0) == '(' ? desc.indexOf(')') + 1 : 0; switch (desc.charAt(index)) { case 'V': return 0; case 'Z': case 'C': case 'B': case 'S': case 'I': return INTEGER; case 'F': return FLOAT; case 'J': return LONG; case 'D': return DOUBLE; case 'L': // stores the internal name, not the descriptor! t = desc.substring(index + 1, desc.length() - 1); return OBJECT | cw.addType(t); // case '[': default: // extracts the dimensions and the element type int data; int dims = index + 1; while (desc.charAt(dims) == '[') { ++dims; } switch (desc.charAt(dims)) { case 'Z': data = BOOLEAN; break; case 'C': data = CHAR; break; case 'B': data = BYTE; break; case 'S': data = SHORT; break; case 'I': data = INTEGER; break; case 'F': data = FLOAT; break; case 'J': data = LONG; break; case 'D': data = DOUBLE; break; // case 'L': default: // stores the internal name, not the descriptor t = desc.substring(dims + 1, desc.length() - 1); data = OBJECT | cw.addType(t); } return (dims - index) << 28 | data; } }