classreader.java

asm的源码包 并且包含英文的文档

                                    frameMode = Opcodes.F_APPEND;
                                    frameLocalDiff = tag
                                            - MethodWriter.SAME_FRAME_EXTENDED;
                                    frameLocalCount += frameLocalDiff;
                                    frameStackCount = 0;
                                } else { // if (tag == FULL_FRAME) {
                                    frameMode = Opcodes.F_FULL;
                                    n = frameLocalDiff = frameLocalCount = readUnsignedShort(stackMap);
                                    stackMap += 2;
                                    for (j = 0; n > 0; n--) {
                                        stackMap = readFrameType(frameLocal,
                                                j++,
                                                stackMap,
                                                c,
                                                labels);
                                    }
                                    n = frameStackCount = readUnsignedShort(stackMap);
                                    stackMap += 2;
                                    for (j = 0; n > 0; n--) {
                                        stackMap = readFrameType(frameStack,
                                                j++,
                                                stackMap,
                                                c,
                                                labels);
                                    }
                                }
                            }
                            frameOffset += delta + 1;
                            if (labels[frameOffset] == null) {
                                labels[frameOffset] = new Label();
                            }

                            --frameCount;
                        } else {
                            frameLocal = null;
                        }
                    }

                    int opcode = b[v] & 0xFF;
                    switch (ClassWriter.TYPE[opcode]) {
                        case ClassWriter.NOARG_INSN:
                            mv.visitInsn(opcode);
                            v += 1;
                            break;
                        case ClassWriter.IMPLVAR_INSN:
                            if (opcode > Opcodes.ISTORE) {
                                opcode -= 59; // ISTORE_0
                                mv.visitVarInsn(Opcodes.ISTORE + (opcode >> 2),
                                        opcode & 0x3);
                            } else {
                                opcode -= 26; // ILOAD_0
                                mv.visitVarInsn(Opcodes.ILOAD + (opcode >> 2),
                                        opcode & 0x3);
                            }
                            v += 1;
                            break;
                        case ClassWriter.LABEL_INSN:
                            mv.visitJumpInsn(opcode, labels[w
                                    + readShort(v + 1)]);
                            v += 3;
                            break;
                        case ClassWriter.LABELW_INSN:
                            mv.visitJumpInsn(opcode - 33, labels[w
                                    + readInt(v + 1)]);
                            v += 5;
                            break;
                        case ClassWriter.WIDE_INSN:
                            opcode = b[v + 1] & 0xFF;
                            if (opcode == Opcodes.IINC) {
                                mv.visitIincInsn(readUnsignedShort(v + 2),
                                        readShort(v + 4));
                                v += 6;
                            } else {
                                mv.visitVarInsn(opcode,
                                        readUnsignedShort(v + 2));
                                v += 4;
                            }
                            break;
                        case ClassWriter.TABL_INSN:
                            // skips 0 to 3 padding bytes
                            v = v + 4 - (w & 3);
                            // reads instruction
                            label = w + readInt(v);
                            int min = readInt(v + 4);
                            int max = readInt(v + 8);
                            v += 12;
                            Label[] table = new Label[max - min + 1];
                            for (j = 0; j < table.length; ++j) {
                                table[j] = labels[w + readInt(v)];
                                v += 4;
                            }
                            mv.visitTableSwitchInsn(min,
                                    max,
                                    labels[label],
                                    table);
                            break;
                        case ClassWriter.LOOK_INSN:
                            // skips 0 to 3 padding bytes
                            v = v + 4 - (w & 3);
                            // reads instruction
                            label = w + readInt(v);
                            j = readInt(v + 4);
                            v += 8;
                            int[] keys = new int[j];
                            Label[] values = new Label[j];
                            for (j = 0; j < keys.length; ++j) {
                                keys[j] = readInt(v);
                                values[j] = labels[w + readInt(v + 4)];
                                v += 8;
                            }
                            mv.visitLookupSwitchInsn(labels[label],
                                    keys,
                                    values);
                            break;
                        case ClassWriter.VAR_INSN:
                            mv.visitVarInsn(opcode, b[v + 1] & 0xFF);
                            v += 2;
                            break;
                        case ClassWriter.SBYTE_INSN:
                            mv.visitIntInsn(opcode, b[v + 1]);
                            v += 2;
                            break;
                        case ClassWriter.SHORT_INSN:
                            mv.visitIntInsn(opcode, readShort(v + 1));
                            v += 3;
                            break;
                        case ClassWriter.LDC_INSN:
                            mv.visitLdcInsn(readConst(b[v + 1] & 0xFF, c));
                            v += 2;
                            break;
                        case ClassWriter.LDCW_INSN:
                            mv.visitLdcInsn(readConst(readUnsignedShort(v + 1),
                                    c));
                            v += 3;
                            break;
                        case ClassWriter.FIELDORMETH_INSN:
                        case ClassWriter.ITFMETH_INSN:
                            int cpIndex = items[readUnsignedShort(v + 1)];
                            String iowner = readClass(cpIndex, c);
                            cpIndex = items[readUnsignedShort(cpIndex + 2)];
                            String iname = readUTF8(cpIndex, c);
                            String idesc = readUTF8(cpIndex + 2, c);
                            if (opcode < Opcodes.INVOKEVIRTUAL) {
                                mv.visitFieldInsn(opcode, iowner, iname, idesc);
                            } else {
                                mv.visitMethodInsn(opcode, iowner, iname, idesc);
                            }
                            if (opcode == Opcodes.INVOKEINTERFACE) {
                                v += 5;
                            } else {
                                v += 3;
                            }
                            break;
                        case ClassWriter.TYPE_INSN:
                            mv.visitTypeInsn(opcode, readClass(v + 1, c));
                            v += 3;
                            break;
                        case ClassWriter.IINC_INSN:
                            mv.visitIincInsn(b[v + 1] & 0xFF, b[v + 2]);
                            v += 3;
                            break;
                        // case MANA_INSN:
                        default:
                            mv.visitMultiANewArrayInsn(readClass(v + 1, c),
                                    b[v + 3] & 0xFF);
                            v += 4;
                            break;
                    }
                }
                l = labels[codeEnd - codeStart];
                if (l != null) {
                    mv.visitLabel(l);
                }
                // visits the local variable tables
                if (!skipDebug && varTable != 0) {
                    int[] typeTable = null;
                    if (varTypeTable != 0) {
                        k = readUnsignedShort(varTypeTable) * 3;
                        w = varTypeTable + 2;
                        typeTable = new int[k];
                        while (k > 0) {
                            typeTable[--k] = w + 6; // signature
                            typeTable[--k] = readUnsignedShort(w + 8); // index
                            typeTable[--k] = readUnsignedShort(w); // start
                            w += 10;
                        }
                    }
                    k = readUnsignedShort(varTable);
                    w = varTable + 2;
                    for (; k > 0; --k) {
                        int start = readUnsignedShort(w);
                        int length = readUnsignedShort(w + 2);
                        int index = readUnsignedShort(w + 8);
                        String vsignature = null;
                        if (typeTable != null) {
                            for (int a = 0; a < typeTable.length; a += 3) {
                                if (typeTable[a] == start
                                        && typeTable[a + 1] == index)
                                {
                                    vsignature = readUTF8(typeTable[a + 2], c);
                                    break;
                                }
                            }
                        }
                        mv.visitLocalVariable(readUTF8(w + 4, c),
                                readUTF8(w + 6, c),
                                vsignature,
                                labels[start],
                                labels[start + length],
                                index);
                        w += 10;
                    }
                }
                // visits the other attributes
                while (cattrs != null) {
                    attr = cattrs.next;
                    cattrs.next = null;
                    mv.visitAttribute(cattrs);
                    cattrs = attr;
                }
                // visits the max stack and max locals values
                mv.visitMaxs(maxStack, maxLocals);
            }

            if (mv != null) {
                mv.visitEnd();
            }
        }

        // visits the end of the class
        classVisitor.visitEnd();
    }

    /**
     * Reads parameter annotations and makes the given visitor visit them.
     * 
     * @param v start offset in {@link #b b} of the annotations to be read.
     * @param buf buffer to be used to call {@link #readUTF8 readUTF8},
     *        {@link #readClass(int,char[]) readClass} or
     *        {@link #readConst readConst}.
     * @param visible <tt>true</tt> if the annotations to be read are visible
     *        at runtime.
     * @param mv the visitor that must visit the annotations.
     */
    private void readParameterAnnotations(
        int v,
        final char[] buf,
        final boolean visible,
        final MethodVisitor mv)
    {
        int n = b[v++] & 0xFF;
        for (int i = 0; i < n; ++i) {
            int j = readUnsignedShort(v);
            v += 2;
            for (; j > 0; --j) {
                v = readAnnotationValues(v + 2,
                        buf,
                        true,
                        mv.visitParameterAnnotation(i,
                                readUTF8(v, buf),
                                visible));
            }
        }
    }

    /**
     * Reads the values of an annotation and makes the given visitor visit them.
     * 
     * @param v the start offset in {@link #b b} of the values to be read
     *        (including the unsigned short that gives the number of values).
     * @param buf buffer to be used to call {@link #readUTF8 readUTF8},
     *        {@link #readClass(int,char[]) readClass} or
     *        {@link #readConst readConst}.
     * @param named if the annotation values are named or not.
     * @param av the visitor that must visit the values.
     * @return the end offset of the annotation values.
     */
    private int readAnnotationValues(
        int v,
        final char[] buf,
        final boolean named,
        final AnnotationVisitor av)
    {
        int i = readUnsignedShort(v);
        v += 2;
        if (named) {
            for (; i > 0; --i) {
                v = readAnnotationValue(v + 2, buf, readUTF8(v, buf), av);
            }
        } else {
            for (; i > 0; --i) {
                v = readAnnotationValue(v, buf, null, av);
            }
        }
        if (av != null) {
            av.visitEnd();
        }
        return v;
    }

    /**
     * Reads a value of an annotation and makes the given visitor visit it.
     * 
     * @