Java tutorial
/******************************************************************************* * Copyright (c) 2014, 2016 IBM Corporation. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html *******************************************************************************/ package com.ibm.layout; import org.objectweb.asm.ClassWriter; import org.objectweb.asm.FieldVisitor; import org.objectweb.asm.Label; import org.objectweb.asm.MethodVisitor; import org.objectweb.asm.Opcodes; class GenLayout implements Opcodes { private final Class<? extends Layout> clazz; private final String interfaceClassName; private final String implClassName; /** * Instantiate GenLayout * * @param elementInterfaceClass, element type for Array */ public GenLayout(Class<? extends Layout> clazz) { this.clazz = clazz; this.interfaceClassName = ImplHelper.getInterfaceClassName(clazz); this.implClassName = ImplHelper.getImplClassName(clazz); } private long getClassSize(ImplHelper.FieldDesc[] fields) { long classSize = 0; for (ImplHelper.FieldDesc f : fields) { classSize += f.size; } return classSize; } /** * Generate bytecodes for runtime class * * @return byte array containing bytecodes for runtime class * @throws Exception */ public byte[] genBytecode() throws Exception { ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS); FieldVisitor fv = null; MethodVisitor mv = null; ImplHelper.FieldDesc[] fieldDesc = ImplHelper.getFieldDesc(clazz); boolean isVariableLengthLayout = false; final boolean itf = false; { mv = cw.visitMethod(ACC_PUBLIC, "sizeof", "()J", null, null); mv.visitCode(); mv.visitLdcInsn(new Long(getClassSize(fieldDesc))); mv.visitInsn(LRETURN); mv.visitMaxs(2, 1); mv.visitEnd(); } cw.visit(V1_8, ACC_FINAL + ACC_SUPER, implClassName, null, "java/lang/Object", new String[] { interfaceClassName }); { mv = cw.visitMethod(0, "<init>", "()V", null, null); mv.visitCode(); mv.visitVarInsn(ALOAD, 0); mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false); mv.visitInsn(RETURN); mv.visitMaxs(1, 1); mv.visitEnd(); } // getters for (int i = 0; i < fieldDesc.length; i++) { if (!ImplHelper.isPointerType(fieldDesc[i].rawType)) { if (ImplHelper.isTypePrimitive(fieldDesc[i].sig)) { mv = cw.visitMethod(ACC_PUBLIC, fieldDesc[i].name, "()" + fieldDesc[i].sig, null, null); mv.visitCode(); mv.visitFieldInsn(GETSTATIC, implClassName, "unsafe", "Lsun/misc/Unsafe;"); mv.visitVarInsn(ALOAD, 0); mv.visitFieldInsn(GETFIELD, implClassName, "location", "Lcom/ibm/layout/Location;"); mv.visitMethodInsn(INVOKEVIRTUAL, "com/ibm/layout/Location", "getData", "()[B", itf); mv.visitVarInsn(ALOAD, 0); mv.visitFieldInsn(GETFIELD, implClassName, "location", "Lcom/ibm/layout/Location;"); mv.visitMethodInsn(INVOKEVIRTUAL, "com/ibm/layout/Location", "getOffset", "()J", itf); mv.visitLdcInsn(fieldDesc[i].offset); mv.visitInsn(LADD); mv.visitMethodInsn(INVOKEVIRTUAL, "sun/misc/Unsafe", "get" + ImplHelper.fieldSig2MethodType(fieldDesc[i].sig), "(Ljava/lang/Object;J)" + fieldDesc[i].sig, itf); if (fieldDesc[i].sig == "D") { mv.visitInsn(DRETURN); } else if (fieldDesc[i].sig == "J") { mv.visitInsn(LRETURN); } else if (fieldDesc[i].sig == "F") { mv.visitInsn(FRETURN); } else { mv.visitInsn(IRETURN); } mv.visitMaxs(6, 1); mv.visitEnd(); } else if (fieldDesc[i].repeatCountMember != null) { { isVariableLengthLayout = true; ImplHelper.FieldDesc repeatCountField = ImplHelper.findField(fieldDesc[i].repeatCountMember, fieldDesc); mv = cw.visitMethod(ACC_PUBLIC, fieldDesc[i].name, "()" + fieldDesc[i].sig, "()" + fieldDesc[i].elementImpl, null); mv.visitCode(); if ("" != fieldDesc[i].elementImpl) { mv.visitTypeInsn(NEW, fieldDesc[i].elementImpl); mv.visitInsn(DUP); mv.visitMethodInsn(INVOKESPECIAL, fieldDesc[i].elementImpl, "<init>", "()V", false); mv.visitVarInsn(ASTORE, 1); mv.visitTypeInsn(NEW, fieldDesc[i].impl); mv.visitInsn(DUP); mv.visitVarInsn(ALOAD, 0); mv.visitMethodInsn(INVOKEVIRTUAL, implClassName, fieldDesc[i].repeatCountMember, "()" + repeatCountField.sig, false); if (!repeatCountField.sig.equals("J")) { mv.visitInsn(I2L); } mv.visitVarInsn(ALOAD, 1); mv.visitMethodInsn(INVOKEVIRTUAL, fieldDesc[i].elementImpl, "sizeof", "()J", false); mv.visitMethodInsn(INVOKESPECIAL, fieldDesc[i].impl, "<init>", "(JJ)V", false); mv.visitVarInsn(ASTORE, 2); mv.visitTypeInsn(NEW, "com/ibm/layout/Location"); mv.visitInsn(DUP); mv.visitVarInsn(ALOAD, 0); mv.visitFieldInsn(GETFIELD, implClassName, "location", "Lcom/ibm/layout/Location;"); mv.visitLdcInsn(fieldDesc[i].offset); mv.visitMethodInsn(INVOKESPECIAL, "com/ibm/layout/Location", "<init>", "(Lcom/ibm/layout/Location;J)V", false); mv.visitVarInsn(ASTORE, 3); mv.visitVarInsn(ALOAD, 2); mv.visitVarInsn(ALOAD, 3); mv.visitMethodInsn(INVOKEINTERFACE, "com/ibm/layout/VLArray", "bindLocation", "(Lcom/ibm/layout/Location;)V", true); mv.visitVarInsn(ALOAD, 2); mv.visitInsn(ARETURN); mv.visitMaxs(6, 4); mv.visitEnd(); } else { throw new RuntimeException("primitive VLAs are unsupported"); } { mv = cw.visitMethod(ACC_PUBLIC, "bindLocation", "(Lcom/ibm/layout/Location;" + repeatCountField.sig + ")V", null, new String[] { "java/lang/UnsupportedOperationException" }); mv.visitCode(); mv.visitVarInsn(ALOAD, 1); mv.visitVarInsn(ALOAD, 0); mv.visitMethodInsn(INVOKEVIRTUAL, implClassName, "sizeof", "()J", false); mv.visitMethodInsn(INVOKEVIRTUAL, "com/ibm/layout/Location", "checkDataFits", "(J)Z", false); Label l0 = new Label(); mv.visitJumpInsn(IFEQ, l0); mv.visitVarInsn(ALOAD, 0); mv.visitVarInsn(ALOAD, 1); mv.visitFieldInsn(PUTFIELD, implClassName, "location", "Lcom/ibm/layout/Location;"); mv.visitLabel(l0); mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null); mv.visitVarInsn(ALOAD, 0); if (repeatCountField.sig.equals("J")) { mv.visitVarInsn(LLOAD, 2); } else { mv.visitVarInsn(ILOAD, 2); } mv.visitMethodInsn(INVOKEVIRTUAL, implClassName, fieldDesc[i].repeatCountMember, "(" + repeatCountField.sig + ")V", false); mv.visitInsn(RETURN); mv.visitMaxs(3, 3); mv.visitEnd(); } } } else if (fieldDesc[i].dims == null) { /* nested field */ mv = cw.visitMethod(ACC_PUBLIC, fieldDesc[i].name, "()" + fieldDesc[i].sig, null, null); mv.visitCode(); mv.visitTypeInsn(NEW, ImplHelper.getImplClassName(fieldDesc[i].rawType)); mv.visitInsn(DUP); mv.visitMethodInsn(INVOKESPECIAL, ImplHelper.getImplClassName(fieldDesc[i].rawType), "<init>", "()V", itf); mv.visitVarInsn(ASTORE, 1); mv.visitTypeInsn(NEW, "com/ibm/layout/Location"); mv.visitInsn(DUP); mv.visitVarInsn(ALOAD, 0); mv.visitFieldInsn(GETFIELD, this.implClassName, "location", "Lcom/ibm/layout/Location;"); mv.visitLdcInsn(fieldDesc[i].offset); mv.visitMethodInsn(INVOKESPECIAL, "com/ibm/layout/Location", "<init>", "(Lcom/ibm/layout/Location;J)V", itf); mv.visitVarInsn(ASTORE, 2); mv.visitVarInsn(ALOAD, 1); mv.visitVarInsn(ALOAD, 2); mv.visitMethodInsn(INVOKEVIRTUAL, ImplHelper.getImplClassName(fieldDesc[i].rawType), "bindLocation", "(Lcom/ibm/layout/Location;)V", itf); mv.visitVarInsn(ALOAD, 1); mv.visitInsn(ARETURN); mv.visitMaxs(5, 3); mv.visitEnd(); } else if (fieldDesc[i].dims.length == 1) { mv = cw.visitMethod(ACC_PUBLIC, fieldDesc[i].name, "()" + fieldDesc[i].sig, "()" + fieldDesc[i].sigGeneric, null); mv.visitCode(); if ("" != fieldDesc[i].elementImpl) { mv.visitTypeInsn(NEW, fieldDesc[i].elementImpl); mv.visitInsn(DUP); mv.visitMethodInsn(INVOKESPECIAL, fieldDesc[i].elementImpl, "<init>", "()V", itf); mv.visitVarInsn(ASTORE, 1); mv.visitTypeInsn(NEW, fieldDesc[i].impl); mv.visitInsn(DUP); mv.visitLdcInsn(fieldDesc[i].dims[0]); mv.visitVarInsn(ALOAD, 1); mv.visitMethodInsn(INVOKEVIRTUAL, fieldDesc[i].elementImpl, "sizeof", "()J", itf); mv.visitMethodInsn(INVOKESPECIAL, fieldDesc[i].impl, "<init>", "(JJ)V", itf); mv.visitVarInsn(ASTORE, 2); mv.visitTypeInsn(NEW, "com/ibm/layout/Location"); mv.visitInsn(DUP); mv.visitVarInsn(ALOAD, 0); mv.visitFieldInsn(GETFIELD, this.implClassName, "location", "Lcom/ibm/layout/Location;"); mv.visitLdcInsn(fieldDesc[i].offset); mv.visitMethodInsn(INVOKESPECIAL, "com/ibm/layout/Location", "<init>", "(Lcom/ibm/layout/Location;J)V", itf); mv.visitVarInsn(ASTORE, 3); mv.visitVarInsn(ALOAD, 2); mv.visitVarInsn(ALOAD, 3); mv.visitMethodInsn(INVOKEVIRTUAL, fieldDesc[i].impl, "bindLocation", "(Lcom/ibm/layout/Location;)V", itf); mv.visitVarInsn(ALOAD, 2); mv.visitInsn(ARETURN); mv.visitMaxs(6, 4); mv.visitEnd(); } else { mv.visitTypeInsn(NEW, fieldDesc[i].impl); mv.visitInsn(DUP); mv.visitLdcInsn(fieldDesc[i].dims[0]); mv.visitMethodInsn(INVOKESPECIAL, fieldDesc[i].impl, "<init>", "(J)V", itf); mv.visitVarInsn(ASTORE, 1); mv.visitTypeInsn(NEW, "com/ibm/layout/Location"); mv.visitInsn(DUP); mv.visitVarInsn(ALOAD, 0); mv.visitFieldInsn(GETFIELD, this.implClassName, "location", "Lcom/ibm/layout/Location;"); mv.visitLdcInsn(fieldDesc[i].offset); mv.visitMethodInsn(INVOKESPECIAL, "com/ibm/layout/Location", "<init>", "(Lcom/ibm/layout/Location;J)V", itf); mv.visitVarInsn(ASTORE, 2); mv.visitVarInsn(ALOAD, 1); mv.visitVarInsn(ALOAD, 2); mv.visitMethodInsn(INVOKEVIRTUAL, fieldDesc[i].impl, "bindLocation", "(Lcom/ibm/layout/Location;)V", itf); mv.visitVarInsn(ALOAD, 1); mv.visitInsn(ARETURN); mv.visitMaxs(5, 3); mv.visitEnd(); } } else if (fieldDesc[i].dims.length == 2) { if ("" != fieldDesc[i].elementImpl) { mv = cw.visitMethod(ACC_PUBLIC, fieldDesc[i].name, "()" + fieldDesc[i].sig, "()" + fieldDesc[i].sigGeneric, null); mv.visitCode(); mv.visitTypeInsn(NEW, fieldDesc[i].elementImpl); mv.visitInsn(DUP); mv.visitMethodInsn(INVOKESPECIAL, fieldDesc[i].elementImpl, "<init>", "()V", itf); mv.visitVarInsn(ASTORE, 1); mv.visitTypeInsn(NEW, fieldDesc[i].impl); mv.visitInsn(DUP); mv.visitLdcInsn(fieldDesc[i].dims[0]); mv.visitLdcInsn(fieldDesc[i].dims[1]); mv.visitVarInsn(ALOAD, 1); mv.visitMethodInsn(INVOKEVIRTUAL, fieldDesc[i].elementImpl, "sizeof", "()J", itf); mv.visitMethodInsn(INVOKESPECIAL, fieldDesc[i].impl, "<init>", "(JJJ)V", itf); mv.visitVarInsn(ASTORE, 2); mv.visitTypeInsn(NEW, "com/ibm/layout/Location"); mv.visitInsn(DUP); mv.visitVarInsn(ALOAD, 0); mv.visitFieldInsn(GETFIELD, this.implClassName, "location", "Lcom/ibm/layout/Location;"); mv.visitLdcInsn(fieldDesc[i].offset); mv.visitMethodInsn(INVOKESPECIAL, "com/ibm/layout/Location", "<init>", "(Lcom/ibm/layout/Location;J)V", itf); mv.visitVarInsn(ASTORE, 3); mv.visitVarInsn(ALOAD, 2); mv.visitVarInsn(ALOAD, 3); mv.visitMethodInsn(INVOKEVIRTUAL, fieldDesc[i].impl, "bindLocation", "(Lcom/ibm/layout/Location;)V", itf); mv.visitVarInsn(ALOAD, 2); mv.visitInsn(ARETURN); mv.visitMaxs(8, 4); mv.visitEnd(); } else { mv = cw.visitMethod(ACC_PUBLIC, fieldDesc[i].name, "()" + fieldDesc[i].sig, "()" + fieldDesc[i].sigGeneric, null); mv.visitCode(); mv.visitTypeInsn(NEW, fieldDesc[i].impl); mv.visitInsn(DUP); mv.visitLdcInsn(fieldDesc[i].dims[0]); mv.visitLdcInsn(fieldDesc[i].dims[1]); mv.visitMethodInsn(INVOKESPECIAL, fieldDesc[i].impl, "<init>", "(JJ)V", itf); mv.visitVarInsn(ASTORE, 1); mv.visitTypeInsn(NEW, "com/ibm/layout/Location"); mv.visitInsn(DUP); mv.visitVarInsn(ALOAD, 0); mv.visitFieldInsn(GETFIELD, this.implClassName, "location", "Lcom/ibm/layout/Location;"); mv.visitLdcInsn(fieldDesc[i].offset); mv.visitMethodInsn(INVOKESPECIAL, "com/ibm/layout/Location", "<init>", "(Lcom/ibm/layout/Location;J)V", itf); mv.visitVarInsn(ASTORE, 2); mv.visitVarInsn(ALOAD, 1); mv.visitVarInsn(ALOAD, 2); mv.visitMethodInsn(INVOKEVIRTUAL, fieldDesc[i].impl, "bindLocation", "(Lcom/ibm/layout/Location;)V", itf); mv.visitVarInsn(ALOAD, 1); mv.visitInsn(ARETURN); mv.visitMaxs(6, 3); mv.visitEnd(); } } } } // setters for (int i = 0; i < fieldDesc.length; i++) { if (ImplHelper.isTypePrimitive(fieldDesc[i].sig)) { mv = cw.visitMethod(ACC_PUBLIC, fieldDesc[i].name, "(" + fieldDesc[i].sig + ")V", null, null); mv.visitCode(); mv.visitFieldInsn(GETSTATIC, implClassName, "unsafe", "Lsun/misc/Unsafe;"); mv.visitVarInsn(ALOAD, 0); mv.visitFieldInsn(GETFIELD, implClassName, "location", "Lcom/ibm/layout/Location;"); mv.visitMethodInsn(INVOKEVIRTUAL, "com/ibm/layout/Location", "getData", "()[B", itf); mv.visitVarInsn(ALOAD, 0); mv.visitFieldInsn(GETFIELD, implClassName, "location", "Lcom/ibm/layout/Location;"); mv.visitMethodInsn(INVOKEVIRTUAL, "com/ibm/layout/Location", "getOffset", "()J", itf); mv.visitLdcInsn(fieldDesc[i].offset); mv.visitInsn(LADD); if (fieldDesc[i].sig == "D") { mv.visitVarInsn(DLOAD, 1); } else if (fieldDesc[i].sig == "J") { mv.visitVarInsn(LLOAD, 1); } else if (fieldDesc[i].sig == "F") { mv.visitVarInsn(FLOAD, 1); } else { mv.visitVarInsn(ILOAD, 1); } mv.visitMethodInsn(INVOKEVIRTUAL, "sun/misc/Unsafe", "put" + ImplHelper.fieldSig2MethodType(fieldDesc[i].sig), "(Ljava/lang/Object;J" + fieldDesc[i].sig + ")V", itf); mv.visitInsn(RETURN); mv.visitMaxs(6, 2); mv.visitEnd(); } } { mv = cw.visitMethod(ACC_PUBLIC, "copyFrom", "(L" + implClassName + ";)V", null, null); mv.visitCode(); mv.visitVarInsn(ALOAD, 0); mv.visitVarInsn(ALOAD, 1); mv.visitMethodInsn(INVOKESPECIAL, implClassName, "copyFrom", "(Lcom/ibm/layout/Layout;)V", itf); mv.visitInsn(RETURN); mv.visitMaxs(2, 2); mv.visitEnd(); } { mv = cw.visitMethod(ACC_PUBLIC, "toString", "()Ljava/lang/String;", null, null); mv.visitCode(); mv.visitTypeInsn(NEW, "java/lang/StringBuilder"); mv.visitInsn(DUP); mv.visitLdcInsn("("); mv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "(Ljava/lang/String;)V", false); for (int i = 0; i < fieldDesc.length; i++) { if (ImplHelper.isTypePrimitive(fieldDesc[i].sig)) { mv.visitLdcInsn(fieldDesc[i].name + ": "); mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false); mv.visitVarInsn(ALOAD, 0); mv.visitMethodInsn(INVOKEVIRTUAL, implClassName, fieldDesc[i].name, "()" + fieldDesc[i].sig, false); mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(" + ImplHelper.getByteCodeSig(fieldDesc[i].sig) + ")Ljava/lang/StringBuilder;", false); if (i < (fieldDesc.length - 1)) { mv.visitLdcInsn(", "); mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false); } } else { mv.visitVarInsn(ALOAD, 0); mv.visitMethodInsn(INVOKEVIRTUAL, implClassName, fieldDesc[i].name, "()" + fieldDesc[i].sig, false); mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Object", "toString", "()Ljava/lang/String;", false); mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false); } } mv.visitLdcInsn(")"); mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false); mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;", false); mv.visitInsn(ARETURN); mv.visitMaxs(3, 1); mv.visitEnd(); } ImplHelper.genLayoutTypeImpl(cw, mv, fv, implClassName, isVariableLengthLayout); ImplHelper.getLayoutImpl(cw, mv, implClassName); cw.visitEnd(); return cw.toByteArray(); } }