tracemethodvisitor.java

asm的源码包 并且包含英文的文档

        final String name,
        final String desc)
    {
        buf.setLength(0);
        buf.append(tab2).append(OPCODES[opcode]).append(' ');
        appendDescriptor(INTERNAL_NAME, owner);
        buf.append('.').append(name).append(' ');
        appendDescriptor(METHOD_DESCRIPTOR, desc);
        buf.append('\n');
        text.add(buf.toString());

        if (mv != null) {
            mv.visitMethodInsn(opcode, owner, name, desc);
        }
    }

    public void visitJumpInsn(final int opcode, final Label label) {
        buf.setLength(0);
        buf.append(tab2).append(OPCODES[opcode]).append(' ');
        appendLabel(label);
        buf.append('\n');
        text.add(buf.toString());

        if (mv != null) {
            mv.visitJumpInsn(opcode, label);
        }
    }

    public void visitLabel(final Label label) {
        buf.setLength(0);
        buf.append(ltab);
        appendLabel(label);
        buf.append('\n');
        text.add(buf.toString());

        if (mv != null) {
            mv.visitLabel(label);
        }
    }

    public void visitLdcInsn(final Object cst) {
        buf.setLength(0);
        buf.append(tab2).append("LDC ");
        if (cst instanceof String) {
            AbstractVisitor.appendString(buf, (String) cst);
        } else if (cst instanceof Type) {
            buf.append(((Type) cst).getDescriptor() + ".class");
        } else {
            buf.append(cst);
        }
        buf.append('\n');
        text.add(buf.toString());

        if (mv != null) {
            mv.visitLdcInsn(cst);
        }
    }

    public void visitIincInsn(final int var, final int increment) {
        buf.setLength(0);
        buf.append(tab2)
                .append("IINC ")
                .append(var)
                .append(' ')
                .append(increment)
                .append('\n');
        text.add(buf.toString());

        if (mv != null) {
            mv.visitIincInsn(var, increment);
        }
    }

    public void visitTableSwitchInsn(
        final int min,
        final int max,
        final Label dflt,
        final Label labels[])
    {
        buf.setLength(0);
        buf.append(tab2).append("TABLESWITCH\n");
        for (int i = 0; i < labels.length; ++i) {
            buf.append(tab3).append(min + i).append(": ");
            appendLabel(labels[i]);
            buf.append('\n');
        }
        buf.append(tab3).append("default: ");
        appendLabel(dflt);
        buf.append('\n');
        text.add(buf.toString());

        if (mv != null) {
            mv.visitTableSwitchInsn(min, max, dflt, labels);
        }
    }

    public void visitLookupSwitchInsn(
        final Label dflt,
        final int keys[],
        final Label labels[])
    {
        buf.setLength(0);
        buf.append(tab2).append("LOOKUPSWITCH\n");
        for (int i = 0; i < labels.length; ++i) {
            buf.append(tab3).append(keys[i]).append(": ");
            appendLabel(labels[i]);
            buf.append('\n');
        }
        buf.append(tab3).append("default: ");
        appendLabel(dflt);
        buf.append('\n');
        text.add(buf.toString());

        if (mv != null) {
            mv.visitLookupSwitchInsn(dflt, keys, labels);
        }
    }

    public void visitMultiANewArrayInsn(final String desc, final int dims) {
        buf.setLength(0);
        buf.append(tab2).append("MULTIANEWARRAY ");
        appendDescriptor(FIELD_DESCRIPTOR, desc);
        buf.append(' ').append(dims).append('\n');
        text.add(buf.toString());

        if (mv != null) {
            mv.visitMultiANewArrayInsn(desc, dims);
        }
    }

    public void visitTryCatchBlock(
        final Label start,
        final Label end,
        final Label handler,
        final String type)
    {
        buf.setLength(0);
        buf.append(tab2).append("TRYCATCHBLOCK ");
        appendLabel(start);
        buf.append(' ');
        appendLabel(end);
        buf.append(' ');
        appendLabel(handler);
        buf.append(' ');
        appendDescriptor(INTERNAL_NAME, type);
        buf.append('\n');
        text.add(buf.toString());

        if (mv != null) {
            mv.visitTryCatchBlock(start, end, handler, type);
        }
    }

    public void visitLocalVariable(
        final String name,
        final String desc,
        final String signature,
        final Label start,
        final Label end,
        final int index)
    {
        buf.setLength(0);
        buf.append(tab2).append("LOCALVARIABLE ").append(name).append(' ');
        appendDescriptor(FIELD_DESCRIPTOR, desc);
        buf.append(' ');
        appendLabel(start);
        buf.append(' ');
        appendLabel(end);
        buf.append(' ').append(index).append('\n');

        if (signature != null) {
            buf.append(tab2);
            appendDescriptor(FIELD_SIGNATURE, signature);

            TraceSignatureVisitor sv = new TraceSignatureVisitor(0);
            SignatureReader r = new SignatureReader(signature);
            r.acceptType(sv);
            buf.append(tab2)
                    .append("// declaration: ")
                    .append(sv.getDeclaration())
                    .append('\n');
        }
        text.add(buf.toString());

        if (mv != null) {
            mv.visitLocalVariable(name, desc, signature, start, end, index);
        }
    }

    public void visitLineNumber(final int line, final Label start) {
        buf.setLength(0);
        buf.append(tab2).append("LINENUMBER ").append(line).append(' ');
        appendLabel(start);
        buf.append('\n');
        text.add(buf.toString());

        if (mv != null) {
            mv.visitLineNumber(line, start);
        }
    }

    public void visitMaxs(final int maxStack, final int maxLocals) {
        buf.setLength(0);
        buf.append(tab2).append("MAXSTACK = ").append(maxStack).append('\n');
        text.add(buf.toString());

        buf.setLength(0);
        buf.append(tab2).append("MAXLOCALS = ").append(maxLocals).append('\n');
        text.add(buf.toString());

        if (mv != null) {
            mv.visitMaxs(maxStack, maxLocals);
        }
    }

    public void visitEnd() {
        super.visitEnd();

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

    // ------------------------------------------------------------------------
    // Utility methods
    // ------------------------------------------------------------------------

    private void appendFrameTypes(final int n, final Object[] o) {
        for (int i = 0; i < n; ++i) {
            if (i > 0) {
                buf.append(' ');
            }
            if (o[i] instanceof String) {
                String desc = (String) o[i];
                if (desc.startsWith("[")) {
                    appendDescriptor(FIELD_DESCRIPTOR, desc);
                } else {
                    appendDescriptor(INTERNAL_NAME, desc);
                }
            } else if (o[i] instanceof Integer) {
                switch (((Integer) o[i]).intValue()) {
                    case 0:
                        appendDescriptor(FIELD_DESCRIPTOR, "T");
                        break;
                    case 1:
                        appendDescriptor(FIELD_DESCRIPTOR, "I");
                        break;
                    case 2:
                        appendDescriptor(FIELD_DESCRIPTOR, "F");
                        break;
                    case 3:
                        appendDescriptor(FIELD_DESCRIPTOR, "D");
                        break;
                    case 4:
                        appendDescriptor(FIELD_DESCRIPTOR, "J");
                        break;
                    case 5:
                        appendDescriptor(FIELD_DESCRIPTOR, "N");
                        break;
                    case 6:
                        appendDescriptor(FIELD_DESCRIPTOR, "U");
                        break;
                }
            } else {
                appendLabel((Label) o[i]);
            }
        }
    }

    /**
     * Appends the name of the given label to {@link #buf buf}. Creates a new
     * label name if the given label does not yet have one.
     * 
     * @param l a label.
     */
    protected void appendLabel(final Label l) {
        String name = (String) labelNames.get(l);
        if (name == null) {
            name = "L" + labelNames.size();
            labelNames.put(l, name);
        }
        buf.append(name);
    }
}