Skip to content

修复access-inline插件遇到access$方法中只有LDC指令时的NPE问题 #42

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 2 commits into
base: master
Choose a base branch
from
Open

修复access-inline插件遇到access$方法中只有LDC指令时的NPE问题 #42

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
e4d3462
修复access-inline插件遇到access$方法中带LDC指令时的NPE问题
Jul 2, 2020
eac1a5a
PreProcessClassVisitor中的MethodVisitor替换为MethodNode
Jul 6, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
196 changes: 36 additions & 160 deletions .../src/main/java/com/ss/android/ugc/bytex/access_inline/visitor/PreProcessClassVisitor.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9,28 +9,17 @@
import com.ss.android.ugc.bytex.access_inline.Context;
import com.ss.android.ugc.bytex.access_inline.ShouldSkipInlineException;

import org.objectweb.asm.Handle;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.FieldInsnNode;
import org.objectweb.asm.tree.IincInsnNode;
import org.objectweb.asm.tree.InsnNode;
import org.objectweb.asm.tree.IntInsnNode;
import org.objectweb.asm.tree.InvokeDynamicInsnNode;
import org.objectweb.asm.tree.JumpInsnNode;
import org.objectweb.asm.tree.LabelNode;
import org.objectweb.asm.tree.LdcInsnNode;
import org.objectweb.asm.tree.LookupSwitchInsnNode;
import org.objectweb.asm.tree.InsnList;
import org.objectweb.asm.tree.MethodInsnNode;
import org.objectweb.asm.tree.MultiANewArrayInsnNode;
import org.objectweb.asm.tree.TableSwitchInsnNode;
import org.objectweb.asm.tree.TypeInsnNode;
import org.objectweb.asm.tree.VarInsnNode;
import org.objectweb.asm.tree.MethodNode;

import java.util.ArrayList;
import java.util.List;
import java.util.ListIterator;

public class PreProcessClassVisitor extends BaseClassVisitor {

Expand Down Expand Up @@ -58,158 +47,21 @@ public MethodVisitor visitMethod(int access, String name, String desc, String si
MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions);
if (!fromAndroidSDK && TypeUtil.isSynthetic(access) && TypeUtil.isStatic(access) && name.startsWith("access$")) {
Access$MethodEntity access$MethodEntity = new Access$MethodEntity(className, name, desc);
return new RefineAccess$MethodVisitor(mv, context, access$MethodEntity);
return new RefineAccess$MethodVisitor(context, access$MethodEntity);
}
return mv;
}

static class RefineAccess$MethodVisitor extends MethodVisitor {

private List<AbstractInsnNode> instructions = new ArrayList<>();
private static class RefineAccess$MethodVisitor extends MethodNode {
private Access$MethodEntity access$MethodEntity;
private Context context;

public RefineAccess$MethodVisitor(MethodVisitor mv, Context context, Access$MethodEntity access$MethodEntity) {
super(Opcodes.ASM5, mv);
public RefineAccess$MethodVisitor(Context context, Access$MethodEntity access$MethodEntity) {
super(Opcodes.ASM5);
this.access$MethodEntity = access$MethodEntity;
this.context = context;
}


@Override
public void visitInsn(final int opcode) {
super.visitInsn(opcode);
instructions.add(new InsnNode(opcode));
}

@Override
public void visitIntInsn(final int opcode, final int operand) {
super.visitIntInsn(opcode, operand);
instructions.add(new IntInsnNode(opcode, operand));
}

@Override
public void visitVarInsn(final int opcode, final int var) {
super.visitVarInsn(opcode, var);
instructions.add(new VarInsnNode(opcode, var));
}

@Override
public void visitTypeInsn(final int opcode, final String type) {
super.visitTypeInsn(opcode, type);
instructions.add(new TypeInsnNode(opcode, type));
}

@Override
public void visitFieldInsn(final int opcode, final String owner,
final String name, final String desc) {
super.visitFieldInsn(opcode, owner, name, desc);
instructions.add(new FieldInsnNode(opcode, owner, name, desc));
}

@Deprecated
@Override
public void visitMethodInsn(int opcode, String owner, String name,
String desc) {
if (api >= Opcodes.ASM5) {
super.visitMethodInsn(opcode, owner, name, desc);
return;
}
super.visitMethodInsn(opcode, owner, name, desc);
instructions.add(new MethodInsnNode(opcode, owner, name, desc));
}

@Override
public void visitMethodInsn(int opcode, String owner, String name,
String desc, boolean itf) {
if (api < Opcodes.ASM5) {
super.visitMethodInsn(opcode, owner, name, desc, itf);
return;
}
super.visitMethodInsn(opcode, owner, name, desc, itf);
instructions.add(new MethodInsnNode(opcode, owner, name, desc, itf));
}

@Override
public void visitInvokeDynamicInsn(String name, String desc, Handle bsm,
Object... bsmArgs) {
super.visitInvokeDynamicInsn(name, desc, bsm, bsmArgs);
instructions.add(new InvokeDynamicInsnNode(name, desc, bsm, bsmArgs));
}

@Override
public void visitJumpInsn(final int opcode, final Label label) {
super.visitJumpInsn(opcode, label);
instructions.add(new JumpInsnNode(opcode, getLabelNode(label)));
}

@Override
public void visitLabel(final Label label) {
super.visitLabel(label);
instructions.add(getLabelNode(label));
}

@Override
public void visitLdcInsn(final Object cst) {
super.visitLdcInsn(cst);
instructions.add(new LdcInsnNode(cst));
}

@Override
public void visitIincInsn(final int var, final int increment) {
super.visitIincInsn(var, increment);
instructions.add(new IincInsnNode(var, increment));
}

@Override
public void visitTableSwitchInsn(final int min, final int max,
final Label dflt, final Label... labels) {
super.visitTableSwitchInsn(min, max, dflt, labels);
instructions.add(new TableSwitchInsnNode(min, max, getLabelNode(dflt),
getLabelNodes(labels)));
}

@Override
public void visitLookupSwitchInsn(final Label dflt, final int[] keys,
final Label[] labels) {
super.visitLookupSwitchInsn(dflt, keys, labels);
instructions.add(new LookupSwitchInsnNode(getLabelNode(dflt), keys,
getLabelNodes(labels)));
}

@Override
public void visitMultiANewArrayInsn(final String desc, final int dims) {
super.visitMultiANewArrayInsn(desc, dims);
instructions.add(new MultiANewArrayInsnNode(desc, dims));
}

protected LabelNode getLabelNode(final Label l) {
if (!(l.info instanceof LabelNode)) {
l.info = new LabelNode();
}
return (LabelNode) l.info;
}

private LabelNode[] getLabelNodes(final Label[] l) {
LabelNode[] nodes = new LabelNode[l.length];
for (int i = 0; i < l.length; ++i) {
nodes[i] = getLabelNode(l[i]);
}
return nodes;
}

private Object[] getLabelNodes(final Object[] objs) {
Object[] nodes = new Object[objs.length];
for (int i = 0; i < objs.length; ++i) {
Object o = objs[i];
if (o instanceof Label) {
o = getLabelNode((Label) o);
}
nodes[i] = o;
}
return nodes;
}

@Override
public void visitEnd() {
super.visitEnd();
Expand All @@ -220,13 +72,18 @@ public void visitEnd() {
}
}

private List<AbstractInsnNode> refine(List<AbstractInsnNode> instructions) {
private List<AbstractInsnNode> refine(InsnList instructions) {
List<AbstractInsnNode> refinedInsns = new ArrayList<>();
if (instructions == null) {
return refinedInsns;
}
ListIterator<AbstractInsnNode> insnNodeListIterator = instructions.iterator();
boolean shouldSkipVarInsn = true;
int varLoadInsnCount = 0;
MemberEntity target = null;
try {
for (AbstractInsnNode insnNode : instructions) {
while (insnNodeListIterator.hasNext()) {
AbstractInsnNode insnNode = insnNodeListIterator.next();
if (insnNode.getType() == AbstractInsnNode.LINE) continue;
if (insnNode.getType() == AbstractInsnNode.LABEL) continue;
if (insnNode.getOpcode() >= Opcodes.IRETURN && insnNode.getOpcode() <= Opcodes.RETURN)
Expand All @@ -246,6 +103,7 @@ private List<AbstractInsnNode> refine(List<AbstractInsnNode> instructions) {
if (insnNode.getOpcode() > Opcodes.MONITOREXIT) {
throw new ShouldSkipInlineException("Unexpected new instruction in access$ method body.");
}

if (shouldSkipVarInsn && insnNode.getOpcode() >= Opcodes.ILOAD && insnNode.getOpcode() <= Opcodes.SALOAD) {
varLoadInsnCount++;
continue;
Expand All @@ -266,13 +124,13 @@ private List<AbstractInsnNode> refine(List<AbstractInsnNode> instructions) {
case Opcodes.INVOKESPECIAL:
case Opcodes.INVOKEINTERFACE:
if (parameterCountOfTargetMethod != parameterCountOfAccess$Method - 1
|| varLoadInsnCount != parameterCountOfAccess$Method) {
|| varLoadInsnCount != parameterCountOfAccess$Method) {
throw new ShouldSkipInlineException("The parameter count of access$ method is abnormal.");
}
break;
case Opcodes.INVOKESTATIC:
if (parameterCountOfTargetMethod != parameterCountOfAccess$Method ||
varLoadInsnCount != parameterCountOfAccess$Method) {
varLoadInsnCount != parameterCountOfAccess$Method) {
throw new ShouldSkipInlineException("The parameter count of access$ method is abnormal.");
}
break;
Expand All @@ -291,7 +149,7 @@ private List<AbstractInsnNode> refine(List<AbstractInsnNode> instructions) {
switch (insnNode.getOpcode()) {
case Opcodes.GETSTATIC:
if (parameterCountOfAccess$Method != 0
|| varLoadInsnCount != parameterCountOfAccess$Method) {
|| varLoadInsnCount != parameterCountOfAccess$Method) {
throw new ShouldSkipInlineException("The parameter count of access$ method is abnormal.");
}
break;
Expand Down Expand Up @@ -331,7 +189,25 @@ private List<AbstractInsnNode> refine(List<AbstractInsnNode> instructions) {
}
refinedInsns.clear();
}

/**
* 没有找到target时，导致使用target时候NPE问题
* 清除需要内联的指令
*
* 例如：
* 遇到只有LDC指令的access$方法， 无法给access$MethodEntity 设置target
*
*/
if (target == null) {
refinedInsns.clear();
if (access$MethodEntity != null) {
context.getLogger().d("SkipInlineAccess", String.format("Skip inline access to %s (owner = [%s], name = [%s], desc = [%s]), for the reason that %s",
access$MethodEntity.className(), access$MethodEntity.name(), access$MethodEntity.desc(), "target is null"));
}
}

return refinedInsns;
}
}

}