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fix: don't inline 'null' object to make code compilable (#964)

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This commit is contained in:
Skylot
2020-08-10 20:42:11 +01:00
parent 444ea9ec7e
commit 545cd4ec12
5 changed files with 115 additions and 47 deletions
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jadx-core/src/main/java/jadx/core/dex/attributes/AFlag.java
+1
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@@ -15,6 +15,7 @@ public enum AFlag {
DONT_WRAP,
DONT_INLINE,
DONT_INLINE_CONST,
DONT_GENERATE, // process as usual, but don't output to generated code
COMMENT_OUT, // process as usual, but comment insn in generated code
REMOVE, // can be completely removed
jadx-core/src/main/java/jadx/core/dex/visitors/ConstInlineVisitor.java
+43 -45
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@@ -10,7 +10,6 @@ import jadx.core.dex.instructions.ConstStringNode;
import jadx.core.dex.instructions.IndexInsnNode;
import jadx.core.dex.instructions.InsnType;
import jadx.core.dex.instructions.InvokeNode;
import jadx.core.dex.instructions.InvokeType;
import jadx.core.dex.instructions.args.ArgType;
import jadx.core.dex.instructions.args.InsnArg;
import jadx.core.dex.instructions.args.LiteralArg;
@@ -73,17 +72,8 @@ public class ConstInlineVisitor extends AbstractVisitor {
return;
}
long lit = ((LiteralArg) constArg).getLiteral();
if (lit == 0 && checkObjectInline(sVar)) {
if (sVar.getUseCount() == 1) {
InsnNode assignInsn = insn.getResult().getAssignInsn();
if (assignInsn != null) {
assignInsn.add(AFlag.DONT_INLINE);
}
}
return;
}
// don't inline const values in synchronized statement
if (checkForSynchronizeBlock(insn, sVar)) {
if (lit == 0 && forbidNullInlines(sVar)) {
// all usages forbids inlining
return;
}
} else if (insnType == InsnType.CONST_STR) {
@@ -117,20 +107,6 @@ public class ConstInlineVisitor extends AbstractVisitor {
replaceConst(mth, insn, constArg, toRemove);
}
private static boolean checkForSynchronizeBlock(InsnNode insn, SSAVar ssaVar) {
for (RegisterArg reg : ssaVar.getUseList()) {
InsnNode parentInsn = reg.getParentInsn();
if (parentInsn != null) {
InsnType insnType = parentInsn.getType();
if (insnType == InsnType.MONITOR_ENTER || insnType == InsnType.MONITOR_EXIT) {
insn.add(AFlag.DONT_INLINE);
return true;
}
}
}
return false;
}
private static boolean checkForFinallyBlock(SSAVar sVar) {
List<SSAVar> ssaVars = sVar.getCodeVar().getSsaVars();
if (ssaVars.size() <= 1) {
@@ -153,37 +129,60 @@ public class ConstInlineVisitor extends AbstractVisitor {
}
/**
* Don't inline null object if:
* - used as instance arg in invoke instruction
* - used in 'array.length'
* Don't inline null object
*/
private static boolean checkObjectInline(SSAVar sVar) {
for (RegisterArg useArg : sVar.getUseList()) {
private static boolean forbidNullInlines(SSAVar sVar) {
List<RegisterArg> useList = sVar.getUseList();
if (useList.isEmpty()) {
return false;
}
int k = 0;
for (RegisterArg useArg : useList) {
InsnNode insn = useArg.getParentInsn();
if (insn == null) {
continue;
}
InsnType insnType = insn.getType();
if (insnType == InsnType.INVOKE) {
InvokeNode inv = (InvokeNode) insn;
if (inv.getInvokeType() != InvokeType.STATIC
&& inv.getArg(0) == useArg) {
return true;
}
} else if (insnType == InsnType.ARRAY_LENGTH) {
if (insn.getArg(0) == useArg) {
return true;
}
if (!canUseNull(insn, useArg)) {
useArg.add(AFlag.DONT_INLINE_CONST);
k++;
}
}
return false;
return k == useList.size();
}
private static int replaceConst(MethodNode mth, InsnNode constInsn, InsnArg constArg, List<InsnNode> toRemove) {
private static boolean canUseNull(InsnNode insn, RegisterArg useArg) {
switch (insn.getType()) {
case INVOKE:
return ((InvokeNode) insn).getInstanceArg() != useArg;
case ARRAY_LENGTH:
case AGET:
case APUT:
case IGET:
case SWITCH:
case MONITOR_ENTER:
case MONITOR_EXIT:
case INSTANCE_OF:
return insn.getArg(0) != useArg;
case IPUT:
return insn.getArg(1) != useArg;
}
return true;
}
private static void replaceConst(MethodNode mth, InsnNode constInsn, InsnArg constArg, List<InsnNode> toRemove) {
SSAVar ssaVar = constInsn.getResult().getSVar();
if (ssaVar.getUseCount() == 0) {
toRemove.add(constInsn);
return;
}
List<RegisterArg> useList = new ArrayList<>(ssaVar.getUseList());
int replaceCount = 0;
for (RegisterArg arg : useList) {
if (arg.contains(AFlag.DONT_INLINE_CONST)) {
continue;
}
if (replaceArg(mth, arg, constArg, constInsn, toRemove)) {
replaceCount++;
}
@@ -191,7 +190,6 @@ public class ConstInlineVisitor extends AbstractVisitor {
if (replaceCount == useList.size()) {
toRemove.add(constInsn);
}
return replaceCount;
}
private static boolean replaceArg(MethodNode mth, RegisterArg arg, InsnArg constArg, InsnNode constInsn, List<InsnNode> toRemove) {
jadx-core/src/main/java/jadx/core/dex/visitors/shrink/CodeShrinkVisitor.java
+5 -1
View File
@@ -93,10 +93,14 @@ public class CodeShrinkVisitor extends AbstractVisitor {
}
List<RegisterArg> useList = sVar.getUseList();
if (!useList.isEmpty()) {
InsnNode parentInsn = useList.get(0).getParentInsn();
RegisterArg useArg = useList.get(0);
InsnNode parentInsn = useArg.getParentInsn();
if (parentInsn != null && parentInsn.contains(AFlag.DONT_GENERATE)) {
return;
}
if (!assignInline && useArg.contains(AFlag.DONT_INLINE_CONST)) {
return;
}
}
int assignPos = insnList.getIndex(assignInsn);
jadx-core/src/main/java/jadx/core/utils/Utils.java
+1 -1
View File
@@ -58,7 +58,7 @@ public class Utils {
if (objects == null) {
return "";
}
return listToString(objects, joiner, Object::toString);
return listToString(objects, joiner, Objects::toString);
}
public static <T> String listToString(Iterable<T> objects, Function<T, String> toStr) {
jadx-core/src/test/java/jadx/tests/integration/others/TestWrongCode2.java
+65
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@@ -0,0 +1,65 @@
package jadx.tests.integration.others;
import org.junit.jupiter.api.Test;
import jadx.tests.api.IntegrationTest;
import static jadx.tests.api.utils.assertj.JadxAssertions.assertThat;
public class TestWrongCode2 extends IntegrationTest {
public static class TestCls {
@SuppressWarnings("ConstantConditions")
public String test() {
A a = null;
a.str = "";
return a.str;
}
@SuppressWarnings("ConstantConditions")
public int test2() {
int[] a = null;
a[1] = 2;
return a[0];
}
@SuppressWarnings({ "ConstantConditions", "SynchronizationOnLocalVariableOrMethodParameter" })
public boolean test3() {
A a = null;
synchronized (a) {
return true;
}
}
public boolean test4() {
return null instanceof A;
}
// everything is 'A' :)
@SuppressWarnings({ "MethodName", "LocalVariableName" }) // ignore checkstyle
public A A() {
A A = A();
A.A = A;
return A;
}
@SuppressWarnings("MemberName")
public static class A {
public String str;
public A A;
}
}
@Test
public void test() {
assertThat(getClassNode(TestCls.class))
.code()
.containsOne("return a.str;");
}
@Test
public void testNoDebug() {
noDebugInfo();
getClassNode(TestCls.class);
}
}