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fix: inline constants in chained move instructions (#399)

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This commit is contained in:
Skylot
2018-12-01 13:28:28 +03:00
parent 21e11c1d47
commit 95f9ab035d
4 changed files with 177 additions and 54 deletions
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jadx-core/src/main/java/jadx/core/dex/visitors/ConstInlineVisitor.java
+63 -54
View File
@@ -22,6 +22,7 @@ import jadx.core.dex.visitors.ssa.SSATransform;
import jadx.core.dex.visitors.typeinference.TypeInferenceVisitor;
import jadx.core.utils.InstructionRemover;
import jadx.core.utils.exceptions.JadxException;
import jadx.core.utils.exceptions.JadxOverflowException;
@JadxVisitor(
name = "Constants Inline",
@@ -40,21 +41,23 @@ public class ConstInlineVisitor extends AbstractVisitor {
for (BlockNode block : mth.getBasicBlocks()) {
toRemove.clear();
for (InsnNode insn : block.getInstructions()) {
if (checkInsn(mth, insn)) {
toRemove.add(insn);
}
checkInsn(mth, insn, toRemove);
}
InstructionRemover.removeAll(mth, block, toRemove);
}
}
private static boolean checkInsn(MethodNode mth, InsnNode insn) {
if (insn.getType() != InsnType.CONST || insn.contains(AFlag.DONT_INLINE)) {
return false;
private static void checkInsn(MethodNode mth, InsnNode insn, List<InsnNode> toRemove) {
if (insn.contains(AFlag.DONT_INLINE)) {
return;
}
InsnType insnType = insn.getType();
if (insnType != InsnType.CONST && insnType != InsnType.MOVE) {
return;
}
InsnArg arg = insn.getArg(0);
if (!arg.isLiteral()) {
return false;
return;
}
long lit = ((LiteralArg) arg).getLiteral();
@@ -66,9 +69,9 @@ public class ConstInlineVisitor extends AbstractVisitor {
assignInsn.add(AFlag.DONT_INLINE);
}
}
return false;
return;
}
return replaceConst(mth, insn, lit);
replaceConst(mth, insn, lit, toRemove);
}
/**
@@ -98,54 +101,60 @@ public class ConstInlineVisitor extends AbstractVisitor {
return false;
}
private static boolean replaceConst(MethodNode mth, InsnNode constInsn, long literal) {
SSAVar sVar = constInsn.getResult().getSVar();
List<RegisterArg> use = new ArrayList<>(sVar.getUseList());
private static void replaceConst(MethodNode mth, InsnNode constInsn, long literal, List<InsnNode> toRemove) {
SSAVar ssaVar = constInsn.getResult().getSVar();
List<RegisterArg> useList = new ArrayList<>(ssaVar.getUseList());
int replaceCount = 0;
for (RegisterArg arg : use) {
InsnNode useInsn = arg.getParentInsn();
if (useInsn == null
|| useInsn.getType() == InsnType.PHI
|| useInsn.getType() == InsnType.MERGE
) {
continue;
}
LiteralArg litArg;
ArgType argType = arg.getType();
if (argType.isObject() && literal != 0) {
argType = ArgType.NARROW_NUMBERS;
}
if (use.size() == 1 || arg.isTypeImmutable()) {
// arg used only in one place
litArg = InsnArg.lit(literal, argType);
} else if (useInsn.getType() == InsnType.MOVE
&& !useInsn.getResult().getType().isTypeKnown()) {
// save type for 'move' instructions (hard to find type in chains of 'move')
litArg = InsnArg.lit(literal, argType);
} else {
// in most cases type not equal arg.getType()
// just set unknown type and run type fixer
litArg = InsnArg.lit(literal, ArgType.UNKNOWN);
}
if (useInsn.replaceArg(arg, litArg)) {
litArg.setType(arg.getInitType());
for (RegisterArg arg : useList) {
if (replaceArg(mth, arg, literal, constInsn, toRemove)) {
replaceCount++;
if (useInsn.getType() == InsnType.RETURN) {
useInsn.setSourceLine(constInsn.getSourceLine());
}
FieldNode f = null;
ArgType litArgType = litArg.getType();
if (litArgType.isTypeKnown()) {
f = mth.getParentClass().getConstFieldByLiteralArg(litArg);
} else if (litArgType.contains(PrimitiveType.INT)) {
f = mth.getParentClass().getConstField((int) literal, false);
}
if (f != null) {
litArg.wrapInstruction(new IndexInsnNode(InsnType.SGET, f.getFieldInfo(), 0));
}
}
}
return replaceCount == use.size();
if (replaceCount == useList.size()) {
toRemove.add(constInsn);
}
}
private static boolean replaceArg(MethodNode mth, RegisterArg arg, long literal, InsnNode constInsn, List<InsnNode> toRemove) {
InsnNode useInsn = arg.getParentInsn();
if (useInsn == null) {
return false;
}
InsnType insnType = useInsn.getType();
if (insnType == InsnType.PHI || insnType == InsnType.MERGE) {
return false;
}
ArgType argType = arg.getInitType();
if (argType.isObject() && literal != 0) {
argType = ArgType.NARROW_NUMBERS;
}
LiteralArg litArg = InsnArg.lit(literal, argType);
if (!useInsn.replaceArg(arg, litArg)) {
return false;
}
// arg replaced, made some optimizations
litArg.setType(arg.getInitType());
FieldNode fieldNode = null;
ArgType litArgType = litArg.getType();
if (litArgType.isTypeKnown()) {
fieldNode = mth.getParentClass().getConstFieldByLiteralArg(litArg);
} else if (litArgType.contains(PrimitiveType.INT)) {
fieldNode = mth.getParentClass().getConstField((int) literal, false);
}
if (fieldNode != null) {
litArg.wrapInstruction(new IndexInsnNode(InsnType.SGET, fieldNode.getFieldInfo(), 0));
}
if (insnType == InsnType.RETURN) {
useInsn.setSourceLine(constInsn.getSourceLine());
} else if (insnType == InsnType.MOVE) {
try {
replaceConst(mth, useInsn, literal, toRemove);
} catch (StackOverflowError e) {
throw new JadxOverflowException("Stack overflow at const inline visitor");
}
}
return true;
}
}
jadx-core/src/test/java/jadx/tests/api/SmaliTest.java
+4
View File
@@ -24,6 +24,10 @@ public abstract class SmaliTest extends IntegrationTest {
return getClassNodeFromSmali(path + File.separatorChar + clsName, clsName);
}
protected ClassNode getClassNodeFromSmaliWithPkg(String pkg, String clsName) {
return getClassNodeFromSmali(pkg + File.separatorChar + clsName, pkg + '.' + clsName);
}
protected ClassNode getClassNodeFromSmali(String clsName) {
return getClassNodeFromSmali(clsName, clsName);
}
jadx-core/src/test/java/jadx/tests/integration/types/TestConstInline.java
+38
View File
@@ -0,0 +1,38 @@
package jadx.tests.integration.types;
import org.junit.Test;
import jadx.core.dex.nodes.ClassNode;
import jadx.tests.api.SmaliTest;
import static jadx.tests.api.utils.JadxMatchers.containsOne;
import static org.junit.Assert.assertThat;
public class TestConstInline extends SmaliTest {
// private static String test(boolean b) {
// List<String> list;
// String str;
// if (b) {
// list = Collections.emptyList();
// str = "1";
// } else {
// list = null;
// str = list; // not correct assign in java but bytecode allow it
// }
// return use(list, str);
// }
//
// private static String use(List<String> list, String str) {
// return list + str;
// }
@Test
public void test() {
ClassNode cls = getClassNodeFromSmaliWithPkg("types", "TestConstInline");
String code = cls.getCode().toString();
assertThat(code, containsOne("list = null;"));
assertThat(code, containsOne("str = null;"));
}
}
jadx-core/src/test/smali/types/TestConstInline.smali
+72
View File
@@ -0,0 +1,72 @@
.class public Ltypes/TestConstInline;
.super Ljava/lang/Object;
.method private static test(Z)Ljava/lang/String;
.registers 4
.param p0, "b" # Z
if-eqz p0, :cond_d
invoke-static {}, Ltypes/TestConstInline;->list()Ljava/util/List;
move-result-object v0
const-string v1, "1"
goto :goto_return
:cond_d
const/4 v2, 0x0
# chained move instead zero const loading
move v0, v2
move v1, v0
goto :goto_return
:goto_return
invoke-static {v0, v1}, Ltypes/TestConstInline;->use(Ljava/util/List;Ljava/lang/String;)Ljava/lang/String;
move-result-object v2
return-object v2
.end method
.method private static use(Ljava/util/List;Ljava/lang/String;)Ljava/lang/String;
.registers 3
.annotation system Ldalvik/annotation/Signature;
value = {
"(",
"Ljava/util/List",
"<",
"Ljava/lang/String;",
">;",
"Ljava/lang/String;",
")",
"Ljava/lang/String;"
}
.end annotation
new-instance v0, Ljava/lang/StringBuilder;
invoke-direct {v0}, Ljava/lang/StringBuilder;-><init>()V
invoke-virtual {v0, p0}, Ljava/lang/StringBuilder;->append(Ljava/lang/Object;)Ljava/lang/StringBuilder;
move-result-object v0
invoke-virtual {v0, p1}, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder;
move-result-object v0
invoke-virtual {v0}, Ljava/lang/StringBuilder;->toString()Ljava/lang/String;
move-result-object v0
return-object v0
.end method
.method private static list()Ljava/util/List;
.registers 1
.annotation system Ldalvik/annotation/Signature;
value = {
"()",
"Ljava/util/List",
"<",
"Ljava/lang/String;",
">;"
}
.end annotation
invoke-static {}, Ljava/util/Collections;->emptyList()Ljava/util/List;
move-result-object v0
return-object v0
.end method