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Merged
merged 4 commits into from
Aug 14, 2025
Merged

Improve decompiling fields #482

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f5160a4
Clean up field writing to reduce redundancies
sschr15 Jun 19, 2025
36c4b3b
Add line numbers to field declarations when feasible
sschr15 Jun 19, 2025
0eb8a9f
Port changes to Kotlin plugin
sschr15 Jun 19, 2025
b53c1b8
Revert failing tests
sschr15 Jun 19, 2025
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128 changes: 59 additions & 69 deletions plugins/kotlin/src/main/java/org/vineflower/kotlin/KotlinWriter.java
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Original file line number Diff line number Diff line change
Expand Up @@ -274,9 +274,6 @@ public void writeClass(ClassNode node, TextBuffer buffer, int indent) {
TextBuffer innerBuffer = new TextBuffer();

boolean hasContent = false;
boolean enumFields = false;

List<StructRecordComponent> components = cl.getRecordComponents();

Set<StructField> fieldsToIgnore = new HashSet<>();
Set<StructMethod> methodsToIgnore = new HashSet<>();
Expand Down Expand Up @@ -315,71 +312,37 @@ public void writeClass(ClassNode node, TextBuffer buffer, int indent) {
methodsToIgnore.addAll(companionFunctions.keySet());
}

// FIXME: fields don't have line mappings
// fields
List<StructRecordComponent> components = cl.getRecordComponents();

// Find the last field marked as an enum
int maxEnumIdx = 0;
for (int i = 0; i < cl.getFields().size(); i++) {
StructField fd = cl.getFields().get(i);
boolean isEnum = fd.hasModifier(CodeConstants.ACC_ENUM) && DecompilerContext.getOption(IFernflowerPreferences.DECOMPILE_ENUM);
if (isEnum) {
maxEnumIdx = i;
}
}

List<StructField> deferredEnumFields = new ArrayList<>();
List<StructField> enumFields = new ArrayList<>();
List<StructField> nonEnumFields = new ArrayList<>();

// Find any regular fields mixed in with the enum fields
// This is invalid but allowed in bytecode.
for (int i = 0; i < cl.getFields().size(); i++) {
StructField fd = cl.getFields().get(i);
for (StructField fd : cl.getFields()) {
boolean isEnum = fd.hasModifier(CodeConstants.ACC_ENUM) && DecompilerContext.getOption(IFernflowerPreferences.DECOMPILE_ENUM);
if (i < maxEnumIdx && !isEnum) {
deferredEnumFields.add(fd);
if (isEnum) {
enumFields.add(fd);
} else if (!fieldsToIgnore.contains(fd)) {
nonEnumFields.add(fd);
}
}

for (StructField fd : cl.getFields()) {
boolean hide = fd.isSynthetic() && DecompilerContext.getOption(IFernflowerPreferences.REMOVE_SYNTHETIC) ||
wrapper.getHiddenMembers().contains(InterpreterUtil.makeUniqueKey(fd.getName(), fd.getDescriptor())) ||
deferredEnumFields.contains(fd) ||
fieldsToIgnore.contains(fd);
if (hide) continue;

if (components != null && fd.getAccessFlags() == (CodeConstants.ACC_FINAL | CodeConstants.ACC_PRIVATE) &&
components.stream().anyMatch(c -> c.getName().equals(fd.getName()) && c.getDescriptor().equals(fd.getDescriptor()))) {
// Record component field: skip it
continue;
boolean enums = false;
for (StructField fd : enumFields) {
if (enums) {
innerBuffer.append(',').appendLineSeparator();
}
enums = true;

boolean isEnum = fd.hasModifier(CodeConstants.ACC_ENUM) && DecompilerContext.getOption(IFernflowerPreferences.DECOMPILE_ENUM);
if (isEnum) {
if (enumFields) {
innerBuffer.append(',').appendLineSeparator();
}
enumFields = true;
} else if (enumFields) {
innerBuffer.append(';');
innerBuffer.appendLineSeparator();
innerBuffer.appendLineSeparator();
enumFields = false;
}

if (propertyData == null || enumFields) { // Enum fields are not considered Kotlin properties
TextBuffer fieldBuffer = new TextBuffer();
writeField(wrapper, cl, fd, fieldBuffer, indent + 1);
fieldBuffer.clearUnassignedBytecodeMappingData();
innerBuffer.append(fieldBuffer);
writeField(innerBuffer, indent, fd, wrapper);
hasContent = true;
}

hasContent = true;
}
if (enums) {
innerBuffer.append(';').appendLineSeparator();
}

if (propertyData != null) {
// Any deferred fields that are property fields should be removed to prevent duplication
deferredEnumFields.removeAll(propertyData.associatedFields());

boolean addedLineAtEnd = false;
for (KProperty prop : propertyData.properties()) {
if (hasContent) {
Expand All @@ -394,7 +357,14 @@ public void writeClass(ClassNode node, TextBuffer buffer, int indent) {
innerBuffer.appendLineSeparator();
}

innerBuffer.append(propBuffer);
StructField fd = prop.underlyingField();
if (fd != null) {
nonEnumFields.remove(fd);
String initializer = fd.hasModifier(CodeConstants.ACC_STATIC) ? "<clinit> ()V" : "<init> ()V";
innerBuffer.append(propBuffer, cl.qualifiedName, initializer);
} else {
innerBuffer.append(propBuffer);
}

if (isMultiline) {
innerBuffer.appendLineSeparator();
Expand All @@ -407,14 +377,25 @@ public void writeClass(ClassNode node, TextBuffer buffer, int indent) {
if (!addedLineAtEnd && !propertyData.properties().isEmpty()) {
innerBuffer.appendLineSeparator();
}
}
} else {
for (StructField fd : nonEnumFields) {
boolean hide = fd.isSynthetic() && DecompilerContext.getOption(IFernflowerPreferences.REMOVE_SYNTHETIC) ||
wrapper.getHiddenMembers().contains(InterpreterUtil.makeUniqueKey(fd.getName(), fd.getDescriptor()));
if (hide) continue;

// If any fields remaining were deferred but not enum fields, re-add them
for (StructField fd2 : deferredEnumFields) {
TextBuffer fieldBuffer = new TextBuffer();
writeField(wrapper, cl, fd2, fieldBuffer, indent + 1);
fieldBuffer.clearUnassignedBytecodeMappingData();
innerBuffer.append(fieldBuffer);
if (components != null && fd.getAccessFlags() == (CodeConstants.ACC_FINAL | CodeConstants.ACC_PRIVATE) &&
components.stream().anyMatch(c -> c.getName().equals(fd.getName()) && c.getDescriptor().equals(fd.getDescriptor()))) {
// Record component field: skip it
continue;
}

DecompilerContext.getLogger().writeMessage("Non-enum field " + fd.getName() + " is not associated with Kotlin property", IFernflowerLogger.Severity.WARN);

TextBuffer fieldBuffer = new TextBuffer();
writeField(wrapper, wrapper.getClassStruct(), fd, fieldBuffer, indent + 1);
String initializer = fd.hasModifier(CodeConstants.ACC_STATIC) ? "<clinit> ()V" : "<init> ()V";
innerBuffer.append(fieldBuffer, wrapper.getClassStruct().qualifiedName, initializer);
}
}

// methods
Expand Down Expand Up @@ -526,7 +507,13 @@ private void writeKotlinFile(ClassNode node, TextBuffer buffer, int indent, KPro
buffer.appendLineSeparator();
}

buffer.append(propBuffer);
StructField fd = prop.underlyingField();
if (fd != null) {
String initializer = fd.hasModifier(CodeConstants.ACC_STATIC) ? "<clinit> ()V" : "<init> ()V";
buffer.append(propBuffer, cl.qualifiedName, initializer);
} else {
buffer.append(propBuffer);
}

if (isMultiline) {
buffer.appendLineSeparator();
Expand All @@ -543,11 +530,7 @@ private void writeKotlinFile(ClassNode node, TextBuffer buffer, int indent, KPro

for (StructField fd : cl.getFields()) {
if (propertyData.associatedFields().contains(fd)) continue;

TextBuffer fieldBuffer = new TextBuffer();
writeField(wrapper, cl, fd, fieldBuffer, indent);
fieldBuffer.clearUnassignedBytecodeMappingData();
buffer.append(fieldBuffer);
writeField(buffer, indent, fd, wrapper);
}

for (int i = 0; i < cl.getMethods().size(); i++) {
Expand Down Expand Up @@ -827,6 +810,13 @@ private void writeClassDefinition(ClassNode node, TextBuffer buffer, int indent,
buffer.popNewlineGroup();
}

private void writeField(TextBuffer buffer, int indent, StructField fd, ClassWrapper wrapper) {
TextBuffer fieldBuffer = new TextBuffer();
writeField(wrapper, wrapper.getClassStruct(), fd, fieldBuffer, indent + 1);
String initializer = fd.hasModifier(CodeConstants.ACC_STATIC) ? "<clinit> ()V" : "<init> ()V";
buffer.append(fieldBuffer, wrapper.getClassStruct().qualifiedName, initializer);
}

public void writeField(ClassWrapper wrapper, StructClass cl, StructField fd, TextBuffer buffer, int indent) {
boolean isInterface = cl.hasModifier(CodeConstants.ACC_INTERFACE);
boolean isDeprecated = fd.hasAttribute(StructGeneralAttribute.ATTRIBUTE_DEPRECATED);
Expand Down
2 changes: 1 addition & 1 deletion plugins/kotlin/src/main/java/org/vineflower/kotlin/struct/KProperty.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -99,7 +99,7 @@ public TextBuffer stringify(int indent) {

if (initializer != null) {
TextBuffer initializerBuf = initializer.toJava(indent);
initializerBuf.clearUnassignedBytecodeMappingData();
// initializerBuf.clearUnassignedBytecodeMappingData();
if (flags.isDelegated) {
buf.append(" by ")
.append(initializerBuf);
Expand Down
9 changes: 8 additions & 1 deletion plugins/kotlin/testData/results/pkg/TestClassicStringInterpolation.dec
View file
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Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
package pkg

public class TestClassicStringInterpolation {
public final val x: Int = 5
public final val x: Int = 5// 16

public fun stringInterpolation(x: Int, y: String) {
System.out.println("$x $y");// 5
Expand All @@ -25,6 +25,10 @@ public class TestClassicStringInterpolation {
}

class 'pkg/TestClassicStringInterpolation' {
method '<init> ()V' {
5 3
}

method 'stringInterpolation (ILjava/lang/String;)V' {
d 6
16 6
Expand Down Expand Up @@ -111,7 +115,10 @@ Lines mapping:
10 <-> 12
13 <-> 15
14 <-> 16
16 <-> 4
18 <-> 19
19 <-> 20
22 <-> 23
23 <-> 24
Not mapped:
3
49 changes: 46 additions & 3 deletions plugins/kotlin/testData/results/pkg/TestConvertedK2JOps.dec
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Original file line number Diff line number Diff line change
@@ -1,9 +1,9 @@
package pkg

public class TestConvertedK2JOps {
public final val list: List<String> = CollectionsKt.listOf(new java.lang.String[]{"a", "b", "c"})
public final val set: Set<String> = SetsKt.setOf(new java.lang.String[]{"a", "b", "c"})
public final val map: Map<String, String> = MapsKt.mapOf(new Pair[]{TuplesKt.to("a", "b"), TuplesKt.to("c", "d")})
public final val list: List<String> = CollectionsKt.listOf(new java.lang.String[]{"a", "b", "c"})// 4
public final val set: Set<String> = SetsKt.setOf(new java.lang.String[]{"a", "b", "c"})// 5
public final val map: Map<String, String> = MapsKt.mapOf(new Pair[]{TuplesKt.to("a", "b"), TuplesKt.to("c", "d")})// 6
public final val any: Any = new Object()

public fun codeConstructs() {
Expand All @@ -12,6 +12,44 @@ public class TestConvertedK2JOps {
}

class 'pkg/TestConvertedK2JOps' {
method '<init> ()V' {
c 3
d 3
11 3
12 3
16 3
17 3
1a 3
1b 3
1c 3
28 4
29 4
2d 4
2e 4
32 4
33 4
36 4
37 4
38 4
44 5
45 5
46 5
47 5
48 5
49 5
4a 5
4e 5
4f 5
50 5
51 5
52 5
53 5
54 5
57 5
58 5
59 5
}

method 'codeConstructs ()V' {
0 9
1 9
Expand All @@ -26,7 +64,12 @@ class 'pkg/TestConvertedK2JOps' {
}

Lines mapping:
4 <-> 4
5 <-> 5
6 <-> 6
10 <-> 10
12 <-> 11
Not mapped:
3
7
11
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