Add automatic renaming feature

src/main/java/org/dimdev/javaremapper/CommandLine.java

@@ -2,10 +2,12 @@
 
 import org.dimdev.srg2jam.Srg2Jam;
 
-import java.io.File;
-import java.io.FileReader;
-import java.io.IOException;
-import java.io.Reader;
+import java.io.*;
+import java.util.Enumeration;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
 
 public final class CommandLine {
     public static void main(String... args) throws IOException {
@@ -15,6 +17,7 @@ public static void main(String... args) throws IOException {
             System.out.println();
             System.out.println("Subcommands:");
             System.out.println(" remap <jar> <target> <mappings> - Remaps a jar file using a JAM mapping file");
+            System.out.println(" rename <jar> <target> <mappings> - Generates mappings with unique identifiers for everything");
             System.out.println(" srg2jam <path to MCP config folder> - Converts a MCP config folder to a JAM file");
             System.out.println(" help - Displays this help message");
             return;
@@ -37,6 +40,36 @@ public static void main(String... args) throws IOException {
                 break;
             }
 
+            case "rename" : {
+                File inputFile = new File(args[1]);
+                File remapTarget = new File(args[2]);
+                File mappingTarget = new File(args[3]);
+
+                if (remapTarget.exists()) remapTarget.delete();
+                if (mappingTarget.exists()) mappingTarget.delete();
+
+                Set<String> classesInJar = new HashSet<>();
+                try (JarFile jar = new JarFile(inputFile)) {
+                    Enumeration<JarEntry> entries = jar.entries();
+                    do {
+                        JarEntry entry = entries.nextElement();
+                        String name = entry.getName();
+                        if (name.endsWith(".class")) {
+                            String className = name.substring(0, name.length() - 6);
+                            classesInJar.add(className);
+                        }
+                    } while (entries.hasMoreElements());
+                }
+
+                InheritanceProvider inheritanceProvider = JavaRemapper.makeInheritanceProvider(inputFile);
+                Mapping mapping = new GeneratingMapping(inheritanceProvider, classesInJar);
+                new JavaRemapper(mapping).remapJar(inputFile, remapTarget);
+
+                mapping.writeToJAM(new FileWriter(mappingTarget));
+
+                break;
+            }
+
             case "srg2jam": {
                 Srg2Jam.convert(new File(args[1]));
                 break;

src/main/java/org/dimdev/javaremapper/GeneratingMapping.java

@@ -0,0 +1,66 @@
+package org.dimdev.javaremapper;
+
+import java.util.Set;
+
+public class GeneratingMapping extends Mapping {
+    private InheritanceProvider inheritanceProvider;
+    private Set<String> classFilter;
+    private int classIndex = 0;
+    private int fieldIndex = 0;
+    private int methodIndex = 0;
+
+    public GeneratingMapping(InheritanceProvider inheritanceProvider, Set<String> classFilter) {
+        this.inheritanceProvider = inheritanceProvider;
+        this.classFilter = classFilter;
+    }
+
+    public String getClass(String className) {
+        // Don't remap classes not in jar
+        if (!classFilter.contains(className)) return null;
+
+        String result = super.getClass(className);
+        if (result == null) {
+            result = "Class" + classIndex++;
+            addClass(className, result);
+        }
+        return result;
+    }
+
+    public String getField(String className, String fieldName, String fieldDescriptor) {
+        // Don't remap classes not in jar
+        if (!classFilter.contains(className)) return null;
+
+        // Don't remap inherited fields, their name is inherited from the parent's mapping
+        for (String superclass : inheritanceProvider.getAllSuperclasses(className)) {
+            if (inheritanceProvider.getInheritableFields(superclass).contains(new MemberRef(fieldName, fieldDescriptor))) {
+                return null;
+            }
+        }
+
+        String result = super.getField(className, fieldName, fieldDescriptor);
+        if (result == null) {
+            result = "field" + fieldIndex++;
+            addField(className, fieldName, fieldDescriptor, result);
+        }
+        return result;
+    }
+
+    public String getMethod(String className, String methodName, String methodDescriptor) {
+        // Don't remap classes not in jar
+        if (!classFilter.contains(className)) return null;
+
+        // Don't remap inherited methods, their name is inherited from the parent's mapping
+        for (String superclass : inheritanceProvider.getAllSuperclasses(className)) {
+            if (inheritanceProvider.getInheritableMethods(superclass).contains(new MemberRef(methodName, methodDescriptor))) {
+                return null;
+            }
+        }
+
+        String result = super.getField(className, methodName, methodDescriptor);
+        if (result == null) {
+            result = "method" + fieldIndex++;
+            addMethod(className, methodName, methodDescriptor, "method" + methodIndex++);
+        }
+        return result;
+    }
+}

src/main/java/org/dimdev/javaremapper/JavaRemapper.java

@@ -25,6 +25,10 @@ public JavaRemapper(Mapping mapping) {
     }
 
     public void remapJar(File inputFile, File remapTarget) throws IOException {
+        remapJar(inputFile, remapTarget, makeInheritanceProvider(inputFile));
+    }
+
+    public static InheritanceProvider makeInheritanceProvider(File inputFile) throws IOException {
         // Make the inheritance map
         InheritanceMapper inheritanceMapper = new InheritanceMapper();
         try (JarFile jar = new JarFile(inputFile)) {
@@ -40,9 +44,12 @@ public void remapJar(File inputFile, File remapTarget) throws IOException {
                 }
             }
         }
+        return inheritanceMapper;
+    }
 
+    public void remapJar(File inputFile, File remapTarget, InheritanceProvider inheritanceProvider) throws IOException {
         // Initialize the remapper using the mapping and inheritance provider
-        SimpleRemapper remapper = new SimpleRemapper(mapping, inheritanceMapper);
+        SimpleRemapper remapper = new SimpleRemapper(mapping, inheritanceProvider);
 
         // Copy jar classes, remapping them if necessary
         try (JarFile jar = new JarFile(inputFile);