Support Gradle alongside SSJB

This makes builds faster, simpler and better automated but still keeps
Cuchaz happy. :)

1 files changed, 123 insertions, 0 deletions

diff --git a/src/cuchaz/enigma/bytecode/LocalVariableRenamer.java b/src/cuchaz/enigma/bytecode/LocalVariableRenamer.java
new file mode 100644
index 0000000..ae0455f
--- /dev/null
+++ b/src/cuchaz/enigma/bytecode/LocalVariableRenamer.java
@@ -0,0 +1,123 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Jeff Martin.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Lesser General Public
+ * License v3.0 which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/lgpl.html
+ * 
+ * Contributors:
+ *     Jeff Martin - initial API and implementation
+ ******************************************************************************/
+package cuchaz.enigma.bytecode;
+
+import javassist.CtBehavior;
+import javassist.CtClass;
+import javassist.bytecode.ByteArray;
+import javassist.bytecode.CodeAttribute;
+import javassist.bytecode.ConstPool;
+import javassist.bytecode.LocalVariableAttribute;
+import javassist.bytecode.LocalVariableTypeAttribute;
+import cuchaz.enigma.mapping.ArgumentEntry;
+import cuchaz.enigma.mapping.BehaviorEntry;
+import cuchaz.enigma.mapping.EntryFactory;
+import cuchaz.enigma.mapping.Translator;
+
+
+public class LocalVariableRenamer {
+        
+        private Translator m_translator;
+        
+        public LocalVariableRenamer(Translator translator) {
+                m_translator = translator;
+        }
+
+        public void rename(CtClass c) {
+                for (CtBehavior behavior : c.getDeclaredBehaviors()) {
+                        
+                        // if there's a local variable table, just rename everything to v1, v2, v3, ... for now
+                        CodeAttribute codeAttribute = behavior.getMethodInfo().getCodeAttribute();
+                        if (codeAttribute == null) {
+                                continue;
+                        }
+                        
+                        BehaviorEntry behaviorEntry = EntryFactory.getBehaviorEntry(behavior);
+                        ConstPool constants = c.getClassFile().getConstPool();
+                        
+                        LocalVariableAttribute table = (LocalVariableAttribute)codeAttribute.getAttribute(LocalVariableAttribute.tag);
+                        if (table != null) {
+                                renameLVT(behaviorEntry, constants, table);
+                        }
+                        
+                        LocalVariableTypeAttribute typeTable = (LocalVariableTypeAttribute)codeAttribute.getAttribute(LocalVariableAttribute.typeTag);
+                        if (typeTable != null) {
+                                renameLVTT(typeTable, table);
+                        }
+                }
+        }
+
+        // DEBUG
+        @SuppressWarnings("unused")
+        private void dumpTable(LocalVariableAttribute table) {
+                for (int i=0; i<table.tableLength(); i++) {
+                        System.out.println(String.format("\t%d (%d): %s %s",
+                                i, table.index(i), table.variableName(i), table.descriptor(i)
+                        ));
+                }
+        }
+
+        private void renameLVT(BehaviorEntry behaviorEntry, ConstPool constants, LocalVariableAttribute table) {
+                
+                // skip empty tables
+                if (table.tableLength() <= 0) {
+                        return;
+                }
+                
+                // where do we start counting variables?
+                int starti = 0;
+                if (table.variableName(0).equals("this")) {
+                        // skip the "this" variable
+                        starti = 1;
+                }
+                
+                // rename method arguments first
+                int numArgs = 0;
+                if (behaviorEntry.getSignature() != null) {
+                        numArgs = behaviorEntry.getSignature().getArgumentTypes().size();
+                        for (int i=starti; i<starti + numArgs && i<table.tableLength(); i++) {
+                                int argi = i - starti;
+                                String argName = m_translator.translate(new ArgumentEntry(behaviorEntry, argi, ""));
+                                if (argName == null) {
+                                        argName = "a" + (argi + 1);
+                                }
+                                renameVariable(table, i, constants.addUtf8Info(argName));
+                        }
+                }
+                
+                // then rename the rest of the args, if any
+                for (int i=starti + numArgs; i<table.tableLength(); i++) {
+                        int firstIndex = table.index(starti + numArgs);
+                        renameVariable(table, i, constants.addUtf8Info("v" + (table.index(i) - firstIndex + 1)));
+                }
+        }
+        
+        private void renameLVTT(LocalVariableTypeAttribute typeTable, LocalVariableAttribute table) {
+                // rename args to the same names as in the LVT
+                for (int i=0; i<typeTable.tableLength(); i++) {
+                        renameVariable(typeTable, i, getNameIndex(table, typeTable.index(i)));
+                }
+        }
+
+        private void renameVariable(LocalVariableAttribute table, int i, int stringId) {
+                // based off of LocalVariableAttribute.nameIndex()
+                ByteArray.write16bit(stringId, table.get(), i*10 + 6);
+        }
+        
+        private int getNameIndex(LocalVariableAttribute table, int index) {
+                for (int i=0; i<table.tableLength(); i++) {
+                        if (table.index(i) == index) {
+                                return table.nameIndex(i);
+                        }
+                }
+                return 0;
+        }
+}