support WASM

build.gradle

@@ -28,7 +28,7 @@ subprojects {
     apply plugin: 'java'
     //apply plugin: 'application'
 
-    sourceCompatibility = "1.8";
+    sourceCompatibility = "1.8"
     //mainClassName = 'com.github.zxh0.luago.Main'
 
     sourceCompatibility = '1.8'

classpy-common/src/main/java/com/github/zxh/classpy/common/FileComponent.java

@@ -55,6 +55,10 @@ protected final void add(String name, FileComponent subComponent) {
         components.add(subComponent);
     }
 
+    protected final void clear() {
+        components.clear();
+    }
+
     /**
      * The returned string will be displayed by BytesTreeItem.
      *

classpy-gui/src/main/java/com/github/zxh/classpy/gui/MyMenuBar.java

@@ -46,6 +46,7 @@ private Menu createOpenMenu() {
         openMenu.getItems().add(createOpenMenuItem(FileType.JAVA_JAR));
         openMenu.getItems().add(createOpenMenuItem(FileType.JAVA_CLASS));
         openMenu.getItems().add(createOpenMenuItem(FileType.LUA_BC));
+        openMenu.getItems().add(createOpenMenuItem(FileType.WASM));
         openMenu.setMnemonicParsing(true);
         return openMenu;
     }

classpy-gui/src/main/java/com/github/zxh/classpy/gui/support/FileType.java

@@ -11,6 +11,7 @@ public enum FileType {
     JAVA_JAR("/jar.png", "Java JAR", "*.jar"),
     JAVA_CLASS("/java.png", "Java Class", "*.class"),
     LUA_BC("/lua.png", "Lua Binary Chunk", "*.luac"),
+    WASM("/wasm.png", "WebAssembly Binary Code", "*.wasm"),
     UNKNOWN("/file.png", "Unknown", "*.*"),
     ;
 

classpy-gui/src/main/java/com/github/zxh/classpy/gui/support/FileTypeInferer.java

@@ -5,6 +5,7 @@
 
 public class FileTypeInferer {
 
+    private static final byte[] wasmMagicNumber = {0, 'a', 's', 'm'};
     private static final byte[] binaryChunkSig = {0x1B, 'L', 'u', 'a'};
     private static final byte[] classMagicNumber = {
             (byte) 0xCA,
@@ -24,6 +25,9 @@ public static FileType inferFileType(URL url) {
         if (filename.endsWith(".luac")) {
             return FileType.LUA_BC;
         }
+        if (filename.endsWith(".wasm")) {
+            return FileType.WASM;
+        }
         return FileType.UNKNOWN;
     }
 
@@ -36,6 +40,9 @@ public static FileType inferFileType(byte[] data) {
             if (Arrays.equals(magicNumber, binaryChunkSig)) {
                 return FileType.LUA_BC;
             }
+            if (Arrays.equals(magicNumber, wasmMagicNumber)) {
+                return FileType.WASM;
+            }
         }
         return FileType.UNKNOWN;
     }

classpy-gui/src/main/java/com/github/zxh/classpy/gui/support/OpenFileTask.java

@@ -12,6 +12,7 @@
 import java.net.URL;
 import java.util.function.Consumer;
 
+import com.github.zxh.classpy.wasm.WasmBinParser;
 import javafx.concurrent.Task;
 
 public class OpenFileTask extends Task<OpenFileResult> {
@@ -49,6 +50,7 @@ private static FileComponent parse(byte[] data, FileType fileType) {
         switch (fileType) {
             case JAVA_CLASS: return new ClassFileParser().parse(data);
             case LUA_BC: return new BinaryChunkParser().parse(data);
+            case WASM: return new WasmBinParser().parse(data);
             default: return new FileComponent() {}; // todo
         }
     }

classpy-wasm/build.gradle

@@ -0,0 +1,3 @@
+dependencies {
+    compile project(':classpy-common')
+}

classpy-wasm/src/main/java/com/github/zxh/classpy/wasm/Vector.java

@@ -0,0 +1,23 @@
+package com.github.zxh.classpy.wasm;
+
+import java.util.function.Supplier;
+
+public class Vector extends WasmBinComponent {
+
+    private Supplier<? extends WasmBinComponent> supplier;
+
+    public Vector(Supplier<? extends WasmBinComponent> supplier) {
+        this.supplier = supplier;
+    }
+
+    @Override
+    protected void readContent(WasmBinReader reader) {
+        int length = readU32(reader, "length");
+        for (int i = 0; i < length; i++) {
+            WasmBinComponent element = supplier.get();
+            add(null, element);
+            element.read(reader);
+        }
+    }
+
+}

classpy-wasm/src/main/java/com/github/zxh/classpy/wasm/WasmBinComponent.java

@@ -0,0 +1,107 @@
+package com.github.zxh.classpy.wasm;
+
+import com.github.zxh.classpy.common.FileComponent;
+import com.github.zxh.classpy.wasm.instructions.Expr;
+import com.github.zxh.classpy.wasm.types.ValType;
+import com.github.zxh.classpy.wasm.values.Byte;
+import com.github.zxh.classpy.wasm.values.Bytes;
+import com.github.zxh.classpy.wasm.values.Name;
+import com.github.zxh.classpy.wasm.values.U32;
+
+import java.util.function.Supplier;
+
+public class WasmBinComponent extends FileComponent {
+
+    public final void read(WasmBinReader reader) {
+        try {
+            int offset = reader.getPosition();
+            readContent(reader);
+            int length = reader.getPosition() - offset;
+            super.setOffset(offset);
+            super.setLength(length);
+        } catch (Exception e) {
+            System.out.println("error parsing: " + getClass());
+            throw e;
+        }
+    }
+
+    protected void readContent(WasmBinReader reader) {
+        for (FileComponent fc : getComponents()) {
+            ((WasmBinComponent) fc).read(reader);
+        }
+    }
+
+    protected void postRead() {
+
+    }
+
+    protected int readU32(WasmBinReader reader, String name) {
+        U32 u32 = new U32();
+        add(name, u32);
+        u32.read(reader);
+        return u32.getIntValue();
+    }
+
+    protected int readByte(WasmBinReader reader, String name) {
+        Byte b = new Byte();
+        add(name, b);
+        b.read(reader);
+        return b.getValue();
+    }
+
+    protected int readByte(WasmBinReader reader, String name, byte... expectedValues) {
+        Byte b = new Byte(expectedValues);
+        add(name, b);
+        b.read(reader);
+        return b.getValue();
+    }
+
+    protected byte[] readBytes(WasmBinReader reader, String name, int n) {
+        Bytes bytes = new Bytes(n);
+        add(name, bytes);
+        bytes.read(reader);
+        return bytes.getBytes();
+    }
+
+    protected <T extends WasmBinComponent> T read(WasmBinReader reader,
+                                                  String name,
+                                                  Supplier<T> supplier) {
+        T c = supplier.get();
+        add(name, c);
+        c.read(reader);
+        return c;
+    }
+
+    protected void readVector(WasmBinReader reader, String name,
+                              Supplier<? extends WasmBinComponent> supplier) {
+        Vector vec = new Vector(supplier);
+        add(name, vec);
+        vec.read(reader);
+    }
+
+    protected void _byte(String name, byte... expectedValues) {
+        add(name, new Byte(expectedValues));
+    }
+
+    protected void u32(String name) {
+        add(name, new U32());
+    }
+
+    protected void name(String name) {
+        add(name, new Name());
+    }
+
+    protected void valType(String name) {
+        add(name, new ValType());
+    }
+
+    protected void expr(String name) {
+        add(name, new Expr());
+    }
+
+    protected void vector(String name,
+                          Supplier<? extends WasmBinComponent> supplier) {
+        add(name, new Vector(supplier));
+    }
+
+}

classpy-wasm/src/main/java/com/github/zxh/classpy/wasm/WasmBinFile.java

@@ -0,0 +1,21 @@
+package com.github.zxh.classpy.wasm;
+
+import com.github.zxh.classpy.wasm.sections.Section;
+
+public class WasmBinFile extends WasmBinComponent {
+
+    protected void readContent(WasmBinReader reader) {
+        readBytes(reader, "magic", 4);
+        readBytes(reader, "version", 4);
+        readSections(reader);
+    }
+
+    private void readSections(WasmBinReader reader) {
+        while (reader.remaining() > 0) {
+            Section section = new Section();
+            add("section", section);
+            section.read(reader);
+        }
+    }
+
+}

classpy-wasm/src/main/java/com/github/zxh/classpy/wasm/WasmBinParser.java

@@ -0,0 +1,27 @@
+package com.github.zxh.classpy.wasm;
+
+import com.github.zxh.classpy.common.FileComponent;
+import com.github.zxh.classpy.common.FileParser;
+
+public class WasmBinParser implements FileParser {
+
+    @Override
+    public WasmBinFile parse(byte[] data) {
+        WasmBinFile wasm = new WasmBinFile();
+        try {
+            wasm.read(new WasmBinReader(data));
+            postRead(wasm);
+        } catch (Exception e) {
+            e.printStackTrace(System.err);
+        }
+        return wasm;
+    }
+
+    private static void postRead(WasmBinComponent bc) {
+        for (FileComponent c : bc.getComponents()) {
+            postRead((WasmBinComponent) c);
+        }
+        bc.postRead();
+    }
+
+}

classpy-wasm/src/main/java/com/github/zxh/classpy/wasm/WasmBinReader.java

@@ -0,0 +1,62 @@
+package com.github.zxh.classpy.wasm;
+
+import com.github.zxh.classpy.common.BytesReader;
+
+import java.nio.ByteOrder;
+
+public class WasmBinReader extends BytesReader {
+
+    public WasmBinReader(byte[] data) {
+        super(data, ByteOrder.LITTLE_ENDIAN); // ?
+    }
+
+    public long readU32() {
+        return readUnsignedLEB128(32);
+    }
+
+    public long readU64() {
+        return readUnsignedLEB128(64);
+    }
+
+    public long readS32() {
+        return readSignedLEB128(32);
+    }
+
+    public long readS64() {
+        return readSignedLEB128(64);
+    }
+
+    private long readUnsignedLEB128(int nBits) {
+        long result = 0;
+        for (int shift = 0; shift < nBits; shift += 7) {
+            int b = readByte();
+            result |= ((b & 0b0111_1111) << shift);
+            if ((b & 0b1000_0000) == 0) {
+                return result;
+            }
+        }
+
+        throw new RuntimeException("can not decode unsigned LEB128");
+    }
+
+    private long readSignedLEB128(int size) {
+        long result = 0;
+        int shift = 0;
+        //size = number of bits in signed integer;
+        byte b;
+        do{
+            b = readByte();
+            result |= ((b & 0b0111_1111) << shift);
+            shift += 7;
+        } while ((b & 0b1000_0000) != 0);
+
+        /* sign bit of byte is second high order bit (0x40) */
+        if ((shift < size) && ((b & 0b0100_0000) != 0)) {
+            /* sign extend */
+            result |= (~0 << shift);
+        }
+
+        return result;
+    }
+
+}

classpy-wasm/src/main/java/com/github/zxh/classpy/wasm/instructions/Expr.java

@@ -0,0 +1,18 @@
+package com.github.zxh.classpy.wasm.instructions;
+
+import com.github.zxh.classpy.wasm.WasmBinComponent;
+import com.github.zxh.classpy.wasm.WasmBinReader;
+
+public class Expr extends WasmBinComponent {
+
+    @Override
+    protected void readContent(WasmBinReader reader) {
+        while (reader.remaining() > 0) {
+            Instr instr = read(reader, null, Instr::new);
+            if (instr.getOpcode() == 0x0B) { // end
+                break;
+            }
+        }
+    }
+
+}