Java to C++ converter

h2/src/tools/org/h2/java/ClassObj.java

@@ -101,7 +101,8 @@ public class ClassObj {
             list = new ArrayList<MethodObj>();
             methods.put(method.name, list);
         } else {
-            method.name = method.name + "_" + (list.size() + 1);
+            // for overloaded methods
+            // method.name = method.name + "_" + (list.size() + 1);
         }
         list.add(method);
     }
@@ -248,6 +249,11 @@ class MethodObj {
      * Whether this is a constructor.
      */
     boolean isConstructor;
+
+    public String toString() {
+        return name;
+    }
+
 }
 
 /**
@@ -305,6 +311,10 @@ class FieldObj {
      */
     ClassObj declaredClass;
 
+    public String toString() {
+        return name;
+    }
+
 }
 
 /**
@@ -338,12 +348,12 @@ class Type {
 
     public String toString() {
         StringBuilder buff = new StringBuilder();
-        buff.append(JavaParser.toC(classObj.toString()));
-        if (!classObj.isPrimitive) {
-            buff.append("*");
+        for (int i = 0; i < arrayLevel; i++) {
+            buff.append("ptr<array< ");
         }
+        buff.append(classObj.toString());
         for (int i = 0; i < arrayLevel; i++) {
-            buff.append("*");
+            buff.append(" > >");
         }
         return buff.toString();
     }

h2/src/tools/org/h2/java/Expr.java

@@ -7,6 +7,7 @@
 package org.h2.java;
 
 import java.util.ArrayList;
+import java.util.Iterator;
 
 /**
  * An expression.
@@ -14,6 +15,7 @@ import java.util.ArrayList;
 public interface Expr {
     // toString
     Type getType();
+    Expr cast(Type type);
 }
 
 /**
@@ -52,7 +54,6 @@ class CallExpr implements Expr {
 
     public String toString() {
         StringBuilder buff = new StringBuilder();
-        String methodName;
         initMethod();
         if (method.isIgnore) {
             if (args.size() == 0) {
@@ -64,23 +65,23 @@ class CallExpr implements Expr {
                         "Cannot ignore method with multiple arguments: " + method);
             }
         } else {
-            if (method.isVirtual) {
-                methodName = "virtual_" + method.name + "[CLASS_ID("+expr.toString()+")]";
+            if (expr == null) {
+                // static method
+                buff.append(JavaParser.toC(classObj.toString() + "." + method.name));
             } else {
-                methodName = JavaParser.toC(classObj.toString() + "." + method.name);
+                buff.append(expr.toString()).append("->");
+                buff.append(method.name);
             }
-            buff.append(methodName).append("(");
+            buff.append("(");
             int i = 0;
-            if (expr != null) {
-                buff.append(expr.toString());
-                i++;
-            }
+            Iterator<FieldObj> paramIt = method.parameters.values().iterator();
             for (Expr a : args) {
                 if (i > 0) {
                     buff.append(", ");
                 }
+                FieldObj f = paramIt.next();
                 i++;
-                buff.append(a);
+                buff.append(a.cast(f.type));
             }
             buff.append(")");
         }
@@ -92,6 +93,10 @@ class CallExpr implements Expr {
         return method.returnType;
     }
 
+    public Expr cast(Type type) {
+        return this;
+    }
+
 }
 
 /**
@@ -104,19 +109,17 @@ class AssignExpr implements Expr {
     Expr right;
 
     public String toString() {
-        if (left.getType().isSimplePrimitive()) {
-            return left + " " + op + " " + right;
-        }
-        if (right.toString().equals("null")) {
-            return "release(" + left + ")";
-        }
-        return left + " = set(" + left + ", " + right + ")";
+        return left + " " + op + " " + right.cast(left.getType());
     }
 
     public Type getType() {
         return left.getType();
     }
 
+    public Expr cast(Type type) {
+        return this;
+    }
+
 }
 
 /**
@@ -135,6 +138,14 @@ class ConditionalExpr implements Expr {
         return ifTrue.getType();
     }
 
+    public Expr cast(Type type) {
+        ConditionalExpr e2 = new ConditionalExpr();
+        e2.condition = condition;
+        e2.ifTrue = ifTrue.cast(type);
+        e2.ifFalse = ifFalse.cast(type);
+        return e2;
+    }
+
 }
 
 /**
@@ -153,6 +164,9 @@ class LiteralExpr implements Expr {
     }
 
     public String toString() {
+        if ("null".equals(literal)) {
+            return JavaParser.toCType(type) + "()";
+        }
         return literal;
     }
 
@@ -164,6 +178,14 @@ class LiteralExpr implements Expr {
         return type;
     }
 
+    public Expr cast(Type type) {
+        if ("null".equals(literal)) {
+            // TODO should be immutable
+            this.type = type;
+        }
+        return this;
+    }
+
 }
 
 /**
@@ -193,13 +215,11 @@ class OpExpr implements Expr {
             if (left.getType().isObject() || right.getType().isObject()) {
                 // TODO convert primitive to to String, call toString
                 StringBuilder buff = new StringBuilder();
-                buff.append("java_lang_StringBuilder_toString(");
-                buff.append("java_lang_StringBuilder_append(");
-                buff.append("java_lang_StringBuilder_init_obj(");
+                buff.append("ptr<java_lang_StringBuilder>(new java_lang_StringBuilder(");
                 buff.append(convertToString(left));
-                buff.append("), ");
+                buff.append("))->append(");
                 buff.append(convertToString(right));
-                buff.append("))");
+                buff.append(")->toString()");
                 return buff.toString();
             }
         }
@@ -209,7 +229,7 @@ class OpExpr implements Expr {
     private String convertToString(Expr e) {
         Type t = e.getType();
         if (t.arrayLevel > 0) {
-            return e.toString() + ".toString()";
+            return e.toString() + "->toString()";
         }
         if (t.classObj.isPrimitive) {
             ClassObj wrapper = context.getWrapper(t.classObj);
@@ -217,7 +237,12 @@ class OpExpr implements Expr {
         } else if (e.getType().toString().equals("java_lang_String*")) {
             return e.toString();
         }
-        return e.toString() + ".toString()";
+        return e.toString() + "->toString()";
+    }
+
+    private static boolean isComparison(String op) {
+        return op.equals("==") || op.equals(">") || op.equals("<") ||
+                op.equals(">=") || op.equals("<=") || op.equals("!=");
     }
 
     public Type getType() {
@@ -227,6 +252,11 @@ class OpExpr implements Expr {
         if (right == null) {
             return left.getType();
         }
+        if (isComparison(op)) {
+            Type t = new Type();
+            t.classObj = JavaParser.getBuiltInClass("boolean");
+            return t;
+        }
         if (op.equals("+")) {
             if (left.getType().isObject() || right.getType().isObject()) {
                 Type t = new Type();
@@ -242,6 +272,10 @@ class OpExpr implements Expr {
         return lt;
     }
 
+    public Expr cast(Type type) {
+        return this;
+    }
+
 }
 
 /**
@@ -261,23 +295,14 @@ class NewExpr implements Expr {
     public String toString() {
         StringBuilder buff = new StringBuilder();
         if (arrayInitExpr.size() > 0) {
-            if (classObj.isPrimitive) {
-                buff.append("NEW_ARRAY(sizeof(" + classObj + ")");
-                buff.append(", 1 ");
+            buff.append("ptr<array<" + classObj + "> >(new array<" + classObj + ">(1 ");
             for (Expr e : arrayInitExpr) {
                 buff.append("* ").append(e);
             }
-                buff.append(")");
-            } else {
-                buff.append("NEW_OBJ_ARRAY(1 ");
-                for (Expr e : arrayInitExpr) {
-                    buff.append("* ").append(e);
-                }
-                buff.append(")");
-            }
+            buff.append("))");
         } else {
-            MethodObj m = classObj.getMethod("init_obj", args);
-            buff.append(JavaParser.toC(classObj.toString() + "." + m.name)).append("(");
+            buff.append("new " + JavaParser.toC(classObj.toString()));
+            buff.append("(");
             int i = 0;
             for (Expr a : args) {
                 if (i++ > 0) {
@@ -297,6 +322,10 @@ class NewExpr implements Expr {
         return t;
     }
 
+    public Expr cast(Type type) {
+        return this;
+    }
+
 }
 
 /**
@@ -386,6 +415,11 @@ class StringExpr implements Expr {
         }
         return buff.toString();
     }
+
+    public Expr cast(Type type) {
+        return this;
+    }
+
 }
 
 /**
@@ -405,24 +439,20 @@ class VariableExpr implements Expr {
     public String toString() {
         init();
         StringBuilder buff = new StringBuilder();
-        if ("length".equals(name) && base.getType().arrayLevel > 0) {
-            buff.append("LENGTH(");
-            buff.append(base.toString());
-            buff.append(")");
-        } else {
         if (base != null) {
             buff.append(base.toString()).append("->");
         }
         if (field != null) {
             if (field.isStatic) {
                 buff.append(JavaParser.toC(field.declaredClass + "." + field.name));
-                } else {
+            } else if (field.name != null) {
                 buff.append(field.name);
+            } else if ("length".equals(name) && base.getType().arrayLevel > 0) {
+                buff.append("length()");
             }
         } else {
             buff.append(JavaParser.toC(name));
         }
-        }
         return buff.toString();
     }
 
@@ -450,6 +480,10 @@ class VariableExpr implements Expr {
         return field.type;
     }
 
+    public Expr cast(Type type) {
+        return this;
+    }
+
 }
 
 /**
@@ -473,6 +507,10 @@ class ArrayExpr implements Expr {
         return expr.getType();
     }
 
+    public Expr cast(Type type) {
+        return this;
+    }
+
 }
 
 /**
@@ -500,6 +538,10 @@ class ArrayInitExpr implements Expr {
         return buff.toString();
     }
 
+    public Expr cast(Type type) {
+        return this;
+    }
+
 }
 
 /**
@@ -518,6 +560,10 @@ class CastExpr implements Expr {
         return "(" + type + ") " + expr;
     }
 
+    public Expr cast(Type type) {
+        return this;
+    }
+
 }
 
 /**
@@ -536,7 +582,11 @@ class ArrayAccessExpr implements Expr {
     }
 
     public String toString() {
-        return base + "[" + index + "]";
+        return base + "->at(" + index + ")";
+    }
+
+    public Expr cast(Type type) {
+        return this;
     }
 
 }

h2/src/tools/org/h2/java/Statement.java

@@ -38,7 +38,13 @@ class ReturnStatement extends StatementBase {
     Expr expr;
 
     public String toString() {
-        return "return " + (expr == null ? "" : expr) + ";";
+        if (expr == null) {
+            return "return;";
+        }
+        if (expr.getType().isSimplePrimitive()) {
+            return "return " + expr + ";";
+        }
+        return "return " + JavaParser.toCType(expr.getType()) + "(" + expr + ");";
     }
 
 }
@@ -187,9 +193,9 @@ class ForStatement extends StatementBase {
             Type it = iterable.getType();
             if (it != null && it.arrayLevel > 0) {
                 String idx = "i_" + iterableVariable;
-                buff.append("int " + idx + " = 0; " + idx + " < LENGTH(" + iterable + "); " + idx + "++");
+                buff.append("int " + idx + " = 0; " + idx + " < " + iterable + "->length(); " + idx + "++");
                 buff.append(") {\n");
-                buff.append(JavaParser.indent(iterableType + " " + iterableVariable + " = " + iterable + "["+ idx +"];\n"));
+                buff.append(JavaParser.indent(iterableType + " " + iterableVariable + " = " + iterable + "->at("+ idx +");\n"));
                 buff.append(block.toString()).append("}");
             } else {
                 // TODO iterate over a collection
@@ -247,7 +253,7 @@ class VarDecStatement extends StatementBase {
 
     public String toString() {
         StringBuilder buff = new StringBuilder();
-        buff.append(type).append(' ');
+        buff.append(JavaParser.toCType(type)).append(' ');
         StringBuilder assign = new StringBuilder();
         for (int i = 0; i < variables.size(); i++) {
             if (i > 0) {
@@ -260,7 +266,7 @@ class VarDecStatement extends StatementBase {
                 if (value.getType().isSimplePrimitive()) {
                     buff.append(" = ").append(value);
                 } else {
-                    assign.append(varName).append(" = reference(").append(value).append(");\n");
+                    assign.append(varName).append(" = ").append(value).append(";\n");
                 }
             }
         }

h2/src/tools/org/h2/java/Test.java

@@ -26,7 +26,7 @@ public class Test extends TestBase {
     }
 
     public void test() throws IOException {
-        // gcc --std=c99 -o test test.cpp
+        // g++ -o test test.cpp
         // chmod +x test
         // ./test
 
@@ -76,7 +76,7 @@ public class Test extends TestBase {
         parser.writeHeader(w);
         parser.writeSource(w);
         w.flush();
-        w = new PrintWriter(new FileWriter("bin/test.c"));
+        w = new PrintWriter(new FileWriter("bin/test.cpp"));
         parser.writeHeader(w);
         parser.writeSource(w);
         w.close();

h2/src/tools/org/h2/java/TestApp.java

@@ -14,7 +14,7 @@ public class TestApp {
 /* c:
 
 int main(int argc, char** argv) {
-    org_h2_java_TestApp_main(null);
+    org_h2_java_TestApp_main(ptr<array<ptr<java_lang_String> > >());
 }
 
 */
@@ -26,9 +26,7 @@ int main(int argc, char** argv) {
      */
     public static void main(String... args) {
         for (int i = 0; i < 10; i++) {
-            String s = "Hello " + i;
-            System.out.println(s);
-            s = null;
+            System.out.println("Hello " + i);
         }
     }
 

h2/src/tools/org/h2/java/io/PrintStream.java

@@ -17,8 +17,8 @@ public class PrintStream {
      * @param s the string
      */
     public void println(String s) {
-        // c: int x = LENGTH(s->chars);
-        // c: printf("%.*S\n", x, s->chars);
+        // c: int x = s->chars->length();
+        // c: printf("%.*S\n", x, s->chars->getData());
     }
 
 }

h2/src/tools/org/h2/java/lang/Integer.java

@@ -22,9 +22,9 @@ public class Integer {
      * @return the String
      */
     public static String toString(int x) {
-        // c: char ch[20];
-        // c: snprintf(ch, 20, "%d", x);
-        // c: return string(ch);
+        // c: wchar_t ch[20];
+        // c: swprintf(ch, 20, L"%d", x);
+        // c: return STRING(ch);
         // c: return;
         if (x == MIN_VALUE) {
             return String.wrap("-2147483648");

h2/src/tools/org/h2/java/lang/Object.java

@@ -11,14 +11,16 @@ package org.h2.java.lang;
  */
 public class Object {
 
-    private static final int[] K = { 1 };
-
     public int hashCode() {
-        return K[0];
+        return 0;
     }
 
     public boolean equals(Object other) {
-        return this == other;
+        return other == this;
+    }
+
+    public java.lang.String toString() {
+        return "?";
     }
 
 }

h2/src/tools/org/h2/java/lang/String.java

@@ -30,126 +30,116 @@ import org.h2.java.Ignore;
 #define false 0
 #define null 0
 
-#define LENGTH(a) (*(((jint*)(a))-3))
-#define CLASS_ID(a) (*(((jint*)(a))-2))
-#define NEW_ARRAY(size, length) new_array(0, size, length)
-#define NEW_OBJ_ARRAY(length) new_array(0, sizeof(void*), length)
-#define NEW_OBJ(typeId, typeName) new_object(typeId, sizeof(struct typeName))
-#define SET(variable, p) set_object(variable, p)
-#define STRING(s) ((java_lang_String*) string(s))
-
-void* new_array(jint object, jint size, jint length);
-void* new_object(jint type, jint size);
-void* reference(void* o);
-void release(void* o);
-void* set(void* o, void* n);
-void* string(char* s);
+#define STRING(s) ptr<java_lang_String>(new java_lang_String(ptr< array<jchar> >(new array<jchar>(s, (jint) wcslen(s)))));
 
-*/
-
-/*
- * Object layout:
- * m-2: data type
- * m-1: number of references
- * m: object data
- *
- * Array layout:
- * m-3: length (number of elements)
- * m-2: 0 (array marker)
- * m-1: number of references
- * m: first element
- */
-
-/**
- * A java.lang.String implementation.
- */
-public class String {
-
-/* c:
-
-void* new_array_with_count(jint object, jint size, jint length, jint refCount) {
-    jint count = sizeof(jint) * 3 + size * length;
-    jint* m = (jint*) calloc(1, count);
-    *m = length;
-    *(m + 2) = refCount;
-    return m + 3;
-}
-
-void* new_array(jint object, jint size, jint length) {
-    return new_array_with_count(object, size, length, 1);
-}
-
-void* new_static_array(jint object, jint size, jint length) {
-    return new_array_with_count(object, size, length, 0);
-}
-
-void* new_object_with_count(jint type, jint size, jint refCount) {
-    jint count = sizeof(jint) * 2 + size;
-    jint* m = (jint*) calloc(1, count);
-    *m = type;
-    *(m + 1) = refCount;
-    return m + 2;
-}
-
-void* new_object(jint type, jint size) {
-    return new_object_with_count(type, size, 1);
-}
-
-void* new_static_object(jint type, jint size) {
-    return new_object_with_count(type, size, 0);
-}
-
-void* reference(void* o) {
-    if (o != 0) {
-        jint* m = (jint*) o;
-        if (*(m - 1) > 0) {
-            (*(m - 1))++;
+class RefBase {
+protected:
+    jint refCount;
+public:
+    RefBase() {
+        refCount = 1;
     }
+    void reference() {
+        refCount++;
     }
-    return o;
-}
-
-void release(void* o) {
-    if (o == 0) {
-        return;
+    void release() {
+        if (--refCount == 0) {
+            delete this;
         }
-    jint* m = (jint*) o;
-    if (*(m - 1) <= 1) {
-        if (*(m - 1) == 0) {
-            return;
     }
-        if (*(m - 2) == 0) {
-            free(m - 3);
-        } else {
-            free(m - 2);
+};
+template <class T> class ptr {
+    T* pointer;
+public:
+    explicit ptr(T* p=0) : pointer(p) {
+        if (p != 0) {
+            ((RefBase*)p)->reference();
         }
-    } else {
-        (*(m - 1))--;
     }
-}
-
-void* set(void* o, void* n) {
-    release(o);
-    return reference(n);
-}
-
-void* string(char* s) {
-    jint len = strlen(s);
-    jchar* chars = NEW_ARRAY(sizeof(jchar), len);
-    for (int i = 0; i < len; i++) {
-        chars[i] = s[i];
+    ptr(const ptr<T>& p) : pointer(p.pointer) {
+        if (p.pointer != 0) {
+            ((RefBase*)p.pointer)->reference();
         }
-    return java_lang_String_init_obj(chars);
-}
+    }
+    ~ptr() {
+        if (pointer != 0) {
+            ((RefBase*)pointer)->release();
+        }
+    }
+    ptr<T>& operator= (const ptr<T>& p) {
+        if (this != &p && pointer != p.pointer) {
+            if (pointer != 0) {
+                ((RefBase*)pointer)->release();
+            }
+            pointer = p.pointer;
+            if (pointer != 0) {
+                ((RefBase*)pointer)->reference();
+            }
+        }
+        return *this;
+    }
+    T& operator*() {
+        return *pointer;
+    }
+    T* operator->() {
+        return pointer;
+    }
+    jboolean operator==(const ptr<T>& p) {
+        return pointer == p->pointer;
+    }
+    jboolean operator==(const RefBase* t) {
+        return pointer == t;
+    }
+};
+template <class T> class array : RefBase {
+    jint len;
+    T* data;
+public:
+    array(const T* d, jint len) {
+        this->len = len;
+        data = new T[len];
+        memcpy(data, d, sizeof(T) * len);
+    }
+    array(jint len) {
+        this->len = len;
+        data = new T[len];
+    }
+    ~array() {
+        delete[] data;
+    }
+    T* getData() {
+        return data;
+    }
+    jint length() {
+        return len;
+    }
+    T& operator[](jint index) {
+        if (index < 0 || index >= len) {
+            throw "index set";
+        }
+        return data[index];
+    }
+    T& at(jint index) {
+        if (index < 0 || index >= len) {
+            throw "index set";
+        }
+        return data[index];
+    }
+};
 
 */
 
+/**
+ * A java.lang.String implementation.
+ */
+public class String {
+
     /**
      * The character array.
      */
     char[] chars;
 
-    private int hashCode;
+    private int hash;
 
     public String(char[] chars) {
         this.chars = new char[chars.length];
@@ -162,7 +152,7 @@ void* string(char* s) {
     }
 
     public int hashCode() {
-        if (hashCode == 0) {
+        if (hash == 0) {
             if (chars.length == 0) {
                 return 0;
             }
@@ -170,10 +160,10 @@ void* string(char* s) {
             for (char c : chars) {
                 h = h * 31 + c;
             }
-            hashCode = h;
+            hash = h;
             return h;
         }
-        return hashCode;
+        return hash;
     }
 
     /**
@@ -185,6 +175,10 @@ void* string(char* s) {
         return chars.length;
     }
 
+    public String toStringMethod() {
+        return this;
+    }
+
     @Ignore
     public java.lang.String asString() {
         return new java.lang.String(chars);

h2/src/tools/org/h2/java/lang/System.java

@@ -30,8 +30,8 @@ public class System {
      */
     public static void arraycopy(char[] src, int srcPos, char[] dest, int destPos, int length) {
         /* c:
-        memmove(((jchar*)dest) + destPos,
-            ((jchar*)src) + srcPos, sizeof(jchar) * length);
+        memmove(((jchar*)dest->getData()) + destPos,
+            ((jchar*)src->getData()) + srcPos, sizeof(jchar) * length);
         */
         // c: return;
         java.lang.System.arraycopy(src, srcPos, dest, destPos, length);
@@ -49,8 +49,8 @@ public class System {
      */
     public static void arraycopy(byte[] src, int srcPos, byte[] dest, int destPos, int length) {
         /* c:
-        memmove(((jbyte*)dest) + destPos,
-            ((jbyte*)src) + srcPos, sizeof(jbyte) * length);
+        memmove(((jbyte*)dest->getData()) + destPos,
+            ((jbyte*)src->getData()) + srcPos, sizeof(jbyte) * length);
         */
         // c: return;
         java.lang.System.arraycopy(src, srcPos, dest, destPos, length);