A Java parser / Java to C converter.

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

@@ -54,7 +54,9 @@ public class ClassObj {
      */
     LinkedHashMap<String, MethodObj> methods = new LinkedHashMap<String, MethodObj>();
 
-    ArrayList<Statement> nativeInitializers = new ArrayList<Statement>();
+    ArrayList<Statement> nativeCode = new ArrayList<Statement>();
+
+    String id;
 
     /**
      * Add a method.

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

@@ -21,14 +21,33 @@ public interface Expr {
  */
 class CallExpr implements Expr {
 
-    Expr expr;
-    String name;
-    ArrayList<Expr> args = new ArrayList<Expr>();
+    final JavaParser context;
+    final Expr expr;
+    final ArrayList<Expr> args = new ArrayList<Expr>();
+    final boolean isStatic;
+    final String className;
+    final String name;
+
+    CallExpr(JavaParser context, Expr expr, String className, String name, boolean isStatic) {
+        this.context = context;
+        this.expr = expr;
+        this.className = className;
+        this.name = name;
+        this.isStatic = isStatic;
+    }
 
     public String toString() {
         StringBuilder buff = new StringBuilder();
-        buff.append(expr.toString() + "_" + JavaParser.toC(name)).append("(");
+        if (className != null) {
+            buff.append(JavaParser.toC(className + "." + name)).append("(");
+        } else {
+            buff.append(JavaParser.toC(expr.getType().type.name + "." + name)).append("(");
+        }
         int i = 0;
+        if (expr != null) {
+            buff.append(expr.toString());
+            i++;
+        }
         for (Expr a : args) {
             if (i > 0) {
                 buff.append(", ");
@@ -38,10 +57,12 @@ class CallExpr implements Expr {
         }
         return buff.append(")").toString();
     }
+
     public Type getType() {
         // TODO
         return null;
     }
+
 }
 
 /**
@@ -136,9 +157,23 @@ class NewExpr implements Expr {
 
     public String toString() {
         StringBuilder buff = new StringBuilder();
-        buff.append("new " + type);
-        for (Expr e : arrayInitExpr) {
-            buff.append("[").append(e).append("]");
+        if (arrayInitExpr.size() > 0) {
+            if (type.isPrimitive) {
+                buff.append("NEW_ARRAY(sizeof(" + type + ")");
+                buff.append(", 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(")");
+            }
+        } else {
+            buff.append("NEW_OBJ(" + type.id + ", " + type + ")");
         }
         return buff.toString();
     }
@@ -237,13 +272,23 @@ class VariableExpr implements Expr {
 
     public String toString() {
         StringBuilder buff = new StringBuilder();
-        if (base != null) {
-            buff.append(base.toString()).append("->");
-        }
-        if (field != null) {
-            buff.append(field.name);
+        if (field != null && "length".equals(field.name) && base != null && base.getType() != null && base.getType().arrayLevel > 0) {
+            buff.append("LENGTH(");
+            buff.append(base.toString());
+            buff.append(")");
         } else {
-            buff.append(JavaParser.toC(name));
+            if (base != null) {
+                buff.append(base.toString()).append("->");
+            }
+            if (field != null) {
+                if (field.isStatic) {
+                    buff.append(JavaParser.toC(field.type.type.name + "." + field.name));
+                } else {
+                    buff.append(field.name);
+                }
+            } else {
+                buff.append(JavaParser.toC(name));
+            }
         }
         return buff.toString();
     }
@@ -262,12 +307,12 @@ class VariableExpr implements Expr {
  */
 class ArrayExpr implements Expr {
 
-    Expr obj;
+    Expr expr;
     ArrayList<Expr> indexes = new ArrayList<Expr>();
 
     public String toString() {
         StringBuilder buff = new StringBuilder();
-        buff.append(obj.toString());
+        buff.append(expr.toString());
         for (Expr e : indexes) {
             buff.append('[').append(e.toString()).append(']');
         }
@@ -275,7 +320,7 @@ class ArrayExpr implements Expr {
     }
 
     public Type getType() {
-        return obj.getType();
+        return expr.getType();
     }
 
 }

h2/src/tools/org/h2/java/JavaParser.java

@@ -10,6 +10,7 @@ import java.io.IOException;
 import java.io.PrintWriter;
 import java.io.RandomAccessFile;
 import java.text.ParseException;
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
@@ -41,6 +42,8 @@ public class JavaParser {
     private HashMap<String, ClassObj> classes = new HashMap<String, ClassObj>();
     private LinkedHashMap<String, FieldObj> localFields = new LinkedHashMap<String, FieldObj>();
 
+    private ArrayList<Statement> nativeHeaders = new ArrayList<Statement>();
+
     static {
         String[] list = new String[] { "abstract", "continue", "for", "new", "switch", "assert", "default", "if",
                 "package", "synchronized", "boolean", "do", "goto", "private", "this", "break", "double", "implements",
@@ -122,6 +125,13 @@ public class JavaParser {
             importMap.put(importClass, importPackageName);
             read(";");
         }
+        while (true) {
+            Statement s = readNativeStatementIf();
+            if (s == null) {
+                break;
+            }
+            nativeHeaders.add(s);
+        }
         while (true) {
             classObj = new ClassObj();
             classObj.isPublic = readIf("public");
@@ -192,9 +202,12 @@ public class JavaParser {
                 break;
             }
             thisPointer = null;
-            Statement s = readNativeStatementIf();
-            if (s != null) {
-                classObj.nativeInitializers.add(s);
+            while (true) {
+                Statement s = readNativeStatementIf();
+                if (s == null) {
+                    break;
+                }
+                classObj.nativeCode.add(s);
             }
             thisPointer = null;
             boolean isStatic = false;
@@ -354,6 +367,7 @@ public class JavaParser {
             }
             StatementNative stat = new StatementNative();
             stat.code = source.substring(start, current.index).trim();
+            current.index += 2;
             read();
             return stat;
         }
@@ -618,9 +632,7 @@ public class JavaParser {
             if (readIf(".")) {
                 String n = readIdentifier();
                 if (readIf("(")) {
-                    CallExpr e2 = new CallExpr();
-                    e2.expr = expr;
-                    e2.name = n;
+                    CallExpr e2 = new CallExpr(this, expr, null, n, false);
                     if (!readIf(")")) {
                         while (true) {
                             e2.args.add(readExpr());
@@ -696,11 +708,7 @@ public class JavaParser {
         }
         String name = readIdentifier();
         if (readIf("(")) {
-            CallExpr expr = new CallExpr();
-            expr.name  = name;
-            VariableExpr ve = new VariableExpr();
-            ve.field = thisPointer;
-            expr.expr = ve;
+            CallExpr expr = new CallExpr(this, null, classObj.name, name, false);
             if (!readIf(")")) {
                 while (true) {
                     expr.args.add(readExpr());
@@ -720,13 +728,41 @@ public class JavaParser {
                 f = classObj.instanceFields.get(name);
                 if (f == null) {
                     String imp = importMap.get(name);
+                    if (imp == null) {
+                        imp = JAVA_IMPORT_MAP.get(name);
+                    }
                     if (imp != null) {
                         name = imp;
+                        if (readIf(".")) {
+                            String n = readIdentifier();
+                            if (readIf("(")) {
+                                CallExpr e2 = new CallExpr(this, null, imp, n, true);
+                                if (!readIf(")")) {
+                                    while (true) {
+                                        e2.args.add(readExpr());
+                                        if (!readIf(",")) {
+                                            read(")");
+                                            break;
+                                        }
+                                    }
+                                }
+                                return e2;
+                            }
+                            VariableExpr e2 = new VariableExpr();
+                            // static member variable
+                            e2.name = imp + "." + n;
+                            ClassObj c = classes.get(imp);
+                            FieldObj sf = c.staticFields.get(n);
+                            e2.field = sf;
+                            return e2;
+                        }
+                        // TODO static field or method of a class
                     }
+                } else {
+                    expr.field = f;
                 }
             }
         }
-        expr.field = f;
         if (f != null && (!f.isLocal && !f.isStatic)) {
             VariableExpr ve = new VariableExpr();
             ve.field = thisPointer;
@@ -1143,16 +1179,17 @@ public class JavaParser {
      * @param out the output writer
      */
     void writeHeader(PrintWriter out) {
+        for (Statement s : nativeHeaders) {
+            out.println(s);
+        }
+        out.println();
         for (ClassObj c : classes.values()) {
             out.println("/* " + c.name + ".h */");
             for (FieldObj f : c.staticFields.values()) {
                 if (f.isFinal) {
                     out.println("#define " + toC(c.name + "." + f.name) + " (" + f.value + ")");
                 } else {
-                    out.print("extern " + toC(f.type.toString()) + " " + f.name);
-                    if (f.value != null) {
-                        out.print(" = " + f.value);
-                    }
+                    out.print("extern " + toC(f.type.toString()) + " " + toC(c.name + "." + f.name));
                     out.println(";");
                 }
             }
@@ -1164,7 +1201,11 @@ public class JavaParser {
                 }
                 out.println(";");
             }
+            if (c.instanceFields.size() == 0) {
+                out.println("int dummy;");
+            }
             out.println("};");
+            out.println("typedef struct " + toC(c.name) + " " + toC(c.name) + ";");
             for (MethodObj m : c.methods.values()) {
                 out.print(m.returnType + " " + toC(c.name) + "_" + m.name + "(");
                 int i = 0;
@@ -1193,9 +1234,18 @@ public class JavaParser {
     void writeSource(PrintWriter out) {
         for (ClassObj c : classes.values()) {
             out.println("/* " + c.name + ".c */");
-            for (Statement s : c.nativeInitializers) {
+            for (Statement s : c.nativeCode) {
                 out.println(s);
             }
+            for (FieldObj f : c.staticFields.values()) {
+                if (!f.isFinal) {
+                    out.print(toC(f.type.toString()) + " " + toC(c.name + "." + f.name));
+                    if (f.value != null) {
+                        out.print(" = " + f.value);
+                    }
+                    out.println(";");
+                }
+            }
             for (MethodObj m : c.methods.values()) {
                 out.print(m.returnType + " " + toC(c.name) + "_" + m.name + "(");
                 int i = 0;
@@ -1257,6 +1307,10 @@ public class JavaParser {
         return identifier.replace('.', '_');
     }
 
+    ClassObj getClassObj() {
+        return classObj;
+    }
+
 }
 
 /**

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

@@ -12,7 +12,9 @@ import java.util.ArrayList;
  * A statement.
  */
 public interface Statement {
+
     // toString
+
 }
 
 /**
@@ -143,9 +145,21 @@ class ForStatement implements Statement {
         StringBuffer buff = new StringBuffer();
         buff.append("for (");
         if (iterableType != null) {
-            buff.append(iterableType).append(' ');
-            buff.append(iterableVariable).append(": ");
-            buff.append(iterable);
+            Type it = iterable.getType();
+            if (it != null && it.arrayLevel > 0) {
+                String idx = "i_" + iterableVariable;
+                buff.append("int " + idx + " = 0; " + idx + " < LEN(" + iterable + "); " + idx + "++");
+                buff.append(") {\n");
+                buff.append(JavaParser.indent(iterableType + " " + iterableVariable + " = " + iterable + "["+ idx +"];\n"));
+                buff.append(block.toString()).append("}");
+            } else {
+                // TODO iterate over a collection
+                buff.append(iterableType).append(' ');
+                buff.append(iterableVariable).append(": ");
+                buff.append(iterable);
+                buff.append(") {\n");
+                buff.append(block.toString()).append("}");
+            }
         } else {
             buff.append(init.toString());
             buff.append(" ").append(condition.toString()).append("; ");
@@ -155,9 +169,9 @@ class ForStatement implements Statement {
                 }
                 buff.append(updates.get(i));
             }
+            buff.append(") {\n");
+            buff.append(block.toString()).append("}");
         }
-        buff.append(") {\n");
-        buff.append(block.toString()).append("}");
         return buff.toString();
     }
 }

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

@@ -34,7 +34,6 @@ public class Test extends TestBase {
         // import *
         // initializer blocks
         // access to static fields with instance variable
-        // method call with "this": this.toString()
         // final variables (within blocks, parameter list)
         // Identifier : (labels)
         // ClassOrInterfaceDeclaration within blocks (or any other nested classes)
@@ -56,6 +55,7 @@ public class Test extends TestBase {
         assertEquals("6.022137e+23f", JavaParser.readNumber("6.022137e+23f+1"));
 
         JavaParser parser = new JavaParser();
+        parser.parse("src/tools/org/h2", "java.lang.Object");
         parser.parse("src/tools/org/h2", "java.lang.String");
         parser.parse("src/tools/org/h2", "java.io.PrintStream");
         parser.parse("src/tools/org/h2", "java.lang.System");

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

 package org.h2.java.lang;
 
+/* c:
+
+#define boolean int
+
+#define LENGTH(a) (*(((int*)(a))-1))
+#define NEW_ARRAY(size, length) new_array(0, size, length)
+#define NEW_OBJ_ARRAY(length) new_array(1, sizeof(void*), length)
+#define NEW_OBJ(type, size) new_object(type, sizeof(struct type))
+#define SET(variable, p) set_object(variable, p)
+
+void* new_array(int object, int size, int length);
+void* new_object(int type, int size);
+void* set_object(void** target, void* o);
+
+*/
+
 /**
  * A java.lang.String implementation.
  */
 public class String {
 
+/* c:
+
+#include <stdlib.h>
+
+void* new_array(int object, int size, int length) {
+    int count = sizeof(int) * 2 + size * length;
+    int* m = (int*) calloc(1, count);
+    *m = object << 31 + length;
+    *(m+1) = 1;
+    return m + 2;
+}
+
+void* new_object(int type, int size) {
+    int count = sizeof(int) * 2 + size;
+    int* m = (int*) calloc(1, count);
+    *m = type;
+    *(m+1) = 1;
+    return m + 2;
+}
+
+void* set_object(void** target, void* o) {
+    int* m = (int*) target;
+    if (*(m - 2) == 1) {
+        free(m - 1);
+    } else {
+         (*(m - 2))--;
+    }
+    *target = o;
+    m = (int*) target;
+    if (o != 0) {
+        (*(m - 2))++;
+    }
+}
+
+*/
+
     private char[] chars;
     private int hashCode;