root/trunk/ProjectFortress/src/com/sun/fortress/repository/ForeignJava.java @ 3284

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    Copyright 2009 Sun Microsystems, Inc.,
    4150 Network Circle, Santa Clara, California 95054, U.S.A.
    All rights reserved.

    U.S. Government Rights - Commercial software.
    Government users are subject to the Sun Microsystems, Inc. standard
    license agreement and applicable provisions of the FAR and its supplements.

    Use is subject to license terms.

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    trademarks of Sun Microsystems, Inc. in the U.S. and other countries.
 ******************************************************************************/

package com.sun.fortress.repository;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import com.sun.fortress.compiler.IndexBuilder;
import com.sun.fortress.compiler.index.ApiIndex;
import com.sun.fortress.exceptions.StaticError;
import com.sun.fortress.nodes.APIName;
import com.sun.fortress.nodes.AliasedAPIName;
import com.sun.fortress.nodes.AliasedSimpleName;
import com.sun.fortress.nodes.Api;
import com.sun.fortress.nodes.BaseType;
import com.sun.fortress.nodes.Decl;
import com.sun.fortress.nodes.Expr;
import com.sun.fortress.nodes.FnDecl;
import com.sun.fortress.nodes.Id;
import com.sun.fortress.nodes.IdOrOpOrAnonymousName;
import com.sun.fortress.nodes.Import;
import com.sun.fortress.nodes.ImportApi;
import com.sun.fortress.nodes.ImportNames;
import com.sun.fortress.nodes.Param;
import com.sun.fortress.nodes.StaticParam;
import com.sun.fortress.nodes.TraitObjectDecl;
import com.sun.fortress.nodes.TraitTypeWhere;
import com.sun.fortress.nodes.Type;
import com.sun.fortress.nodes.WhereClause;
import com.sun.fortress.nodes_util.Modifiers;
import com.sun.fortress.nodes_util.NodeFactory;
import com.sun.fortress.nodes_util.NodeUtil;
import com.sun.fortress.nodes_util.Span;
import com.sun.fortress.useful.Bijection;
import com.sun.fortress.useful.HashBijection;
import com.sun.fortress.useful.MultiMap;
import com.sun.fortress.useful.Useful;

import edu.rice.cs.plt.tuple.Option;

public class ForeignJava {

    /** given an API Name, what Java class does it import?  (Name of existing
     * Java class, not its wrapper.)
     */
    MultiMap<APIName, Class> javaImplementedAPIs = new MultiMap<APIName, Class>();
    MultiMap<APIName, APIName> generatedImports = new MultiMap<APIName, APIName>();
    
    /**
     * Given an API Name, what are the decls in it?
     * This includes both trait (class) decls and function (static method) decls.
     */
    MultiMap<APIName, Decl> apiToStaticDecls = new MultiMap<APIName, Decl>();

    /**
     * Given a Java class, what items from it were requested?
     * Possibilities are:
     * 1) Non-empty strings; those particular things.
     * 2) Empty string; the entire class.
     * 3) Nothing at all; an opaque import.
     */
    MultiMap<Class, String> itemsFromClasses = new MultiMap<Class, String>();
    
    Bijection<Method, FnDecl> methodToDecl = new HashBijection<Method, FnDecl>();
    Bijection<Class, TraitObjectDecl> classToTraitDecl = new HashBijection<Class, TraitObjectDecl>();

    /* Special cases
     * 
     * Boolean
     * Byte
     * Character
     * Short
     * Int
     * Long
     * Float
     * Double
     * 
     * all of the above, .TYPE (the primitives)
     * 
     * 
     * String
     */
    
    static Span span = NodeFactory.internalSpan;

    static Map<Class, Type> specialCases = new HashMap<Class, Type>();
    static APIName fortLib =
        NodeFactory.makeAPIName(span, "FortressLibrary");
    
    static void s(Class cl, APIName api, String str) {
        specialCases.put(cl, NodeFactory.makeTraitType(span, false, NodeFactory.makeId(span, api, str)));
    }
    
    static {
        s(Boolean.class, fortLib, "Boolean");
        s(Boolean.TYPE, fortLib, "Boolean");
        s(Integer.class, fortLib, "ZZ32");
        s(Integer.TYPE, fortLib, "ZZ32");
        s(Long.class, fortLib, "ZZ64");
        s(Long.TYPE, fortLib, "ZZ64");
        s(Float.class, fortLib, "RR32");
        s(Float.TYPE, fortLib, "RR32");
        s(Double.class, fortLib, "RR64");
        s(Double.TYPE, fortLib, "RR64");
        s(String.class, fortLib, "String");
        s(BigInteger.class, fortLib, "ZZ");
        specialCases.put(Void.TYPE, NodeFactory.makeVoidType(span));
    }
    
    APIName packageToAPIName(Package p) {
        return NodeFactory.makeAPIName(span, p.getName());
    }

    void processJavaImport(Import i, ImportNames ins) {
        APIName pkg_name = ins.getApiName();
        String pkg_name_string = pkg_name.getText();
        List<AliasedSimpleName> names = ins.getAliasedNames();
        for (AliasedSimpleName name : names) {
            Option<IdOrOpOrAnonymousName> opt_alias = name.getAlias();
            if (opt_alias.isSome()) {
                throw StaticError.make(
                "Import aliasing not yet implemented for foreign imports ", i);
            }

            IdOrOpOrAnonymousName imported = name.getName();
            Option<APIName> dotted_prefix = imported.getApiName();
            String suffix = NodeUtil.nameString(imported);
            /*
             * Okay, so this means that the "api" being imported
             * is pkg_name, and the class is specified either as
             * the first part of the prefix (which looks like an
             * APIName) or the suffix.
             *
             * Possible cases:
             *
             * Aclass.AnInnerClass (Map.Entry)
             * Aclass.AStaticFunction
             * Aclass.AField
             * Aclass.AnInner*.{AStaticFunction,AField}
             */
            
            /*
             * More hints.
             * The api part of the name, corresponds to a package name.
             * So, if it is an inner class, that dot has to come
             * in the suffix.
             * 
             * Inner classes expect a dollar sign where the dot
             * appears in the Java text.
             */
            
            /*
             * There can be static inner classes,
             * static functions,
             * and static fields,
             * all with the same dotted name.
             * 
             * For now, try the static inner class first,
             * then the function,
             * then the fields.
             */
            
            
            int last_dot = suffix.length();
            
            /* Try replacing fewer and fewer dots with $; prefer the
             * "classiest" answer.
             */
            Class imported_class = null;
            while (last_dot > 0) {
                String candidate_class = suffix.substring(0,last_dot);
                candidate_class = pkg_name_string + "." + Useful.replace(candidate_class, ".", "$");
                    try {
                        imported_class = Class.forName(candidate_class);
                        break;
                        // exit with imported_class and last_dot
                    } catch (ClassNotFoundException e) {
                        // failed to get this one
                    }
                last_dot = suffix.lastIndexOf('.', last_dot);
            }
            if (imported_class == null) {
                // Could not match a class to any prefix
                throw StaticError.make("Could not find any Java package.class prefix of  "+ pkg_name_string + "." + suffix, i);
            }
            /* imported_class specifies the class,
             * the item is the unused portion of the suffix.
             */
            String imported_item = suffix.substring(last_dot);
            if (imported_item.length() == 0) {
                
            } else if (imported_item.startsWith(".", 0)) {
                imported_item = imported_item.substring(1);
            } else {
                throw StaticError.make("Internal error processing imported item " + imported_item, i);
            }
            /* Record import of (part of) pkg_name_string.
             * Class imported_class
             * item imported_item -- entire class if "".
             */
            // TODO
            recurOnClass(pkg_name, imported_class, imported_item);
            
        } /* for name : names */
        System.err.println("javaImplementedAPIs="+javaImplementedAPIs);
        System.err.println("itemsFromClasses="+itemsFromClasses);
    }

    /**
     * @param imported_class
     */
    private Type recurOnOpaqueClass(APIName importing_package, Class imported_class) {
        // Need to special-case for primitives, String, Object, void.
        // Also, not a bijection.
        Type  t = specialCases.get(imported_class);
        if (t != null)
            return t;
        
        Package p = imported_class.getPackage();
        APIName api_name = packageToAPIName(p);
        
        /* Though the class may have been previously referenced, the import
         * may still need to be recorded.  Re-recording an existing import
         * is harmless.
         */
        generatedImports.putItem(importing_package, api_name);
        
        Id name = NodeFactory.makeId(span, imported_class.getSimpleName());
        
        /*
         *  Has there (not) been any reference to this class previously?
         *  If no reference, then record that it is needed (opaquely) and
         *  create a trivial declaration for it, and enter the declaration
         *  into the appropriate places.
         */
        if (!itemsFromClasses.containsKey(imported_class)) {
            itemsFromClasses.putKey(imported_class);
            // Construct a minimal trait declaration for this class.
            classToTraitType(imported_class, api_name, name, Collections.<Decl>emptyList());
        };
        
        name = NodeFactory.makeId(api_name, name);
        // Note: a TraitType is a reference to a trait.
        return NodeFactory.makeTraitType(span, false, name);
    }

    private void classToTraitType(Class imported_class, APIName api_name,
            Id name, List<Decl> decls) {
        List<StaticParam> sparams = Collections.emptyList();
        List<TraitTypeWhere> extendsC = Collections.emptyList();
        Modifiers mods = Modifiers.None;
        Option<WhereClause> whereC = Option.none();
        List<BaseType> excludesC = Collections.emptyList();
        Option<List<BaseType>> comprisesC = Option.none();
        TraitObjectDecl tod = NodeFactory.makeTraitDecl (span, mods, name, sparams, extendsC, whereC, decls, excludesC, comprisesC);
        // Need to fake up an API for this class, too.
        classToTraitDecl.put(imported_class, tod);
        apiToStaticDecls.putItem(api_name, tod);
        javaImplementedAPIs.putItem(api_name, imported_class);
    }
    
    private void recurOnClass(APIName pkg_name, Class imported_class, String imported_item) {
        Set<String> old = itemsFromClasses.get(imported_class);
        
        /*
         * Import of a class, non-opaquely.
         * Keep track of which items, specifically, are imported.
         * Note that the empty string is a valid item, it means "the class itself".
         */
        if (old != null && old.size() > 0) { 
            itemsFromClasses.putItem(imported_class, imported_item);
            return;
        }
        
        /*
         * Class not seen before (except perhaps as an opaque import)
         * Recursively visit all of its parts.
         */
        itemsFromClasses.putItem(imported_class, imported_item);

        Method[] methods = imported_class.getDeclaredMethods();
        Field[] fields = imported_class.getDeclaredFields();
        Class[] interfaces = imported_class.getInterfaces();
        Class super_class = imported_class.getSuperclass();
        
        ArrayList<Decl> trait_decls = new ArrayList<Decl>();
        
        for (Method m : methods) {
            if (isPublic(m.getModifiers())) {
                if (isStatic(m.getModifiers())) {
                 // static goes to api-indexed set
                    FnDecl decl = recurOnMethod(pkg_name, imported_class, m, true);
                    apiToStaticDecls.putItem(pkg_name, decl);
                } else {
                    // non static goes to declaration pile for class
                    FnDecl decl = recurOnMethod(pkg_name, imported_class, m, false);
                    trait_decls.add(decl);
                }
            }
        }
        
        Id name = NodeFactory.makeId(span, imported_class.getSimpleName());
        classToTraitType(imported_class, pkg_name, name, trait_decls);
        
    }

    private FnDecl recurOnMethod(APIName importing_package, Class cl, Method m, boolean is_static) {
        if (methodToDecl.containsKey(m))
            return methodToDecl.get(m);
        
        Class rt = m.getReturnType();
        Class[] pts = m.getParameterTypes();
        // To construct a FnDecl, need to get names for all the other types
        Type return_type = recurOnOpaqueClass(importing_package, rt);
        
        List<Param> params = new ArrayList<Param>(pts.length);
        int i = 0;
        for (Class pt : pts) {
            Type type = recurOnOpaqueClass(importing_package, pt);
            Id id = NodeFactory.makeId(span, "p"+(i++));
            Param p = NodeFactory.makeParam(id, type);
            params.add(p);
        }
        Id id = is_static ?
                NodeFactory.makeId(span, cl.getSimpleName()+"."+ m.getName()) :
            NodeFactory.makeId(span, m.getName());
        FnDecl fndecl = NodeFactory.makeFnDecl(span, Modifiers.None,
                id, params,Option.some(return_type), Option.<Expr>none());
        methodToDecl.put(m, fndecl);
        return fndecl;
    }

    private boolean isPublic(int modifiers) {
        return 0 != (modifiers & java.lang.reflect.Modifier.PUBLIC);
    }
    
    private boolean isStatic(int modifiers) {
        return 0 != (modifiers & java.lang.reflect.Modifier.STATIC);
    }

    public boolean definesApi(APIName name) {
        return javaImplementedAPIs.containsKey(name);
    }

    public ApiIndex fakeApi(APIName name) {
        Set<Class> classes = javaImplementedAPIs.get(name);
        // Need to generate wrappers for all these classes,
        //  if they do not already exist.

        List<Import> imports = new ArrayList<Import>();
        for (APIName a : generatedImports.get(name)) {
            AliasedAPIName aan = NodeFactory.makeAliasedAPIName(a);
            /*
             * Hoping to lie, slightly, to static analysis.
             * This is technically speaking a "foreign" import,
             * but the import is already known to the ForeignJava
             * data structures, and this allows use of fully qualified
             * (hence unambiguous) references to classes from other packages
             * in the generated API.
             * 
             * So, one lie -- no foreign annotation.
             */
            ImportApi iapi = NodeFactory.makeImportApi(span, Option.<String>none(), Useful.list(aan));
            imports.add(iapi);
        }
        
        List<Decl> decls = new ArrayList<Decl>();
        for (Decl d : apiToStaticDecls.get(name)) {
            decls.add(d);
        }
        Api a =  NodeFactory.makeApi( span,  name,
                    imports,
                    decls);
        
        return IndexBuilder.builder.buildApiIndex(a, Long.MIN_VALUE+2);
        
    }

}