contrib/jwrapper: build class hierarchy into a POSet

[nit.git] / contrib / jwrapper / src / model.nit

# This file is part of NIT (http://www.nitlanguage.org).
#
# Copyright 2014 Frédéric Vachon <fredvac@gmail.com>
# Copyright 2015 Alexis Laferrière <alexis.laf@xymus.net>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Contains the java and nit type representation used to convert java to nit code
module model

import more_collections
import opts
import poset

import jtype_converter

class JavaType
        super Cloneable

        # Identifiers composing the namespace and class name
        #
        # An array of all the names that would be separated by `.`.
        # Each name may contain `$`.
        var identifier = new Array[String]

        var generic_params: nullable Array[JavaType] = null

        # Is this a void return type?
        var is_void = false

        # Is this type a vararg?
        var is_vararg = false is writable

        # Is this type based on an anonymous class?
        var is_anonymous: Bool is lazy do
                for id in identifier do
                        for part in id.split("$") do
                                if part.chars.first.is_digit then return true
                        end
                end
                return false
        end

        # Has some generic type to be resolved (T extends foo => T is resolved to foo)
        var has_unresolved_types = false

        # Dimension of primitive array: `int[][]` is 2d
        var array_dimension = 0

        fun is_primitive_array: Bool do return array_dimension > 0

        fun has_generic_params: Bool do return not generic_params == null

        fun return_cast: String do return converter.cast_as_return(self.id)

        fun param_cast: String
        do
                if self.has_generic_params then
                        return converter.cast_as_param(self.generic_params[0].id)
                end

                return converter.cast_as_param(self.id)
        end

        # Name to give an extern class wrapping this type
        fun extern_name: String
        do
                var name
                var prefix = extern_class_prefix
                if prefix == null then
                        # Use the namespace, e.g. java.lang.String -> Java_lang_String
                        assert not identifier.is_empty
                        if identifier.length == 1 then
                                name = identifier.last
                        else
                                var first = identifier.first
                                var last = identifier.last
                                var mid = identifier.subarray(1, identifier.length-2)
                                name = first.simple_capitalized + "_"
                                if mid.not_empty then name += mid.join("_") + "_"
                                name += last
                        end
                else
                        # Use the prefix and the short class name
                        # e.g. given the prefix Native: java.lang.String -> NativeString
                        name = prefix + id
                end

                if is_primitive_array then
                        name += "_" + "Array" * array_dimension
                end

                name = name.replace("-", "_")
                name = name.replace("$", "_")
                return name
        end

        # Short name of the class, mangled to remove `$` (e.g. `Set`)
        fun id: String do return identifier.last.replace("$", "")

        # Full name of this class as used in an importation (e.g. `java.lang.Set`)
        fun package_name: String do return identifier.join(".")

        # Name of this class for the extern declaration in Nit (e.g. `java.lang.Set[]`)
        fun extern_equivalent: String do return package_name + "[]" * array_dimension

        # Full name of this class with arrays and generic values (e.g. `java.lang.Set<E>[]`)
        redef fun to_s do
                var id = self.package_name

                if self.is_primitive_array then
                        id += "[]" * array_dimension
                else if self.has_generic_params then
                        var params = [for param in generic_params do param.to_s]
                        id += "<{params.join(", ")}>"
                end

                return id
        end

        # Get a copy of `self`
        redef fun clone
        do
                var jtype = new JavaType
                jtype.identifier = identifier
                jtype.generic_params = generic_params
                jtype.is_void = is_void
                jtype.is_vararg = is_vararg
                jtype.array_dimension = array_dimension
                return jtype
        end

        # Comparison based on fully qualified named
        redef fun ==(other) do return other isa JavaType and
                self.package_name == other.package_name and
                self.array_dimension == other.array_dimension

        redef fun hash do return self.package_name.hash
end

class NitType
        # Nit class name
        var identifier: String

        # If this NitType was found in `lib/android`, contains the module name to import
        var mod: nullable NitModule

        # Is this type known, wrapped and available in Nit?
        var is_known: Bool = true

        redef fun to_s do return identifier
end

# Model of a single Java class
class JavaClass
        # Type of this class
        var class_type: JavaType

        # Attributes of this class
        var attributes = new HashMap[String, JavaAttribute]

        # Methods of this class organized by their name
        var methods = new MultiHashMap[String, JavaMethod]

        # Constructors of this class
        var constructors = new Array[JavaConstructor]

        # Importations from this class
        var imports = new HashSet[NitModule]

        # Interfaces implemented by this class
        var implements = new HashSet[JavaType]

        # Super classes of this class
        var extends = new HashSet[JavaType]

        # Position of self in `model.class_hierarchy`
        var in_hierarchy: nullable POSetElement[JavaClass] = null is noserialize

        redef fun to_s do return class_type.to_s

        # Resolve the types in `other` in the context of this class
        private fun resolve_types_of(other: JavaClass)
        do
                # Methods
                for mid, method in other.methods do
                        for signature in method do
                                self.resolve(signature.return_type, signature.generic_params)
                                for param in signature.params do self.resolve(param, signature.generic_params)
                        end
                end

                # Constructors
                for signature in other.constructors do
                        for param in signature.params do self.resolve(param, signature.generic_params)
                end

                # Attributes
                for aid, attribute in other.attributes do
                        self.resolve attribute.java_type
                end
        end

        # Resolve `java_type` in the context of this class
        #
        # Replace, in place, parameter types by their bound.
        private fun resolve(java_type: JavaType, property_generic_params: nullable Array[JavaType])
        do
                # Skip types with a full package name
                if java_type.identifier.length != 1 then return

                # Skip primitive types
                if converter.type_map.keys.has(java_type.id) then return

                # Gather the generic parameters of the method, then the class
                var params = new Array[JavaType]
                if property_generic_params != null then params.add_all property_generic_params
                var class_generic_params = class_type.generic_params
                if class_generic_params != null then params.add_all class_generic_params

                # Skip if there is not parameters usable to resolve
                if params.is_empty then return

                for param in params do
                        if param.identifier == java_type.identifier then
                                # Found a marching parameter type
                                # TODO use a more precise bound
                                java_type.identifier = ["java", "lang", "Object"]
                                return
                        end
                end
        end

        redef fun hash do return class_type.hash
        redef fun ==(o) do return o isa JavaClass and o.class_type == class_type
end

# Model of all the Java class analyzed in one run
class JavaModel

        # All analyzed classes
        var classes = new HashMap[String, JavaClass]

        # Add a class in `classes`
        fun add_class(jclass: JavaClass)
        do
                var key = jclass.class_type.package_name
                classes[key] = jclass
        end

        # Unknown types, not already wrapped and not in this pass
        var unknown_types = new HashMap[JavaType, NitType]

        # Wrapped types, or classes analyzed in this pass
        var known_types = new HashMap[JavaType, NitType]

        # Get the `NitType` corresponding to the `JavaType`
        #
        # Also registers types so they can be reused and
        # to keep track of unknown types.
        fun java_to_nit_type(jtype: JavaType): NitType
        do
                # Check cache
                if known_types.keys.has(jtype) then return known_types[jtype]
                if unknown_types.keys.has(jtype) then return unknown_types[jtype]

                # Is it a compatible primitive type?
                if not jtype.is_primitive_array then
                        var name = converter.to_nit_type(jtype.id)
                        if name != null then
                                # We got a Nit equivalent
                                var nit_type = new NitType(name)
                                known_types[jtype] = nit_type
                                return nit_type
                        end
                end

                # Is being wrapped in this pass?
                var key = jtype.package_name
                if classes.keys.has(key) then
                        if jtype.array_dimension <= opt_arrays.value then
                                var nit_type = new NitType(jtype.extern_name)
                                known_types[jtype] = nit_type
                                return nit_type
                        end
                end

                # Search in lib
                var nit_type = find_extern_class[jtype.extern_equivalent]
                if nit_type != null then
                        known_types[jtype] = nit_type
                        return nit_type
                end

                # Unknown type
                nit_type = new NitType(jtype.extern_name)
                nit_type.is_known = false
                unknown_types[jtype] = nit_type
                return nit_type
        end

        # Resolve the types in methods and attributes of this class
        fun resolve_types
        do
                for id, java_class in classes do
                        java_class.resolve_types_of java_class

                        # Ask nester classes for resolve too
                        var matches = id.search_all("$")
                        for match in matches do
                                var nester_name = id.substring(0, match.from)
                                if classes.keys.has(nester_name) then
                                        var nester = classes[nester_name]
                                        nester.resolve_types_of java_class
                                end
                        end
                end
        end

        # Specialization hierarchy of `classes`
        var class_hierarchy = new POSet[JavaClass]

        # Fill `class_hierarchy`
        fun build_class_hierarchy
        do
                var object_type = new JavaType
                object_type.identifier = ["java","lang","Object"]

                # Fill POSet
                for name, java_class in classes do
                        # Skip anonymous classes
                        if java_class.class_type.is_anonymous then continue

                        java_class.in_hierarchy = class_hierarchy.add_node(java_class)

                        # Collect explicit super classes
                        var super_classes = new Array[JavaType]
                        super_classes.add_all java_class.implements
                        super_classes.add_all java_class.extends

                        # Remove unavailable super classes
                        for super_type in super_classes.reverse_iterator do
                                # Is the super class available?
                                if not classes.keys.has(super_type.package_name) then super_classes.remove(super_type)
                        end

                        # If the is no explicit supers, add `java.lang.Object`
                        if super_classes.is_empty and java_class.class_type != object_type then
                                super_classes.add object_type
                        end

                        for super_type in super_classes do
                                # Is the super class available?
                                if not classes.keys.has(super_type.package_name) then continue

                                var super_class = classes[super_type.package_name]
                                class_hierarchy.add_edge(java_class, super_class)
                        end
                end
        end
end

# A property to a Java class
abstract class JavaProperty

        # Is this property marked static?
        var is_static: Bool
end

# A Java method, with its signature
class JavaMethod
        super JavaProperty

        # Type returned by the method
        var return_type: JavaType

        # Type of the arguments of the method
        var params: Array[JavaType]

        # Generic parameters of this method
        var generic_params: Array[JavaType]

        redef fun ==(o) do return o isa JavaMethod and o.is_static == is_static and o.params == params
        redef fun hash do return params.hash
end

# An attribute in a Java class
class JavaAttribute
        super JavaProperty

        # Type of the attribute
        var java_type: JavaType
end

# A Java method, with its signature
class JavaConstructor
        # Type of the parameters of this constructor
        var params: Array[JavaType]

        # Generic parameters of this constructor
        var generic_params: Array[JavaType]
end

# A Nit module, use to import the referenced extern classes
class NitModule
        # Relative path to the module
        var path: String

        # Name of the module
        var name: String is lazy do return path.basename(".nit")

        redef fun to_s do return self.name
        redef fun ==(other) do return other isa NitModule and self.path == other.path
        redef fun hash do return self.path.hash
end

redef class Sys
        # Collection of Java classes already wrapped in the library
        #
        # * The key uses `JavaType.to_s`.
        # * The value is the corresponding `NitType`.
        var find_extern_class: DefaultMap[String, nullable NitType] is lazy do
                var map = new DefaultMap[String, nullable NitType](null)
                var modules = new HashMap[String, NitModule]

                var lib_paths = opt_libs.value
                if lib_paths == null then lib_paths = new Array[String]

                if lib_paths.has("auto") then
                        lib_paths.remove "auto"
                        var nit_dir = "NIT_DIR".environ
                        if nit_dir.is_empty then
                                # Simple heuristic to find the Nit lib
                                var dir = sys.program_name.dirname / "../../../lib/"
                                dir = dir.simplify_path
                                if dir.file_exists then lib_paths.add dir.simplify_path
                        end
                end

                if lib_paths.is_empty then return map

                # Use grep to find all extern classes implemented in Java
                var grep_regex = "extern class [a-zA-Z0-9_]\\\+[ ]\\\+in[ ]\\\+\"Java\""
                var grep_args = ["-r", "--with-filename", grep_regex]
                grep_args.add_all lib_paths

                var grep = new ProcessReader("grep", grep_args...)
                var lines = grep.read_lines
                grep.close
                grep.wait

                # Sort out the modules, Nit class names and Java types
                var regex = """(.+):\\s*extern +class +([a-zA-Z0-9_]+) *in *"Java" *`\\{(.+)`\\}""".to_re
                for line in lines do
                        var matches = line.search_all(regex)
                        for match in matches do
                                var path = match[1].to_s
                                var nit_name = match[2].to_s
                                var java_name = match[3].to_s.trim

                                # Debug code
                                # print "+ Found {nit_name}: {java_name} at {path}"

                                var mod = modules.get_or_null(path)
                                if mod == null then
                                        mod = new NitModule(path)
                                        modules[path] = mod
                                end

                                map[java_name] = new NitType(nit_name, mod)
                        end
                end

                return map
        end

        # Option to set `extern_class_prefix`
        var opt_extern_class_prefix = new OptionString("Prefix to extern classes (By default uses the full namespace)", "-p")

        # Prefix used to name extern classes, if `null` use the full namespace
        var extern_class_prefix: nullable String is lazy do return opt_extern_class_prefix.value

        # Libraries to search for existing wrappers
        var opt_libs = new OptionArray("Paths to libraries with wrappers of Java classes ('auto' to use the full Nit lib)", "-i")

        # Generate the primitive array version of each class up to the given depth
        var opt_arrays = new OptionInt("Depth of the primitive array for each wrapped class (default: 1)", 1, "-a")
end

redef class Text
        # Get a copy of `self` where the first letter is capitalized
        fun simple_capitalized: String
        do
                if is_empty then return to_s

                var c = chars.first.to_upper
                var s = c.to_s + substring_from(1)
                return s
        end
end