compile: add 'Program' class to represent a nit program

[nit.git] / src / compiling / compiling_global.nit

# This file is part of NIT ( http://www.nitlanguage.org ).
#
# Copyright 2008 Jean Privat <jean@pryen.org>
#
# 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.

# Compute and generate tables for classes and modules.
package compiling_global

import program
private import compiling_icode

# Something that store color of table elements
class ColorContext
        var _colors: HashMap[TableElt, Int] = new HashMap[TableElt, Int]

        # The color of a table element.
        fun color(e: TableElt): Int
        do
                return _colors[e]
        end

        # Is a table element already colored?
        fun has_color(e: TableElt): Bool
        do
                return _colors.has_key(e)
        end

        # Assign a color to a table element.
        fun color=(e: TableElt, c: Int)
        do
                _colors[e] = c
                var idx = c
                for i in [0..e.length[ do
                        _colors[e.item(i)] = idx
                        idx = idx + 1
                end
        end
end

# All information and results of the global analysis.
class GlobalAnalysis
special ColorContext
        # Associate global classes to compiled classes
        readable var _compiled_classes: HashMap[MMGlobalClass, CompiledClass] = new HashMap[MMGlobalClass, CompiledClass]

        # The main module of the program globally analysed
        readable var _module: MMModule

        # FIXME: do something better.
        readable writable var _max_class_table_length: Int = 0

        init(module: MMModule)
        do
                _module = module
        end
end

class GlobalCompilerVisitor
special CompilerVisitor
        # The global analysis result
        readable var _global_analysis: GlobalAnalysis
        init(m: MMModule, tc: ToolContext, ga: GlobalAnalysis)
        do
                super(m, tc)
                _global_analysis = ga
        end
end

# A compiled class is a class in a program
class CompiledClass
special ColorContext
        # The corresponding local class in the main module of the prgram
        readable var _local_class: MMLocalClass

        # The identifier of the class
        readable writable var _id: Int = 0

        # The full class table of the class
        readable var _class_table: Array[nullable TableElt] = new Array[nullable TableElt]

        # The full instance table of the class
        readable var _instance_table: Array[nullable TableElt] = new Array[nullable TableElt]

        # The proper class table part (no superclasses but all refinements)
        readable writable var _class_layout: TableEltComposite = new TableEltComposite(self)

        # The proper instance table part (no superclasses but all refinements)
        readable writable var _instance_layout: TableEltComposite = new TableEltComposite(self)

        init(c: MMLocalClass) do _local_class = c
end

redef class MMConcreteClass
        # The table element of the subtype check
        fun class_color_pos: TableEltClassColor do return _class_color_pos.as(not null)
        var _class_color_pos: nullable TableEltClassColor

        # The proper local class table part (nor superclasses nor refinments)
        readable var _class_layout: Array[TableElt] = new Array[TableElt]

        # The proper local instance table part (nor superclasses nor refinments)
        readable var _instance_layout: Array[TableElt] = new Array[TableElt]

        # Build the local layout of the class and feed the module table
        fun build_layout_in(tc: ToolContext, module_table: Array[ModuleTableElt])
        do
                var clt = _class_layout
                var ilt = _instance_layout

                if global.intro == self then
                        module_table.add(new TableEltClassId(self))
                        var cpp = new TableEltClassColor(self)
                        _class_color_pos = cpp
                        module_table.add(cpp)
                        clt.add(new TableEltClassInitTable(self))
                end
                for p in local_local_properties do
                        var pg = p.global
                        if pg.intro == p then
                                if p isa MMAttribute then
                                        ilt.add(new TableEltAttr(p))
                                else if p isa MMMethod then
                                        clt.add(new TableEltMeth(p))
                                end
                        end
                        if p isa MMMethod and p.need_super then
                                clt.add(new TableEltSuper(p))
                        end
                end

                if not ilt.is_empty then
                        var teg = new ModuleTableEltGroup
                        teg.elements.append(ilt)
                        module_table.add(teg)
                end

                if not clt.is_empty then
                        var teg = new ModuleTableEltGroup
                        teg.elements.append(clt)
                        module_table.add(teg)
                end
        end
end

redef class Program
        # Do the complete global analysis
        fun global_analysis(cctx: ToolContext): GlobalAnalysis
        do
                var ga = new GlobalAnalysis(module)
                var smallest_classes = new Array[MMLocalClass]
                var global_properties = new HashSet[MMGlobalProperty]
                var ctab = new Array[TableElt]
                var itab = new Array[TableElt]

                ctab.add(new TableEltClassSelfId)
                ctab.add(new TableEltClassObjectSize)
                itab.add(new TableEltVftPointer)
                itab.add(new TableEltObjectId)

                var pclassid = -1
                var classid = 3

                # We have to work on ALL the classes of the module
                var classes = new Array[MMLocalClass]
                for c in module.local_classes do
                        c.compute_super_classes
                        classes.add(c)
                end
                (new ClassSorter).sort(classes)

                for c in classes do
                        # Finish processing the class (if invisible)
                        c.compute_ancestors
                        c.inherit_global_properties

                        # Associate a CompiledClass to the class
                        var cc = new CompiledClass(c)
                        ga.compiled_classes[c.global] = cc

                        # Assign a unique class identifier
                        # (negative are for primitive classes)
                        var gc = c.global
                        var bm = gc.module
                        if c.primitive_info != null then
                                cc.id = pclassid
                                pclassid = pclassid - 4
                        else
                                cc.id = classid
                                classid = classid + 4
                        end

                        # Register is the class is a leaf
                        if c.cshe.direct_smallers.is_empty then
                                smallest_classes.add(c)
                        end

                        # Store the colortableelt in the class table pool
                        var bc = c.global.intro
                        assert bc isa MMConcreteClass
                        ctab.add(bc.class_color_pos)
                end

                # Compute core and crown classes for colorization
                var crown_classes = new HashSet[MMLocalClass]
                var core_classes = new HashSet[MMLocalClass]
                for c in smallest_classes do
                        while c.cshe.direct_greaters.length == 1 do
                                c = c.cshe.direct_greaters.first
                        end
                        crown_classes.add(c)
                        core_classes.add_all(c.cshe.greaters_and_self)
                end
                #print("nbclasses: {classes.length} leaves: {smallest_classes.length} crown: {crown_classes.length} core: {core_classes.length}")

                # Colorize core color for typechecks
                colorize(ga, ctab, crown_classes, 0)

                # Compute tables for typechecks
                var maxcolor = 0
                for c in classes do
                        var cc = ga.compiled_classes[c.global]
                        if core_classes.has(c) then
                                # For core classes, just build the table
                                build_tables_in(cc.class_table, ga, c, ctab)
                                if maxcolor < cc.class_table.length then maxcolor = cc.class_table.length
                        else
                                # For other classes, it's easier: just append to the parent tables
                                var sc = c.cshe.direct_greaters.first
                                var scc = ga.compiled_classes[sc.global]
                                assert cc.class_table.is_empty
                                cc.class_table.add_all(scc.class_table)
                                var bc = c.global.intro
                                assert bc isa MMConcreteClass
                                var colpos = bc.class_color_pos
                                var colposcolor = cc.class_table.length
                                ga.color(colpos) = colposcolor
                                cc.class_table.add(colpos)
                                if maxcolor < colposcolor then maxcolor = colposcolor
                        end
                end
                ga.max_class_table_length = maxcolor + 1

                # Fill class table and instance tables pools
                for c in classes do
                        var cc = ga.compiled_classes[c.global]
                        var cte = cc.class_layout
                        var ite = cc.instance_layout
                        for sc in c.crhe.greaters_and_self do
                                if sc isa MMConcreteClass then
                                        cte.add(sc, sc.class_layout)
                                        ite.add(sc, sc.instance_layout)
                                end
                        end

                        if core_classes.has(c) then
                                if cte.length > 0 then
                                        ctab.add(cte)
                                end
                                if ite.length > 0 then
                                        itab.add(ite)
                                end
                        end
                end

                # Colorize all elements in pools tables
                colorize(ga, ctab, crown_classes, maxcolor+1)
                colorize(ga, itab, crown_classes, 0)

                # Build class and instance tables now things are colored
                ga.max_class_table_length = 0
                for c in classes do
                        var cc = ga.compiled_classes[c.global]
                        if core_classes.has(c) then
                                # For core classes, just build the table
                                build_tables_in(cc.class_table, ga, c, ctab)
                                build_tables_in(cc.instance_table, ga, c, itab)
                        else
                                # For other classes, it's easier: just append to the parent tables
                                var sc = c.cshe.direct_greaters.first
                                var scc = ga.compiled_classes[sc.global]
                                cc.class_table.clear
                                cc.class_table.add_all(scc.class_table)
                                var bc = c.global.intro
                                assert bc isa MMConcreteClass
                                var colpos = bc.class_color_pos
                                cc.class_table[ga.color(colpos)] = colpos
                                while cc.class_table.length <= maxcolor do
                                        cc.class_table.add(null)
                                end
                                append_to_table(ga, cc.class_table, cc.class_layout)
                                assert cc.instance_table.is_empty
                                cc.instance_table.add_all(scc.instance_table)
                                append_to_table(ga, cc.instance_table, cc.instance_layout)
                        end
                end

                return ga
        end

        # Perform coloring
        fun colorize(ga: GlobalAnalysis, elts: Array[TableElt], classes: Collection[MMLocalClass], startcolor: Int)
        do
                var colors = new HashMap[Int, Array[TableElt]]
                var rel_classes = new Array[MMLocalClass]
                for e in elts do
                        var color = -1
                        var len = e.length
                        if ga.has_color(e) then
                                color = ga.color(e)
                        else
                                rel_classes.clear
                                for c in classes do
                                        if e.is_related_to(c) then
                                                rel_classes.add(c)
                                        end
                                end
                                var trycolor = startcolor
                                while trycolor != color do
                                        color = trycolor
                                        for c in rel_classes do
                                                var idx = 0
                                                while idx < len do
                                                        if colors.has_key(trycolor + idx) and not free_color(colors[trycolor + idx], c) then
                                                                trycolor = trycolor + idx + 1
                                                                idx = 0
                                                        else
                                                                idx = idx + 1
                                                        end
                                                end
                                        end
                                end
                                ga.color(e) = color
                        end
                        for idx in [0..len[ do
                                if colors.has_key(color + idx) then
                                        colors[color + idx].add(e)
                                else
                                        colors[color + idx] = [e]
                                end
                        end
                end
        end

        private fun free_color(es: Array[TableElt], c: MMLocalClass): Bool
        do
                for e2 in es do
                        if e2.is_related_to(c) then
                                return false
                        end
                end
                return true
        end

        private fun append_to_table(cc: ColorContext, table: Array[nullable TableElt], cmp: TableEltComposite)
        do
                for j in [0..cmp.length[ do
                        var e = cmp.item(j)
                        cc.color(e) = table.length
                        table.add(e)
                end
        end

        private fun build_tables_in(table: Array[nullable TableElt], ga: GlobalAnalysis, c: MMLocalClass, elts: Array[TableElt])
        do
                var tab = new HashMap[Int, TableElt]
                var len = 0
                for e in elts do
                        if e.is_related_to(c) then
                                var col = ga.color(e)
                                var l = col + e.length
                                tab[col] = e
                                if len < l then
                                        len = l
                                end
                        end
                end
                var i = 0
                while i < len do
                        if tab.has_key(i) then
                                var e = tab[i]
                                for j in [0..e.length[ do
                                        table[i] = e.item(j)
                                        i = i + 1
                                end
                        else
                                table[i] = null
                                i = i + 1
                        end
                end
        end

        # Compile module and class tables
        fun compile_tables_to_c(v: GlobalCompilerVisitor)
        do
                for m in module.mhe.greaters_and_self do
                        m.compile_local_table_to_c(v)
                end

                for c in module.local_classes do
                        c.compile_tables_to_c(v)
                end
                var s = new Buffer.from("classtable_t TAG2VFT[4] = \{NULL")
                for t in ["Int","Char","Bool"] do
                        if module.has_global_class_named(t.to_symbol) then
                                s.append(", (const classtable_t)VFT_{t}")
                        else
                                s.append(", NULL")
                        end
                end
                s.append("};")
                v.add_instr(s.to_s)
        end

        # Compile main part (for _table.c)
        fun compile_main_part(v: GlobalCompilerVisitor)
        do
                v.add_instr("int main(int argc, char **argv) \{")
                v.indent
                v.add_instr("prepare_signals();")
                v.add_instr("glob_argc = argc; glob_argv = argv;")
                var sysname = once "Sys".to_symbol
                if not module.has_global_class_named(sysname) then
                        print("No main")
                else
                        var sys = module.class_by_name(sysname)
                        var name = once "main".to_symbol
                        if not sys.has_global_property_by_name(name) then
                                print("No main")
                        else
                                var mainm = sys.select_method(name)
                                v.add_instr("G_sys = NEW_Sys();")
                                v.add_instr("register_static_object(&G_sys);")
                                v.add_instr("{mainm.cname}(G_sys);")
                        end
                end
                v.add_instr("return 0;")
                v.unindent
                v.add_instr("}")
        end
end

redef class MMModule
        # The local table of the module (refers things introduced in the module)
        var _local_table: Array[ModuleTableElt] = new Array[ModuleTableElt]

        # Builds the local tables and local classes layouts
        fun local_analysis(tc: ToolContext)
        do
                for c in local_classes do
                        if c isa MMConcreteClass then
                                c.build_layout_in(tc, _local_table)
                        end
                end
        end

        # Declare class table (for _sep.h)
        fun declare_class_tables_to_c(v: GlobalCompilerVisitor)
        do
                for c in local_classes do
                        if c.global.module == self then
                                c.declare_tables_to_c(v)
                        end
                end
        end

        # Compile sep files
        fun compile_mod_to_c(v: GlobalCompilerVisitor)
        do
                v.add_decl("extern const char *LOCATE_{name};")
                if not v.tc.global then
                        v.add_decl("extern const int SFT_{name}[];")
                end
                var i = 0
                for e in _local_table do
                        var value: String
                        if v.tc.global then
                                value = "{e.value(v.global_analysis)}"
                        else
                                value = "SFT_{name}[{i}]"
                                i = i + 1
                        end
                        e.compile_macros(v, value)
                end
                for c in local_classes do
                        if not c isa MMConcreteClass then continue
                        for pg in c.global_properties do
                                var p = c[pg]
                                if p.local_class == c and p isa MMMethod then
                                        p.compile_property_to_c(v)
                                end
                                if pg.is_init_for(c) then
                                        # Declare constructors
                                        var params = new Array[String]
                                        for j in [0..p.signature.arity[ do
                                                params.add("val_t p{j}")
                                        end
                                        v.add_decl("val_t NEW_{c}_{p.global.intro.cname}({params.join(", ")});")
                                end
                        end
                end
        end

        # Compile module file for the current module
        fun compile_local_table_to_c(v: GlobalCompilerVisitor)
        do
                v.add_instr("const char *LOCATE_{name} = \"{location.file}\";")

                if v.tc.global or _local_table.is_empty then
                        return
                end

                v.add_instr("const int SFT_{name}[{_local_table.length}] = \{")
                v.indent
                for e in _local_table do
                        v.add_instr(e.value(v.global_analysis) + ",")
                end
                v.unindent
                v.add_instr("\};")
        end
end

###############################################################################

# An element of a class, an instance or a module table
abstract class AbsTableElt
        # Compile the macro needed to use the element and other related elements
        fun compile_macros(v: GlobalCompilerVisitor, value: String) is abstract
end

# An element of a class or an instance table
# Such an elements represent method function pointers, attribute values, etc.
abstract class TableElt
special AbsTableElt
        # Is the element conflict to class `c' (used for coloring)
        fun is_related_to(c: MMLocalClass): Bool is abstract

        # Number of sub-elements. 1 if none
        fun length: Int do return 1

        # Access the ith subelement.
        fun item(i: Int): TableElt do return self

        # Return the value of the element for a given class
        fun compile_to_c(v: GlobalCompilerVisitor, c: MMLocalClass): String is abstract
end

# An element of a module table
# Such an elements represent colors or identifiers
abstract class ModuleTableElt
special AbsTableElt
        # Return the value of the element once the global analisys is performed
        fun value(ga: GlobalAnalysis): String is abstract
end

# An element of a module table that represents a group of TableElt defined in the same local class
class ModuleTableEltGroup
special ModuleTableElt
        readable var _elements: Array[TableElt] = new Array[TableElt]

        redef fun value(ga) do return "{ga.color(_elements.first)} /* Group of ? */"
        redef fun compile_macros(v, value)
        do
                var i = 0
                for e in _elements do
                        e.compile_macros(v, "{value} + {i}")
                        i += 1
                end
        end
end

# An element that represents a class property
abstract class TableEltProp
special TableElt
        var _property: MMLocalProperty

        init(p: MMLocalProperty)
        do
                _property = p
        end
end

# An element that represents a function pointer to a global method
class TableEltMeth
special TableEltProp
        redef fun compile_macros(v, value)
        do
                var pg = _property.global
                v.add_decl("#define {pg.meth_call}(recv) (({pg.intro.cname}_t)CALL((recv), ({value})))")
        end

        redef fun compile_to_c(v, c)
        do
                var p = c[_property.global]
                return p.cname
        end
end

# An element that represents a function pointer to the super method of a local method
class TableEltSuper
special TableEltProp
        redef fun compile_macros(v, value)
        do
                var p = _property
                v.add_decl("#define {p.super_meth_call}(recv) (({p.cname}_t)CALL((recv), ({value})))")
        end

        redef fun compile_to_c(v, c)
        do
                var pc = _property.local_class
                var g = _property.global
                var lin = c.che.linear_extension
                var found = false
                for s in lin do
                        #print "{c.module}::{c} for {pc.module}::{pc}::{_property} try {s.module}:{s}"
                        if s == pc then
                                found = true
                        else if found and c.che < s then
                                if s.has_global_property(g) then
                                        #print "found {s.module}::{s}::{p}"
                                        return s[g].cname
                                end
                        end
                end
                abort
        end
end

# An element that represents the value stored for a global attribute
class TableEltAttr
special TableEltProp
        redef fun compile_macros(v, value)
        do
                var pg = _property.global
                v.add_decl("#define {pg.attr_access}(recv) ATTR(recv, ({value}))")
        end

        redef fun compile_to_c(v, c)
        do
                var ga = v.global_analysis
                var p = c[_property.global]
                return "/* {ga.color(self)}: Attribute {c}::{p} */"
        end
end

# An element representing a class information
class AbsTableEltClass
special AbsTableElt
        # The local class where the information comes from
        var _local_class: MMLocalClass

        init(c: MMLocalClass)
        do
                _local_class = c
        end

        # The C macro name refering the value
        fun symbol: String is abstract

        redef fun compile_macros(v, value)
        do
                v.add_decl("#define {symbol} ({value})")
        end
end

# An element of a class table representing a class information
class TableEltClass
special TableElt
special AbsTableEltClass
        redef fun is_related_to(c)
        do
                var bc = c.module[_local_class.global]
                return c.cshe <= bc
        end
end

# An element representing the id of a class in a module table
class TableEltClassId
special ModuleTableElt
special AbsTableEltClass
        redef fun symbol do return _local_class.global.id_id

        redef fun value(ga)
        do
                return "{ga.compiled_classes[_local_class.global].id} /* Id of {_local_class} */"
        end
end

# An element representing the constructor marker position in a class table
class TableEltClassInitTable
special TableEltClass
        redef fun symbol do return _local_class.global.init_table_pos_id

        redef fun compile_to_c(v, c)
        do
                var ga = v.global_analysis
                var cc = ga.compiled_classes[_local_class.global]
                var linext = c.cshe.reverse_linear_extension
                var i = 0
                while linext[i].global != _local_class.global do
                        i += 1
                end
                return "{i} /* {ga.color(self)}: {c} < {cc.local_class}: superclass init_table position */"
        end
end

# An element used for a cast
# Note: this element is both a TableElt and a ModuleTableElt.
# At the TableElt offset, there is the id of the super-class
# At the ModuleTableElt offset, there is the TableElt offset (ie. the color of the super-class).
class TableEltClassColor
special TableEltClass
special ModuleTableElt
        redef fun symbol do return _local_class.global.color_id

        redef fun value(ga)
        do
                return "{ga.color(self)} /* Color of {_local_class} */"
        end

        redef fun compile_to_c(v, c)
        do
                var ga = v.global_analysis
                var cc = ga.compiled_classes[_local_class.global]
                return "{cc.id} /* {ga.color(self)}: {c} < {cc.local_class}: superclass typecheck marker */"
        end
end

# A Group of elements introduced in the same global-class that are colored together
class TableEltComposite
special TableElt
        var _table: Array[TableElt]
        var _cc: CompiledClass
        var _offsets: HashMap[MMLocalClass, Int]
        redef fun length do return _table.length
        redef fun is_related_to(c) do return c.cshe <= _cc.local_class

        fun add(c: MMLocalClass, tab: Array[TableElt])
        do
                _offsets[c] = _table.length
                _table.append(tab)
        end

        redef fun item(i) do return _table[i]

        redef fun compile_to_c(v, c) do abort

        init(cc: CompiledClass)
        do
                _cc = cc
                _table = new Array[TableElt]
                _offsets = new HashMap[MMLocalClass, Int]
        end
end

# The element that represent the class id
class TableEltClassSelfId
special TableElt
        redef fun is_related_to(c) do return true
        redef fun compile_to_c(v, c)
        do
                var ga = v.global_analysis
                return "{v.global_analysis.compiled_classes[c.global].id} /* {ga.color(self)}: Identity */"
        end
end


# The element that represent the Object Size
class TableEltClassObjectSize
special TableElt
        redef fun is_related_to(c) do return true
        redef fun compile_to_c(v, c)
        do
        var nb = 0
        var ga = v.global_analysis
                if c.name == "NativeArray".to_symbol then
                        nb = -1
                else
                        var cc = ga.compiled_classes[c.global]
                        var itab = cc.instance_table
                        for e in itab do
                                nb += 1
                        end
                end
                return "{nb} /* {ga.color(self)}: Object size (-1 if a NativeArray)*/"
        end
end

# The element that represent the object id
class TableEltObjectId
special TableElt
        redef fun is_related_to(c) do return true
        redef fun compile_to_c(v, c)
        do
                var ga = v.global_analysis
                return "/* {ga.color(self)}: Object_id */"
        end
end

# The element that
class TableEltVftPointer
special TableElt
        redef fun is_related_to(c) do return true
        redef fun compile_to_c(v, c)
        do
                var ga = v.global_analysis
                return "/* {ga.color(self)}: Pointer to the classtable */"
        end
end

###############################################################################

# Used to sort local class in a deterministic total order
# The total order superset the class refinement and the class specialisation relations
class ClassSorter
special AbstractSorter[MMLocalClass]
        redef fun compare(a, b) do return a.compare(b)
        init do end
end

redef class MMLocalClass
        # Comparaison in a total order that superset the class refinement and the class specialisation relations
        fun compare(b: MMLocalClass): Int
        do
                var a = self
                if a == b then
                        return 0
                else if a.module.mhe < b.module then
                        return 1
                else if b.module.mhe < a.module then
                        return -1
                end
                var ar = a.cshe.rank
                var br = b.cshe.rank
                if ar > br then
                        return 1
                else if br > ar then
                        return -1
                else
                        return b.name.to_s <=> a.name.to_s
                end
        end

        # Declaration and macros related to the class table
        fun declare_tables_to_c(v: GlobalCompilerVisitor)
        do
                v.add_decl("")
                var pi = primitive_info
                v.add_decl("extern const classtable_elt_t VFT_{name}[];")
                if name == "NativeArray".to_symbol then
                        v.add_decl("val_t NEW_NativeArray(size_t length, size_t size);")
                else if pi == null then
                        # v.add_decl("val_t NEW_{name}(void);")
                else if not pi.tagged then
                        var t = pi.cname
                        var tbox = "struct TBOX_{name}"
                        v.add_decl("{tbox} \{ const classtable_elt_t * vft; bigint object_id; {t} val;};")
                        v.add_decl("val_t BOX_{name}({t} val);")
                        v.add_decl("#define UNBOX_{name}(x) ((({tbox} *)(VAL2OBJ(x)))->val)")
                end
        end

        # Compilation of table and new (or box)
        fun compile_tables_to_c(v: GlobalCompilerVisitor)
        do
                var cc = v.global_analysis.compiled_classes[self.global]
                var ctab = cc.class_table
                var clen = ctab.length
                if v.global_analysis.max_class_table_length > ctab.length then
                        clen = v.global_analysis.max_class_table_length
                end

                v.add_instr("const classtable_elt_t VFT_{name}[{clen}] = \{")
                v.indent
                for e in ctab do
                        if e == null then
                                v.add_instr("\{0} /* Class Hole :( */,")
                        else
                                v.add_instr("\{(bigint) {e.compile_to_c(v, self)}},")
                        end
                end
                if clen > ctab.length then
                        v.add_instr("\{0},"*(clen-ctab.length))
                end
                v.unindent
                v.add_instr("};")
                var itab = cc.instance_table
                for e in itab do
                        if e == null then
                                v.add_instr("/* Instance Hole :( */")
                        else
                                v.add_instr(e.compile_to_c(v, self))
                        end
                end

                var pi = primitive_info
                if name == "NativeArray".to_symbol then
                        v.add_instr("val_t NEW_NativeArray(size_t length, size_t size) \{")
                        v.indent
                        v.add_instr("Nit_NativeArray array;")
                        v.add_instr("array = (Nit_NativeArray)alloc(sizeof(struct Nit_NativeArray) + ((length - 1) * size));")
                        v.add_instr("array->vft = (classtable_elt_t*)VFT_{name};")
                        v.add_instr("array->object_id = object_id_counter;")
                        v.add_instr("object_id_counter = object_id_counter + 1;")
                        v.add_instr("array->size = length;")
                        v.add_instr("return OBJ2VAL(array);")
                        v.unindent
                        v.add_instr("}")
                else if pi == null then
                        do
                                # Generate INIT_ATTRIBUTES routine
                                var iself = new IRegister(get_type)
                                var iselfa = [iself]
                                var iroutine = new IRoutine(iselfa, null)
                                var icb = new ICodeBuilder(module, iroutine)

                                for g in global_properties do
                                        var p = self[g]
                                        var t = p.signature.return_type
                                        if p isa MMAttribute and t != null then
                                                var ir = p.iroutine
                                                if ir == null then continue
                                                # FIXME: Not compatible with sep compilation
                                                var e = icb.inline_routine(ir, iselfa, null).as(not null)
                                                icb.stmt(new IAttrWrite(p, iself, e))
                                        end
                                end

                                var cname = "INIT_ATTRIBUTES__{name}"
                                var args = iroutine.compile_signature_to_c(v, cname, "init attributes of {name}", null, null)
                                var ctx_old = v.ctx
                                v.ctx = new CContext
                                iroutine.compile_to_c(v, cname, args)
                                ctx_old.append(v.ctx)
                                v.ctx = ctx_old
                                v.unindent
                                v.add_instr("}")
                        end
                        do
                                # Generate NEW routine
                                v.add_decl("val_t NEW_{name}(void);")
                                v.add_instr("val_t NEW_{name}(void)")
                                v.add_instr("\{")
                                v.indent
                                v.add_instr("obj_t obj;")
                                v.add_instr("obj = alloc(sizeof(val_t) * {itab.length});")
                                v.add_instr("obj->vft = (classtable_elt_t*)VFT_{name};")
                                v.add_instr("obj[1].object_id = object_id_counter;")
                                v.add_instr("object_id_counter = object_id_counter + 1;")
                                v.add_instr("return OBJ2VAL(obj);")
                                v.unindent
                                v.add_instr("}")
                        end
                        do
                                # Compile CHECKNAME
                                var iself = new IRegister(get_type)
                                var iselfa = [iself]
                                var iroutine = new IRoutine(iselfa, null)
                                var icb = new ICodeBuilder(module, iroutine)
                                for g in global_properties do
                                        var p = self[g]
                                        var t = p.signature.return_type
                                        if p isa MMAttribute and t != null and not t.is_nullable then
                                                icb.add_attr_check(p, iself)
                                        end
                                end
                                var cname = "CHECKNEW_{name}"
                                var args = iroutine.compile_signature_to_c(v, cname, "check new {name}", null, null)
                                var ctx_old = v.ctx
                                v.ctx = new CContext
                                iroutine.compile_to_c(v, cname, args)
                                ctx_old.append(v.ctx)
                                v.ctx = ctx_old
                                v.unindent
                                v.add_instr("}")
                        end

                        var init_table_size = cshe.greaters.length + 1
                        var init_table_decl = "int init_table[{init_table_size}] = \{0{", 0" * (init_table_size-1)}};"

                        for g in global_properties do
                                var p = self[g]
                                # FIXME skip invisible constructors
                                if not p.global.is_init_for(self) then continue
                                assert p isa MMMethod

                                var iself = new IRegister(get_type)
                                var iparams = new Array[IRegister]
                                for i in [0..p.signature.arity[ do iparams.add(new IRegister(p.signature[i]))
                                var iroutine = new IRoutine(iparams, iself)
                                iroutine.location = p.iroutine.location
                                var icb = new ICodeBuilder(module, iroutine)

                                var inew = new IAllocateInstance(get_type)
                                inew.result = iself
                                icb.stmt(inew)
                                var iargs = [iself]
                                iargs.add_all(iparams)

                                icb.stmt(new IInitAttributes(get_type, iself))
                                icb.stmt(new IStaticCall(p, iargs))
                                icb.stmt(new ICheckInstance(get_type, iself))

                                var cname = "NEW_{self}_{p.global.intro.cname}"
                                var new_args = iroutine.compile_signature_to_c(v, cname, "new {self} {p.full_name}", null, null)
                                var ctx_old = v.ctx
                                v.ctx = new CContext
                                v.add_instr(init_table_decl)
                                var e = iroutine.compile_to_c(v, cname, new_args).as(not null)
                                v.add_instr("return {e};")
                                ctx_old.append(v.ctx)
                                v.ctx = ctx_old
                                v.unindent
                                v.add_instr("}")
                        end
                else if not pi.tagged then
                        var t = pi.cname
                        var tbox = "struct TBOX_{name}"
                        v.add_instr("val_t BOX_{name}({t} val) \{")
                        v.indent
                        v.add_instr("{tbox} *box = ({tbox}*)alloc(sizeof({tbox}));")
                        v.add_instr("box->vft = VFT_{name};")
                        v.add_instr("box->val = val;")
                        v.add_instr("box->object_id = object_id_counter;")
                        v.add_instr("object_id_counter = object_id_counter + 1;")
                        v.add_instr("return OBJ2VAL(box);")
                        v.unindent
                        v.add_instr("}")
                end
        end
end

redef class MMMethod
        fun compile_property_to_c(v: CompilerVisitor)
        do
                var ir = iroutine
                assert ir != null

                var more_params: nullable String = null
                if global.is_init then more_params = "int* init_table"
                var args = ir.compile_signature_to_c(v, cname, full_name, null, more_params)
                var ctx_old = v.ctx
                v.ctx = new CContext

                v.out_contexts.clear

                var itpos: nullable String = null
                if global.is_init then
                        itpos = "itpos{v.new_number}"
                        v.add_decl("int {itpos} = VAL2OBJ({args.first})->vft[{local_class.global.init_table_pos_id}].i;")
                        v.add_instr("if (init_table[{itpos}]) return;")
                end

                var s = ir.compile_to_c(v, cname, args)

                if itpos != null then
                        v.add_instr("init_table[{itpos}] = 1;")
                end
                if s == null then
                        v.add_instr("return;")
                else
                        v.add_instr("return ", s, ";")
                end

                ctx_old.append(v.ctx)
                v.ctx = ctx_old
                v.unindent
                v.add_instr("}")

                for ctx in v.out_contexts do v.ctx.merge(ctx)
        end
end