Merge: doc: fixed some typos and other misc. corrections
[nit.git] / src / modelbuilder.nit
index bd4fa35..b442704 100644 (file)
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Load nit source files and build the associated model
-#
-# FIXME better doc
-#
-# FIXME split this module into submodules
-# FIXME add missing error checks
 module modelbuilder
 
-import parser
-import model
-import poset
-import opts
-import toolcontext
+import loader
+import phase
+
+private import more_collections
 
 ###
 
 redef class ToolContext
-       # Option --path
-       readable var _opt_path: OptionArray = new OptionArray("Set include path for loaders (may be used more than once)", "-I", "--path")
-
-       # Option --only-metamodel
-       readable var _opt_only_metamodel: OptionBool = new OptionBool("Stop after meta-model processing", "--only-metamodel")
-
-       # Option --only-parse
-       readable var _opt_only_parse: OptionBool = new OptionBool("Only proceed to parse step of loaders", "--only-parse")
+       # Option --ignore-visibility
+       var opt_ignore_visibility = new OptionBool("Do not check, and produce errors, on visibility issues", "--ignore-visibility")
 
        redef init
        do
                super
-               option_context.add_option(opt_path, opt_only_parse, opt_only_metamodel)
-       end
-end
-
-# A model builder knows how to load nit source files and build the associated model
-# The important function is `parse_and_build' that does all the job.
-# The others function can be used for specific tasks
-class ModelBuilder
-       # The model where new modules, classes and properties are added
-       var model: Model
-
-       # The toolcontext used to control the interaction with the user (getting options and displaying messages)
-       var toolcontext: ToolContext
-
-       # Instantiate a modelbuilder for a model and a toolcontext
-       # Important, the options of the toolcontext must be correctly set (parse_option already called)
-       init(model: Model, toolcontext: ToolContext)
-       do
-               self.model = model
-               self.toolcontext = toolcontext
-
-               # Setup the paths value
-               paths.append(toolcontext.opt_path.value)
-
-               var path_env = "NIT_PATH".environ
-               if not path_env.is_empty then
-                       paths.append(path_env.split_with(':'))
-               end
-
-               path_env = "NIT_DIR".environ
-               if not path_env.is_empty then
-                       var libname = "{path_env}/lib"
-                       if libname.file_exists then paths.add(libname)
-               end
-
-               var libname = "{sys.program_name.dirname}/../lib"
-               if libname.file_exists then paths.add(libname.simplify_path)
-       end
-
-       # Load and analyze a bunch of modules.
-       # `modules' can contains filenames or module names.
-       # Imported modules are automatically loaded, builds and analysed.
-       # The result is the corresponding built modules.
-       # Errors and warnings are printed with the toolcontext.
-       #
-       # FIXME: Maybe just let the client do the loop (instead of playing with Sequences)
-       fun parse_and_build(modules: Sequence[String]): Array[MModule]
-       do
-               var mmodules = parse(modules)
-
-               if self.toolcontext.opt_only_parse.value then
-                       self.toolcontext.info("--only-parse: stop processing", 2)
-                       return new Array[MModule]
-               end
-
-               # Build the model
-               var time1 = get_time
-               self.toolcontext.info("*** BUILD MODEL ***", 1)
-               self.build_all_classes
-               var time2 = get_time
-               self.toolcontext.info("*** END BUILD MODEL: {time2-time1} ***", 2)
-
-               self.toolcontext.check_errors
-
-               return mmodules
-       end
-
-       fun parse(modules: Sequence[String]): Array[MModule]
-       do
-               var time0 = get_time
-               # Parse and recursively load
-               self.toolcontext.info("*** PARSE ***", 1)
-               var mmodules = new Array[MModule]
-               for a in modules do
-                       var nmodule = self.load_module(null, a)
-                       if nmodule == null then continue # Skip error
-                       mmodules.add(nmodule.mmodule.as(not null))
-               end
-               var time1 = get_time
-               self.toolcontext.info("*** END PARSE: {time1-time0} ***", 2)
-
-               self.toolcontext.check_errors
-               return mmodules
-       end
-
-       # Return a class named `name' visible by the module `mmodule'.
-       # Visibility in modules is correctly handled.
-       # If no such a class exists, then null is returned.
-       # If more than one class exists, then an error on `anode' is displayed and null is returned.
-       # FIXME: add a way to handle class name conflict
-       fun try_get_mclass_by_name(anode: ANode, mmodule: MModule, name: String): nullable MClass
-       do
-               var classes = model.get_mclasses_by_name(name)
-               if classes == null then
-                       return null
-               end
-
-               var res: nullable MClass = null
-               for mclass in classes do
-                       if not mmodule.in_importation <= mclass.intro_mmodule then continue
-                       if not mmodule.is_visible(mclass.intro_mmodule, mclass.visibility) then continue
-                       if res == null then
-                               res = mclass
-                       else
-                               error(anode, "Ambigous class name '{name}'; conflict between {mclass.full_name} and {res.full_name}")
-                               return null
-                       end
-               end
-               return res
-       end
-
-       # Return a property named `name' on the type `mtype' visible in the module `mmodule'.
-       # Visibility in modules is correctly handled.
-       # Protected properties are returned (it is up to the caller to check and reject protected properties).
-       # If no such a property exists, then null is returned.
-       # If more than one property exists, then an error on `anode' is displayed and null is returned.
-       # FIXME: add a way to handle property name conflict
-       fun try_get_mproperty_by_name2(anode: ANode, mmodule: MModule, mtype: MType, name: String): nullable MProperty
-       do
-               var props = self.model.get_mproperties_by_name(name)
-               if props == null then
-                       return null
-               end
-
-               var cache = self.try_get_mproperty_by_name2_cache[mmodule, mtype, name]
-               if cache != null then return cache
-
-               var res: nullable MProperty = null
-               var ress: nullable Array[MProperty] = null
-               for mprop in props do
-                       if not mtype.has_mproperty(mmodule, mprop) then continue
-                       if not mmodule.is_visible(mprop.intro_mclassdef.mmodule, mprop.visibility) then continue
-                       if res == null then
-                               res = mprop
-                       else
-                               var restype = res.intro_mclassdef.bound_mtype
-                               var mproptype = mprop.intro_mclassdef.bound_mtype
-                               if restype.is_subtype(mmodule, null, mproptype) then
-                                       # we keep res
-                               else if mproptype.is_subtype(mmodule, null, restype) then
-                                       res = mprop
-                               else
-                                       if ress == null then ress = new Array[MProperty]
-                                       ress.add(mprop)
-                               end
-                       end
-               end
-               if ress != null then
-                       var restype = res.intro_mclassdef.bound_mtype
-                       for mprop in ress do
-                               var mproptype = mprop.intro_mclassdef.bound_mtype
-                               if not restype.is_subtype(mmodule, null, mproptype) then
-                                       self.error(anode, "Ambigous property name '{name}' for {mtype}; conflict between {mprop.full_name} and {res.full_name}")
-                                       return null
-                               end
-                       end
-               end
-
-               self.try_get_mproperty_by_name2_cache[mmodule, mtype, name] = res
-               return res
-       end
-
-       private var try_get_mproperty_by_name2_cache: HashMap3[MModule, MType, String, nullable MProperty] = new HashMap3[MModule, MType, String, nullable MProperty]
-
-
-       # Alias for try_get_mproperty_by_name2(anode, mclassdef.mmodule, mclassdef.mtype, name)
-       fun try_get_mproperty_by_name(anode: ANode, mclassdef: MClassDef, name: String): nullable MProperty
-       do
-               return try_get_mproperty_by_name2(anode, mclassdef.mmodule, mclassdef.bound_mtype, name)
-       end
-
-       # The list of directories to search for top level modules
-       # The list is initially set with :
-       #   * the toolcontext --path option
-       #   * the NIT_PATH environment variable
-       #   * some heuristics including the NIT_DIR environment variable and the progname of the process
-       # Path can be added (or removed) by the client
-       var paths: Array[String] = new Array[String]
-
-       # Get a module by its short name; if required, the module is loaded, parsed and its hierarchies computed.
-       # If `mmodule' is set, then the module search starts from it up to the top level (see `paths');
-       # if `mmodule' is null then the module is searched in the top level only.
-       # If no module exists or there is a name conflict, then an error on `anode' is displayed and null is returned.
-       # FIXME: add a way to handle module name conflict
-       fun get_mmodule_by_name(anode: ANode, mmodule: nullable MModule, name: String): nullable MModule
-       do
-               var origmmodule = mmodule
-               var modules = model.get_mmodules_by_name(name)
-
-               var tries = new Array[String]
-
-               var lastmodule = mmodule
-               while mmodule != null do
-                       var dirname = mmodule.location.file.filename.dirname
-
-                       # Determine the owner
-                       var owner: nullable MModule
-                       if dirname.basename("") != mmodule.name then
-                               owner = mmodule.direct_owner
-                       else
-                               owner = mmodule
-                       end
-
-                       # First, try the already known nested modules
-                       if modules != null then
-                               for candidate in modules do
-                                       if candidate.direct_owner == owner then
-                                               return candidate
-                                       end
-                               end
-                       end
-
-                       # Second, try the directory to find a file
-                       var try_file = dirname + "/" + name + ".nit"
-                       tries.add try_file
-                       if try_file.file_exists then
-                               var res = self.load_module(owner, try_file.simplify_path)
-                               if res == null then return null # Forward error
-                               return res.mmodule.as(not null)
-                       end
-
-                       # Third, try if the requested module is itself an owner
-                       try_file = dirname + "/" + name + "/" + name + ".nit"
-                       if try_file.file_exists then
-                               var res = self.load_module(owner, try_file.simplify_path)
-                               if res == null then return null # Forward error
-                               return res.mmodule.as(not null)
-                       end
-
-                       lastmodule = mmodule
-                       mmodule = mmodule.direct_owner
-               end
-
-               if modules != null then
-                       for candidate in modules do
-                               if candidate.direct_owner == null then
-                                       return candidate
-                               end
-                       end
-               end
-
-               # Look at some known directories
-               var lookpaths = self.paths
-
-               # Look in the directory of the last module also (event if not in the path)
-               if lastmodule != null then
-                       var dirname = lastmodule.location.file.filename.dirname
-                       if dirname.basename("") == lastmodule.name then
-                               dirname = dirname.dirname
-                       end
-                       if not lookpaths.has(dirname) then
-                               lookpaths = lookpaths.to_a
-                               lookpaths.add(dirname)
-                       end
-               end
-
-               var candidate: nullable String = null
-               for dirname in lookpaths do
-                       var try_file = (dirname + "/" + name + ".nit").simplify_path
-                       tries.add try_file
-                       if try_file.file_exists then
-                               if candidate == null then
-                                       candidate = try_file
-                               else if candidate != try_file then
-                                       error(anode, "Error: conflicting module file for {name}: {candidate} {try_file}")
-                               end
-                       end
-                       try_file = (dirname + "/" + name + "/" + name + ".nit").simplify_path
-                       if try_file.file_exists then
-                               if candidate == null then
-                                       candidate = try_file
-                               else if candidate != try_file then
-                                       error(anode, "Error: conflicting module file for {name}: {candidate} {try_file}")
-                               end
-                       end
-               end
-               if candidate == null then
-                       if origmmodule != null then
-                               error(anode, "Error: cannot find module {name} from {origmmodule}. tried {tries.join(", ")}")
-                       else
-                               error(anode, "Error: cannot find module {name}. tried {tries.join(", ")}")
-                       end
-                       return null
-               end
-               var res = self.load_module(mmodule, candidate)
-               if res == null then return null # Forward error
-               return res.mmodule.as(not null)
-       end
-
-       # Try to load a module using a path.
-       # Display an error if there is a problem (IO / lexer / parser) and return null
-       # Note: usually, you do not need this method, use `get_mmodule_by_name` instead.
-       fun load_module(owner: nullable MModule, filename: String): nullable AModule
-       do
-               if not filename.file_exists then
-                       self.toolcontext.error(null, "Error: file {filename} not found.")
-                       return null
-               end
-
-               var x = if owner != null then owner.to_s else "."
-               self.toolcontext.info("load module {filename} in {x}", 2)
-
-               # Load the file
-               var file = new IFStream.open(filename)
-               var lexer = new Lexer(new SourceFile(filename, file))
-               var parser = new Parser(lexer)
-               var tree = parser.parse
-               file.close
-
-               # Handle lexer and parser error
-               var nmodule = tree.n_base
-               if nmodule == null then
-                       var neof = tree.n_eof
-                       assert neof isa AError
-                       error(neof, neof.message)
-                       return null
-               end
-
-               # Check the module name
-               var mod_name = filename.basename(".nit")
-               var decl = nmodule.n_moduledecl
-               if decl == null then
-                       #warning(nmodule, "Warning: Missing 'module' keyword") #FIXME: NOT YET FOR COMPATIBILITY
-               else
-                       var decl_name = decl.n_name.n_id.text
-                       if decl_name != mod_name then
-                               error(decl.n_name, "Error: module name missmatch; declared {decl_name} file named {mod_name}")
-                       end
-               end
-
-               # Create the module
-               var mmodule = new MModule(model, owner, mod_name, nmodule.location)
-               nmodule.mmodule = mmodule
-               nmodules.add(nmodule)
-               self.mmodule2nmodule[mmodule] = nmodule
-
-               build_module_importation(nmodule)
-
-               return nmodule
-       end
-
-       # Analysis the module importation and fill the module_importation_hierarchy
-       private fun build_module_importation(nmodule: AModule)
-       do
-               if nmodule.is_importation_done then return
-               nmodule.is_importation_done = true
-               var mmodule = nmodule.mmodule.as(not null)
-               var stdimport = true
-               var imported_modules = new Array[MModule]
-               for aimport in nmodule.n_imports do
-                       stdimport = false
-                       if not aimport isa AStdImport then
-                               continue
-                       end
-                       var mod_name = aimport.n_name.n_id.text
-                       var sup = self.get_mmodule_by_name(aimport.n_name, mmodule, mod_name)
-                       if sup == null then continue # Skip error
-                       imported_modules.add(sup)
-                       var mvisibility = aimport.n_visibility.mvisibility
-                       mmodule.set_visibility_for(sup, mvisibility)
-               end
-               if stdimport then
-                       var mod_name = "standard"
-                       var sup = self.get_mmodule_by_name(nmodule, null, mod_name)
-                       if sup != null then # Skip error
-                               imported_modules.add(sup)
-                               mmodule.set_visibility_for(sup, public_visibility)
-                       end
-               end
-               self.toolcontext.info("{mmodule} imports {imported_modules.join(", ")}", 3)
-               mmodule.set_imported_mmodules(imported_modules)
-       end
-
-       # All the loaded modules
-       var nmodules: Array[AModule] = new Array[AModule]
-
-       # Build the classes of all modules `nmodules'.
-       private fun build_all_classes
-       do
-               for nmodule in self.nmodules do
-                       build_classes(nmodule)
-               end
-       end
-
-       # Visit the AST and create the MClass objects
-       private fun build_a_mclass(nmodule: AModule, nclassdef: AClassdef)
-       do
-               var mmodule = nmodule.mmodule.as(not null)
-
-               var name: String
-               var nkind: nullable AClasskind
-               var mkind: MClassKind
-               var nvisibility: nullable AVisibility
-               var mvisibility: nullable MVisibility
-               var arity = 0
-               if nclassdef isa AStdClassdef then
-                       name = nclassdef.n_id.text
-                       nkind = nclassdef.n_classkind
-                       mkind = nkind.mkind
-                       nvisibility = nclassdef.n_visibility
-                       mvisibility = nvisibility.mvisibility
-                       arity = nclassdef.n_formaldefs.length
-               else if nclassdef isa ATopClassdef then
-                       name = "Object"
-                       nkind = null
-                       mkind = interface_kind
-                       nvisibility = null
-                       mvisibility = public_visibility
-               else if nclassdef isa AMainClassdef then
-                       name = "Sys"
-                       nkind = null
-                       mkind = concrete_kind
-                       nvisibility = null
-                       mvisibility = public_visibility
-               else
-                       abort
-               end
-
-               var mclass = try_get_mclass_by_name(nclassdef, mmodule, name)
-               if mclass == null then
-                       mclass = new MClass(mmodule, name, arity, mkind, mvisibility)
-                       #print "new class {mclass}"
-               else if nclassdef isa AStdClassdef and nmodule.mclass2nclassdef.has_key(mclass) then
-                       error(nclassdef, "Error: A class {name} is already defined at line {nmodule.mclass2nclassdef[mclass].location.line_start}.")
-                       return
-               else if nclassdef isa AStdClassdef and nclassdef.n_kwredef == null then
-                       error(nclassdef, "Redef error: {name} is an imported class. Add the redef keyword to refine it.")
-                       return
-               else if mclass.arity != arity then
-                       error(nclassdef, "Redef error: Formal parameter arity missmatch; got {arity}, expected {mclass.arity}.")
-                       return
-               else if nkind != null and mkind != concrete_kind and mclass.kind != mkind then
-                       error(nkind, "Error: refinement changed the kind from a {mclass.kind} to a {mkind}")
-               else if nvisibility != null and mvisibility != public_visibility and mclass.visibility != mvisibility then
-                       error(nvisibility, "Error: refinement changed the visibility from a {mclass.visibility} to a {mvisibility}")
-               end
-               nclassdef.mclass = mclass
-               nmodule.mclass2nclassdef[mclass] = nclassdef
-       end
-
-       # Visit the AST and create the MClassDef objects
-       private fun build_a_mclassdef(nmodule: AModule, nclassdef: AClassdef)
-       do
-               var mmodule = nmodule.mmodule.as(not null)
-               var objectclass = try_get_mclass_by_name(nmodule, mmodule, "Object")
-               var mclass = nclassdef.mclass
-               if mclass == null then return # Skip error
-               #var mclassdef = nclassdef.mclassdef.as(not null)
-
-               var names = new Array[String]
-               var bounds = new Array[MType]
-               if nclassdef isa AStdClassdef and mclass.arity > 0 then
-                       # Collect formal parameter names
-                       for i in [0..mclass.arity[ do
-                               var nfd = nclassdef.n_formaldefs[i]
-                               var ptname = nfd.n_id.text
-                               if names.has(ptname) then
-                                       error(nfd, "Error: A formal parameter type `{ptname}' already exists")
-                                       return
-                               end
-                               names.add(ptname)
-                       end
-
-                       # Revolve bound for formal parameter names
-                       for i in [0..mclass.arity[ do
-                               var nfd = nclassdef.n_formaldefs[i]
-                               var nfdt = nfd.n_type
-                               if nfdt != null then
-                                       var bound = resolve_mtype_unchecked(nclassdef, nfdt, false)
-                                       if bound == null then return # Forward error
-                                       if bound.need_anchor then
-                                               # No F-bounds!
-                                               error(nfd, "Error: Formal parameter type `{names[i]}' bounded with a formal parameter type")
-                                       else
-                                               bounds.add(bound)
-                                       end
-                               else if mclass.mclassdefs.is_empty then
-                                       # No bound, then implicitely bound by nullable Object
-                                       bounds.add(objectclass.mclass_type.as_nullable)
-                               else
-                                       # Inherit the bound
-                                       bounds.add(mclass.intro.bound_mtype.arguments[i])
-                               end
-                       end
-               end
-
-               var bound_mtype = mclass.get_mtype(bounds)
-               var mclassdef = new MClassDef(mmodule, bound_mtype, nclassdef.location, names)
-               nclassdef.mclassdef = mclassdef
-               self.mclassdef2nclassdef[mclassdef] = nclassdef
-
-               if mclassdef.is_intro then
-                       self.toolcontext.info("{mclassdef} introduces new {mclass.kind} {mclass.full_name}", 3)
-               else
-                       self.toolcontext.info("{mclassdef} refine {mclass.kind} {mclass.full_name}", 3)
-               end
-       end
-
-       # Visit the AST and set the super-types of the MClassdef objects
-       private fun collect_a_mclassdef_inheritance(nmodule: AModule, nclassdef: AClassdef)
-       do
-               var mmodule = nmodule.mmodule.as(not null)
-               var objectclass = try_get_mclass_by_name(nmodule, mmodule, "Object")
-               var mclass = nclassdef.mclass.as(not null)
-               var mclassdef = nclassdef.mclassdef.as(not null)
-
-               var specobject = true
-               var supertypes = new Array[MClassType]
-               if nclassdef isa AStdClassdef then
-                       for nsc in nclassdef.n_superclasses do
-                               specobject = false
-                               var ntype = nsc.n_type
-                               var mtype = resolve_mtype_unchecked(nclassdef, ntype, false)
-                               if mtype == null then continue # Skip because of error
-                               if not mtype isa MClassType then
-                                       error(ntype, "Error: supertypes cannot be a formal type")
-                                       return
-                               end
-                               supertypes.add mtype
-                               #print "new super : {mclass} < {mtype}"
-                       end
-               end
-               if specobject and mclass.name != "Object" and objectclass != null and mclassdef.is_intro then
-                       supertypes.add objectclass.mclass_type
-               end
-
-               mclassdef.set_supertypes(supertypes)
-               if not supertypes.is_empty then self.toolcontext.info("{mclassdef} new super-types: {supertypes.join(", ")}", 3)
-       end
-
-       # Check the validity of the specialization heirarchy
-       private fun check_supertypes(nmodule: AModule, nclassdef: AClassdef)
-       do
-               var mmodule = nmodule.mmodule.as(not null)
-               var objectclass = try_get_mclass_by_name(nmodule, mmodule, "Object")
-               var mclass = nclassdef.mclass.as(not null)
-               var mclassdef = nclassdef.mclassdef.as(not null)
-
-               for s in mclassdef.supertypes do
-                       if s.is_subtype(mmodule, mclassdef.bound_mtype, mclassdef.bound_mtype) then
-                               error(nclassdef, "Error: Inheritance loop for class {mclass} with type {s}")
-                       end
-               end
-       end
-
-       # Build the classes of the module `nmodule'.
-       # REQUIRE: classes of imported modules are already build. (let `build_all_classes' do the job)
-       private fun build_classes(nmodule: AModule)
-       do
-               # Force building recursively
-               if nmodule.build_classes_is_done then return
-               nmodule.build_classes_is_done = true
-               var mmodule = nmodule.mmodule.as(not null)
-               for imp in mmodule.in_importation.direct_greaters do
-
-                       build_classes(mmodule2nmodule[imp])
-               end
-
-               # Create all classes
-               for nclassdef in nmodule.n_classdefs do
-                       self.build_a_mclass(nmodule, nclassdef)
-               end
-
-               # Create all classdefs
-               for nclassdef in nmodule.n_classdefs do
-                       self.build_a_mclassdef(nmodule, nclassdef)
-               end
-
-               for nclassdef in nmodule.n_classdefs do
-                       if nclassdef.mclassdef == null then return # forward error
-               end
-
-               # Create inheritance on all classdefs
-               for nclassdef in nmodule.n_classdefs do
-                       self.collect_a_mclassdef_inheritance(nmodule, nclassdef)
-               end
-
-               # Create the mclassdef hierarchy
-               for nclassdef in nmodule.n_classdefs do
-                       var mclassdef = nclassdef.mclassdef.as(not null)
-                       mclassdef.add_in_hierarchy
-               end
-
-               # Check inheritance
-               for nclassdef in nmodule.n_classdefs do
-                       self.check_supertypes(nmodule, nclassdef)
-               end
-
-               # Check unchecked ntypes
-               for nclassdef in nmodule.n_classdefs do
-                       if nclassdef isa AStdClassdef then
-                               # check bound of formal parameter
-                               for nfd in  nclassdef.n_formaldefs do
-                                       var nfdt = nfd.n_type
-                                       if nfdt != null and nfdt.mtype != null then
-                                               var bound = resolve_mtype(nclassdef, nfdt)
-                                               if bound == null then return # Forward error
-                                       end
-                               end
-                               # check declared super types
-                               for nsc in nclassdef.n_superclasses do
-                                       var ntype = nsc.n_type
-                                       if ntype.mtype != null then
-                                               var mtype = resolve_mtype(nclassdef, ntype)
-                                               if mtype == null then return # Forward error
-                                       end
-                               end
-                       end
-
-               end
-
-               # TODO: Check that the super-class is not intrusive
-
-               # TODO: Check that the super-class is not already known (by transitivity)
-
-               for nclassdef in nmodule.n_classdefs do
-                       self.build_properties(nclassdef)
-               end
-       end
-
-       # Register the nmodule associated to each mmodule
-       # FIXME: why not refine the MModule class with a nullable attribute?
-       var mmodule2nmodule: HashMap[MModule, AModule] = new HashMap[MModule, AModule]
-       # Register the nclassdef associated to each mclassdef
-       # FIXME: why not refine the MClassDef class with a nullable attribute?
-       var mclassdef2nclassdef: HashMap[MClassDef, AClassdef] = new HashMap[MClassDef, AClassdef]
-       # Register the npropdef associated to each mpropdef
-       # FIXME: why not refine the MPropDef class with a nullable attribute?
-       var mpropdef2npropdef: HashMap[MPropDef, APropdef] = new HashMap[MPropDef, APropdef]
-
-       # Build the properties of `nclassdef'.
-       # REQUIRE: all superclasses are built.
-       private fun build_properties(nclassdef: AClassdef)
-       do
-               # Force building recursively
-               if nclassdef.build_properties_is_done then return
-               nclassdef.build_properties_is_done = true
-               var mclassdef = nclassdef.mclassdef.as(not null)
-               if mclassdef.in_hierarchy == null then return # Skip error
-               for superclassdef in mclassdef.in_hierarchy.direct_greaters do
-                       build_properties(mclassdef2nclassdef[superclassdef])
-               end
-
-               for npropdef in nclassdef.n_propdefs do
-                       npropdef.build_property(self, nclassdef)
-               end
-               for npropdef in nclassdef.n_propdefs do
-                       npropdef.build_signature(self, nclassdef)
-               end
-               for npropdef in nclassdef.n_propdefs do
-                       npropdef.check_signature(self, nclassdef)
-               end
-               process_default_constructors(nclassdef)
-       end
-
-       # Introduce or inherit default constructor
-       # This is the last part of `build_properties'.
-       private fun process_default_constructors(nclassdef: AClassdef)
-       do
-               var mclassdef = nclassdef.mclassdef.as(not null)
-
-               # Are we a refinement
-               if not mclassdef.is_intro then return
-
-               # Is the class forbid constructors?
-               if not mclassdef.mclass.kind.need_init then return
-
-               # Is there already a constructor defined?
-               for mpropdef in mclassdef.mpropdefs do
-                       if not mpropdef isa MMethodDef then continue
-                       if mpropdef.mproperty.is_init then return
-               end
-
-               if not nclassdef isa AStdClassdef then return
-
-               var mmodule = nclassdef.mclassdef.mmodule
-               # Do we inherit for a constructor?
-               var combine = new Array[MMethod]
-               var inhc: nullable MClass = null
-               for st in mclassdef.supertypes do
-                       var c = st.mclass
-                       if not c.kind.need_init then continue
-                       st = st.anchor_to(mmodule, nclassdef.mclassdef.bound_mtype)
-                       var candidate = self.try_get_mproperty_by_name2(nclassdef, mmodule, st, "init").as(nullable MMethod)
-                       if candidate != null and candidate.intro.msignature.arity == 0 then
-                               combine.add(candidate)
-                               continue
-                       end
-                       var inhc2 = c.inherit_init_from
-                       if inhc2 == null then inhc2 = c
-                       if inhc2 == inhc then continue
-                       if inhc != null then
-                               self.error(nclassdef, "Error: Cannot provide a defaut constructor: conflict for {inhc} and {c}")
-                       else
-                               inhc = inhc2
-                       end
-               end
-               if combine.is_empty and inhc != null then
-                       # TODO: actively inherit the consturctor
-                       self.toolcontext.info("{mclassdef} inherits all constructors from {inhc}", 3)
-                       mclassdef.mclass.inherit_init_from = inhc
-                       return
-               end
-               if not combine.is_empty and inhc != null then
-                       self.error(nclassdef, "Error: Cannot provide a defaut constructor: conflict for {combine.join(", ")} and {inhc}")
-                       return
-               end
-
-               if not combine.is_empty then
-                       nclassdef.super_inits = combine
-                       var mprop = new MMethod(mclassdef, "init", mclassdef.mclass.visibility)
-                       var mpropdef = new MMethodDef(mclassdef, mprop, nclassdef.location)
-                       var mparameters = new Array[MParameter]
-                       var msignature = new MSignature(mparameters, null)
-                       mpropdef.msignature = msignature
-                       mprop.is_init = true
-                       nclassdef.mfree_init = mpropdef
-                       self.toolcontext.info("{mclassdef} gets a free empty constructor {mpropdef}{msignature}", 3)
-                       return
-               end
-
-               # Collect undefined attributes
-               var mparameters = new Array[MParameter]
-               for npropdef in nclassdef.n_propdefs do
-                       if npropdef isa AAttrPropdef and npropdef.n_expr == null then
-                               if npropdef.mpropdef == null then return # Skip broken attribute
-                               var paramname = npropdef.mpropdef.mproperty.name.substring_from(1)
-                               var ret_type = npropdef.mpropdef.static_mtype
-                               if ret_type == null then return
-                               var mparameter = new MParameter(paramname, ret_type, false)
-                               mparameters.add(mparameter)
-                       end
-               end
-
-               var mprop = new MMethod(mclassdef, "init", mclassdef.mclass.visibility)
-               var mpropdef = new MMethodDef(mclassdef, mprop, nclassdef.location)
-               var msignature = new MSignature(mparameters, null)
-               mpropdef.msignature = msignature
-               mprop.is_init = true
-               nclassdef.mfree_init = mpropdef
-               self.toolcontext.info("{mclassdef} gets a free constructor for attributes {mpropdef}{msignature}", 3)
-       end
-
-       # Return the static type associated to the node `ntype'.
-       # `classdef' is the context where the call is made (used to understand formal types)
-       # The mmodule used as context is `nclassdef.mmodule'
-       # In case of problem, an error is displayed on `ntype' and null is returned.
-       # FIXME: the name "resolve_mtype" is awful
-       fun resolve_mtype_unchecked(nclassdef: AClassdef, ntype: AType, with_virtual: Bool): nullable MType
-       do
-               var name = ntype.n_id.text
-               var mclassdef = nclassdef.mclassdef
-               var mmodule = nclassdef.parent.as(AModule).mmodule.as(not null)
-               var res: MType
-
-               # Check virtual type
-               if mclassdef != null and with_virtual then
-                       var prop = try_get_mproperty_by_name(ntype, mclassdef, name).as(nullable MVirtualTypeProp)
-                       if prop != null then
-                               if not ntype.n_types.is_empty then
-                                       error(ntype, "Type error: formal type {name} cannot have formal parameters.")
-                               end
-                               res = prop.mvirtualtype
-                               if ntype.n_kwnullable != null then res = res.as_nullable
-                               ntype.mtype = res
-                               return res
-                       end
-               end
-
-               # Check parameter type
-               if mclassdef != null and mclassdef.parameter_names.has(name) then
-                       if not ntype.n_types.is_empty then
-                               error(ntype, "Type error: formal type {name} cannot have formal parameters.")
-                       end
-                       for i in [0..mclassdef.parameter_names.length[ do
-                               if mclassdef.parameter_names[i] == name then
-                                       res = mclassdef.mclass.mclass_type.arguments[i]
-                                       if ntype.n_kwnullable != null then res = res.as_nullable
-                                       ntype.mtype = res
-                                       return res
-                               end
-                       end
-                       abort
-               end
-
-               # Check class
-               var mclass = try_get_mclass_by_name(ntype, mmodule, name)
-               if mclass != null then
-                       var arity = ntype.n_types.length
-                       if arity != mclass.arity then
-                               if arity == 0 then
-                                       error(ntype, "Type error: '{name}' is a generic class.")
-                               else if mclass.arity == 0 then
-                                       error(ntype, "Type error: '{name}' is not a generic class.")
-                               else
-                                       error(ntype, "Type error: '{name}' has {mclass.arity} parameters ({arity} are provided).")
-                               end
-                               return null
-                       end
-                       if arity == 0 then
-                               res = mclass.mclass_type
-                               if ntype.n_kwnullable != null then res = res.as_nullable
-                               ntype.mtype = res
-                               return res
-                       else
-                               var mtypes = new Array[MType]
-                               for nt in ntype.n_types do
-                                       var mt = resolve_mtype_unchecked(nclassdef, nt, with_virtual)
-                                       if mt == null then return null # Forward error
-                                       mtypes.add(mt)
-                               end
-                               res = mclass.get_mtype(mtypes)
-                               if ntype.n_kwnullable != null then res = res.as_nullable
-                               ntype.mtype = res
-                               return res
-                       end
-               end
-
-               # If everything fail, then give up :(
-               error(ntype, "Type error: class {name} not found in module {mmodule}.")
-               return null
-       end
-
-       # Return the static type associated to the node `ntype'.
-       # `classdef' is the context where the call is made (used to understand formal types)
-       # The mmodule used as context is `nclassdef.mmodule'
-       # In case of problem, an error is displayed on `ntype' and null is returned.
-       # FIXME: the name "resolve_mtype" is awful
-       fun resolve_mtype(nclassdef: AClassdef, ntype: AType): nullable MType
-       do
-               var mtype = ntype.mtype
-               if mtype == null then mtype = resolve_mtype_unchecked(nclassdef, ntype, true)
-               if mtype == null then return null # Forward error
-
-               if ntype.checked_mtype then return mtype
-               if mtype isa MGenericType then
-                       var mmodule = nclassdef.parent.as(AModule).mmodule.as(not null)
-                       var mclassdef = nclassdef.mclassdef
-                       var mclass = mtype.mclass
-                       for i in [0..mclass.arity[ do
-                               var bound = mclass.intro.bound_mtype.arguments[i]
-                               var nt = ntype.n_types[i]
-                               var mt = resolve_mtype(nclassdef, nt)
-                               if mt == null then return null # forward error
-                               if not mt.is_subtype(mmodule, mclassdef.bound_mtype, bound) then
-                                       error(nt, "Type error: expected {bound}, got {mt}")
-                                       return null
-                               end
-                       end
-               end
-               ntype.checked_mtype = true
-               return mtype
-       end
-
-       # Helper function to display an error on a node.
-       # Alias for `self.toolcontext.error(n.hot_location, text)'
-       fun error(n: ANode, text: String)
-       do
-               self.toolcontext.error(n.hot_location, text)
-       end
-
-       # Helper function to display a warning on a node.
-       # Alias for: `self.toolcontext.warning(n.hot_location, text)'
-       fun warning(n: ANode, text: String)
-       do
-               self.toolcontext.warning(n.hot_location, text)
-       end
-
-       # Force to get the primitive method named `name' on the type `recv' or do a fatal error on `n'
-       fun force_get_primitive_method(n: ANode, name: String, recv: MType, mmodule: MModule): MMethod
-       do
-               var res = mmodule.try_get_primitive_method(name, recv)
-               if res == null then
-                       self.toolcontext.fatal_error(n.hot_location, "Fatal Error: {recv} must have a property named {name}.")
-                       abort
-               end
-               return res
-       end
-end
-
-redef class AModule
-       # The associated MModule once build by a `ModelBuilder'
-       var mmodule: nullable MModule
-       # Flag that indicate if the importation is already completed
-       var is_importation_done: Bool = false
-       # Flag that indicate if the class and prop building is already completed
-       var build_classes_is_done: Bool = false
-       # What is the AClassdef associated to a MClass?
-       # Used to check multiple definition of a class.
-       var mclass2nclassdef: Map[MClass, AClassdef] = new HashMap[MClass, AClassdef]
-
-end
-
-redef class MClass
-       # The class whose self inherit all the constructors.
-       # FIXME: this is needed to implement the crazy constructor mixin thing of the of old compiler. We need to think what to do with since this cannot stay in the modelbuilder
-       var inherit_init_from: nullable MClass = null
-end
-
-redef class AClassdef
-       # The associated MClass once build by a `ModelBuilder'
-       var mclass: nullable MClass
-       # The associated MClassDef once build by a `ModelBuilder'
-       var mclassdef: nullable MClassDef
-       var build_properties_is_done: Bool = false
-       # The list of super-constructor to call at the start of the free constructor
-       # FIXME: this is needed to implement the crazy constructor thing of the of old compiler. We need to think what to do with since this cannot stay in the modelbuilder
-       var super_inits: nullable Collection[MMethod] = null
-
-       # The free init (implicitely constructed by the class if required)
-       var mfree_init: nullable MMethodDef = null
-
-       # What is the APropdef associated to a MProperty?
-       # Used to check multiple definition of a property.
-       var mprop2npropdef: Map[MProperty, APropdef] = new HashMap[MProperty, APropdef]
-end
-
-redef class AClasskind
-       # The class kind associated with the AST node class
-       private fun mkind: MClassKind is abstract
-end
-redef class AConcreteClasskind
-       redef fun mkind do return concrete_kind
-end
-redef class AAbstractClasskind
-       redef fun mkind do return abstract_kind
-end
-redef class AInterfaceClasskind
-       redef fun mkind do return interface_kind
-end
-redef class AEnumClasskind
-       redef fun mkind do return enum_kind
-end
-redef class AExternClasskind
-       redef fun mkind do return extern_kind
-end
-
-redef class AVisibility
-       # The visibility level associated with the AST node class
-       private fun mvisibility: MVisibility is abstract
-end
-redef class AIntrudeVisibility
-       redef fun mvisibility do return intrude_visibility
-end
-redef class APublicVisibility
-       redef fun mvisibility do return public_visibility
-end
-redef class AProtectedVisibility
-       redef fun mvisibility do return protected_visibility
-end
-redef class APrivateVisibility
-       redef fun mvisibility do return private_visibility
-end
-
-redef class AType
-       # The mtype associated to the node
-       var mtype: nullable MType = null
-
-       # Is the mtype a valid one?
-       var checked_mtype: Bool = false
-end
-
-#
-
-redef class Prod
-       # Join the text of all tokens
-       # Used to get the 'real name' of method definitions.
-       fun collect_text: String
-       do
-               var v = new TextCollectorVisitor
-               v.enter_visit(self)
-               assert v.text != ""
-               return v.text
-       end
-end
-
-private class TextCollectorVisitor
-       super Visitor
-       var text: String = ""
-       redef fun visit(n)
-       do
-               if n isa Token then text += n.text
-               n.visit_all(self)
-       end
-end
-
-redef class APropdef
-       private fun build_property(modelbuilder: ModelBuilder, nclassdef: AClassdef)
-       do
-       end
-       private fun build_signature(modelbuilder: ModelBuilder, nclassdef: AClassdef)
-       do
-       end
-       private fun check_signature(modelbuilder: ModelBuilder, nclassdef: AClassdef)
-       do
-       end
-       private fun new_property_visibility(modelbuilder: ModelBuilder, nclassdef: AClassdef, nvisibility: nullable AVisibility): MVisibility
-       do
-               var mvisibility = public_visibility
-               if nvisibility != null then mvisibility = nvisibility.mvisibility
-               if nclassdef.mclassdef.mclass.visibility == private_visibility then
-                       if mvisibility == protected_visibility then
-                               assert nvisibility != null
-                               modelbuilder.error(nvisibility, "Error: The only legal visibility for properties in a private class is private.")
-                       else if mvisibility == private_visibility then
-                               assert nvisibility != null
-                               # Not yet
-                               # modelbuilder.warning(nvisibility, "Warning: private is unrequired since the only legal visibility for properties in a private class is private.")
-                       end
-                       mvisibility = private_visibility
-               end
-               return mvisibility
-       end
-
-       private fun check_redef_property_visibility(modelbuilder: ModelBuilder, nclassdef: AClassdef, nvisibility: nullable AVisibility, mprop: MProperty)
-       do
-               if nvisibility == null then return
-               var mvisibility = nvisibility.mvisibility
-               if mvisibility != mprop.visibility and mvisibility != public_visibility then
-                               modelbuilder.error(nvisibility, "Error: redefinition changed the visibility from a {mprop.visibility} to a {mvisibility}")
-               end
-       end
-
-       private fun check_redef_keyword(modelbuilder: ModelBuilder, nclassdef: AClassdef, kwredef: nullable Token, need_redef: Bool, mprop: MProperty): Bool
-       do
-               if nclassdef.mprop2npropdef.has_key(mprop) then
-                       modelbuilder.error(self, "Error: A property {mprop} is already defined in class {nclassdef.mclassdef.mclass}.")
-                       return false
-               end
-               if kwredef == null then
-                       if need_redef then
-                               modelbuilder.error(self, "Redef error: {nclassdef.mclassdef.mclass}::{mprop.name} is an inherited property. To redefine it, add the redef keyword.")
-                               return false
-                       end
+               option_context.add_option(opt_ignore_visibility)
+       end
+
+       # Combine module to make a single one if required.
+       fun make_main_module(mmodules: Array[MModule]): MModule
+       do
+               assert not mmodules.is_empty
+               var mainmodule
+               # We need a main module, so we build it by importing all modules
+               mainmodule = new MModule(modelbuilder.model, null, mmodules.first.name + "-m", new Location(mmodules.first.location.file, 0, 0, 0, 0))
+               mainmodule.is_fictive = true
+               mainmodule.first_real_mmodule = mmodules.first.first_real_mmodule
+               mainmodule.set_imported_mmodules(mmodules)
+               modelbuilder.apply_conditional_importations(mainmodule)
+               if mainmodule.in_importation.direct_greaters.length == 1 and mainmodule.in_importation.direct_greaters.first == mmodules.first then
+                       # Drop the fictive module if not needed
+                       mainmodule = mmodules.first
                else
-                       if not need_redef then
-                               modelbuilder.error(self, "Error: No property {nclassdef.mclassdef.mclass}::{mprop.name} is inherited. Remove the redef keyword to define a new property.")
-                               return false
-                       end
+                       # Or else run phases on it
+                       modelbuilder.run_phases
                end
-               return true
+               return mainmodule
        end
 
-end
-
-redef class ASignature
-       # Is the model builder has correctly visited the signature
-       var is_visited = false
-       # Names of parameters from the AST
-       # REQUIRE: is_visited
-       var param_names = new Array[String]
-       # Types of parameters from the AST
-       # REQUIRE: is_visited
-       var param_types = new Array[MType]
-       # Rank of the vararg (of -1 if none)
-       # REQUIRE: is_visited
-       var vararg_rank: Int = -1
-       # Return type
-       var ret_type: nullable MType = null
-
-       # Visit and fill information about a signature
-       private fun visit_signature(modelbuilder: ModelBuilder, nclassdef: AClassdef): Bool
+       # Run `process_mainmodule` on all phases
+       fun run_global_phases(mmodules: Array[MModule])
        do
-               var param_names = self.param_names
-               var param_types = self.param_types
-               for np in self.n_params do
-                       param_names.add(np.n_id.text)
-                       var ntype = np.n_type
-                       if ntype != null then
-                               var mtype = modelbuilder.resolve_mtype(nclassdef, ntype)
-                               if mtype == null then return false # Skip error
-                               for i in [0..param_names.length-param_types.length[ do
-                                       param_types.add(mtype)
-                               end
-                               if np.n_dotdotdot != null then
-                                       if self.vararg_rank != -1 then
-                                               modelbuilder.error(np, "Error: {param_names[self.vararg_rank]} is already a vararg")
-                                               return false
-                                       else
-                                               self.vararg_rank = param_names.length - 1
-                                       end
-                               end
+               if not mmodules.is_empty then
+                       var mainmodule = make_main_module(mmodules)
+                       for phase in phases_list do
+                               if phase.disabled then continue
+                               phase.process_mainmodule(mainmodule, mmodules)
                        end
                end
-               var ntype = self.n_type
-               if ntype != null then
-                       self.ret_type = modelbuilder.resolve_mtype(nclassdef, ntype)
-                       if self.ret_type == null then return false # Skip errir
-               end
 
-               for nclosure in self.n_closure_decls do
-                       if not nclosure.n_signature.visit_signature(modelbuilder, nclassdef) then return false
-               end
-
-               self.is_visited = true
-               return true
-       end
-
-       # Build a visited signature
-       fun build_signature(modelbuilder: ModelBuilder, nclassdef: AClassdef): nullable MSignature
-       do
-               if param_names.length != param_types.length then
-                       # Some parameters are typed, other parameters are not typed.
-                       modelbuilder.error(self.n_params[param_types.length], "Error: Untyped parameter `{param_names[param_types.length]}'.")
-                       return null
-               end
-
-               var mparameters = new Array[MParameter]
-               for i in [0..param_names.length[ do
-                       var mparameter = new MParameter(param_names[i], param_types[i], i == vararg_rank)
-                       mparameters.add(mparameter)
-               end
-
-               var msignature = new MSignature(mparameters, ret_type)
-               return msignature
+               check_errors
+               errors_info
        end
 end
 
-redef class AMethPropdef
-       # The associated MMethodDef once build by a `ModelBuilder'
-       var mpropdef: nullable MMethodDef
-
-       # The associated super init if any
-       var super_init: nullable MMethod
-       redef fun build_property(modelbuilder, nclassdef)
-       do
-               var is_init = self isa AInitPropdef
-               var mclassdef = nclassdef.mclassdef.as(not null)
-               var name: String
-               var amethodid = self.n_methid
-               var name_node: ANode
-               if amethodid == null then
-                       if self isa AMainMethPropdef then
-                               name = "main"
-                               name_node = self
-                       else if self isa AConcreteInitPropdef then
-                               name = "init"
-                               name_node = self.n_kwinit
-                       else if self isa AExternInitPropdef then
-                               name = "init"
-                               name_node = self.n_kwnew
-                       else
-                               abort
-                       end
-               else if amethodid isa AIdMethid then
-                       name = amethodid.n_id.text
-                       name_node = amethodid
-               else
-                       # operator, bracket or assign
-                       name = amethodid.collect_text
-                       name_node = amethodid
-
-                       if name == "-" and self.n_signature.n_params.length == 0 then
-                               name = "unary -"
-                       end
-               end
-
-               var mprop: nullable MMethod = null
-               if not is_init or n_kwredef != null then mprop = modelbuilder.try_get_mproperty_by_name(name_node, mclassdef, name).as(nullable MMethod)
-               if mprop == null then
-                       var mvisibility = new_property_visibility(modelbuilder, nclassdef, self.n_visibility)
-                       mprop = new MMethod(mclassdef, name, mvisibility)
-                       mprop.is_init = is_init
-                       mprop.is_new = self isa AExternInitPropdef
-                       if not self.check_redef_keyword(modelbuilder, nclassdef, n_kwredef, false, mprop) then return
-               else
-                       if n_kwredef == null then
-                               if self isa AMainMethPropdef then
-                                       # no warning
-                               else
-                                       if not self.check_redef_keyword(modelbuilder, nclassdef, n_kwredef, true, mprop) then return
-                               end
-                       end
-                       check_redef_property_visibility(modelbuilder, nclassdef, self.n_visibility, mprop)
-               end
-               nclassdef.mprop2npropdef[mprop] = self
-
-               var mpropdef = new MMethodDef(mclassdef, mprop, self.location)
-
-               self.mpropdef = mpropdef
-               modelbuilder.mpropdef2npropdef[mpropdef] = self
-               if mpropdef.is_intro then
-                       modelbuilder.toolcontext.info("{mpropdef} introduces new method {mprop.full_name}", 3)
-               else
-                       modelbuilder.toolcontext.info("{mpropdef} redefines method {mprop.full_name}", 3)
-               end
-       end
-
-       redef fun build_signature(modelbuilder, nclassdef)
-       do
-               var mpropdef = self.mpropdef
-               if mpropdef == null then return # Error thus skiped
-               var mmodule = mpropdef.mclassdef.mmodule
-               var nsig = self.n_signature
-
-               # Retrieve info from the signature AST
-               var param_names = new Array[String] # Names of parameters from the AST
-               var param_types = new Array[MType] # Types of parameters from the AST
-               var vararg_rank = -1
-               var ret_type: nullable MType = null # Return type from the AST
-               if nsig != null then
-                       if not nsig.visit_signature(modelbuilder, nclassdef) then return
-                       param_names = nsig.param_names
-                       param_types = nsig.param_types
-                       vararg_rank = nsig.vararg_rank
-                       ret_type = nsig.ret_type
-               end
-
-               # Look for some signature to inherit
-               # FIXME: do not inherit from the intro, but from the most specific
-               var msignature: nullable MSignature = null
-               if not mpropdef.is_intro then
-                       msignature = mpropdef.mproperty.intro.msignature
-                       if msignature == null then return # Skip error
-
-                       # Check inherited signature arity
-                       if param_names.length != msignature.arity then
-                               var node: ANode
-                               if nsig != null then node = nsig else node = self
-                               modelbuilder.error(node, "Redef error: {mpropdef} redefines {mpropdef.mproperty.intro} with {param_names.length} parameter(s), {msignature.arity} expected. Signature is {mpropdef}{msignature}")
-                               return
-                       end
-               else if mpropdef.mproperty.is_init then
-                       # FIXME UGLY: inherit signature from a super-constructor
-                       for msupertype in nclassdef.mclassdef.supertypes do
-                               msupertype = msupertype.anchor_to(mmodule, nclassdef.mclassdef.bound_mtype)
-                               var candidate = modelbuilder.try_get_mproperty_by_name2(self, mmodule, msupertype, mpropdef.mproperty.name)
-                               if candidate != null then
-                                       if msignature == null then
-                                               msignature = candidate.intro.as(MMethodDef).msignature
-                                       end
-                               end
-                       end
-               end
-
-
-               # Inherit the signature
-               if msignature != null and param_names.length != param_types.length and param_names.length == msignature.arity and param_types.length == 0 then
-                       # Parameters are untyped, thus inherit them
-                       param_types = new Array[MType]
-                       for mparameter in msignature.mparameters do
-                               param_types.add(mparameter.mtype)
-                       end
-                       vararg_rank = msignature.vararg_rank
-               end
-               if msignature != null and ret_type == null then
-                       ret_type = msignature.return_mtype
-               end
-
-               if param_names.length != param_types.length then
-                       # Some parameters are typed, other parameters are not typed.
-                       modelbuilder.error(nsig.n_params[param_types.length], "Error: Untyped parameter `{param_names[param_types.length]}'.")
-                       return
-               end
-
-               var mparameters = new Array[MParameter]
-               for i in [0..param_names.length[ do
-                       var mparameter = new MParameter(param_names[i], param_types[i], i == vararg_rank)
-                       mparameters.add(mparameter)
-               end
-
-               msignature = new MSignature(mparameters, ret_type)
-               mpropdef.msignature = msignature
-
-               if nsig != null then
-                       for nclosure in nsig.n_closure_decls do
-                               var clos_signature = nclosure.n_signature.build_signature(modelbuilder, nclassdef)
-                               if clos_signature == null then return
-                               var mparameter = new MParameter(nclosure.n_id.text, clos_signature, false)
-                               msignature.mclosures.add(mparameter)
-                       end
-               end
-
-       end
-
-       redef fun check_signature(modelbuilder, nclassdef)
-       do
-               var mpropdef = self.mpropdef
-               if mpropdef == null then return # Error thus skiped
-               var mmodule = mpropdef.mclassdef.mmodule
-               var nsig = self.n_signature
-               var mysignature = self.mpropdef.msignature
-               if mysignature == null then return # Error thus skiped
-
-               # Lookup for signature in the precursor
-               # FIXME all precursors should be considered
-               if not mpropdef.is_intro then
-                       var msignature = mpropdef.mproperty.intro.msignature
-                       if msignature == null then return
-
-                       var precursor_ret_type = msignature.return_mtype
-                       var ret_type = mysignature.return_mtype
-                       if ret_type != null and precursor_ret_type == null then
-                               modelbuilder.error(nsig.n_type.as(not null), "Redef Error: {mpropdef.mproperty} is a procedure, not a function.")
-                               return
-                       end
-
-                       if mysignature.arity > 0 then
-                               # Check parameters types
-                               for i in [0..mysignature.arity[ do
-                                       var myt = mysignature.mparameters[i].mtype
-                                       var prt = msignature.mparameters[i].mtype
-                                       if not myt.is_subtype(mmodule, nclassdef.mclassdef.bound_mtype, prt) and
-                                                       not prt.is_subtype(mmodule, nclassdef.mclassdef.bound_mtype, myt) then
-                                               modelbuilder.error(nsig.n_params[i], "Redef Error: Wrong type for parameter `{mysignature.mparameters[i].name}'. found {myt}, expected {prt}.")
-                                       end
-                               end
-                       end
-                       if precursor_ret_type != null then
-                               if ret_type == null then
-                                       # Inherit the return type
-                                       ret_type = precursor_ret_type
-                               else if not ret_type.is_subtype(mmodule, nclassdef.mclassdef.bound_mtype, precursor_ret_type) then
-                                       modelbuilder.error(nsig.n_type.as(not null), "Redef Error: Wrong return type. found {ret_type}, expected {precursor_ret_type}.")
-                               end
-                       end
-               end
-       end
+redef class Phase
+       # Specific action to execute on the whole program.
+       # Called by the `ToolContext::run_global_phases`.
+       #
+       # `mainmodule` is the main module of the program.
+       # It could be an implicit module (called like the first given_mmodules).
+       #
+       # `given_modules` is the list of explicitely requested modules.
+       # from the command-line for instance.
+       #
+       # REQUIRE: `not given_modules.is_empty`
+       # REQUIRE: `(given_modules.length == 1) == (mainmodule == given_modules.first)`
+       #
+       # @toimplement
+       fun process_mainmodule(mainmodule: MModule, given_mmodules: SequenceRead[MModule]) do end
 end
 
-redef class AAttrPropdef
-       # The associated MAttributeDef once build by a `ModelBuilder'
-       var mpropdef: nullable MAttributeDef
-       # The associated getter (read accessor) if any
-       var mreadpropdef: nullable MMethodDef
-       # The associated setter (write accessor) if any
-       var mwritepropdef: nullable MMethodDef
-       redef fun build_property(modelbuilder, nclassdef)
-       do
-               var mclassdef = nclassdef.mclassdef.as(not null)
-               var mclass = mclassdef.mclass
-
-               var name: String
-               if self.n_id != null then
-                       name = self.n_id.text
-               else
-                       name = self.n_id2.text
-               end
-
-               if mclass.kind == interface_kind or mclassdef.mclass.kind == enum_kind then
-                       modelbuilder.error(self, "Error: Attempt to define attribute {name} in the interface {mclass}.")
-               else if mclass.kind == enum_kind then
-                       modelbuilder.error(self, "Error: Attempt to define attribute {name} in the enum class {mclass}.")
-               else if mclass.kind == extern_kind then
-                       modelbuilder.error(self, "Error: Attempt to define attribute {name} in the extern class {mclass}.")
-               end
-
-               var nid = self.n_id
-               if nid != null then
-                       # Old attribute style
-                       var mprop = modelbuilder.try_get_mproperty_by_name(nid, mclassdef, name)
-                       if mprop == null then
-                               var mvisibility = new_property_visibility(modelbuilder, nclassdef, self.n_visibility)
-                               mprop = new MAttribute(mclassdef, name, mvisibility)
-                               if not self.check_redef_keyword(modelbuilder, nclassdef, self.n_kwredef, false, mprop) then return
-                       else
-                               assert mprop isa MAttribute
-                               check_redef_property_visibility(modelbuilder, nclassdef, self.n_visibility, mprop)
-                               if not self.check_redef_keyword(modelbuilder, nclassdef, self.n_kwredef, true, mprop) then return
-                       end
-                       nclassdef.mprop2npropdef[mprop] = self
-
-                       var mpropdef = new MAttributeDef(mclassdef, mprop, self.location)
-                       self.mpropdef = mpropdef
-                       modelbuilder.mpropdef2npropdef[mpropdef] = self
-
-                       var nreadable = self.n_readable
-                       if nreadable != null then
-                               var readname = name.substring_from(1)
-                               var mreadprop = modelbuilder.try_get_mproperty_by_name(nid, mclassdef, readname).as(nullable MMethod)
-                               if mreadprop == null then
-                                       var mvisibility = new_property_visibility(modelbuilder, nclassdef, nreadable.n_visibility)
-                                       mreadprop = new MMethod(mclassdef, readname, mvisibility)
-                                       if not self.check_redef_keyword(modelbuilder, nclassdef, nreadable.n_kwredef, false, mreadprop) then return
-                               else
-                                       if not self.check_redef_keyword(modelbuilder, nclassdef, nreadable.n_kwredef, true, mreadprop) then return
-                                       check_redef_property_visibility(modelbuilder, nclassdef, nreadable.n_visibility, mreadprop)
-                               end
-                               nclassdef.mprop2npropdef[mreadprop] = self
-
-                               var mreadpropdef = new MMethodDef(mclassdef, mreadprop, self.location)
-                               self.mreadpropdef = mreadpropdef
-                               modelbuilder.mpropdef2npropdef[mreadpropdef] = self
-                       end
-
-                       var nwritable = self.n_writable
-                       if nwritable != null then
-                               var writename = name.substring_from(1) + "="
-                               var mwriteprop = modelbuilder.try_get_mproperty_by_name(nid, mclassdef, writename).as(nullable MMethod)
-                               if mwriteprop == null then
-                                       var mvisibility = new_property_visibility(modelbuilder, nclassdef, nwritable.n_visibility)
-                                       mwriteprop = new MMethod(mclassdef, writename, mvisibility)
-                                       if not self.check_redef_keyword(modelbuilder, nclassdef, nwritable.n_kwredef, false, mwriteprop) then return
-                               else
-                                       if not self.check_redef_keyword(modelbuilder, nclassdef, nwritable.n_kwredef, true, mwriteprop) then return
-                                       check_redef_property_visibility(modelbuilder, nclassdef, nwritable.n_visibility, mwriteprop)
-                               end
-                               nclassdef.mprop2npropdef[mwriteprop] = self
-
-                               var mwritepropdef = new MMethodDef(mclassdef, mwriteprop, self.location)
-                               self.mwritepropdef = mwritepropdef
-                               modelbuilder.mpropdef2npropdef[mwritepropdef] = self
-                       end
-               else
-                       # New attribute style
-                       var nid2 = self.n_id2.as(not null)
-                       var mprop = new MAttribute(mclassdef, "@" + name, none_visibility)
-                       var mpropdef = new MAttributeDef(mclassdef, mprop, self.location)
-                       self.mpropdef = mpropdef
-                       modelbuilder.mpropdef2npropdef[mpropdef] = self
-
-                       var readname = name
-                       var mreadprop = modelbuilder.try_get_mproperty_by_name(nid2, mclassdef, readname).as(nullable MMethod)
-                       if mreadprop == null then
-                               var mvisibility = new_property_visibility(modelbuilder, nclassdef, self.n_visibility)
-                               mreadprop = new MMethod(mclassdef, readname, mvisibility)
-                               if not self.check_redef_keyword(modelbuilder, nclassdef, n_kwredef, false, mreadprop) then return
-                       else
-                               if not self.check_redef_keyword(modelbuilder, nclassdef, n_kwredef, true, mreadprop) then return
-                               check_redef_property_visibility(modelbuilder, nclassdef, self.n_visibility, mreadprop)
-                       end
-                       nclassdef.mprop2npropdef[mreadprop] = self
-
-                       var mreadpropdef = new MMethodDef(mclassdef, mreadprop, self.location)
-                       self.mreadpropdef = mreadpropdef
-                       modelbuilder.mpropdef2npropdef[mreadpropdef] = self
 
-                       var writename = name + "="
-                       var nwritable = self.n_writable
-                       var mwriteprop = modelbuilder.try_get_mproperty_by_name(nid2, mclassdef, writename).as(nullable MMethod)
-                       var nwkwredef: nullable Token = null
-                       if nwritable != null then nwkwredef = nwritable.n_kwredef
-                       if mwriteprop == null then
-                               var mvisibility
-                               if nwritable != null then
-                                       mvisibility = new_property_visibility(modelbuilder, nclassdef, nwritable.n_visibility)
-                               else
-                                       mvisibility = private_visibility
-                               end
-                               mwriteprop = new MMethod(mclassdef, writename, mvisibility)
-                               if not self.check_redef_keyword(modelbuilder, nclassdef, nwkwredef, false, mwriteprop) then return
-                       else
-                               if not self.check_redef_keyword(modelbuilder, nclassdef, nwkwredef, true, mwriteprop) then return
-                               if nwritable != null then
-                                       check_redef_property_visibility(modelbuilder, nclassdef, nwritable.n_visibility, mwriteprop)
-                               end
-                       end
-                       nclassdef.mprop2npropdef[mwriteprop] = self
-
-                       var mwritepropdef = new MMethodDef(mclassdef, mwriteprop, self.location)
-                       self.mwritepropdef = mwritepropdef
-                       modelbuilder.mpropdef2npropdef[mwritepropdef] = self
-               end
-       end
-
-       redef fun build_signature(modelbuilder, nclassdef)
+redef class ModelBuilder
+       # Run phases on all loaded modules
+       fun run_phases
        do
-               var mpropdef = self.mpropdef
-               if mpropdef == null then return # Error thus skiped
-               var mmodule = mpropdef.mclassdef.mmodule
-               var mtype: nullable MType = null
-
-               var ntype = self.n_type
-               if ntype != null then
-                       mtype = modelbuilder.resolve_mtype(nclassdef, ntype)
-                       if mtype == null then return
-               end
-
-               if mtype == null then
-                       var nexpr = self.n_expr
-                       if nexpr != null then
-                               if nexpr isa ANewExpr then
-                                       mtype = modelbuilder.resolve_mtype(nclassdef, nexpr.n_type)
-                               else if nexpr isa AIntExpr then
-                                       var cla = modelbuilder.try_get_mclass_by_name(nexpr, mmodule, "Int")
-                                       if cla != null then mtype = cla.mclass_type
-                               else if nexpr isa AFloatExpr then
-                                       var cla = modelbuilder.try_get_mclass_by_name(nexpr, mmodule, "Float")
-                                       if cla != null then mtype = cla.mclass_type
-                               else if nexpr isa ACharExpr then
-                                       var cla = modelbuilder.try_get_mclass_by_name(nexpr, mmodule, "Char")
-                                       if cla != null then mtype = cla.mclass_type
-                               else if nexpr isa ABoolExpr then
-                                       var cla = modelbuilder.try_get_mclass_by_name(nexpr, mmodule, "Bool")
-                                       if cla != null then mtype = cla.mclass_type
-                               else if nexpr isa ASuperstringExpr then
-                                       var cla = modelbuilder.try_get_mclass_by_name(nexpr, mmodule, "String")
-                                       if cla != null then mtype = cla.mclass_type
-                               else if nexpr isa AStringFormExpr then
-                                       var cla = modelbuilder.try_get_mclass_by_name(nexpr, mmodule, "String")
-                                       if cla != null then mtype = cla.mclass_type
-                               else
-                                       modelbuilder.error(self, "Error: Untyped attribute {mpropdef}. Implicit typing allowed only for literals and new.")
-                               end
-
-                       else
-                               modelbuilder.error(self, "Error: Untyped attribute {mpropdef}")
-                       end
+               var mmodules = parsed_modules.to_a
+               model.mmodule_importation_hierarchy.sort(mmodules)
+               var nmodules = new Array[AModule]
+               for mm in mmodules do
+                       if mm.is_fictive then continue
+                       nmodules.add(mmodule2node(mm).as(not null))
                end
+               toolcontext.run_phases(nmodules)
 
-               if mtype == null then return
-
-               mpropdef.static_mtype = mtype
-
-               var mreadpropdef = self.mreadpropdef
-               if mreadpropdef != null then
-                       var msignature = new MSignature(new Array[MParameter], mtype)
-                       mreadpropdef.msignature = msignature
-               end
-
-               var msritepropdef = self.mwritepropdef
-               if mwritepropdef != null then
-                       var name: String
-                       if n_id != null then
-                               name = n_id.text.substring_from(1)
-                       else
-                               name = n_id2.text
-                       end
-                       var mparameter = new MParameter(name, mtype, false)
-                       var msignature = new MSignature([mparameter], null)
-                       mwritepropdef.msignature = msignature
+               if toolcontext.opt_only_metamodel.value then
+                       self.toolcontext.info("*** ONLY METAMODEL", 1)
+                       toolcontext.quit
                end
        end
 
-       redef fun check_signature(modelbuilder, nclassdef)
-       do
-               var mpropdef = self.mpropdef
-               if mpropdef == null then return # Error thus skiped
-               var mmodule = mpropdef.mclassdef.mmodule
-               var ntype = self.n_type
-               var mtype = self.mpropdef.static_mtype
-               if mtype == null then return # Error thus skiped
-
-               # Lookup for signature in the precursor
-               # FIXME all precursors should be considered
-               if not mpropdef.is_intro then
-                       var precursor_type = mpropdef.mproperty.intro.static_mtype
-                       if precursor_type == null then return
-
-                       if mtype != precursor_type then
-                               modelbuilder.error(ntype.as(not null), "Redef Error: Wrong static type. found {mtype}, expected {precursor_type}.")
-                               return
-                       end
-               end
-
-               # Check getter and setter
-               var meth = self.mreadpropdef
-               if meth != null then self.check_method_signature(modelbuilder, nclassdef, meth)
-               meth = self.mwritepropdef
-               if meth != null then self.check_method_signature(modelbuilder, nclassdef, meth)
-       end
-
-       private fun check_method_signature(modelbuilder: ModelBuilder, nclassdef: AClassdef, mpropdef: MMethodDef)
-       do
-               var mmodule = mpropdef.mclassdef.mmodule
-               var nsig = self.n_type
-               var mysignature = mpropdef.msignature
-               if mysignature == null then return # Error thus skiped
-
-               # Lookup for signature in the precursor
-               # FIXME all precursors should be considered
-               if not mpropdef.is_intro then
-                       var msignature = mpropdef.mproperty.intro.msignature
-                       if msignature == null then return
-
-                       if mysignature.arity != msignature.arity then
-                               var node: ANode
-                               if nsig != null then node = nsig else node = self
-                               modelbuilder.error(node, "Redef Error: {mysignature.arity} parameters found, {msignature.arity} expected. Signature is {mpropdef}{msignature}")
-                               return
-                       end
-                       var precursor_ret_type = msignature.return_mtype
-                       var ret_type = mysignature.return_mtype
-                       if ret_type != null and precursor_ret_type == null then
-                               var node: ANode
-                               if nsig != null then node = nsig else node = self
-                               modelbuilder.error(node, "Redef Error: {mpropdef.mproperty} is a procedure, not a function.")
-                               return
-                       end
-
-                       if mysignature.arity > 0 then
-                               # Check parameters types
-                               for i in [0..mysignature.arity[ do
-                                       var myt = mysignature.mparameters[i].mtype
-                                       var prt = msignature.mparameters[i].mtype
-                                       if not myt.is_subtype(mmodule, nclassdef.mclassdef.bound_mtype, prt) and
-                                                       not prt.is_subtype(mmodule, nclassdef.mclassdef.bound_mtype, myt) then
-                                               var node: ANode
-                                               if nsig != null then node = nsig else node = self
-                                               modelbuilder.error(node, "Redef Error: Wrong type for parameter `{mysignature.mparameters[i].name}'. found {myt}, expected {prt}.")
-                                       end
-                               end
-                       end
-                       if precursor_ret_type != null then
-                               if ret_type == null then
-                                       # Inherit the return type
-                                       ret_type = precursor_ret_type
-                               else if not ret_type.is_subtype(mmodule, nclassdef.mclassdef.bound_mtype, precursor_ret_type) then
-                                       var node: ANode
-                                       if nsig != null then node = nsig else node = self
-                                       modelbuilder.error(node, "Redef Error: Wrong return type. found {ret_type}, expected {precursor_ret_type}.")
-                               end
-                       end
-               end
-       end
-end
-
-redef class ATypePropdef
-       # The associated MVirtualTypeDef once build by a `ModelBuilder'
-       var mpropdef: nullable MVirtualTypeDef
-       redef fun build_property(modelbuilder, nclassdef)
-       do
-               var mclassdef = nclassdef.mclassdef.as(not null)
-               var name = self.n_id.text
-               var mprop = modelbuilder.try_get_mproperty_by_name(self.n_id, mclassdef, name)
-               if mprop == null then
-                       var mvisibility = new_property_visibility(modelbuilder, nclassdef, self.n_visibility)
-                       mprop = new MVirtualTypeProp(mclassdef, name, mvisibility)
-                       if not self.check_redef_keyword(modelbuilder, nclassdef, self.n_kwredef, false, mprop) then return
-               else
-                       if not self.check_redef_keyword(modelbuilder, nclassdef, self.n_kwredef, true, mprop) then return
-                       assert mprop isa MVirtualTypeProp
-                       check_redef_property_visibility(modelbuilder, nclassdef, self.n_visibility, mprop)
-               end
-               nclassdef.mprop2npropdef[mprop] = self
-
-               var mpropdef = new MVirtualTypeDef(mclassdef, mprop, self.location)
-               self.mpropdef = mpropdef
-       end
-
-       redef fun build_signature(modelbuilder, nclassdef)
-       do
-               var mpropdef = self.mpropdef
-               if mpropdef == null then return # Error thus skiped
-               var mmodule = mpropdef.mclassdef.mmodule
-               var mtype: nullable MType = null
-
-               var ntype = self.n_type
-               mtype = modelbuilder.resolve_mtype(nclassdef, ntype)
-               if mtype == null then return
-
-               mpropdef.bound = mtype
-               # print "{mpropdef}: {mtype}"
-       end
-
-       redef fun check_signature(modelbuilder, nclassdef)
-       do
-               var bound = self.mpropdef.bound
-
-               # Fast case: the bound is not a formal type
-               if not bound isa MVirtualType then return
-
-               var mmodule = nclassdef.mclassdef.mmodule
-               var anchor = nclassdef.mclassdef.bound_mtype
-
-               # Slow case: progress on each resolution until: (i) we loop, or (ii) we found a non formal type
-               var seen = [self.mpropdef.mproperty.mvirtualtype]
-               loop
-                       if seen.has(bound) then
-                               seen.add(bound)
-                               modelbuilder.error(self, "Error: circularity of virtual type definition: {seen.join(" -> ")}")
-                               return
-                       end
-                       seen.add(bound)
-                       var next = bound.lookup_bound(mmodule, anchor)
-                       if not next isa MVirtualType then return
-                       bound = next
-               end
+       # Load module `filename` and add it as a conditional importation of `mmodule`.
+       #
+       # This means that current (and future) submodules of `module` will also import `filename`.
+       fun inject_module_subimportation(mmodule: MModule, filename: String)
+       do
+               var am = load_module(filename)
+               if am == null then return # forward error
+               var mm = am.mmodule
+               if mm == null then return # forward error
+               # Add the new module before the existing submodules in the hierarchy
+               for subm in mmodule.in_importation.direct_smallers do
+                       subm.set_imported_mmodules([mm])
+               end
+               # Register the new module as a conditional_importations for future submodules
+               conditional_importations.add([mm, mmodule])
+               # Register the new amodule to be processed by `run_phases`
+               toolcontext.todo_nmodules.unshift am
        end
 end