X-Git-Url: http://nitlanguage.org

diff --git a/src/modelbuilder.nit b/src/modelbuilder.nit
index af60c66..eac98df 100644
--- a/src/modelbuilder.nit
+++ b/src/modelbuilder.nit
@@ -22,11 +22,7 @@
 # FIXME add missing error checks
 module modelbuilder
 
-import parser
 import model
-import poset
-import opts
-import toolcontext
 import phase
 
 private import more_collections
@@ -35,25 +31,64 @@ 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")
+	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")
+	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")
+	var opt_only_parse: OptionBool = new OptionBool("Only proceed to parse step of loaders", "--only-parse")
+
+	# Option --ignore-visibility
+	var opt_ignore_visibility: OptionBool = 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)
+		option_context.add_option(opt_path, opt_only_parse, opt_only_metamodel, opt_ignore_visibility)
 	end
 
 	fun modelbuilder: ModelBuilder do return modelbuilder_real.as(not null)
 	private var modelbuilder_real: nullable ModelBuilder = null
 
+	# Run `process_mainmodule` on all phases
+	fun run_global_phases(mmodules: Array[MModule])
+	do
+		assert not mmodules.is_empty
+		var mainmodule
+		if mmodules.length == 1 then
+			mainmodule = mmodules.first
+		else
+			# We need a main module, so we build it by importing all modules
+			mainmodule = new MModule(modelbuilder.model, null, mmodules.first.name, new Location(mmodules.first.location.file, 0, 0, 0, 0))
+			mainmodule.is_fictive = true
+			mainmodule.set_imported_mmodules(mmodules)
+		end
+		for phase in phases_list do
+			if phase.disabled then continue
+			phase.process_mainmodule(mainmodule, mmodules)
+		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
 
+
 # A model builder knows how to load nit source files and build the associated model
 class ModelBuilder
 	# The model where new modules, classes and properties are added
@@ -96,18 +131,15 @@ class ModelBuilder
 			paths.append(path_env.split_with(':'))
 		end
 
-		path_env = "NIT_DIR".environ
-		if not path_env.is_empty then
-			var libname = "{path_env}/lib"
+		var nit_dir = toolcontext.nit_dir
+		if nit_dir != null then
+			var libname = "{nit_dir}/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 a bunch of modules.
-	# `modules' can contains filenames or module names.
+	# `modules` can contains filenames or module names.
 	# Imported modules are automatically loaded and modelized.
 	# The result is the corresponding model elements.
 	# Errors and warnings are printed with the toolcontext.
@@ -118,9 +150,9 @@ class ModelBuilder
 		var time0 = get_time
 		# Parse and recursively load
 		self.toolcontext.info("*** PARSE ***", 1)
-		var mmodules = new Array[MModule]
+		var mmodules = new ArraySet[MModule]
 		for a in modules do
-			var nmodule = self.load_module(null, a)
+			var nmodule = self.load_module(a)
 			if nmodule == null then continue # Skip error
 			mmodules.add(nmodule.mmodule.as(not null))
 		end
@@ -134,13 +166,13 @@ class ModelBuilder
 			exit(0)
 		end
 
-		return mmodules
+		return mmodules.to_a
 	end
 
-	# Return a class named `name' visible by the module `mmodule'.
+	# 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.
+	# 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
@@ -163,11 +195,11 @@ class ModelBuilder
 		return res
 	end
 
-	# Return a property named `name' on the type `mtype' visible in the module `mmodule'.
+	# 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.
+	# 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
@@ -186,28 +218,55 @@ class ModelBuilder
 			if not mmodule.is_visible(mprop.intro_mclassdef.mmodule, mprop.visibility) then continue
 			if res == null then
 				res = mprop
-			else
+				continue
+			end
+
+			# Two global properties?
+			# First, special case for init, keep the most specific ones
+			if res isa MMethod and mprop isa MMethod and res.is_init and mprop.is_init then
 				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
+				if mproptype.is_subtype(mmodule, null, restype) then
+					# found a most specific constructor, so keep it
 					res = mprop
-				else
-					if ress == null then ress = new Array[MProperty]
-					ress.add(mprop)
+					continue
 				end
 			end
+
+			# Ok, just keep all prop in the ress table
+			if ress == null then
+				ress = new Array[MProperty]
+				ress.add(res)
+			end
+			ress.add(mprop)
 		end
-		if ress != null then
+
+		# There is conflict?
+		if ress != null and res isa MMethod and res.is_init then
+			# special case forinit again
 			var restype = res.intro_mclassdef.bound_mtype
+			var ress2 = new Array[MProperty]
 			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
+					ress2.add(mprop)
+				else if not mprop isa MMethod or not mprop.is_init then
+					ress2.add(mprop)
 				end
 			end
+			if ress2.is_empty then
+				ress = null
+			else
+				ress = ress2
+				ress.add(res)
+			end
+		end
+
+		if ress != null then
+			assert ress.length > 1
+			var s = new Array[String]
+			for mprop in ress do s.add mprop.full_name
+			self.error(anode, "Ambigous property name '{name}' for {mtype}; conflict between {s.join(" and ")}")
 		end
 
 		self.try_get_mproperty_by_name2_cache[mmodule, mtype, name] = res
@@ -227,96 +286,98 @@ class ModelBuilder
 	# 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
+	#   * `toolcontext.nit_dir`
 	# 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
+	# Like (an used by) `get_mmodule_by_name` but just return the ModulePath
+	private fun search_mmodule_by_name(anode: ANode, mgroup: nullable MGroup, name: String): nullable ModulePath
 	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
+		# First, look in groups
+		var c = mgroup
+		while c != null do
+			var dirname = c.filepath
+			if dirname == null then break # virtual group
+			if dirname.has_suffix(".nit") then break # singleton project
 
 			# 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)
+				var res = self.identify_file(try_file.simplify_path)
+				assert res != null
+				return res
 			end
 
-			# Third, try if the requested module is itself an owner
+			# Third, try if the requested module is itself a group
 			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)
+				var res = self.identify_file(try_file.simplify_path)
+				assert res != null
+				return res
 			end
 
-			lastmodule = mmodule
-			mmodule = mmodule.direct_owner
+			c = c.parent
 		end
 
-		if modules != null then
-			for candidate in modules do
-				if candidate.direct_owner == null then
-					return candidate
+		# Look at some known directories
+		var lookpaths = self.paths
+
+		# Look in the directory of the group project also (even if not explicitely in the path)
+		if mgroup != null then
+			# path of the root group
+			var dirname = mgroup.mproject.root.filepath
+			if dirname != null then
+				dirname = dirname.join_path("..").simplify_path
+				if not lookpaths.has(dirname) and dirname.file_exists then
+					lookpaths = lookpaths.to_a
+					lookpaths.add(dirname)
 				end
 			end
 		end
 
-		# Look at some known directories
-		var lookpaths = self.paths
+		var candidate = search_module_in_paths(anode.hot_location, name, lookpaths)
 
-		# 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)
+		if candidate == null then
+			if mgroup != null then
+				error(anode, "Error: cannot find module {name} from {mgroup.name}. tried {lookpaths.join(", ")}")
+			else
+				error(anode, "Error: cannot find module {name}. tried {lookpaths.join(", ")}")
 			end
+			return null
 		end
+		return candidate
+	end
+
+	# Get a module by its short name; if required, the module is loaded, parsed and its hierarchies computed.
+	# If `mgroup` is set, then the module search starts from it up to the top level (see `paths`);
+	# if `mgroup` 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.
+	fun get_mmodule_by_name(anode: ANode, mgroup: nullable MGroup, name: String): nullable MModule
+	do
+		var path = search_mmodule_by_name(anode, mgroup, name)
+		if path == null then return null # Forward error
+		var res = self.load_module(path.filepath)
+		if res == null then return null # Forward error
+		return res.mmodule.as(not null)
+	end
 
+	# Search a module `name` from path `lookpaths`.
+	# If found, the path of the file is returned
+	private fun search_module_in_paths(location: nullable Location, name: String, lookpaths: Collection[String]): nullable ModulePath
+	do
 		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}")
+					# try to disambiguate conflicting modules
+					var abs_candidate = module_absolute_path(candidate)
+					var abs_try_file = module_absolute_path(try_file)
+					if abs_candidate != abs_try_file then
+						toolcontext.error(location, "Error: conflicting module file for {name}: {candidate} {try_file}")
+					end
 				end
 			end
 			try_file = (dirname + "/" + name + "/" + name + ".nit").simplify_path
@@ -324,35 +385,153 @@ class ModelBuilder
 				if candidate == null then
 					candidate = try_file
 				else if candidate != try_file then
-					error(anode, "Error: conflicting module file for {name}: {candidate} {try_file}")
+					# try to disambiguate conflicting modules
+					var abs_candidate = module_absolute_path(candidate)
+					var abs_try_file = module_absolute_path(try_file)
+					if abs_candidate != abs_try_file then
+						toolcontext.error(location, "Error: conflicting module file for {name}: {candidate} {try_file}")
+					end
 				end
 			end
 		end
-		if candidate == null then
-			if origmmodule != null then
-				error(anode, "Error: cannot find module {name} from {origmmodule}. tried {tries.join(", ")}")
+		if candidate == null then return null
+		return identify_file(candidate)
+	end
+
+	# cache for `identify_file` by realpath
+	private var identified_files = new HashMap[String, nullable ModulePath]
+
+	# Identify a source file
+	# Load the associated project and groups if required
+	private fun identify_file(path: String): nullable ModulePath
+	do
+		# special case for not a nit file
+		if path.file_extension != "nit" then
+			# search in known -I paths
+			var res = search_module_in_paths(null, path, self.paths)
+			if res != null then return res
+
+			# Found nothins? maybe it is a group...
+			var candidate = null
+			if path.file_exists then
+				var mgroup = get_mgroup(path)
+				if mgroup != null then
+					var owner_path = mgroup.filepath.join_path(mgroup.name + ".nit")
+					if owner_path.file_exists then candidate = owner_path
+				end
+			end
+
+			if candidate == null then
+				toolcontext.error(null, "Error: cannot find module `{path}`.")
+				return null
+			end
+			path = candidate
+		end
+
+		# Fast track, the path is already known
+		var pn = path.basename(".nit")
+		var rp = module_absolute_path(path)
+		if identified_files.has_key(rp) then return identified_files[rp]
+
+		# Search for a group
+		var mgrouppath = path.join_path("..").simplify_path
+		var mgroup = get_mgroup(mgrouppath)
+
+		if mgroup == null then
+			# singleton project
+			var mproject = new MProject(pn, model)
+			mgroup = new MGroup(pn, mproject, null) # same name for the root group
+			mgroup.filepath = path
+			mproject.root = mgroup
+			toolcontext.info("found project `{pn}` at {path}", 2)
+		end
+
+		var res = new ModulePath(pn, path, mgroup)
+		mgroup.module_paths.add(res)
+
+		identified_files[rp] = res
+		return res
+	end
+
+	# groups by path
+	private var mgroups = new HashMap[String, nullable MGroup]
+
+	# return the mgroup associated to a directory path
+	# if the directory is not a group null is returned
+	private fun get_mgroup(dirpath: String): nullable MGroup
+	do
+		var rdp = module_absolute_path(dirpath)
+		if mgroups.has_key(rdp) then
+			return mgroups[rdp]
+		end
+
+		# Hack, a group is determined by:
+		# * the presence of a honomymous nit file
+		# * the fact that the directory is named `src`
+		var pn = rdp.basename(".nit")
+		var mp = dirpath.join_path(pn + ".nit").simplify_path
+
+		var dirpath2 = dirpath
+		if not mp.file_exists then
+			if pn == "src" then
+				# With a src directory, the group name is the name of the parent directory
+				dirpath2 = rdp.dirname
+				pn = dirpath2.basename("")
 			else
-				error(anode, "Error: cannot find module {name}. tried {tries.join(", ")}")
+				return null
 			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)
+
+		# check parent directory
+		var parentpath = dirpath.join_path("..").simplify_path
+		var parent = get_mgroup(parentpath)
+
+		var mgroup
+		if parent == null then
+			# no parent, thus new project
+			var mproject = new MProject(pn, model)
+			mgroup = new MGroup(pn, mproject, null) # same name for the root group
+			mproject.root = mgroup
+			toolcontext.info("found project `{mproject}` at {dirpath}", 2)
+		else
+			mgroup = new MGroup(pn, parent.mproject, parent)
+			toolcontext.info("found sub group `{mgroup.full_name}` at {dirpath}", 2)
+		end
+		var readme = dirpath2.join_path("README.md")
+		if not readme.file_exists then readme = dirpath2.join_path("README")
+		if readme.file_exists then
+			var mdoc = new MDoc
+			var s = new IFStream.open(readme)
+			while not s.eof do
+				mdoc.content.add(s.read_line)
+			end
+			mgroup.mdoc = mdoc
+			mdoc.original_mentity = mgroup
+		end
+		mgroup.filepath = dirpath
+		mgroups[rdp] = mgroup
+		return mgroup
 	end
 
-	# Try to load a module using a path.
+	# Transform relative paths (starting with '../') into absolute paths
+	private fun module_absolute_path(path: String): String do
+		return getcwd.join_path(path).simplify_path
+	end
+
+	# Try to load a module AST 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
+	fun load_module_ast(filename: String): nullable AModule
 	do
+		if filename.file_extension != "nit" then
+			self.toolcontext.error(null, "Error: file {filename} is not a valid nit module.")
+			return null
+		end
 		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)
+		self.toolcontext.info("load module {filename}", 2)
 
 		# Load the file
 		var file = new IFStream.open(filename)
@@ -360,6 +539,7 @@ class ModelBuilder
 		var parser = new Parser(lexer)
 		var tree = parser.parse
 		file.close
+		var mod_name = filename.basename(".nit")
 
 		# Handle lexer and parser error
 		var nmodule = tree.n_base
@@ -370,8 +550,64 @@ class ModelBuilder
 			return null
 		end
 
+		return nmodule
+	end
+
+	# Try to load a module and its imported modules using a path.
+	# Display an error if there is a problem (IO / lexer / parser / importation) and return null
+	# Note: usually, you do not need this method, use `get_mmodule_by_name` instead.
+	fun load_module(filename: String): nullable AModule
+	do
+		# Look for the module
+		var file = identify_file(filename)
+		if file == null then return null # forward error
+
+		# Already known and loaded? then return it
+		var mmodule = file.mmodule
+		if mmodule != null then
+			return mmodule2nmodule[mmodule]
+		end
+
+		# Load it manually
+		var nmodule = load_module_ast(file.filepath)
+		if nmodule == null then return null # forward error
+
+		# build the mmodule and load imported modules
+		mmodule = build_a_mmodule(file.mgroup, file.name, nmodule)
+
+		if mmodule == null then return null # forward error
+
+		# Update the file information
+		file.mmodule = mmodule
+
+		# Load imported module
+		build_module_importation(nmodule)
+
+		return nmodule
+	end
+
+	fun load_rt_module(parent: MModule, nmodule: AModule, mod_name: String): nullable AModule
+	do
+		# Create the module
+		var mmodule = new MModule(model, parent.mgroup, mod_name, nmodule.location)
+		nmodule.mmodule = mmodule
+		nmodules.add(nmodule)
+		self.mmodule2nmodule[mmodule] = nmodule
+
+		var imported_modules = new Array[MModule]
+
+		imported_modules.add(parent)
+		mmodule.set_visibility_for(parent, intrude_visibility)
+
+		mmodule.set_imported_mmodules(imported_modules)
+
+		return nmodule
+	end
+
+	# Visit the AST and create the `MModule` object
+	private fun build_a_mmodule(mgroup: nullable MGroup, mod_name: String, nmodule: AModule): nullable MModule
+	do
 		# 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
@@ -383,14 +619,21 @@ class ModelBuilder
 		end
 
 		# Create the module
-		var mmodule = new MModule(model, owner, mod_name, nmodule.location)
+		var mmodule = new MModule(model, mgroup, mod_name, nmodule.location)
 		nmodule.mmodule = mmodule
 		nmodules.add(nmodule)
 		self.mmodule2nmodule[mmodule] = nmodule
 
-		build_module_importation(nmodule)
+		if decl != null then
+			var ndoc = decl.n_doc
+			if ndoc != null then
+				var mdoc = ndoc.to_mdoc
+				mmodule.mdoc = mdoc
+				mdoc.original_mentity = mmodule
+			end
+		end
 
-		return nmodule
+		return mmodule
 	end
 
 	# Analysis the module importation and fill the module_importation_hierarchy
@@ -406,15 +649,30 @@ class ModelBuilder
 			if not aimport isa AStdImport then
 				continue
 			end
+			var mgroup = mmodule.mgroup
+			if aimport.n_name.n_quad != null then mgroup = null # Start from top level
+			for grp in aimport.n_name.n_path do
+				var path = search_mmodule_by_name(grp, mgroup, grp.text)
+				if path == null then return # Skip error
+				mgroup = path.mgroup
+			end
 			var mod_name = aimport.n_name.n_id.text
-			var sup = self.get_mmodule_by_name(aimport.n_name, mmodule, mod_name)
+			var sup = self.get_mmodule_by_name(aimport.n_name, mgroup, mod_name)
 			if sup == null then continue # Skip error
+			aimport.mmodule = sup
 			imported_modules.add(sup)
 			var mvisibility = aimport.n_visibility.mvisibility
 			if mvisibility == protected_visibility then
 				error(aimport.n_visibility, "Error: only properties can be protected.")
 				return
 			end
+			if sup == mmodule then
+				error(aimport.n_name, "Error: Dependency loop in module {mmodule}.")
+			end
+			if sup.in_importation < mmodule then
+				error(aimport.n_name, "Error: Dependency loop between modules {mmodule} and {sup}.")
+				return
+			end
 			mmodule.set_visibility_for(sup, mvisibility)
 		end
 		if stdimport then
@@ -427,31 +685,43 @@ class ModelBuilder
 		end
 		self.toolcontext.info("{mmodule} imports {imported_modules.join(", ")}", 3)
 		mmodule.set_imported_mmodules(imported_modules)
+
+		# TODO: Correctly check for useless importation
+		# It is even doable?
+		var directs = mmodule.in_importation.direct_greaters
+		for nim in nmodule.n_imports do
+			if not nim isa AStdImport then continue
+			var im = nim.mmodule
+			if im == null then continue
+			if directs.has(im) then continue
+			# This generates so much noise that it is simpler to just comment it
+			#warning(nim, "Warning: possible useless importation of {im}")
+		end
 	end
 
 	# All the loaded modules
 	var nmodules: Array[AModule] = new Array[AModule]
 
 	# Register the nmodule associated to each mmodule
-	# FIXME: why not refine the MModule class with a nullable attribute?
+	# FIXME: why not refine the `MModule` class with a nullable attribute?
 	var mmodule2nmodule: HashMap[MModule, AModule] = new HashMap[MModule, AModule]
 
 	# Helper function to display an error on a node.
-	# Alias for `self.toolcontext.error(n.hot_location, text)'
+	# 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)'
+	# 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
+	# 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: MClass, mmodule: MModule): MMethod
 	do
 		var res = mmodule.try_get_primitive_method(name, recv)
 		if res == null then
@@ -462,8 +732,36 @@ class ModelBuilder
 	end
 end
 
+# placeholder to a module file identified but not always loaded in a project
+private class ModulePath
+	# The name of the module
+	# (it's the basename of the filepath)
+	var name: String
+
+	# The human path of the module
+	var filepath: String
+
+	# The group (and the project) of the possible module
+	var mgroup: MGroup
+
+	# The loaded module (if any)
+	var mmodule: nullable MModule = null
+
+	redef fun to_s do return filepath
+end
+
+redef class MGroup
+	# modules paths associated with the group
+	private var module_paths = new Array[ModulePath]
+end
+
+redef class AStdImport
+	# The imported module once determined
+	var mmodule: nullable MModule = null
+end
+
 redef class AModule
-	# The associated MModule once build by a `ModelBuilder'
+	# 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
@@ -485,3 +783,30 @@ end
 redef class APrivateVisibility
 	redef fun mvisibility do return private_visibility
 end
+
+redef class ADoc
+	private var mdoc_cache: nullable MDoc
+	fun to_mdoc: MDoc
+	do
+		var res = mdoc_cache
+		if res != null then return res
+		res = new MDoc
+		for c in n_comment do
+			var text = c.text
+			if text.length < 2 then
+				res.content.add ""
+				continue
+			end
+			assert text.chars[0] == '#'
+			if text.chars[1] == ' ' then
+				text = text.substring_from(2) # eat starting `#` and space
+			else
+				text = text.substring_from(1) # eat atarting `#` only
+			end
+			if text.chars.last == '\n' then text = text.substring(0, text.length-1) # drop \n
+			res.content.add(text)
+		end
+		mdoc_cache = res
+		return res
+	end
+end