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

diff --git a/src/semantize/typing.nit b/src/semantize/typing.nit
index ada6160..1b53f65 100644
--- a/src/semantize/typing.nit
+++ b/src/semantize/typing.nit
@@ -20,6 +20,7 @@ module typing
 
 import modelize
 import local_var_init
+import literal
 
 redef class ToolContext
 	var typing_phase: Phase = new TypingPhase(self, [flow_phase, modelize_property_phase, local_var_init_phase])
@@ -184,12 +185,12 @@ private class TypeVisitor
 	end
 
 
-	fun visit_expr_cast(node: ANode, nexpr: AExpr, ntype: AType): nullable MType
+	fun check_expr_cast(node: ANode, nexpr: AExpr, ntype: AType): nullable MType
 	do
-		var sub = visit_expr(nexpr)
+		var sub = nexpr.mtype
 		if sub == null then return null # Forward error
 
-		var sup = self.resolve_mtype(ntype)
+		var sup = ntype.mtype
 		if sup == null then return null # Forward error
 
 		if sup == sub then
@@ -217,6 +218,10 @@ private class TypeVisitor
 	# Else return true.
 	fun check_can_be_null(anode: ANode, mtype: MType): Bool
 	do
+		if mtype isa MNullType then
+			modelbuilder.warning(anode, "useless-null-test", "Warning: expression is always `null`.")
+			return true
+		end
 		if can_be_null(mtype) then return true
 
 		if mtype isa MFormalType then
@@ -240,7 +245,7 @@ private class TypeVisitor
 		if not mtype2 isa MNullType then return
 
 		# Check of useless null
-		if not check_can_be_null(anode.n_expr, mtype) then return
+		if not can_be_null(mtype) then return
 
 		if mtype isa MNullType then
 			# Because of type adaptation, we cannot just stop here
@@ -329,6 +334,8 @@ private class TypeVisitor
 		if recvtype isa MNullType and not mproperty.is_null_safe then
 			self.error(node, "Error: method `{name}` called on `null`.")
 			return null
+		else if unsafe_type isa MNullableType and not mproperty.is_null_safe then
+			modelbuilder.advice(node, "call-on-nullable", "Warning: method call on a nullable receiver `{recvtype}`.")
 		end
 
 		if is_toplevel_context and recv_is_self and not mproperty.is_toplevel then
@@ -646,7 +653,7 @@ end
 
 redef class Variable
 	# The declared type of the variable
-	var declared_type: nullable MType
+	var declared_type: nullable MType is writable
 
 	# Was the variable type-adapted?
 	# This is used to speedup type retrieval while it remains `false`
@@ -716,9 +723,6 @@ end
 redef class AMethPropdef
 	redef fun do_typing(modelbuilder: ModelBuilder)
 	do
-		var nblock = self.n_block
-		if nblock == null then return
-
 		var mpropdef = self.mpropdef
 		if mpropdef == null then return # skip error
 
@@ -740,12 +744,18 @@ redef class AMethPropdef
 			variable.declared_type = mtype
 		end
 
+		var nblock = self.n_block
+		if nblock == null then return
+
 		loop
 			v.dirty = false
 			v.visit_stmt(nblock)
 			if not v.has_loop or not v.dirty then break
 		end
 
+		var post_visitor = new PostTypingVisitor(v)
+		post_visitor.enter_visit(self)
+
 		if not nblock.after_flow_context.is_unreachable and msignature.return_mtype != null then
 			# We reach the end of the function without having a return, it is bad
 			v.error(self, "Error: reached end of function; expected `return` with a value.")
@@ -753,20 +763,33 @@ redef class AMethPropdef
 	end
 end
 
+private class PostTypingVisitor
+	super Visitor
+	var type_visitor: TypeVisitor
+	redef fun visit(n) do
+		n.visit_all(self)
+		n.accept_post_typing(type_visitor)
+	end
+end
+
+redef class ANode
+	private fun accept_post_typing(v: TypeVisitor) do end
+end
+
 redef class AAttrPropdef
 	redef fun do_typing(modelbuilder: ModelBuilder)
 	do
 		if not has_value then return
 
-		var mpropdef = self.mpropdef
-		if mpropdef == null then return # skip error
+		var mpropdef = self.mreadpropdef
+		if mpropdef == null or mpropdef.msignature == null then return # skip error
 
 		var v = new TypeVisitor(modelbuilder, mpropdef.mclassdef.mmodule, mpropdef)
 		self.selfvariable = v.selfvariable
 
 		var nexpr = self.n_expr
 		if nexpr != null then
-			var mtype = self.mpropdef.static_mtype
+			var mtype = self.mtype
 			v.visit_expr_subtype(nexpr, mtype)
 		end
 		var nblock = self.n_block
@@ -958,7 +981,7 @@ redef class AVarReassignExpr
 
 		v.set_variable(self, variable, rettype)
 
-		self.is_typed = true
+		self.is_typed = rettype != null
 	end
 end
 
@@ -1004,9 +1027,11 @@ redef class AReturnExpr
 			else
 				v.visit_expr(nexpr)
 				v.error(nexpr, "Error: `return` with value in a procedure.")
+				return
 			end
 		else if ret_type != null then
 			v.error(self, "Error: `return` without value in a function.")
+			return
 		end
 		self.is_typed = true
 	end
@@ -1300,8 +1325,9 @@ redef class AOrElseExpr
 		end
 
 		if t1 isa MNullType then
-			v.error(n_expr, "Type Error: `or else` on `null`.")
-		else if v.check_can_be_null(n_expr, t1) then
+			self.mtype = t2
+			return
+		else if v.can_be_null(t1) then
 			t1 = t1.as_notnull
 		end
 
@@ -1317,6 +1343,16 @@ redef class AOrElseExpr
 		end
 		self.mtype = t
 	end
+
+	redef fun accept_post_typing(v)
+	do
+		var t1 = n_expr.mtype
+		if t1 == null then
+			return
+		else
+			v.check_can_be_null(n_expr, t1)
+		end
+	end
 end
 
 redef class ATrueExpr
@@ -1333,10 +1369,15 @@ redef class AFalseExpr
 	end
 end
 
-redef class AIntExpr
+redef class AIntegerExpr
 	redef fun accept_typing(v)
 	do
-		var mclass = v.get_mclass(self, "Int")
+		var mclass: nullable MClass = null
+		if value isa Byte then
+			mclass = v.get_mclass(self, "Byte")
+		else if value isa Int then
+			mclass = v.get_mclass(self, "Int")
+		end
 		if mclass == null then return # Forward error
 		self.mtype = mclass.mclass_type
 	end
@@ -1511,7 +1552,10 @@ redef class AIsaExpr
 	var cast_type: nullable MType
 	redef fun accept_typing(v)
 	do
-		var mtype = v.visit_expr_cast(self, self.n_expr, self.n_type)
+		v.visit_expr(n_expr)
+
+		var mtype = v.resolve_mtype(n_type)
+
 		self.cast_type = mtype
 
 		var variable = self.n_expr.its_variable
@@ -1525,12 +1569,24 @@ redef class AIsaExpr
 
 		self.mtype = v.type_bool(self)
 	end
+
+	redef fun accept_post_typing(v)
+	do
+		v.check_expr_cast(self, self.n_expr, self.n_type)
+	end
 end
 
 redef class AAsCastExpr
 	redef fun accept_typing(v)
 	do
-		self.mtype = v.visit_expr_cast(self, self.n_expr, self.n_type)
+		v.visit_expr(n_expr)
+
+		self.mtype = v.resolve_mtype(n_type)
+	end
+
+	redef fun accept_post_typing(v)
+	do
+		v.check_expr_cast(self, self.n_expr, self.n_type)
 	end
 end
 
@@ -1545,12 +1601,19 @@ redef class AAsNotnullExpr
 			return
 		end
 
-		if v.check_can_be_null(n_expr, mtype) then
+		if v.can_be_null(mtype) then
 			mtype = mtype.as_notnull
 		end
 
 		self.mtype = mtype
 	end
+
+	redef fun accept_post_typing(v)
+	do
+		var mtype = n_expr.mtype
+		if mtype == null then return
+		v.check_can_be_null(n_expr, mtype)
+	end
 end
 
 redef class AParExpr
@@ -1675,18 +1738,24 @@ redef class ABinopExpr
 	redef fun property_name do return operator
 	redef fun property_node do return n_op
 end
-redef class AEqExpr
+
+redef class AEqFormExpr
 	redef fun accept_typing(v)
 	do
 		super
 		v.null_test(self)
 	end
-end
-redef class ANeExpr
-	redef fun accept_typing(v)
+
+	redef fun accept_post_typing(v)
 	do
-		super
-		v.null_test(self)
+		var mtype = n_expr.mtype
+		var mtype2 = n_expr2.mtype
+
+		if mtype == null or mtype2 == null then return
+
+		if not mtype2 isa MNullType then return
+
+		v.check_can_be_null(n_expr, mtype)
 	end
 end
 
@@ -2050,7 +2119,7 @@ redef class AAttrAssignExpr
 		var mtype = self.attr_type
 
 		v.visit_expr_subtype(self.n_value, mtype)
-		self.is_typed = true
+		self.is_typed = mtype != null
 	end
 end
 
@@ -2061,9 +2130,9 @@ redef class AAttrReassignExpr
 		var mtype = self.attr_type
 		if mtype == null then return # Skip error
 
-		self.resolve_reassignment(v, mtype, mtype)
+		var rettype = self.resolve_reassignment(v, mtype, mtype)
 
-		self.is_typed = true
+		self.is_typed = rettype != null
 	end
 end