sema: Add missing type-checking logic on attributes with bodies

src/semantize/typing.nit

@@ -629,6 +629,21 @@ private class TypeVisitor
 	# Some loops had been visited during the visit
 	var has_loop = false
 
+	# Visit `nbody`, the body of `npropdef`
+	fun visit_body(npropdef: APropdef, nbody: nullable AExpr)
+	do
+		if nbody != null then
+			loop
+				dirty = false
+				visit_stmt(nbody)
+				if not has_loop or not dirty then break
+			end
+		end
+
+		var post_visitor = new PostTypingVisitor(self)
+		post_visitor.enter_visit(npropdef)
+	end
+
 	fun set_variable(node: AExpr, variable: Variable, mtype: nullable MType)
 	do
 		var flow = node.after_flow_context
@@ -1014,14 +1029,7 @@ redef class AMethPropdef
 		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)
+		v.visit_body(self, nblock)
 
 		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
@@ -1069,12 +1077,11 @@ redef class AAttrPropdef
 			v.visit_expr_subtype(nexpr, mtype)
 		end
 		var nblock = self.n_block
-		if nblock != null then
-			v.visit_stmt(nblock)
-			if not nblock.after_flow_context.is_unreachable then
-				# We reach the end of the init without having a return, it is bad
-				v.error(self, "Error: reached end of block; expected `return`.")
-			end
+		v.visit_body(self, nblock)
+
+		if nblock != null and not nblock.after_flow_context.is_unreachable then
+			# We reach the end of the init without having a return, it is bad
+			v.error(self, "Error: reached end of block; expected `return`.")
 		end
 	end
 end
@@ -1132,18 +1139,6 @@ redef class AExpr
 		end
 		return res
 	end
-
-	# Type the expression as if located in `visited_mpropdef`
-	# `TypeVisitor` and `PostTypingVisitor` will be used to do the typing, see them for more information.
-	#
-	# `visited_mpropdef`: Correspond to the evaluation context in which the expression is located.
-	fun do_typing(modelbuilder: ModelBuilder, visited_mpropdef: MPropDef)
-	do
-		var type_visitor = new TypeVisitor(modelbuilder, visited_mpropdef)
-		type_visitor.visit_stmt(self)
-		var post_visitor = new PostTypingVisitor(type_visitor)
-		post_visitor.enter_visit(self)
-	end
 end
 
 redef class ABlockExpr

tests/base_adaptive_loop_attr.nit

@@ -0,0 +1,45 @@
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import core::kernel
+class A
+	fun m: nullable Object do
+		var b = null
+		loop
+			if b != null then return b
+			b = 1
+		end
+	end
+
+	var x: nullable Object do
+		var b = null
+		loop
+			if b != null then return b
+			b = 2
+		end
+	end
+
+	var y: nullable Object is lazy do
+		var b = null
+		loop
+			if b != null then return b
+			b = 3
+		end
+	end
+end
+
+var a = new A
+a.m.as(not null).output
+a.x.as(not null).output
+a.y.as(not null).output

tests/base_attr_useless_check.nit

@@ -0,0 +1,43 @@
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import core::kernel
+
+class A
+	fun m: Int do
+		var i = 1
+		if i == null then return 0
+		return i.as(Int)
+	end
+
+	var x: Int do
+		var i = 2
+		if i == null then return 0
+		return i.as(Int)
+	end
+
+	var y: Int is lazy do
+		var i = 3
+		if i isa Int then return i
+		return 0
+	end
+
+	var z: Int = 4.as(Int)
+end
+
+var a = new A
+a.m.output
+a.x.output
+a.y.output
+a.z.output

tests/sav/base_adaptive_loop_attr.res

@@ -0,0 +1,3 @@
+1
+2
+3

tests/sav/base_attr_useless_check.res

@@ -0,0 +1,10 @@
+base_attr_useless_check.nit:20,6: Warning: expression is not null, since it is a `Int`.
+base_attr_useless_check.nit:21,10--18: Warning: expression is already a `Int`.
+base_attr_useless_check.nit:26,6: Warning: expression is not null, since it is a `Int`.
+base_attr_useless_check.nit:27,10--18: Warning: expression is already a `Int`.
+base_attr_useless_check.nit:32,6--14: Warning: expression is already a `Int`.
+base_attr_useless_check.nit:36,15--23: Warning: expression is already a `Int`.
+1
+2
+3
+4