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

diff --git a/src/modelbuilder_base.nit b/src/modelbuilder_base.nit
index f01fbd8..4edd46d 100644
--- a/src/modelbuilder_base.nit
+++ b/src/modelbuilder_base.nit
@@ -74,13 +74,23 @@ class ModelBuilder
 			if res == null then
 				res = mclass
 			else
-				error(anode, "Ambigous class name '{name}'; conflict between {mclass.full_name} and {res.full_name}")
+				error(anode, "Error: ambiguous class name `{name}`; conflict between `{mclass.full_name}` and `{res.full_name}`.")
 				return null
 			end
 		end
 		return res
 	end
 
+	# Like `try_get_mclass_by_name` but display an error message when the class is not found
+	fun get_mclass_by_name(node: ANode, mmodule: MModule, name: String): nullable MClass
+	do
+		var mclass = try_get_mclass_by_name(node, mmodule, name)
+		if mclass == null then
+			error(node, "Type Error: missing primitive class `{name}'.")
+		end
+		return mclass
+	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).
@@ -158,7 +168,7 @@ class ModelBuilder
 			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 ")}")
+			self.error(anode, "Error: ambiguous property name `{name}` for `{mtype}`; conflict between {s.join(" and ")}.")
 		end
 
 		self.try_get_mproperty_by_name2_cache[mmodule, mtype, name] = res
@@ -176,10 +186,15 @@ class ModelBuilder
 
 	# Helper function to display an error on a node.
 	# Alias for `self.toolcontext.error(n.hot_location, text)`
+	#
+	# This automatically sets `n.is_broken` to true.
 	fun error(n: nullable ANode, text: String)
 	do
 		var l = null
-		if n != null then l = n.hot_location
+		if n != null then
+			l = n.hot_location
+			n.is_broken = true
+		end
 		self.toolcontext.error(l, text)
 	end
 
@@ -208,7 +223,7 @@ class ModelBuilder
 		if res == null then
 			var l = null
 			if n != null then l = n.hot_location
-			self.toolcontext.fatal_error(l, "Fatal Error: {recv} must have a property named {name}.")
+			self.toolcontext.fatal_error(l, "Fatal Error: `{recv}` must have a property named `{name}`.")
 			abort
 		end
 		return res
@@ -228,7 +243,7 @@ class ModelBuilder
 			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.")
+					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
@@ -243,7 +258,7 @@ class ModelBuilder
 				if p.name != name then continue
 
 				if not ntype.n_types.is_empty then
-					error(ntype, "Type error: formal type {name} cannot have formal parameters.")
+					error(ntype, "Type Error: formal type `{name}` cannot have formal parameters.")
 				end
 
 				res = p
@@ -259,11 +274,11 @@ class ModelBuilder
 			var arity = ntype.n_types.length
 			if arity != mclass.arity then
 				if arity == 0 then
-					error(ntype, "Type error: '{name}' is a generic class.")
+					error(ntype, "Type Error: `{mclass.signature_to_s}` is a generic class.")
 				else if mclass.arity == 0 then
-					error(ntype, "Type error: '{name}' is not a generic class.")
+					error(ntype, "Type Error: `{name}` is not a generic class.")
 				else
-					error(ntype, "Type error: '{name}' has {mclass.arity} parameters ({arity} are provided).")
+					error(ntype, "Type Error: expected {mclass.arity} formal argument(s) for `{mclass.signature_to_s}`; got {arity}.")
 				end
 				return null
 			end
@@ -287,7 +302,7 @@ class ModelBuilder
 		end
 
 		# If everything fail, then give up :(
-		error(ntype, "Type error: class {name} not found in module {mmodule}.")
+		error(ntype, "Error: class `{name}` not found in module `{mmodule}`.")
 		return null
 	end
 
@@ -314,7 +329,7 @@ class ModelBuilder
 				var anchor
 				if mclassdef != null then anchor = mclassdef.bound_mtype else anchor = null
 				if not check_subtype(nt, mmodule, anchor, mt, bound) then
-					error(nt, "Type error: expected {bound}, got {mt}")
+					error(nt, "Type Error: expected `{bound}`, got `{mt}`.")
 					return null
 				end
 			end
@@ -344,6 +359,22 @@ class ModelBuilder
 	end
 end
 
+redef class ANode
+	# The indication that the node did not pass some semantic verifications.
+	#
+	# This simple flag is set by a given analysis to say that the node is broken and unusable in
+	# an execution.
+	# When a node status is set to broken, it is usually associated with a error message.
+	#
+	# If it is safe to do so, clients of the AST SHOULD just skip broken nodes in their processing.
+	# Clients that do not care about the executability (e.g. metrics) MAY still process the node or
+	# perform specific checks to determinate the validity of the node.
+	#
+	# Note that the broken status is not propagated to parent or children nodes.
+	# e.g. a broken expression used as argument does not make the whole call broken.
+	var is_broken = false is writable
+end
+
 redef class AType
 	# The mtype associated to the node
 	var mtype: nullable MType = null