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

diff --git a/src/interpreter/naive_interpreter.nit b/src/interpreter/naive_interpreter.nit
index 34530b7..eced30f 100644
--- a/src/interpreter/naive_interpreter.nit
+++ b/src/interpreter/naive_interpreter.nit
@@ -119,7 +119,10 @@ class NaiveInterpreter
 	var escapemark: nullable EscapeMark = null
 
 	# The count of `catch` blocs that have been encountered and can catch an abort
-	var catch_count = 0
+	var catch_count = 0 is writable
+
+	# The last error thrown on abort/runtime error where catch_count > 0
+	var last_error: nullable FatalError = null
 
 	# Is a return or a break or a continue executed?
 	# Use this function to know if you must skip the evaluation of statements
@@ -685,15 +688,25 @@ class NaiveInterpreter
 	var error_instance = new MutableInstance(modelbuilder.model.null_type) is lazy
 end
 
+# A runtime error
+class FatalError
+	# The error message
+	var message: String
+
+	# The problematic node, if any
+	var node: nullable ANode
+end
+
 # An instance represents a value of the executed program.
 abstract class Instance
 	# The dynamic type of the instance
 	# ASSERT: not self.mtype.is_anchored
 	var mtype: MType
 
-	# return true if the instance is the true value.
-	# return false if the instance is the true value.
-	# else aborts
+	# Return `true` if the instance is the `true` value.
+	#
+	# Return `false` if the instance is the `false` value.
+	# Abort if the instance is not a boolean value.
 	fun is_true: Bool do abort
 
 	# Return true if `self` IS `o` (using the Nit semantic of is)
@@ -748,7 +761,7 @@ class MutableInstance
 end
 
 # Special instance to handle primitives values (int, bool, etc.)
-# The trick it just to encapsulate the <<real>> value
+# The trick is just to encapsulate the “real” value.
 class PrimitiveInstance[E]
 	super Instance
 
@@ -820,6 +833,12 @@ redef class ANode
 	# `v` is used to know if a colored message is displayed or not
 	fun fatal(v: NaiveInterpreter, message: String)
 	do
+		# Abort if there is a `catch` block
+		if v.catch_count > 0 then
+			v.last_error = new FatalError(message, self)
+			abort
+		end
+
 		if v.modelbuilder.toolcontext.opt_no_color.value == true then
 			sys.stderr.write("Runtime error: {message} ({location.file.filename}:{location.line_start})\n")
 		else
@@ -1174,9 +1193,9 @@ redef class AMethPropdef
 				var ns = recvval.fast_cstring(args[1].to_i)
 				return v.c_string_instance(ns.to_s)
 			else if pname == "fetch_4_chars" then
-				return v.int_instance(args[0].val.as(CString).fetch_4_chars(args[1].to_i))
+				return v.uint32_instance(args[0].val.as(CString).fetch_4_chars(args[1].to_i))
 			else if pname == "fetch_4_hchars" then
-				return v.int_instance(args[0].val.as(CString).fetch_4_hchars(args[1].to_i))
+				return v.uint32_instance(args[0].val.as(CString).fetch_4_hchars(args[1].to_i))
 			else if pname == "utf8_length" then
 				return v.int_instance(args[0].val.as(CString).utf8_length(args[1].to_i, args[2].to_i))
 			end
@@ -1688,13 +1707,8 @@ end
 redef class AAbortExpr
 	redef fun stmt(v)
 	do
-		# Abort as asked if there is no `catch` bloc
-		if v.catch_count <= 0 then
-			fatal(v, "Aborted")
-			exit(1)
-		else
-			abort
-		end
+		fatal(v, "Aborted")
+		exit(1)
 	end
 end