From: Alexis Laferrière <alexis.laf@xymus.net>
Date: Thu, 18 Jun 2015 14:25:53 +0000 (-0400)
Subject: src/frontend: add a phase to validate regular expression
X-Git-Tag: v0.7.6~22^2~1
X-Git-Url: http://nitlanguage.org

src/frontend: add a phase to validate regular expression

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
---

diff --git a/src/frontend/frontend.nit b/src/frontend/frontend.nit
index 68ea75b..42cbccd 100644
--- a/src/frontend/frontend.nit
+++ b/src/frontend/frontend.nit
@@ -27,6 +27,7 @@ import check_annotation
 import glsl_validation
 import parallelization_phase
 import i18n_phase
+import regex_phase
 
 redef class ToolContext
 	# FIXME: there is conflict in linex in nitc, so use this trick to force invocation
diff --git a/src/frontend/regex_phase.nit b/src/frontend/regex_phase.nit
new file mode 100644
index 0000000..feafa77
--- /dev/null
+++ b/src/frontend/regex_phase.nit
@@ -0,0 +1,74 @@
+# 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.
+
+# Check for error in regular expressions from string literals
+module regex_phase
+
+private import parser_util
+private import literal
+import modelize
+
+redef class ToolContext
+
+	# Phase checking for errors in regex
+	var regex_phase: Phase = new RegexPhase(self, [literal_phase])
+end
+
+private class RegexPhase
+	super Phase
+
+	redef fun process_nmodule(nmodule)
+	do
+		var visitor = new RegexVisitor(toolcontext)
+		nmodule.accept_regex_visitor visitor
+	end
+end
+
+private class RegexVisitor
+	super Visitor
+
+	var toolcontext: ToolContext
+
+	redef fun visit(n) do n.accept_regex_visitor(self)
+end
+
+redef class ANode
+	private fun accept_regex_visitor(v: RegexVisitor) do visit_all v
+end
+
+redef class ACallExpr
+
+	redef fun accept_regex_visitor(v)
+	do
+		var method = n_id
+		var receiver = n_expr
+
+		# Check only string literals on which `to_re` is called
+		if method.text == "to_re" and receiver isa AStringFormExpr then
+
+			# Retrieve regex source
+			var re_src = receiver.value
+			if re_src == null then return
+
+			# Check for errors by compiling it right now
+			var re = re_src.to_re
+			var error = re.compile
+			re.finalize
+
+			if error != null then
+				v.toolcontext.error(self.location, "Regex Error: " + error.to_s)
+			end
+		end
+	end
+end