src: create groups for related things

[nit.git] / src / frontend / simple_misc_analysis.nit

diff --git a/src/frontend/simple_misc_analysis.nit b/src/frontend/simple_misc_analysis.nit
new file mode 100644 (file)
index 0000000..26d6710
--- /dev/null
+++ b/src/frontend/simple_misc_analysis.nit
@@ -0,0 +1,184 @@
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Copyright 2012 Jean Privat <jean@pryen.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.
+
+# Simple vavious processing on a AST
+# The analysis warns on :
+#  * superfluous parentheses
+#  * nested "once" expressions
+#  * use of "while true" instead of "loop"
+module simple_misc_analysis
+
+import phase
+
+redef class ToolContext
+       var simple_misc_analysis_phase: Phase = new SimpleMiscAnalysisPhase(self, null)
+end
+
+private class SimpleMiscAnalysisPhase
+       super Phase
+       redef fun process_nmodule(nmodule) do nmodule.do_simple_misc_analysis(toolcontext)
+end
+
+redef class AModule
+       # Visit the module to detect easy warnings that does not need the metamodel or the importation
+       # Warnings are displayed on the toolcontext
+       fun do_simple_misc_analysis(toolcontext: ToolContext)
+       do
+               var v = new SimpleMiscVisitor(toolcontext)
+               v.enter_visit(self)
+       end
+end
+
+private class SimpleMiscVisitor
+       super Visitor
+       redef fun visit(n)
+       do
+               n.accept_simple_misc(self)
+       end
+
+       # Number of nested once
+       var once_count: Int = 0
+
+       var toolcontext: ToolContext
+
+       fun warning(node: ANode, msg: String)
+       do
+               toolcontext.warning(node.hot_location, msg)
+       end
+
+       init(toolcontext: ToolContext)
+       do
+               self.toolcontext = toolcontext
+       end
+end
+
+
+###############################################################################
+
+redef class ANode
+       private fun accept_simple_misc(v: SimpleMiscVisitor)
+       do
+               visit_all(v)
+               after_simple_misc(v)
+       end
+       private fun after_simple_misc(v: SimpleMiscVisitor) do end
+end
+
+redef class ASignature
+       redef fun after_simple_misc(v)
+       do
+               if self.n_opar != null and self.n_params.is_empty then
+                       v.warning(self, "Warning: superfluous parentheses.")
+               end
+       end
+end
+
+redef class AExpr
+       # Warn in case of superfluous parentheses
+       private fun warn_parentheses(v: SimpleMiscVisitor) do end
+end
+
+redef class AParExpr
+       redef fun warn_parentheses(v)
+       do
+               v.warning(self, "Warning: superfluous parentheses.")
+       end
+end
+
+redef class AParExprs
+       redef fun after_simple_misc(v)
+       do
+               if n_exprs.is_empty then
+                       v.warning(self, "Warning: superfluous parentheses.")
+               end
+       end
+end
+
+redef class AReturnExpr
+       redef fun after_simple_misc(v)
+       do
+               var e = n_expr
+               if e != null then
+                       e.warn_parentheses(v)
+               end
+       end
+end
+
+redef class AContinueExpr
+       redef fun after_simple_misc(v)
+       do
+               var e = n_expr
+               if e != null then
+                       e.warn_parentheses(v)
+               end
+       end
+end
+
+redef class ABreakExpr
+       redef fun after_simple_misc(v)
+       do
+               var e = n_expr
+               if e != null then
+                       e.warn_parentheses(v)
+               end
+       end
+end
+
+redef class AWhileExpr
+       redef fun after_simple_misc(v)
+       do
+               if n_expr isa ATrueExpr then
+                       v.warning(self, "Warning: use 'loop' instead of 'while true do'.")
+               else
+                       n_expr.warn_parentheses(v)
+               end
+       end
+end
+
+redef class AForExpr
+       redef fun after_simple_misc(v)
+       do
+               n_expr.warn_parentheses(v)
+       end
+end
+
+redef class AIfExpr
+       redef fun after_simple_misc(v)
+       do
+               n_expr.warn_parentheses(v)
+       end
+end
+
+redef class AIfexprExpr
+       redef fun after_simple_misc(v)
+       do
+               n_expr.warn_parentheses(v)
+       end
+end
+
+redef class AOnceExpr
+       redef fun accept_simple_misc(v)
+       do
+               if v.once_count > 0 then
+                       v.warning(self, "Useless once in a once expression.")
+               end
+               v.once_count = v.once_count + 1
+
+               super
+
+               v.once_count = v.once_count - 1
+       end
+end