Implement #243

src/analysis/config.d

@@ -92,4 +92,7 @@ struct StaticAnalysisConfig
 
 	@INI("Checks for redundant parenthesis")
 	bool redundant_parens_check;
+
+	@INI("Checks for labels with the same name as variables")
+	bool label_var_same_name_check;
 }

src/analysis/label_var_same_name_check.d

@@ -0,0 +1,119 @@
+// Distributed under the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE_1_0.txt or copy at
+//          http://www.boost.org/LICENSE_1_0.txt)
+
+module analysis.label_var_same_name_check;
+
+import std.d.ast;
+import std.d.lexer;
+
+import analysis.base;
+import analysis.helpers;
+
+/**
+ * Checks for labels and variables that have the same name.
+ */
+class LabelVarNameCheck : BaseAnalyzer
+{
+	this(string fileName)
+	{
+		super(fileName);
+	}
+
+	override void visit(const Module mod)
+	{
+		pushScope();
+		mod.accept(this);
+		popScope();
+	}
+
+	override void visit(const BlockStatement block)
+	{
+		pushScope();
+		block.accept(this);
+		popScope();
+	}
+
+	override void visit(const StructBody structBody)
+	{
+		pushScope();
+		structBody.accept(this);
+		popScope();
+	}
+
+	override void visit(const VariableDeclaration var)
+	{
+		foreach (dec; var.declarators)
+			duplicateCheck(dec.name, false);
+	}
+
+	override void visit(const LabeledStatement labeledStatement)
+	{
+		duplicateCheck(labeledStatement.identifier, true);
+		if (labeledStatement.declarationOrStatement !is null)
+			labeledStatement.declarationOrStatement.accept(this);
+	}
+
+	alias visit = BaseAnalyzer.visit;
+
+private:
+
+	Thing[string][] stack;
+
+	void duplicateCheck(const Token name, bool fromLabel)
+	{
+		import std.conv : to;
+		const(Thing)* thing = name.text in currentScope;
+		if (thing is null)
+			currentScope[name.text] = Thing(name.text, name.line, name.column, false);
+		else
+		{
+			immutable thisKind = fromLabel ? "Label" : "Variable";
+			immutable otherKind = thing.isVar ? "variable" : "label";
+			addErrorMessage(name.line, name.column, "dscanner.suspicious.label_var_same_name",
+				thisKind ~ " \"" ~ name.text ~ "\" has the same name as a "
+				~ otherKind ~ " defined on line " ~ to!string(thing.line) ~ ".");
+		}
+	}
+
+	static struct Thing
+	{
+		string name;
+		size_t line;
+		size_t column;
+		bool isVar;
+	}
+
+	ref currentScope() @property
+	{
+		return stack[$-1];
+	}
+
+	void pushScope()
+	{
+		stack.length++;
+	}
+
+	void popScope()
+	{
+		stack.length--;
+	}
+}
+
+unittest
+{
+	import analysis.config : StaticAnalysisConfig;
+	import std.stdio : stderr;
+
+	StaticAnalysisConfig sac;
+	sac.label_var_same_name_check = true;
+	assertAnalyzerWarnings(q{
+unittest
+{
+blah:
+	int blah; // [warn]: Variable "blah" has the same name as a label defined on line 4.
+}
+int blah;
+	}c, sac);
+	stderr.writeln("Unittest for LabelVarNameCheck passed.");
+}

src/analysis/run.d

@@ -43,6 +43,7 @@ import analysis.local_imports;
 import analysis.unmodified;
 import analysis.if_statements;
 import analysis.redundant_parens;
+import analysis.label_var_same_name_check;
 
 bool first = true;
 
@@ -196,6 +197,7 @@ MessageSet analyze(string fileName, const Module m,
 	if (analysisConfig.local_import_check) checks ~= new LocalImportCheck(fileName);
 	if (analysisConfig.could_be_immutable_check) checks ~= new UnmodifiedFinder(fileName);
 	if (analysisConfig.redundant_parens_check) checks ~= new RedundantParenCheck(fileName);
+	if (analysisConfig.label_var_same_name_check) checks ~= new LabelVarNameCheck(fileName);
 	version(none) if (analysisConfig.redundant_if_check) checks ~= new IfStatementCheck(fileName);
 
 	foreach (check; checks)

src/analysis/unused_label.d

@@ -4,7 +4,6 @@
 
 module analysis.unused_label;
 
-import std.stdio;
 import std.d.ast;
 import std.d.lexer;
 import analysis.base;
@@ -19,39 +18,11 @@ class UnusedLabelCheck : BaseAnalyzer
 		super(fileName);
 	}
 
-	static struct Label
+	override void visit(const Module mod)
 	{
-		string name;
+		pushScope();
-		size_t line;
+		mod.accept(this);
-		size_t column;
+		popScope();
-		bool used;
-	}
-
-	Label[string][] stack;
-
-	auto ref current() @property
-	{
-		return stack[$-1];
-	}
-
-	void pushScope()
-	{
-		stack.length++;
-	}
-
-	void popScope()
-	{
-		foreach (label; current.byValue())
-		{
-			assert(label.line != size_t.max && label.column != size_t.max);
-			if (!label.used)
-			{
-				addErrorMessage(label.line, label.column,
-					"dscanner.suspicious.unused_label",
-					"Label \"" ~ label.name ~ "\" is not used.");
-			}
-		}
-		stack.length--;
 	}
 
 	override void visit(const FunctionBody functionBody)
@@ -99,15 +70,6 @@ class UnusedLabelCheck : BaseAnalyzer
 			labeledStatement.declarationOrStatement.accept(this);
 	}
 
-	void labelUsed(string name)
-	{
-		Label* entry = name in current;
-		if (entry is null)
-			current[name] = Label(name, size_t.max, size_t.max, true);
-		else
-			entry.used = true;
-	}
-
 	override void visit(const ContinueStatement contStatement)
 	{
 		if (contStatement.label.text.length)
@@ -123,11 +85,58 @@ class UnusedLabelCheck : BaseAnalyzer
 		if (gotoStatement.label.text.length)
 			labelUsed(gotoStatement.label.text);
 	}
+
+private:
+
+	static struct Label
+	{
+		string name;
+		size_t line;
+		size_t column;
+		bool used;
+	}
+
+	Label[string][] stack;
+
+	auto ref current() @property
+	{
+		return stack[$-1];
+	}
+
+	void pushScope()
+	{
+		stack.length++;
+	}
+
+	void popScope()
+	{
+		foreach (label; current.byValue())
+		{
+			assert(label.line != size_t.max && label.column != size_t.max);
+			if (!label.used)
+			{
+				addErrorMessage(label.line, label.column,
+					"dscanner.suspicious.unused_label",
+					"Label \"" ~ label.name ~ "\" is not used.");
+			}
+		}
+		stack.length--;
+	}
+
+	void labelUsed(string name)
+	{
+		Label* entry = name in current;
+		if (entry is null)
+			current[name] = Label(name, size_t.max, size_t.max, true);
+		else
+			entry.used = true;
+	}
 }
 
 unittest
 {
 	import analysis.config : StaticAnalysisConfig;
+	import std.stdio : stderr;
 
 	StaticAnalysisConfig sac;
 	sac.unused_label_check = true;