Added a Sizeof check (see Alice coding guidelines)

Author: sawenzel

aliceO2/AliceO2TidyModule.cpp

@@ -11,6 +11,7 @@
 #include "../ClangTidyModule.h"
 #include "../ClangTidyModuleRegistry.h"
 #include "MemberNamesCheck.h"
+#include "SizeofCheck.h"
 
 namespace clang {
 namespace tidy {
@@ -20,6 +21,8 @@ class AliceO2Module : public ClangTidyModule {
 public:
   void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
     CheckFactories.registerCheck<MemberNamesCheck>("aliceO2-member-name");
+    CheckFactories.registerCheck<SizeofCheck>(
+        "aliceO2-SizeOf");
   }
 };
 

aliceO2/CMakeLists.txt

@@ -3,6 +3,7 @@ set(LLVM_LINK_COMPONENTS support)
 add_clang_library(clangTidyAliceO2Module
   AliceO2TidyModule.cpp
   MemberNamesCheck.cpp
+  SizeofCheck.cpp
 
   LINK_LIBS
   clangAST

aliceO2/SizeofCheck.cpp

@@ -0,0 +1,49 @@
+//===--- SizeofCheck.cpp - clang-tidy--------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SizeofCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace aliceO2 {
+
+void SizeofCheck::registerMatchers(MatchFinder *Finder) {
+  // matches sizeof + alignof
+  Finder->addMatcher(unaryExprOrTypeTraitExpr().bind("unaryexp"), this);
+}
+
+void SizeofCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *Expr = Result.Nodes.getNodeAs<UnaryExprOrTypeTraitExpr>("unaryexp");
+  const auto Kind = Expr->getKind();
+  if (Kind != UETT_SizeOf){
+    return;
+  }
+
+  // is argument of sizeof a Type?
+  if (Expr->isArgumentType()) {
+    diag(Expr->getLocStart(), "consider using sizeof() on instance instead on direct type");
+    return;
+  }
+
+  // we found a correct expression; check if it uses parens
+  if (dyn_cast<ParenExpr>(Expr->getArgumentExpr())) {
+    return;
+  }
+
+  // no parens -> issue warning
+  diag(Expr->getLocStart(), "consider using parens () for arguments to sizeof");
+}
+
+} // namespace aliceO2
+} // namespace tidy
+} // namespace clang

aliceO2/SizeofCheck.h

@@ -0,0 +1,35 @@
+//===--- SizeofCheck.h - clang-tidy------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALICEO2_SIZEOF_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALICEO2_SIZEOF_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace aliceO2 {
+
+/// FIXME: Write a short description.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/aliceO2-SizeOf.html
+class SizeofCheck : public ClangTidyCheck {
+public:
+  SizeofCheck(StringRef Name, ClangTidyContext *Context)
+      : ClangTidyCheck(Name, Context) {}
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace aliceO2
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALICEO2_SIZEOF_H