[clang-tidy] hicpp bitwise operations on signed integers

Summary:
This check implements the rule [[ http://www.codingstandard.com/section/5-6-shift-operators/ | 5.6. HIC++ ]]
that forbidds bitwise operations on signed integer types.

Reviewers: aaron.ballman, hokein, alexfh, Eugene.Zelenko

Reviewed By: aaron.ballman

Subscribers: cfe-commits, mgorny, JDevlieghere, xazax.hun

Differential Revision: https://reviews.llvm.org/D36586

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@312122 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 96 insertions, 0 deletions

diff --git a/clang-tidy/hicpp/CMakeLists.txt b/clang-tidy/hicpp/CMakeLists.txt
index e5e70955..fd15d485 100644
--- a/clang-tidy/hicpp/CMakeLists.txt
+++ b/clang-tidy/hicpp/CMakeLists.txt
@@ -4,6 +4,7 @@ add_clang_library(clangTidyHICPPModule
   ExceptionBaseclassCheck.cpp
   NoAssemblerCheck.cpp
   HICPPTidyModule.cpp
+  SignedBitwiseCheck.cpp
 
   LINK_LIBS
   clangAST
diff --git a/clang-tidy/hicpp/HICPPTidyModule.cpp b/clang-tidy/hicpp/HICPPTidyModule.cpp
index 321d8791..f7b70d2b 100644
--- a/clang-tidy/hicpp/HICPPTidyModule.cpp
+++ b/clang-tidy/hicpp/HICPPTidyModule.cpp
@@ -26,6 +26,7 @@
 #include "../readability/IdentifierNamingCheck.h"
 #include "ExceptionBaseclassCheck.h"
 #include "NoAssemblerCheck.h"
+#include "SignedBitwiseCheck.h"
 
 namespace clang {
 namespace tidy {
@@ -38,6 +39,8 @@ public:
         "hicpp-braces-around-statements");
     CheckFactories.registerCheck<ExceptionBaseclassCheck>(
         "hicpp-exception-baseclass");
+    CheckFactories.registerCheck<SignedBitwiseCheck>(
+        "hicpp-signed-bitwise");
     CheckFactories.registerCheck<google::ExplicitConstructorCheck>(
         "hicpp-explicit-conversions");
     CheckFactories.registerCheck<readability::FunctionSizeCheck>(
diff --git a/clang-tidy/hicpp/SignedBitwiseCheck.cpp b/clang-tidy/hicpp/SignedBitwiseCheck.cpp
new file mode 100644
index 00000000..acd7216a
--- /dev/null
+++ b/clang-tidy/hicpp/SignedBitwiseCheck.cpp
@@ -0,0 +1,56 @@
+//===--- SignedBitwiseCheck.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 "SignedBitwiseCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+using namespace clang::ast_matchers::internal;
+
+namespace clang {
+namespace tidy {
+namespace hicpp {
+
+void SignedBitwiseCheck::registerMatchers(MatchFinder *Finder) {
+  const auto SignedIntegerOperand =
+      expr(ignoringImpCasts(hasType(isSignedInteger()))).bind("signed_operand");
+
+  // Match binary bitwise operations on signed integer arguments.
+  Finder->addMatcher(
+      binaryOperator(allOf(anyOf(hasOperatorName("|"), hasOperatorName("&"),
+                                 hasOperatorName("^"), hasOperatorName("<<"),
+                                 hasOperatorName(">>")),
+                           hasEitherOperand(SignedIntegerOperand)))
+          .bind("binary_signed"),
+      this);
+
+  // Match unary operations on signed integer types.
+  Finder->addMatcher(unaryOperator(allOf(hasOperatorName("~"),
+                                         hasUnaryOperand(SignedIntegerOperand)))
+                         .bind("unary_signed"),
+                     this);
+}
+
+void SignedBitwiseCheck::check(const MatchFinder::MatchResult &Result) {
+  const ast_matchers::BoundNodes &N = Result.Nodes;
+  const auto *SignedBinary = N.getNodeAs<BinaryOperator>("binary_signed");
+  const auto *SignedUnary = N.getNodeAs<UnaryOperator>("unary_signed");
+  const auto *SignedOperand = N.getNodeAs<Expr>("signed_operand");
+
+  const bool IsUnary = SignedUnary != nullptr;
+  diag(IsUnary ? SignedUnary->getLocStart() : SignedBinary->getLocStart(),
+       "use of a signed integer operand with a %select{binary|unary}0 bitwise "
+       "operator")
+      << IsUnary << SignedOperand->getSourceRange();
+}
+
+} // namespace hicpp
+} // namespace tidy
+} // namespace clang
diff --git a/clang-tidy/hicpp/SignedBitwiseCheck.h b/clang-tidy/hicpp/SignedBitwiseCheck.h
new file mode 100644
index 00000000..24338ad9
--- /dev/null
+++ b/clang-tidy/hicpp/SignedBitwiseCheck.h
@@ -0,0 +1,36 @@
+//===--- SignedBitwiseCheck.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_HICPP_SIGNED_BITWISE_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_HICPP_SIGNED_BITWISE_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace hicpp {
+
+/// This check implements the rule 5.6.1 of the HICPP Standard, which disallows
+/// bitwise operations on signed integer types.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/hicpp-signed-bitwise.html
+class SignedBitwiseCheck : public ClangTidyCheck {
+public:
+  SignedBitwiseCheck(StringRef Name, ClangTidyContext *Context)
+      : ClangTidyCheck(Name, Context) {}
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace hicpp
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_HICPP_SIGNED_BITWISE_H