[clang-tools-extra] r285752 - [clang-tidy] Handle bitfields in cppcoreguidelines-pro-type-member-init

[Malcolm Parsons via cfe-commits]

Author: malcolm.parsons
Date: Tue Nov  1 16:26:53 2016
New Revision: 285752

URL: http://llvm.org/viewvc/llvm-project?rev=285752&view=rev
Log:
[clang-tidy] Handle bitfields in cppcoreguidelines-pro-type-member-init

Summary:
Unnamed bitfields cannot be initialized.
Bitfields cannot be in-class initialized.

Reviewers: alexfh, hokein, aaron.ballman

Subscribers: Prazek, nemanjai, cfe-commits

Differential Revision: https://reviews.llvm.org/D26119

Modified:
    clang-tools-extra/trunk/clang-tidy/cppcoreguidelines/ProTypeMemberInitCheck.cpp
    clang-tools-extra/trunk/test/clang-tidy/cppcoreguidelines-pro-type-member-init.cpp

Modified: clang-tools-extra/trunk/clang-tidy/cppcoreguidelines/ProTypeMemberInitCheck.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/cppcoreguidelines/ProTypeMemberInitCheck.cpp?rev=285752&r1=285751&r2=285752&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/cppcoreguidelines/ProTypeMemberInitCheck.cpp (original)
+++ clang-tools-extra/trunk/clang-tidy/cppcoreguidelines/ProTypeMemberInitCheck.cpp Tue Nov  1 16:26:53 2016
@@ -358,7 +358,7 @@ void ProTypeMemberInitCheck::checkMissin
     if (!F->hasInClassInitializer() &&
         utils::type_traits::isTriviallyDefaultConstructible(F->getType(),
                                                             Context) &&
-        !isEmpty(Context, F->getType()))
+        !isEmpty(Context, F->getType()) && !F->isUnnamedBitfield())
       FieldsToInit.insert(F);
   });
   if (FieldsToInit.empty())
@@ -407,7 +407,9 @@ void ProTypeMemberInitCheck::checkMissin
   SmallPtrSet<const FieldDecl *, 16> FieldsToFix;
   forEachField(ClassDecl, FieldsToInit, true, [&](const FieldDecl *F) {
     // Don't suggest fixes for enums because we don't know a good default.
-    if (!F->getType()->isEnumeralType())
+    // Don't suggest fixes for bitfields because in-class initialization is not
+    // possible.
+    if (!F->getType()->isEnumeralType() && !F->isBitField())
       FieldsToFix.insert(F);
   });
   if (FieldsToFix.empty())

Modified: clang-tools-extra/trunk/test/clang-tidy/cppcoreguidelines-pro-type-member-init.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/cppcoreguidelines-pro-type-member-init.cpp?rev=285752&r1=285751&r2=285752&view=diff
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/cppcoreguidelines-pro-type-member-init.cpp (original)
+++ clang-tools-extra/trunk/test/clang-tidy/cppcoreguidelines-pro-type-member-init.cpp Tue Nov  1 16:26:53 2016
@@ -456,3 +456,20 @@ template <typename T> class NoCrash {
     template <typename U> B(U u) {}
   };
 };
+
+struct PositiveBitfieldMember {
+  PositiveBitfieldMember() {}
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: constructor does not initialize these fields: F
+  unsigned F : 5;
+};
+
+struct NegativeUnnamedBitfieldMember {
+  NegativeUnnamedBitfieldMember() {}
+  unsigned : 5;
+};
+
+struct NegativeInitializedBitfieldMembers {
+  NegativeInitializedBitfieldMembers() : F(3) { G = 2; }
+  unsigned F : 5;
+  unsigned G : 5;
+};