[clang-tidy] Handle bitfields in modernize-use-default-member-init if using C++2a

Summary:
C++2a allows bitfields to have default member initializers.
Add support for this to clang-tidy's modernize-use-default-member-init check.

Reviewers: aaron.ballman, alexfh

Reviewed By: aaron.ballman

Subscribers: klimek, xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D42413

llvm-svn: 323208

diff --git a/clang-tools-extra/clang-tidy/modernize/UseDefaultMemberInitCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseDefaultMemberInitCheck.cpp
index b07f730..c14c685 100644 (file)
--- a/clang-tools-extra/clang-tidy/modernize/UseDefaultMemberInitCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/UseDefaultMemberInitCheck.cpp
@@ -167,7 +167,9 @@ void UseDefaultMemberInitCheck::registerMatchers(MatchFinder *Finder) {
           isDefaultConstructor(), unless(isInstantiated()),
           forEachConstructorInitializer(
               cxxCtorInitializer(
-                  forField(unless(anyOf(isBitField(),
+                  forField(unless(anyOf(getLangOpts().CPlusPlus2a
+                                            ? unless(anything())
+                                            : isBitField(),
                                         hasInClassInitializer(anything()),
                                         hasParent(recordDecl(isUnion()))))),
                   isWritten(), withInitializer(ignoringImplicit(Init)))

diff --git a/clang-tools-extra/test/clang-tidy/modernize-use-default-member-init-bitfield.cpp b/clang-tools-extra/test/clang-tidy/modernize-use-default-member-init-bitfield.cpp
new file mode 100644 (file)
index 0000000..1ff08f9
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/modernize-use-default-member-init-bitfield.cpp
@@ -0,0 +1,10 @@
+// RUN: %check_clang_tidy %s modernize-use-default-member-init %t -- -- -std=c++2a
+
+struct PositiveBitField
+{
+  PositiveBitField() : i(6) {}
+  // CHECK-FIXES: PositiveBitField()  {}
+  int i : 5;
+  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: use default member initializer for 'i' [modernize-use-default-member-init]
+  // CHECK-FIXES: int i : 5{6};
+};