[clang-tidy: modernize] Fix modernize-use-equals-default with {} brackets list initialization: patch

[IdrissRio]

Summary

Hello, i would like to suggest a fix for one of the checks in clang-tidy.
The bug was reported in https://bugs.llvm.org/show_bug.cgi?id=38039 where you can find more information.

struct UOB{
	UOB(const UOB &Other):j{Other.j}{}
	int j;
};

In this case the check modernize-use-equals-default does not detect copy constructors that can be defaulted; that should be:

struct UOB{
	UOB(const UOB &Other) = default;
	int j;
};

[aaron.ballman]

LGTM with a formatting nit.

clang-tidy/modernize/UseEqualsDefaultCheck.cpp

100

Did clang-format produce this formatting? If not, can you clang-format this patch?

[IdrissRio]

Fixed the formatting error with clang-format

clang-tidy/modernize/UseEqualsDefaultCheck.cpp

static bool isCopyConstructorAndCanBeDefaulted(ASTContext *Context,
   for (const auto *Field : FieldsToInit) {
     auto AccessToFieldInParam = accessToFieldInVar(Field, Param);
     // The initialization is a CXXConstructExpr for class types.
     if (match(
             cxxConstructorDecl(forEachConstructorInitializer(cxxCtorInitializer(
                 isMemberInitializer(), forField(equalsNode(Field)),
                 withInitializer(anyOf(
                     AccessToFieldInParam,
+                    initListExpr(has(AccessToFieldInParam)),
                     cxxConstructExpr(allOf(
                         hasDeclaration(cxxConstructorDecl(isCopyConstructor())),
                         argumentCountIs(1),
                         hasArgument(0, AccessToFieldInParam)))))))),
             *Ctor, *Context)
             .empty())
       return false;
   }

test/clang-tidy/modernize-use-equals-default-copy.cpp

_type &operator=(const _type &rhs) {      \
       return *this;                           \
     }                                         \
     _base value;                              \
   };
 
 STRUCT_WITH_COPY_ASSIGN(unsigned char, Hex8CopyAssign)
 // CHECK-MESSAGES: :[[@LINE-1]]:1: warning: use '= default' to define a trivial copy-assignment operator
 // CHECK-MESSAGES: :[[@LINE-9]]:40: note:
+
+// Use of braces
+struct UOB{
+  UOB(const UOB &Other):j{Other.j}{}
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: use '= default' to define a trivial copy constructor [modernize-use-equals-default]
+  // CHECK-FIXES: UOB(const UOB &Other)= default;
+  int j;
+};