From a1f7764bca6dd333f9dc6913ee213b22829d824b Mon Sep 17 00:00:00 2001
From: David Majnemer <david.majnemer@gmail.com>
Date: Sun, 22 May 2016 05:34:26 +0000
Subject: [PATCH] [AST] Cleanup comments regarding CXXRecordDecl::isEmpty
We were missing references to the standard, some of our home-grown
verbiage didn't make any sense.
No functional change is intended.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@270353 91177308-0d34-0410-b5e6-96231b3b80d8
---
include/clang/AST/DeclCXX.h | 7 ++++---
lib/AST/DeclCXX.cpp | 19 +++++++++++--------
2 files changed, 15 insertions(+), 11 deletions(-)
diff --git a/include/clang/AST/DeclCXX.h b/include/clang/AST/DeclCXX.h
index cd1e1d6b8d8..a5cf9ca9926 100644
--- a/include/clang/AST/DeclCXX.h
+++ b/include/clang/AST/DeclCXX.h
@@ -1139,9 +1139,10 @@ public:
/// \brief Determine whether this is an empty class in the sense of
/// (C++11 [meta.unary.prop]).
///
- /// A non-union class is empty iff it has a virtual function, virtual base,
- /// data member (other than 0-width bit-field) or inherits from a non-empty
- /// class.
+ /// The CXXRecordDecl is a class type, but not a union type,
+ /// with no non-static data members other than bit-fields of length 0,
+ /// no virtual member functions, no virtual base classes,
+ /// and no base class B for which is_empty<B>::value is false.
///
/// \note This does NOT include a check for union-ness.
bool isEmpty() const { return data().Empty; }
diff --git a/lib/AST/DeclCXX.cpp b/lib/AST/DeclCXX.cpp
index 9dc0771eadb..45205e8b201 100644
--- a/lib/AST/DeclCXX.cpp
+++ b/lib/AST/DeclCXX.cpp
@@ -172,8 +172,6 @@ CXXRecordDecl::setBases(CXXBaseSpecifier const * const *Bases,
CXXRecordDecl *BaseClassDecl
= cast<CXXRecordDecl>(BaseType->getAs<RecordType>()->getDecl());
- // A class with a non-empty base class is not empty.
- // FIXME: Standard ref?
if (!BaseClassDecl->isEmpty()) {
if (!data().Empty) {
// C++0x [class]p7:
@@ -187,6 +185,9 @@ CXXRecordDecl::setBases(CXXBaseSpecifier const * const *Bases,
data().IsStandardLayout = false;
}
+ // C++14 [meta.unary.prop]p4:
+ // T is a class type [...] with [...] no base class B for which
+ // is_empty<B>::value is false.
data().Empty = false;
data().HasNoNonEmptyBases = false;
}
@@ -238,9 +239,9 @@ CXXRecordDecl::setBases(CXXBaseSpecifier const * const *Bases,
if (SeenVBaseTypes.insert(C.getCanonicalType(BaseType)).second)
VBases.push_back(Base);
- // C++11 [meta.unary.prop] is_empty:
- // T is a class type, but not a union type, with ... no virtual base
- // classes
+ // C++14 [meta.unary.prop] is_empty:
+ // T is a class type, but not a union type, with ... no virtual base
+ // classes
data().Empty = false;
// C++1z [dcl.init.agg]p1:
@@ -458,8 +459,8 @@ void CXXRecordDecl::addedMember(Decl *D) {
// A POD-struct is an aggregate class...
data().PlainOldData = false;
- // Virtual functions make the class non-empty.
- // FIXME: Standard ref?
+ // C++14 [meta.unary.prop]p4:
+ // T is a class type [...] with [...] no virtual member functions...
data().Empty = false;
// C++ [class.virtual]p1:
@@ -938,7 +939,9 @@ void CXXRecordDecl::addedMember(Decl *D) {
if (!data().HasNoNonEmptyBases)
data().IsStandardLayout = false;
- // If this is not a zero-length bit-field, then the class is not empty.
+ // C++14 [meta.unary.prop]p4:
+ // T is a class type [...] with [...] no non-static data members other
+ // than bit-fields of length 0...
if (data().Empty) {
if (!Field->isBitField() ||
(!Field->getBitWidth()->isTypeDependent() &&
--
GitLab