https://github.com/MitalAshok created
https://github.com/llvm/llvm-project/pull/91990
Fix `CXXRecordDecl::isParsingBaseSpecifiers` so that it is true while parsing
base specifiers instead of directly after they have been parsed.
-fcomplete-member-pointers now issues a diagnostic when a member pointer is
used in a base specifier.
-fcomplete-member-pointers has also been relaxed to not issue a diagnostic for
incomplete classes with an explicit `__{single|multiple|virtual}_inheritance`
attribute, whose completeness would not affect the representation of
pointer-to-member objects.
>From a5347082aa47a7aa525ece818f91fb6fdd5fdb0c Mon Sep 17 00:00:00 2001
From: Mital Ashok <mi...@mitalashok.co.uk>
Date: Mon, 13 May 2024 16:59:06 +0100
Subject: [PATCH] [Clang] Fix Microsoft ABI inheritance model when member
pointer is used in a base specifier
Fix CXXRecordDecl::isParsingBaseSpecifiers so that it is true while parsing
base specifiers instead of directly after they have been parsed.
-fcomplete-member-pointers now issues a diagnostic when a member pointer is
used in a base specifier.
-fcomplete-member-pointers has also been relaxed to not issue a diagnostic for
incomplete classes with an explicit __{single|multiple|virtual}_inheritance
attribute, whose completeness would not affect the representation of
pointer-to-member objects.
---
clang/docs/ReleaseNotes.rst | 4 ++++
clang/include/clang/AST/DeclCXX.h | 5 ++--
.../clang/Basic/DiagnosticSemaKinds.td | 2 ++
clang/lib/AST/DeclCXX.cpp | 6 +----
clang/lib/Parse/ParseDeclCXX.cpp | 22 +++++++++++++++++
clang/lib/Sema/SemaDeclCXX.cpp | 3 ---
clang/lib/Sema/SemaType.cpp | 23 +++++++++++-------
.../test/SemaCXX/complete-member-pointers.cpp | 24 ++++++++++++++++++-
clang/test/SemaCXX/member-pointer-ms.cpp | 8 +++++++
9 files changed, 77 insertions(+), 20 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 4702b8c10cdbb..054332c2cee4e 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -79,6 +79,10 @@ ABI Changes in This Version
- Fixed Microsoft calling convention when returning classes that have a deleted
copy assignment operator. Such a class should be returned indirectly.
+- Fixed Microsoft layout of pointer-to-members of classes when the layout is
needed
+ directly or indirectly by the base classes of a class. These should use the
most
+ general unspecified inheritance layout. Also affects
-fcomplete-member-pointers.
+
AST Dumping Potentially Breaking Changes
----------------------------------------
diff --git a/clang/include/clang/AST/DeclCXX.h
b/clang/include/clang/AST/DeclCXX.h
index fb52ac804849d..45b3b47ed51c5 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -297,7 +297,8 @@ class CXXRecordDecl : public RecordDecl {
LLVM_PREFERRED_TYPE(bool)
unsigned IsLambda : 1;
- /// Whether we are currently parsing base specifiers.
+ /// Whether we are currently parsing base specifiers; the
+ /// colon has been consumed but the beginning left brace hasn't.
LLVM_PREFERRED_TYPE(bool)
unsigned IsParsingBaseSpecifiers : 1;
@@ -598,7 +599,7 @@ class CXXRecordDecl : public RecordDecl {
return !hasDefinition() || !isDynamicClass() || hasAnyDependentBases();
}
- void setIsParsingBaseSpecifiers() { data().IsParsingBaseSpecifiers = true; }
+ void setIsParsingBaseSpecifiers(bool to = true) {
data().IsParsingBaseSpecifiers = to; }
bool isParsingBaseSpecifiers() const {
return data().IsParsingBaseSpecifiers;
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td
b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 9e82130c93609..a9f9f02651cff 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -8003,6 +8003,8 @@ def err_bad_memptr_rhs : Error<
def err_bad_memptr_lhs : Error<
"left hand operand to %0 must be a %select{|pointer to }1class "
"compatible with the right hand operand, but is %2">;
+def note_memptr_incomplete_until_bases : Note<
+ "this will affect the ABI of the member pointer until the bases have been
specified">;
def err_memptr_incomplete : Error<
"member pointer has incomplete base type %0">;
def warn_exception_caught_by_earlier_handler : Warning<
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index 75c441293d62e..7f20a47e6a054 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -474,10 +474,8 @@ CXXRecordDecl::setBases(CXXBaseSpecifier const * const
*Bases,
if (data().IsStandardLayout && NumBases > 1 && hasRepeatedBaseClass(this))
data().IsStandardLayout = false;
- if (VBases.empty()) {
- data().IsParsingBaseSpecifiers = false;
+ if (VBases.empty())
return;
- }
// Create base specifier for any direct or indirect virtual bases.
data().VBases = new (C) CXXBaseSpecifier[VBases.size()];
@@ -488,8 +486,6 @@ CXXRecordDecl::setBases(CXXBaseSpecifier const * const
*Bases,
addedClassSubobject(Type->getAsCXXRecordDecl());
data().getVBases()[I] = *VBases[I];
}
-
- data().IsParsingBaseSpecifiers = false;
}
unsigned CXXRecordDecl::getODRHash() const {
diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index 65ddebca49bc6..681b9803142c2 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -2334,6 +2334,26 @@ void Parser::ParseClassSpecifier(tok::TokenKind
TagTokKind,
}
}
+namespace {
+ struct ParsingBaseSpecifiersGuard {
+ CXXRecordDecl *RD = nullptr;
+ ParsingBaseSpecifiersGuard(Sema& S, Decl *D) {
+ if (D) {
+ S.AdjustDeclIfTemplate(D);
+ RD = cast<CXXRecordDecl>(D);
+ assert(!RD->isParsingBaseSpecifiers() && "Recursively parsing base
specifiers of the same class?");
+ RD->setIsParsingBaseSpecifiers(true);
+ }
+ }
+ ~ParsingBaseSpecifiersGuard() {
+ if (RD) {
+ assert(RD->isParsingBaseSpecifiers() && "Stopped parsing base
specifiers before exiting ParseBaseClause?");
+ RD->setIsParsingBaseSpecifiers(false);
+ }
+ }
+ };
+}
+
/// ParseBaseClause - Parse the base-clause of a C++ class [C++ class.derived].
///
/// base-clause : [C++ class.derived]
@@ -2345,6 +2365,8 @@ void Parser::ParseBaseClause(Decl *ClassDecl) {
assert(Tok.is(tok::colon) && "Not a base clause");
ConsumeToken();
+ ParsingBaseSpecifiersGuard Guard(Actions, ClassDecl);
+
// Build up an array of parsed base specifiers.
SmallVector<CXXBaseSpecifier *, 8> BaseInfo;
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 53238d355ea09..0bf7208605213 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -2862,9 +2862,6 @@ BaseResult Sema::ActOnBaseSpecifier(Decl *classdecl,
SourceRange SpecifierRange,
if (!Class)
return true;
- // We haven't yet attached the base specifiers.
- Class->setIsParsingBaseSpecifiers();
-
// We do not support any C++11 attributes on base-specifiers yet.
// Diagnose any attributes we see.
for (const ParsedAttr &AL : Attributes) {
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index fddc3545ecb61..0a801f1797d23 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -9463,17 +9463,22 @@ bool Sema::RequireCompleteTypeImpl(SourceLocation Loc,
QualType T,
if (const MemberPointerType *MPTy = T->getAs<MemberPointerType>()) {
if (!MPTy->getClass()->isDependentType()) {
- if (getLangOpts().CompleteMemberPointers &&
- !MPTy->getClass()->getAsCXXRecordDecl()->isBeingDefined() &&
- RequireCompleteType(Loc, QualType(MPTy->getClass(), 0), Kind,
- diag::err_memptr_incomplete))
- return true;
-
// We lock in the inheritance model once somebody has asked us to ensure
// that a pointer-to-member type is complete.
- if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
- (void)isCompleteType(Loc, QualType(MPTy->getClass(), 0));
- assignInheritanceModel(*this, MPTy->getMostRecentCXXRecordDecl());
+ if (Context.getTargetInfo().getCXXABI().isMicrosoft() ||
getLangOpts().CompleteMemberPointers) {
+ QualType Class = QualType(MPTy->getClass(), 0);
+ (void)isCompleteType(Loc, Class);
+ CXXRecordDecl *RD = MPTy->getMostRecentCXXRecordDecl();
+ assignInheritanceModel(*this, RD);
+
+ if (getLangOpts().CompleteMemberPointers &&
RD->getMSInheritanceModel() == MSInheritanceModel::Unspecified) {
+ if (RD->hasDefinition() && RD->isParsingBaseSpecifiers()) {
+ Diag(Loc, diag::err_memptr_incomplete) << Class;
+ Diag(RD->getDefinition()->getLocation(),
diag::note_memptr_incomplete_until_bases);
+ } else if (!RequireCompleteType(Loc, Class,
diag::err_memptr_incomplete))
+ Diag(Loc, diag::err_memptr_incomplete) << Class;
+ return true;
+ }
}
}
}
diff --git a/clang/test/SemaCXX/complete-member-pointers.cpp
b/clang/test/SemaCXX/complete-member-pointers.cpp
index 942bb703a9223..41c9b98438c1a 100644
--- a/clang/test/SemaCXX/complete-member-pointers.cpp
+++ b/clang/test/SemaCXX/complete-member-pointers.cpp
@@ -1,4 +1,6 @@
-// RUN: %clang_cc1 -verify -fsyntax-only -fcomplete-member-pointers %s
+// RUN: %clang_cc1 -verify -fsyntax-only -fc++-abi=itanium -fms-extensions
-fcomplete-member-pointers %s
+// RUN: %clang_cc1 -verify -fsyntax-only -triple=x86_64-unknown-win32
-fc++-abi=microsoft -fms-compatibility -fcomplete-member-pointers %s
+// RUN: %clang_cc1 -verify -fsyntax-only -triple=x86_64-unknown-win32
-fc++-abi=itanium -fms-compatibility -fcomplete-member-pointers %s
struct S; // expected-note {{forward declaration of 'S'}}
typedef int S::*t;
@@ -13,3 +15,23 @@ template <typename T>
struct S3 {
int T::*foo;
};
+
+struct __single_inheritance S4;
+int S4::* baz;
+
+template<int I> struct Base {};
+struct __single_inheritance S5 : Base<sizeof(int S5::*)> {};
+struct
+S6 // #S6
+:
+Base<sizeof(int S6::*)>
+// expected-error@-1 {{member pointer has incomplete base type 'S6'}}
+// expected-note@#S6 {{this will affect the ABI of the member pointer until
the bases have been specified}}
+{
+};
+
+template<typename T> struct S7 {};
+int S7<void>::* qux; // #qux
+template<> struct S7<void> {};
+// expected-error@-1 {{explicit specialization of 'S7<void>' after
instantiation}}
+// expected-note@#qux {{implicit instantiation first required here}}
diff --git a/clang/test/SemaCXX/member-pointer-ms.cpp
b/clang/test/SemaCXX/member-pointer-ms.cpp
index 3271ff0c623a2..efbab8b28498f 100644
--- a/clang/test/SemaCXX/member-pointer-ms.cpp
+++ b/clang/test/SemaCXX/member-pointer-ms.cpp
@@ -215,6 +215,14 @@ struct NewUnspecified;
SingleTemplate<void (IncSingle::*)()> tmpl_single;
UnspecTemplate<void (NewUnspecified::*)()> tmpl_unspec;
+// Member pointers used in base specifiers force an unspecified inheritance
model
+struct MemPtrInBase : UnspecTemplate<void (MemPtrInBase::*)()> {};
+#ifdef VMB
+struct __single_inheritance SpecifiedMemPtrInBase;
+struct SpecifiedMemPtrInBase : SingleTemplate<void
(SpecifiedMemPtrInBase::*)()> {};
+struct __single_inheritance SpecifiedMemPtrInBase2 : SingleTemplate<void
(SpecifiedMemPtrInBase2::*)()> {};
+#endif
+
struct NewUnspecified { };
static_assert(sizeof(void (NewUnspecified::*)()) == kUnspecifiedFunctionSize,
"");
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