r275417 - Diagnose taking address and reference binding of packed members
Richard Smith via cfe-commits
cfe-commits at lists.llvm.org
Thu Jul 14 17:18:18 PDT 2016
It appears that GCC accepts that case. More generally, it looks like GCC
suppresses the warning when the reference is a function parameter (any
function, not just a copy constructor or similar). I'm not sure if that's
an intentional feature or a bug, but it should be pretty easy for us to be
compatible with, at least...
On Thu, Jul 14, 2016 at 5:03 PM, Reid Kleckner <rnk at google.com> wrote:
> I wonder if GCC accepts this:
>
> In file included from ../../net/tools/quic/quic_epoll_clock_test.cc:7:
> In file included from
> ../../net/tools/quic/test_tools/mock_epoll_server.h:16:
> In file included from ../../net/tools/epoll_server/epoll_server.h:41:
> ../../build/linux/debian_wheezy_amd64-sysroot/usr/include/x86_64-linux-gnu/sys/epoll.h:89:8:
> error: binding reference to packed member 'data' of class or structure
> 'epoll_event'
> struct epoll_event
> ^~~~~~~~~~~
> ../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/stl_pair.h:267:14:
> note: in instantiation of function template specialization 'std::pair<long,
> epoll_event>::pair<long, epoll_event>' requested here
> return __pair_type(std::forward<_T1>(__x), std::forward<_T2>(__y));
> ^
> ../../net/tools/quic/test_tools/mock_epoll_server.h:69:30: note: in
> instantiation of function template specialization 'std::make_pair<long &,
> const epoll_event &>' requested here
> event_queue_.insert(std::make_pair(time_in_usec, ee));
>
> On Thu, Jul 14, 2016 at 4:54 PM, Richard Smith <richard at metafoo.co.uk>
> wrote:
>
>> On Thu, Jul 14, 2016 at 3:52 PM, Reid Kleckner via cfe-commits <
>> cfe-commits at lists.llvm.org> wrote:
>>
>>> Why did we upgrade the unaligned reference binding from a warning to an
>>> error? That will make it hard to roll this change out across many codebases.
>>>
>>
>> GCC has given an error on this since version 4.7. If there are cases that
>> GCC accepts and we reject, that sounds like a bug.
>>
>>
>>> On Thu, Jul 14, 2016 at 7:10 AM, Roger Ferrer Ibanez via cfe-commits <
>>> cfe-commits at lists.llvm.org> wrote:
>>>
>>>> Author: rogfer01
>>>> Date: Thu Jul 14 09:10:43 2016
>>>> New Revision: 275417
>>>>
>>>> URL: http://llvm.org/viewvc/llvm-project?rev=275417&view=rev
>>>> Log:
>>>> Diagnose taking address and reference binding of packed members
>>>>
>>>> This patch implements PR#22821.
>>>>
>>>> Taking the address of a packed member is dangerous since the reduced
>>>> alignment of the pointee is lost. This can lead to memory alignment
>>>> faults in some architectures if the pointer value is dereferenced.
>>>>
>>>> This change adds a new warning to clang emitted when taking the address
>>>> of a packed member. A packed member is either a field/data member
>>>> declared as attribute((packed)) or belonging to a struct/class
>>>> declared as such. The associated flag is -Waddress-of-packed-member.
>>>> Conversions (either implicit or via a valid casting) to pointer types
>>>> with lower or equal alignment requirements (e.g. void* or char*)
>>>> silence the warning.
>>>>
>>>> This change also adds a new error diagnostic when the user attempts to
>>>> bind a reference to a packed member, regardless of the alignment.
>>>>
>>>> Differential Revision: https://reviews.llvm.org/D20561
>>>>
>>>>
>>>>
>>>> Added:
>>>> cfe/trunk/test/Sema/address-packed-member-memops.c
>>>> cfe/trunk/test/Sema/address-packed.c
>>>> cfe/trunk/test/SemaCXX/address-packed-member-memops.cpp
>>>> cfe/trunk/test/SemaCXX/address-packed.cpp
>>>> Modified:
>>>> cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>>>> cfe/trunk/include/clang/Sema/Sema.h
>>>> cfe/trunk/lib/Sema/SemaCast.cpp
>>>> cfe/trunk/lib/Sema/SemaChecking.cpp
>>>> cfe/trunk/lib/Sema/SemaExpr.cpp
>>>> cfe/trunk/lib/Sema/SemaInit.cpp
>>>>
>>>> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=275417&r1=275416&r2=275417&view=diff
>>>>
>>>> ==============================================================================
>>>> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
>>>> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Thu Jul 14
>>>> 09:10:43 2016
>>>> @@ -5425,6 +5425,11 @@ def warn_pointer_indirection_from_incomp
>>>> "dereference of type %1 that was reinterpret_cast from type %0 has
>>>> undefined "
>>>> "behavior">,
>>>> InGroup<UndefinedReinterpretCast>, DefaultIgnore;
>>>> +def warn_taking_address_of_packed_member : Warning<
>>>> + "taking address of packed member %0 of class or structure %q1 may
>>>> result in an unaligned pointer value">,
>>>> + InGroup<DiagGroup<"address-of-packed-member">>;
>>>> +def err_binding_reference_to_packed_member : Error<
>>>> + "binding reference to packed member %0 of class or structure %q1">;
>>>>
>>>> def err_objc_object_assignment : Error<
>>>> "cannot assign to class object (%0 invalid)">;
>>>>
>>>> Modified: cfe/trunk/include/clang/Sema/Sema.h
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=275417&r1=275416&r2=275417&view=diff
>>>>
>>>> ==============================================================================
>>>> --- cfe/trunk/include/clang/Sema/Sema.h (original)
>>>> +++ cfe/trunk/include/clang/Sema/Sema.h Thu Jul 14 09:10:43 2016
>>>> @@ -9518,6 +9518,10 @@ private:
>>>> void CheckArgumentWithTypeTag(const ArgumentWithTypeTagAttr *Attr,
>>>> const Expr * const *ExprArgs);
>>>>
>>>> + /// \brief Check if we are taking the address of a packed field
>>>> + /// as this may be a problem if the pointer value is dereferenced.
>>>> + void CheckAddressOfPackedMember(Expr *rhs);
>>>> +
>>>> /// \brief The parser's current scope.
>>>> ///
>>>> /// The parser maintains this state here.
>>>> @@ -9596,6 +9600,51 @@ public:
>>>> // Emitting members of dllexported classes is delayed until the class
>>>> // (including field initializers) is fully parsed.
>>>> SmallVector<CXXRecordDecl*, 4> DelayedDllExportClasses;
>>>> +
>>>> +private:
>>>> + /// \brief Helper class that collects misaligned member designations
>>>> and
>>>> + /// their location info for delayed diagnostics.
>>>> + struct MisalignedMember {
>>>> + Expr *E;
>>>> + RecordDecl *RD;
>>>> + ValueDecl *MD;
>>>> + CharUnits Alignment;
>>>> +
>>>> + MisalignedMember() : E(), RD(), MD(), Alignment() {}
>>>> + MisalignedMember(Expr *E, RecordDecl *RD, ValueDecl *MD,
>>>> + CharUnits Alignment)
>>>> + : E(E), RD(RD), MD(MD), Alignment(Alignment) {}
>>>> + explicit MisalignedMember(Expr *E)
>>>> + : MisalignedMember(E, nullptr, nullptr, CharUnits()) {}
>>>> +
>>>> + bool operator==(const MisalignedMember &m) { return this->E ==
>>>> m.E; }
>>>> + };
>>>> + /// \brief Small set of gathered accesses to potentially misaligned
>>>> members
>>>> + /// due to the packed attribute.
>>>> + SmallVector<MisalignedMember, 4> MisalignedMembers;
>>>> +
>>>> + /// \brief Adds an expression to the set of gathered misaligned
>>>> members.
>>>> + void AddPotentialMisalignedMembers(Expr *E, RecordDecl *RD,
>>>> ValueDecl *MD,
>>>> + CharUnits Alignment);
>>>> +
>>>> +public:
>>>> + /// \brief Diagnoses the current set of gathered accesses. This
>>>> typically
>>>> + /// happens at full expression level. The set is cleared after
>>>> emitting the
>>>> + /// diagnostics.
>>>> + void DiagnoseMisalignedMembers();
>>>> +
>>>> + /// \brief This function checks if the expression is in the sef of
>>>> potentially
>>>> + /// misaligned members and it is converted to some pointer type T
>>>> with lower
>>>> + /// or equal alignment requirements. If so it removes it. This is
>>>> used when
>>>> + /// we do not want to diagnose such misaligned access (e.g. in
>>>> conversions to void*).
>>>> + void DiscardMisalignedMemberAddress(const Type *T, Expr *E);
>>>> +
>>>> + /// \brief This function calls Action when it determines that E
>>>> designates a
>>>> + /// misaligned member due to the packed attribute. This is used to
>>>> emit
>>>> + /// local diagnostics like in reference binding.
>>>> + void RefersToMemberWithReducedAlignment(
>>>> + Expr *E,
>>>> + std::function<void(Expr *, RecordDecl *, ValueDecl *,
>>>> CharUnits)> Action);
>>>> };
>>>>
>>>> /// \brief RAII object that enters a new expression evaluation context.
>>>>
>>>> Modified: cfe/trunk/lib/Sema/SemaCast.cpp
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaCast.cpp?rev=275417&r1=275416&r2=275417&view=diff
>>>>
>>>> ==============================================================================
>>>> --- cfe/trunk/lib/Sema/SemaCast.cpp (original)
>>>> +++ cfe/trunk/lib/Sema/SemaCast.cpp Thu Jul 14 09:10:43 2016
>>>> @@ -256,6 +256,7 @@ Sema::BuildCXXNamedCast(SourceLocation O
>>>> Op.CheckConstCast();
>>>> if (Op.SrcExpr.isInvalid())
>>>> return ExprError();
>>>> + DiscardMisalignedMemberAddress(DestType.getTypePtr(), E);
>>>> }
>>>> return Op.complete(CXXConstCastExpr::Create(Context, Op.ResultType,
>>>> Op.ValueKind, Op.SrcExpr.get(),
>>>> DestTInfo,
>>>> @@ -279,6 +280,7 @@ Sema::BuildCXXNamedCast(SourceLocation O
>>>> Op.CheckReinterpretCast();
>>>> if (Op.SrcExpr.isInvalid())
>>>> return ExprError();
>>>> + DiscardMisalignedMemberAddress(DestType.getTypePtr(), E);
>>>> }
>>>> return Op.complete(CXXReinterpretCastExpr::Create(Context,
>>>> Op.ResultType,
>>>> Op.ValueKind, Op.Kind,
>>>> Op.SrcExpr.get(),
>>>> @@ -291,6 +293,7 @@ Sema::BuildCXXNamedCast(SourceLocation O
>>>> Op.CheckStaticCast();
>>>> if (Op.SrcExpr.isInvalid())
>>>> return ExprError();
>>>> + DiscardMisalignedMemberAddress(DestType.getTypePtr(), E);
>>>> }
>>>>
>>>> return Op.complete(CXXStaticCastExpr::Create(Context,
>>>> Op.ResultType,
>>>>
>>>> Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=275417&r1=275416&r2=275417&view=diff
>>>>
>>>> ==============================================================================
>>>> --- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
>>>> +++ cfe/trunk/lib/Sema/SemaChecking.cpp Thu Jul 14 09:10:43 2016
>>>> @@ -8302,6 +8302,8 @@ void CheckImplicitConversion(Sema &S, Ex
>>>>
>>>> DiagnoseNullConversion(S, E, T, CC);
>>>>
>>>> + S.DiscardMisalignedMemberAddress(Target, E);
>>>> +
>>>> if (!Source->isIntegerType() || !Target->isIntegerType())
>>>> return;
>>>>
>>>> @@ -9371,6 +9373,7 @@ void Sema::CheckCompletedExpr(Expr *E, S
>>>> CheckUnsequencedOperations(E);
>>>> if (!IsConstexpr && !E->isValueDependent())
>>>> CheckForIntOverflow(E);
>>>> + DiagnoseMisalignedMembers();
>>>> }
>>>>
>>>> void Sema::CheckBitFieldInitialization(SourceLocation InitLoc,
>>>> @@ -10916,3 +10919,67 @@ void Sema::CheckArgumentWithTypeTag(cons
>>>> << ArgumentExpr->getSourceRange()
>>>> << TypeTagExpr->getSourceRange();
>>>> }
>>>> +
>>>> +void Sema::AddPotentialMisalignedMembers(Expr *E, RecordDecl *RD,
>>>> ValueDecl *MD,
>>>> + CharUnits Alignment) {
>>>> + MisalignedMembers.emplace_back(E, RD, MD, Alignment);
>>>> +}
>>>> +
>>>> +void Sema::DiagnoseMisalignedMembers() {
>>>> + for (MisalignedMember &m : MisalignedMembers) {
>>>> + Diag(m.E->getLocStart(),
>>>> diag::warn_taking_address_of_packed_member)
>>>> + << m.MD << m.RD << m.E->getSourceRange();
>>>> + }
>>>> + MisalignedMembers.clear();
>>>> +}
>>>> +
>>>> +void Sema::DiscardMisalignedMemberAddress(const Type *T, Expr *E) {
>>>> + if (!T->isPointerType())
>>>> + return;
>>>> + if (isa<UnaryOperator>(E) &&
>>>> + cast<UnaryOperator>(E)->getOpcode() == UO_AddrOf) {
>>>> + auto *Op = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens();
>>>> + if (isa<MemberExpr>(Op)) {
>>>> + auto MA = std::find(MisalignedMembers.begin(),
>>>> MisalignedMembers.end(),
>>>> + MisalignedMember(Op));
>>>> + if (MA != MisalignedMembers.end() &&
>>>> + Context.getTypeAlignInChars(T->getPointeeType()) <=
>>>> MA->Alignment)
>>>> + MisalignedMembers.erase(MA);
>>>> + }
>>>> + }
>>>> +}
>>>> +
>>>> +void Sema::RefersToMemberWithReducedAlignment(
>>>> + Expr *E,
>>>> + std::function<void(Expr *, RecordDecl *, ValueDecl *, CharUnits)>
>>>> Action) {
>>>> + const auto *ME = dyn_cast<MemberExpr>(E);
>>>> + while (ME && isa<FieldDecl>(ME->getMemberDecl())) {
>>>> + QualType BaseType = ME->getBase()->getType();
>>>> + if (ME->isArrow())
>>>> + BaseType = BaseType->getPointeeType();
>>>> + RecordDecl *RD = BaseType->getAs<RecordType>()->getDecl();
>>>> +
>>>> + ValueDecl *MD = ME->getMemberDecl();
>>>> + bool ByteAligned =
>>>> Context.getTypeAlignInChars(MD->getType()).isOne();
>>>> + if (ByteAligned) // Attribute packed does not have any effect.
>>>> + break;
>>>> +
>>>> + if (!ByteAligned &&
>>>> + (RD->hasAttr<PackedAttr>() || (MD->hasAttr<PackedAttr>()))) {
>>>> + CharUnits Alignment =
>>>> std::min(Context.getTypeAlignInChars(MD->getType()),
>>>> +
>>>> Context.getTypeAlignInChars(BaseType));
>>>> + // Notify that this expression designates a member with reduced
>>>> alignment
>>>> + Action(E, RD, MD, Alignment);
>>>> + break;
>>>> + }
>>>> + ME = dyn_cast<MemberExpr>(ME->getBase());
>>>> + }
>>>> +}
>>>> +
>>>> +void Sema::CheckAddressOfPackedMember(Expr *rhs) {
>>>> + using namespace std::placeholders;
>>>> + RefersToMemberWithReducedAlignment(
>>>> + rhs, std::bind(&Sema::AddPotentialMisalignedMembers,
>>>> std::ref(*this), _1,
>>>> + _2, _3, _4));
>>>> +}
>>>> +
>>>>
>>>> Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=275417&r1=275416&r2=275417&view=diff
>>>>
>>>> ==============================================================================
>>>> --- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
>>>> +++ cfe/trunk/lib/Sema/SemaExpr.cpp Thu Jul 14 09:10:43 2016
>>>> @@ -6001,7 +6001,9 @@ Sema::ActOnCastExpr(Scope *S, SourceLoca
>>>> CheckTollFreeBridgeCast(castType, CastExpr);
>>>>
>>>> CheckObjCBridgeRelatedCast(castType, CastExpr);
>>>> -
>>>> +
>>>> + DiscardMisalignedMemberAddress(castType.getTypePtr(), CastExpr);
>>>> +
>>>> return BuildCStyleCastExpr(LParenLoc, castTInfo, RParenLoc,
>>>> CastExpr);
>>>> }
>>>>
>>>> @@ -10534,6 +10536,8 @@ QualType Sema::CheckAddressOfOperand(Exp
>>>> if (op->getType()->isObjCObjectType())
>>>> return Context.getObjCObjectPointerType(op->getType());
>>>>
>>>> + CheckAddressOfPackedMember(op);
>>>> +
>>>> return Context.getPointerType(op->getType());
>>>> }
>>>>
>>>>
>>>> Modified: cfe/trunk/lib/Sema/SemaInit.cpp
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaInit.cpp?rev=275417&r1=275416&r2=275417&view=diff
>>>>
>>>> ==============================================================================
>>>> --- cfe/trunk/lib/Sema/SemaInit.cpp (original)
>>>> +++ cfe/trunk/lib/Sema/SemaInit.cpp Thu Jul 14 09:10:43 2016
>>>> @@ -6457,6 +6457,15 @@ InitializationSequence::Perform(Sema &S,
>>>> ExtendingEntity->getDecl());
>>>>
>>>> CheckForNullPointerDereference(S, CurInit.get());
>>>> +
>>>> + S.RefersToMemberWithReducedAlignment(CurInit.get(), [&](Expr *E,
>>>> +
>>>> RecordDecl *RD,
>>>> +
>>>> ValueDecl *MD,
>>>> +
>>>> CharUnits) {
>>>> + S.Diag(Kind.getLocation(),
>>>> diag::err_binding_reference_to_packed_member)
>>>> + << MD << RD << E->getSourceRange();
>>>> + });
>>>> +
>>>> break;
>>>>
>>>> case SK_BindReferenceToTemporary: {
>>>> @@ -6645,12 +6654,16 @@ InitializationSequence::Perform(Sema &S,
>>>> getAssignmentAction(Entity), CCK);
>>>> if (CurInitExprRes.isInvalid())
>>>> return ExprError();
>>>> +
>>>> + S.DiscardMisalignedMemberAddress(Step->Type.getTypePtr(),
>>>> CurInit.get());
>>>> +
>>>> CurInit = CurInitExprRes;
>>>>
>>>> if (Step->Kind == SK_ConversionSequenceNoNarrowing &&
>>>> S.getLangOpts().CPlusPlus &&
>>>> !CurInit.get()->isValueDependent())
>>>> DiagnoseNarrowingInInitList(S, *Step->ICS, SourceType,
>>>> Entity.getType(),
>>>> CurInit.get());
>>>> +
>>>> break;
>>>> }
>>>>
>>>>
>>>> Added: cfe/trunk/test/Sema/address-packed-member-memops.c
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/address-packed-member-memops.c?rev=275417&view=auto
>>>>
>>>> ==============================================================================
>>>> --- cfe/trunk/test/Sema/address-packed-member-memops.c (added)
>>>> +++ cfe/trunk/test/Sema/address-packed-member-memops.c Thu Jul 14
>>>> 09:10:43 2016
>>>> @@ -0,0 +1,26 @@
>>>> +// RUN: %clang_cc1 -fsyntax-only -verify %s
>>>> +// expected-no-diagnostics
>>>> +
>>>> +struct B {
>>>> + int x, y, z, w;
>>>> +} b;
>>>> +
>>>> +struct __attribute__((packed)) A {
>>>> + struct B b;
>>>> +} a;
>>>> +
>>>> +typedef __typeof__(sizeof(int)) size_t;
>>>> +
>>>> +void *memcpy(void *dest, const void *src, size_t n);
>>>> +int memcmp(const void *s1, const void *s2, size_t n);
>>>> +void *memmove(void *dest, const void *src, size_t n);
>>>> +void *memset(void *s, int c, size_t n);
>>>> +
>>>> +int x;
>>>> +
>>>> +void foo(void) {
>>>> + memcpy(&a.b, &b, sizeof(b));
>>>> + memmove(&a.b, &b, sizeof(b));
>>>> + memset(&a.b, 0, sizeof(b));
>>>> + x = memcmp(&a.b, &b, sizeof(b));
>>>> +}
>>>>
>>>> Added: cfe/trunk/test/Sema/address-packed.c
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/address-packed.c?rev=275417&view=auto
>>>>
>>>> ==============================================================================
>>>> --- cfe/trunk/test/Sema/address-packed.c (added)
>>>> +++ cfe/trunk/test/Sema/address-packed.c Thu Jul 14 09:10:43 2016
>>>> @@ -0,0 +1,160 @@
>>>> +// RUN: %clang_cc1 -fsyntax-only -verify %s
>>>> +extern void f1(int *);
>>>> +extern void f2(char *);
>>>> +
>>>> +struct Ok {
>>>> + char c;
>>>> + int x;
>>>> +};
>>>> +
>>>> +struct __attribute__((packed)) Arguable {
>>>> + char c0;
>>>> + int x;
>>>> + char c1;
>>>> +};
>>>> +
>>>> +union __attribute__((packed)) UnionArguable {
>>>> + char c;
>>>> + int x;
>>>> +};
>>>> +
>>>> +typedef struct Arguable ArguableT;
>>>> +
>>>> +struct Arguable *get_arguable();
>>>> +
>>>> +void to_void(void *);
>>>> +
>>>> +void g0(void) {
>>>> + {
>>>> + struct Ok ok;
>>>> + f1(&ok.x); // no-warning
>>>> + f2(&ok.c); // no-warning
>>>> + }
>>>> + {
>>>> + struct Arguable arguable;
>>>> + f2(&arguable.c0); // no-warning
>>>> + f1(&arguable.x); // expected-warning {{packed member 'x' of class
>>>> or structure 'Arguable'}}
>>>> + f2(&arguable.c1); // no-warning
>>>> +
>>>> + f1((int *)(void *)&arguable.x); // no-warning
>>>> + to_void(&arguable.x); // no-warning
>>>> + void *p = &arguable.x; // no-warning;
>>>> + to_void(p);
>>>> + }
>>>> + {
>>>> + union UnionArguable arguable;
>>>> + f2(&arguable.c); // no-warning
>>>> + f1(&arguable.x); // expected-warning {{packed member 'x' of class
>>>> or structure 'UnionArguable'}}
>>>> +
>>>> + f1((int *)(void *)&arguable.x); // no-warning
>>>> + to_void(&arguable.x); // no-warning
>>>> + }
>>>> + {
>>>> + ArguableT arguable;
>>>> + f2(&arguable.c0); // no-warning
>>>> + f1(&arguable.x); // expected-warning {{packed member 'x' of class
>>>> or structure 'Arguable'}}
>>>> + f2(&arguable.c1); // no-warning
>>>> +
>>>> + f1((int *)(void *)&arguable.x); // no-warning
>>>> + to_void(&arguable.x); // no-warning
>>>> + }
>>>> + {
>>>> + struct Arguable *arguable = get_arguable();
>>>> + f2(&arguable->c0); // no-warning
>>>> + f1(&arguable->x); // expected-warning {{packed member 'x' of
>>>> class or structure 'Arguable'}}
>>>> + f2(&arguable->c1); // no-warning
>>>> +
>>>> + f1((int *)(void *)&arguable->x); // no-warning
>>>> + to_void(&arguable->c1); // no-warning
>>>> + }
>>>> + {
>>>> + ArguableT *arguable = get_arguable();
>>>> + f2(&(arguable->c0)); // no-warning
>>>> + f1(&(arguable->x)); // expected-warning {{packed member 'x' of
>>>> class or structure 'Arguable'}}
>>>> + f2(&(arguable->c1)); // no-warning
>>>> +
>>>> + f1((int *)(void *)&(arguable->x)); // no-warning
>>>> + to_void(&(arguable->c1)); // no-warning
>>>> + }
>>>> +}
>>>> +
>>>> +struct S1 {
>>>> + char c;
>>>> + int i __attribute__((packed));
>>>> +};
>>>> +
>>>> +int *g1(struct S1 *s1) {
>>>> + return &s1->i; // expected-warning {{packed member 'i' of class or
>>>> structure 'S1'}}
>>>> +}
>>>> +
>>>> +struct S2_i {
>>>> + int i;
>>>> +};
>>>> +struct __attribute__((packed)) S2 {
>>>> + char c;
>>>> + struct S2_i inner;
>>>> +};
>>>> +
>>>> +int *g2(struct S2 *s2) {
>>>> + return &s2->inner.i; // expected-warning {{packed member 'inner' of
>>>> class or structure 'S2'}}
>>>> +}
>>>> +
>>>> +struct S2_a {
>>>> + char c;
>>>> + struct S2_i inner __attribute__((packed));
>>>> +};
>>>> +
>>>> +int *g2_a(struct S2_a *s2_a) {
>>>> + return &s2_a->inner.i; // expected-warning {{packed member 'inner'
>>>> of class or structure 'S2_a'}}
>>>> +}
>>>> +
>>>> +struct __attribute__((packed)) S3 {
>>>> + char c;
>>>> + struct {
>>>> + int i;
>>>> + } inner;
>>>> +};
>>>> +
>>>> +int *g3(struct S3 *s3) {
>>>> + return &s3->inner.i; // expected-warning {{packed member 'inner' of
>>>> class or structure 'S3'}}
>>>> +}
>>>> +
>>>> +struct S4 {
>>>> + char c;
>>>> + struct __attribute__((packed)) {
>>>> + int i;
>>>> + } inner;
>>>> +};
>>>> +
>>>> +int *g4(struct S4 *s4) {
>>>> + return &s4->inner.i; // expected-warning {{packed member 'i' of
>>>> class or structure 'S4::(anonymous)'}}
>>>> +}
>>>> +
>>>> +struct S5 {
>>>> + char c;
>>>> + struct {
>>>> + char c1;
>>>> + int i __attribute__((packed));
>>>> + } inner;
>>>> +};
>>>> +
>>>> +int *g5(struct S5 *s5) {
>>>> + return &s5->inner.i; // expected-warning {{packed member 'i' of
>>>> class or structure 'S5::(anonymous)'}}
>>>> +}
>>>> +
>>>> +struct __attribute__((packed, aligned(2))) AlignedTo2 {
>>>> + int x;
>>>> +};
>>>> +
>>>> +char *g6(struct AlignedTo2 *s) {
>>>> + return (char *)&s->x; // no-warning
>>>> +}
>>>> +
>>>> +struct __attribute__((packed, aligned(2))) AlignedTo2Bis {
>>>> + int x;
>>>> +};
>>>> +
>>>> +struct AlignedTo2Bis* g7(struct AlignedTo2 *s)
>>>> +{
>>>> + return (struct AlignedTo2Bis*)&s->x; // no-warning
>>>> +}
>>>>
>>>> Added: cfe/trunk/test/SemaCXX/address-packed-member-memops.cpp
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/address-packed-member-memops.cpp?rev=275417&view=auto
>>>>
>>>> ==============================================================================
>>>> --- cfe/trunk/test/SemaCXX/address-packed-member-memops.cpp (added)
>>>> +++ cfe/trunk/test/SemaCXX/address-packed-member-memops.cpp Thu Jul 14
>>>> 09:10:43 2016
>>>> @@ -0,0 +1,28 @@
>>>> +// RUN: %clang_cc1 -fsyntax-only -verify %s
>>>> +// expected-no-diagnostics
>>>> +
>>>> +struct B {
>>>> + int x, y, z, w;
>>>> +} b;
>>>> +
>>>> +struct __attribute__((packed)) A {
>>>> + struct B b;
>>>> +} a;
>>>> +
>>>> +typedef __typeof__(sizeof(int)) size_t;
>>>> +
>>>> +extern "C" {
>>>> +void *memcpy(void *dest, const void *src, size_t n);
>>>> +int memcmp(const void *s1, const void *s2, size_t n);
>>>> +void *memmove(void *dest, const void *src, size_t n);
>>>> +void *memset(void *s, int c, size_t n);
>>>> +}
>>>> +
>>>> +int x;
>>>> +
>>>> +void foo() {
>>>> + memcpy(&a.b, &b, sizeof(b));
>>>> + memmove(&a.b, &b, sizeof(b));
>>>> + memset(&a.b, 0, sizeof(b));
>>>> + x = memcmp(&a.b, &b, sizeof(b));
>>>> +}
>>>>
>>>> Added: cfe/trunk/test/SemaCXX/address-packed.cpp
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/address-packed.cpp?rev=275417&view=auto
>>>>
>>>> ==============================================================================
>>>> --- cfe/trunk/test/SemaCXX/address-packed.cpp (added)
>>>> +++ cfe/trunk/test/SemaCXX/address-packed.cpp Thu Jul 14 09:10:43 2016
>>>> @@ -0,0 +1,118 @@
>>>> +// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
>>>> +extern void f1(int *);
>>>> +extern void f2(char *);
>>>> +
>>>> +struct __attribute__((packed)) Arguable {
>>>> + int x;
>>>> + char c;
>>>> + static void foo();
>>>> +};
>>>> +
>>>> +extern void f3(void());
>>>> +
>>>> +namespace Foo {
>>>> +struct __attribute__((packed)) Arguable {
>>>> + char c;
>>>> + int x;
>>>> + static void foo();
>>>> +};
>>>> +}
>>>> +
>>>> +struct Arguable *get_arguable();
>>>> +
>>>> +void f4(int &);
>>>> +
>>>> +void to_void(void *);
>>>> +
>>>> +template <typename... T>
>>>> +void sink(T...);
>>>> +
>>>> +void g0() {
>>>> + {
>>>> + Foo::Arguable arguable;
>>>> + f1(&arguable.x); // expected-warning {{packed member 'x' of
>>>> class or structure 'Foo::Arguable'}}
>>>> + f2(&arguable.c); // no-warning
>>>> + f3(&arguable.foo); // no-warning
>>>> +
>>>> + int &w = arguable.x; // expected-error {{binding reference to
>>>> packed member 'x' of class or structure 'Foo::Arguable'}}
>>>> + sink(w);
>>>> + f4(arguable.x); // expected-error {{binding reference to packed
>>>> member 'x' of class or structure 'Foo::Arguable'}}
>>>> +
>>>> + to_void(&arguable.x); // no-warning
>>>> + void *p1 = &arguable.x; // no-warning
>>>> + void *p2 = static_cast<void *>(&arguable.x); // no-warning
>>>> + void *p3 = reinterpret_cast<void *>(&arguable.x); // no-warning
>>>> + void *p4 = (void *)&arguable.x; // no-warning
>>>> + sink(p1, p2, p3, p4);
>>>> + }
>>>> + {
>>>> + Arguable arguable1;
>>>> + Arguable &arguable(arguable1);
>>>> + f1(&arguable.x); // expected-warning {{packed member 'x' of
>>>> class or structure 'Arguable'}}
>>>> + f2(&arguable.c); // no-warning
>>>> + f3(&arguable.foo); // no-warning
>>>> + }
>>>> + {
>>>> + Arguable *arguable1;
>>>> + Arguable *&arguable(arguable1);
>>>> + f1(&arguable->x); // expected-warning {{packed member 'x' of
>>>> class or structure 'Arguable'}}
>>>> + f2(&arguable->c); // no-warning
>>>> + f3(&arguable->foo); // no-warning
>>>> + }
>>>> +}
>>>> +
>>>> +struct __attribute__((packed)) A {
>>>> + int x;
>>>> + char c;
>>>> +
>>>> + int *f0() {
>>>> + return &this->x; // expected-warning {{packed member 'x' of class
>>>> or structure 'A'}}
>>>> + }
>>>> +
>>>> + int *g0() {
>>>> + return &x; // expected-warning {{packed member 'x' of class or
>>>> structure 'A'}}
>>>> + }
>>>> +
>>>> + char *h0() {
>>>> + return &c; // no-warning
>>>> + }
>>>> +};
>>>> +
>>>> +struct B : A {
>>>> + int *f1() {
>>>> + return &this->x; // expected-warning {{packed member 'x' of class
>>>> or structure 'A'}}
>>>> + }
>>>> +
>>>> + int *g1() {
>>>> + return &x; // expected-warning {{packed member 'x' of class or
>>>> structure 'A'}}
>>>> + }
>>>> +
>>>> + char *h1() {
>>>> + return &c; // no-warning
>>>> + }
>>>> +};
>>>> +
>>>> +template <typename Ty>
>>>> +class __attribute__((packed)) S {
>>>> + Ty X;
>>>> +
>>>> +public:
>>>> + const Ty *get() const {
>>>> + return &X; // expected-warning {{packed member 'X' of class or
>>>> structure 'S<int>'}}
>>>> + // expected-warning at -1 {{packed member 'X' of class or
>>>> structure 'S<float>'}}
>>>> + }
>>>> +};
>>>> +
>>>> +template <typename Ty>
>>>> +void h(Ty *);
>>>> +
>>>> +void g1() {
>>>> + S<int> s1;
>>>> + s1.get(); // expected-note {{in instantiation of member function
>>>> 'S<int>::get'}}
>>>> +
>>>> + S<char> s2;
>>>> + s2.get();
>>>> +
>>>> + S<float> s3;
>>>> + s3.get(); // expected-note {{in instantiation of member function
>>>> 'S<float>::get'}}
>>>> +}
>>>>
>>>>
>>>> _______________________________________________
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>>>> cfe-commits at lists.llvm.org
>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>>>>
>>>
>>>
>>> _______________________________________________
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