r275417 - Diagnose taking address and reference binding of packed members
Reid Kleckner via cfe-commits
cfe-commits at lists.llvm.org
Thu Jul 14 17:03:16 PDT 2016
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'}}
>>> +}
>>>
>>>
>>> _______________________________________________
>>> cfe-commits mailing list
>>> cfe-commits at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>>>
>>
>>
>> _______________________________________________
>> cfe-commits mailing list
>> cfe-commits at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>>
>>
>
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