Reverting 275417

This change has triggered unexpected failures.

llvm-svn: 275462

10 files changed, 1 insertions, 474 deletions

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 5d2e28804c5..664853baebc 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -5425,11 +5425,6 @@ def warn_pointer_indirection_from_incompatible_type : Warning<
   "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)">;
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index ea32162c3dc..6c2c86d6572 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -9518,10 +9518,6 @@ 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.
@@ -9600,51 +9596,6 @@ 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.
diff --git a/clang/lib/Sema/SemaCast.cpp b/clang/lib/Sema/SemaCast.cpp
index e19020c6ade..e83dd071678 100644
--- a/clang/lib/Sema/SemaCast.cpp
+++ b/clang/lib/Sema/SemaCast.cpp
@@ -256,7 +256,6 @@ Sema::BuildCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
       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,
@@ -280,7 +279,6 @@ Sema::BuildCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
       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(),
@@ -293,7 +291,6 @@ Sema::BuildCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
       Op.CheckStaticCast();
       if (Op.SrcExpr.isInvalid())
         return ExprError();
-      DiscardMisalignedMemberAddress(DestType.getTypePtr(), E);
     }
     
     return Op.complete(CXXStaticCastExpr::Create(Context, Op.ResultType,
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index ff18e094bda..ec01b04fcf9 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -8302,8 +8302,6 @@ void CheckImplicitConversion(Sema &S, Expr *E, QualType T,
 
   DiagnoseNullConversion(S, E, T, CC);
 
-  S.DiscardMisalignedMemberAddress(Target, E);
-
   if (!Source->isIntegerType() || !Target->isIntegerType())
     return;
 
@@ -9373,7 +9371,6 @@ void Sema::CheckCompletedExpr(Expr *E, SourceLocation CheckLoc,
   CheckUnsequencedOperations(E);
   if (!IsConstexpr && !E->isValueDependent())
     CheckForIntOverflow(E);
-  DiagnoseMisalignedMembers();
 }
 
 void Sema::CheckBitFieldInitialization(SourceLocation InitLoc,
@@ -10919,67 +10916,3 @@ void Sema::CheckArgumentWithTypeTag(const ArgumentWithTypeTagAttr *Attr,
         << 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));
-}
-
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 2a48798d3cb..0c8a9136948 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -6001,9 +6001,7 @@ Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc,
   CheckTollFreeBridgeCast(castType, CastExpr);
   
   CheckObjCBridgeRelatedCast(castType, CastExpr);
-
-  DiscardMisalignedMemberAddress(castType.getTypePtr(), CastExpr);
-
+  
   return BuildCStyleCastExpr(LParenLoc, castTInfo, RParenLoc, CastExpr);
 }
 
@@ -10536,8 +10534,6 @@ QualType Sema::CheckAddressOfOperand(ExprResult &OrigOp, SourceLocation OpLoc) {
   if (op->getType()->isObjCObjectType())
     return Context.getObjCObjectPointerType(op->getType());
 
-  CheckAddressOfPackedMember(op);
-
   return Context.getPointerType(op->getType());
 }
 
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index c88af08546e..060ee3eef21 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -6457,15 +6457,6 @@ 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: {
@@ -6654,16 +6645,12 @@ 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;
     }
 
diff --git a/clang/test/Sema/address-packed-member-memops.c b/clang/test/Sema/address-packed-member-memops.c
deleted file mode 100644
index 220132f3329..00000000000
--- a/clang/test/Sema/address-packed-member-memops.c
+++ /dev/null
@@ -1,26 +0,0 @@
-// 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));
-}
diff --git a/clang/test/Sema/address-packed.c b/clang/test/Sema/address-packed.c
deleted file mode 100644
index 7c42c6155ee..00000000000
--- a/clang/test/Sema/address-packed.c
+++ /dev/null
@@ -1,160 +0,0 @@
-// 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
-}
diff --git a/clang/test/SemaCXX/address-packed-member-memops.cpp b/clang/test/SemaCXX/address-packed-member-memops.cpp
deleted file mode 100644
index 6614626ae65..00000000000
--- a/clang/test/SemaCXX/address-packed-member-memops.cpp
+++ /dev/null
@@ -1,28 +0,0 @@
-// 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));
-}
diff --git a/clang/test/SemaCXX/address-packed.cpp b/clang/test/SemaCXX/address-packed.cpp
deleted file mode 100644
index 1b4094f4eae..00000000000
--- a/clang/test/SemaCXX/address-packed.cpp
+++ /dev/null
@@ -1,118 +0,0 @@
-// 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@-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'}}
-}