Revert "[clang] add support for -Wpadded on Windows (#130182)"

This reverts commit 76fa953.

Author: asb

clang/docs/ReleaseNotes.rst

@@ -190,8 +190,6 @@ Modified Compiler Flags
 
 - The compiler flag `-fbracket-depth` default value is increased from 256 to 2048. (#GH94728)
 
-- `-Wpadded` option implemented for the `x86_64-windows-msvc` target. Fixes #61702
-
 Removed Compiler Flags
 -------------------------
 

clang/lib/AST/RecordLayoutBuilder.cpp

@@ -2274,9 +2274,9 @@ static unsigned getPaddingDiagFromTagKind(TagTypeKind Tag) {
   }
 }
 
-static void CheckFieldPadding(const ASTContext &Context, bool IsUnion,
-                              uint64_t Offset, uint64_t UnpaddedOffset,
-                              const FieldDecl *D) {
+void ItaniumRecordLayoutBuilder::CheckFieldPadding(
+    uint64_t Offset, uint64_t UnpaddedOffset, uint64_t UnpackedOffset,
+    unsigned UnpackedAlign, bool isPacked, const FieldDecl *D) {
   // We let objc ivars without warning, objc interfaces generally are not used
   // for padding tricks.
   if (isa<ObjCIvarDecl>(D))
@@ -2300,31 +2300,23 @@ static void CheckFieldPadding(const ASTContext &Context, bool IsUnion,
     if (D->getIdentifier()) {
       auto Diagnostic = D->isBitField() ? diag::warn_padded_struct_bitfield
                                         : diag::warn_padded_struct_field;
-      Context.getDiagnostics().Report(D->getLocation(),
-                                      Diagnostic)
+      Diag(D->getLocation(), Diagnostic)
           << getPaddingDiagFromTagKind(D->getParent()->getTagKind())
           << Context.getTypeDeclType(D->getParent()) << PadSize
           << (InBits ? 1 : 0) // (byte|bit)
           << D->getIdentifier();
     } else {
       auto Diagnostic = D->isBitField() ? diag::warn_padded_struct_anon_bitfield
                                         : diag::warn_padded_struct_anon_field;
-      Context.getDiagnostics().Report(D->getLocation(),
-                                      Diagnostic)
+      Diag(D->getLocation(), Diagnostic)
           << getPaddingDiagFromTagKind(D->getParent()->getTagKind())
           << Context.getTypeDeclType(D->getParent()) << PadSize
           << (InBits ? 1 : 0); // (byte|bit)
     }
-  }
-}
-
-void ItaniumRecordLayoutBuilder::CheckFieldPadding(
-    uint64_t Offset, uint64_t UnpaddedOffset, uint64_t UnpackedOffset,
-    unsigned UnpackedAlign, bool isPacked, const FieldDecl *D) {
-  ::CheckFieldPadding(Context, IsUnion, Offset, UnpaddedOffset, D);
-  if (isPacked && Offset != UnpackedOffset) {
-    HasPackedField = true;
-  }
+ }
+ if (isPacked && Offset != UnpackedOffset) {
+   HasPackedField = true;
+ }
 }
 
 static const CXXMethodDecl *computeKeyFunction(ASTContext &Context,
@@ -2650,6 +2642,8 @@ struct MicrosoftRecordLayoutBuilder {
   /// virtual base classes and their offsets in the record.
   ASTRecordLayout::VBaseOffsetsMapTy VBases;
   /// The number of remaining bits in our last bitfield allocation.
+  /// This value isn't meaningful unless LastFieldIsNonZeroWidthBitfield is
+  /// true.
   unsigned RemainingBitsInField;
   bool IsUnion : 1;
   /// True if the last field laid out was a bitfield and was not 0
@@ -3010,15 +3004,6 @@ void MicrosoftRecordLayoutBuilder::layoutField(const FieldDecl *FD) {
   } else {
     FieldOffset = Size.alignTo(Info.Alignment);
   }
-
-  uint64_t UnpaddedFielddOffsetInBits =
-      Context.toBits(DataSize) - RemainingBitsInField;
-
-  ::CheckFieldPadding(Context, IsUnion, Context.toBits(FieldOffset),
-                      UnpaddedFielddOffsetInBits, FD);
-
-  RemainingBitsInField = 0;
-
   placeFieldAtOffset(FieldOffset);
 
   if (!IsOverlappingEmptyField)
@@ -3064,14 +3049,10 @@ void MicrosoftRecordLayoutBuilder::layoutBitField(const FieldDecl *FD) {
   } else {
     // Allocate a new block of memory and place the bitfield in it.
     CharUnits FieldOffset = Size.alignTo(Info.Alignment);
-    uint64_t UnpaddedFieldOffsetInBits =
-        Context.toBits(DataSize) - RemainingBitsInField;
     placeFieldAtOffset(FieldOffset);
     Size = FieldOffset + Info.Size;
     Alignment = std::max(Alignment, Info.Alignment);
     RemainingBitsInField = Context.toBits(Info.Size) - Width;
-    ::CheckFieldPadding(Context, IsUnion, Context.toBits(FieldOffset),
-                        UnpaddedFieldOffsetInBits, FD);
   }
   DataSize = Size;
 }
@@ -3095,14 +3076,9 @@ MicrosoftRecordLayoutBuilder::layoutZeroWidthBitField(const FieldDecl *FD) {
   } else {
     // Round up the current record size to the field's alignment boundary.
     CharUnits FieldOffset = Size.alignTo(Info.Alignment);
-    uint64_t UnpaddedFieldOffsetInBits =
-        Context.toBits(DataSize) - RemainingBitsInField;
     placeFieldAtOffset(FieldOffset);
-    RemainingBitsInField = 0;
     Size = FieldOffset;
     Alignment = std::max(Alignment, Info.Alignment);
-    ::CheckFieldPadding(Context, IsUnion, Context.toBits(FieldOffset),
-                        UnpaddedFieldOffsetInBits, FD);
   }
   DataSize = Size;
 }
@@ -3227,9 +3203,6 @@ void MicrosoftRecordLayoutBuilder::layoutVirtualBases(const CXXRecordDecl *RD) {
 }
 
 void MicrosoftRecordLayoutBuilder::finalizeLayout(const RecordDecl *RD) {
-  uint64_t UnpaddedSizeInBits = Context.toBits(DataSize);
-  UnpaddedSizeInBits -= RemainingBitsInField;
-
   // Respect required alignment.  Note that in 32-bit mode Required alignment
   // may be 0 and cause size not to be updated.
   DataSize = Size;
@@ -3258,22 +3231,6 @@ void MicrosoftRecordLayoutBuilder::finalizeLayout(const RecordDecl *RD) {
     Size = Context.toCharUnitsFromBits(External.Size);
     if (External.Align)
       Alignment = Context.toCharUnitsFromBits(External.Align);
-    return;
-  }
-  unsigned CharBitNum = Context.getTargetInfo().getCharWidth();
-  uint64_t SizeInBits = Context.toBits(Size);
-  if (SizeInBits > UnpaddedSizeInBits) {
-    unsigned int PadSize = SizeInBits - UnpaddedSizeInBits;
-    bool InBits = true;
-    if (PadSize % CharBitNum == 0) {
-      PadSize = PadSize / CharBitNum;
-      InBits = false;
-    }
-
-    Context.getDiagnostics().Report(RD->getLocation(),
-                                    diag::warn_padded_struct_size)
-        << Context.getTypeDeclType(RD) << PadSize
-        << (InBits ? 1 : 0); // (byte|bit)
   }
 }