Revert "[LLVM][Clang][AArch64] Implement AArch64 build attributes (llvm#118771)"

This reverts commit d7fb4a2.

Buildbots failing:
https://lab.llvm.org/buildbot/#/builders/169/builds/7671
https://lab.llvm.org/buildbot/#/builders/65/builds/11046

Author: kazutakahirata

llvm/include/llvm/BinaryFormat/ELF.h

@@ -1158,8 +1158,6 @@ enum : unsigned {
   SHT_ARM_ATTRIBUTES = 0x70000003U,
   SHT_ARM_DEBUGOVERLAY = 0x70000004U,
   SHT_ARM_OVERLAYSECTION = 0x70000005U,
-  // Support for AArch64 build attributes
-  SHT_AARCH64_ATTRIBUTES = 0x70000003U,
   // Special aarch64-specific section for MTE support, as described in:
   // https://github.com/ARM-software/abi-aa/blob/main/pauthabielf64/pauthabielf64.rst#section-types
   SHT_AARCH64_AUTH_RELR = 0x70000004U,

llvm/include/llvm/MC/MCELFStreamer.h

@@ -96,7 +96,7 @@ class MCELFStreamer : public MCObjectStreamer {
     // This structure holds all attributes, accounting for their string /
     // numeric value, so we can later emit them in declaration order, keeping
     // all in the same vector.
-    enum Types {
+    enum {
       HiddenAttribute = 0,
       NumericAttribute,
       TextAttribute,
@@ -105,17 +105,6 @@ class MCELFStreamer : public MCObjectStreamer {
     unsigned Tag;
     unsigned IntValue;
     std::string StringValue;
-    AttributeItem(Types Ty, unsigned Tg, unsigned IV, std::string SV)
-        : Type(Ty), Tag(Tg), IntValue(IV), StringValue(SV) {}
-  };
-
-  /// ELF object attributes subsection support
-  struct AttributeSubSection {
-    bool IsActive;
-    StringRef VendorName;
-    unsigned IsOptional;
-    unsigned ParameterType;
-    SmallVector<AttributeItem, 64> Content;
   };
 
   // Attributes that are added and managed entirely by target.
@@ -130,23 +119,13 @@ class MCELFStreamer : public MCObjectStreamer {
                              unsigned Type, MCSection *&AttributeSection) {
     createAttributesSection(Vendor, Section, Type, AttributeSection, Contents);
   }
-  void
-  emitAttributesSection(MCSection *&AttributeSection, const Twine &Section,
-                        unsigned Type,
-                        SmallVector<AttributeSubSection, 64> &SubSectionVec) {
-    createAttributesWithSubsection(AttributeSection, Section, Type,
-                                   SubSectionVec);
-  }
 
 private:
   AttributeItem *getAttributeItem(unsigned Attribute);
-  size_t calculateContentSize(SmallVector<AttributeItem, 64> &AttrsVec) const;
+  size_t calculateContentSize(SmallVector<AttributeItem, 64> &AttrsVec);
   void createAttributesSection(StringRef Vendor, const Twine &Section,
                                unsigned Type, MCSection *&AttributeSection,
                                SmallVector<AttributeItem, 64> &AttrsVec);
-  void createAttributesWithSubsection(
-      MCSection *&AttributeSection, const Twine &Section, unsigned Type,
-      SmallVector<AttributeSubSection, 64> &SubSectionVec);
 
   // GNU attributes that will get emitted at the end of the asm file.
   SmallVector<AttributeItem, 64> GNUAttributes;

llvm/include/llvm/Support/AArch64BuildAttributes.h

@@ -696,8 +696,8 @@ MCELFStreamer::getAttributeItem(unsigned Attribute) {
   return nullptr;
 }
 
-size_t MCELFStreamer::calculateContentSize(
-    SmallVector<AttributeItem, 64> &AttrsVec) const {
+size_t
+MCELFStreamer::calculateContentSize(SmallVector<AttributeItem, 64> &AttrsVec) {
   size_t Result = 0;
   for (const AttributeItem &Item : AttrsVec) {
     switch (Item.Type) {
@@ -783,67 +783,6 @@ void MCELFStreamer::createAttributesSection(
   AttrsVec.clear();
 }
 
-void MCELFStreamer::createAttributesWithSubsection(
-    MCSection *&AttributeSection, const Twine &Section, unsigned Type,
-    SmallVector<AttributeSubSection, 64> &SubSectionVec) {
-  // <format-version: 'A'>
-  // [ <uint32: subsection-length> NTBS: vendor-name
-  //   <bytes: vendor-data>
-  // ]*
-  // vendor-data expends to:
-  // <uint8: optional> <uint8: parameter type> <attribute>*
-  if (0 == SubSectionVec.size()) {
-    return;
-  }
-
-  // Switch section to AttributeSection or get/create the section.
-  if (AttributeSection) {
-    switchSection(AttributeSection);
-  } else {
-    AttributeSection = getContext().getELFSection(Section, Type, 0);
-    switchSection(AttributeSection);
-
-    // Format version
-    emitInt8(0x41);
-  }
-
-  for (AttributeSubSection &SubSection : SubSectionVec) {
-    // subsection-length + vendor-name + '\0'
-    const size_t VendorHeaderSize = 4 + SubSection.VendorName.size() + 1;
-    // optional + parameter-type
-    const size_t VendorParameters = 1 + 1;
-    const size_t ContentsSize = calculateContentSize(SubSection.Content);
-
-    emitInt32(VendorHeaderSize + VendorParameters + ContentsSize);
-    emitBytes(SubSection.VendorName);
-    emitInt8(0); // '\0'
-    emitInt8(SubSection.IsOptional);
-    emitInt8(SubSection.ParameterType);
-
-    for (AttributeItem &Item : SubSection.Content) {
-      emitULEB128IntValue(Item.Tag);
-      switch (Item.Type) {
-      default:
-        assert(0 && "Invalid attribute type");
-        break;
-      case AttributeItem::NumericAttribute:
-        emitULEB128IntValue(Item.IntValue);
-        break;
-      case AttributeItem::TextAttribute:
-        emitBytes(Item.StringValue);
-        emitInt8(0); // '\0'
-        break;
-      case AttributeItem::NumericAndTextAttributes:
-        emitULEB128IntValue(Item.IntValue);
-        emitBytes(Item.StringValue);
-        emitInt8(0); // '\0'
-        break;
-      }
-    }
-  }
-  SubSectionVec.clear();
-}
-
 MCStreamer *llvm::createELFStreamer(MCContext &Context,
                                     std::unique_ptr<MCAsmBackend> &&MAB,
                                     std::unique_ptr<MCObjectWriter> &&OW,

llvm/lib/MC/MCELFStreamer.cpp

@@ -144,7 +144,6 @@ add_llvm_component_library(LLVMSupport
   APInt.cpp
   APSInt.cpp
   ARMBuildAttrs.cpp
-  AArch64BuildAttributes.cpp
   ARMAttributeParser.cpp
   ARMWinEH.cpp
   Allocator.cpp