MCAssmembler: Move ELFHeaderEFlags to ELFObjectWriter

Now that MCELFStreamer can access ELFObjectWriter (commit
70c52b6), we can move ELFHeaderEFlags
there.

llvm/include/llvm/MC/MCAssembler.h

@@ -94,13 +94,6 @@ class MCAssembler {
   /// By default it's 0, which means bundling is disabled.
   unsigned BundleAlignSize = 0;
 
-  /// ELF specific e_header flags
-  // It would be good if there were an MCELFAssembler class to hold this.
-  // ELF header flags are used both by the integrated and standalone assemblers.
-  // Access to the flags is necessary in cases where assembler directives affect
-  // which flags to be set.
-  unsigned ELFHeaderEFlags = 0;
-
   /// Evaluate a fixup to a relocatable expression and the value which should be
   /// placed into the fixup.
   ///
@@ -200,10 +193,6 @@ class MCAssembler {
   /// Flag a function symbol as the target of a .thumb_func directive.
   void setIsThumbFunc(const MCSymbol *Func) { ThumbFuncs.insert(Func); }
 
-  /// ELF e_header flags
-  unsigned getELFHeaderEFlags() const { return ELFHeaderEFlags; }
-  void setELFHeaderEFlags(unsigned Flags) { ELFHeaderEFlags = Flags; }
-
   /// Reuse an assembler instance
   ///
   void reset();

llvm/include/llvm/MC/MCELFObjectWriter.h

@@ -154,6 +154,8 @@ class MCELFObjectTargetWriter : public MCObjectTargetWriter {
 };
 
 class ELFObjectWriter : public MCObjectWriter {
+  unsigned ELFHeaderEFlags = 0;
+
 public:
   std::unique_ptr<MCELFObjectTargetWriter> TargetObjectWriter;
   DenseMap<const MCSectionELF *, std::vector<ELFRelocationEntry>> Relocations;
@@ -187,6 +189,9 @@ class ELFObjectWriter : public MCObjectWriter {
     return true;
   }
 
+  unsigned getELFHeaderEFlags() const { return ELFHeaderEFlags; }
+  void setELFHeaderEFlags(unsigned Flags) { ELFHeaderEFlags = Flags; }
+
   // Mark that we have seen GNU ABI usage (e.g. SHF_GNU_RETAIN, STB_GNU_UNIQUE).
   void markGnuAbi() { SeenGnuAbi = true; }
   bool seenGnuAbi() const { return SeenGnuAbi; }

llvm/lib/MC/ELFObjectWriter.cpp

@@ -360,7 +360,7 @@ void ELFWriter::writeHeader(const MCAssembler &Asm) {
   WriteWord(0);                     // e_shoff = sec hdr table off in bytes
 
   // e_flags = whatever the target wants
-  W.write<uint32_t>(Asm.getELFHeaderEFlags());
+  W.write<uint32_t>(OWriter.getELFHeaderEFlags());
 
   // e_ehsize = ELF header size
   W.write<uint16_t>(is64Bit() ? sizeof(ELF::Elf64_Ehdr)
@@ -1157,6 +1157,7 @@ uint64_t ELFWriter::writeObject(MCAssembler &Asm) {
 }
 
 void ELFObjectWriter::reset() {
+  ELFHeaderEFlags = 0;
   SeenGnuAbi = false;
   OverrideABIVersion.reset();
   Relocations.clear();

llvm/lib/MC/MCAssembler.cpp

@@ -97,7 +97,6 @@ void MCAssembler::reset() {
   FileNames.clear();
   ThumbFuncs.clear();
   BundleAlignSize = 0;
-  ELFHeaderEFlags = 0;
 
   // reset objects owned by us
   if (getBackendPtr())

llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUTargetStreamer.cpp

@@ -605,9 +605,9 @@ MCELFStreamer &AMDGPUTargetELFStreamer::getStreamer() {
 // We use it for emitting the accumulated PAL metadata as a .note record.
 // The PAL metadata is reset after it is emitted.
 void AMDGPUTargetELFStreamer::finish() {
-  MCAssembler &MCA = getStreamer().getAssembler();
-  MCA.setELFHeaderEFlags(getEFlags());
-  getStreamer().getWriter().setOverrideABIVersion(
+  ELFObjectWriter &W = getStreamer().getWriter();
+  W.setELFHeaderEFlags(getEFlags());
+  W.setOverrideABIVersion(
       getELFABIVersion(STI.getTargetTriple(), CodeObjectVersion));
 
   std::string Blob;

llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp

@@ -1128,7 +1128,7 @@ void ARMELFStreamer::reset() {
   // MCELFStreamer clear's the assembler's e_flags. However, for
   // arm we manually set the ABI version on streamer creation, so
   // do the same here
-  getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
+  getWriter().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
 }
 
 inline void ARMELFStreamer::SwitchToEHSection(StringRef Prefix,
@@ -1484,7 +1484,7 @@ MCELFStreamer *createARMELFStreamer(MCContext &Context,
   // FIXME: This should eventually end up somewhere else where more
   // intelligent flag decisions can be made. For now we are just maintaining
   // the status quo for ARM and setting EF_ARM_EABI_VER5 as the default.
-  S->getAssembler().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
+  S->getWriter().setELFHeaderEFlags(ELF::EF_ARM_EABI_VER5);
 
   return S;
 }

llvm/lib/Target/AVR/MCTargetDesc/AVRELFStreamer.cpp

@@ -56,14 +56,13 @@ static unsigned getEFlagsForFeatureSet(const FeatureBitset &Features) {
 
 AVRELFStreamer::AVRELFStreamer(MCStreamer &S, const MCSubtargetInfo &STI)
     : AVRTargetStreamer(S) {
-
-  MCAssembler &MCA = getStreamer().getAssembler();
-  unsigned EFlags = MCA.getELFHeaderEFlags();
+  ELFObjectWriter &W = getStreamer().getWriter();
+  unsigned EFlags = W.getELFHeaderEFlags();
 
   EFlags |= getEFlagsForFeatureSet(STI.getFeatureBits());
   EFlags |= ELF::EF_AVR_LINKRELAX_PREPARED;
 
-  MCA.setELFHeaderEFlags(EFlags);
+  W.setELFHeaderEFlags(EFlags);
 }
 
 } // end namespace llvm

llvm/lib/Target/CSKY/MCTargetDesc/CSKYELFStreamer.cpp

@@ -31,10 +31,10 @@ using namespace llvm;
 CSKYTargetELFStreamer::CSKYTargetELFStreamer(MCStreamer &S,
                                              const MCSubtargetInfo &STI)
     : CSKYTargetStreamer(S), CurrentVendor("csky") {
-  MCAssembler &MCA = getStreamer().getAssembler();
+  ELFObjectWriter &W = getStreamer().getWriter();
   const FeatureBitset &Features = STI.getFeatureBits();
 
-  unsigned EFlags = MCA.getELFHeaderEFlags();
+  unsigned EFlags = W.getELFHeaderEFlags();
 
   EFlags |= ELF::EF_CSKY_ABIV2;
 
@@ -62,7 +62,7 @@ CSKYTargetELFStreamer::CSKYTargetELFStreamer(MCStreamer &S,
 
   EFlags |= ELF::EF_CSKY_EFV1;
 
-  MCA.setELFHeaderEFlags(EFlags);
+  W.setELFHeaderEFlags(EFlags);
 }
 
 MCELFStreamer &CSKYTargetELFStreamer::getStreamer() {

llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCTargetDesc.cpp

@@ -291,8 +291,7 @@ class HexagonTargetELFStreamer : public HexagonTargetStreamer {
   }
   HexagonTargetELFStreamer(MCStreamer &S, MCSubtargetInfo const &STI)
       : HexagonTargetStreamer(S) {
-    MCAssembler &MCA = getStreamer().getAssembler();
-    MCA.setELFHeaderEFlags(Hexagon_MC::GetELFFlags(STI));
+    getStreamer().getWriter().setELFHeaderEFlags(Hexagon_MC::GetELFFlags(STI));
   }
 
   void emitCommonSymbolSorted(MCSymbol *Symbol, uint64_t Size,

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchELFStreamer.cpp

@@ -37,7 +37,7 @@ MCELFStreamer &LoongArchTargetELFStreamer::getStreamer() {
 
 void LoongArchTargetELFStreamer::finish() {
   LoongArchTargetStreamer::finish();
-  MCAssembler &MCA = getStreamer().getAssembler();
+  ELFObjectWriter &W = getStreamer().getWriter();
   LoongArchABI::ABI ABI = getTargetABI();
 
   // Figure out the e_flags.
@@ -48,7 +48,7 @@ void LoongArchTargetELFStreamer::finish() {
   // based relocs from day one.
   //
   // Refer to LoongArch ELF psABI v2.01 for details.
-  unsigned EFlags = MCA.getELFHeaderEFlags();
+  unsigned EFlags = W.getELFHeaderEFlags();
   EFlags |= ELF::EF_LOONGARCH_OBJABI_V1;
   switch (ABI) {
   case LoongArchABI::ABI_ILP32S:
@@ -66,7 +66,7 @@ void LoongArchTargetELFStreamer::finish() {
   case LoongArchABI::ABI_Unknown:
     llvm_unreachable("Improperly initialized target ABI");
   }
-  MCA.setELFHeaderEFlags(EFlags);
+  W.setELFHeaderEFlags(EFlags);
 }
 
 namespace {

llvm/lib/Target/MSP430/MCTargetDesc/MSP430ELFStreamer.cpp

@@ -35,10 +35,6 @@ class MSP430TargetELFStreamer : public MCTargetStreamer {
 MSP430TargetELFStreamer::MSP430TargetELFStreamer(MCStreamer &S,
                                                  const MCSubtargetInfo &STI)
     : MCTargetStreamer(S) {
-  MCAssembler &MCA = getStreamer().getAssembler();
-  unsigned EFlags = MCA.getELFHeaderEFlags();
-  MCA.setELFHeaderEFlags(EFlags);
-
   // Emit build attributes section according to
   // MSP430 EABI (slaa534.pdf, part 13).
   MCSection *AttributeSection = getStreamer().getContext().getELFSection(

llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp

@@ -801,6 +801,7 @@ MipsTargetELFStreamer::MipsTargetELFStreamer(MCStreamer &S,
                                              const MCSubtargetInfo &STI)
     : MipsTargetStreamer(S), MicroMipsEnabled(false), STI(STI) {
   MCAssembler &MCA = getStreamer().getAssembler();
+  ELFObjectWriter &W = getStreamer().getWriter();
 
   // It's possible that MCObjectFileInfo isn't fully initialized at this point
   // due to an initialization order problem where LLVMTargetMachine creates the
@@ -824,7 +825,7 @@ MipsTargetELFStreamer::MipsTargetELFStreamer(MCStreamer &S,
   // We can fix this by making the target streamer construct
   // the ABI, but this is fraught with wide ranging dependency
   // issues as well.
-  unsigned EFlags = MCA.getELFHeaderEFlags();
+  unsigned EFlags = W.getELFHeaderEFlags();
 
   // FIXME: Fix a dependency issue by instantiating the ABI object to some
   // default based off the triple. The triple doesn't describe the target
@@ -873,7 +874,7 @@ MipsTargetELFStreamer::MipsTargetELFStreamer(MCStreamer &S,
   if (Features[Mips::FeatureNaN2008])
     EFlags |= ELF::EF_MIPS_NAN2008;
 
-  MCA.setELFHeaderEFlags(EFlags);
+  W.setELFHeaderEFlags(EFlags);
 }
 
 void MipsTargetELFStreamer::emitLabel(MCSymbol *S) {
@@ -889,6 +890,7 @@ void MipsTargetELFStreamer::emitLabel(MCSymbol *S) {
 
 void MipsTargetELFStreamer::finish() {
   MCAssembler &MCA = getStreamer().getAssembler();
+  ELFObjectWriter &W = getStreamer().getWriter();
   const MCObjectFileInfo &OFI = *MCA.getContext().getObjectFileInfo();
   MCELFStreamer &S = getStreamer();
 
@@ -925,7 +927,7 @@ void MipsTargetELFStreamer::finish() {
 
   // Update e_header flags. See the FIXME and comment above in
   // the constructor for a full rundown on this.
-  unsigned EFlags = MCA.getELFHeaderEFlags();
+  unsigned EFlags = W.getELFHeaderEFlags();
 
   // ABI
   // N64 does not require any ABI bits.
@@ -948,7 +950,7 @@ void MipsTargetELFStreamer::finish() {
   if (Pic)
     EFlags |= ELF::EF_MIPS_PIC | ELF::EF_MIPS_CPIC;
 
-  MCA.setELFHeaderEFlags(EFlags);
+  W.setELFHeaderEFlags(EFlags);
 
   // Emit all the option records.
   // At the moment we are only emitting .Mips.options (ODK_REGINFO) and
@@ -988,25 +990,25 @@ void MipsTargetELFStreamer::emitDirectiveSetNoMicroMips() {
 }
 
 void MipsTargetELFStreamer::setUsesMicroMips() {
-  MCAssembler &MCA = getStreamer().getAssembler();
-  unsigned Flags = MCA.getELFHeaderEFlags();
+  ELFObjectWriter &W = getStreamer().getWriter();
+  unsigned Flags = W.getELFHeaderEFlags();
   Flags |= ELF::EF_MIPS_MICROMIPS;
-  MCA.setELFHeaderEFlags(Flags);
+  W.setELFHeaderEFlags(Flags);
 }
 
 void MipsTargetELFStreamer::emitDirectiveSetMips16() {
-  MCAssembler &MCA = getStreamer().getAssembler();
-  unsigned Flags = MCA.getELFHeaderEFlags();
+  ELFObjectWriter &W = getStreamer().getWriter();
+  unsigned Flags = W.getELFHeaderEFlags();
   Flags |= ELF::EF_MIPS_ARCH_ASE_M16;
-  MCA.setELFHeaderEFlags(Flags);
+  W.setELFHeaderEFlags(Flags);
   forbidModuleDirective();
 }
 
 void MipsTargetELFStreamer::emitDirectiveSetNoReorder() {
-  MCAssembler &MCA = getStreamer().getAssembler();
-  unsigned Flags = MCA.getELFHeaderEFlags();
+  ELFObjectWriter &W = getStreamer().getWriter();
+  unsigned Flags = W.getELFHeaderEFlags();
   Flags |= ELF::EF_MIPS_NOREORDER;
-  MCA.setELFHeaderEFlags(Flags);
+  W.setELFHeaderEFlags(Flags);
   forbidModuleDirective();
 }
 
@@ -1063,45 +1065,45 @@ void MipsTargetELFStreamer::emitDirectiveEnt(const MCSymbol &Symbol) {
 }
 
 void MipsTargetELFStreamer::emitDirectiveAbiCalls() {
-  MCAssembler &MCA = getStreamer().getAssembler();
-  unsigned Flags = MCA.getELFHeaderEFlags();
+  ELFObjectWriter &W = getStreamer().getWriter();
+  unsigned Flags = W.getELFHeaderEFlags();
   Flags |= ELF::EF_MIPS_CPIC | ELF::EF_MIPS_PIC;
-  MCA.setELFHeaderEFlags(Flags);
+  W.setELFHeaderEFlags(Flags);
 }
 
 void MipsTargetELFStreamer::emitDirectiveNaN2008() {
-  MCAssembler &MCA = getStreamer().getAssembler();
-  unsigned Flags = MCA.getELFHeaderEFlags();
+  ELFObjectWriter &W = getStreamer().getWriter();
+  unsigned Flags = W.getELFHeaderEFlags();
   Flags |= ELF::EF_MIPS_NAN2008;
-  MCA.setELFHeaderEFlags(Flags);
+  W.setELFHeaderEFlags(Flags);
 }
 
 void MipsTargetELFStreamer::emitDirectiveNaNLegacy() {
-  MCAssembler &MCA = getStreamer().getAssembler();
-  unsigned Flags = MCA.getELFHeaderEFlags();
+  ELFObjectWriter &W = getStreamer().getWriter();
+  unsigned Flags = W.getELFHeaderEFlags();
   Flags &= ~ELF::EF_MIPS_NAN2008;
-  MCA.setELFHeaderEFlags(Flags);
+  W.setELFHeaderEFlags(Flags);
 }
 
 void MipsTargetELFStreamer::emitDirectiveOptionPic0() {
-  MCAssembler &MCA = getStreamer().getAssembler();
-  unsigned Flags = MCA.getELFHeaderEFlags();
+  ELFObjectWriter &W = getStreamer().getWriter();
+  unsigned Flags = W.getELFHeaderEFlags();
   // This option overrides other PIC options like -KPIC.
   Pic = false;
   Flags &= ~ELF::EF_MIPS_PIC;
-  MCA.setELFHeaderEFlags(Flags);
+  W.setELFHeaderEFlags(Flags);
 }
 
 void MipsTargetELFStreamer::emitDirectiveOptionPic2() {
-  MCAssembler &MCA = getStreamer().getAssembler();
-  unsigned Flags = MCA.getELFHeaderEFlags();
+  ELFObjectWriter &W = getStreamer().getWriter();
+  unsigned Flags = W.getELFHeaderEFlags();
   Pic = true;
   // NOTE: We are following the GAS behaviour here which means the directive
   // 'pic2' also sets the CPIC bit in the ELF header. This is different from
   // what is stated in the SYSV ABI which consider the bits EF_MIPS_PIC and
   // EF_MIPS_CPIC to be mutually exclusive.
   Flags |= ELF::EF_MIPS_PIC | ELF::EF_MIPS_CPIC;
-  MCA.setELFHeaderEFlags(Flags);
+  W.setELFHeaderEFlags(Flags);
 }
 
 void MipsTargetELFStreamer::emitDirectiveInsn() {

llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.cpp

@@ -298,15 +298,14 @@ class PPCTargetELFStreamer : public PPCTargetStreamer {
   }
 
   void emitAbiVersion(int AbiVersion) override {
-    MCAssembler &MCA = getStreamer().getAssembler();
-    unsigned Flags = MCA.getELFHeaderEFlags();
+    ELFObjectWriter &W = getStreamer().getWriter();
+    unsigned Flags = W.getELFHeaderEFlags();
     Flags &= ~ELF::EF_PPC64_ABI;
     Flags |= (AbiVersion & ELF::EF_PPC64_ABI);
-    MCA.setELFHeaderEFlags(Flags);
+    W.setELFHeaderEFlags(Flags);
   }
 
   void emitLocalEntry(MCSymbolELF *S, const MCExpr *LocalOffset) override {
-    MCAssembler &MCA = getStreamer().getAssembler();
 
     // encodePPC64LocalEntryOffset will report an error if it cannot
     // encode LocalOffset.
@@ -319,9 +318,10 @@ class PPCTargetELFStreamer : public PPCTargetStreamer {
 
     // For GAS compatibility, unless we already saw a .abiversion directive,
     // set e_flags to indicate ELFv2 ABI.
-    unsigned Flags = MCA.getELFHeaderEFlags();
+    ELFObjectWriter &W = getStreamer().getWriter();
+    unsigned Flags = W.getELFHeaderEFlags();
     if ((Flags & ELF::EF_PPC64_ABI) == 0)
-      MCA.setELFHeaderEFlags(Flags | 2);
+      W.setELFHeaderEFlags(Flags | 2);
   }
 
   void emitAssignment(MCSymbol *S, const MCExpr *Value) override {

llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFStreamer.cpp

@@ -87,10 +87,10 @@ void RISCVTargetELFStreamer::finishAttributeSection() {
 
 void RISCVTargetELFStreamer::finish() {
   RISCVTargetStreamer::finish();
-  MCAssembler &MCA = getStreamer().getAssembler();
+  ELFObjectWriter &W = getStreamer().getWriter();
   RISCVABI::ABI ABI = getTargetABI();
 
-  unsigned EFlags = MCA.getELFHeaderEFlags();
+  unsigned EFlags = W.getELFHeaderEFlags();
 
   if (hasRVC())
     EFlags |= ELF::EF_RISCV_RVC;
@@ -117,7 +117,7 @@ void RISCVTargetELFStreamer::finish() {
     llvm_unreachable("Improperly initialised target ABI");
   }
 
-  MCA.setELFHeaderEFlags(EFlags);
+  W.setELFHeaderEFlags(EFlags);
 }
 
 void RISCVTargetELFStreamer::reset() {