[MC] Export llvm::ELFObjectWriter

Similar to commit 28fcafb50274be2520117eacb0a886adafefe59d (2011) for
MachObjectWriter and commit 9539a7796094ff5fb59d9c685140ea2e214b945c for
WinCOFFObjectWriter.

MCELFStreamer can now access ELFObjectWriter directly without adding
ELF-specific markGnuAbi (https://reviews.llvm.org/D97976) and
setOverrideABIVersion to MCObjectWriter.

A few member variables have to be made public since we cannot use a
friend declaration for ELFWriter.

1 files changed, 13 insertions, 64 deletions

diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp
index 59d796b..21f481d 100644
--- a/llvm/lib/MC/ELFObjectWriter.cpp
+++ b/llvm/lib/MC/ELFObjectWriter.cpp
@@ -67,7 +67,6 @@ using namespace llvm;
 
 namespace {
 
-class ELFObjectWriter;
 struct ELFWriter;
 
 bool isDwoSection(const MCSectionELF &Sec) {
@@ -200,64 +199,6 @@ public:
                     const MCSectionELF &Section);
 };
 
-class ELFObjectWriter : public MCObjectWriter {
-  /// The target specific ELF writer instance.
-  std::unique_ptr<MCELFObjectTargetWriter> TargetObjectWriter;
-
-  DenseMap<const MCSectionELF *, std::vector<ELFRelocationEntry>> Relocations;
-
-  DenseMap<const MCSymbolELF *, const MCSymbolELF *> Renames;
-
-  bool SeenGnuAbi = false;
-
-  std::optional<uint8_t> OverrideABIVersion;
-
-  bool hasRelocationAddend() const;
-
-  bool shouldRelocateWithSymbol(const MCAssembler &Asm, const MCValue &Val,
-                                const MCSymbolELF *Sym, uint64_t C,
-                                unsigned Type) const;
-
-public:
-  ELFObjectWriter(std::unique_ptr<MCELFObjectTargetWriter> MOTW)
-      : TargetObjectWriter(std::move(MOTW)) {}
-
-  void reset() override {
-    SeenGnuAbi = false;
-    OverrideABIVersion.reset();
-    Relocations.clear();
-    Renames.clear();
-    MCObjectWriter::reset();
-  }
-
-  bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
-                                              const MCSymbol &SymA,
-                                              const MCFragment &FB, bool InSet,
-                                              bool IsPCRel) const override;
-
-  virtual bool checkRelocation(MCContext &Ctx, SMLoc Loc,
-                               const MCSectionELF *From,
-                               const MCSectionELF *To) {
-    return true;
-  }
-
-  void recordRelocation(MCAssembler &Asm, const MCFragment *Fragment,
-                        const MCFixup &Fixup, MCValue Target,
-                        uint64_t &FixedValue) override;
-  bool usesRela(const MCTargetOptions *TO, const MCSectionELF &Sec) const;
-
-  void executePostLayoutBinding(MCAssembler &Asm) override;
-
-  void markGnuAbi() override { SeenGnuAbi = true; }
-  bool seenGnuAbi() const { return SeenGnuAbi; }
-
-  bool seenOverrideABIVersion() const { return OverrideABIVersion.has_value(); }
-  uint8_t getOverrideABIVersion() const { return OverrideABIVersion.value(); }
-  void setOverrideABIVersion(uint8_t V) override { OverrideABIVersion = V; }
-
-  friend struct ELFWriter;
-};
-
 class ELFSingleObjectWriter : public ELFObjectWriter {
   raw_pwrite_stream &OS;
   bool IsLittleEndian;
@@ -403,8 +344,8 @@ void ELFWriter::writeHeader(const MCAssembler &Asm) {
                    ? int(ELF::ELFOSABI_GNU)
                    : OSABI);
   // e_ident[EI_ABIVERSION]
-  W.OS << char(OWriter.seenOverrideABIVersion()
-                   ? OWriter.getOverrideABIVersion()
+  W.OS << char(OWriter.OverrideABIVersion
+                   ? *OWriter.OverrideABIVersion
                    : OWriter.TargetObjectWriter->getABIVersion());
 
   W.OS.write_zeros(ELF::EI_NIDENT - ELF::EI_PAD);
@@ -779,7 +720,7 @@ void ELFWriter::computeSymbolTable(MCAssembler &Asm,
 }
 
 void ELFWriter::writeAddrsigSection() {
-  for (const MCSymbol *Sym : OWriter.AddrsigSyms)
+  for (const MCSymbol *Sym : OWriter.getAddrsigSyms())
     if (Sym->getIndex() != 0)
       encodeULEB128(Sym->getIndex(), W.OS);
 }
@@ -1150,7 +1091,7 @@ uint64_t ELFWriter::writeObject(MCAssembler &Asm) {
     StrTabBuilder.finalize();
   } else {
     MCSectionELF *AddrsigSection;
-    if (OWriter.EmitAddrsigSection) {
+    if (OWriter.getEmitAddrsigSection()) {
       AddrsigSection = Ctx.getELFSection(".llvm_addrsig", ELF::SHT_LLVM_ADDRSIG,
                                          ELF::SHF_EXCLUDE);
       addToSectionTable(AddrsigSection);
@@ -1170,7 +1111,7 @@ uint64_t ELFWriter::writeObject(MCAssembler &Asm) {
       RelSection->setOffsets(SecStart, SecEnd);
     }
 
-    if (OWriter.EmitAddrsigSection) {
+    if (OWriter.getEmitAddrsigSection()) {
       uint64_t SecStart = W.OS.tell();
       writeAddrsigSection();
       uint64_t SecEnd = W.OS.tell();
@@ -1215,6 +1156,14 @@ uint64_t ELFWriter::writeObject(MCAssembler &Asm) {
   return W.OS.tell() - StartOffset;
 }
 
+void ELFObjectWriter::reset() {
+  SeenGnuAbi = false;
+  OverrideABIVersion.reset();
+  Relocations.clear();
+  Renames.clear();
+  MCObjectWriter::reset();
+}
+
 bool ELFObjectWriter::hasRelocationAddend() const {
   return TargetObjectWriter->hasRelocationAddend();
 }