1 files changed, 120 insertions, 0 deletions
diff --git a/lld/lib/ReaderWriter/ELF/ARM/ARMELFWriters.h b/lld/lib/ReaderWriter/ELF/ARM/ARMELFWriters.h
new file mode 100644
index 00000000000..a842ebe5303
--- /dev/null
+++ b/lld/lib/ReaderWriter/ELF/ARM/ARMELFWriters.h
@@ -0,0 +1,120 @@
+//===- lib/ReaderWriter/ELF/ARM/ARMELFWriters.h ---------------------------===//
+//
+//                             The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLD_READER_WRITER_ELF_ARM_ARM_ELF_WRITERS_H
+#define LLD_READER_WRITER_ELF_ARM_ARM_ELF_WRITERS_H
+
+#include "ARMLinkingContext.h"
+#include "ARMSymbolTable.h"
+#include "llvm/Support/ELF.h"
+
+namespace lld {
+namespace elf {
+
+template <class WriterT> class ARMELFWriter : public WriterT {
+public:
+  ARMELFWriter(ARMLinkingContext &ctx, TargetLayout<ELF32LE> &layout);
+
+  void finalizeDefaultAtomValues() override;
+
+  /// \brief Create symbol table.
+  unique_bump_ptr<SymbolTable<ELF32LE>> createSymbolTable() override;
+
+  // Setup the ELF header.
+  std::error_code setELFHeader() override;
+
+protected:
+  static const char *gotSymbol;
+  static const char *dynamicSymbol;
+
+private:
+  ARMLinkingContext &_ctx;
+  TargetLayout<ELF32LE> &_armLayout;
+};
+
+template <class WriterT>
+const char *ARMELFWriter<WriterT>::gotSymbol = "_GLOBAL_OFFSET_TABLE_";
+template <class WriterT>
+const char *ARMELFWriter<WriterT>::dynamicSymbol = "_DYNAMIC";
+
+template <class WriterT>
+ARMELFWriter<WriterT>::ARMELFWriter(ARMLinkingContext &ctx,
+                                    TargetLayout<ELF32LE> &layout)
+    : WriterT(ctx, layout), _ctx(ctx), _armLayout(layout) {}
+
+template <class WriterT>
+void ARMELFWriter<WriterT>::finalizeDefaultAtomValues() {
+  // Finalize the atom values that are part of the parent.
+  WriterT::finalizeDefaultAtomValues();
+
+  if (auto *gotAtom = _armLayout.findAbsoluteAtom(gotSymbol)) {
+    if (auto gotpltSection = _armLayout.findOutputSection(".got.plt"))
+      gotAtom->_virtualAddr = gotpltSection->virtualAddr();
+    else if (auto gotSection = _armLayout.findOutputSection(".got"))
+      gotAtom->_virtualAddr = gotSection->virtualAddr();
+    else
+      gotAtom->_virtualAddr = 0;
+  }
+
+  if (auto *dynamicAtom = _armLayout.findAbsoluteAtom(dynamicSymbol)) {
+    if (auto dynamicSection = _armLayout.findOutputSection(".dynamic"))
+      dynamicAtom->_virtualAddr = dynamicSection->virtualAddr();
+    else
+      dynamicAtom->_virtualAddr = 0;
+  }
+
+  // Set required by gcc libc __ehdr_start symbol with pointer to ELF header
+  if (auto ehdr = _armLayout.findAbsoluteAtom("__ehdr_start"))
+    ehdr->_virtualAddr = this->_elfHeader->virtualAddr();
+
+  // Set required by gcc libc symbols __exidx_start/__exidx_end
+  this->updateScopeAtomValues("exidx", ".ARM.exidx");
+}
+
+template <class WriterT>
+unique_bump_ptr<SymbolTable<ELF32LE>>
+ARMELFWriter<WriterT>::createSymbolTable() {
+  return unique_bump_ptr<SymbolTable<ELF32LE>>(new (this->_alloc)
+                                                   ARMSymbolTable(_ctx));
+}
+
+template <class WriterT> std::error_code ARMELFWriter<WriterT>::setELFHeader() {
+  if (std::error_code ec = WriterT::setELFHeader())
+    return ec;
+
+  // Set ARM-specific flags.
+  this->_elfHeader->e_flags(llvm::ELF::EF_ARM_EABI_VER5 |
+                            llvm::ELF::EF_ARM_VFP_FLOAT);
+
+  StringRef entryName = _ctx.entrySymbolName();
+  if (const AtomLayout *al = _armLayout.findAtomLayoutByName(entryName)) {
+    if (const auto *ea = dyn_cast<DefinedAtom>(al->_atom)) {
+      switch (ea->codeModel()) {
+      case DefinedAtom::codeNA:
+        if (al->_virtualAddr & 0x3) {
+          llvm::report_fatal_error(
+              "Two least bits must be zero for ARM entry point");
+        }
+        break;
+      case DefinedAtom::codeARMThumb:
+        // Fixup entry point for Thumb code.
+        this->_elfHeader->e_entry(al->_virtualAddr | 0x1);
+        break;
+      default:
+        llvm_unreachable("Wrong code model of entry point atom");
+      }
+    }
+  }
+
+  return std::error_code();
+}
+
+} // namespace elf
+} // namespace lld
+
+#endif // LLD_READER_WRITER_ELF_ARM_ARM_ELF_WRITERS_H