1 files changed, 109 insertions, 0 deletions
diff --git a/contrib/llvm/tools/lld/ELF/DWARF.cpp b/contrib/llvm/tools/lld/ELF/DWARF.cpp
new file mode 100644
index 000000000000..17e1a4d600eb
--- /dev/null
+++ b/contrib/llvm/tools/lld/ELF/DWARF.cpp
@@ -0,0 +1,109 @@
+//===- DWARF.cpp ----------------------------------------------------------===//
+//
+//                             The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// The -gdb-index option instructs the linker to emit a .gdb_index section.
+// The section contains information to make gdb startup faster.
+// The format of the section is described at
+// https://sourceware.org/gdb/onlinedocs/gdb/Index-Section-Format.html.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DWARF.h"
+#include "Symbols.h"
+#include "Target.h"
+#include "lld/Common/Memory.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugPubTable.h"
+#include "llvm/Object/ELFObjectFile.h"
+
+using namespace llvm;
+using namespace llvm::object;
+using namespace lld;
+using namespace lld::elf;
+
+template <class ELFT> LLDDwarfObj<ELFT>::LLDDwarfObj(ObjFile<ELFT> *Obj) {
+  for (InputSectionBase *Sec : Obj->getSections()) {
+    if (!Sec)
+      continue;
+
+    if (LLDDWARFSection *M =
+            StringSwitch<LLDDWARFSection *>(Sec->Name)
+                .Case(".debug_addr", &AddrSection)
+                .Case(".debug_gnu_pubnames", &GnuPubNamesSection)
+                .Case(".debug_gnu_pubtypes", &GnuPubTypesSection)
+                .Case(".debug_info", &InfoSection)
+                .Case(".debug_ranges", &RangeSection)
+                .Case(".debug_rnglists", &RngListsSection)
+                .Case(".debug_line", &LineSection)
+                .Default(nullptr)) {
+      M->Data = toStringRef(Sec->data());
+      M->Sec = Sec;
+      continue;
+    }
+
+    if (Sec->Name == ".debug_abbrev")
+      AbbrevSection = toStringRef(Sec->data());
+    else if (Sec->Name == ".debug_str")
+      StrSection = toStringRef(Sec->data());
+    else if (Sec->Name == ".debug_line_str")
+      LineStringSection = toStringRef(Sec->data());
+  }
+}
+
+// Find if there is a relocation at Pos in Sec.  The code is a bit
+// more complicated than usual because we need to pass a section index
+// to llvm since it has no idea about InputSection.
+template <class ELFT>
+template <class RelTy>
+Optional<RelocAddrEntry>
+LLDDwarfObj<ELFT>::findAux(const InputSectionBase &Sec, uint64_t Pos,
+                           ArrayRef<RelTy> Rels) const {
+  auto It = std::lower_bound(
+      Rels.begin(), Rels.end(), Pos,
+      [](const RelTy &A, uint64_t B) { return A.r_offset < B; });
+  if (It == Rels.end() || It->r_offset != Pos)
+    return None;
+  const RelTy &Rel = *It;
+
+  const ObjFile<ELFT> *File = Sec.getFile<ELFT>();
+  uint32_t SymIndex = Rel.getSymbol(Config->IsMips64EL);
+  const typename ELFT::Sym &Sym = File->getELFSyms()[SymIndex];
+  uint32_t SecIndex = File->getSectionIndex(Sym);
+
+  // Broken debug info can point to a non-Defined symbol.
+  auto *DR = dyn_cast<Defined>(&File->getRelocTargetSym(Rel));
+  if (!DR) {
+    RelType Type = Rel.getType(Config->IsMips64EL);
+    if (Type != Target->NoneRel)
+      error(toString(File) + ": relocation " + lld::toString(Type) + " at 0x" +
+            llvm::utohexstr(Rel.r_offset) + " has unsupported target");
+    return None;
+  }
+  uint64_t Val = DR->Value + getAddend<ELFT>(Rel);
+
+  // FIXME: We should be consistent about always adding the file
+  // offset or not.
+  if (DR->Section->Flags & ELF::SHF_ALLOC)
+    Val += cast<InputSection>(DR->Section)->getOffsetInFile();
+
+  return RelocAddrEntry{SecIndex, Val};
+}
+
+template <class ELFT>
+Optional<RelocAddrEntry> LLDDwarfObj<ELFT>::find(const llvm::DWARFSection &S,
+                                                 uint64_t Pos) const {
+  auto &Sec = static_cast<const LLDDWARFSection &>(S);
+  if (Sec.Sec->AreRelocsRela)
+    return findAux(*Sec.Sec, Pos, Sec.Sec->template relas<ELFT>());
+  return findAux(*Sec.Sec, Pos, Sec.Sec->template rels<ELFT>());
+}
+
+template class elf::LLDDwarfObj<ELF32LE>;
+template class elf::LLDDwarfObj<ELF32BE>;
+template class elf::LLDDwarfObj<ELF64LE>;
+template class elf::LLDDwarfObj<ELF64BE>;