From 0377a22491ed19ba2d9a6fc0ed34c901a3f56faa Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Mon, 20 Jul 2015 21:45:56 +0000
Subject: [PATCH] Simplify now that we can iterate backwards. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242715 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Object/ELF.h        | 24 +++++-------------------
 tools/llvm-readobj/ELFDumper.cpp | 19 ++++++++++++++++---
 2 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/include/llvm/Object/ELF.h b/include/llvm/Object/ELF.h
index 82fc19bc626..eed9bdd69e9 100644
--- a/include/llvm/Object/ELF.h
+++ b/include/llvm/Object/ELF.h
@@ -282,11 +282,9 @@ public:
   }
 
   const Elf_Dyn *dynamic_table_begin() const;
-  /// \param NULLEnd use one past the first DT_NULL entry as the end instead of
-  /// the section size.
-  const Elf_Dyn *dynamic_table_end(bool NULLEnd = false) const;
-  Elf_Dyn_Range dynamic_table(bool NULLEnd = false) const {
-    return make_range(dynamic_table_begin(), dynamic_table_end(NULLEnd));
+  const Elf_Dyn *dynamic_table_end() const;
+  Elf_Dyn_Range dynamic_table() const {
+    return make_range(dynamic_table_begin(), dynamic_table_end());
   }
 
   const Elf_Sym *dynamic_symbol_begin() const {
@@ -818,24 +816,12 @@ ELFFile<ELFT>::dynamic_table_begin() const {
 
 template <class ELFT>
 const typename ELFFile<ELFT>::Elf_Dyn *
-ELFFile<ELFT>::dynamic_table_end(bool NULLEnd) const {
+ELFFile<ELFT>::dynamic_table_end() const {
   uint64_t Size = DynamicRegion.Size;
   if (Size % sizeof(Elf_Dyn))
     report_fatal_error("Invalid dynamic table size");
 
-  const Elf_Dyn *Ret = dynamic_table_begin() + Size / sizeof(Elf_Dyn);
-
-  if (NULLEnd) {
-    const Elf_Dyn *Start = dynamic_table_begin();
-    while (Start != Ret && Start->getTag() != ELF::DT_NULL)
-      ++Start;
-
-    // Include the DT_NULL.
-    if (Start != Ret)
-      ++Start;
-    Ret = Start;
-  }
-  return Ret;
+  return dynamic_table_begin() + Size / sizeof(Elf_Dyn);
 }
 
 template <class ELFT>
diff --git a/tools/llvm-readobj/ELFDumper.cpp b/tools/llvm-readobj/ELFDumper.cpp
index df85e7631f7..a03b6174a14 100644
--- a/tools/llvm-readobj/ELFDumper.cpp
+++ b/tools/llvm-readobj/ELFDumper.cpp
@@ -1052,9 +1052,20 @@ template <> void ELFDumper<ELFType<support::little, false>>::printUnwindInfo() {
 
 template<class ELFT>
 void ELFDumper<ELFT>::printDynamicTable() {
-  auto DynTable = Obj->dynamic_table(true);
+  auto I = Obj->dynamic_table_begin();
+  auto E = Obj->dynamic_table_end();
 
-  ptrdiff_t Total = std::distance(DynTable.begin(), DynTable.end());
+  if (I == E)
+    return;
+
+  --E;
+  while (I != E && E->getTag() == ELF::DT_NULL)
+    --E;
+  if (E->getTag() != ELF::DT_NULL)
+    ++E;
+  ++E;
+
+  ptrdiff_t Total = std::distance(I, E);
   if (Total == 0)
     return;
 
@@ -1066,7 +1077,9 @@ void ELFDumper<ELFT>::printDynamicTable() {
   W.startLine()
      << "  Tag" << (Is64 ? "                " : "        ") << "Type"
      << "                 " << "Name/Value\n";
-  for (const auto &Entry : DynTable) {
+  while (I != E) {
+    const typename ELFO::Elf_Dyn &Entry = *I;
+    ++I;
     W.startLine()
        << "  "
        << format(Is64 ? "0x%016" PRIX64 : "0x%08" PRIX64, Entry.getTag())
-- 
2.34.1