From 16f8142b11598d6d4a4c26333bd3cb9b9f4898f0 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Wed, 11 Nov 2020 10:20:30 -0800
Subject: [PATCH] [llvm-objcopy][ELF] Try fixing non-determinism of
 Segment::firstSection

---
 llvm/tools/llvm-objcopy/ELF/Object.cpp | 1 +
 llvm/tools/llvm-objcopy/ELF/Object.h   | 7 ++++---
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/llvm/tools/llvm-objcopy/ELF/Object.cpp b/llvm/tools/llvm-objcopy/ELF/Object.cpp
index 76db901e4abf..2f455d7ecc1e 100644
--- a/llvm/tools/llvm-objcopy/ELF/Object.cpp
+++ b/llvm/tools/llvm-objcopy/ELF/Object.cpp
@@ -1775,6 +1775,7 @@ template <class ELFT> Error ELFBuilder<ELFT>::readSectionHeaders() {
     Sec->Align = Shdr.sh_addralign;
     Sec->EntrySize = Shdr.sh_entsize;
     Sec->Index = Index++;
+    Sec->OriginalIndex = Sec->Index;
     Sec->OriginalData =
         ArrayRef<uint8_t>(ElfFile.base() + Shdr.sh_offset,
                           (Shdr.sh_type == SHT_NOBITS) ? 0 : Shdr.sh_size);
diff --git a/llvm/tools/llvm-objcopy/ELF/Object.h b/llvm/tools/llvm-objcopy/ELF/Object.h
index 81851813a3e7..5bd15890e5fe 100644
--- a/llvm/tools/llvm-objcopy/ELF/Object.h
+++ b/llvm/tools/llvm-objcopy/ELF/Object.h
@@ -390,8 +390,8 @@ public:
   Segment *ParentSegment = nullptr;
   uint64_t HeaderOffset = 0;
   uint32_t Index = 0;
-  bool HasSymbol = false;
 
+  uint32_t OriginalIndex = 0;
   uint64_t OriginalFlags = 0;
   uint64_t OriginalType = ELF::SHT_NULL;
   uint64_t OriginalOffset = std::numeric_limits<uint64_t>::max();
@@ -407,6 +407,7 @@ public:
   uint64_t Size = 0;
   uint64_t Type = ELF::SHT_NULL;
   ArrayRef<uint8_t> OriginalData;
+  bool HasSymbol = false;
 
   SectionBase() = default;
   SectionBase(const SectionBase &) = default;
@@ -435,9 +436,9 @@ private:
     bool operator()(const SectionBase *Lhs, const SectionBase *Rhs) const {
       // Some sections might have the same address if one of them is empty. To
       // fix this we can use the lexicographic ordering on ->Addr and the
-      // address of the actully stored section.
+      // original index.
       if (Lhs->OriginalOffset == Rhs->OriginalOffset)
-        return Lhs < Rhs;
+        return Lhs->OriginalIndex < Rhs->OriginalIndex;
       return Lhs->OriginalOffset < Rhs->OriginalOffset;
     }
   };