[PATCH] D78786: [llvm-objcopy] Delete dead code after D71035. NFC

[Fangrui Song via Phabricator via llvm-commits]

MaskRay created this revision.
MaskRay added reviewers: grimar, jhenderson.
Herald added subscribers: llvm-commits, abrachet, emaste.
Herald added a reviewer: espindola.
Herald added a reviewer: alexshap.
Herald added a reviewer: rupprecht.
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MaskRay edited the summary of this revision.

Spotted by https://reviews.llvm.org/D74755#1998673

> it looks like OrderedSegments in the function is only used to set the physical address to the virtual address when there are no physical addresses set amongst these sections.

I believe this behavior was copied from https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=6ffd79000b45e77b3625143932ffbf781b6aecab (2008-05)
The commit was made for very old linkers.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D78786

Files:
  llvm/tools/llvm-objcopy/ELF/Object.cpp


Index: llvm/tools/llvm-objcopy/ELF/Object.cpp
===================================================================
--- llvm/tools/llvm-objcopy/ELF/Object.cpp
+++ llvm/tools/llvm-objcopy/ELF/Object.cpp
@@ -1101,14 +1101,6 @@
   return A->Index < B->Index;
 }
 
-static bool compareSegmentsByPAddr(const Segment *A, const Segment *B) {
-  if (A->PAddr < B->PAddr)
-    return true;
-  if (A->PAddr > B->PAddr)
-    return false;
-  return A->Index < B->Index;
-}
-
 void BasicELFBuilder::initFileHeader() {
   Obj->Flags = 0x0;
   Obj->Type = ET_REL;
@@ -2228,30 +2220,20 @@
   // so that we know that anytime ->ParentSegment is set that segment has
   // already had it's offset properly set. We only want to consider the segments
   // that will affect layout of allocated sections so we only add those.
-  std::vector<Segment *> OrderedSegments;
+  std::vector<Segment *> Segments;
   for (const SectionBase &Sec : Obj.allocSections())
     if (Sec.ParentSegment != nullptr)
-      OrderedSegments.push_back(Sec.ParentSegment);
+      Segments.push_back(Sec.ParentSegment);
 
   // For binary output, we're going to use physical addresses instead of
   // virtual addresses, since a binary output is used for cases like ROM
   // loading and physical addresses are intended for ROM loading.
   // However, if no segment has a physical address, we'll fallback to using
   // virtual addresses for all.
-  if (all_of(OrderedSegments,
-             [](const Segment *Seg) { return Seg->PAddr == 0; }))
-    for (Segment *Seg : OrderedSegments)
+  if (all_of(Segments, [](const Segment *Seg) { return Seg->PAddr == 0; }))
+    for (Segment *Seg : Segments)
       Seg->PAddr = Seg->VAddr;
 
-  llvm::stable_sort(OrderedSegments, compareSegmentsByPAddr);
-
-  // Because we add a ParentSegment for each section we might have duplicate
-  // segments in OrderedSegments. If there were duplicates then layoutSegments
-  // would do very strange things.
-  auto End =
-      std::unique(std::begin(OrderedSegments), std::end(OrderedSegments));
-  OrderedSegments.erase(End, std::end(OrderedSegments));
-
   // Compute the section LMA based on its sh_offset and the containing segment's
   // p_offset and p_paddr. Also compute the minimum LMA of all sections as
   // MinAddr. In the output, the contents between address 0 and MinAddr will be


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