Always sort by offset first. NFC.

Every target changing sortRelocs was first calling the parent
implementation. Just run that first.

llvm-svn: 255898

1 files changed, 16 insertions, 0 deletions

diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp
index df7a606..a92b049 100644
--- a/llvm/lib/MC/ELFObjectWriter.cpp
+++ b/llvm/lib/MC/ELFObjectWriter.cpp
@@ -1046,10 +1046,26 @@ void ELFObjectWriter::WriteSecHdrEntry(uint32_t Name, uint32_t Type,
   WriteWord(EntrySize); // sh_entsize
 }
 
+// ELF doesn't require relocations to be in any order. We sort by the Offset,
+// just to match gnu as for easier comparison. The use type is an arbitrary way
+// of making the sort deterministic.
+static int cmpRel(const ELFRelocationEntry *AP, const ELFRelocationEntry *BP) {
+  const ELFRelocationEntry &A = *AP;
+  const ELFRelocationEntry &B = *BP;
+  if (A.Offset != B.Offset)
+    return B.Offset - A.Offset;
+  if (B.Type != A.Type)
+    return A.Type - B.Type;
+  llvm_unreachable("ELFRelocs might be unstable!");
+  return 0;
+}
+
 void ELFObjectWriter::writeRelocations(const MCAssembler &Asm,
                                        const MCSectionELF &Sec) {
   std::vector<ELFRelocationEntry> &Relocs = Relocations[&Sec];
 
+  array_pod_sort(Relocs.begin(), Relocs.end(), cmpRel);
+
   // Sort the relocation entries. Most targets just sort by Offset, but some
   // (e.g., MIPS) have additional constraints.
   TargetObjectWriter->sortRelocs(Asm, Relocs);