macho-reloc-extern.patch

diff --git a/llvm/test/tools/llvm-objcopy/MachO/copy-relocations.test b/llvm/test/tools/llvm-objcopy/MachO/copy-relocations.test
new file mode 100644
index 00000000000..8bfac24ee93
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/MachO/copy-relocations.test
@@ -0,0 +1,111 @@
+## Show that llvm-objcopy copies relocation entries where r_extern=0.
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-objcopy %t %t2
+# RUN: cmp %t %t2
+
+--- !mach-o
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+      - sectname:        __text
+        segname:         __TEXT
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+      - sectname:        __eh_frame
+        segname:         __TEXT
+        addr:            0x0000000000000038
+        size:            64
+        offset:          0x00000210
+        align:           3
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+    nsyms:           1
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+  - cmd:             LC_DYSYMTAB
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+    - ''
+    - _main
+    - ''
+...
diff --git a/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp b/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp
index cf8c93b1cea..db2eabf1eda 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp
@@ -103,6 +103,7 @@ extractSections(const object::MachOObjectFile::LoadCommandInfo &LoadCmd,
       R.Symbol = nullptr; // We'll fill this field later.
       R.Info = MachOObj.getRelocation(RI->getRawDataRefImpl());
       R.Scattered = MachOObj.isRelocationScattered(R.Info);
+      R.Extern = R.Scattered ? false : MachOObj.getPlainRelocationExternal(R.Info);
       S.Relocations.push_back(R);
     }
 
@@ -208,7 +209,7 @@ void MachOReader::setSymbolInRelocationInfo(Object &O) const {
   for (auto &LC : O.LoadCommands)
     for (auto &Sec : LC.Sections)
       for (auto &Reloc : Sec.Relocations)
-        if (!Reloc.Scattered) {
+        if (!Reloc.Scattered && Reloc.Extern) {
           auto *Info = reinterpret_cast<MachO::relocation_info *>(&Reloc.Info);
           Reloc.Symbol = O.SymTable.getSymbolByIndex(Info->r_symbolnum);
         }
diff --git a/llvm/tools/llvm-objcopy/MachO/MachOWriter.cpp b/llvm/tools/llvm-objcopy/MachO/MachOWriter.cpp
index 0d9590612ec..5e91cb798aa 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOWriter.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOWriter.cpp
@@ -240,7 +240,7 @@ void MachOWriter::writeSections() {
              Sec.Content.size());
       for (size_t Index = 0; Index < Sec.Relocations.size(); ++Index) {
         auto RelocInfo = Sec.Relocations[Index];
-        if (!RelocInfo.Scattered) {
+        if (!RelocInfo.Scattered && RelocInfo.Extern) {
           auto *Info =
               reinterpret_cast<MachO::relocation_info *>(&RelocInfo.Info);
           Info->r_symbolnum = RelocInfo.Symbol->Index;
diff --git a/llvm/tools/llvm-objcopy/MachO/Object.h b/llvm/tools/llvm-objcopy/MachO/Object.h
index 1ce488126b3..4b8fd38169e 100644
--- a/llvm/tools/llvm-objcopy/MachO/Object.h
+++ b/llvm/tools/llvm-objcopy/MachO/Object.h
@@ -148,6 +148,8 @@ struct RelocationInfo {
   const SymbolEntry *Symbol;
   // True if Info is a scattered_relocation_info.
   bool Scattered;
+  // True if the r_symbolnum points to a section number (i.e. r_extern=0).
+  bool Extern;
   MachO::any_relocation_info Info;
 };