3 files changed, 32 insertions, 9 deletions
diff --git a/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp b/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp
index ed2b3eb3aad..7e2ebdc46b3 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp
@@ -256,9 +256,16 @@ void MachOReader::readFunctionStartsData(Object &O) const {
 
 void MachOReader::readIndirectSymbolTable(Object &O) const {
   MachO::dysymtab_command DySymTab = MachOObj.getDysymtabLoadCommand();
-  for (uint32_t i = 0; i < DySymTab.nindirectsyms; ++i)
-    O.IndirectSymTable.Symbols.push_back(
-        MachOObj.getIndirectSymbolTableEntry(DySymTab, i));
+  constexpr uint32_t AbsOrLocalMask =
+      MachO::INDIRECT_SYMBOL_LOCAL | MachO::INDIRECT_SYMBOL_ABS;
+  for (uint32_t i = 0; i < DySymTab.nindirectsyms; ++i) {
+    uint32_t Index = MachOObj.getIndirectSymbolTableEntry(DySymTab, i);
+    if ((Index & AbsOrLocalMask) != 0)
+      O.IndirectSymTable.Symbols.emplace_back(Index, None);
+    else
+      O.IndirectSymTable.Symbols.emplace_back(
+          Index, O.SymTable.getSymbolByIndex(Index));
+  }
 }
 
 std::unique_ptr<Object> MachOReader::create() const {
diff --git a/llvm/tools/llvm-objcopy/MachO/MachOWriter.cpp b/llvm/tools/llvm-objcopy/MachO/MachOWriter.cpp
index 4ec91cc9eb7..59d57f7f2db 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOWriter.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOWriter.cpp
@@ -369,11 +369,14 @@ void MachOWriter::writeIndirectSymbolTable() {
       O.LoadCommands[*O.DySymTabCommandIndex]
           .MachOLoadCommand.dysymtab_command_data;
 
-  char *Out = (char *)B.getBufferStart() + DySymTabCommand.indirectsymoff;
-  assert((DySymTabCommand.nindirectsyms == O.IndirectSymTable.Symbols.size()) &&
-         "Incorrect indirect symbol table size");
-  memcpy(Out, O.IndirectSymTable.Symbols.data(),
-         sizeof(uint32_t) * O.IndirectSymTable.Symbols.size());
+  uint32_t *Out =
+      (uint32_t *)(B.getBufferStart() + DySymTabCommand.indirectsymoff);
+  for (const IndirectSymbolEntry &Sym : O.IndirectSymTable.Symbols) {
+    uint32_t Entry = (Sym.Symbol) ? (*Sym.Symbol)->Index : Sym.OriginalIndex;
+    if (IsLittleEndian != sys::IsLittleEndianHost)
+      sys::swapByteOrder(Entry);
+    *Out++ = Entry;
+  }
 }
 
 void MachOWriter::writeDataInCodeData() {
diff --git a/llvm/tools/llvm-objcopy/MachO/Object.h b/llvm/tools/llvm-objcopy/MachO/Object.h
index 36b0f7eb96d..bf802531a4f 100644
--- a/llvm/tools/llvm-objcopy/MachO/Object.h
+++ b/llvm/tools/llvm-objcopy/MachO/Object.h
@@ -112,8 +112,21 @@ struct SymbolTable {
   const SymbolEntry *getSymbolByIndex(uint32_t Index) const;
 };
 
+struct IndirectSymbolEntry {
+  // The original value in an indirect symbol table. Higher bits encode extra
+  // information (INDIRECT_SYMBOL_LOCAL and INDIRECT_SYMBOL_ABS).
+  uint32_t OriginalIndex;
+  /// The Symbol referenced by this entry. It's None if the index is
+  /// INDIRECT_SYMBOL_LOCAL or INDIRECT_SYMBOL_ABS.
+  Optional<const SymbolEntry *> Symbol;
+
+  IndirectSymbolEntry(uint32_t OriginalIndex,
+                      Optional<const SymbolEntry *> Symbol)
+      : OriginalIndex(OriginalIndex), Symbol(Symbol) {}
+};
+
 struct IndirectSymbolTable {
-  std::vector<uint32_t> Symbols;
+  std::vector<IndirectSymbolEntry> Symbols;
 };
 
 /// The location of the string table inside the binary is described by LC_SYMTAB