1 files changed, 24 insertions, 1 deletions
diff --git a/llvm/lib/MC/MCMachOStreamer.cpp b/llvm/lib/MC/MCMachOStreamer.cpp
index 4b74c569531..69995fa11d2 100644
--- a/llvm/lib/MC/MCMachOStreamer.cpp
+++ b/llvm/lib/MC/MCMachOStreamer.cpp
@@ -459,7 +459,30 @@ void MCMachOStreamer::FinishImpl() {
 
   // We have to set the fragment atom associations so we can relax properly for
   // Mach-O.
-  addFragmentAtoms();
+
+  // First, scan the symbol table to build a lookup table from fragments to
+  // defining symbols.
+  DenseMap<const MCFragment *, const MCSymbol *> DefiningSymbolMap;
+  for (const MCSymbol &Symbol : getAssembler().symbols()) {
+    if (getAssembler().isSymbolLinkerVisible(Symbol) && Symbol.isInSection() &&
+        !Symbol.isVariable()) {
+      // An atom defining symbol should never be internal to a fragment.
+      assert(Symbol.getOffset() == 0 &&
+             "Invalid offset in atom defining symbol!");
+      DefiningSymbolMap[Symbol.getFragment()] = &Symbol;
+    }
+  }
+
+  // Set the fragment atom associations by tracking the last seen atom defining
+  // symbol.
+  for (MCSection &Sec : getAssembler()) {
+    const MCSymbol *CurrentAtom = nullptr;
+    for (MCFragment &Frag : Sec) {
+      if (const MCSymbol *Symbol = DefiningSymbolMap.lookup(&Frag))
+        CurrentAtom = Symbol;
+      Frag.setAtom(CurrentAtom);
+    }
+  }
 
   this->MCObjectStreamer::FinishImpl();
 }