diff --git a/lld/MachO/UnwindInfoSection.h b/lld/MachO/UnwindInfoSection.h
--- a/lld/MachO/UnwindInfoSection.h
+++ b/lld/MachO/UnwindInfoSection.h
@@ -40,6 +40,7 @@
 protected:
   UnwindInfoSection();
   virtual void prepareRelocations(ConcatInputSection *) = 0;
+  virtual void resolvePersonalitySymbols() = 0;
 
   ConcatOutputSection *compactUnwindSection;
   uint64_t unwindInfoSize = 0;
diff --git a/lld/MachO/UnwindInfoSection.cpp b/lld/MachO/UnwindInfoSection.cpp
--- a/lld/MachO/UnwindInfoSection.cpp
+++ b/lld/MachO/UnwindInfoSection.cpp
@@ -107,6 +107,7 @@
 class UnwindInfoSectionImpl final : public UnwindInfoSection {
 public:
   void prepareRelocations(ConcatInputSection *) override;
+  void resolvePersonalitySymbols() override;
   void addInput(ConcatInputSection *) override;
   void finalize() override;
   void writeTo(uint8_t *buf) const override;
@@ -126,6 +127,13 @@
   std::vector<CompactUnwindEntry<Ptr> *> cuPtrVector;
   std::vector<SecondLevelPage> secondLevelPages;
   uint64_t level2PagesOffset = 0;
+
+  // Collections of personality symbols bucketed into different symbol kinds.
+  SmallDenseSet<Defined *> localSyms;
+  SmallDenseSet<DylibSymbol *> dylibSyms;
+  // Mapping of a local personality symbol to their corresponding dylib symbol.
+  // (ie., (local symbol's GOT index + 1) -> (dylib symbol's GOT index + 1))
+  DenseMap<Ptr, Ptr> oldToNew;
 };
 
 UnwindInfoSection::UnwindInfoSection()
@@ -138,8 +146,40 @@
 void UnwindInfoSection::prepareRelocations() {
   for (ConcatInputSection *isec : compactUnwindSection->inputs)
     prepareRelocations(isec);
+
+  resolvePersonalitySymbols();
 }
 
+// If symbol is a local Defined (ie 't'), then replace it with
+// a Dylib symbol with the same name.
+// We do this because sometimes personality symbols are intentionally
+// defined as a local symbol as hack to get around another bug. As
+// a result, often we see two of the same personality symbols but different
+// type, causing "too many personalities to encode".
+// See https://reviews.llvm.org/D107533 for full discussions.
+template <class Ptr>
+void UnwindInfoSectionImpl<Ptr>::resolvePersonalitySymbols() {
+  for (Defined *lSym : localSyms) {
+    Symbol *found = nullptr;
+    for (DylibSymbol *dSym : dylibSyms) {
+      if (lSym->getName() == dSym->getName()) {
+        found = dSym;
+        break;
+      }
+    }
+
+    // If there isn't a dylib personality with the same name,
+    // then treat the local symbol as usual.
+    // Otherwise, we recorded a mapping of their personalities
+    // to be used later in encoding.
+    if (found == nullptr) {
+      personalityTable[{lSym->isec, lSym->value}] = lSym;
+      in.got->addEntry(lSym);
+    } else {
+      oldToNew[lSym->gotIndex + 1] = found->gotIndex + 1;
+    }
+  }
+}
 template <class Ptr>
 void UnwindInfoSectionImpl<Ptr>::addInput(ConcatInputSection *isec) {
   assert(isec->getSegName() == segment_names::ld &&
@@ -195,14 +235,20 @@
         Symbol *&personality =
             personalityTable[{defined->isec, defined->value}];
         if (personality == nullptr) {
-          personality = defined;
-          in.got->addEntry(defined);
+          if (!defined->isExternal())
+            // If this symbol is a local, we may need special treatment later.
+            localSyms.insert(defined);
+          else {
+            personality = defined;
+            in.got->addEntry(defined);
+          }
         } else if (personality != defined) {
           r.referent = personality;
         }
         continue;
       }
       assert(isa<DylibSymbol>(s));
+      dylibSyms.insert(dyn_cast<DylibSymbol>(s));
       in.got->addEntry(s);
       continue;
     }
@@ -442,7 +488,15 @@
     foldBegin = foldEnd;
   }
   cuPtrVector.erase(foldWrite, cuPtrVector.end());
-
+  // Update the personality to the right values before encoding.
+  if (!oldToNew.empty()) {
+    for (CompactUnwindEntry<Ptr> *&entry : cuPtrVector) {
+      auto it = oldToNew.find(entry->personality);
+      if (it != oldToNew.end()) {
+        entry->personality = it->second;
+      }
+    }
+  }
   encodePersonalities(cuPtrVector, personalities);
 
   // Count frequencies of the folded encodings
diff --git a/lld/test/MachO/compact-unwind-both-local-and-dylib-personality.s b/lld/test/MachO/compact-unwind-both-local-and-dylib-personality.s
new file mode 100644
--- /dev/null
+++ b/lld/test/MachO/compact-unwind-both-local-and-dylib-personality.s
@@ -0,0 +1,240 @@
+## Tests that lld-macho can handle the case where personality symbols with the same name
+## are both from a dylib and locally defined in an object file.
+
+# REQUIRES: x86
+# RUN: rm -rf %t; split-file %s %t
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin19.0.0 %t/user_2.s -o %t/user_2.o
+# RUN: yaml2obj %t/combined.yaml > %t/combined.o
+
+## Pre-condition: check that ___gxx_personality_v0 really is locally defined in combined.o before we proceed.
+# RUN: llvm-nm %t/combined.o | grep '___gxx_personality_v0'  | FileCheck %s --check-prefix=PRECHECK
+# PRECHECK: {{.*}} t ___gxx_personality_v0
+# PRECHECK-NOT: {{.*}} U ___gxx_personality_v0
+# PRECHECK-NOT: {{.*}} T ___gxx_personality_v0
+
+## check that we can link with 4 personalities without crashing:
+## ___gxx_personality_v0 (from libc++.tbd) ___gxx_personality_v0(local), _personality_1 and _personality_2
+# RUN: %lld -pie -lSystem -lc++ %t/user_2.o -o %t/user_2.out
+# RUN: %lld -pie  -lSystem -lc++  %t/user_2.o %t/combined.o -o %t/a.out
+
+## postlink check: FIXME: maybe need a better verification here.
+# RUN: llvm-nm %t/a.out | FileCheck %s --check-prefix=POSTCHECK
+# POSTCHECK: {{.*}} U ___gxx_personality_v0
+# POSTCHECK: {{.*}} t ___gxx_personality_v0	
+	
+#--- user_2.s
+.globl _main, _personality_1, _personality_2
+
+.text
+
+_bar:
+  .cfi_startproc
+  .cfi_personality 155, _personality_1
+  .cfi_def_cfa_offset 16
+  retq
+  .cfi_endproc
+
+_baz:
+  .cfi_startproc
+  .cfi_personality 155, _personality_2
+  .cfi_def_cfa_offset 16
+  retq
+  .cfi_endproc
+
+_main:
+  .cfi_startproc
+  .cfi_personality 155, ___gxx_personality_v0
+  .cfi_def_cfa_offset 16
+  retq
+  .cfi_endproc
+
+_personality_1:
+  retq
+_personality_2:
+  retq
+  
+## This yaml was created from the combined.o object file described in this comment:
+## https://reviews.llvm.org/D107533#2935217
+#--- combined.yaml
+--- !mach-o
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