diff --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
--- a/lld/MachO/Driver.cpp
+++ b/lld/MachO/Driver.cpp
@@ -267,8 +267,9 @@
     // We don't take a reference to cachedFile here because the
     // loadArchiveMember() call below may recursively call addFile() and
     // invalidate this reference.
-    if (ArchiveFile *cachedFile = loadedArchives[path])
-      return cachedFile;
+    auto entry = loadedArchives.find(path);
+    if (entry != loadedArchives.end())
+      return entry->second;
 
     std::unique_ptr<object::Archive> archive = CHECK(
         object::Archive::create(mbref), path + ": failed to parse archive");
diff --git a/lld/MachO/InputSection.h b/lld/MachO/InputSection.h
--- a/lld/MachO/InputSection.h
+++ b/lld/MachO/InputSection.h
@@ -21,6 +21,8 @@
 #include "llvm/ADT/TinyPtrVector.h"
 #include "llvm/BinaryFormat/MachO.h"
 
+#include <list>
+
 namespace lld {
 namespace macho {
 
@@ -62,7 +64,7 @@
   bool isFinal = false;
 
   ArrayRef<uint8_t> data;
-  std::vector<Reloc> relocs;
+  std::list<Reloc> relocs;
   // The symbols that belong to this InputSection, sorted by value. With
   // .subsections_via_symbols, there is typically only one element here.
   llvm::TinyPtrVector<Defined *> symbols;
diff --git a/lld/MachO/InputSection.cpp b/lld/MachO/InputSection.cpp
--- a/lld/MachO/InputSection.cpp
+++ b/lld/MachO/InputSection.cpp
@@ -139,13 +139,14 @@
 
   memcpy(buf, data.data(), data.size());
 
-  for (size_t i = 0; i < relocs.size(); i++) {
-    const Reloc &r = relocs[i];
+  for (auto it = relocs.begin(); it != relocs.end(); ++it) {
+    const Reloc &r = *it;
     uint8_t *loc = buf + r.offset;
     uint64_t referentVA = 0;
     if (target->hasAttr(r.type, RelocAttrBits::SUBTRAHEND)) {
       const Symbol *fromSym = r.referent.get<Symbol *>();
-      const Reloc &minuend = relocs[++i];
+      ++it;
+      const Reloc &minuend = *it;
       uint64_t minuendVA;
       if (const Symbol *toSym = minuend.referent.dyn_cast<Symbol *>())
         minuendVA = toSym->getVA() + minuend.addend;
diff --git a/lld/MachO/UnwindInfoSection.cpp b/lld/MachO/UnwindInfoSection.cpp
--- a/lld/MachO/UnwindInfoSection.cpp
+++ b/lld/MachO/UnwindInfoSection.cpp
@@ -198,8 +198,7 @@
   // work. But since there are usually just few personality functions
   // that are referenced from many places, at least some of them likely
   // live, it wouldn't reduce number of got entries.
-  for (size_t i = 0; i < isec->relocs.size(); ++i) {
-    Reloc &r = isec->relocs[i];
+  for (Reloc &r : isec->relocs) {
     assert(target->hasAttr(r.type, RelocAttrBits::UNSIGNED));
 
     // Functions and LSDA entries always reside in the same object file as the