diff --git a/lld/MachO/CMakeLists.txt b/lld/MachO/CMakeLists.txt
--- a/lld/MachO/CMakeLists.txt
+++ b/lld/MachO/CMakeLists.txt
@@ -5,6 +5,7 @@
 add_lld_library(lldMachO2
   Arch/X86_64.cpp
   Driver.cpp
+  ExportTrie.cpp
   InputFiles.cpp
   InputSection.cpp
   OutputSegment.cpp
diff --git a/lld/MachO/ExportTrie.h b/lld/MachO/ExportTrie.h
new file mode 100644
--- /dev/null
+++ b/lld/MachO/ExportTrie.h
@@ -0,0 +1,41 @@
+//===- ExportTrie.h ---------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLD_MACHO_EXPORT_TRIE_H
+#define LLD_MACHO_EXPORT_TRIE_H
+
+#include "llvm/ADT/ArrayRef.h"
+
+#include <vector>
+
+namespace lld {
+namespace macho {
+
+struct TrieNode;
+class Symbol;
+
+class TrieBuilder {
+public:
+  void addSymbol(const Symbol &sym) { exported.push_back(&sym); }
+  // Returns the size in bytes of the serialized trie.
+  size_t build();
+  void writeTo(uint8_t *buf);
+
+private:
+  TrieNode *makeNode();
+  void sortAndBuild(llvm::MutableArrayRef<const Symbol *> vec, TrieNode *node,
+                    size_t lastPos, size_t pos);
+
+  std::vector<const Symbol *> exported;
+  std::vector<TrieNode *> nodes;
+};
+
+} // namespace macho
+} // namespace lld
+
+#endif
diff --git a/lld/MachO/ExportTrie.cpp b/lld/MachO/ExportTrie.cpp
new file mode 100644
--- /dev/null
+++ b/lld/MachO/ExportTrie.cpp
@@ -0,0 +1,236 @@
+//===- ExportTrie.cpp -----------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This is a partial implementation of the Mach-O export trie format. It's
+// essentially a symbol table encoded as a compressed prefix trie, meaning that
+// the common prefixes of each symbol name are shared for a more compact
+// representation. The prefixes are stored on the edges of the trie, and one
+// edge can represent multiple characters. For example, given two exported
+// symbols _bar and _baz, we will have a trie like this (terminal nodes are
+// marked with an asterisk):
+//
+//              +-+-+
+//              |   | // root node
+//              +-+-+
+//                |
+//                | _ba
+//                |
+//              +-+-+
+//              |   |
+//              +-+-+
+//           r /     \ z
+//            /       \
+//        +-+-+       +-+-+
+//        | * |       | * |
+//        +-+-+       +-+-+
+//
+// More documentation of the format can be found in
+// llvm/tools/obj2yaml/macho2yaml.cpp.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ExportTrie.h"
+#include "Symbols.h"
+
+#include "lld/Common/Memory.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/BinaryFormat/MachO.h"
+#include "llvm/Support/LEB128.h"
+
+using namespace llvm;
+using namespace llvm::MachO;
+using namespace lld;
+using namespace lld::macho;
+
+namespace {
+
+struct Edge {
+  Edge(StringRef s, TrieNode *node) : substring(s), child(node) {}
+
+  StringRef substring;
+  struct TrieNode *child;
+};
+
+struct ExportInfo {
+  uint64_t address;
+  // TODO: Add proper support for re-exports & stub-and-resolver flags.
+};
+
+} // namespace
+
+namespace lld {
+namespace macho {
+
+struct TrieNode {
+  std::vector<Edge> edges;
+  Optional<ExportInfo> info;
+  // Estimated offset from the start of the serialized trie to the current node.
+  // This will converge to the true offset when updateOffset() is run to a
+  // fixpoint.
+  size_t offset = 0;
+
+  // Returns whether the new estimated offset differs from the old one.
+  bool updateOffset(size_t &nextOffset);
+  void writeTo(uint8_t *buf);
+};
+
+bool TrieNode::updateOffset(size_t &nextOffset) {
+  // Size of the whole node (including the terminalSize and the outgoing edges.)
+  // In contrast, terminalSize only records the size of the other data in the
+  // node.
+  size_t nodeSize;
+  if (info) {
+    uint64_t flags = 0;
+    uint32_t terminalSize =
+        getULEB128Size(flags) + getULEB128Size(info->address);
+    // Overall node size so far is the uleb128 size of the length of the symbol
+    // info + the symbol info itself.
+    nodeSize = terminalSize + getULEB128Size(terminalSize);
+  } else {
+    nodeSize = 1; // Size of terminalSize (which has a value of 0)
+  }
+  // Compute size of all child edges.
+  ++nodeSize; // Byte for number of children.
+  for (Edge &edge : edges) {
+    nodeSize += edge.substring.size() + 1             // String length.
+                + getULEB128Size(edge.child->offset); // Offset len.
+  }
+  // On input, 'nextOffset' is the new preferred location for this node.
+  bool result = (offset != nextOffset);
+  // Store new location in node object for use by parents.
+  offset = nextOffset;
+  nextOffset += nodeSize;
+  return result;
+}
+
+void TrieNode::writeTo(uint8_t *buf) {
+  buf += offset;
+  if (info) {
+    // TrieNodes with Symbol info: size, flags address
+    uint64_t flags = 0; // TODO: emit proper flags
+    uint32_t terminalSize =
+        getULEB128Size(flags) + getULEB128Size(info->address);
+    buf += encodeULEB128(terminalSize, buf);
+    buf += encodeULEB128(flags, buf);
+    buf += encodeULEB128(info->address, buf);
+  } else {
+    // TrieNode with no Symbol info.
+    *buf++ = 0; // terminalSize
+  }
+  // Add number of children. TODO: Handle case where we have more than 256.
+  assert(edges.size() < 256);
+  *buf++ = edges.size();
+  // Append each child edge substring and node offset.
+  for (const Edge &edge : edges) {
+    memcpy(buf, edge.substring.data(), edge.substring.size());
+    buf += edge.substring.size();
+    *buf++ = '\0';
+    buf += encodeULEB128(edge.child->offset, buf);
+  }
+}
+
+TrieNode *TrieBuilder::makeNode() {
+  auto *node = make<TrieNode>();
+  nodes.emplace_back(node);
+  return node;
+}
+
+static int charAt(const Symbol *sym, size_t pos) {
+  StringRef str = sym->getName();
+  if (pos >= str.size())
+    return -1;
+  return str[pos];
+}
+
+// Build the trie by performing a three-way radix quicksort: We start by sorting
+// the strings by their first characters, then sort the strings with the same
+// first characters by their second characters, and so on recursively. Each
+// time the prefixes diverge, we add a node to the trie.
+//
+// node:    The most recently created node along this path in the trie (i.e.
+//          the furthest from the root.)
+// lastPos: The prefix length of the most recently created node, i.e. the number
+//          of characters along its path from the root.
+// pos:     The string index we are currently sorting on. Note that each symbol
+//          S contained in vec has the same prefix S[0...pos).
+void TrieBuilder::sortAndBuild(MutableArrayRef<const Symbol *> vec,
+                               TrieNode *node, size_t lastPos, size_t pos) {
+tailcall:
+  if (vec.empty())
+    return;
+
+  // Partition items so that items in [0, i) are less than the pivot,
+  // [i, j) are the same as the pivot, and [j, vec.size()) are greater than
+  // the pivot.
+  const Symbol *pivotSymbol = vec[vec.size() / 2];
+  int pivot = charAt(pivotSymbol, pos);
+  size_t i = 0;
+  size_t j = vec.size();
+  for (size_t k = 0; k < j;) {
+    int c = charAt(vec[k], pos);
+    if (c < pivot)
+      std::swap(vec[i++], vec[k++]);
+    else if (c > pivot)
+      std::swap(vec[--j], vec[k]);
+    else
+      k++;
+  }
+
+  bool isTerminal = pivot == -1;
+  bool prefixesDiverge = i != 0 || j != vec.size();
+  if (lastPos != pos && (isTerminal || prefixesDiverge)) {
+    TrieNode *newNode = makeNode();
+    node->edges.emplace_back(pivotSymbol->getName().slice(lastPos, pos),
+                             newNode);
+    node = newNode;
+    lastPos = pos;
+  }
+
+  sortAndBuild(vec.slice(0, i), node, lastPos, pos);
+  sortAndBuild(vec.slice(j), node, lastPos, pos);
+
+  if (isTerminal) {
+    assert(j - i == 1); // no duplicate symbols
+    node->info = {pivotSymbol->getVA() + ImageBase};
+  } else {
+    // This is the tail-call-optimized version of the following:
+    // sortAndBuild(vec.slice(i, j - i), node, lastPos, pos + 1);
+    vec = vec.slice(i, j - i);
+    ++pos;
+    goto tailcall;
+  }
+}
+
+size_t TrieBuilder::build() {
+  if (exported.empty())
+    return 0;
+
+  TrieNode *root = makeNode();
+  sortAndBuild(exported, root, 0, 0);
+
+  // Assign each node in the vector an offset in the trie stream, iterating
+  // until all uleb128 sizes have stabilized.
+  size_t offset;
+  bool more;
+  do {
+    offset = 0;
+    more = false;
+    for (TrieNode *node : nodes)
+      more |= node->updateOffset(offset);
+  } while (more);
+
+  return offset;
+}
+
+void TrieBuilder::writeTo(uint8_t *buf) {
+  for (TrieNode *node : nodes)
+    node->writeTo(buf);
+}
+
+} // namespace macho
+} // namespace lld
diff --git a/lld/MachO/SyntheticSections.h b/lld/MachO/SyntheticSections.h
--- a/lld/MachO/SyntheticSections.h
+++ b/lld/MachO/SyntheticSections.h
@@ -9,6 +9,7 @@
 #ifndef LLD_MACHO_SYNTHETIC_SECTIONS_H
 #define LLD_MACHO_SYNTHETIC_SECTIONS_H
 
+#include "ExportTrie.h"
 #include "InputSection.h"
 #include "Target.h"
 #include "llvm/ADT/SetVector.h"
@@ -101,14 +102,16 @@
 public:
   ExportSection();
   void finalizeContents();
-  size_t getSize() const override { return contents.size(); }
+  size_t getSize() const override { return size; }
   // Like other sections in __LINKEDIT, the export section is special: its
   // offsets are recorded in the LC_DYLD_INFO_ONLY load command, instead of in
   // section headers.
   bool isHidden() const override { return true; }
   void writeTo(uint8_t *buf) override;
 
-  SmallVector<char, 128> contents;
+private:
+  TrieBuilder trieBuilder;
+  size_t size = 0;
 };
 
 // Stores the strings referenced by the symbol table.
diff --git a/lld/MachO/SyntheticSections.cpp b/lld/MachO/SyntheticSections.cpp
--- a/lld/MachO/SyntheticSections.cpp
+++ b/lld/MachO/SyntheticSections.cpp
@@ -8,6 +8,7 @@
 
 #include "SyntheticSections.h"
 #include "Config.h"
+#include "ExportTrie.h"
 #include "InputFiles.h"
 #include "OutputSegment.h"
 #include "SymbolTable.h"
@@ -136,38 +137,14 @@
 }
 
 void ExportSection::finalizeContents() {
-  raw_svector_ostream os{contents};
-  std::vector<const Defined *> exported;
   // TODO: We should check symbol visibility.
   for (const Symbol *sym : symtab->getSymbols())
     if (auto *defined = dyn_cast<Defined>(sym))
-      exported.push_back(defined);
-
-  if (exported.empty())
-    return;
-
-  if (exported.size() > 1) {
-    error("TODO: Unable to export more than 1 symbol");
-    return;
-  }
-
-  const Defined *sym = exported.front();
-  os << (char)0; // Indicates non-leaf node
-  os << (char)1; // # of children
-  os << sym->getName() << '\0';
-  encodeULEB128(sym->getName().size() + 4, os); // Leaf offset
-
-  // Leaf node
-  uint64_t addr = sym->getVA() + ImageBase;
-  os << (char)(1 + getULEB128Size(addr));
-  os << (char)0; // Flags
-  encodeULEB128(addr, os);
-  os << (char)0; // Terminator
+      trieBuilder.addSymbol(*defined);
+  size = trieBuilder.build();
 }
 
-void ExportSection::writeTo(uint8_t *buf) {
-  memcpy(buf, contents.data(), contents.size());
-}
+void ExportSection::writeTo(uint8_t *buf) { trieBuilder.writeTo(buf); }
 
 SymtabSection::SymtabSection(StringTableSection &stringTableSection)
     : stringTableSection(stringTableSection) {
diff --git a/lld/test/MachO/Inputs/libhello.s b/lld/test/MachO/Inputs/libhello.s
--- a/lld/test/MachO/Inputs/libhello.s
+++ b/lld/test/MachO/Inputs/libhello.s
@@ -1,5 +1,8 @@
 .section __TEXT,__cstring
-.globl _hello_world
+.globl _hello_world, _hello_its_me
 
 _hello_world:
 .asciz "Hello world!\n"
+
+_hello_its_me:
+.asciz "Hello, it's me\n"
diff --git a/lld/test/MachO/dylink.s b/lld/test/MachO/dylink.s
--- a/lld/test/MachO/dylink.s
+++ b/lld/test/MachO/dylink.s
@@ -15,12 +15,16 @@
 # CHECK: movq [[#%u, HELLO_OFF:]](%rip), %rsi
 # CHECK-NEXT: [[#%x, HELLO_RIP:]]:
 
+# CHECK: movq [[#%u, HELLO_ITS_ME_OFF:]](%rip), %rsi
+# CHECK-NEXT: [[#%x, HELLO_ITS_ME_RIP:]]:
+
 # CHECK: movq [[#%u, GOODBYE_OFF:]](%rip), %rsi
 # CHECK-NEXT: [[#%x, GOODBYE_RIP:]]:
 
 # CHECK-LABEL: Bind table:
-# CHECK-DAG: __DATA_CONST __got 0x{{0*}}[[#%x, HELLO_RIP + HELLO_OFF]]     pointer 0 libhello   _hello_world
-# CHECK-DAG: __DATA_CONST __got 0x{{0*}}[[#%x, GOODBYE_RIP + GOODBYE_OFF]] pointer 0 libgoodbye _goodbye_world
+# CHECK-DAG: __DATA_CONST __got 0x{{0*}}[[#%x, HELLO_RIP + HELLO_OFF]]               pointer 0 libhello   _hello_world
+# CHECK-DAG: __DATA_CONST __got 0x{{0*}}[[#%x, HELLO_ITS_ME_RIP + HELLO_ITS_ME_OFF]] pointer 0 libhello   _hello_its_me
+# CHECK-DAG: __DATA_CONST __got 0x{{0*}}[[#%x, GOODBYE_RIP + GOODBYE_OFF]]           pointer 0 libgoodbye _goodbye_world
 
 .section __TEXT,__text
 .globl _main
@@ -34,6 +38,12 @@
 
   movl $0x2000004, %eax # write() syscall
   mov $1, %rdi # stdout
+  movq _hello_its_me@GOTPCREL(%rip), %rsi
+  mov $15, %rdx # length of str
+  syscall
+
+  movl $0x2000004, %eax # write() syscall
+  mov $1, %rdi # stdout
   movq _goodbye_world@GOTPCREL(%rip), %rsi
   mov $15, %rdx # length of str
   syscall
diff --git a/lld/test/MachO/export-trie.s b/lld/test/MachO/export-trie.s
new file mode 100644
--- /dev/null
+++ b/lld/test/MachO/export-trie.s
@@ -0,0 +1,44 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t.o
+# RUN: lld -flavor darwinnew -dylib %t.o -o %t.dylib
+
+# RUN: llvm-objdump --syms --exports-trie %t.dylib | \
+# RUN:   FileCheck %s --check-prefix=EXPORTS
+# EXPORTS-LABEL: SYMBOL TABLE:
+# EXPORTS-DAG:   [[#%x, HELLO_ADDR:]] {{.*}} _hello
+# EXPORTS-DAG:   [[#%x, HELLO_WORLD_ADDR:]] {{.*}} _hello_world
+# EXPORTS-DAG:   [[#%x, HELLO_ITS_ME_ADDR:]] {{.*}} _hello_its_me
+# EXPORTS-DAG:   [[#%x, HELLO_ITS_YOU_ADDR:]] {{.*}} _hello_its_you
+# EXPORTS-LABEL: Exports trie:
+# EXPORTS-DAG:   0x{{0*}}[[#%X, HELLO_ADDR]] _hello
+# EXPORTS-DAG:   0x{{0*}}[[#%X, HELLO_WORLD_ADDR]] _hello_world
+# EXPORTS-DAG:   0x{{0*}}[[#%x, HELLO_ITS_ME_ADDR:]] _hello_its_me
+# EXPORTS-DAG:   0x{{0*}}[[#%x, HELLO_ITS_YOU_ADDR:]] _hello_its_you
+
+## Check that we are sharing prefixes in the trie.
+# RUN: obj2yaml %t.dylib | FileCheck %s
+# CHECK-LABEL: ExportTrie:
+# CHECK: Name: ''
+# CHECK: Name: _hello
+# CHECK: Name: _
+# CHECK: Name: world
+# CHECK: Name: its_
+# CHECK: Name: me
+# CHECK: Name: you
+
+.section __TEXT,__cstring
+.globl _hello, _hello_world, _hello_its_me, _hello_its_you
+
+## Test for when an entire symbol name is a prefix of another.
+_hello:
+.asciz "Hello!\n"
+
+_hello_world:
+.asciz "Hello world!\n"
+
+.data
+_hello_its_me:
+.asciz "Hello, it's me\n"
+
+_hello_its_you:
+.asciz "Hello, it's you\n"
diff --git a/lld/test/MachO/no-exports-dylib.s b/lld/test/MachO/no-exports-dylib.s
new file mode 100644
--- /dev/null
+++ b/lld/test/MachO/no-exports-dylib.s
@@ -0,0 +1,6 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t.o
+# RUN: lld -flavor darwinnew -dylib %t.o -o %t.dylib
+
+# RUN: obj2yaml %t.dylib | FileCheck %s
+# CHECK: export_size: 0
diff --git a/lld/test/MachO/symtab.s b/lld/test/MachO/symtab.s
--- a/lld/test/MachO/symtab.s
+++ b/lld/test/MachO/symtab.s
@@ -14,10 +14,41 @@
 # CHECK-NEXT:     ]
 # CHECK-NEXT:     Value:
 # CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: bar
+# CHECK-NEXT:     Extern
+# CHECK-NEXT:     Type: Section (0xE)
+# CHECK-NEXT:     Section: __text (0x1)
+# CHECK-NEXT:     RefType:
+# CHECK-NEXT:     Flags [ (0x0)
+# CHECK-NEXT:     ]
+# CHECK-NEXT:     Value:
+# CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: foo
+# CHECK-NEXT:     Extern
+# CHECK-NEXT:     Type: Section (0xE)
+# CHECK-NEXT:     Section: __data
+# CHECK-NEXT:     RefType:
+# CHECK-NEXT:     Flags [ (0x0)
+# CHECK-NEXT:     ]
+# CHECK-NEXT:     Value:
+# CHECK-NEXT:   }
 # CHECK-NEXT: ]
 
+.data
+.global foo
+foo:
+  .asciz "Hello world!\n"
+
+.text
+.global bar
 .global _main
 
 _main:
   mov $0, %rax
   ret
+
+bar:
+  mov $2, %rax
+  ret