diff --git 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 @@ ExportSection::ExportSection() {
 }
 
 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/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 @@ class ExportSection : public InputSection {
 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/Writer.cpp b/lld/MachO/Writer.cpp
@@ -162,7 +162,7 @@ class LCMain : public LoadCommand {
     auto *c = reinterpret_cast<entry_point_command *>(buf);
     c->cmd = LC_MAIN;
     c->cmdsize = getSize();
-    c->entryoff = config->entry->getVA();
+    c->entryoff = config->entry->getVA() - ImageBase;
     c->stacksize = 0;
   }
 };

diff --git a/lld/test/CMakeLists.txt b/lld/test/CMakeLists.txt
@@ -35,8 +35,9 @@ set(LLD_TEST_DEPS lld)
 if (NOT LLD_BUILT_STANDALONE)
   list(APPEND LLD_TEST_DEPS
     FileCheck count llc llvm-ar llvm-as llvm-bcanalyzer llvm-config llvm-cvtres
-    llvm-dis llvm-dwarfdump llvm-lib llvm-mc llvm-nm llvm-objcopy llvm-objdump
-    llvm-pdbutil llvm-readelf llvm-readobj not obj2yaml opt yaml2obj
+    llvm-dis llvm-dwarfdump llvm-lib llvm-lipo llvm-mc llvm-nm llvm-objcopy
+    llvm-objdump llvm-pdbutil llvm-readelf llvm-readobj not obj2yaml opt
+    yaml2obj
     )
 endif()
 

diff --git 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/alignment-too-large.yaml b/lld/test/MachO/alignment-too-large.yaml
@@ -1,7 +1,7 @@
 # RUN: yaml2obj %s -o %t.o
 # RUN: not lld -flavor darwinnew -o %t %t.o 2>&1 | FileCheck %s
 #
-# CHECK: alignment 32 of section __text is too large
+# CHECK: error: alignment 32 of section __text is too large
 --- !mach-o
 FileHeader:
   magic:           0xFEEDFACF

diff --git a/lld/test/MachO/arch.s b/lld/test/MachO/arch.s
@@ -2,7 +2,7 @@
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-darwin %s -o %t.o
 # RUN: lld -flavor darwinnew -arch x86_64 -o /dev/null %t.o
 # RUN: not lld -flavor darwinnew -arch i386 -o /dev/null %t.o 2>&1 | FileCheck %s
-# CHECK: missing or unsupported -arch i386
+# CHECK: error: missing or unsupported -arch i386
 
 .text
 .global _main

diff --git a/lld/test/MachO/duplicate-symbol.s b/lld/test/MachO/duplicate-symbol.s
@@ -3,7 +3,7 @@
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t-dup.o
 # RUN: not lld -flavor darwinnew -o /dev/null %t-dup.o %t.o 2>&1 | FileCheck %s
 
-# CHECK: duplicate symbol: _main
+# CHECK: error: duplicate symbol: _main
 
 .text
 .global _main

diff --git 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
@@ -32,6 +36,12 @@ _main:
   mov $13, %rdx # length of str
   syscall
 
+  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

diff --git a/lld/test/MachO/entry-symbol.s b/lld/test/MachO/entry-symbol.s
@@ -2,10 +2,10 @@
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t.o
 # RUN: lld -flavor darwinnew -o /dev/null %t.o -e _not_main
 # RUN: not lld -flavor darwinnew -o /dev/null %t.o -e _missing 2>&1 | FileCheck %s
-# RUN: not lld -flavor darwinnew -o /dev/null %t.o 2>&1 | FileCheck %s --check-prefix=DEFAULT_ENTRY
+# RUN: not lld -flavor darwinnew -o /dev/null %t.o 2>&1 | FileCheck %s --check-prefix=DEFAULT-ENTRY
 
-# CHECK: undefined symbol: _missing
-# DEFAULT_ENTRY: undefined symbol: _main
+# CHECK: error: undefined symbol: _missing
+# DEFAULT-ENTRY: error: undefined symbol: _main
 
 .text
 .global _not_main

diff --git a/lld/test/MachO/export-trie.s 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/fat-arch.s b/lld/test/MachO/fat-arch.s
@@ -0,0 +1,16 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=i386-apple-darwin %s -o %t.i386.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t.x86_64.o
+# RUN: llvm-lipo %t.i386.o %t.x86_64.o -create -o %t.fat.o
+# RUN: lld -flavor darwinnew -arch x86_64 -o /dev/null %t.fat.o
+
+# RUN: llvm-lipo %t.i386.o -create -o %t.noarch.o
+# RUN: not lld -flavor darwinnew -arch x86_64 -o /dev/null %t.noarch.o 2>&1 | \
+# RUN:    FileCheck %s -DFILE=%t.noarch.o
+# CHECK: error: unable to find matching architecture in [[FILE]]
+
+.text
+.global _main
+_main:
+  mov $0, %eax
+  ret
diff --git a/lld/test/MachO/invalid-executable.s b/lld/test/MachO/invalid-executable.s
@@ -1,8 +1,8 @@
 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-darwin %s -o %t.o
 # RUN: lld -flavor darwinnew -o %t %t.o
-# RUN: not lld -flavor darwinnew -o /dev/null %t 2>&1 | FileCheck %s
-# CHECK: unhandled file type
+# RUN: not lld -flavor darwinnew -o /dev/null %t 2>&1 | FileCheck %s -DFILE=%t
+# CHECK: error: [[FILE]]: unhandled file type
 
 .text
 .global _main

diff --git a/lld/test/MachO/invalid-fat-narch.s b/lld/test/MachO/invalid-fat-narch.s
@@ -0,0 +1,12 @@
+# REQUIRES: x86
+# RUN: yaml2obj %s -o %t.o
+# RUN: not lld -flavor darwinnew -arch x86_64 -o /dev/null %t.o 2>&1 | \
+# RUN:    FileCheck %s -DFILE=%t.o
+# CHECK: error: [[FILE]]: fat_arch struct extends beyond end of file
+
+!fat-mach-o
+FatHeader:
+  magic:           0xCAFEBABE
+  nfat_arch:       2
+FatArchs:
+Slices:
diff --git a/lld/test/MachO/invalid-fat-offset.s b/lld/test/MachO/invalid-fat-offset.s
@@ -0,0 +1,22 @@
+# REQUIRES: x86
+# RUN: yaml2obj %s -o %t.o
+# RUN: not lld -flavor darwinnew -arch x86_64 -o /dev/null %t.o 2>&1 | \
+# RUN:    FileCheck %s -DFILE=%t.o
+# CHECK: error: [[FILE]]: slice extends beyond end of file
+
+!fat-mach-o
+FatHeader:
+  magic:           0xCAFEBABE
+  nfat_arch:       2
+FatArchs:
+  - cputype:         0x01000007
+    cpusubtype:      0x00000003
+    offset:          0x0000000000001000
+    size:            0
+    align:           12
+  - cputype:         0x00000007
+    cpusubtype:      0x00000003
+    offset:          0x000000000000B000
+    size:            0
+    align:           12
+Slices:
diff --git a/lld/test/MachO/missing-dylib.s b/lld/test/MachO/missing-dylib.s
@@ -2,4 +2,4 @@
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t.o
 # RUN: not lld -flavor darwinnew -Z -o %t -lmissing %t.o 2>&1 | FileCheck %s
 
-# CHECK: library not found for -lmissing
+# CHECK: error: library not found for -lmissing
diff --git a/lld/test/MachO/no-exports-dylib.s 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/no-id-dylink.s b/lld/test/MachO/no-id-dylink.s
@@ -3,7 +3,7 @@
 # RUN: yaml2obj %p/Inputs/no-id-dylib.yaml -o %t/libnoid.dylib
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t/no-id-dylink.o
 # RUN: not lld -flavor darwinnew -o %t/no-id-dylink -Z -L%t -lnoid %t/no-id-dylink.o 2>&1 | FileCheck %s
-# CHECK: dylib {{.*}}libnoid.dylib missing LC_ID_DYLIB load command
+# CHECK: error: dylib {{.*}}libnoid.dylib missing LC_ID_DYLIB load command
 
 .text
 .globl _main

diff --git a/lld/test/MachO/no-such-file.s b/lld/test/MachO/no-such-file.s
@@ -1,4 +1,4 @@
 # REQUIRES: x86
 # RUN: not lld -flavor darwinnew -o /dev/null %t-no-such-file.o 2>&1 | FileCheck %s
 
-# CHECK: cannot open {{.*}}no-such-file.o
+# CHECK: error: cannot open {{.*}}no-such-file.o
diff --git a/lld/test/MachO/relocations.s b/lld/test/MachO/relocations.s
@@ -1,19 +1,34 @@
 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t.o
 # RUN: lld -flavor darwinnew -o %t %t.o
-# RUN: llvm-objdump -d %t | FileCheck %s
+# RUN: llvm-objdump --section-headers --syms -d %t | FileCheck %s
 
-# CHECK: leaq 17(%rip), %rsi
+# CHECK-LABEL: Sections:
+# CHECK:       __cstring {{[0-9a-z]+}} [[#%x, CSTRING_ADDR:]]
+
+# CHECK-LABEL: SYMBOL TABLE:
+# CHECK:       [[#%x, F_ADDR:]] {{.*}} _f
+
+# CHECK-LABEL: <_main>:
+## Test X86_64_RELOC_BRANCH
+# CHECK:       callq 0x[[#%x, F_ADDR]] <_f>
+## Test X86_64_RELOC_SIGNED
+# CHECK:       leaq [[#%u, STR_OFF:]](%rip), %rsi
+# CHECK-NEXT:  [[#%x, CSTRING_ADDR - STR_OFF]]
 
 .section __TEXT,__text
-.globl _main
+.globl _main, _f
 _main:
+  callq _f
+  mov $0, %rax
+  ret
+
+_f:
   movl $0x2000004, %eax # write() syscall
   mov $1, %rdi # stdout
   leaq str(%rip), %rsi
   mov $13, %rdx # length of str
   syscall
-  mov $0, %rax
   ret
 
 .section __TEXT,__cstring

diff --git a/lld/test/MachO/silent-ignore.test b/lld/test/MachO/silent-ignore.test
@@ -5,4 +5,4 @@ RUN:   -no_deduplicate \
 RUN:   -lto_library /lib/foo \
 RUN:   -macosx_version_min 0
 RUN: not lld -flavor darwinnew -v --not-an-ignored-argument 2>&1 | FileCheck %s
-CHECK: unknown argument: --not-an-ignored-argument
+CHECK: error: unknown argument: --not-an-ignored-argument
diff --git 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