Index: ELF/Config.h
===================================================================
--- ELF/Config.h
+++ ELF/Config.h
@@ -10,6 +10,7 @@
 #ifndef LLD_ELF_CONFIG_H
 #define LLD_ELF_CONFIG_H
 
+#include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/ELF.h"
 
@@ -36,6 +37,8 @@
   llvm::StringRef Sysroot;
   std::string RPath;
   std::vector<llvm::StringRef> InputSearchPaths;
+  // If the name of an undefined symbol is in this list, it should be replaced.
+  llvm::StringMap<std::string> UndefSymNameReplacement;
   bool AllowMultipleDefinition;
   bool DiscardAll;
   bool DiscardLocals;
Index: ELF/Driver.cpp
===================================================================
--- ELF/Driver.cpp
+++ ELF/Driver.cpp
@@ -176,6 +176,13 @@
   if (auto *Arg = Args.getLastArg(OPT_m))
     setELFType(Arg->getValue());
 
+  for (auto *Arg : Args.filtered(OPT_wrap)) {
+    Config->UndefSymNameReplacement.insert(std::make_pair(
+        Arg->getValue(), (Twine("__wrap_") + Arg->getValue()).str()));
+    Config->UndefSymNameReplacement.insert(std::make_pair(
+        (Twine("__real_") + Arg->getValue()).str(), Arg->getValue()));
+  }
+
   Config->AllowMultipleDefinition = Args.hasArg(OPT_allow_multiple_definition);
   Config->DiscardAll = Args.hasArg(OPT_discard_all);
   Config->DiscardLocals = Args.hasArg(OPT_discard_locals);
Index: ELF/InputFiles.cpp
===================================================================
--- ELF/InputFiles.cpp
+++ ELF/InputFiles.cpp
@@ -9,6 +9,7 @@
 
 #include "InputFiles.h"
 #include "InputSection.h"
+#include "Config.h"
 #include "Error.h"
 #include "Symbols.h"
 #include "llvm/ADT/STLExtras.h"
@@ -159,8 +160,13 @@
   switch (SecIndex) {
   case SHN_ABS:
     return new (Alloc) DefinedAbsolute<ELFT>(Name, *Sym);
-  case SHN_UNDEF:
-    return new (Alloc) Undefined<ELFT>(Name, *Sym);
+  case SHN_UNDEF: {
+    auto Replacement = Config->UndefSymNameReplacement.find(Name);
+    if (Replacement != Config->UndefSymNameReplacement.end())
+      return new (Alloc) Undefined<ELFT>(Replacement->second, *Sym);
+    else
+      return new (Alloc) Undefined<ELFT>(Name, *Sym);
+  }
   case SHN_COMMON:
     return new (Alloc) DefinedCommon<ELFT>(Name, *Sym);
   case SHN_XINDEX:
Index: ELF/Options.td
===================================================================
--- ELF/Options.td
+++ ELF/Options.td
@@ -82,6 +82,9 @@
 def whole_archive : Flag<["--"], "whole-archive">,
   HelpText<"Force load of all members in a static library">;
 
+def wrap : Separate<["--", "-"], "wrap">, MetaVarName<"<symbol>">,
+  HelpText<"Use a wrapper function for symbol">;
+
 // Aliases
 def alias_Bdynamic_call_shared: Flag<["-"], "call_shared">, Alias<Bdynamic>;
 def alias_Bdynamic_dy: Flag<["-"], "dy">, Alias<Bdynamic>;
@@ -99,6 +102,7 @@
 def alias_soname_h : Separate<["-"], "h">, Alias<soname>;
 def alias_soname_soname : Separate<["-"], "soname">, Alias<soname>;
 def alias_undefined_u : Separate<["-"], "u">, Alias<undefined>;
+def alias_wrap_wrap : Joined<["--", "-"], "wrap=">, Alias<wrap>;
 
 // Options listed below are silently ignored now.
 def O3 : Flag<["-"], "O3">;
Index: test/elf2/Inputs/wrap.s
===================================================================
--- /dev/null
+++ test/elf2/Inputs/wrap.s
@@ -0,0 +1,4 @@
+.globl foo,__wrap_foo,__real_foo;
+foo        = 0x11000
+__wrap_foo = 0x11010
+__real_foo = 0x11020
Index: test/elf2/wrap.s
===================================================================
--- /dev/null
+++ test/elf2/wrap.s
@@ -0,0 +1,19 @@
+// REQUIRES: x86
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/wrap.s -o %t2
+
+// 1) Should replace used symbols foo -> __wrap_foo, __real_foo -> foo
+// 2) Should not fail on undefined symbol if it isn't used (bar)
+// RUN: lld -flavor gnu2 -o %t3 %t %t2 -wrap foo -wrap bar
+// RUN: llvm-objdump -d -print-imm-hex %t3 | FileCheck %s
+
+// CHECK: _start:
+// CHECK-NEXT: movl $0x11010, %edx
+// CHECK-NEXT: movl $0x11010, %edx
+// CHECK-NEXT: movl $0x11000, %edx
+
+.global _start;
+_start:
+  movl $foo, %edx
+  movl $__wrap_foo, %edx
+  movl $__real_foo, %edx
Index: test/elf2/wrap2.s
===================================================================
--- /dev/null
+++ test/elf2/wrap2.s
@@ -0,0 +1,31 @@
+// REQUIRES: x86
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t
+
+// RUN: lld -flavor gnu2 -shared -o %t2 %t -wrap foo -wrap bar -wrap baz
+// RUN: llvm-readobj -symbols %t2 | FileCheck %s --check-prefix=CHECK1
+// RUN: llvm-readobj -symbols %t2 | FileCheck %s --check-prefix=CHECK2
+// Check aliases of the switch
+// RUN: lld -flavor gnu2 -shared -o %t2 %t --wrap foo -wrap=bar --wrap=baz
+// RUN: llvm-readobj -symbols %t2 | FileCheck %s --check-prefix=CHECK1
+// RUN: llvm-readobj -symbols %t2 | FileCheck %s --check-prefix=CHECK2
+
+// CHECK1: Symbols [
+// CHECK1-DAG: Name: __wrap_foo
+// CHECK1-DAG: Name: bar
+// CHECK1-DAG: Name: __wrap_baz
+// CHECK1: ]
+
+// CHECK2: Symbols [
+// CHECK2-NOT: Name: foo
+// CHECK2-NOT: Name: __real_foo
+// CHECK2-NOT: Name: __wrap_bar
+// CHECK2-NOT: Name: __real_bar
+// CHECK2-NOT: Name: baz
+// CHECK2-NOT: Name: __real_baz
+// CHECK2: ]
+
+.global _start;
+_start:
+  jmp foo@PLT
+  jmp __real_bar@PLT
+  jmp __wrap_baz@PLT