Index: ELF/Config.h
===================================================================
--- ELF/Config.h
+++ ELF/Config.h
@@ -13,6 +13,7 @@
 #include "llvm/ADT/CachedHashString.h"
 #include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSet.h"
 #include "llvm/Support/ELF.h"
 
 #include <vector>
@@ -34,8 +35,8 @@
 // For --build-id.
 enum class BuildIdKind { None, Fast, Md5, Sha1, Hexstring, Uuid };
 
-// For --discard-{all,locals,none}.
-enum class DiscardPolicy { Default, All, Locals, None };
+// For --discard-{all,locals,none} and --retain-symbols-file.
+enum class DiscardPolicy { Default, All, Locals, RetainFile, None };
 
 // For --strip-{all,debug}.
 enum class StripPolicy { None, All, Debug };
@@ -84,6 +85,7 @@
   llvm::StringRef OutputFile;
   llvm::StringRef SoName;
   llvm::StringRef Sysroot;
+  llvm::StringSet<> RetainSymbolsFile;
   std::string RPath;
   std::vector<VersionDefinition> VersionDefinitions;
   std::vector<llvm::StringRef> AuxiliaryList;
Index: ELF/Driver.cpp
===================================================================
--- ELF/Driver.cpp
+++ ELF/Driver.cpp
@@ -474,18 +474,31 @@
   return SortSectionPolicy::Default;
 }
 
+static std::vector<StringRef> getLines(MemoryBufferRef MB) {
+  SmallVector<StringRef, 0> Arr;
+  MB.getBuffer().split(Arr, '\n', INT32_MAX, /*KeepEmpty*/ false);
+  return {Arr.begin(), Arr.end()};
+}
+
 // Parse the --symbol-ordering-file argument. File has form:
 // symbolName1
 // [...]
 // symbolNameN
 static void parseSymbolOrderingList(MemoryBufferRef MB) {
   unsigned I = 0;
-  SmallVector<StringRef, 0> Arr;
-  MB.getBuffer().split(Arr, '\n');
-  for (StringRef S : Arr)
+  for (StringRef S : getLines(MB))
     Config->SymbolOrderingFile.insert({CachedHashStringRef(S.trim()), I++});
 }
 
+// Parse the --retain-symbols-file argument. File has form:
+// symbolName1
+// [...]
+// symbolNameN
+static void parseRetainSymbolsList(MemoryBufferRef MB) {
+  for (StringRef S : getLines(MB))
+    Config->RetainSymbolsFile.insert(S.trim());
+}
+
 // Initializes Config members by the command line options.
 void LinkerDriver::readConfigs(opt::InputArgList &Args) {
   for (auto *Arg : Args.filtered(OPT_L))
@@ -632,6 +645,14 @@
     if (Optional<MemoryBufferRef> Buffer = readFile(Arg->getValue()))
       parseSymbolOrderingList(*Buffer);
 
+  // If --retain-symbol-file is used, we'll retail only the symbols listed in
+  // the file and discard all others.
+  if (auto *Arg = Args.getLastArg(OPT_retain_symbols_file)) {
+    Config->Discard = DiscardPolicy::RetainFile;
+    if (Optional<MemoryBufferRef> Buffer = readFile(Arg->getValue()))
+      parseRetainSymbolsList(*Buffer);
+  }
+
   for (auto *Arg : Args.filtered(OPT_export_dynamic_symbol))
     Config->VersionScriptGlobals.push_back(
         {Arg->getValue(), /*IsExternCpp*/ false, /*HasWildcard*/ false});
Index: ELF/Options.td
===================================================================
--- ELF/Options.td
+++ ELF/Options.td
@@ -176,6 +176,9 @@
 
 def relocatable: F<"relocatable">, HelpText<"Create relocatable object file">;
 
+def retain_symbols_file: J<"retain-symbols-file=">, MetaVarName<"<file>">,
+  HelpText<"Retain only the symbols listed in the file">;
+
 def script: S<"script">, HelpText<"Read linker script">;
 
 def section_start: S<"section-start">, MetaVarName<"<address>">,
Index: ELF/Writer.cpp
===================================================================
--- ELF/Writer.cpp
+++ ELF/Writer.cpp
@@ -422,6 +422,11 @@
   if (!B.isLocal() && !B.symbol()->IsUsedInRegularObj)
     return false;
 
+  // If --retain-symbols-file used, we do not keep include unlisted symbols.
+  if (Config->Discard == DiscardPolicy::RetainFile)
+    if (!Config->RetainSymbolsFile.count(CachedHashString(B.getName())))
+      return false;
+
   if (auto *D = dyn_cast<DefinedRegular<ELFT>>(&B)) {
     // Always include absolute symbols.
     if (!D->Section)
Index: test/ELF/retain-symbols-file.s
===================================================================
--- test/ELF/retain-symbols-file.s
+++ test/ELF/retain-symbols-file.s
@@ -0,0 +1,40 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t
+# RUN: echo "bar" > %t_retain.txt
+# RUN: echo "foo" >> %t_retain.txt
+# RUN: ld.lld -shared --retain-symbols-file=%t_retain.txt %t -o %t2
+# RUN: llvm-readobj -s -sd -t %t2 | FileCheck %s
+
+# CHECK:       Symbols [
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name:  (0)
+# CHECK:        Symbol {
+# CHECK-NEXT:     Name: bar
+# CHECK:        Symbol {
+# CHECK-NEXT:     Name: foo
+# CHECK-NOT:    Symbol
+
+.text
+.globl _start
+_start:
+call zed@PLT
+call und@PLT
+
+.globl foo
+.type foo,@function
+foo:
+retq
+
+.globl bar
+.type bar,@function
+bar:
+retq
+
+.globl zed
+.type zed,@function
+zed:
+retq
+
+.type loc,@function
+loc:
+retq