Index: clang/include/clang/Basic/CodeGenOptions.def
===================================================================
--- clang/include/clang/Basic/CodeGenOptions.def
+++ clang/include/clang/Basic/CodeGenOptions.def
@@ -162,6 +162,7 @@
 CODEGENOPT(NoTrappingMath    , 1, 0) ///< Set when -fno-trapping-math is enabled.
 CODEGENOPT(NoNaNsFPMath      , 1, 0) ///< Assume FP arguments, results not NaN.
 CODEGENOPT(CorrectlyRoundedDivSqrt, 1, 0) ///< -cl-fp32-correctly-rounded-divide-sqrt
+CODEGENOPT(UniqueInternalFuncNames, 1, 0) ///< Internal Linkage functions get unique names.
 
 /// When false, this attempts to generate code as if the result of an
 /// overflowing conversion matches the overflowing behavior of a target's native
Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -1971,6 +1971,12 @@
 def fno_unique_section_names : Flag <["-"], "fno-unique-section-names">,
   Group<f_Group>, Flags<[CC1Option]>;
 
+def funique_internal_funcnames : Flag <["-"], "funique-internal-funcnames">,
+  Group<f_Group>, Flags<[CC1Option]>,
+  HelpText<"Uniqueify Internal Linkage Function Names">;
+def fno_unique_internal_funcnames : Flag <["-"], "fno-unique-internal-funcnames">,
+  Group<f_Group>;
+
 def fstrict_return : Flag<["-"], "fstrict-return">, Group<f_Group>,
   Flags<[CC1Option]>,
   HelpText<"Always treat control flow paths that fall off the end of a "
Index: clang/lib/CodeGen/CodeGenModule.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenModule.cpp
+++ clang/lib/CodeGen/CodeGenModule.cpp
@@ -1124,6 +1124,23 @@
   const auto *ND = cast<NamedDecl>(GD.getDecl());
   std::string MangledName = getMangledNameImpl(*this, GD, ND);
 
+  // With option -funique-internal-funcnames, functions with internal linkage
+  // should get unique names.  Use the hash of module name to get a unique
+  // identifier as this is a best-effort solution.
+  if (getCodeGenOpts().UniqueInternalFuncNames &&
+      dyn_cast<FunctionDecl>(GD.getDecl()) &&
+      getFunctionLinkage(GD) == llvm::GlobalValue::InternalLinkage &&
+      !getModule().getSourceFileName().empty()) {
+    llvm::MD5 Md5;
+    Md5.update(getModule().getSourceFileName());
+    llvm::MD5::MD5Result R;
+    Md5.final(R);
+    SmallString<32> Str;
+    llvm::MD5::stringifyResult(R, Str);
+    std::string UniqueSuffix = ("." + Str).str();
+    MangledName += UniqueSuffix;
+  }
+
   // Ensure either we have different ABIs between host and device compilations,
   // says host compilation following MSVC ABI but device compilation follows
   // Itanium C++ ABI or, if they follow the same ABI, kernel names after
Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -4222,6 +4222,8 @@
         options::OPT_fno_function_sections,
         options::OPT_fdata_sections,
         options::OPT_fno_data_sections,
+        options::OPT_funique_internal_funcnames,
+        options::OPT_fno_unique_internal_funcnames,
         options::OPT_funique_section_names,
         options::OPT_fno_unique_section_names,
         options::OPT_mrestrict_it,
@@ -4819,6 +4821,10 @@
                     options::OPT_fno_unique_section_names, true))
     CmdArgs.push_back("-fno-unique-section-names");
 
+  if (Args.hasFlag(options::OPT_funique_internal_funcnames,
+                   options::OPT_fno_unique_internal_funcnames, false))
+    CmdArgs.push_back("-funique-internal-funcnames");
+
   Args.AddLastArg(CmdArgs, options::OPT_finstrument_functions,
                   options::OPT_finstrument_functions_after_inlining,
                   options::OPT_finstrument_function_entry_bare);
Index: clang/lib/Frontend/CompilerInvocation.cpp
===================================================================
--- clang/lib/Frontend/CompilerInvocation.cpp
+++ clang/lib/Frontend/CompilerInvocation.cpp
@@ -958,6 +958,7 @@
   Opts.StackSizeSection = Args.hasArg(OPT_fstack_size_section);
   Opts.UniqueSectionNames = !Args.hasArg(OPT_fno_unique_section_names);
 
+  Opts.UniqueInternalFuncNames = Args.hasArg(OPT_funique_internal_funcnames);
   Opts.MergeFunctions = Args.hasArg(OPT_fmerge_functions);
 
   Opts.NoUseJumpTables = Args.hasArg(OPT_fno_jump_tables);
Index: clang/test/CodeGen/unique-internal-funcnames.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/unique-internal-funcnames.c
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 -triple x86_64 -S -emit-llvm -o - < %s | FileCheck %s --check-prefix=PLAIN
+// RUN: %clang_cc1 -triple x86_64 -S -emit-llvm -funique-internal-funcnames -o - < %s | FileCheck %s --check-prefix=UNIQUE
+
+static int foo() {
+  return 0;
+}
+
+int (*bar())() {
+  return foo;
+}
+
+// PLAIN: @foo()
+// UNIQUE-NOT: @foo()
+// UNIQUE: @foo.{{[0-9a-f]+}}()
Index: clang/test/Driver/funique-internal-funcnames.c
===================================================================
--- /dev/null
+++ clang/test/Driver/funique-internal-funcnames.c
@@ -0,0 +1,4 @@
+// RUN: %clang -### -funique-internal-funcnames %s -c 2>&1 | FileCheck -check-prefix=CHECK-OPT %s
+// RUN: %clang -### -funique-internal-funcnames -fno-unique-internal-funcnames %s -c 2>&1 | FileCheck -check-prefix=CHECK-NOOPT %s
+// CHECK-OPT: "-funique-internal-funcnames"
+// CHECK-NOOPT-NOT: {{-funique-internal-funcnames}}