4 files changed, 11 insertions, 3 deletions
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 0be4bad7ee7..5a1b7cfe4fa 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -731,9 +731,11 @@ void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
   }
   if (!D)
     return;
-  // Set visibility for definitions.
+  // Set visibility for definitions, and for declarations if requested globally
+  // or set explicitly.
   LinkageInfo LV = D->getLinkageAndVisibility();
-  if (LV.isVisibilityExplicit() || !GV->isDeclarationForLinker())
+  if (LV.isVisibilityExplicit() || getLangOpts().SetVisibilityForExternDecls ||
+      !GV->isDeclarationForLinker())
     GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
 }
 
diff --git a/clang/lib/Driver/ToolChains/AMDGPU.cpp b/clang/lib/Driver/ToolChains/AMDGPU.cpp
index a03a6073303..b9300bcc42e 100644
--- a/clang/lib/Driver/ToolChains/AMDGPU.cpp
+++ b/clang/lib/Driver/ToolChains/AMDGPU.cpp
@@ -108,5 +108,6 @@ void AMDGPUToolChain::addClangTargetOptions(
                          options::OPT_fvisibility_ms_compat)) {
     CC1Args.push_back("-fvisibility");
     CC1Args.push_back("hidden");
+    CC1Args.push_back("-fapply-global-visibility-to-externs");
   }
 }
diff --git a/clang/lib/Driver/ToolChains/HIP.cpp b/clang/lib/Driver/ToolChains/HIP.cpp
index f55dd2fc04f..cd8ed6118fe 100644
--- a/clang/lib/Driver/ToolChains/HIP.cpp
+++ b/clang/lib/Driver/ToolChains/HIP.cpp
@@ -293,8 +293,10 @@ void HIPToolChain::addClangTargetOptions(
   // Default to "hidden" visibility, as object level linking will not be
   // supported for the foreseeable future.
   if (!DriverArgs.hasArg(options::OPT_fvisibility_EQ,
-                         options::OPT_fvisibility_ms_compat))
+                         options::OPT_fvisibility_ms_compat)) {
     CC1Args.append({"-fvisibility", "hidden"});
+    CC1Args.push_back("-fapply-global-visibility-to-externs");
+  }
 }
 
 llvm::opt::DerivedArgList *
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 4d72924fad2..dbc29e24aee 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -2501,6 +2501,9 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   if (Args.hasArg(OPT_fvisibility_global_new_delete_hidden))
     Opts.GlobalAllocationFunctionVisibilityHidden = 1;
 
+  if (Args.hasArg(OPT_fapply_global_visibility_to_externs))
+    Opts.SetVisibilityForExternDecls = 1;
+
   if (Args.hasArg(OPT_ftrapv)) {
     Opts.setSignedOverflowBehavior(LangOptions::SOB_Trapping);
     // Set the handler, if one is specified.