From bc502d9c24f8fce3b90e3fe8a8a9ca18894e68cb Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Wed, 7 Sep 2022 16:06:19 -0700
Subject: [PATCH] Revert D133266 "[MinGW] Reject explicit non-default
 visibility applied to dllexport/dllimport declaration"

This reverts commit 91d8324366f405e871aa8174ab61fc66912964dd.

The combo dllexport protected makes sense and is used by PlayStation.
Will change the patch to allow dllexport protected.
---
 .../include/clang/Basic/DiagnosticFrontendKinds.td |  2 --
 clang/lib/CodeGen/CodeGenModule.cpp                | 10 ++--------
 clang/test/CodeGenCXX/dllstorage-visibility.cpp    | 22 ----------------------
 3 files changed, 2 insertions(+), 32 deletions(-)

diff --git a/clang/include/clang/Basic/DiagnosticFrontendKinds.td b/clang/include/clang/Basic/DiagnosticFrontendKinds.td
index 224c290..50f7e2b 100644
--- a/clang/include/clang/Basic/DiagnosticFrontendKinds.td
+++ b/clang/include/clang/Basic/DiagnosticFrontendKinds.td
@@ -282,8 +282,6 @@ def err_duplicate_mangled_name : Error<
   "definition with same mangled name '%0' as another definition">;
 def err_cyclic_alias : Error<
   "%select{alias|ifunc}0 definition is part of a cycle">;
-def err_non_default_visibility_dllstorage : Error<
-  "non-default visibility cannot be applied to '%0' declaration">;
 def err_ifunc_resolver_return : Error<
   "ifunc resolver function must return a pointer">;
 
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 64a9e9d..f9087cd 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1099,6 +1099,8 @@ llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
 
 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
                                         const NamedDecl *D) const {
+  if (GV->hasDLLExportStorageClass() || GV->hasDLLImportStorageClass())
+    return;
   // Internal definitions always have default visibility.
   if (GV->hasLocalLinkage()) {
     GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
@@ -1109,14 +1111,6 @@ void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
   // Set visibility for definitions, and for declarations if requested globally
   // or set explicitly.
   LinkageInfo LV = D->getLinkageAndVisibility();
-  if (GV->hasDLLExportStorageClass() || GV->hasDLLImportStorageClass()) {
-    // Reject explicit non-default visibility on dllexport/dllimport.
-    if (LV.isVisibilityExplicit() && LV.getVisibility() != DefaultVisibility)
-      getDiags().Report(D->getLocation(),
-                        diag::err_non_default_visibility_dllstorage)
-          << (GV->hasDLLExportStorageClass() ? "dllexport" : "dllimport");
-    return;
-  }
   if (LV.isVisibilityExplicit() || getLangOpts().SetVisibilityForExternDecls ||
       !GV->isDeclarationForLinker())
     GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
diff --git a/clang/test/CodeGenCXX/dllstorage-visibility.cpp b/clang/test/CodeGenCXX/dllstorage-visibility.cpp
index 0e3c32e..8f34afb 100644
--- a/clang/test/CodeGenCXX/dllstorage-visibility.cpp
+++ b/clang/test/CodeGenCXX/dllstorage-visibility.cpp
@@ -4,18 +4,10 @@
 // RUN: %clang_cc1 -emit-llvm -triple x86_64-windows-gnu -fdeclspec -fvisibility-inlines-hidden -o - %s | FileCheck %s --check-prefix=GNU
 // RUN: %clang_cc1 -emit-llvm -triple x86_64-windows-gnu -fdeclspec -fvisibility=hidden -o - %s | FileCheck %s --check-prefix=GNU
 
-// RUN: %clang_cc1 -emit-llvm-only -verify -triple x86_64-windows-gnu -fdeclspec -DERR1 -o - %s
-// RUN: %clang_cc1 -emit-llvm-only -verify -triple x86_64-windows-gnu -fdeclspec -fvisibility=hidden -DERR1 -o - %s
-// RUN: %clang_cc1 -emit-llvm-only -verify -triple x86_64-windows-gnu -fdeclspec -DERR2 -o - %s
-
 #define CONCAT2(x, y) x##y
 #define CONCAT(x, y) CONCAT2(x, y)
 #define USE(func) void CONCAT(use, __LINE__)() { func(); }
 
-#define HIDDEN __attribute__((visibility("hidden")))
-#define PROTECTED __attribute__((visibility("protected")))
-#define DEFAULT __attribute__((visibility("default")))
-
 // MSVC-DAG: declare dllimport void @"?bar@foo@@QEAAXXZ"(
 // GNU-DAG: define linkonce_odr hidden void @_ZN3foo3barEv(
 
@@ -32,17 +24,3 @@ __attribute__((dllexport)) void exported() {}
 // GNU-DAG: define weak_odr dso_local dllexport void @_Z15exported_inlinev(
 __declspec(dllexport) inline void exported_inline() {}
 USE(exported_inline)
-
-#if defined(ERR1)
-// expected-error@+1 {{non-default visibility cannot be applied to 'dllimport' declaration}}
-__attribute__((dllimport)) HIDDEN void imported_hidden();
-
-__attribute__((dllexport)) DEFAULT void exported_default() {}
-// expected-error@+1 {{non-default visibility cannot be applied to 'dllexport' declaration}}
-__attribute__((dllexport)) HIDDEN void exported_hidden() { imported_hidden(); }
-#elif defined(ERR2)
-struct PROTECTED C {
-  // expected-error@+1 {{non-default visibility cannot be applied to 'dllexport' declaration}}
-  __attribute__((dllexport)) void exported_protected() {}
-};
-#endif
-- 
2.7.4