[clang] e0fcdf5 - Revert "In MSVC compatibility mode, friend function declarations behave as function declarations"

[Nico Weber via cfe-commits]

Author: Nico Weber
Date: 2022-05-13T09:48:01-04:00
New Revision: e0fcdf5496ca686c8cebb63b63af86e666b42ab3

URL: https://github.com/llvm/llvm-project/commit/e0fcdf5496ca686c8cebb63b63af86e666b42ab3
DIFF: https://github.com/llvm/llvm-project/commit/e0fcdf5496ca686c8cebb63b63af86e666b42ab3.diff

LOG: Revert "In MSVC compatibility mode, friend function declarations behave as function declarations"

This reverts commit ad47114ad8500c78046161d492ac13a8e3e610eb.
See discussion on https://reviews.llvm.org/D124613.

Added: 
    

Modified: 
    clang/lib/Sema/SemaDecl.cpp
    clang/unittests/AST/ASTImporterTest.cpp

Removed: 
    clang/test/SemaCXX/ms-friend-function-decl.cpp


################################################################################
diff  --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index d599cd619420b..315f328fca6a1 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -9632,15 +9632,11 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
     }
 
     if (isFriend) {
-      // In MSVC mode for older versions of the standard, friend function
-      // declarations behave as declarations
-      bool PerformFriendInjection =
-          getLangOpts().MSVCCompat && !getLangOpts().CPlusPlus20;
       if (FunctionTemplate) {
-        FunctionTemplate->setObjectOfFriendDecl(PerformFriendInjection);
+        FunctionTemplate->setObjectOfFriendDecl();
         FunctionTemplate->setAccess(AS_public);
       }
-      NewFD->setObjectOfFriendDecl(PerformFriendInjection);
+      NewFD->setObjectOfFriendDecl();
       NewFD->setAccess(AS_public);
     }
 

diff  --git a/clang/test/SemaCXX/ms-friend-function-decl.cpp b/clang/test/SemaCXX/ms-friend-function-decl.cpp
deleted file mode 100644
index d146305800738..0000000000000
--- a/clang/test/SemaCXX/ms-friend-function-decl.cpp
+++ /dev/null
@@ -1,45 +0,0 @@
-// RUN: %clang_cc1 -std=c++03 -fms-compatibility -fsyntax-only -verify %s
-// RUN: %clang_cc1 -std=c++17 -fms-compatibility -fsyntax-only -verify %s
-// RUN: %clang_cc1 -std=c++20 -fms-compatibility -fsyntax-only -verify=modern %s
-#if __cplusplus < 202002L
-// expected-no-diagnostics
-#endif
-
-namespace ns {
-
-class C {
-public:
-  template <typename T>
-  friend void funtemp();
-
-  friend void fun();
-
-  void test() {
-    ::ns::fun(); // modern-error {{no member named 'fun' in namespace 'ns'}}
-
-    // modern-error at +3 {{no member named 'funtemp' in namespace 'ns'}}
-    // modern-error at +2 {{expected '(' for function-style cast or type construction}}
-    // modern-error at +1 {{expected expression}}
-    ::ns::funtemp<int>();
-  }
-};
-
-void fun() {
-}
-
-template <typename T>
-void funtemp() {}
-
-} // namespace ns
-
-class Glob {
-public:
-  friend void funGlob();
-
-  void test() {
-    funGlob(); // modern-error {{use of undeclared identifier 'funGlob'}}
-  }
-};
-
-void funGlob() {
-}

diff  --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
index 2cda013a45edc..856010cd4d036 100644
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -2658,10 +2658,7 @@ TEST_P(ImportFriendFunctions, Lookup) {
       getTuDecl("struct X { friend void f(); };", Lang_CXX03, "input0.cc");
   auto *FromD = FirstDeclMatcher<FunctionDecl>().match(FromTU, FunctionPattern);
   ASSERT_TRUE(FromD->isInIdentifierNamespace(Decl::IDNS_OrdinaryFriend));
-  // Before CXX20, MSVC treats friend function declarations as function
-  // declarations
-  ASSERT_EQ(FromTU->getLangOpts().MSVCCompat,
-            FromD->isInIdentifierNamespace(Decl::IDNS_Ordinary));
+  ASSERT_FALSE(FromD->isInIdentifierNamespace(Decl::IDNS_Ordinary));
   {
     auto FromName = FromD->getDeclName();
     auto *Class = FirstDeclMatcher<CXXRecordDecl>().match(FromTU, ClassPattern);
@@ -2705,10 +2702,7 @@ TEST_P(ImportFriendFunctions, LookupWithProtoAfter) {
   auto *FromNormal =
       LastDeclMatcher<FunctionDecl>().match(FromTU, FunctionPattern);
   ASSERT_TRUE(FromFriend->isInIdentifierNamespace(Decl::IDNS_OrdinaryFriend));
-  // Before CXX20, MSVC treats friend function declarations as function
-  // declarations
-  ASSERT_EQ(FromTU->getLangOpts().MSVCCompat,
-            FromFriend->isInIdentifierNamespace(Decl::IDNS_Ordinary));
+  ASSERT_FALSE(FromFriend->isInIdentifierNamespace(Decl::IDNS_Ordinary));
   ASSERT_FALSE(FromNormal->isInIdentifierNamespace(Decl::IDNS_OrdinaryFriend));
   ASSERT_TRUE(FromNormal->isInIdentifierNamespace(Decl::IDNS_Ordinary));
 
@@ -2799,10 +2793,7 @@ TEST_P(ImportFriendFunctions, ImportFriendChangesLookup) {
 
   ASSERT_TRUE(FromNormalF->isInIdentifierNamespace(Decl::IDNS_Ordinary));
   ASSERT_FALSE(FromNormalF->isInIdentifierNamespace(Decl::IDNS_OrdinaryFriend));
-  // Before CXX20, MSVC treats friend function declarations as function
-  // declarations
-  ASSERT_EQ(FromFriendTU->getLangOpts().MSVCCompat,
-            FromFriendF->isInIdentifierNamespace(Decl::IDNS_Ordinary));
+  ASSERT_FALSE(FromFriendF->isInIdentifierNamespace(Decl::IDNS_Ordinary));
   ASSERT_TRUE(FromFriendF->isInIdentifierNamespace(Decl::IDNS_OrdinaryFriend));
   auto LookupRes = FromNormalTU->noload_lookup(FromNormalName);
   ASSERT_TRUE(LookupRes.isSingleResult());