From: James Clarke <jrtc27@jrtc27.com>
Date: Tue, 8 Oct 2019 02:28:57 +0000 (+0000)
Subject: [ItaniumMangle] Fix mangling of GNU __null in an expression to match GCC
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=8910a5422cbc941bfb7c7af7cf8a2da3025c51c4;p=clang

[ItaniumMangle] Fix mangling of GNU __null in an expression to match GCC

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: erik.pilkington, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68368

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@374013 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/ItaniumMangle.cpp b/lib/AST/ItaniumMangle.cpp
index bea96dec9d..c6f7143251 100644
--- a/lib/AST/ItaniumMangle.cpp
+++ b/lib/AST/ItaniumMangle.cpp
@@ -4273,8 +4273,11 @@ recurse:
   }
 
   case Expr::GNUNullExprClass:
-    // FIXME: should this really be mangled the same as nullptr?
-    // fallthrough
+    // Mangle as if an integer literal 0.
+    Out << 'L';
+    mangleType(E->getType());
+    Out << "0E";
+    break;
 
   case Expr::CXXNullPtrLiteralExprClass: {
     Out << "LDnE";
diff --git a/test/CodeGenCXX/mangle-exprs.cpp b/test/CodeGenCXX/mangle-exprs.cpp
index 6c46402694..1b99272b7f 100644
--- a/test/CodeGenCXX/mangle-exprs.cpp
+++ b/test/CodeGenCXX/mangle-exprs.cpp
@@ -373,3 +373,19 @@ namespace designated_init {
   template<typename T> void f(decltype(T{.a.b[3][1 ... 4] = 9}) x) {}
   void use_f(A a) { f<A>(a); }
 }
+
+namespace null {
+  template <decltype(nullptr) P>
+  void cpp_nullptr(typename enable_if<P == nullptr>::type* = 0) {
+  }
+
+  template <void *P>
+  void gnu_null(typename enable_if<P == __null>::type* = 0) {
+  }
+
+  // CHECK-LABEL: define {{.*}} @_ZN4null11cpp_nullptrILDn0EEEvPN9enable_ifIXeqT_LDnEEvE4typeE
+  template void cpp_nullptr<nullptr>(void *);
+
+  // CHECK-LABEL: define {{.*}} @_ZN4null8gnu_nullILPv0EEEvPN9enable_ifIXeqT_Ll0EEvE4typeE
+  template void gnu_null<nullptr>(void *);
+}