commit 62e9370d9da9ee4f675da52d559a79c93c30642e
author David Majnemer <david.majnemer@gmail.com> Sun Nov 03 23:51:28 2013 +0000
committer David Majnemer <david.majnemer@gmail.com> Sun Nov 03 23:51:28 2013 +0000
tree ae46d434139a95f6bc110cb6b080784297446bc8
parent 3a50d847e098f36e3bf8bc14eea07a6cc35f7803

Sema: Do not allow overloading between methods based on restrict

If the sole distinction between two declarations is that one has a
__restrict qualifier then we should not consider it to be an overload.

Instead, we will consider it as an incompatible redeclaration which is
similar to how MSVC, ICC and GCC would handle it.

This fixes PR17786.

N.B. We must not mangle in __restrict into method qualifiers becase we
don't allow overloading between such declarations anymore.  To do
otherwise would be a violation of the Itanium ABI.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193964 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AST/ItaniumMangle.cpp

diff --git a/lib/AST/ItaniumMangle.cpp b/lib/AST/ItaniumMangle.cpp
index 21a6c10..953bff2 100644
--- a/lib/AST/ItaniumMangle.cpp
+++ b/lib/AST/ItaniumMangle.cpp
@@ -1239,7 +1239,12 @@
 
   Out << 'N';
   if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(ND)) {
-    mangleQualifiers(Qualifiers::fromCVRMask(Method->getTypeQualifiers()));
+    Qualifiers MethodQuals =
+        Qualifiers::fromCVRMask(Method->getTypeQualifiers());
+    // We do not consider restrict a distinguishing attribute for overloading
+    // purposes so we must not mangle it.
+    MethodQuals.removeRestrict();
+    mangleQualifiers(MethodQuals);
     mangleRefQualifier(Method->getRefQualifier());
   }
   

lib/Sema/SemaOverload.cpp

diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 20cfb00..c6bcf44 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -1071,11 +1071,16 @@
     // function yet (because we haven't yet resolved whether this is a static
     // or non-static member function). Add it now, on the assumption that this
     // is a redeclaration of OldMethod.
+    unsigned OldQuals = OldMethod->getTypeQualifiers();
     unsigned NewQuals = NewMethod->getTypeQualifiers();
     if (!getLangOpts().CPlusPlus1y && NewMethod->isConstexpr() &&
         !isa<CXXConstructorDecl>(NewMethod))
       NewQuals |= Qualifiers::Const;
-    if (OldMethod->getTypeQualifiers() != NewQuals)
+
+    // We do not allow overloading based off of '__restrict'.
+    OldQuals &= ~Qualifiers::Restrict;
+    NewQuals &= ~Qualifiers::Restrict;
+    if (OldQuals != NewQuals)
       return true;
   }
 

test/CodeGenCXX/mangle.cpp

diff --git a/test/CodeGenCXX/mangle.cpp b/test/CodeGenCXX/mangle.cpp
index 4e6dbf5..d836f36 100644
--- a/test/CodeGenCXX/mangle.cpp
+++ b/test/CodeGenCXX/mangle.cpp
@@ -942,3 +942,12 @@
   void g(zed<&foo::bar>*)
   {}
 }
+
+namespace test44 {
+  struct foo { void bar() __restrict { }; } obj;
+
+  void f() {
+    obj.bar();
+  }
+  // CHECK-LABEL: define linkonce_odr void @_ZN6test443foo3barEv(%"struct.test44::foo"* %this)
+}

test/SemaCXX/overload-decl.cpp

diff --git a/test/SemaCXX/overload-decl.cpp b/test/SemaCXX/overload-decl.cpp
index 0153620..fdb14cb 100644
--- a/test/SemaCXX/overload-decl.cpp
+++ b/test/SemaCXX/overload-decl.cpp
@@ -29,6 +29,11 @@
   static void g(float); // expected-note {{previous declaration is here}}
   static void g(int); // expected-error {{static and non-static member functions with the same parameter types cannot be overloaded}}
   static void g(float); // expected-error {{class member cannot be redeclared}}
+
+  void h(); // expected-note {{previous declaration is here}} \
+               expected-note {{previous declaration is here}}
+  void h() __restrict; // expected-error {{class member cannot be redeclared}} \
+                          expected-error {{conflicting types for 'h'}}
 };
 
 int main() {} // expected-note {{previous definition is here}}