commit 3c5cd15da59d084ee441ac1512907a73f0e1f2bd
author Richard Smith <richard-llvm@metafoo.co.uk> Tue Mar 05 08:30:04 2013 +0000
committer Richard Smith <richard-llvm@metafoo.co.uk> Tue Mar 05 08:30:04 2013 +0000
tree 4de5ae5a980587fb3238999fedb93abd4b6000f3
parent 4b02dff7aebb98d2d60b2ff4d3fc86109213128c

Don't emit calls to virtual [[noreturn]] functions as noreturn; overrides of a
[[noreturn]] function are not required to also be [[noreturn]]. We still emit
calls to virtual __attribute__((noreturn)) functions as noreturn; unlike GCC,
we do require overriders to also be noreturn for that attribute.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176476 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CGCall.cpp

diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index 4e8e724..6aabd64 100644
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -993,7 +993,10 @@
       const FunctionProtoType *FPT = Fn->getType()->getAs<FunctionProtoType>();
       if (FPT && FPT->isNothrow(getContext()))
         FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
-      if (Fn->isNoReturn())
+      // Don't use [[noreturn]] or _Noreturn for a call to a virtual function.
+      // These attributes are not inherited by overloads.
+      const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Fn);
+      if (Fn->isNoReturn() && !(AttrOnCallSite && MD && MD->isVirtual()))
         FuncAttrs.addAttribute(llvm::Attribute::NoReturn);
     }
 

test/CodeGenCXX/virtual-function-calls.cpp

diff --git a/test/CodeGenCXX/virtual-function-calls.cpp b/test/CodeGenCXX/virtual-function-calls.cpp
index 46e7b2d..e1b380f 100644
--- a/test/CodeGenCXX/virtual-function-calls.cpp
+++ b/test/CodeGenCXX/virtual-function-calls.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 %s -std=c++11 -emit-llvm -o - | FileCheck %s
 
 // PR5021
 namespace PR5021 {
@@ -36,3 +36,16 @@
     b->f();
   }
 }
+
+namespace VirtualNoreturn {
+  struct A {
+    [[noreturn]] virtual void f();
+  };
+
+  // CHECK: @_ZN15VirtualNoreturn1f
+  void f(A *p) {
+    p->f();
+    // CHECK: call void %{{[^#]*$}}
+    // CHECK-NOT: unreachable
+  }
+}