Emit an error noting that Clang does not support code generation for
the ternary operator without a left-hand side in C++ (PR7726), from
Jean-Daniel Dupas!


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@111809 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index 4487f17..49deb7b 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -2058,7 +2058,12 @@
     return Builder.CreateSelect(CondV, LHS, RHS, "cond");
   }
 
-
+  if (!E->getLHS() && CGF.getContext().getLangOptions().CPlusPlus) {
+    // Does not support GNU missing condition extension in C++ yet (see #7726)
+    CGF.ErrorUnsupported(E, "conditional operator with missing LHS");
+    return llvm::UndefValue::get(ConvertType(E->getType()));
+  }
+  
   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");