Don't crash in IRGen if a conditional with 'throw' in one of its branches is

used as a branch condition.

llvm-svn: 181368

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -928,6 +928,16 @@ void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond,
     return;
   }
 
+  if (const CXXThrowExpr *Throw = dyn_cast<CXXThrowExpr>(Cond)) {
+    // Conditional operator handling can give us a throw expression as a
+    // condition for a case like:
+    //   br(c ? throw x : y, t, f) -> br(c, br(throw x, t, f), br(y, t, f)
+    // Fold this to:
+    //   br(c, throw x, br(y, t, f))
+    EmitCXXThrowExpr(Throw, /*KeepInsertionPoint*/false);
+    return;
+  }
+
   // Emit the code with the fully general case.
   llvm::Value *CondV = EvaluateExprAsBool(Cond);
   Builder.CreateCondBr(CondV, TrueBlock, FalseBlock);