[debugger] omit exception events for rethrown exceptions in async.

src/interpreter/bytecode-generator.cc

Index: src/interpreter/bytecode-generator.cc
diff --git a/src/interpreter/bytecode-generator.cc b/src/interpreter/bytecode-generator.cc
index bdc5370f5a30ac5779f65f6999c3470256a712cf..6aaec20b85ca169ee4bc248988a334302bd981d4 100644
--- a/src/interpreter/bytecode-generator.cc
+++ b/src/interpreter/bytecode-generator.cc
@@ -2260,7 +2260,12 @@ void BytecodeGenerator::VisitYield(Yield* expr) {
 
     builder()->Bind(&resume_with_throw);
     builder()->SetExpressionPosition(expr);
-    builder()->LoadAccumulatorWithRegister(input).Throw();
+    builder()->LoadAccumulatorWithRegister(input);
+    if (IsAsyncFunction(builder()->literal()->kind())) {

[Michael Starzinger, 2016/07/07 13:04:35]

How would you feel about parameterizing the "Yield" AST node to indicate whether
a throw or a re-throw is requested? This way the AST node itself fully describes
semantics. This avoids having the non-local effect of semantics being different
depending in which AST the context the node appears. WDYT?

[Dan Ehrenberg, 2016/07/07 17:57:31]

Looking forward to async generators, this is a really good idea, as those have
both 'yield' and 'await' Yield AST nodes. I believe the current code is correct,
FWIW.

+      builder()->ReThrow();
+    } else {
+      builder()->Throw();
+    }
 
     builder()->Bind(&resume_with_next);
     builder()->LoadAccumulatorWithRegister(input);