API functions returning Promises should not throw exceptions.

Source/bindings/v8/V8BindingMacros.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 68 matching lines @@
     type var;                                                       \
     {                                                               \
         v8::TryCatch block;                                         \
         var = (value);                                              \
         if (UNLIKELY(block.HasCaught()))                            \
             exceptionState.rethrowV8Exception(block.Exception());   \
         if (UNLIKELY(exceptionState.throwIfNeeded()))               \
             return;                                                 \
     }
 
+#define V8TRYCATCH_VOID_PROMISE(type, var, value, info)                                \
+    type var;                                                                          \
+    {                                                                                  \
+        v8::TryCatch block;                                                            \
+        var = (value);                                                                 \
+        if (UNLIKELY(block.HasCaught())) {                                             \
+            v8::Isolate* isolate = info.GetIsolate();                                  \
+            ScriptPromise promise = ScriptPromise::reject(block.Exception(), isolate); \
+            v8SetReturnValue(info, promise.v8Value());                                 \
+            return;                                                                    \
+        }                                                                              \
+    }
+
+#define V8TRYCATCH_EXCEPTION_VOID_PROMISE(type, var, value, info, exceptionState) \

[haraken, 2014/04/10 12:09:17]

The macro names in this file are getting broken... What does V8TRYCATCH_A_B_C
mean?

I'd be happy if you could clean up the names before landing this CL.

[Nils Barth (inactive), 2014/04/11 01:03:41]

I'll grab this.

My suggestion:
V8TRYCATCH[_TYPE][_args...]
...i.e.:
V8TRYCATCH[_TYPE][_EXCEPTION][_RETURN]

Thus we'd rename:
V8TRYCATCH_EXCEPTION_VOID => V8TRYCATCH_VOID_EXCEPTION

Also, V8TRYCATCH_FOR_V8STRINGRESOURCE* does *not* TRYCATCH,
so these should just be:
V8STRINGRESOURCE_RETURN
V8STRINGRESOURCE_VOID

So for this CL:
V8TRYCATCH_EXCEPTION_VOID_PROMISE
=>
V8TRYCATCH_VOID_INFO_EXCEPTION
etc.

[Nils Barth (inactive), 2014/04/11 02:19:38]

Posted:
Rename V8TRYCATCH_* macros in v8/V8BindingMacros.h
https://codereview.chromium.org/234403004

[yhirano, 2014/04/11 10:19:04]

Done.

+    type var;                                                                     \
+    {                                                                             \
+        v8::TryCatch block;                                                       \
+        var = (value);                                                            \
+        v8::Isolate* isolate = info.GetIsolate();                                 \
+        if (UNLIKELY(block.HasCaught()))                                          \
+            exceptionState.rethrowV8Exception(block.Exception());                 \
+        if (UNLIKELY(exceptionState.hadException())) {                            \

[haraken, 2014/04/10 12:09:17]

Shouldn't this be exceptionState.throwIfNeeded()?

[yhirano, 2014/04/11 10:19:04]

What I want to do is returning a Promise rejected with the exception that the
exceptionState has. So I think its' OK.

+            v8SetReturnValue(info, exceptionState.rejectedPromise().v8Value());   \
+            return;                                                               \
+        }                                                                         \
+    }
+
 #define V8TRYCATCH_FOR_V8STRINGRESOURCE_RETURN(type, var, value, retVal) \
     type var(value);                                                     \
     if (UNLIKELY(!var.prepare()))                                        \
         return retVal;
 
 #define V8TRYCATCH_FOR_V8STRINGRESOURCE_VOID(type, var, value) \
     type var(value);                                           \
     if (UNLIKELY(!var.prepare()))                              \
         return;
 
+#define V8TRYCATCH_FOR_V8STRINGRESOURCE_VOID_PROMISE(type, var, value, info)           \
+    type var(value);                                                                   \
+    {                                                                                  \
+        v8::TryCatch block;                                                            \
+        var.prepare();                                                                 \
+        if (UNLIKELY(block.HasCaught())) {                                             \
+            v8::Isolate* isolate = info.GetIsolate();                                  \
+            ScriptPromise promise = ScriptPromise::reject(block.Exception(), isolate); \
+            v8SetReturnValue(info, promise.v8Value());                                 \
+            return;                                                                    \
+        }                                                                              \
+    }
+
 } // namespace WebCore
 
 #endif // V8BindingMacros_h