1505029 - Calling MOZ_CAN_RUN_SCRIPT with nsCOMPtr<nsISupports> causes build error

Status: RESOLVED FIXED

(Developer Infrastructure :: Source Code Analysis, defect)

Description

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

I hit these errors:
[task 2018-11-06T10:38:22.991Z] 10:38:22     INFO -  /builds/worker/workspace/build/src/editor/libeditor/HTMLEditorDataTransfer.cpp:1308:34: error: arguments must all be strong refs or parent parameters when calling a function marked as MOZ_CAN_RUN_SCRIPT (including the implicit object argument)
[task 2018-11-06T10:38:22.991Z] 10:38:22     INFO -          InsertObject(bestFlavor, genericDataObj, isSafe,
[task 2018-11-06T10:38:22.991Z] 10:38:22     INFO -          ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
[task 2018-11-06T10:38:22.991Z] 10:38:22     INFO -  /builds/worker/workspace/build/src/editor/libeditor/HTMLEditorDataTransfer.cpp:1451:55: error: arguments must all be strong refs or parent parameters when calling a function marked as MOZ_CAN_RUN_SCRIPT (including the implicit object argument)
[task 2018-11-06T10:38:22.992Z] 10:38:22     INFO -              InsertObject(NS_ConvertUTF16toUTF8(type), object, isSafe,
[task 2018-11-06T10:38:22.992Z] 10:38:22     INFO -              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~
[task 2018-11-06T10:38:22.992Z] 10:38:22     INFO -  2 errors generated.
https://treeherder.mozilla.org/logviewer.html#?job_id=210012990&repo=try&lineNumber=26761

InsertObject() is marked as MOZ_CAN_RUN_SCRIPT newly.

The second error is caused by this code:

  nsCOMPtr<nsISupports> object;
  variant->GetAsISupports(getter_AddRefs(object));
  nsresult rv =
    InsertObject(NS_ConvertUTF16toUTF8(type), object, isSafe,
                 aSourceDoc, aDroppedAt, aDoDeleteSelection);

but changing to as following, the error disappears:

  nsCOMPtr<nsISupports> object;
  variant->GetAsISupports(getter_AddRefs(object));
  nsCOMPtr<BlobImpl> blob = do_QueryInterface(object);
  nsresult rv =
    InsertObject(NS_ConvertUTF16toUTF8(type), blob, isSafe,
                 aSourceDoc, aDroppedAt, aDoDeleteSelection);

https://treeherder.mozilla.org/logviewer.html#?job_id=210069760&repo=try&lineNumber=27645

So, nsCOMPtr<nsISupports> must be accidentally considered as non-strong ref.

Comment 1

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

FYI: The 2nd argument of InsertObject() is nsISupports*.

Comment 2

[Boris Zbarsky [:bzbarsky]]

Attachment: Bug 1505029. Teach our static analysis about nsCOMPtr<nsISupports> being a strong ref. r=andi

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/356a982f5ba4
Teach our static analysis about nsCOMPtr<nsISupports> being a strong ref.  r=mccr8

Comment 4

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/356a982f5ba4