613766 - Fallible operator new doesn't compile with MSVC

Status: RESOLVED WORKSFORME

(Core :: XPCOM, defect)

Description

[Ben Turner (not reading bugmail, use the needinfo flag!)]

The following line compiles and runs just fine on OS X (and linux, I assume):

  Block *b = new (fallible_t()) Block();

MSVC instead issues several errors:

  * <filename>: error C2066: cast to function type is illegal
  * <filename>: error C2440: 'initializing' : cannot convert from
      'mozilla::fallible_t (__cdecl **)(void)' to 'EdgePool::Block *'
       Types pointed to are unrelated; conversion requires
         reinterpret_cast, C-style cast or function-style cast

Am I doing something wrong or is fallible new no longer possible with MSVC?

The cycle collector was written with OOM taken into consideration and we'd like to make it handle OOM gracefully without aborting. This might need to block.

Comment 1

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Does it work with mozilla::fallible_t() ?  (Could it be a namespace issue?)

Comment 2

[Ben Turner (not reading bugmail, use the needinfo flag!)]

No, it's able to see mozilla::fallible_t in that error message.

Comment 3

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

I don't see anything wrong with what we're doing.  Could you try

  static fallible_t fallible = fallible_t();
  Block* b = new (fallible) Block();

?  Maybe this is a bug in the VC parser ...

Comment 5

[Ben Turner (not reading bugmail, use the needinfo flag!)]

That seems to have worked, yeah.

Comment 6

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Wonderful.