1201628 - Define MOZ_WARN_UNUSED_RESULT in MSVC

Status: RESOLVED INVALID

(Core :: MFBT, defect)

Description

[Andrew McCreight [:mccr8]]

Apparently MSVC has had this _Check_return_ thing since MSVC 2012 [1]. I'll try and see how it works. I don't have MSVC running locally so this may get painful fast, but I'll try at least a few pushes. I've hidden this for now because it may reveal security issues in Windows-specific code.


http://stackoverflow.com/questions/4226308/msvc-equivalent-of-attribute-warn-unused-result

Comment 1

[Andrew McCreight [:mccr8]]

froydnj points out that the MSVC version requires annotating both the declaration and definition, according to that Stack Overflow answer, so this may not really be viable for us.

Comment 2

[Andrew McCreight [:mccr8]]

Attachment: Check return values on windows.

The good news is that my try run is green. The bad news is that I think it shouldn't be.

I'll try adding another intentional failure and see if that does anything.

try: https://treeherder.mozilla.org/#/jobs?repo=try&revision=26fb7e857b90

Comment 3

[Andrew McCreight [:mccr8]]

It sounds like maybe you have to run a different tool to get it to actually do something with these annotations, but I'm not entirely sure.

Comment 4

[Nathan Froyd [:froydnj]]

(In reply to Andrew McCreight [:mccr8] from comment #3)
> It sounds like maybe you have to run a different tool to get it to actually
> do something with these annotations, but I'm not entirely sure.

You need to run the compiler with -analyze.  It would be interesting to run things with -analyze as-is (I think some of the Windows headers are appropriately annotated) and see if anything turns up.

Comment 5

[Andrew McCreight [:mccr8]]

njn, I see you are on a bit of a warnings kick recently, and are messing with Windows, so I'm assuming you have a local way to build Windows. You may (or may not...) be interested in looking into seeing what this would turn up.

Comment 6

[Nicholas Nethercote [inactive]]

(In reply to Andrew McCreight [:mccr8] from comment #5)
> njn, I see you are on a bit of a warnings kick recently, and are messing
> with Windows, so I'm assuming you have a local way to build Windows.

I have a VirtualBox VM running Windows 8.1 on my Linux box. It was surprisingly easy to set up. You should totally try it sometime :)

I might take a look at this if I find some time, but I won't make any promises.

Comment 7

[Simon Giesecke [:sg] [he/him]]

MSVC is no longer supported.