RFR: 8074895: os::getenv is inadequate

[David Holmes]

On 24/03/2015 2:56 AM, Jeremy Manson wrote:
> Thanks, Kim.  This is a pretty silly warning to have break the build.
> Does anyone have a problem with PODs being default initialized?  That's
> required by the standard, so if you do, then you are Doing It Wrong.
>
> I assume it is pretty easy to turn the warning off.  I'd do it, but I
> don't have the Windows build-fu necessary.  Also, do we think it would
> require another bug?

Unless someone else can already tell me how I will try to find the 
cycles to either disable the warning in that file (if that works) else 
disable it in the build - which will need a new CR I think.

David

> I'd hate to have to change my (or any) code for this.
>
> Jeremy
>
> On Mon, Mar 23, 2015 at 8:48 AM, Kim Barrett <kim.barrett at oracle.com
> <mailto:kim.barrett at oracle.com>> wrote:
>
>     On Mar 23, 2015, at 3:45 AM, David Holmes <david.holmes at oracle.com
>     <mailto:david.holmes at oracle.com>> wrote:
>     >
>     > On 23/03/2015 4:12 PM, David Holmes wrote:
>     >> On 21/03/2015 3:32 AM, Jeremy Manson wrote:
>     >>> Argh.  Yes.  Martin told me not to get involved with Windows, but would
>     >>> I listen?  Of course not...
>     >>>
>     >>>http://cr.openjdk.java.net/~jmanson/8074895/webrev.04/
>     >>
>     >> Looks okay to me - running a test job now.
>     >
>     > <sigh> This just isn't meant to be :( It seems that:
>     >
>     > GrowableArray<JavaVMOption> options(2, true);
>     >
>     > in arguments.cpp is giving the windows compiler some grief:
>     >
>     > C:\jprt\T\P1\071814.daholme\s\hotspot\src\share\vm\utilities/growableArray.hpp(171) : error C2220: warning treated as error - no 'object' file generated
>     > C:\jprt\T\P1\071814.daholme\s\hotspot\src\share\vm\utilities/growableArray.hpp(168) : while compiling class template member function 'GrowableArray<E>::GrowableArray(int,bool,MEMFLAGS)'
>     >        with
>     >        [
>     >            E=JavaVMOption
>     >        ]
>     > C:\jprt\T\P1\071814.daholme\s\hotspot\src\share\vm\runtime\arguments.cpp(3516) : see reference to class template instantiation 'GrowableArray<E>' being compiled
>     >        with
>     >        [
>     >            E=JavaVMOption
>     >        ]
>     > C:\jprt\T\P1\071814.daholme\s\hotspot\src\share\vm\utilities/growableArray.hpp(171) : warning C4345: behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized
>     > C:\jprt\T\P1\071814.daholme\s\hotspot\src\share\vm\utilities/growableArray.hpp(388) : warning C4345: behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized
>     > C:\jprt\T\P1\071814.daholme\s\hotspot\src\share\vm\utilities/growableArray.hpp(379) : while compiling class template member function 'void GrowableArray<E>::grow(int)'
>     >        with
>     >        [
>     >            E=JavaVMOption
>     >        ]
>     >
>     > I'm guessing it doesn't like the enum as the generic arg, but don't know why given that it accepts plain int elsewhere. ???
>
>     Just suppressing this warning (unconditionally everywhere) would
>     probably make sense.
>
>     Microsoft describes it as an obsolete warning:
>
>     https://msdn.microsoft.com/en-us/library/wewb47ee.aspx
>
>     "This warning is obsolete. It is only generated in Visual Studio
>     2005 through Visual Studio 2012. It reports a behavior change from
>     the Visual C++ compiler that shipped in Visual Studio .NET when
>     initializing a POD (plain old data) object with (); the compiler
>     default-initializes the object.”
>
>     It’s too bad the JDK9 supported build platform for Windows is still
>     lagging.
>
>