RFR: 8074895: os::getenv is inadequate

[David Holmes]

Okay I managed to fix this with:

--- old/src/share/vm/utilities/growableArray.hpp	2015-03-26 
02:34:35.715892476 -0400
+++ new/src/share/vm/utilities/growableArray.hpp	2015-03-26 
02:34:34.663833288 -0400
@@ -168,6 +168,8 @@
    GrowableArray(int initial_size, bool C_heap = false, MEMFLAGS F = 
mtInternal)
      : GenericGrowableArray(initial_size, 0, C_heap, F) {
      _data = (E*)raw_allocate(sizeof(E));
+// Needed for Visual Studio 2012 and older
+#pragma warning(suppress: 4345)
      for (int i = 0; i < _max; i++) ::new ((void*)&_data[i]) E();
    }

@@ -385,6 +387,8 @@
      E* newData = (E*)raw_allocate(sizeof(E));
      int i = 0;
      for (     ; i < _len; i++) ::new ((void*)&newData[i]) E(_data[i]);
+// Needed for Visual Studio 2012 and older
+#pragma warning(suppress: 4345)
      for (     ; i < _max; i++) ::new ((void*)&newData[i]) E();
      for (i = 0; i < old_max; i++) _data[i].~E();
      if (on_C_heap() && _data != NULL) {

So unless someone finds this totally objectionable it is what I propose 
to go with. Full webrev at:

http://cr.openjdk.java.net/~dholmes/8074895/webrev/

Thanks,
David

On 25/03/2015 2:24 PM, David Holmes wrote:
> 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.
>>
>>