RFR: 8146001: Remove support for command line options from JVMCI

[Doug Simon]

> On 04 Jan 2016, at 18:41, Christian Thalinger <christian.thalinger at oracle.com> wrote:
> 
>> 
>> On Jan 4, 2016, at 7:19 AM, Christian Thalinger <christian.thalinger at oracle.com> wrote:
>> 
>>> 
>>> On Jan 4, 2016, at 7:16 AM, Christian Thalinger <christian.thalinger at oracle.com> wrote:
>>> 
>>>> 
>>>> On Dec 22, 2015, at 4:50 AM, Doug Simon <doug.simon at oracle.com> wrote:
>>>> 
>>>> The effort of maintaining JVMCI across different JDK versions (including a potential backport to JDK7) is reduced by making JVMCI as small as possible. The support for command line options in JVMCI (based around the @Option annotation) is a good candidate for removal: 
>>>> 
>>>> 1. It’s almost entirely implemented on top of system properties and so can be made to work without VM support. 
>>>> 2. JVMCI itself only currently uses 3 options which can be replaced with usage of sun.misc.VM.getSavedProperty(). The latter ensures application code can’t override JVMCI properties set on the command line.
>>>> 
>>>> This change removes the JVMCI command line option support.
>>>> 
>>>> https://bugs.openjdk.java.net/browse/JDK-8146001
>>>> http://cr.openjdk.java.net/~dnsimon/8146001/
>>> 
>>> +    private static final boolean TrustFinalDefaultFields = HotSpotJVMCIRuntime.getBooleanProperty(TrustFinalDefaultFieldsProperty, true);
>>> 
>>> +    private static final boolean ImplicitStableValues = HotSpotJVMCIRuntime.getBooleanProperty("jvmci.ImplicitStableValues", true);
>>> 
>>> We should either use the jvmci. prefix or not.
>> 
>> Sorry, I was reading the patch wrong.  Of course both use the jvmci. prefix.
> 
> I think we should prefix the property name in getBooleanProperty:
> 
> +    public static boolean getBooleanProperty(String name, boolean def) {
> +        String value = VM.getSavedProperty("jvmci." + name);

Ok, sounds reasonable.

> 
> and I put UseProfilingInformation back:
> 
> diff -r 0fcfe4b07f7e src/jdk.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotResolvedJavaMethodImpl.java
> --- a/src/jdk.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotResolvedJavaMethodImpl.java	Tue Dec 29 18:30:51 2015 +0100
> +++ b/src/jdk.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotResolvedJavaMethodImpl.java	Mon Jan 04 07:40:46 2016 -1000
> @@ -24,7 +24,6 @@ package jdk.vm.ci.hotspot;
>  
>  import static jdk.vm.ci.hotspot.CompilerToVM.compilerToVM;
>  import static jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.runtime;
> -import static jdk.vm.ci.hotspot.HotSpotResolvedJavaMethod.Options.UseProfilingInformation;
>  import static jdk.vm.ci.hotspot.HotSpotVMConfig.config;
>  import static jdk.vm.ci.hotspot.UnsafeAccess.UNSAFE;
>  
> @@ -65,6 +64,11 @@ import jdk.vm.ci.meta.TriState;
>  final class HotSpotResolvedJavaMethodImpl extends HotSpotMethod implements HotSpotResolvedJavaMethod, HotSpotProxified, MetaspaceWrapperObject {
>  
>      /**
> +     * Whether to use profiling information.
> +     */
> +    private static final boolean UseProfilingInformation = HotSpotJVMCIRuntime.getBooleanProperty("UseProfilingInformation", true);
> +
> +    /**
>       * Reference to metaspace Method object.
>       */
>      private final long metaspaceMethod;
> @@ -424,7 +428,7 @@ final class HotSpotResolvedJavaMethodImp
>      public ProfilingInfo getProfilingInfo(boolean includeNormal, boolean includeOSR) {
>          ProfilingInfo info;
>  
> -        if (UseProfilingInformation.getValue() && methodData == null) {
> +        if (UseProfilingInformation && methodData == null) {
>              long metaspaceMethodData = UNSAFE.getAddress(metaspaceMethod + config().methodDataOffset);
>              if (metaspaceMethodData != 0) {
>                  methodData = new HotSpotMethodData(metaspaceMethodData, this);

JVMCI should unconditionally return available profiling information. It's up to the compiler whether or not to use it. For example, this is now compilation local in Graal:

http://hg.openjdk.java.net/graal/graal-compiler/rev/f35e653aa876#l16.16

-Doug