On Thu, 27 Oct 2022 05:24:33 GMT, Ioi Lam <ik...@openjdk.org> wrote:
>> Improve the handling of the
>> `java.lang.invoke.MethodHandle.TRACE_METHOD_LINKAGE` property to print out
>> the full graph of MethodHandles that are used at a CallSite. This helps us
>> understand how invokedynamic call sites are resolved. For example:
>>
>>
>> public class StrConcat {
>> static String hello = "Hello";
>> static String world = "World";
>> public static void main(String args[]) {
>> System.out.println(hello + world);
>> System.out.println(hello + "World");
>> }
>> }
>>
>> $ java -Djava.lang.invoke.MethodHandle.TRACE_METHOD_LINKAGE=true -cp .
>> StrConcat
>> linkCallSite StrConcat.main(StrConcat.java:5)
>> java.lang.invoke.StringConcatFactory.makeConcatWithConstants(Lookup,String,MethodType,String,Object[])CallSite/invokeStatic
>> makeConcatWithConstants(String,String)String/BSA1=
>> linkMethod
>> java.lang.invoke.MethodHandle.invokeExact(Lookup,String,MethodType,String,Object[])CallSite/5
>> linkMethod =>
>> java.lang.invoke.Invokers$Holder.invokeExact_MT(Object,Object,Object,Object,Object,Object,Object)Object/invokeStatic
>> + (Lookup,String,MethodType,String,Object[])CallSite
>> linkCallSite target class => java.lang.invoke.BoundMethodHandle$Species_L
>> linkCallSite target => (String,String)String :
>> BMH.reinvoke000_LLL_L=Lambda(a0:L/SpeciesData[L => Species_L],a1:L,a2:L)=>{
>> t3:L=Species_L.argL0(a0:L);
>> t4:L=MethodHandle.invokeBasic(t3:L,a1:L,a2:L);t4:L}
>> & BMH=[
>> 0: MethodHandle = {(Object,Object)String :
>> DMH.invokeStatic000_LLL_L=Lambda(a0:L,a1:L,a2:L)=>{
>> t3:L=DirectMethodHandle.internalMemberName(a0:L);
>> t4:L=MethodHandle.linkToStatic(a1:L,a2:L,t3:L);t4:L}
>> &
>> DMH.MN=java.lang.StringConcatHelper.simpleConcat(Object,Object)String/invokeStatic
>> }
>> ]
>> linkCallSite linkage =>
>> java.lang.invoke.Invokers$Holder.linkToTargetMethod(Object,Object,Object)Object/invokeStatic
>> + MethodHandle(String,String)String
>> HelloWorld
>> linkCallSite StrConcat.main(StrConcat.java:6)
>> java.lang.invoke.StringConcatFactory.makeConcatWithConstants(Lookup,String,MethodType,String,Object[])CallSite/invokeStatic
>> makeConcatWithConstants(String)String/BSA1=World
>> linkCallSite target class => java.lang.invoke.BoundMethodHandle$Species_LL
>> linkCallSite target => (String)String :
>> invoke000_LL_L=Lambda(a0:L/SpeciesData[LL =>
>> BoundMethodHandle$Species_LL],a1:L)=>{
>> t2:L=BoundMethodHandle$Species_LL.argL1(a0:L);
>> t3:L=BoundMethodHandle$Species_LL.argL0(a0:L);
>> t4:L=MethodHandle.invokeBasic(t3:L,a1:L,t2:L);t4:L}
>> & BMH=[
>> 0: MethodHandle = {(Object,Object)String :
>> DMH.invokeStatic000_LLL_L=Lambda(a0:L,a1:L,a2:L)=>{
>> t3:L=DirectMethodHandle.internalMemberName(a0:L);
>> t4:L=MethodHandle.linkToStatic(a1:L,a2:L,t3:L);t4:L}
>> &
>> DMH.MN=java.lang.StringConcatHelper.simpleConcat(Object,Object)String/invokeStatic
>> }
>> 1: ( World )
>> ]
>> linkCallSite linkage =>
>> java.lang.invoke.Invokers$Holder.linkToTargetMethod(Object,Object)Object/invokeStatic
>> + MethodHandle(String)String
>> HelloWorld
>>
>>
>> More complex examples are in the JBS bug report
>> - https://bugs.openjdk.org/secure/attachment/101202/eclipse-ide-log.txt
>> - https://bugs.openjdk.org/secure/attachment/101203/lambda-expression.txt
>> -
>> https://bugs.openjdk.org/secure/attachment/101205/pattern-matching-switch.txt
>> - https://bugs.openjdk.org/secure/attachment/101204/str-concat.txt
>
> Ioi Lam has updated the pull request with a new target base due to a merge or
> a rebase. The incremental webrev excludes the unrelated changes brought in by
> the merge/rebase. The pull request contains six additional commits since the
> last revision:
>
> - Merge branch 'master' into 8295537-trace-jli-dynamic-call-sites
> - Use Thread::getStackTrace() to find the caller's line number, etc
> - @JornVernee comments
> - also print the BSM
> - cleaned up code; added comments; avoid using indy inside TRACE_CALLSITE;
> avoid interleaving output
> - 8295537: Debug tracing for resolved dynamic call sites
Marked as reviewed by mchung (Reviewer).
-------------
PR: https://git.openjdk.org/jdk/pull/10842
