RFR: 8295537: Debug tracing for resolved java.lang.invoke.CallSite [v2]

[Ioi Lam]

> I've added a `java.lang.invoke.MethodHandle.TRACE_CALLSITE` property to show 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_CALLSITE=true -cp . StrConcat
> ======== CallSite: StrConcat.main(StrConcat.java:5)
> BSM = java.base/java.lang.invoke.StringConcatFactory.makeConcatWithConstants(StringConcatFactory.java:354)
> target class = java.lang.invoke.BoundMethodHandle$Species_L
> target = (String,String)String : BMH.reinvoke=Lambda(a0:L/SpeciesData[L => Species_L],a1:L,a2:L)=>{
>     t3:L=Species_L.argL0(a0:L);
>     t4:L=MethodHandle.invokeBasic(t3:L,a1:L,a2:L);t4:L}
> & BMH=[
>   0: MethodHandle = {(Object,Object)String : DMH.invokeStatic=Lambda(a0:L,a1:L,a2:L)=>{
>         t3:L=DirectMethodHandle.internalMemberName(a0:L);
>         t4:L=MethodHandle.linkToStatic(a1:L,a2:L,t3:L);t4:L}
>     & DMH.MN=java.lang.StringConcatHelper.simpleConcat(Object,Object)String/invokeStatic
>   }
> ]
> HelloWorld
> ======== CallSite: StrConcat.main(StrConcat.java:6)
> BSM = java.base/java.lang.invoke.StringConcatFactory.makeConcatWithConstants(StringConcatFactory.java:354)
> target class = java.lang.invoke.BoundMethodHandle$Species_LL
> target = (String)String : invoke=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.invokeStatic=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 )
> ]
> HelloWorld
> 
> 
> More complex examples are in the JBS bug report
> - https://bugs.openjdk.org/secure/attachment/101170/eclipse-ide-log.txt
> - https://bugs.openjdk.org/secure/attachment/101168/lambda-expression.txt
> - https://bugs.openjdk.org/secure/attachment/101174/pattern-matching-switch.txt
> - https://bugs.openjdk.org/secure/attachment/101169/str-concat.txt

Ioi Lam has updated the pull request incrementally with one additional commit since the last revision:

  @JornVernee comments

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/10842/files
  - new: https://git.openjdk.org/jdk/pull/10842/files/b09baf43..94d7a900

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10842&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10842&range=00-01

  Stats: 106 lines in 4 files changed: 29 ins; 73 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/10842.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10842/head:pull/10842

PR: https://git.openjdk.org/jdk/pull/10842