RFR: 8271461: CompileCommand support for hidden class methods

[David Holmes]

On Thu, 29 Jul 2021 07:50:59 GMT, Jie Fu <jiefu at openjdk.org> wrote:

> Hi all,
> 
> We'd like to improve the CompileCommand to support hidden class methods, which is helpful for debugging and perfmance analysis.
> 
> Current implementation of CompileCommand doesn't work for hidden class methods.
> For example, if you run with `java -Xcomp -Xbatch -XX:+PrintCompilation`
> The following hidden class methods were compiled:
> 
>    5317 1573    b  3       java.util.ResourceBundle$$Lambda$1/0x00000008010413c8::run (8 bytes)
>    5318 1574    b  4       java.util.ResourceBundle$$Lambda$1/0x00000008010413c8::run (8 bytes)
>    6735 1938    b  3       java.util.ResourceBundle$ResourceBundleProviderHelper$$Lambda$2/0x0000000801041e80::run (12 bytes)
>    6736 1939    b  4       java.util.ResourceBundle$ResourceBundleProviderHelper$$Lambda$2/0x0000000801041e80::run (12 bytes)
>    7060 2029    b  3       java.util.ResourceBundle$ResourceBundleProviderHelper$$Lambda$58/0x800000060::run (8 bytes)
>    7061 2030    b  4       java.util.ResourceBundle$ResourceBundleProviderHelper$$Lambda$58/0x800000060::run (8 bytes)
>    7688 2153    b  3       java.util.ResourceBundle$ResourceBundleProviderHelper$$Lambda$4/0x0000000801043218::run (16 bytes)
>    7688 2154    b  4       java.util.ResourceBundle$ResourceBundleProviderHelper$$Lambda$4/0x0000000801043218::run (16 bytes)
> 
> 
> Then people may want to exclude the compilation of `java.util.ResourceBundle$$Lambda$1/0x00000008010413c8::run` like this
> 
> -XX:CompileCommand=exclude,'java.util.ResourceBundle$$Lambda$1/0x00000008010413c8::run'
> 
> 
> But unfortunately, it doesn't work.
> 
> CompileCommand: An error occurred during parsing
> Error: Method pattern uses '/' together with '::'
> Line: 'exclude,java.util.ResourceBundle$$Lambda$1/0x00000008010413c8::run'
> 
> Usage: '-XX:CompileCommand=<option>,<method pattern>' - to set boolean option to true
> Usage: '-XX:CompileCommand=<option>,<method pattern>,<value>'
> Use:   '-XX:CompileCommand=help' for more information and to list all option.
> 
> 
> The failing reason is that the name of `java.util.ResourceBundle$$Lambda$1/0x00000008010413c8::run` is actually `java.util.ResourceBundle$$Lambda$1+0x00000008010413c8::run` in the VM.
> But "+" had been replaced with "/" when it was printed by PrintCompilation [1].
> 
> So for a hidden class method, "/" should be replaced with "+" to make CompileCommand work.
> 
> Thanks.
> Best regards,
> Jie
> 
> 
> [1] https://github.com/openjdk/jdk/blob/master/src/hotspot/share/oops/klass.cpp#L685

src/hotspot/share/compiler/methodMatcher.cpp line 125:

> 123:           // There may be false positive cases, but all of them are harmless and won't make anything worse.
> 124:           char next = *(lp + 1);
> 125:           if (('0' <= next && next <= '9') || next == '*') {

Please use isdigit(next)

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

PR: https://git.openjdk.java.net/jdk/pull/4926