RFR: 8354675: Create separate image builder for hermetic

[Severin Gehwolf]

On Thu, 10 Apr 2025 16:13:47 GMT, Severin Gehwolf <sgehwolf at openjdk.org> wrote:

> This is a start of a simple refactoring for moving hermetic handling into dedicated implementation classes. In this case I cover `ImageBuilder` and `ExecutableImage`. A similar change should be done for `ImageFileCreator` but that's for another PR.
> 
> @jianglizhou Please take a look. Thanks!
> 
> While at it I've observed the following:
> 
> 1. `<hermetic-image-file> --list-modules` doesn't seem to work. Shows [1] for me.
> 2. `strip -g <hermetic-image-file>` will destroy the image. Looks like [2]. Probably a drawback for tucking on the offset after the modules file? We might want to consider building in debuginfo handling into `jlink` itself. Like the `--strip-native-debug-symbols` plugin does (but doesn't work for hermetic, yet).
> 
> Thoughts?
> 
> [1]
> 
> $ ./demo-image -m mod.example/com.example.demo.Main
> [0.017s][warning][cds] Failed to open shared archive file (Not a directory)
> Hi
> $
> ./demo-image --list-modules
> [0.020s][warning][cds] Failed to open shared archive file (Not a directory)
> Exception in thread "main" java.lang.InternalError: Unable to detect the run-time image
> 	at java.base/jdk.internal.module.SystemModuleFinders.ofSystem(Unknown Source)
> 	at java.base/java.lang.module.ModuleFinder.ofSystem(Unknown Source)
> 	at java.base/jdk.internal.module.ModuleBootstrap.unlimitedFinder(Unknown Source)
> 	at java.base/jdk.internal.module.ModuleBootstrap.limitedFinder(Unknown Source)
> 	at java.base/sun.launcher.LauncherHelper.listModules(Unknown Source)
> 
> 
> [2] This is a build with `--with-native-debug-symbols=internal` (fastdebug)
> 
> $ ll -lh ./demo-image 
> -rwxr-xr-x. 1 sgehwolf sgehwolf 909M Apr 10 17:36 ./demo-image
> $ strip -g ./demo-image 
> $ ll -lh ./demo-image 
> -rwxr-xr-x. 1 sgehwolf sgehwolf 50M Apr 10 18:07 ./demo-image
> $ ./demo-image -m mod.example/com.example.demo.Main
> Error occurred during initialization of VM
> Failed setting boot class path.

> > > --list-modules doesn't seem to work. Shows [1] for me.
> > > strip -g  will destroy the image. Looks like [2]. Probably a drawback for tucking on the offset after the modules file? We might want to consider building in debuginfo handling into jlink itself. Like the --strip-native-debug-symbols plugin does (but doesn't work for hermetic, yet).
> > > Thoughts?
> > > [1]
> > > $ ./demo-image -m mod.example/com.example.demo.Main
> > > [0.017s][warning][cds] Failed to open shared archive file (Not a directory)
> > > Hi
> > > $
> > > ./demo-image --list-modules
> > > [0.020s][warning][cds] Failed to open shared archive file (Not a directory)
> > > Exception in thread "main" java.lang.InternalError: Unable to detect the run-time image
> > > at java.base/jdk.internal.module.SystemModuleFinders.ofSystem(Unknown Source)
> > > at java.base/java.lang.module.ModuleFinder.ofSystem(Unknown Source)
> > > at java.base/jdk.internal.module.ModuleBootstrap.unlimitedFinder(Unknown Source)
> > > at java.base/jdk.internal.module.ModuleBootstrap.limitedFinder(Unknown Source)
> > > at java.base/sun.launcher.LauncherHelper.listModules(Unknown Source)
> > 
> > 
> > Looks like a case that has not yet been handled, but I'll test with our internal prototype to check if `--list-modules` also fails and if it's due to any patches that I missed to port for the branch. @jerboaa Could you file a bug for this? Thanks
> 
> @jerboaa, the issue exists in our current internal prototype also. The problem is due to the missing hermetic support in `SystemModuleFinders.ofSystem()`. Checking the logged bugs, I realized that I had noticed this issue while making the change for hermetic jimage (the modules) supported `.*(default|exempt)_.*policy` last March. It remained as unresolved.
> 
> I just pushed the following commit, which should resolve the issue:
> 
> [de66378](https://github.com/openjdk/leyden/commit/de66378768dd6ac084b6cabc48cc986a283def36)

OK, thanks!

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PR Comment: https://git.openjdk.org/leyden/pull/55#issuecomment-2805506655