RFR: 8317611: Add a tool like jdeprscan to find usage of restricted methods

[Maurizio Cimadamore]

On Tue, 18 Jun 2024 16:30:37 GMT, Jorn Vernee <jvernee at openjdk.org> wrote:

> This PR adds a new JDK tool, called `jnativescan`, that can be used to find code that accesses native functionality. Currently this includes `native` method declarations, and methods marked with `@Restricted`.
> 
> The tool accepts a list of class path and module path entries through `--class-path` and `--module-path`, and a set of root modules through `--add-modules`, as well as an optional target release with `--release`.
> 
> The default mode is for the tool to report all uses of `@Restricted` methods, and `native` method declaration in a tree-like structure:
> 
> 
> app.jar (ALL-UNNAMED):
>   main.Main:
>     main.Main::main(String[])void references restricted methods:
>       java.lang.foreign.MemorySegment::reinterpret(long)MemorySegment
>     main.Main::m()void is a native method declaration
> 
> 
> The `--print-native-access` option can be used print out all the module names of modules doing native access in a comma separated list. For class path code, this will print out `ALL-UNNAMED`.
> 
> Testing: 
> - `langtools_jnativescan` tests.
> - Running the tool over jextract's libclang bindings, which use the FFM API, and thus has a lot of references to `@Restricted` methods.
> - tier 1-3

src/jdk.jdeps/share/classes/com/sun/tools/jnativescan/Main.java line 125:

> 123:         if (optionSet.has(helpOpt)) {
> 124:             out.println("""
> 125:                 The jnativescan tool can be used to find methods that may access native functionality when

Suggestion:

                The jnativescan tool can be used to find methods that may access native functionalities when

src/jdk.jdeps/share/classes/com/sun/tools/jnativescan/Main.java line 126:

> 124:             out.println("""
> 125:                 The jnativescan tool can be used to find methods that may access native functionality when
> 126:                 run. This includes methods that call restricted methods, and 'native' method declarations.

I think it would be more readable if we said "This includes restricted method calls and `native` method declarations`. The way it is now it seems (for some weird subjective reason) that the sentence is saying "methods ... that call ... native method declarations" :-)

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PR Review Comment: https://git.openjdk.org/jdk/pull/19774#discussion_r1646530805
PR Review Comment: https://git.openjdk.org/jdk/pull/19774#discussion_r1646531845