RFR: 8317611: Add a tool like jdeprscan to find usage of restricted methods [v5]

[Alan Bateman]

On Thu, 20 Jun 2024 12:11:25 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
>
> Jorn Vernee has updated the pull request incrementally with one additional commit since the last revision:
> 
>   update man page header to be consisten with the others

src/jdk.jdeps/share/classes/com/sun/tools/jnativescan/JNativeScanTask.java line 113:

> 111:                     // Class-Path attribute specifies that jars that
> 112:                     // are not found are simply ignored. Do the same here
> 113:                     classPathJars.offer(otherJar);

The expansion of the class path looks right but the Class-Path attribute is awkward to deal with as its relative URI rather than a file path. More on this this later.

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PR Review Comment: https://git.openjdk.org/jdk/pull/19774#discussion_r1647929185