Integrated: 8351958: Some compile commands should be made diagnostic

[Marc Chevalier]

On Fri, 9 May 2025 15:05:11 GMT, Marc Chevalier <mchevalier at openjdk.org> wrote:

> Error when using a `CompileCommand` that is an alias for a diagnostic option when `-XX:+UnlockDiagnosticVMOptions` is not provided.
> 
> The argument processing works this way:
> 1. Flags are parsed, setting the value accordingly. For `CompileCommand`, each option is added to a  `\n`-separated string. At this step, if a flag is diagnostic but `-XX:+UnlockDiagnosticVMOptions` is not provided, then an error message is emitted, argument parsing fails and the VM terminates. Yet, the value of `CompileCommand` is still an unparsed list of string.
> 2. Eventually, `CompileCommand` is parsed. For some of them, the value of regular flag is used as the default value, and as far as I know, it's the only mapping between `CompileCommand` and the equivalent flag. Moreover, at this point, the order of the various command line arguments is lost: it is not possible to know which `CompileCommand` comes before or after the `-XX:+UnlockDiagnosticVMOptions`.
> 
> Moreover, `CompileCommand` are parsed in the same way as compiler directives coming from a file. If we complain about diagnostic `CompileCommand`, we should also when coming from a directive file, for consistency. But then, while the relative order of `CompileCommand` and `-XX:+UnlockDiagnosticVMOptions` is lost, it simply makes no sense to compare the ordering of command line arguments and directives from a file.
> 
> So, before the difficulty and the relative lack of sense, I defaulted to ignore the ordering requirement. And by using the `CompileCommand` error reporting mechanism, we get an error that is consistent with other `CompileCommand`-parsing related errors, e.g.
> 
> CompileCommand: An error occurred during parsing
> Error: VM option 'PrintAssembly' is diagnostic and must be enabled via -XX:+UnlockDiagnosticVMOptions.
> Line: 'PrintAssembly,*::*'
> 
> 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.
> 
> CompileCommand: compileonly Test.* bool compileonly = true
> Error: Could not create the Java Virtual Machine.
> Error: A fatal exception has occurred. Program will exit.
> 
> 
> The other problem is how to identify that a `CompileCommand` is an alias for a diagnostic flag. I refrained from hardcoding the list, but there is no nice mapping stating "this is an alias for...", only the default value for some:
> https://github.com/openjdk/jdk/blob/9f9e73d5f9fcb5e926a2674c54cbbc920...

This pull request has now been integrated.

Changeset: e348aa07
Author:    Marc Chevalier <mchevalier at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/e348aa071d7d20300062de5830e74fc78143c662
Stats:     105 lines in 6 files changed: 57 ins; 16 del; 32 mod

8351958: Some compile commands should be made diagnostic

Reviewed-by: thartmann, kvn

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PR: https://git.openjdk.org/jdk/pull/25150