RFR: 7903783: Jextract should tolerate more CPP constructs when running with xc++

[Jorn Vernee]

On Thu, 1 Aug 2024 12:40:35 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

>> This PR fixes a bunch of issues with trying to run jextract in CPP mode, using a `compile_flags.txt` file containing the `-xc++` flag.
>> 
>> I've found at least three issues:
>> * extern C clauses are not recursively scanned
>> * the first time we see a cursor with language != C, we stop with an exception (instead of skipping)
>> * typing of enum constant is different in C++ and causes infinite recursion 
>> 
>> These issues were preventing jextract to work with real world libraries (I tested OpenGL) when `-xc++` was specified.
>> 
>> Now jextract will try to parse as much as possible. Unrecognized constructs/languages will be skipped and a diagnostic will be reported by the log.
>
> src/main/java/org/openjdk/jextract/impl/TreeMaker.java line 131:
> 
>> 129:     private boolean isAllowedCXXDecl(Cursor cursor) {
>> 130:         return switch (cursor.kind()) {
>> 131:             case StaticAssert, StructDecl, UnionDecl -> true;
> 
> When in C++ mode, both structs and unions are reported to have language C++ (understandable, since they can also contain more members, such as methods). So we need to add a list of the constructs we like, regardless of the language.

Why is `StaticAssert` here as well?

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PR Review Comment: https://git.openjdk.org/jextract/pull/256#discussion_r1752284626