[foreign] RFR: 8223489: _Atomic types can cause StackOverflowError

[Henry Jen]

Hi,

Please review a webrev[1] that detects an atomic type to get the correct layout for the type.

A proper solution would be have libclang expose the atomic types, so we don’t need to add the ugly hacks in Java to find the type. A patch is submitted[2] to clang project and hopefully this can be fixed in future release.

Before that happens, we have our java clang binding trying do that work by:
- Put together a temporary header file with C11 types to parse, so we can get this builtin-types.
- During the cursor-traversing, we will add in extra types declared in the header files
- For an atomic type, we use the type string to get the underlying type.

Note that an atomic type is always a builtin type without valid declaration cursor, so we cannot get the translation unit the type actually defined in, so we are doing a global search. Since jextract will only created one translation unit, the hack should work just fine without much pollution.

Cheers,
Henry

[1] http://cr.openjdk.java.net/~henryjen/panama/8223489/0/webrev/
[2] https://reviews.llvm.org/D61716