clang_getCString returns garbage in lwjgl-llvm module

[jolby]

Environment

• LWJGL version: 3.2.2
• LWJGL build #: 10
• Java version: OpenJDK 64-Bit Server VM v11.0.4+11-post-Debian-1bpo91 by Debian
• Platform: Linux x86_64
• Module: llvm

Description

The static method clang_getCString in ClangIndex in the llvm module returns garbage characters. I think that may because native clang_getCString expects a CXString struct passed as value, but lwjgl passes a Pointer/long address?? I'm not sure about that and I'm new to lwjgl.

I have attached a minimum test case illustrating the problem.
CXStringTest.java.txt

Note that the test case also shows you can properly get the String by getting the address of the first member of the CXString struct:

CXString cxstr = CXString.callocStack(stack);
//...
// VVVV--- This works
String cstr = memUTF8Safe(memGetAddress(cxstr.address()));

[Spasi]

Thank you @jolby!

The Clang API is heavily used in the Template Extraction tool in LWJGL, but I never tested it on Linux. On Windows, >64bit structs are passed by pointer, so the bindings worked there correctly by accident.