The perl context is passed around as pTHX and aTHX as a C param. Only legacy/abandoned XS code and the C Lib emulators in Perl call Perl_get_context() nowadays. Not using PERL_NO_GET_CONTEXT for all XS code in the last 10 years is a sin. Then again, most CPAN authors don't care (I'm staring at you Win32:: namespace).
Re^12: Perl 5 Optimizing Compiler, Part 4: LLVM Backend?
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