The History of nortti and noeh on AIX

[Tyler Steele]

Hi all,

I was recently asked [1] why we include -qnoeh [2] and -qnoftti [3] with the build. It looks like it's been in the project since at least jdk9 [4], but I suspect that might not be the true origin of the flags.

Reading the descriptions for the flags makes me suspect that these were added to improve performance "For improved runtime performance, suppress RTTI information generation with the -qnortti setting." [2] and possibly to reduce code bloat "If your program does not use C++ structured exception handling, you can compile with -qnoeh to prevent generation of code that is not needed by your application." [3]. But these are just guesses. Any chance that anyone out there knows/remembers why these were added?

Tyler

[1] https://github.com/adoptium/adoptium-support/issues/824#issuecomment-1599049333
[2] https://www.ibm.com/docs/en/xl-c-and-cpp-aix/16.1?topic=descriptions-qrtti-qnortti-fno-rtti-c-only
[3] https://www.ibm.com/docs/en/xl-c-and-cpp-aix/16.1?topic=descriptions-qeh-fexceptions-c-only#opt_eh
[4] https://github.com/openjdk/jdk/commit/e709aa268df64b2dc000433a1d9621a2fb0940f0
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