On 27/04/2023 07.53, Paul Gevers wrote:
Control: tags -1 moreinfo Hi Andreas, On 20-04-2023 19:16, Andreas Beckmann wrote:Looks like I forgot to merge the -fvisibility=hidden changes from src:spirv-llvm-translator-14 (and the corresponding removal of 4500+ useless C++ symbols from the .symbols file) into src:spirv-llvm-translator-15. Just noticed while preparing -16 for experimental.I'm a bit paranoid and not very well versed on C++ symbols. Can you please summarize (or point to a short explanation elsewhere on the internet) why they are useless and can be safely *removed*? In other words, why is it not possible that something already uses those symbols? (I recall rra had a good explanation why symbol files were rather useless for C++, but from memory that feels not exactly the same)
The symbols I want to get rid of with -fvisibiity=hidden mostly stem from template instantiations of the standard template library and llvm. Some parts of them usually change between compiler versions since internal implementation details of the template libraries change - this symbol disappearance is ignored and does not result in bumped sonames or package names. Even different optimization levels can influence the generated symbols (by (not) inlining some bits). Also all potential users of these symbols should already have them on their own since the templates get instantiated during compilation (unless they do very special stuff), so the "external" ones won't be considered.
Some further reading on hidden visibility: https://gcc.gnu.org/wiki/Visibility AndreasPS: for pocl I managed to get visibility=hidden support upstream and enabled by default