fix strict aliasing problems

The (main) issue here is that char * is not allowed to alias with anyType *. With gcc-10 in Fedora this now started to cause real problems and loading stats module segfaulted.

Actually I can't see in standard (C11 6.5 par.7) that using void * is guaranteed to be correct, but at least it seems fine with gcc, and e.g. some standard functions like posix_memalign() use it in the same "dangerous" way.

EDIT: further commit deals with aliasing risks due to libuv.

added bug label

For reference, stats module in Fedora 32 currently crashes on load because of this.

TODO

• consider defaulting to -fno-strict-aliasing anyway because of libuv, especially if we see no measurable performance impact. Refs:
  • https://github.com/libuv/libuv/pull/2588/files#diff-04c6e90faac2675aa89e2176d2eec7d8
  • https://github.com/libuv/libuv/issues/1230#issuecomment-569030944

added 1 commit

• e2972723 - lib/generic/array: fix a strict aliasing problem

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There seems to be a very slight performance impact when using -fno-strict-aliasing. I've done three runs for low/heavy load (and a single run for overloaded resolver):

added 1 commit

• cad90154 - meson.build: compile with -fno-strict-aliasing

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changed title from lib/generic/array: fix a strict aliasing problem to fix a strict aliasing problems

changed the description

changed title from fix a strict aliasing problems to fix strict aliasing problems

merged

mentioned in commit a03568f9

mentioned in issue #552 (closed)