[PATCH] D67216: [cfi] Add flag to always generate call frame information

[John Reagan via Phabricator via llvm-commits]

JohnReagan added a comment.

Does the current code generate all the prologue cfi directives? 
Epilogue too?  The last time I checked, it did not (especially for
epilogues).

Fully asynch prologue/epilogue is one of the things that we need for
OpenVMS and will be doing that work.  We're also looking at using the
compact format instead of the CFI form (at least for routine bodies).

clang's driver already recognizes "-fasynchronous-unwind-tables" today
and maps that to "-munwind-tables" and probably should be switched to
setting your new "always-need-cfi" or simply change your name.    Either
way, I think there is an interaction between them.

>From the code in Clang.cpp

  // This is a coarse approximation of what llvm-gcc actually does, both
  // -fasynchronous-unwind-tables and -fnon-call-exceptions interact in more
  // complicated ways.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D67216/new/

https://reviews.llvm.org/D67216