[all-commits] [llvm/llvm-project] 5eb44d: Make _LIBUNWIND_SUPPORT_FRAME_APIS a build-time op...

[Sterling-Augustine via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5eb44df1b64dbd1a86b099128092a7fd2001c0ba
      https://github.com/llvm/llvm-project/commit/5eb44df1b64dbd1a86b099128092a7fd2001c0ba
  Author: Sterling Augustine <saugustine at google.com>
  Date:   2023-08-23 (Wed, 23 Aug 2023)

  Changed paths:
    M libunwind/CMakeLists.txt
    M libunwind/src/config.h

  Log Message:
  -----------
  Make _LIBUNWIND_SUPPORT_FRAME_APIS a build-time option

Previously this was based on target architecture, but
that makes very little sense--frame API availability is generally
for libgcc compatibility and that is dependent on runtime
needs rather than target architecture.

Default this to on, so as not to remove the apis from
environments that already have them.

The functions this macro protects are stubs for libgcc-compatibility.
Today, libunwind as a drop-in replacement for libgcc_eh links on x86,
x86_64, and powerpc, but not aarch64, which doesn't really make
sense. As there is nothing architecture specific about these, they
should be provided everywhere or nowhere.

The target-specific protection goes all the way back to the original
code contribution in 312fcd0e1cf14482b2ae8eee8234541dcc3bc2c4 from
2013, so the original reason is lost to history, and probably not
relevant today.

Differential Revision: https://reviews.llvm.org/D158011