These were already compiled for some time on aarch64 and riscv, by
including lib/libcompiler_rt/Makefile.inc, but never exported in the
shared library. Since gcc exports these under version GCC_4.6.0, we do
the same.
This review should replace D11482 for now. For e.g. amd64 more work is
still to be done, as compiler-rt does not seem to support 128 bit long
double math for that architecture.
Reviewed by: cem
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D28690
In original GNU libgcc, _Unwind_Backtrace is published with GCC_3.3 version
for all architectures but ARM. For ARM should be publishes with GCC_4.3.0
version. This was originally omitted in r255095, fixed in r318024 and omitted
aging in LLVM libunwind implementation in r354347.
For ARM _Unwind_Backtrace should be published as default with GCC_4.3.0
version , (because this is right original version) and again as
normal(not-default) with GCC_3.3 version (to maintain ABI compatibility
compiled/linked with wrong pre r318024 libgcc)
PR: 233664
GCC's libgcc exports a few ARM-specific symbols for ARM EABI, AEABI, or
EHABI or whatever it's called. Export the same ones from LLVM-libunwind's
libgcc_s, on ARM. As part of this, convert libgcc_s from a direct
Version.map to one constructed from component Symbol.map files. This allows
the ARM-specific Symbol.map to be included only on ARM.
Fix ARM-only oddities in struct name/aliases in LLVM-libunwind to match
non-ARM definitions and ARM-specific expectations in libcxxrt /
libcompiler_rt.
No functional change intended for non-ARM architectures.
This commit does not actually flip the switch for ARM defaults from libgcc
to llvm-libunwind, but makes it possible (to compile, anyway).
