and soft-float for both rv32 and rv64.

Differential Revision: https://reviews.llvm.org/D80690

This change adds support for the dwarf PC register column in arm64, allowing
CFI directives to make use of it.

As of the last revision of the DWARF for ARM 64-bit architecture[0], the pc
register has been added as a valir register, with number 32.

This allows libunwinder to restore both pc and lr, which is useful
for stack switches and signal contexts.

[0]:
https://github.com/ARM-software/abi-aa/blob/f52e1ad3f81254497a83578dc102f6aac89e52d0/aadwarf64/aadwarf64.rst

Reviewed By: phosek, #libunwind

Differential Revision: https://reviews.llvm.org/D96901

Modify libunwind to support SjLj exception handling routines for VE.
In order to do that, we need to implement not only SjLj exception
handling routines but also a Registers_ve class.  This implementation
of Registers_ve is incomplete.  We will work on it later when we need
backtrace in libunwind.

Reviewed By: #libunwind, compnerd

Differential Revision: https://reviews.llvm.org/D94591

An AArch64 sigreturn trampoline frame can't currently be described
in a DWARF .eh_frame section, because the AArch64 DWARF spec currently
doesn't define a constant for the PC register. (PC and LR may need to
be restored to different values.)

Instead, use the same technique as libgcc or github.com/libunwind and
detect the sigreturn frame by looking for the sigreturn instructions:

    mov x8, #0x8b
    svc #0x0

If a sigreturn frame is detected, libunwind restores all the GPRs by
assuming that sp points at an rt_sigframe Linux kernel struct. This
behavior is a fallback mode that is only used if there is no ordinary
unwind info for sigreturn.

If libunwind can't find unwind info for a PC, it assumes that the PC is
readable, and would crash if it isn't. This could happen if:
 - The PC points at a function compiled without unwind info, and which
   is part of an execute-only mapping (e.g. using -Wl,--execute-only).
 - The PC is invalid and happens to point to unreadable or unmapped
   memory.

In the tests, ignore a failed dladdr call so that the tests can run on
user-mode qemu for AArch64, which uses a stack-allocated trampoline
instead of a vDSO.

Reviewed By: danielkiss, compnerd, #libunwind

Differential Revision: https://reviews.llvm.org/D90898

When built in SEH mode, UnwindCursor contains a CONTEXT struct,
which is aligned to 16 bytes in most configurations, causing the
whole UnwindCursor object to have 16 byte alignment.

This fixes backtraces using _Unwind_Backtrace on x86_64 mingw,
where an unw_cursor_t allocated on the stack was misaligned before.

This is an ABI break for this struct for this configuration, but very
few callers call libunwind directly (and even fewer directly allocate
an unw_cursor_t anyway).

Differential Revision: https://reviews.llvm.org/D86102

This patch renames `__personality_routine` to `_Unwind_Personality_Fn`
in `unwind.h`. Both `unwind.h` from clang and GCC headers use this name
instead of `__personality_routine`. With this patch one is also able to
build libc++abi with libunwind support on Windows.

Patch by Markus Böck!

Summary:
Add unwinding support for 64-bit RISC-V.

This is from the FreeBSD implementation with the following minor
changes:

- Renamed and renumbered DWARF registers to match the RISC-V ABI [1]
- Use the ABI mneumonics in getRegisterName() instead of the exact
   register names
- Include checks for __riscv_xlen == 64 to facilitate adding the 32-bit
   ABI in the future.

[1] https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md

Patch by Mitchell Horne (mhorne)

Reviewers: lenary, luismarques, compnerd, phosek

Reviewed By: lenary, luismarques

Subscribers: arichardson, sameer.abuasal, abidh, asb, aprantl, krytarowski, simoncook, kito-cheng, christof, shiva0217, rogfer01, rkruppe, PkmX, psnobl, benna, lenary, s.egerton, luismarques, emaste, cfe-commits

Differential Revision: https://reviews.llvm.org/D68362

Those are now hosted on GitHub.

rdar://problem/36557462

llvm-svn: 358191

This is unfinished, unused and incomplete. This could be brought back in
the future if there's a desire to build a more complete implementation,
but at the moment it's just bitrotting.

Differential Revision: https://reviews.llvm.org/D57252

llvm-svn: 352965