libgcc_{eh,s}: restore __*_frame_info symbols post llvm18

The upstream llvm commit 5eb44df1b64d made the addition of these GCC
compatability symbols dependent on build configuration rather than
hardcoded for amd64, i386, and powerpc. Reenable them.

Reviewed by: dim
Differential Revision: https://reviews.freebsd.org/D44877

Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

Fix DIRDEPS_BUILD for libgcc_eh

Install unwind.h into /usr/include

Install headers from LLVM's libunwind in place of the headers from
libcxxrt and allow C applications to use the library.

As part of this, remove include/unwind.h and switch libthr over to
using the installed unwind.h.

Reviewed by: dim, emaste
MFC after: 10 days
Differential Revision: https://reviews.freebsd.org/D34065

Add build system support for ASAN+UBSAN instrumentation

This adds two new options WITH_ASAN/WITH_UBSAN that can be set to
enable instrumentation of all binaries with AddressSanitizer and/or
UndefinedBehaviourSanitizer. This current patch is almost sufficient
to get a complete buildworld with sanitizer instrumentation but in
order to actually build and boot a system it depends on a few more
follow-up commits.

Reviewed By: brooks, kib, markj
Differential Revision: https://reviews.freebsd.org/D31043

After r364423, which ensures the callbacks that dl_iterate_phdr(3)
performs are protected by an exclusive lock, even for statically linked
programs, it is safe to re-enable libunwind's FrameHeaderCache, which I
temporarily disabled in r364263.

Meanwhile upstream has also used the _LIBUNWIND_USE_FRAME_HEADER_CACHE
for this purpose, so the only thing needed is to add this as a
compile-time command line flag.

While here, reformat the CFLAGS lines a little bit.

MFC after: 6 weeks
X-MFC-With: r364284, r364423

Avoid adding duplicates to SRCS/OBJS/SOBJS/POBJS

This is a change in preparation for stopping to use lorder.sh (D26044) and
instead assume that we have a linker newer than ~1990. Without lorder.sh
duplicates end up being passed to the linker when building .so files and this
can result in duplicate symbol definition errors.

There is one minor change: libcompiler_rt.a will no longer provide
gcc_personality_v0 and instead we now only have it in libgcc_eh.a/libgcc_s.so.
This matches GCC's behaviour.

Reviewed By: emaste, cem
Differential Revision: https://reviews.freebsd.org/D26042

Revert r353140: Re-add ALLOW_MIPS_SHARED_TEXTREL, sprinkle it around

arichardson has an actual fix for the same issue that this was working
around; given that we don't build with llvm today, go ahead and revert the
workaround in advance.

Move all sources from the llvm project into contrib/llvm-project.

This uses the new layout of the upstream repository, which was recently
migrated to GitHub, and converted into a "monorepo". That is, most of
the earlier separate sub-projects with their own branches and tags were
consolidated into one top-level directory, and are now branched and
tagged together.

Updating the vendor area to match this layout is next.

Re-add ALLOW_MIPS_SHARED_TEXTREL, sprinkle it around

Diff partially stolen from CheriBSD; these bits need -Wl,-z,notext in order
to build in an LLVM world. They are needed for all flavors/sizes of MIPS.
This will eventually get fixed in LLVM, but it's unclear when.

Reported by: arichardson, emaste
Differential Revision: https://reviews.freebsd.org/D21696

Rework CXXSTD setting via r345708

This change allows the user to once again override the C++ standard, restoring
high-level pre-r345708 behavior.

This also unbreaks building lib/ofed/libibnetdisc/Makefile with a non-C++11
capable compiler, e.g., g++ 4.2.1, as the library supported being built with
older C++ standards.

MFC after: 2 weeks
MFC with: r345708
Reviewed by: emaste
Reported by: jbeich
Differential Revision: https://reviews.freebsd.org/D19895 (as part of a larger change)

Standardize `-std=c++* as `CXXSTD`

CXXSTD was added as the C++ analogue to CSTD.

CXXSTD defaults to `-std=c++11` with supporting compilers; `-std=gnu++98`,
otherwise for older versions of g++.

This change standardizes the CXXSTD variable, originally added to
googletest.test.inc.mk as part of r345203.

As part of this effort, convert all `CXXFLAGS+= -std=*` calls to use `CXXSTD`.

Notes:

This value is not sanity checked in bsd.sys.mk, however, given the two
most used C++ compilers on FreeBSD (clang++ and g++) support both modes, it is
likely to work with both toolchains. This method will be refined in the future
to support more variants of C++, as not all versions of clang++ and g++ (for
instance) support C++14, C++17, etc.

Any manual appending of `-std=*` to `CXXFLAGS` should be replaced with CXXSTD.
Example:

Before this commit:
```
CXXFLAGS+= -std=c++14
```

After this commit:
```
CXXSTD= c++14
```

Reviewed by: asomers
Approved by: emaste (mentor)
MFC after: 1 month
MFC with: r345203, r345704, r345705
Relnotes: yes
Tested with: make tinderbox
Differential Revision: https://reviews.freebsd.org/D19732

Revert r345706: the third time will be the charm

When a review is closed via Phabricator it updates the patch attached to the
review. I downloaded the raw patch from Phabricator, applied it, and repeated
my mistake from r345704 by accident mixing content from D19732 and D19738.

For my own personal sanity, I will try not to mix reviews like this in the
future.

MFC after: 1 month
MFC with: r345706
Approved by: emaste (mentor, implicit)

Standardize `-std=c++* as `CXXSTD`

CXXSTD was added as the C++ analogue to CSTD.

CXXSTD defaults to `-std=c++11` with supporting compilers; `-std=gnu++98`,
otherwise for older versions of g++.

This change standardizes the CXXSTD variable, originally added to
googletest.test.inc.mk as part of r345203.

As part of this effort, convert all `CXXFLAGS+= -std=*` calls to use `CXXSTD`.

Notes:

This value is not sanity checked in bsd.sys.mk, however, given the two
most used C++ compilers on FreeBSD (clang++ and g++) support both modes, it is
likely to work with both toolchains. This method will be refined in the future
to support more variants of C++, as not all versions of clang++ and g++ (for
instance) support C++14, C++17, etc.

Any manual appending of `-std=*` to `CXXFLAGS` should be replaced with CXXSTD.
Example:

Before this commit:
```
CXXFLAGS+= -std=c++14
```

After this commit:
```
CXXSTD= c++14
```

Reviewed by: asomers
Approved by: emaste (mentor)
MFC after: 1 month
MFC with: r345203, r345704, r345705
Relnotes: yes
Tested with: make tinderbox
Differential Revision: https://reviews.freebsd.org/D19732

Revert r345704

I accidentally committed code from two reviews. I will reintroduce the code to
bsd.progs.mk as part of a separate commit from r345704.

Approved by: emaste (mentor, implicit)
MFC after: 2 months
MFC with: r345704

CXXSTD is the C++ analogue to CSTD.

CXXSTD defaults to `-std=c++11` with supporting compilers; `-std=gnu++98`,
otherwise for older versions of g++.

This change standardizes the CXXSTD variable, originally added to
googletest.test.inc.mk as part of r345203.

As part of this effort, convert all `CXXFLAGS+= -std=*` calls to use `CXXSTD`.

Notes:

This value is not sanity checked in bsd.sys.mk, however, given the two
most used C++ compilers on FreeBSD (clang++ and g++) support both modes, it is
likely to work with both toolchains. This method will be refined in the future
to support more variants of C++, as not all versions of clang++ and g++ (for
instance) support C++14, C++17, etc.

Any manual appending of `-std=*` to `CXXFLAGS` should be replaced with CXXSTD.
Example:

Before this commit:
```
CXXFLAGS+= -std=c++14
```

After this commit:
```
CXXSTD= c++14
```

Reviewed by: asomers
Approved by: emaste (mentor)
MFC after: 1 month
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D19732

Move libunwind out of contrib/llvm/projects.

Move LLVM's libunwind to its own contrib/ directory similar to other
runtime libraries like libc++ and libcxxrt.

Reviewed by: dim, emaste
Differential Revision: https://reviews.freebsd.org/D19534

In r308100, an explicit -fexceptions flag was added for the C sources
from LLVM's libunwind, which end up in libgcc_eh.a and libgcc_s.so.
This is because the unwinder needs the unwinder data for its own
functions.

However, for the C++ sources in libunwind, -fexceptions is already the
default, and this can have the side effect of generating a reference to
__gxx_personality_v0, the so-called personality function, which is
normally provided by the C++ ABI library (libcxxrt or libsupc++).

If the reference ends up in the eventual libgcc_s.so, linking any
non-C++ programs against it will fail with "undefined reference to
`__gxx_personality_v0'".

Note that at high optimization levels, the reference is usually
optimized away, which is why we have never noticed this problem before.

With clang 7.0.0 though, higher optimization levels don't help anymore,
since the addition of address-significance tables [1] in
<https://reviews.llvm.org/rL337339>. Effectively, this always causes a
reference to __gxx_personality_v0.

After discussion with the upstream author of that change, it turns out
that we should compile libunwind sources with the -fno-exceptions
-funwind-tables flags instead. This ensures unwind tables are
generated, but no references to any personality functions are emitted.

[1] https://lists.llvm.org/pipermail/llvm-dev/2018-May/123514.html

Reported by: jbeich
PR: 230399
MFC after: 1 week

DIRDEPS_BUILD: libgcc now depends on MK_LLVM_LIBUNWIND

The dependency on gnu/lib/libgcc or lib/libgcc* is determined
at 'make dirdeps' time.

Sponsored by: Dell EMC Isilon

compile libunwind c source with -fexceptions

When an exception is thrown the unwinder must unwind its own C source
(starting with _Unwind_RaiseException in UnwindLevel1.c), so it needs to
be built with unwinding data.

libgcc_eh/libgcc_s: apply hidden visibility only to static libs

Introduce lib/libgcc_eh and lib/libgcc_s for LLVM's implementation

They are not yet connected to the build, but I am adding them to allow
for easier testing, ports exp-runs, etc.

Reviewed by: ed
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D8188