Merge additions of LLVM libunwind libgcc_eh and libgcc_s. This is in
preparation of further LLVM merges.

MFC r307230 (by emaste):

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

MFC r307231 (by emaste):

libgcc_s: add libm dependencies from div{d,s,x}c3

compiler-rt's complex division support routines contain calls to
compiler builtins such as `__builtin_scalbnl`. Unfortunately Clang
turns these back into a call to `scalbnl`.

For now link libm's C version of the required support routines.

Reviewed by: ed
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D8190

MFC r307864 (by emaste):

Move the LLVM-based libgcc_s to /lib

When enabled, it should install in the same location as the existing
library.

Reported by: antoine

MFC r308001 (by emaste):

libgcc_eh/libgcc_s: apply hidden visibility only to static libs

MFC r308100 (by emaste):

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.

MFC r308294 (by emaste):

libgcc_s: make unspecified shlib symbols local

We want only symbols explicitly specified in the Version.map.

Sponsored by: The FreeBSD Foundation

MFC r308308 (by emaste):

Connect new LLVM-based libgcc_eh & libgcc_s to the build

Compiler-rt and LLVM's libunwind provide a suitable replacement for
libgcc.a, libgcc_eh.a, and libgcc_s.so.

Remove the now-unused LLVM_LIBUNWIND block from gnu/lib/libgcc.

PR: 213480 [exp-run]
Reviewed by: brooks, ed
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D8189

MFC r308379 (by emaste):

add __divdi3 and __udivdi3 to libgcc_s symbol version map

After r308294 they were missing on i386 (and previously were exported
only accidentally).

Reported by: antoine

MFC r308445 (by emaste):

add missing i386 symbols libgcc_s symbol version map

After r308294 they were missing on i386 (and previously were exported
only accidentally).

Reported by: antoine

MFC r312076 (by emaste):

libgcc_s: add libc DT_NEEDED to fix underlinking

PR: 216012
Reported by: jbeich
Sponsored by: The FreeBSD Foundation

MFC r316101 (by ngie):

Apply r315689 to lib/libgcc_s as well to unbreak the gcc xtoolchain build

lib/libgcc_s consumes lib/libcompiler_rt/Makefile*. The NO_WERROR.gcc in
lib/libcompiler_rt/Makefile doesn't seem to have made a difference in being
able to build this, so sprinkle NO_WERROR.gcc here as well.

Reported by: Jenkins (FreeBSD-head-amd64-gcc)
Tested with: amd64-gcc-6.3.0 (devel/amd64-xtoolchain-gcc)
Sponsored by: Dell EMC Isilon

MFC r320673 (by emaste):

Sort entries in libgcc_s Version.map

MFC r337585 (by dim):

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

Merge llvm, clang, compiler-rt, libc++, libunwind, lld, lldb and openmp
8.0.0 final release r356365.

MFC r306265 (by emaste):

Force LLVM_LIBUNWIND off if we don't have a C++11 compiler

Tested by: bde
Differential Revision: https://reviews.freebsd.org/D7746

MFC r308100 (by emaste):

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.

MFC r324998 (by bdrewery):

Prefix {TARGET,BUILD}_TRIPLE with LLVM_ to avoid Makefile.inc1 collision.

The Makefile.inc1 TARGET_TRIPLE is for specifying which -target is used
during the build of world.

Reviewed by: dim, imp
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D12792

MFC r329093 (by emaste):

Promote llvm-cov to a standalone option

Introduce WITH_/WITHOUT_LLVM_COV to match GCC's WITH_/WITHOUT_GCOV.
It is intended to provide a superset of the interface and functionality
of gcov.

It is enabled by default when building Clang, similarly to gcov and GCC.

This change moves one file in libllvm to be compiled unconditionally.
Previously it was included only when WITH_CLANG_EXTRAS was set, but the
complexity of a new special case for (CLANG_EXTRAS | LLVM_COV) is not
worth avoiding a tiny increase in build time.

Reviewed by: dim, imp
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D142645

MFC r331244 (by jhb):

Add support for MIPS to LLVM's libunwind.

This is originally based on a patch from David Chisnall for soft-float
N64 but has since been updated to support O32, N32, and hard-float ABIs.
The soft-float O32, N32, and N64 support has been committed upstream.
The hard-float changes are still in review upstream.

Enable LLVM_LIBUNWIND on mips when building with a suitable (C+11-capable)
toolchain. This has been tested with external GCC for all ABIs and
O32 and N64 with clang.

Reviewed by: emaste
Obtained from: CheriBSD (original N64 patch)
Sponsored by: DARPA / AFRL
Differential Revision: https://reviews.freebsd.org/D14701

MFC r336691 (by emaste):

llvm: remove __FreeBSD_version conditionals

All supported FreeBSD build host versions have backtrace.h, so we can
just eliminate that test. For futimes() we can test the compiler's
built-in __FreeBSD__ major version rather than relying on including
osreldate.h. This should reduce the frequency with which Clang gets
rebuilt when building world.

Reviewed by: dim
Sponsored by: The FreeBSD Foundation

MFC r337379 (by andrew):

Default to armv5te in LINT on arm. This should fix building LINT there.

MFC r337552:

Add optional LLVM BPF target support

BPF (eBPF) is an independent instruction set architecture which is
introduced in Linux a few years ago. Originally, eBPF execute
environment was only inside Linux kernel. However, recent years there
are some user space implementation (https://github.com/iovisor/ubpf,
https://doc.dpdk.org/guides/prog_guide/bpf_lib.html) and kernel space
implementation for FreeBSD is going on
(https://github.com/YutaroHayakawa/generic-ebpf).

The BPF target support can be enabled using WITH_LLVM_TARGET_BPF, as it
is not built by default.

Submitted by: Yutaro Hayakawa <yhayakawa3720@gmail.com>
Reviewed by: dim, bdrewery
Differential Revision: https://reviews.freebsd.org/D16033

MFC r337585:

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 r340287 (by emaste):

Consolidate gcov entries in OptionalObsoleteFiles

Sponsored by: The FreeBSD Foundation

MFC r340289 (by emaste):

llvm-cov: also install as gcov (if GNU gcov is disabled)

llvm-cov provides a gcov-compatible interface when invoked as gcov.

Reviewed by: dim, markj
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17923

MFC r340296 (by emaste):

Move llvm-profdata build into MK_LLVM_COV block

llvm-profdata is used with llvm-cov for code coverage (although llvm-cov
can also operate independently in a gcov-compatible mode).
Although llvm-profdata can be used independently of llvm-cov it makes
sense to group these under one option.

Also handle these in OptionalObsoleteFiles.inc while here.

Sponsored by: The FreeBSD Foundation

MFC r340300 (by emaste):

libllvm: Move SampleProfWriter to SRCS_MIN

It is required by llvm-profdata, now built by default under the
LLVM_COV knob. The additional complexity that would come from avoiding
building it if CLANG_EXTRAS and LLVM_COV are both disabled is not worth
the small savings in build time.

Sponsored by: The FreeBSD Foundation

MFC r340972 (by emaste):

llvm-objdump: initial man page

Based on llvm-objdump's online documentation and usage information.
This serves as a starting point; additional detail and cleanup still
required.

Also being submitted upstream in LLVM review D54864. I expect to use
this bespoke copy while we have LLVM 6.0 or 7.0 in FreeBSD; when we
update to LLVM 8.0 it should be upstream and we will switch to it.

PR: 233437
Reviewed by: bcr (man formatting)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18309

MFC r340973 (by emaste):

llvm-objdump.1: remove invalid options

Some options appear in llvm-objdump's usage information as a side effect
of its option parsing implementation and are not actually llvm-objdump
options. Reported in LLVM review https://reviews.llvm.org/D54864.

Reported by: Fangrui Song
Sponsored by: The FreeBSD Foundation

MFC r340975 (by emaste):

llvm-objdump.1: fix igor / mandoc -Tlint warnings

Accidentally omitted from r340972.

MFC r341055 (by emaste):

llvm-objdump.1: remove more unintentional options

Some options come from static constructors in LLVM libraries and are
automatically added to llvm's usage output. They're not really supposed
to be llvm-objdump options.

Reported by: Fangrui Song in LLVM review D54864
Sponsored by: The FreeBSD Foundation

MFC r344779:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
the upstream release_80 branch r355313 (effectively, 8.0.0 rc3). The
release will follow very soon, but no more functional changes are
expected.

Release notes for llvm, clang and lld 8.0.0 will soon be available here:
<https://releases.llvm.org/8.0.0/docs/ReleaseNotes.html>
<https://releases.llvm.org/8.0.0/tools/clang/docs/ReleaseNotes.html>
<https://releases.llvm.org/8.0.0/tools/lld/docs/ReleaseNotes.html>

PR: 236062
Relnotes: yes

MFC r344798 (by emaste):

libllvm: promote WithColor and xxhash to SRCS_MIN

The armv6 build failed in CI due to missing symbols (from these two
source files) in the bootstrap Clang.

This affected only armv6 because other Clang-using archs are using LLD
as the bootstrap linker, and thus include SRCS_MIW via LLD_BOOTSTRAP.

Reported by: CI, via lwhsu
Sponsored by: The FreeBSD Foundation

MFC r344825:

Add a few missed files to the MK_LLVM_TARGET_BPF=yes case, otherwise
clang and various other executables will fail to link with undefined
symbols.

Reported by: O. Hartmann <ohartmann@walstatt.org>

MFC r344852:

Put in a temporary workaround for what is likely a gcc 6 bug (it does
not occur with gcc 7 or later). This should prevent the following error
from breaking the head-amd64-gcc CI builds:

In file included from /workspace/src/contrib/llvm/tools/lldb/source/API/SBMemoryRegionInfo.cpp:14:0:
/workspace/src/contrib/llvm/tools/lldb/include/lldb/Target/MemoryRegionInfo.h:128:54: error: 'template<class _InputIterator> lldb_private::MemoryRegionInfos::MemoryRegionInfos(_InputIterator, _InputIterator, const allocator_type&)' inherited from 'std::__1::vector<lldb_private::MemoryRegionInfo>'
using std::vector<lldb_private::MemoryRegionInfo>::vector;
^~~~~~
/workspace/src/contrib/llvm/tools/lldb/include/lldb/Target/MemoryRegionInfo.h:128:54: error: conflicts with version inherited from 'std::__1::vector<lldb_private::MemoryRegionInfo>'

Reported by: CI

MFC r344896:

Pull in r354937 from upstream clang trunk (by Jörg Sonnenberger):

Fix inline assembler constraint validation

The current constraint logic is both too lax and too strict. It fails
for input outside the [INT_MIN..INT_MAX] range, but it also
implicitly accepts 0 as value when it should not. Adjust logic to
handle both correctly.

Differential Revision: https://reviews.llvm.org/D58649

Pull in r355491 from upstream clang trunk (by Hans Wennborg):

Inline asm constraints: allow ICE-like pointers for the "n"
constraint (PR40890)

Apparently GCC allows this, and there's code relying on it (see bug).

The idea is to allow expression that would have been allowed if they
were cast to int. So I based the code on how such a cast would be
done (the CK_PointerToIntegral case in
IntExprEvaluator::VisitCastExpr()).

Differential Revision: https://reviews.llvm.org/D58821

These should fix assertions and errors when using the inline assembly
"n" constraint in certain ways.

In case of devel/valgrind, a pointer was used as the input for the
constraint, which lead to "Assertion failed: (isInt() && "Invalid
accessor"), function getInt".

In case of math/secp256k1, a very large integer value was used as input
for the constraint, which lead to "error: value '4624529908474429119'
out of range for constraint 'n'".

PR: 236216, 236194

MFC r344951:

Merge llvm, clang, compiler-rt, libc++, lld, and lldb release_80 branch
r355677 (effectively, 8.0.0 rc4), resolve conflicts, and bump version
numbers.

PR: 236062

MFC r345018:

Merge LLVM libunwind trunk r351319, from just before upstream's
release_80 branch point. Afterwards, we will merge the rest of the
changes in the actual release_80 branch.

PR: 236062

MFC r345019:

Merge LLVM libunwind release_80 branch r355677 (effectively, 8.0.0 rc4).

PR: 236062

MFC r345021:

Pull in r355854 from upstream llvm trunk (by Jonas Paulsson):

[RegAlloc] Avoid compile time regression with multiple copy hints.

As a fix for https://bugs.llvm.org/show_bug.cgi?id=40986 ("excessive
compile time building opencollada"), this patch makes sure that no
phys reg is hinted more than once from getRegAllocationHints().

This handles the case were many virtual registers are assigned to the
same physreg. The previous compile time fix (r343686) in
weightCalcHelper() only made sure that physical/virtual registers are
passed no more than once to addRegAllocationHint().

Review: Dimitry Andric, Quentin Colombet
https://reviews.llvm.org/D59201

This should fix a hang when compiling certain generated .cpp files in
the graphics/opencollada port.

PR: 236313

MFC r345068 (by jhb):

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

MFC r345073:

Revert r308867 (which was originally committed in the clang390-import
project branch):

Work around LLVM PR30879, which is about a bad interaction between
X86 Call Frame Optimization on i386 and libunwind, by disallowing the
optimization for i386-freebsd12.

This should fix some instances of broken exception handling when
frame pointers are omitted, in particular some unittests run during
the build of editors/libreoffice.

This hack will be removed as soon as upstream has implemented a more
permanent fix for this problem.

And indeed, after r345018 and r345019, which updated LLVM libunwind to
the most recent version, the above workaround is no longer needed. The
upstream commit which fixed this is:

https://llvm.org/viewvc/llvm-project?view=revision&revision=292723

Specifically, 32 bit (i386-freebsd) executables optimized with omitted
frame pointers and Call Frame Optimization should now behave correctly
when a C++ exception is thrown, and the stack is unwound.

Upstream PR: https://llvm.org/bugs/show_bug.cgi?id=30879
PR: 236062

MFC r345152:

Merge llvm, clang, compiler-rt, libc++, libunwind, lld, and lldb
release_80 branch r356034 (effectively, 8.0.0 rc5), resolve conflicts,
and bump version numbers.

PR: 236062

MFC r345231:

Add LLVM openmp trunk r351319 (just before the release_80 branch point)
to contrib/llvm. This is not yet connected to the build, the glue for
that will come in a follow-up commit.

PR: 236062

MFC r345232:

Bootstrap svn:mergeinfo on contrib/openmp.

PR: 236062

MFC r345233:

Merge openmp release_80 branch r356034 (effectively, 8.0.0 rc5).

PR: 236062

MFC r345234:

Add openmp __kmp_gettid() wrapper, using pthread_getthreadid_np(3).
This has also been submitted upstream.

PR: 236062

MFC r345283:

Enable building libomp.so for 32-bit x86. This is done by selectively
enabling the functions that save and restore MXCSR, since access to this
register requires SSE support.

Note that you may run into other issues with OpenMP on i386, since this
*not* yet supported upstream, and certainly not extensively tested.

PR: 236062, 236582

MFC r345345:

Merge llvm, clang, compiler-rt, libc++, libunwind, lld, lldb and openmp
8.0.0 final release r356365. There were no functional changes since the
most recent merge, of 8.0.0 rc5.

Release notes for llvm, clang, lld and libc++ 8.0.0 are now available:

https://llvm.org/releases/8.0.0/docs/ReleaseNotes.html
https://llvm.org/releases/8.0.0/tools/clang/docs/ReleaseNotes.html
https://llvm.org/releases/8.0.0/tools/lld/docs/ReleaseNotes.html
https://llvm.org/releases/8.0.0/projects/libcxx/docs/ReleaseNotes.html

PR: 236062

MFC r345349:

Pull in r352826 from upstream lld trunk (by Fangrui Song):

[ELF] Support --{,no-}allow-shlib-undefined

Summary:
In ld.bfd/gold, --no-allow-shlib-undefined is the default when
linking an executable. This patch implements a check to error on
undefined symbols in a shared object, if all of its DT_NEEDED entries
are seen.

Our approach resembles the one used in gold, achieves a good balance
to be useful but not too smart (ld.bfd traces all DSOs and emulates
the behavior of a dynamic linker to catch more cases).

The error is issued based on the symbol table, different from
undefined reference errors issued for relocations. It is most
effective when there are DSOs that were not linked with -z defs (e.g.
when static sanitizers runtime is used).

gold has a comment that some system libraries on GNU/Linux may have
spurious undefined references and thus system libraries should be
excluded (https://sourceware.org/bugzilla/show_bug.cgi?id=6811). The
story may have changed now but we make --allow-shlib-undefined the
default for now. Its interaction with -shared can be discussed in the
future.

Reviewers: ruiu, grimar, pcc, espindola

Reviewed By: ruiu

Subscribers: joerg, emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D57385

Pull in r352943 from upstream lld trunk (by Fangrui Song):

[ELF] Default to --no-allow-shlib-undefined for executables

Summary:
This follows the ld.bfd/gold behavior.

The error check is useful as it captures a common type of ld.so
undefined symbol errors as link-time errors:

// a.cc => a.so (not linked with -z defs)
void f(); // f is undefined
void g() { f(); }

// b.cc => executable with a DT_NEEDED entry on a.so
void g();
int main() { g(); }

// ld.so errors when g() is executed (lazy binding) or when the program is started (-z now)
// symbol lookup error: ... undefined symbol: f

Reviewers: ruiu, grimar, pcc, espindola

Reviewed By: ruiu

Subscribers: llvm-commits, emaste, arichardson

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57569

Together, these add support for --no-allow-shlib-undefined, and make it
the default for executables, so they will fail to link if any symbols
from needed shared libraries are undefined.

Reported by: jbeich
PR: 236062, 236141

MFC r345449:

Pull in r356809 from upstream llvm trunk (by Eli Friedman):

[ARM] Don't form "ands" when it isn't scheduled correctly.

In r322972/r323136, the iteration here was changed to catch cases at
the beginning of a basic block... but we accidentally deleted an
important safety check. Restore that check to the way it was.

Fixes https://bugs.llvm.org/show_bug.cgi?id=41116

Differential Revision: https://reviews.llvm.org/D59680

This should fix "Assertion failed: (LiveCPSR && "CPSR liveness tracking
is wrong!"), function UpdateCPSRUse" errors when building the devel/xwpe
port for armv7.

PR: 236062, 236568