Summary:
This patch reorganizes a lot of the code used to check for compatibility
with the current environment. The main bulk of this patch involves
moving from using a separate `__tgt_image_info` struct (which just
contains a string for the architecture) to instead simply checking this
information from the ELF directly. Checking information in the ELF is
very inexpensive as creating an ELF file is simply writing a base
pointer.

The main desire to do this was to reorganize everything into the ELF
image. We can then do the majority of these checks without first
initializing the plugin. A future patch will move the first ELF checks
to happen without initializing the plugin so we no longer need to
initialize and plugins that don't have needed images.

This patch also adds a lot more sanity checks for whether or not the ELF
is actually compatible. Such as if the images have a valid ABI, 64-bit
width, executable, etc.

Summary:
Recently we added support for detecting the CUDA processor with the ELF
flags. This allows us to get a string representation of it in other
code. This will be used by the offloading runtime.

`cmp; bc; isync` is more performant than `lwsync` theoretically.

64-bit platform already features it, now implement it for 32-bit
platform.

Makes constructing SchedGroups of this type easier, and provides ability
to create them with __builtin_amdgcn_sched_group_barrier

https://github.com/llvm/llvm-project/pull/75635#issuecomment-1863662913

Differential Revision: https://reviews.llvm.org/D159232
```
Running ./ranges_contains.libcxx.out
Run on (10 X 24.121 MHz CPU s)
CPU Caches:
  L1 Data 64 KiB (x10)
  L1 Instruction 128 KiB (x10)
  L2 Unified 4096 KiB (x5)
Load Average: 3.37, 6.77, 5.27
--------------------------------------------------------------------
Benchmark                          Time             CPU   Iterations
--------------------------------------------------------------------
bm_contains_char/16             1.88 ns         1.87 ns    371607095
bm_contains_char/256            7.48 ns         7.47 ns     93292285
bm_contains_char/4096           99.7 ns         99.6 ns      7013185
bm_contains_char/65536          1296 ns         1294 ns       540436
bm_contains_char/1048576       23887 ns        23860 ns        29302
bm_contains_char/16777216     389420 ns       389095 ns         1796
bm_contains_int/16              7.14 ns         7.14 ns     97776288
bm_contains_in...

Build bots are failing in post submit. Unclear why but can't reproduce
locally.
Disable this test for asan for now.

This reverts commit 44dc1e0b.

Causes non-determinism, see #75987.

Use the `vector::makeArithReduction` helper as the source-of-truth of
reduction to arith ops lowering.

Zvfbfmin does not have any scalar operands making this an unnecessary
dependency. The spec was just updated to remove this. See
https://github.com/riscv/riscv-bfloat16/commit/86d7a74f4b928e981f79f6d84a4592e6e9e4c0e9

This fixes a correctness issue where Xsfvfwmaccqqq was incorrectly
depending on Zfbfmin. The SiFive CPUs that support Xsfvfwmaccqqq do not
implement Zfbfmin, but do implement Zvfbfmin based on a previous
understanding that it only requires Zve32f. I've added tests for this
feature to raise the bar for adding dependencies to it in the future.

This a follow-up PR from this other one:
https://github.com/llvm/llvm-project/pull/74413

Nothing calls into these two methods, so we (@DavidSpickett,
@adrian-prantl, and I) agreed to remove them once we merged the previous
PR.

dlsym signs text symbols as functions rather than data in dyld, so match
that for orc runtime dlsym. This fixes run_program on arm64e.

Test failed on ppc
(https://lab.llvm.org/buildbot/#/builders/231/builds/18902), and logs
shows missed import.

Cannot reproduce this with machines I could access so far.
https://gcc.gnu.org/wiki/CompileFarm seems to provide ppc64 machine.
Mark the thinlto icp test as unsupported for now.

reading dylibs

* This is a better fix than what I originally did to appease CI.

This implements a post-commit suggestion for #75679.

…e introduced by oneAPI DPC++ compiler 2024.0

Looks like adding attributes to lambdas wasn't added to ISO C++ until
C++23.
Forget lambdas and just use a static function.

In the change that added `--gap-fill`, the condition to choose the
sections to write in `BinaryWriter::write()` did not exclude zero-size
sections. However, zero-size sections did not have correct offsets
assigned in `BinaryWriter::finalize()`. The result is either a failed
assertion, or memory corruption due to writing to the buffer beyond its
size.
To fix this, exclude zero-size sections from writing. Also, add a zero-size
section to the test, which would trigger the problem.

https://github.com/llvm/llvm-project/pull/75635#issuecomment-1863433937

```
/b/s/w/ir/x/w/llvm_build/./bin/clang --target=aarch64-unknown-linux-gnu --sysroot=/b/s/w/ir/x/w/cipd/linux -DHAS_ASM_LSE -DVISIBILITY_HIDDEN  --target=aarch64-unknown-linux-gnu -O2 -g -DNDEBUG -fno-lto -std=c11 -fPIC -fno-builtin -fvisibility=hidden -fomit-frame-pointer -DCOMPILER_RT_HAS_FLOAT16 -MD -MT CMakeFiles/clang_rt.builtins-aarch64.dir/cpu_model/aarch64.c.o -MF CMakeFiles/clang_rt.builtins-aarch64.dir/cpu_model/aarch64.c.o.d -o CMakeFiles/clang_rt.builtins-aarch64.dir/cpu_model/aarch64.c.o -c /b/s/w/ir/x/w/llvm-llvm-project/compiler-rt/lib/builtins/cpu_model/aarch64.c
In file included from /b/s/w/ir/x/w/llvm-llvm-project/compiler-rt/lib/builtins/cpu_model/aarch64.c:43:
/b/s/w/ir/x/w/llvm-llvm-project/compiler-rt/lib/builtins/cpu_model/aarch64/lse_atomics/sysauxv.inc:5:41: error: use of undeclared identifier 'HWCAP_ATOMICS'
    5 |   __aarch64_have_lse_atomics = (hwcap & HWCAP_ATOMICS) != 0;
      |                                         ^
1 error generated.
```

This is breaking Android compiler-rt builds.

This patch fixes:

  clang/lib/Interpreter/CodeCompletion.cpp:126:35: error: 'startswith'
  is deprecated: Use starts_with instead
  [-Werror,-Wdeprecated-declarations]

  clang/lib/Interpreter/CodeCompletion.cpp:189:42: error: 'startswith'
  is deprecated: Use starts_with instead
  [-Werror,-Wdeprecated-declarations]

This patch fixes:

  third-party/unittest/googletest/include/gtest/gtest.h:1379:11:
  error: comparison of integers of different signs: 'const int' and
  'const unsigned int' [-Werror,-Wsign-compare]

  llvm/unittests/Support/CommandLineTest.cpp:2294:3: note: in
  instantiation of function template specialization
  'testing::internal::EqHelper::Compare<int, unsigned int, nullptr>'
  requested here

This patch contains changes from
002d471a, in
addition to a bug fix that added a virtual destructor to
`CompletionContextHandler`

The original changes in the orginal commit piggybacks on clang's
semantic modules to enable semantic completion.  In particular, we use
`CodeCompletionContext` to differentiate two types of code completion.
We also
extract the relevant type information from it.

Otherwise for ASAN configured runs of the test, the test will fail due
to the
sanitizer rather than via SIGABRT.

Summary:
A recent patch allowed us to easily replace GNU atomics with scoped
variants that make use of the backend's handling for more permissive
scopes. The default is full "system" scope, that means the atomic
operation must be consistent with operations that may happen on the
host's memory. This is generally only required for processes that are
communicating with something via global fine-grained memory. This patch
uses these atomics to make everything device scoped, as nothing in the
OpenMP runtime should depend on the host.

This is only provided as a very new clang extension but the DeviceRTL is
only compiled with clang so it is always available.

Reland the reland "[PGO][GlobalValue][LTO]In GlobalValues::getGlobalIdentifier, use semicolon as delimiter for local-linkage varibles. "   (#75954)

Simplify the compiler-rt test to make it more general for different
platforms, and use `*DAG` matchers for lines that may be emitted
out-of-order.
- The compiler-rt test passed on a Windows machine. Previously name
matchers don't work for MSVC mangling
(https://lab.llvm.org/buildbot/#/builders/127/builds/59907)
- `*DAG` matchers fixed the error in
https://lab.llvm.org/buildbot/#/builders/94/builds/17924

This is the second reland and fixed errors caught in first reland
(https://github.com/llvm/llvm-project/pull/75860)

**Original commit message**
Commit fe051934 (phab D156569), IRPGO names uses format
`[<filepath>;]<linkage-name>` while prior format is
`[<filepath>:<mangled-name>`. The format change would break the use case
demonstrated in (updated)
`llvm/test/Transforms/PGOProfile/thinlto_indirect_call_promotion.ll` and
`compiler-rt/test/prof...

Use a size smaller than the smallest supported page size so that we
don't
clobber over any guard pages, which may result in a segfault before
__stack_chk_fail can be called.

Also, move __stack_chk_fail outside of our namespace.

The patch introduces a `SubCommandGroup` class which represents a list
of subcommands. An option can be added to all these subcommands using
one `cl::sub(group)` command. This simplifies the declaration of options
that are shared across multiple subcommands of a tool.

Make the `--implicit-check-not` account for the file extension as well.
This will still fail if we ever have a builder with `.dylib` in its
name, and we probably want a more robust solution, but this addresses
the immediate issue.

Fixes https://github.com/llvm/llvm-project/issues/75850
Fixes https://github.com/llvm/llvm-project/issues/75910

The patch adds a helper method to iterate over all subcommands to which
an option belongs. Duplicate code is removed and replaced with calls to
this new method.

__stack_chk_fail should be provided by libc.a, not startup files.

Add __stack_chk_fail to existing linux and arm entrypoints. On Windows
(when
not targeting MinGW), it seems that the corresponding function
identifier is
__security_check_cookie, so no entrypoint is added for Windows.
Baremetal
targets also ought to be compileable with `-fstack-protector*`

There is no common header for this prototype, since calls to
__stack_chk_fail
are meant to be inserted by the compiler upon function return when
compiled
`-fstack-protector*`.

Adds emitting the exception table and the EH registers for XPLINK.

---------

Co-authored-by: Yusra Syeda <yusra.syeda@ibm.com>

We included these in the commit message when we added
`-ffat-lto-objects`, but they should be in the documentation as well.