Commit Graph

101 Commits

Author SHA1 Message Date
Alex Richardson 8df257a6d0 [libunwind] Ensure test/libunwind_01.pass is not completely inlined
By adding noinline and calling fprintf before returning we ensure that
every function will have a distinct call frame and that the return address
will always be saved instead of saving the target in main as the result.

Before this change all backtraces were always backtrace -> main -> _start,
i.e. always exactly three entries. This happenend because all calls were
inlined in main() and the test just happenend to pass because there is at
least _start before main.

I found this while fixing some bugs in libunwind for CHERI and noticed that
the test was passing even though the code was completely broken.

Obtained from: https://github.com/CTSRD-CHERI/llvm-project

Reviewed By: #libunwind, ldionne, MaskRay

Differential Revision: https://reviews.llvm.org/D126611
2022-06-20 09:05:49 +00:00
Xing Xue dfaee3c9cf [libunwind][ci][AIX] Add libunwind to buildbot CI
Summary:
This patch changes scripts to add libunwind CI on AIX. Test config file ibm-libunwind-shared.cfg.in is introduced for testing on AIX.

Reviewed by: ldionne, MaskRay, libunwind, ibc++abi

Differential Revision: https://reviews.llvm.org/D126017
2022-06-02 09:03:10 -04:00
Louis Dionne 719bf2d9d9 [runtimes] Officially deprecate the legacy testing configuration system
Add a warning and tweak the release note to explain that the deprecation
targets libc++, libc++abi and libuwnind as well.

Also, as a fly-by, ensure that our CI runs the legacy testing configuration
for libc++, libc++abi and libunwind. This doesn't matter too much since
it's deprecated, but we might as well test it properly.

Differential Revision: https://reviews.llvm.org/D126478
2022-05-27 13:15:48 -04:00
Louis Dionne 92bbcfaa97 [libunwind] Tidy-up the testing configuration for libunwind
Start testing Apple backdeployment with older libunwinds, and stop
explicitly specifying the libunwind testing config, since it is
already selected correctly by default.

Differential Revision: https://reviews.llvm.org/D126470
2022-05-26 15:29:39 -04:00
Shoaib Meenai 0be0a53df6 [libunwind] Use process_vm_readv to avoid potential segfaults
We've observed segfaults in libunwind when attempting to check for the
Linux aarch64 sigreturn frame, presumably because of bad unwind info
leading to an incorrect PC that we attempt to read from. Use
process_vm_readv to read the memory safely instead.

The s390x code path should likely follow suit, but I don't have the
hardware to be able to test that, so I didn't modify it here either.

Reviewed By: MaskRay, rprichard, #libunwind

Differential Revision: https://reviews.llvm.org/D126343
2022-05-26 09:12:51 -07:00
Louis Dionne 422ec52438 [libunwind] Introduce a cmake-bridge.cfg.in file to reduce test config duplication
Differential Revision: https://reviews.llvm.org/D125981
2022-05-20 09:36:29 -04:00
Louis Dionne a5f36259a2 [libunwind] Remove unused _LIBUNWIND_HAS_NO_THREADS macro in tests
The _LIBUNWIND_HAS_NO_THREADS macro is only picked up by libunwind
inside its sources, so it is only required when it builds. It doesn't
need to be defined when running the tests.
2022-05-19 10:58:13 -04:00
Louis Dionne fa7ce8e685 [runtimes] Fix the build of merged ABI/unwinder libraries
Also, add a CI job that tests this configuration. The exact configuration
is that we build a shared libc++ and merge objects for the ABI library
and the unwinder library into it.

Differential Revision: https://reviews.llvm.org/D125903
2022-05-19 10:49:36 -04:00
Daniel Kiss fd864238fc Revert "[libunwind][AArch64] Add support for DWARF expression for RA_SIGN_STATE."
This reverts commit f6366ef7f4.
2022-05-15 21:42:07 +02:00
Daniel Kiss f6366ef7f4 [libunwind][AArch64] Add support for DWARF expression for RA_SIGN_STATE.
Program may set the RA_SIGN_STATE pseudo register by expressions.
Libunwind expected only the DW_CFA_AARCH64_negate_ra_state could change the value
of the register which leads to runtime errors on PAC enabled systems.
In the recent version of the aadwarf64[1] a limitation is added[2] to forbid the mixing the
DW_CFA_AARCH64_negate_ra_state with other DWARF Register Rule Instructions.

[1] https://github.com/ARM-software/abi-aa/releases/tag/2022Q1
[2] https://github.com/ARM-software/abi-aa/pull/129

Reviewed By: #libunwind, MaskRay

Differential Revision: https://reviews.llvm.org/D123692
2022-05-13 10:05:59 +02:00
Ulrich Weigand 71672375fe [libunwind][SystemZ] Unwind out of signal handlers
Unwinding out of signal handlers currently does not work since
the sigreturn trampoline is not annotated with CFI data.

Fix this by detecting the sigreturn trampoline during unwinding
and providing appropriate unwind data manually. This follows
closely the approach used by existing code for the AArch64 target.

Reviewed by: MaskRay

Differential Revision: https://reviews.llvm.org/D124765
2022-05-04 10:43:11 +02:00
Vladimir Vereschaka db92019ab9 [libunwind] Update the test configuration files to support the remote execution.
These changes allow remote execution for the libunwind library tests.

Differential Revision: https://reviews.llvm.org/D123890
2022-04-25 17:33:03 -07:00
Louis Dionne 282b3eb723 [libunwind] Add missing licenses in test files 2022-04-03 08:55:57 -04:00
Louis Dionne cb055e51f9 [libc++] Add a CI job running MSAN
For some reason, we've been going without a MSAN CI job, even though
even run-buildbot defined a generic-msan job. This must have been an
oversight that went unnoticed. Thanks to @EricWF for the catch.

Differential Revision: https://reviews.llvm.org/D120851
2022-03-31 09:31:22 -04:00
Louis Dionne 3ee0cec88e [runtimes] Remove FOO_TARGET_TRIPLE, FOO_SYSROOT and FOO_GCC_TOOLCHAIN
Instead, folks can use the equivalent variables provided by CMake
to set those. This removal aims to reduce complexity and potential
for confusion when setting the target triple for building the runtimes,
and make it correct when `CMAKE_OSX_ARCHITECTURES` is used (right now
both `-arch` and `--target=` will end up being passed, which is downright
incorrect).

Differential Revision: https://reviews.llvm.org/D112155
2022-03-01 08:39:42 -05:00
Fangrui Song 84647ff38c [libunwind][test] remember_state_leak.pass.sh.s: link with -no-pie
The no-pic large code model style `movabsq $callback, %rsi` does not work with -pie.
2022-02-25 19:55:56 +00:00
Leonard Chan f178a05f22 [libunwind] Fix unwind_leaffunction test
It's possible for this test not to pass if the libc used does not provide
unwind info for raise. We can replace it with __builtin_cast, which can lead
to a SIGTRAP on x86_64 and a SIGILL on aarch64.

Using this alternative, a nop is needed before the __builtin_cast. This is
because libunwind incorrectly decrements pc, which can cause pc to jump into
the previous function and use the incorrect FDE.

Differential Revision: https://reviews.llvm.org/D114818
2021-12-03 11:21:20 -08:00
Louis Dionne fa1c077b41 [runtimes] Remove support for GCC-style 32 bit multilib builds
This patch removes the ability to build the runtimes in the 32 bit
multilib configuration, i.e. using -m32. Instead of doing this, one
should cross-compile the runtimes for the appropriate target triple,
like we do for all other triples.

As it stands, -m32 has several issues, which all seem to be related to
the fact that it's not well supported by the operating systems that
libc++ support. The simplest path towards fixing this is to remove
support for the configuration, which is also the best course of action
if there is little interest for keeping that configuration. If there
is a desire to keep this configuration around, we'll need to do some
work to figure out the underlying issues and fix them.

Differential Revision: https://reviews.llvm.org/D114473
2021-12-01 12:57:01 -05:00
Louis Dionne ebfeeec4c4 [libunwind] Fix testing with sanitizers enabled
When testing with sanitizers enabled, we need to link against a plethora
of system libraries. Using `-nodefaultlibs` like we used to breaks this,
and we would have to add all these system libraries manually, which is
not portable and error prone. Instead, stop using `-nodefaultlibs` so
that we get the libraries added by default by the compiler.

The only caveat with this approach is that we are now relying on the
fact that `-L <path-to-local-libunwind>` will cause the just built
libunwind to be selected before the system implementation (either of
libunwind or libgcc_s.so), which is somewhat fragile.

This patch also turns the 32 bit multilib build into a soft failure
since we are in the process of removing it anyway, see D114473 for
details. This patch is incompatible with the 32 bit multilib build
because Ubuntu does not provide a proper libstdc++ for 32 bits, and
that is required when running with sanitizers enabled.

Differential Revision: https://reviews.llvm.org/D114385
2021-11-25 15:28:17 -05:00
Xing Xue 11982eed2b [libunwind][AIX] Mark signal_frame.pass.cpp UNSUPPORTED on AIX
Summary:
This patch marks libunwind test case signal_frame.pass.cpp as UNSUPPORTED on AIX because the AIX assembler does not support CFI directives.

Reviewed by: danielkiss, MaskRay, ldionne, libunwind

Differential Revision: https://reviews.llvm.org/D113607
2021-11-18 10:24:58 -05:00
Louis Dionne a55632a069 [libc++] Temporarily mark tests as UNSUPPORTED to get the CI green
After recent changes to the Docker image, all hell broke loose and the
CI started failing. This patch marks a few tests as unsupported until
we can figure out what the issues are and fix them.

In the future, it would be ideal if the nodes could pick up the Dockerfile
present in the revision being tested, which would allow us to test changes
to the Dockerfile in the CI, like we do for all other code changes.

Differential Revision: https://reviews.llvm.org/D112737
2021-10-28 16:30:42 -04:00
Louis Dionne 3e39bbf5f9 [libunwind] Simplify the executor used in the tests
Instead of going through libc++'s run.py, we can simply run the executable
directly since we don't need to setup a working directory or control the
environment.

Differential Revision: https://reviews.llvm.org/D112649
2021-10-27 17:30:07 -04:00
Louis Dionne e6f39c8b48 [libunwind] Fix path to libunwind for per-target-runtime-dir builds
We recently introduced a from-scratch config to run the libunwind tests.
However, that config was always looking for libunwind in <install>/lib,
and never in <install>/<target>/lib, which is necessary for tests to
work when the per-target-runtime-dir configuration is enabled.

This commit fixes that. I believe this is what caused the CI failures we
saw after 5a8ad80b6f and caused it to be reverted.

Differential Revision: https://reviews.llvm.org/D112322
2021-10-22 14:36:14 -04:00
Louis Dionne 6fd55bba61 [libunwind] Add a from-scratch config for running libunwind tests
Running tests for libunwind is a lot simpler than running tests for
libc++, so a simple Lit config file is sufficient. The benefit is that
we disentangle the libunwind test configuration from the libc++ and
libc++abi test configuration. The setup was too complicated, which led
to some bugs (notably we were running against the system libunwind on
Apple platforms).

Differential Revision: https://reviews.llvm.org/D111664
2021-10-19 12:03:58 -04:00
Louis Dionne df3de7647e [libc++abi] Change LIBCXXABI_NO_TIMER to LIBCXXABI_USE_TIMER
Instead of always defining LIBCXXABI_NO_TIMER to run the tests, only
define LIBCXXABI_USE_TIMER when we want to enable the timer. This makes
the libc++abi testing configuration simpler.

As a fly-by fix, remove the unused LIBUNWIND_NO_TIMER macro from libunwind.

Differential Revision: https://reviews.llvm.org/D111667
2021-10-13 08:02:31 -04:00
Louis Dionne f6a74908a7 [runtimes] Add tests for vendor-specific properties
Vendors take libc++ and ship it in various ways. Some vendors might
ship it differently from what upstream LLVM does, i.e. the install
location might be different, some ABI properties might differ, etc.

In the past few years, I've come across several instances where
having a place to test some of these properties would have been
incredibly useful. I also just got bitten by the lack of tests
of that kind, so I'm adding some now.

The tests added by this commit for Apple platforms have numerous
TODOs that capture discrepancies between the upstream LLVM CMake
and the slightly-modified build we perform internally to produce
Apple's system libc++. In the future, the goal would be to upstream
all those differences so that it's possible to build a faithful
Apple system libc++ with the upstream LLVM sources only.

But this isn't only useful for Apple - this lays out the path for
any vendor being able to add their own checks (either upstream or
downstream) to libc++.

This is a re-application of 9892d1644f, which was reverted in 138dc27186
because it broke the build. The issue was that we didn't apply the required
changes to libunwind and our CI didn't notice it because we were not
running the libunwind tests. This has been fixed now, and we're running
the libunwind tests in CI now too.

Differential Revision: https://reviews.llvm.org/D110736
2021-10-07 15:46:20 -04:00
Louis Dionne 60fe1f59d0 [runtimes][ci] Run the tests for libunwind in the CI
We should arguably have always been doing that. The state of libunwind
is quite sad, so this commit adds several XFAILs to make the CI pass.
We need to investigate why so many tests are not passing in some
configurations, but I'll defer that to folks who actually work on
libunwind for lack of bandwidth.

Differential Revision: https://reviews.llvm.org/D110872
2021-10-06 11:25:26 -04:00
Daniel Kiss 77aa9ca92a [libunwind] Support cfi_undefined and cfi_register for float registers.
During a backtrace the `.cfi_undefined` for a float register causes an assert in libunwind.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D110144
2021-09-27 12:04:02 +02:00
Daniel Kiss f5b997e6b7 [Unwind] Harmonise exception class for EHABI spec.
EHABI defines the exception class as char[8] instead of uint64_t [1].
For ABI compatibility the ABI the definition needs to be updated.

[1] https://github.com/ARM-software/abi-aa/blob/main/ehabi32/ehabi32.rst#82language-independent-unwinding-types-and-functions

Reviewed By: manojgupta, MaskRay, #libunwind

Differential Revision: https://reviews.llvm.org/D109047
2021-09-02 11:31:03 +02:00
gejin 21b25a1fb3 [libunwind] Support stack unwind in CET environment
Control-flow Enforcement Technology (CET), published by Intel,
introduces shadow stack feature aiming to ensure a return from
a function is directed to where the function was called.
In a CET enabled system, each function call will push return
address into normal stack and shadow stack, when the function
returns, the address stored in shadow stack will be popped and
compared with the return address, program will fail if the 2
addresses don't match.
In exception handling, the control flow may skip some stack frames
and we must adjust shadow stack to avoid violating CET restriction.
In order to achieve this, we count the number of stack frames skipped
and adjust shadow stack by this number before jumping to landing pad.

Reviewed By: hjl.tools, compnerd, MaskRay
Differential Revision: https://reviews.llvm.org/D105968

Signed-off-by: gejin <ge.jin@intel.com>
2021-08-26 16:20:38 +08:00
Vitaly Buka 2f1ee56f3c [unwind] Handle UNW_X86_64_RIP register
In some binaries, built with clang/lld, libunwind crashes
with "unsupported x86_64 register" for regNum == 16:

Differential Revision: https://reviews.llvm.org/D107919
2021-08-12 12:08:07 -07:00
Daniel Kiss db126ae243 [Arm][Unwind][libc++abi] Add _Unwind_ForcedUnwind to EHABI.
_Unwind_ForcedUnwind is not mandated by the EHABI but for compatibilty
reasons adding so the interface to higher layers would be the same.
Dropping EHABI specific _Unwind_Stop_Fn definition since it is not defined by EHABI.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D89570
2021-08-11 10:15:53 +02:00
Louis Dionne 395271ad11 [runtimes] Simplify how we set the target triple
Instead of using TARGET_TRIPLE, which is always set to LLVM_DEFAULT_TARGET_TRIPLE,
use that variable directly to populate the various XXXX_TARGET_TRIPLE
variables in the runtimes.

This re-applies 77396bbc98 and 5099e01568, which were reverted in
850b57c5fb because they broke the build.

Differential Revision: https://reviews.llvm.org/D106009
2021-07-16 10:33:39 -04:00
Louis Dionne 0c3401c86e [runtimes] Serialize all Lit params instead of passing them to add_lit_testsuite
add_lit_testsuite() takes Lit parameters passed to it and adds them
to the parameters used globally when running all test suites. That
means that a target like `check-all`, which ends up calling Lit on
the whole monorepo, will see the test parameters for all the individual
project's test suites.

So, for example, it would see `--param std=c++03` (from libc++abi), and
`--param std=c++03` (from libc++), and `--param whatever` (from another
project being tested at the same time). While always unclean, that works
when the parameters all agree. However, if the parameters share the same
name but have different values, only one of those two values will be used
and it will be incredibly confusing to understand why one of the test
suites is being run with the incorrect parameter value.

For that reason, this commit moves away from using add_lit_testsuite()'s
PARAM functionality, and serializes the parameter values for the runtimes
in the generated config.py file instead, which is local to the specific
test suite.

Differential Revision: https://reviews.llvm.org/D105991
2021-07-15 07:53:15 -04:00
Louis Dionne 850b57c5fb [runtimes] Bring back TARGET_TRIPLE
This commit reverts 5099e01568 and 77396bbc98, which broke the build
in various ways. I'm reverting until I can investigate, since that
change appears to be way more subtle than it seemed.
2021-07-14 15:15:22 -04:00
Louis Dionne 77396bbc98 [runtimes] NFCI: Drop intermediate CMake variable TARGET_TRIPLE
We might as well use the various XXX_TARGET_TRIPLE variables directly.
2021-07-14 10:49:28 -04:00
Louis Dionne f7d8754312 [runtimes] Move enable_32bit to the DSL
This is necessary for from-scratch configurations to support the 32-bit
mode of the test suite.

Differential Revision: https://reviews.llvm.org/D105435
2021-07-06 08:42:07 -04:00
Louis Dionne c360553c15 [runtimes] Simplify how we specify XFAIL & friends based on the triple
Now that Lit supports regular expressions inside XFAIL & friends, it is
much easier to write Lit annotations based on the triple.

Differential Revision: https://reviews.llvm.org/D104747
2021-07-01 14:03:30 -04:00
Louis Dionne 58a230455b [libc++] Serialize Lit parameters to make them available to from-scratch configs
Before this patch, Lit parameters that were set as a result of CMake
options were not made available to from-scratch configs. This patch
serializes those parameters into the generated lit config file so that
they are available to all configs.

Differential Revision: https://reviews.llvm.org/D105047
2021-06-29 10:51:42 -04:00
Amilendra Kodithuwakku 5636402bc0 [libcxx] Fix exception raised during downstream bare-metal libunwind tests
Fix for the following exception.

AttributeError: 'TestingConfig' object has no attribute 'target_triple'

Related revision: https://reviews.llvm.org/D102012

'TestingConfig' object has no attribute 'target_triple'

Reviewed By: #libunwind, miyuki, danielkiss, mstorsjo

Differential Revision: https://reviews.llvm.org/D103140
2021-06-16 13:35:36 +01:00
Louis Dionne 875ff8e059 [libc++] Enable tests for the experimental library by default
This matches the fact that we build the experimental library by default.
Otherwise, by default we'd be building the library but not testing it,
which is inconsistent.

Differential Revision: https://reviews.llvm.org/D102109
2021-06-02 18:39:27 -04:00
Louis Dionne 74d096e558 [libc++] Move handling of the target triple to the DSL
This fixes a long standing issue where the triple is not always set
consistently in all configurations. This change also moves the
back-deployment Lit features to using the proper target triple
instead of using something ad-hoc.

This will be necessary for using from scratch Lit configuration files
in both normal testing and back-deployment testing.

Differential Revision: https://reviews.llvm.org/D102012
2021-05-08 11:10:53 -04:00
Louis Dionne c06a8f9caa [libc++] Include <__config_site> from <__config>
Prior to this patch, we would generate a fancy <__config> header by
concatenating <__config_site> and <__config>. This complexifies the
build system and also increases the difference between what's tested
and what's actually installed.

This patch removes that complexity and instead simply installs <__config_site>
alongside the libc++ headers. <__config_site> is then included by <__config>,
which is much simpler. Doing this also opens the door to having different
<__config_site> headers depending on the target, which was impossible before.

It does change the workflow for testing header-only changes to libc++.
Previously, we would run `lit` against the headers in libcxx/include.
After this patch, we run it against a fake installation root of the
headers (containing a proper <__config_site> header). This makes use
closer to testing what we actually install, which is good, however it
does mean that we have to update that root before testing header changes.
Thus, we now need to run `ninja check-cxx-deps` before running `lit` by
hand.

Differential Revision: https://reviews.llvm.org/D97572
2021-03-30 14:06:11 -07:00
Louis Dionne 60ba1fefab [libc++/abi] Allow running back-deployment testing against libc++abi
Before this patch, we could only link against the back-deployment libc++abi
dylib. This patch allows linking against the just-built libc++abi, but
running against the back-deployment one -- just like we do for libc++.

Also, add XFAIL markup to flag expected errors.

Differential Revision: https://reviews.llvm.org/D91069
2021-03-01 12:13:03 -05:00
Ryan Prichard c82deed676 [libunwind] Unwind through aarch64/Linux sigreturn frame
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
2021-01-13 16:38:36 -08:00
Louis Dionne c1887e3f15 Revert "Allow running back-deployment testing against libc++abi"
This reverts commit 4d79ef814a, which broke a few build bots.
I'm reverting until I have time to investigate.
2020-11-06 17:26:42 -05:00
Louis Dionne 4d79ef814a Allow running back-deployment testing against libc++abi
Summary:
Before this patch, we could only link against the back-deployment libc++abi
dylib. This patch allows linking against the just-built libc++abi, but
running against the back-deployment one -- just like we do for libc++.

Also, add XFAIL markup to flag expected errors.
2020-11-06 08:12:46 -05:00
Daniel Kiss 05598e3d30 [libunwind] Fix linker flag handling in the tests.
--export-dynamic is not always available on all targets.
-funwind-tables was a duplicate in the lit.site.cfg.in.

Reviewed By: ldionne

Differential Revision: https://reviews.llvm.org/D90202
2020-10-29 14:02:44 +01:00
Louis Dionne 48e4b0fd3a [runtimes] Revert the libc++ __config_site change
This is a massive revert of the following commits (from most revent to oldest):

	2b9b7b5775.
	529ac33197
	28270234f1
	69c2087283
	b5aa67446e
	5d796645d6

After checking-in the __config_site change, a lot of things started breaking
due to widespread reliance on various aspects of libc++'s build, notably the
fact that we can include the headers from the source tree, but also reliance
on various "internal" CMake variables used by the runtimes build and compiler-rt.

These were unintended consequences of the change, and after two days, we
still haven't restored all the bots to being green. Instead, now that I
understand what specific areas this will blow up in, I should be able to
chop up the patch into smaller ones that are easier to digest.

See https://reviews.llvm.org/D89041 for more details on this adventure.
2020-10-23 09:41:48 -04:00
Louis Dionne 5d796645d6 [take 2] [libc++] Include <__config_site> from <__config>
Prior to this patch, we would generate a fancy <__config> header by
concatenating <__config_site> and <__config>. This complexifies the
build system and also increases the difference between what's tested
and what's actually installed.

This patch removes that complexity and instead simply installs <__config_site>
alongside the libc++ headers. <__config_site> is then included by <__config>,
which is much simpler. Doing this also opens the door to having different
<__config_site> headers depending on the target, which was impossible before.

It does change the workflow for testing header-only changes to libc++.
Previously, we would run `lit` against the headers in libcxx/include.
After this patch, we run it against a fake installation root of the
headers (containing a proper <__config_site> header). This makes use
closer to testing what we actually install, which is good, however it
does mean that we have to update that root before testing header changes.
Thus, we now need to run `ninja check-cxx-deps` before running `lit` by
hand.

This commit was originally applied in 1e46d1aa3 and reverted in eb60c487
because it broke the libc++abi and libunwind test suites. This has now
been fixed.

Differential Revision: https://reviews.llvm.org/D89041
2020-10-21 10:40:33 -04:00