Commit Graph

194 Commits

Author SHA1 Message Date
Martin Storsjö
ebde6fc23b [libcxxabi] Fix cmake order dependency wrt dllexporting
If LIBCXX_ENABLE_SHARED isn't explicitly set on the cmake command
line, isn't set in the cache, and the libcxxabi project is configured
before libcxx, then LIBCXX_ENABLE_SHARED isn't defined yet. Once
the libcxx cmake project has been parsed, LIBCXX_ENABLE_SHARED would
have been set to its default value of ON.

This makes sure that the symbols are properly dllexported in such
a configuration scenario.

Differential Revision: https://reviews.llvm.org/D120982
2022-03-07 15:36:04 -05:00
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
Louis Dionne
6dfdf79b8c [libc++abi] Install the libc++abi headers from libc++abi
libc++abi should be responsible for installing its own headers, it
doesn't make sense for libc++ to be responsible for it.

Differential Revision: https://reviews.llvm.org/D101458
2022-02-28 17:22:53 -05:00
Louis Dionne
2e3bb910e3 [runtimes] Move warning messages for FOO_SYSROOT & friends above their default value
Otherwise, the warnings always trigger.
2022-02-16 12:00:34 -05:00
Louis Dionne
641a141da1 [runtimes] Deprecate FOO_SYSROOT & friends
As suggested in https://reviews.llvm.org/D112155.

Differential Revision: https://reviews.llvm.org/D119836
2022-02-16 09:44:08 -05:00
Louis Dionne
6f17768e11 [runtimes] Remove support for standalone builds
Standalone build have been deprecated for some time now, so this
commit removes support for those builds entirely from libc++, libc++abi
and libunwind.

This, along with the removal of other legacy ways to build, will allow
for major build system simplifications.

Differential Revision: https://reviews.llvm.org/D119255
2022-02-09 08:55:31 -05:00
John Ericson
df31ff1b29 [cmake] Make include(GNUInstallDirs) always below project(..)
Its defaulting logic must go after `project(..)` to work correctly,  but `project(..)` is often in a standalone condition making this
awkward, since the rest of the condition code may also need GNUInstallDirs.

The good thing is there are the various standalone booleans, which I had missed before. This makes splitting the conditional blocks less awkward.

Reviewed By: arichardson, phosek, beanz, ldionne, #libunwind, #libc, #libc_abi

Differential Revision: https://reviews.llvm.org/D117639
2022-01-20 18:59:17 +00:00
John Ericson
429a717ea5 [cmake] Move HandleOutOfTreeLLVM to common cmake utils
This is better than libunwind and libcxxabi fishing it out of libcxx's
module directory.

It is done in prepartion for a better version of D117537 which deduplicates
CMake logic instead of just renaming to avoid a name clash.

Reviewed By: phosek, #libunwind, #libc_abi, Ericson2314

Differential Revision: https://reviews.llvm.org/D117617
2022-01-19 22:05:23 +00:00
John Ericson
f16a4a034a [libcxx][libcxxabi][libunwind][cmake] Use GNUInstallDirs to support custom installation dirs
I am breaking apart D99484 so the cause of build failures is easier to
understand.

Differential Revision: https://reviews.llvm.org/D117417
2022-01-18 06:44:57 +00:00
John Ericson
da77db58d7 Revert "[cmake] Use GNUInstallDirs to support custom installation dirs."
https://lab.llvm.org/buildbot/#/builders/46/builds/21146 Still have
this odd error, not sure how to reproduce, so I will just try breaking
up my patch.

This reverts commit 4a678f8072.
2022-01-16 05:48:30 +00:00
John Ericson
4a678f8072 [cmake] Use GNUInstallDirs to support custom installation dirs.
This is the original patch in my GNUInstallDirs series, now last to merge as the final piece!

It arose as a new draft of D28234. I initially did the unorthodox thing of pushing to that when I wasn't the original author, but since I ended up

 - Using `GNUInstallDirs`, rather than mimicking it, as the original author was hesitant to do but others requested.

 - Converting all the packages, not just LLVM, effecting many more projects than LLVM itself.

I figured it was time to make a new revision.

I have used this patch series (and many back-ports) as the basis of https://github.com/NixOS/nixpkgs/pull/111487 for my distro (NixOS), which was merged last spring (2021). It looked like people were generally on board in D28234, but I make note of this here in case extra motivation is useful.

---

As pointed out in the original issue, a central tension is that LLVM already has some partial support for these sorts of things. Variables like `COMPILER_RT_INSTALL_PATH` have already been dealt with. Variables like `LLVM_LIBDIR_SUFFIX` however, will require further work, so that we may use `CMAKE_INSTALL_LIBDIR`.

These remaining items will be addressed in further patches. What is here is now rote and so we should get it out of the way before dealing more intricately with the remainder.

Reviewed By: #libunwind, #libc, #libc_abi, compnerd

Differential Revision: https://reviews.llvm.org/D99484
2022-01-16 05:33:07 +00:00
John Ericson
6e52bfe09d Revert "[cmake] Use GNUInstallDirs to support custom installation dirs."
Sorry for the disruption, I will try again later.

This reverts commit efeb501970.
2022-01-15 07:35:02 +00:00
John Ericson
efeb501970 [cmake] Use GNUInstallDirs to support custom installation dirs.
This is the original patch in my GNUInstallDirs series, now last to merge as the final piece!

It arose as a new draft of D28234. I initially did the unorthodox thing of pushing to that when I wasn't the original author, but since I ended up

 - Using `GNUInstallDirs`, rather than mimicking it, as the original author was hesitant to do but others requested.

 - Converting all the packages, not just LLVM, effecting many more projects than LLVM itself.

I figured it was time to make a new revision.

I have used this patch series (and many back-ports) as the basis of https://github.com/NixOS/nixpkgs/pull/111487 for my distro (NixOS), which was merged last spring (2021). It looked like people were generally on board in D28234, but I make note of this here in case extra motivation is useful.

---

As pointed out in the original issue, a central tension is that LLVM already has some partial support for these sorts of things. Variables like `COMPILER_RT_INSTALL_PATH` have already been dealt with. Variables like `LLVM_LIBDIR_SUFFIX` however, will require further work, so that we may use `CMAKE_INSTALL_LIBDIR`.

These remaining items will be addressed in further patches. What is here is now rote and so we should get it out of the way before dealing more intricately with the remainder.

Reviewed By: #libunwind, #libc, #libc_abi, compnerd

Differential Revision: https://reviews.llvm.org/D99484
2022-01-15 01:08:35 +00:00
Muiez Ahmed
a1da73961d [SystemZ][z/OS] ASCII/EBCDIC support with no coexistence
The aim of this patch is to break up the larger patch (https://reviews.llvm.org/D111323) to be more upstream friendly. In particular, this patch adds the char encoding sensitive changes but does not use inline namespaces as before. The use of namespaces to build both versions of the library, and localization of error messages will follow in a subsequent patch.

Differential Revision: https://reviews.llvm.org/D114813
2022-01-14 11:37:09 -05:00
John Ericson
0a8d15ad55 [libc++][libc++abi][libunwind] Dedup install path var definitions
In D116873 I did this for libunwind prior to defining a new install path
variable. But I think the change is good on its own, and libc++{,abi}
could also use it.

libc++ needed the base header var defined above the conditional part to
use it for the prefi+ed headers in the non-target-specific case. For
consistency, I therefore put the unconditional ones above for all 3
libs, which is why I touched the libunwind code (seeing that it had the
core change already)

Reviewed By: phosek, #libunwind, #libc, #libc_abi, ldionne

Differential Revision: https://reviews.llvm.org/D116988
2022-01-11 18:24:50 +00:00
John Ericson
949bbd0a68 [CMake] Use LLVM_COMMON_CMAKE_UTILS in runtimes just for clarity
In D116472 we created conditionally defined variables for the tools to
unbreak the legacy build where they are in `llvm/tools`.

The runtimes are not tools, so that flexibility doesn't matter. Still,
it might be nice to define (unconditionally) and use the variable for
the runtimes simply to make the code a bit clearer and document what is
going on.

Also, consistently put project dirs at the beginning, not end of `CMAKE_MODULE_PATH`. This ensures they will properly shadow similarly named stuff that happens to be later on the path.

Reviewed By: mstorsjo, #libunwind, #libc, #libc_abi, ldionne

Differential Revision: https://reviews.llvm.org/D116477
2022-01-03 20:55:44 +00:00
Louis Dionne
dc1244dc4e [runtimes] Move WARNING to FATAL_ERROR for folks using FOO_BUILD_32_BITS 2021-12-01 12:57:30 -05:00
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
ea23cc7120 [libc++abi] Don't re-define _LIBCPP_HAS_NO_THREADS in single-threaded mode
Libc++ already defines the macro inside its __config_site header, so
libc++abi doesn't need to do it. Doing it just leads to -Wmacro-redefined
warnings when building libc++abi.
2021-11-17 10:59:39 -05:00
David Tenty
2b416b4647 [libcxx][CI][AIX] Switch to LLVM_ENABLE_RUNTIMES
and to the new `runtimes` top level CMakeLists.txt since the old path is now deprecated. This requires a slight adjustment of the libcxxabi CMake, since there are required macro definitions we previously got via the `llvm/CMakeList.txt` path.

Reviewed By: ldionne, #libc, #libc_abi

Differential Revision: https://reviews.llvm.org/D113403
2021-11-09 16:04:10 -05:00
Petr Hosek
22acda48ff [CMake] Cache the compiler-rt library search results
There's a lot of duplicated calls to find various compiler-rt libraries
from build of runtime libraries like libunwind, libc++, libc++abi and
compiler-rt. The compiler-rt helper module already implemented caching
for results avoid repeated Clang invocations.

This change moves the compiler-rt implementation into a shared location
and reuses it from other runtimes to reduce duplication and speed up
the build.

Differential Revision: https://reviews.llvm.org/D88458
2021-10-27 17:53:03 -07:00
Petr Hosek
ba4920e98e Revert "[CMake] Cache the compiler-rt library search results"
This reverts commit 0eed292fba, there
are compiler-rt build failures that appear to have been introduced
by this change.
2021-10-21 10:32:01 -07:00
Louis Dionne
72117f2ffe [runtimes] Properly handle the sysroot/triple/gcc-toolchain
In 395271a, I simplified how we handled the target triple for the
runtimes. However, in doing so, we stopped considering the default
in CMAKE_CXX_COMPILER_TARGET, so we'd use the LLVM_DEFAULT_TARGET_TRIPLE
(which is the host triple) even if CMAKE_CXX_COMPILER_TARGET was specified.
This commit fixes that problem and also refactors the code so that it's
easy to see what the default value is.

The fact that nobody seems to have been broken by this makes me think
that perhaps nobody is using CMAKE_CXX_COMPILER_TARGET to specify the
triple -- but it should still work.

Differential Revision: https://reviews.llvm.org/D111672
2021-10-21 10:06:11 -04:00
Petr Hosek
0eed292fba [CMake] Cache the compiler-rt library search results
There's a lot of duplicated calls to find various compiler-rt libraries
from build of runtime libraries like libunwind, libc++, libc++abi and
compiler-rt. The compiler-rt helper module already implemented caching
for results avoid repeated Clang invocations.

This change moves the compiler-rt implementation into a shared location
and reuses it from other runtimes to reduce duplication and speed up
the build.

Differential Revision: https://reviews.llvm.org/D88458
2021-10-18 14:44:07 -07:00
Louis Dionne
d1e0f02e0b [libc++abi][ci] Add a from-scratch config for libc++abi on Apple/system
I came across an issue where since we build the library for Apple with
the install name directory being /usr/lib, which means that if we don't
run the tests with DYLD_LIBRARY_PATH, we'll end up loading the
system-provided libc++abi when running the tests. That wreaks havoc.

Instead of fixing it in the legacy config file, this commit introduces
an Apple libc++abi config file that does the right thing.

Differential Revision: https://reviews.llvm.org/D111279
2021-10-13 08:07:40 -04:00
Louis Dionne
54a8a0d09a [runtimes] Allow FOO_TEST_CONFIG to be a relative path
That makes it possible to store that value in a CMake cache if needed.

Differential Revision: https://reviews.llvm.org/D110843
2021-10-05 19:45:50 -04:00
Martin Storsjö
c4e8a2136c [runtimes] Allow overriding where CMake installs RUNTIME type libraries (DLLs)
Differential Revision: https://reviews.llvm.org/D107892
2021-09-09 00:01:38 +03:00
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
a59165b017 [runtimes] Don't try passing --target flags to GCC
When a target triple is specified in CMake via XXX_TARGET_TRIPLE, we tried
passing the --target=<...> flag to the compiler. However, not all compilers
support that flag (e.g. GCC, which is not a cross-compiler). As a result,
setting e.g. LIBCXX_TARGET_TRIPLE=<host-triple> would end up trying to
pass --target=<host-triple> to GCC, which breaks everything because the
flag isn't even supported.

This commit only adds `--target=<...>` & friends to the flags if it is
supported by the compiler.

One could argue that it's confusing to pass LIBCXX_TARGET_TRIPLE=<...>
and have it be ignored. That's correct, and one possibility would be
to assert that the requested triple is the same as the host triple when
we know the compiler is unable to cross-compile. However, note that this
is a pre-existing issue (setting the TARGET_TRIPLE variable never had an
influence on the flags passed to the compiler), and also fixing that is
starting to look like reimplementing a lot of CMake logic that is already
handled with CMAKE_CXX_COMPILER_TARGET.

Differential Revision: https://reviews.llvm.org/D106082
2021-07-15 16:52:02 -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
5099e01568 [runtimes] Inherit the TARGET_TRIPLE that may be set by LLVM 2021-07-14 14:29:29 -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
John Ericson
1e03c37b97 Prepare Compiler-RT for GnuInstallDirs, matching libcxx, document all
This is a second attempt at D101497, which landed as
9a9bc76c0e but had to be reverted in
8cf7ddbdd4.

This issue was that in the case that `COMPILER_RT_INSTALL_PATH` is
empty, expressions like "${COMPILER_RT_INSTALL_PATH}/bin" evaluated to
"/bin" not "bin" as intended and as was originally.

One solution is to make `COMPILER_RT_INSTALL_PATH` always non-empty,
defaulting it to `CMAKE_INSTALL_PREFIX`. D99636 adopted that approach.
But, I think it is more ergonomic to allow those project-specific paths
to be relative the global ones. Also, making install paths absolute by
default inhibits the proper behavior of functions like
`GNUInstallDirs_get_absolute_install_dir` which make relative install
paths absolute in a more complicated way.

Given all this, I will define a function like the one asked for in
https://gitlab.kitware.com/cmake/cmake/-/issues/19568 (and needed for a
similar use-case).

---

Original message:

Instead of using `COMPILER_RT_INSTALL_PATH` through the CMake for
complier-rt, just use it to define variables for the subdirs which
themselves are used.

This preserves compatibility, but later on we might consider getting rid
of `COMPILER_RT_INSTALL_PATH` and just changing the defaults for the
subdir variables directly.

---

There was a seaming bug where the (non-Apple) per-target libdir was
`${target}` not `lib/${target}`. I suspect that has to do with the docs
on `COMPILER_RT_INSTALL_PATH` saying was the library dir when that's no
longer true, so I just went ahead and fixed it, allowing me to define
fewer and more sensible variables.

That last part should be the only behavior changes; everything else
should be a pure refactoring.

---

I added some documentation of these variables too. In particular, I
wanted to highlight the gotcha where `-DSomeCachePath=...` without the
`:PATH` will lead CMake to make the path absolute. See [1] for
discussion of the problem, and [2] for the brief official documentation
they added as a result.

[1]: https://cmake.org/pipermail/cmake/2015-March/060204.html

[2]: https://cmake.org/cmake/help/latest/manual/cmake.1.html#options

In 38b2dec37e the problem was somewhat
misidentified and so `:STRING` was used, but `:PATH` is better as it
sets the correct type from the get-go.

---

D99484 is the main thrust of the `GnuInstallDirs` work. Once this lands,
it should be feasible to follow both of these up with a simple patch for
compiler-rt analogous to the one for libcxx.

Reviewed By: phosek, #libc_abi, #libunwind

Differential Revision: https://reviews.llvm.org/D105765
2021-07-13 15:21:41 +00:00
Louis Dionne
a0ae3b0789 [libc++abi] Remove the LIBCXXABI_ENABLE_PIC option
Instead, people should be using CMAKE_POSITION_INDEPENDENT_CODE to control
whether they want to use PIC or not. We should try to avoid reinventing
the wheel whenever CMake natively supports something.

This makes libc++abi consistent with libc++ and libunwind.

Differential Revision: https://reviews.llvm.org/D103973
2021-06-10 12:26:31 -04:00
Shoaib Meenai
6c05f2dab3 [libcxxabi] Remove unnecessary define from build
Now that we're passing -D_LIBCPP_BUILDING_LIBRARY to the libc++abi
build, -D_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS is redundant
(fb3a00c327/libcxx/include/exception (L120-L121)
is the only use of _LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS in
libc++, and that conditional also checks for _LIBCPP_BUILDING_LIBRARY).

Reviewed By: #libc_abi, phosek

Differential Revision: https://reviews.llvm.org/D102372
2021-05-20 16:56:05 -07:00
Petr Hosek
f749550cfe [libcxx] Stop using use c++ subdirectory for libc++ library
The new layout more closely matches the layout used by other compilers.
This is only used when LLVM_ENABLE_PER_TARGET_RUNTIME_DIR is enabled.

Differential Revision: https://reviews.llvm.org/D100869
2021-04-21 15:39:03 -07:00
Petr Hosek
96d8c6b571 [CMake] Remove {LIBCXX,LIBCXXABI,LIBUNWIND}_INSTALL_PREFIX
These variables were introduced during early work on the runtimes build
but were obsoleted by {LIBCXX,LIBCXXABI,LIBUNWIND}_INSTALL_LIBRARY_DIR.

Differential Revision: https://reviews.llvm.org/D99697
2021-04-01 10:13:07 -07:00
Petr Hosek
1687f2bbe2 [libcxxabi] Use cxx-headers target to consume libcxx headers
Rather than including libc++ include dir, use the cxx-headers target.

Differential Revision: https://reviews.llvm.org/D98367
2021-03-26 13:27:51 -07:00
Petr Hosek
74ed5124ba Revert "[libcxxabi] Use cxx-headers target to consume libcxx headers"
This reverts commit 72728e1280
which broke libcxxabi tests under the runtimes build.
2021-03-25 01:50:11 -07:00
Petr Hosek
72728e1280 [libcxxabi] Use cxx-headers target to consume libcxx headers
Rather than including libc++ include dir, use the cxx-headers target.

Differential Revision: https://reviews.llvm.org/D98367
2021-03-23 12:25:30 -07:00
Markus Böck
05b3716ddb [libcxxabi] Add LIBCXXABI_HAS_WIN32_THREAD_API build option
A few files in libc++abi make use of libc++ headers and a few of those use threading primitives provided by libc++. Since libc++ has multiple threading APIs it may be necessary to override auto-detection.

This patch adds the LIBCXXABI_HAS_WIN32_THREAD_API which does roughly the same as LIBCXXABI_HAS_PTHREAD_API and the similarly named LIBCXX_HAS_WIN32_THREAD_API from libc++. Instead of using autodetection it will force the use of win32 threads instead of pthreads in headers included from libc++.

Without this patch, libc++abi may depend on pthreads if present on the users build environment, even if win32 threading was selected for libc++.

Differential revision: https://reviews.llvm.org/D98021
2021-03-05 15:30:13 +01:00
Marek Kurdej
5e7a93a954 [libc++] Set CMAKE_FOLDER. NFC.
* This variable populates the default value of FOLDER target property. It is used in some IDE's (e.g. MSVC) to group different targets together.
2021-01-25 09:51:16 +01:00
Dan Albert
866d480fe0 [libc++abi] Add an option to avoid demangling in terminate.
We've been using this patch in Android so we can avoid including the
demangler in libc++.so. It comes with a rather large cost in RSS and
isn't commonly needed.

Reviewed By: #libc_abi, compnerd

Differential Revision: https://reviews.llvm.org/D88189
2021-01-21 13:32:29 -08:00
Raul Tambre
480643a95c [CMake] Remove dead code setting policies to NEW
cmake_minimum_required(VERSION) calls cmake_policy(VERSION),
which sets all policies up to VERSION to NEW.
LLVM started requiring CMake 3.13 last year, so we can remove
a bunch of code setting policies prior to 3.13 to NEW as it
no longer has any effect.

Reviewed By: phosek, #libunwind, #libc, #libc_abi, ldionne

Differential Revision: https://reviews.llvm.org/D94374
2021-01-19 17:19:36 +02:00
Martin Storsjö
8a73aa8c4c [libcxx] [libcxxabi] Set flags for visibility when statically linking libcxxabi into libcxx for windows
Previously, these had to be set manually when building each of the
projects standalone, in order to get proper symbol visibility when
combining the two libraries.

Differential Revision: https://reviews.llvm.org/D90021
2020-11-03 17:13:48 +02:00
Martin Storsjö
9c30bafd59 [libcxxabi] Build all of libcxxabi with _LIBCPP_BUILDING_LIBRARY defined
Various definitions from libcxx need to be set in the same way
as if building libcxx itself.

Differential Revision: https://reviews.llvm.org/D90476
2020-11-03 09:32:52 +02:00
Louis Dionne
b888463f8d [libc++abi] Make sure we can run the tests in Standalone mode
The tests would previously fail if the `python` executable wasn't found,
because we were missing the mandatory find_package.
2020-10-26 14:26:44 -04:00
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
529ac33197 [libc++abi] Fix the standalone build after the __config_site change
In 5d796645, we stopped looking at the LIBCXXABI_LIBCXX_INCLUDES variable,
which broke users of the Standalone build. This patch reinstates that
variable, however it must point to the *installed* path of the libc++
headers, not the libc++ headers in the source tree (which has always
been the case, but wasn't enforced before).

If LIBCXXABI_LIBCXX_INCLUDES points to the libc++ headers in the source
tree, the `__config_site` header will fail to be found.
2020-10-22 19:17:20 -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