[libc++][hardening] Deprecate `_LIBCPP_ENABLE_ASSERTIONS`.

[var-const]

Summary

_LIBCPP_ENABLE_ASSERTIONS was used to enable the "safe" mode in
libc++. Libc++ now provides the hardened mode and the debug mode that
replace the safe mode.

For backward compatibility, enabling _LIBCPP_ENABLE_ASSERTIONS now
enables the hardened mode. Note that the hardened mode provides
a narrower set of checks than the previous "safe" mode (only
security-critical checks that are performant enough to be used in
production).

[ldionne]

libcxx/CMakeLists.txt

68

I would remove that option, since it's only used by vendors. I think this is what we want to do:

# TODO(LLVM 18): Remove this after branching for LLVM 17, this is a simple courtesy for vendors to be notified about this change.
if (LIBCXX_ENABLE_ASSERTIONS)
  message(FATAL_ERROR "LIBCXX_ENABLE_ASSERTIONS has been replaced by LIBCXX_HARDENING_MODE=hardened")
endif()

Then we also release note (for vendors) that we removed LIBCXX_ENABLE_ASSERTIONS.

The reason for the temporary FATAL_ERROR is that I want to avoid the case where a vendor is currently specifying LIBCXX_ENABLE_ASSERTIONS and then suddenly after this change they would build the library in unchecked mode, silently.

[ldionne]

libcxx/CMakeLists.txt

43

Also we should update the documentation and tests.

586–587

Let's remove LIBCXX_DEBUG_BUILD in a pre-requisite patch. I don't think that's needed anymore, since we use our own internal assertion mechanism.

I think the only place where you'll still want to have a similar check is in cxx_link_system_libraries where you can do something like

if (CMAKE_BUILD_TYPE STREQUAL "Debug")
  set(LIB_SUFFIX "d")
else()
  set(LIB_SUFFIX "")
endif()

libcxx/include/__assert

37–38

I think what I would do instead is this:

// Always define _LIBCPP_ASSERT to _LIBCPP_VERBOSE_ABORT(whatever)
// Always define _SOME_MACRO_THAT_MIGHT_EXPAND_TO_BUILTIN_ASSUME_ONE_DAY

#if _LIBCPP_ENABLE_HARDENED_MODE
    // TODO(hardening): Once we categorize assertions, only enable the ones that we really want here.
#  define _LIBCPP_ASSERT_UNCATEGORIZED(expression, message) _LIBCPP_ASSERT(expression, message)
#elif _LIBCPP_ENABLE_DEBUG_MODE
#  define _LIBCPP_ASSERT_UNCATEGORIZED(expression, message) _LIBCPP_ASSERT(expression, message)
#else
#  define _LIBCPP_ASSERT_UNCATEGORIZED(expression, message) _SOME_MACRO_THAT_MIGHT_EXPAND_TO_BUILTIN_ASSUME_ONE_DAY(...)
#endif

libcxx/include/__config

211–212

We can add a TODO(LLVM 18) here to remove this I guess.

216–218

_LIBCPP_ENABLE_ASSERTIONS_DEFAULT wouldn't be needed anymore since we're removing the CMake flag.

libcxx/utils/ci/run-buildbot

385

buildkite-pipeline.yml changes?

492

Let's make this apple-system-backdeployment-hardened-* and make the corresponding changes so this uses the hardened mode instead.

[var-const]

Address feedback

[var-const]

libcxx/CMakeLists.txt

586–587

Done: https://reviews.llvm.org/D155038

libcxx/include/__assert

37–38

Done. I moved the part that deals with _LIBCPP_ASSERT_UNCATEGORIZED to __config, please let me know what you think.

libcxx/utils/ci/run-buildbot

385

Thanks!

492

Done. Do we also need a new configuration for the debug mode?

[var-const]

Documentation changes.

[var-const]

Add a release note.

[ldionne]

libcxx/CMakeLists.txt

68

I think it would be easier to just remove the whole thing here, since we're not really retaining for backwards compat.

libcxx/cmake/caches/AIX.cmake

8–9

Since this is the default, I think I would just remove it. I think this was probably a leftover from copying the Apple cache, and the reason why it's in the Apple cache is that I wasn't sure what the default was (this went through various states, all of which were more complicated than the other).

libcxx/cmake/caches/Apple.cmake

4–5

I would remove since this is default.

16

This is a bit of a can of worms. I think I would avoid touching this in this patch and handle it as a cleanup later. While LIBCXX_ENABLE_ASSERTIONS is related to the hardened mode, LIBCXXABI_ENABLE_ASSERTIONS is not (for now) -- yes that is confusing.

libcxx/cmake/caches/FreeBSD.cmake

3–4

Same here.

libcxx/docs/HardenedMode.rst

22–23

25

27

31–32

34–35

41–42

libcxx/docs/ReleaseNotes.rst

94

TODO in a follow-up: Rename the document from HardenedMode.rst to Hardening.rst?

libcxx/docs/UsingLibcxx.rst

140–141

194

208–209

libcxx/include/__config

258

I think we might need to move the categorization to __assert, otherwise we're depending on _LIBCPP_ASSERT and _LIBCPP_ASSUME that are defined in __assert (and there's a circular dep if you try to include __assert from __config).

libcxx/utils/ci/buildkite-pipeline.yml

932–933

[ldionne]

libcxx/utils/libcxx/test/params.py

279

Existing tests that -D_LIBCPP_ENABLE_ASSERTIONS could now be moved to // UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode or similar.

[var-const]

libcxx/include/__config

258

I think it should be fine. This seems to work across all compilers (https://godbolt.org/z/o6dq7MaoT) and this part of the example in the Standard:

#define m(a)    a(w)
#define w       0,1
// (http://eel.is/c++draft/cpp.rescan)

also seems to confirm that we can rely on the other macro being substituted during the rescan.

[var-const]

Address feedback.

[var-const]

Fix the CI.

[ldionne]

Nice, thanks! This LGTM except for the _LIBCPP_DEBUG_STRICT_WEAK_ORDERING_CHECK test, which I have to investigate a bit more.

libcxx/include/__config

219–221

I think we should keep (or add) a test that you get the hardened mode when you define _LIBCPP_ENABLE_ASSERTIONS. If we mess that up, it could be very embarrassing in the upcoming release.

libcxx/test/libcxx/algorithms/alg.sorting/assert.sort.invalid_comparator.pass.cpp

13

This test isn't related to the legacy debug mode, so we don't want to disable it. I'm not sure what's the right call here cause I missed the review where they added -D_LIBCPP_DEBUG_STRICT_WEAK_ORDERING_CHECK, but naively I'd say that we should remove -D_LIBCPP_DEBUG_STRICT_WEAK_ORDERING_CHECK and instead add // UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode. I'll dig a bit more.

For now, to unblock you, I think you can just add

// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode

like you did everywhere around, and still keep ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DEBUG_STRICT_WEAK_ORDERING_CHECK below. I'll follow up on D150264 and we can fix this test separately.

libcxx/test/libcxx/assertions/assertions_disabled.pass.cpp

1

Can you confirm that we have tests to ensure that -D_LIBCPP_ENABLE_HARDENED_MODE=0 or -D_LIBCPP_ENABLE_DEBUG_MODE=0 has a similar effect?

libcxx/test/support/test.support/test_check_assertion.pass.cpp

10

Maybe

// UNSUPPORTED: c++03
// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode

since you do it consistently everywhere else?

[var-const]

Address feedback.

libcxx/include/__config

219–221

Added libcxx/test/libcxx/assertions/modes/enabling_assertions_enables_hardened_mode.pass.cp.

libcxx/test/libcxx/algorithms/alg.sorting/assert.sort.invalid_comparator.pass.cpp

9

Question unrelated to this patch: is this necessary? (Since the test is under test/libcxx)

13

Thanks!

libcxx/test/libcxx/assertions/assertions_disabled.pass.cpp

1

This should be covered by test/libcxx/assertions/modes/debug_mode_disabled_in_tu.pass.cpp and test/libcxx/assertions/modes/hardened_mode_disabled_in_tu.pass.cpp.

[var-const]

Fix the CI.

[var-const]

libcxx/docs/ReleaseNotes.rst

94

Done: e52f0e7746c8f2e8c0328054cc0934d4710e372d

[dblaikie]

Looks like this change didn't update https://github.com/llvm/llvm-project/commit/d8e9a1a12557cd5e80c3d713d9cbbba0f7406882 ? At least for me this seems to be causing hard failures when building like this:

CC=clang CXX=clang++ cmake -G Ninja -DLLVM_ENABLE_WERROR=true -DLIBCXX_ENABLE_WERROR=true -DLLVM_BUILD_EXAMPLES=true -DCMAKE_BUILD_TYPE=Debug -DLLVM_ENABLE_ASSERTIONS=true -DLLVM_USE_SPLIT_DWARF=true -DLLVM_OPTIMIZED_TABLEGEN=true  -DLLVM_ENABLE_LLD=true -DLLVM_ENABLE_PROJECTS='llvm;clang;clang-tools-extra;lld;lldb;cross-project-tests' -DLLVM_ENABLE_RUNTIMES='libcxxabi;libcxx;compiler-rt'  -DLLDB_ENABLE_PYTHON=On  ~/dev/llvm/src/llvm
ninja check-all

usr/local/google/home/blaikie/dev/llvm/build/default/./bin/clang++ --target=x86_64-unknown-linux-gnu -DLIBCXX_BUILDING_LIBCXXABI -D_GLIBCXX_ASSERTIONS -D_LIBCPP_BUILDING_LIBRARY -D_LIBCPP_ENABLE_ASSERTIONS -D_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER -D_LIBCPP_LINK_PTHREAD_LIB -D_LIBCPP_LINK_RT_LIB -D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/usr/local/google/home/blaikie/dev/llvm/src/libcxx/src -I/usr/local/google/home/blaikie/dev/llvm/build/default/include/c++/v1 -I/usr/local/google/home/blaikie/dev/llvm/build/default/include/x86_64-unknown-linux-gnu/c++/v1 -I/usr/local/google/home/blaikie/dev/llvm/src/libcxxabi/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -g -fPIC -gsplit-dwarf -faligned-allocation -nostdinc++ -fvisibility-inlines-hidden -fvisibility=hidden -Wall -Wextra -Wnewline-eof -Wshadow -Wwrite-strings -Wno-unused-parameter -Wno-long-long -Werror=return-type -Wextra-semi -Wundef -Wunused-template -Wformat-nonliteral -Wno-user-defined-literals -Wno-covered-switch-default -Wno-suggest-override -Werror -std=c++20 -MD -MT libcxx/src/CMakeFiles/cxx_shared.dir/new_handler.cpp.o -MF libcxx/src/CMakeFiles/cxx_shared.dir/new_handler.cpp.o.d -o libcxx/src/CMakeFiles/cxx_shared.dir/new_handler.cpp.o -c /usr/local/google/home/blaikie/dev/llvm/src/libcxx/src/new_handler.cpp
In file included from /usr/local/google/home/blaikie/dev/llvm/src/libcxx/src/new_handler.cpp:9:
In file included from /usr/local/google/home/blaikie/dev/llvm/build/default/include/c++/v1/new:89:
In file included from /usr/local/google/home/blaikie/dev/llvm/build/default/include/c++/v1/__assert:13:
/usr/local/google/home/blaikie/dev/llvm/build/default/include/c++/v1/__config:215:6: error: "_LIBCPP_ENABLE_ASSERTIONS is deprecated, please use _LIBCPP_ENABLE_HARDENED_MODE instead." [-Werror,-W#warnings]
  215 | #    warning "_LIBCPP_ENABLE_ASSERTIONS is deprecated, please use _LIBCPP_ENABLE_HARDENED_MODE instead."
      |      ^

is something in the way I'm doing this not supported? If not, how has this not impacted other people in the last few weeks?

[cjdb]

In D154997#4536344, @dblaikie wrote:

Looks like this change didn't update https://github.com/llvm/llvm-project/commit/d8e9a1a12557cd5e80c3d713d9cbbba0f7406882 ? At least for me this seems to be causing hard failures when building like this:

CC=clang CXX=clang++ cmake -G Ninja -DLLVM_ENABLE_WERROR=true -DLIBCXX_ENABLE_WERROR=true -DLLVM_BUILD_EXAMPLES=true -DCMAKE_BUILD_TYPE=Debug -DLLVM_ENABLE_ASSERTIONS=true -DLLVM_USE_SPLIT_DWARF=true -DLLVM_OPTIMIZED_TABLEGEN=true  -DLLVM_ENABLE_LLD=true -DLLVM_ENABLE_PROJECTS='llvm;clang;clang-tools-extra;lld;lldb;cross-project-tests' -DLLVM_ENABLE_RUNTIMES='libcxxabi;libcxx;compiler-rt'  -DLLDB_ENABLE_PYTHON=On  ~/dev/llvm/src/llvm
ninja check-all

usr/local/google/home/blaikie/dev/llvm/build/default/./bin/clang++ --target=x86_64-unknown-linux-gnu -DLIBCXX_BUILDING_LIBCXXABI -D_GLIBCXX_ASSERTIONS -D_LIBCPP_BUILDING_LIBRARY -D_LIBCPP_ENABLE_ASSERTIONS -D_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER -D_LIBCPP_LINK_PTHREAD_LIB -D_LIBCPP_LINK_RT_LIB -D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/usr/local/google/home/blaikie/dev/llvm/src/libcxx/src -I/usr/local/google/home/blaikie/dev/llvm/build/default/include/c++/v1 -I/usr/local/google/home/blaikie/dev/llvm/build/default/include/x86_64-unknown-linux-gnu/c++/v1 -I/usr/local/google/home/blaikie/dev/llvm/src/libcxxabi/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -g -fPIC -gsplit-dwarf -faligned-allocation -nostdinc++ -fvisibility-inlines-hidden -fvisibility=hidden -Wall -Wextra -Wnewline-eof -Wshadow -Wwrite-strings -Wno-unused-parameter -Wno-long-long -Werror=return-type -Wextra-semi -Wundef -Wunused-template -Wformat-nonliteral -Wno-user-defined-literals -Wno-covered-switch-default -Wno-suggest-override -Werror -std=c++20 -MD -MT libcxx/src/CMakeFiles/cxx_shared.dir/new_handler.cpp.o -MF libcxx/src/CMakeFiles/cxx_shared.dir/new_handler.cpp.o.d -o libcxx/src/CMakeFiles/cxx_shared.dir/new_handler.cpp.o -c /usr/local/google/home/blaikie/dev/llvm/src/libcxx/src/new_handler.cpp
In file included from /usr/local/google/home/blaikie/dev/llvm/src/libcxx/src/new_handler.cpp:9:
In file included from /usr/local/google/home/blaikie/dev/llvm/build/default/include/c++/v1/new:89:
In file included from /usr/local/google/home/blaikie/dev/llvm/build/default/include/c++/v1/__assert:13:
/usr/local/google/home/blaikie/dev/llvm/build/default/include/c++/v1/__config:215:6: error: "_LIBCPP_ENABLE_ASSERTIONS is deprecated, please use _LIBCPP_ENABLE_HARDENED_MODE instead." [-Werror,-W#warnings]
  215 | #    warning "_LIBCPP_ENABLE_ASSERTIONS is deprecated, please use _LIBCPP_ENABLE_HARDENED_MODE instead."
      |      ^

is something in the way I'm doing this not supported? If not, how has this not impacted other people in the last few weeks?

I also see this when building LLVM with libc++.

[var-const]

In D154997#4536344, @dblaikie wrote:

Looks like this change didn't update https://github.com/llvm/llvm-project/commit/d8e9a1a12557cd5e80c3d713d9cbbba0f7406882 ? At least for me this seems to be causing hard failures when building like this:

Thank you for the heads-up! I'm trying the command you posted locally, but yes, I'm pretty sure that HandleLLVMOptions.cmake needs to be updated like you mentioned. Not sure why this hasn't come up sooner -- perhaps other build configurations don't use -Werror?

I can work on the fix, or feel free to replace the _LIBCPP_ENABLE_ASSERTIONS macro with _LIBCPP_ENABLE_HARDENED_MODE if that unblocks you faster.

[var-const]

@dblaikie @cjdb Created https://reviews.llvm.org/D156377. I'm still waiting for my local build to finish (my machine is pretty slow, unfortunately, so this will take a while), but it should be the fix. Can you help me find a reviewer for this? Thanks!

[var-const]

Ok, I verified locally that the fix in https://reviews.llvm.org/D156377 makes the build command succeed. I'll land the fix once the CI is green and ask for a cherry-pick for the LLVM 17 release.

[dblaikie]

In D154997#4537052, @var-const wrote:

Ok, I verified locally that the fix in https://reviews.llvm.org/D156377 makes the build command succeed. I'll land the fix once the CI is green and ask for a cherry-pick for the LLVM 17 release.

Awesome - thanks for the fix!

(anyone have any idea why this issue wasn't discovered sooner? are other libc++ developers doing something different from what I did? @ldionne?)

[philnik]

In D154997#4537400, @dblaikie wrote:

In D154997#4537052, @var-const wrote:

Ok, I verified locally that the fix in https://reviews.llvm.org/D156377 makes the build command succeed. I'll land the fix once the CI is green and ask for a cherry-pick for the LLVM 17 release.

Awesome - thanks for the fix!

(anyone have any idea why this issue wasn't discovered sooner? are other libc++ developers doing something different from what I did? @ldionne?)

Most libc++ developers (maybe even all right now) don't compile their own toolchain, especially not with assertions enabled.

[var-const]

In D154997#4537400, @dblaikie wrote:

Awesome - thanks for the fix!

(anyone have any idea why this issue wasn't discovered sooner? are other libc++ developers doing something different from what I did? @ldionne?)

Louis is on vacation, but to echo what Nikolas said, libc++ developers normally don't build llvm or clang, just libc++ and a few closely related targets. Not sure why other people building LLVM haven't encountered this, but perhaps they either don't build libc++ and/or don't use -Werror?

[Mordante]

In D154997#4537400, @dblaikie wrote:

In D154997#4537052, @var-const wrote:

Ok, I verified locally that the fix in https://reviews.llvm.org/D156377 makes the build command succeed. I'll land the fix once the CI is green and ask for a cherry-pick for the LLVM 17 release.

Awesome - thanks for the fix!

(anyone have any idea why this issue wasn't discovered sooner? are other libc++ developers doing something different from what I did? @ldionne?)

Debian provides nightly builds of Clang so I don't build Clang myself. And it seems we don't test this in the CI.

[dblaikie]

In D154997#4537439, @philnik wrote:

Most libc++ developers (maybe even all right now) don't compile their own toolchain, especially not with assertions enabled.

In D154997#4537661, @var-const wrote:

Louis is on vacation, but to echo what Nikolas said, libc++ developers normally don't build llvm or clang, just libc++ and a few closely related targets. Not sure why other people building LLVM haven't encountered this, but perhaps they either don't build libc++ and/or don't use -Werror?

In D154997#4539515, @Mordante wrote:

Debian provides nightly builds of Clang so I don't build Clang myself. And it seems we don't test this in the CI.

Thanks for the perspectives - yeah, I guess as LLVM's gotten larger people have become more specialized/it's not uncommon to be just building one subproject like that. Surprised it didn't turn up on some buildbot then, I guess...

Thanks all!

[thakis]

We are currently shipping the old _LIBCPP_ENABLE_ASSERTION mode. Is there a list of checks that we'll lose when we switch to this new hardened mode?

Also, it's a bit unfortunate that the Windows build of libc++ got broken before this landed (by D153709) and only fixed after this landed (by D155185). That means we can't update to the revision before this change here, then turn switch to hardened mode independent of updating libc++, and then keep updating. It'd be nice to have a temporary opt-out to make it possible to update libc++ in one change and then switch to this new mode in a separate change without updating libc++.

Currently, we'd have to pull in over 100 libc++ revisions at once, including this change (which as far as I understand causes us to lose a not-further-described list of checks).

[thakis]

In D154997#4572972, @thakis wrote:

We are currently shipping the old _LIBCPP_ENABLE_ASSERTION mode. Is there a list of checks that we'll lose when we switch to this new hardened mode?

I tried looking at this, here's what I came up with: https://bugs.chromium.org/p/chromium/issues/detail?id=1465186#c3

In summary, if I understood correctly, most asserts got replaced with _LIBCPP_ASSERT_UNCATEGORIZED() which is disabled in hardened mode.

So to get what we had, we want to ship debug mode. However, debug mode also enables __debug_less and __debug_three_way_comp, and it comes with an ominous comment in __config that says that debug mode "may affect the complexity of algorithms" (which we don't want, and which I think currently also doesn't happen), and it sounds like it's something you don't consider to be shippable.

Maybe _LIBCPP_ASSERT_UNCATEGORIZED and friends could only be defined if they aren't already defined, then we could map all of them to _LIBCPP_ASSERT and not define _LIBCPP_ENABLE_DEBUG_MODE? Then I think we'd have what we used to have and what we currently ship.

Does that sound correct?

(For example, one thing that the old asserts caught and that our tests verify libc++ catches but which isn't caught in hardened mode is string_view(ptr, -1).)

[ldionne]

In D154997#4574222, @thakis wrote:

[...]

Maybe _LIBCPP_ASSERT_UNCATEGORIZED and friends could only be defined if they aren't already defined, then we could map all of them to _LIBCPP_ASSERT and not define _LIBCPP_ENABLE_DEBUG_MODE? Then I think we'd have what we used to have and what we currently ship.

Does that sound correct?

(For example, one thing that the old asserts caught and that our tests verify libc++ catches but which isn't caught in hardened mode is string_view(ptr, -1).)

Just to give an update, we talked about it with @var-const and @thakis just now and we plan to add a new mode that contains the barebones hardening assertions, and also other assertions that are not expensive but also not the strict minimum security-wise. That's the mode that Chromium would want to use, since it'd be very close to the old "safe" mode.

[var-const]

In D154997#4577893, @ldionne wrote:

In D154997#4574222, @thakis wrote:

[...]

Maybe _LIBCPP_ASSERT_UNCATEGORIZED and friends could only be defined if they aren't already defined, then we could map all of them to _LIBCPP_ASSERT and not define _LIBCPP_ENABLE_DEBUG_MODE? Then I think we'd have what we used to have and what we currently ship.

Does that sound correct?

(For example, one thing that the old asserts caught and that our tests verify libc++ catches but which isn't caught in hardened mode is string_view(ptr, -1).)

Just to give an update, we talked about it with @var-const and @thakis just now and we plan to add a new mode that contains the barebones hardening assertions, and also other assertions that are not expensive but also not the strict minimum security-wise. That's the mode that Chromium would want to use, since it'd be very close to the old "safe" mode.

@thakis @ldionne For easy reference, the patch that's intended to address this is https://reviews.llvm.org/D158823

libcxx/CMakeLists.txt

 if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" AND "${CMAKE_CXX_SIMULATE_ID}" STREQUAL "MSVC")
   message(STATUS "Configuring for clang-cl")
   set(LIBCXX_TARGETING_CLANG_CL ON)
 endif()
 
 if (MSVC)
   message(STATUS "Configuring for MSVC")
 endif()
 
 #===============================================================================
 # Setup CMake Options
 #===============================================================================
 include(CMakeDependentOption)
 include(HandleCompilerRT)
 
 # Basic options ---------------------------------------------------------------
-option(LIBCXX_ENABLE_ASSERTIONS
-  "Enable assertions inside the compiled library, and at the same time make it the
-   default when compiling user code. Note that assertions can be enabled or disabled
-   by users in their own code regardless of this option." OFF)
 option(LIBCXX_ENABLE_SHARED "Build libc++ as a shared library." ON)
 option(LIBCXX_ENABLE_STATIC "Build libc++ as a static library." ON)
 option(LIBCXX_ENABLE_FILESYSTEM
   "Whether to include support for parts of the library that rely on a filesystem being
    available on the platform. This includes things like most parts of <filesystem> and
    others like <fstream>" ON)
 option(LIBCXX_INCLUDE_TESTS "Build the libc++ tests." ${LLVM_INCLUDE_TESTS})
 set(LIBCXX_SUPPORTED_HARDENING_MODES unchecked hardened debug)
 set(LIBCXX_HARDENING_MODE "unchecked" CACHE STRING
   "Specify the default hardening mode to use. This mode will be used inside the
    compiled library and will be the default when compiling user code. Note that
    users can override this setting in their own code. This does not affect the
    ABI. Supported values are ${LIBCXX_SUPPORTED_HARDENING_MODES}.")
 if (NOT "${LIBCXX_HARDENING_MODE}" IN_LIST LIBCXX_SUPPORTED_HARDENING_MODES)
   message(FATAL_ERROR
     "Unsupported hardening mode: '${LIBCXX_HARDENING_MODE}'. Supported values are ${LIBCXX_SUPPORTED_HARDENING_MODES}.")
 endif()
 option(LIBCXX_ENABLE_RANDOM_DEVICE
   "Whether to include support for std::random_device in the library. Disabling
    this can be useful when building the library for platforms that don't have
    a source of randomness, such as some embedded platforms. When this is not
    supported, most of <random> will still be available, but std::random_device
    will not." ON)
 option(LIBCXX_ENABLE_LOCALIZATION
   "Whether to include support for localization in the library. Disabling
    localization can be useful when porting to platforms that don't support
if (LIBCXX_BUILD_EXTERNAL_THREAD_LIBRARY AND LIBCXX_ENABLE_SHARED)
   # Need to allow unresolved symbols if this is to work with shared library builds
   if (APPLE)
     add_link_flags("-undefined dynamic_lookup")
   else()
     # Relax this restriction from HandleLLVMOptions
     string(REPLACE "-Wl,-z,defs" "" CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS}")
   endif()
 endif()
 
 # Modules flags ===============================================================
 # FIXME The libc++ sources are fundamentally non-modular. They need special
 # versions of the headers in order to provide C++03 and legacy ABI definitions.
 # NOTE: The public headers can be used with modules in all other contexts.
 function(cxx_add_module_flags target)
   if (LLVM_ENABLE_MODULES)
     # Ignore that the rest of the modules flags are now unused.
     target_add_compile_flags_if_supported(${target} PUBLIC -Wno-unused-command-line-argument)
     target_compile_options(${target} PUBLIC -fno-modules)

 config_define_if(LIBCXX_HAS_MUSL_LIBC _LIBCPP_HAS_MUSL_LIBC)
 config_define_if(LIBCXX_NO_VCRUNTIME _LIBCPP_NO_VCRUNTIME)
 config_define_if_not(LIBCXX_ENABLE_FILESYSTEM _LIBCPP_HAS_NO_FILESYSTEM)
 config_define_if_not(LIBCXX_ENABLE_RANDOM_DEVICE _LIBCPP_HAS_NO_RANDOM_DEVICE)
 config_define_if_not(LIBCXX_ENABLE_LOCALIZATION _LIBCPP_HAS_NO_LOCALIZATION)
 config_define_if_not(LIBCXX_ENABLE_UNICODE _LIBCPP_HAS_NO_UNICODE)
 config_define_if_not(LIBCXX_ENABLE_WIDE_CHARACTERS _LIBCPP_HAS_NO_WIDE_CHARACTERS)
 config_define_if_not(LIBCXX_ENABLE_VENDOR_AVAILABILITY_ANNOTATIONS _LIBCPP_HAS_NO_VENDOR_AVAILABILITY_ANNOTATIONS)
-if (LIBCXX_ENABLE_ASSERTIONS)
-  config_define(1 _LIBCPP_ENABLE_ASSERTIONS_DEFAULT)
-else()
-  config_define(0 _LIBCPP_ENABLE_ASSERTIONS_DEFAULT)
-endif()
 if (LIBCXX_HARDENING_MODE STREQUAL "hardened")
   config_define(1 _LIBCPP_ENABLE_HARDENED_MODE_DEFAULT)
   config_define(0 _LIBCPP_ENABLE_DEBUG_MODE_DEFAULT)
 elseif (LIBCXX_HARDENING_MODE STREQUAL "debug")
   config_define(0 _LIBCPP_ENABLE_HARDENED_MODE_DEFAULT)
   config_define(1 _LIBCPP_ENABLE_DEBUG_MODE_DEFAULT)
 elseif (LIBCXX_HARDENING_MODE STREQUAL "unchecked")
   config_define(0 _LIBCPP_ENABLE_HARDENED_MODE_DEFAULT)
   config_define(0 _LIBCPP_ENABLE_DEBUG_MODE_DEFAULT)
 endif()
+# TODO(LLVM 18): Remove this after branching for LLVM 17, this is a simple
+# courtesy for vendors to be notified about this change.
+if (LIBCXX_ENABLE_ASSERTIONS)
+  message(FATAL_ERROR "LIBCXX_ENABLE_ASSERTIONS has been replaced by LIBCXX_HARDENING_MODE=hardened")
+endif()
 
 if (LIBCXX_PSTL_CPU_BACKEND STREQUAL "serial")
   config_define(1 _LIBCPP_PSTL_CPU_BACKEND_SERIAL)
 elseif(LIBCXX_PSTL_CPU_BACKEND STREQUAL "std_thread")
   config_define(1 _LIBCPP_PSTL_CPU_BACKEND_THREAD)
 elseif(LIBCXX_PSTL_CPU_BACKEND STREQUAL "libdispatch")
   config_define(1 _LIBCPP_PSTL_CPU_BACKEND_LIBDISPATCH)
 else()

libcxx/cmake/caches/AIX.cmake

 set(CMAKE_BUILD_TYPE Release CACHE STRING "")
 set(CMAKE_BUILD_WITH_INSTALL_RPATH ON CACHE BOOL "")
 set(CMAKE_C_FLAGS "-D__LIBC_NO_CPP_MATH_OVERLOADS__" CACHE STRING "")
 set(CMAKE_CXX_FLAGS "-D__LIBC_NO_CPP_MATH_OVERLOADS__" CACHE STRING "")
 set(CMAKE_SHARED_LINKER_FLAGS "-Wl,-G -Wl,-bcdtors:all:-2147483548:s" CACHE STRING "")
 set(CMAKE_AR "/usr/bin/ar" CACHE FILEPATH "")
 
 set(LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
-set(LIBCXX_ENABLE_ASSERTIONS OFF CACHE BOOL "")
 set(LIBCXX_ABI_VERSION "1" CACHE STRING "")
 set(LIBCXX_ENABLE_ABI_LINKER_SCRIPT OFF CACHE BOOL "")
 set(LIBCXX_ENABLE_SHARED ON CACHE BOOL "")
 set(LIBCXX_ENABLE_STATIC OFF CACHE BOOL "")
 set(LIBCXXABI_ENABLE_SHARED ON CACHE BOOL "")
 set(LIBCXXABI_ENABLE_STATIC OFF CACHE BOOL "")
 set(LIBCXX_CXX_ABI libcxxabi CACHE STRING "")
 set(LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
 set(LIBUNWIND_ENABLE_SHARED ON CACHE BOOL "")
 set(LIBUNWIND_ENABLE_STATIC OFF CACHE BOOL "")

libcxx/cmake/caches/Apple.cmake

 set(CMAKE_BUILD_TYPE MinSizeRel CACHE STRING "")
 set(CMAKE_POSITION_INDEPENDENT_CODE OFF CACHE BOOL "")
 
 set(LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
-set(LIBCXX_ENABLE_ASSERTIONS OFF CACHE BOOL "")
 set(LIBCXX_ABI_VERSION "1" CACHE STRING "")
 set(LIBCXX_ENABLE_STATIC ON CACHE BOOL "")
 set(LIBCXX_ENABLE_SHARED ON CACHE BOOL "")
 set(LIBCXX_CXX_ABI libcxxabi CACHE STRING "")
 set(LIBCXX_ENABLE_VENDOR_AVAILABILITY_ANNOTATIONS ON CACHE BOOL "")
 set(LIBCXX_PSTL_CPU_BACKEND libdispatch)
 
 set(LIBCXX_HERMETIC_STATIC_LIBRARY ON CACHE BOOL "")
 set(LIBCXXABI_HERMETIC_STATIC_LIBRARY ON CACHE BOOL "")
 
 set(LIBCXXABI_ENABLE_ASSERTIONS OFF CACHE BOOL "")
 set(LIBCXXABI_ENABLE_FORGIVING_DYNAMIC_CAST ON CACHE BOOL "")
 
 set(LIBCXX_TEST_CONFIG "apple-libc++-shared.cfg.in" CACHE STRING "")
 set(LIBCXXABI_TEST_CONFIG "apple-libc++abi-shared.cfg.in" CACHE STRING "")

libcxx/cmake/caches/FreeBSD.cmake

 set(CMAKE_BUILD_TYPE Release CACHE STRING "")
 set(CMAKE_POSITION_INDEPENDENT_CODE ON CACHE BOOL "")
 
-set(LIBCXX_ENABLE_ASSERTIONS OFF CACHE BOOL "")
 set(LIBCXX_ABI_VERSION "1" CACHE STRING "")
 set(LIBCXX_ENABLE_STATIC ON CACHE BOOL "")
 set(LIBCXX_ENABLE_SHARED ON CACHE BOOL "")
 set(LIBCXX_CXX_ABI libcxxrt CACHE STRING "")
 set(LIBCXX_ENABLE_NEW_DELETE_DEFINITIONS ON CACHE BOOL "")

libcxx/cmake/caches/Generic-assertions.cmake

-set(LIBCXX_ENABLE_ASSERTIONS ON CACHE BOOL "")
-set(LIBCXXABI_ENABLE_ASSERTIONS ON CACHE BOOL "")

libcxx/docs/BuildingLibcxx.rst

.. option:: LIBCXX_INSTALL_LIBRARY:BOOL
   Toggle the installation of the library portion of libc++.
 
 .. option:: LIBCXX_INSTALL_HEADERS:BOOL
 
   **Default**: ``ON``
 
   Toggle the installation of the libc++ headers.
 
-.. option:: LIBCXX_ENABLE_ASSERTIONS:BOOL
-
-  **Default**: ``OFF``
-
-  Build libc++ with assertions enabled in the compiled library, and enable assertions
-  by default when building user code as well. Assertions can be turned off by users
-  by defining ``_LIBCPP_ENABLE_ASSERTIONS=0``. For details, see
-  :ref:`the documentation <assertions-mode>`.
-
 .. option:: LIBCXX_ENABLE_SHARED:BOOL
 
   **Default**: ``ON``
 
   Build libc++ as a shared library. Either `LIBCXX_ENABLE_SHARED` or
   `LIBCXX_ENABLE_STATIC` has to be enabled.
 
 .. option:: LIBCXX_ENABLE_STATIC:BOOL

libcxx/docs/HardenedMode.rst

 undefined behavior caused by violating preconditions of the standard library.
 These assertions can be done with relatively little overhead in constant time
 and are intended to be used in production.
 
 In addition to the hardened mode, libc++ also provides the debug mode which
 contains all the checks from the hardened mode and additionally more expensive
 checks that may affect the complexity of algorithms. The debug mode is intended
 to be used for testing, not in production.
 
-Vendors can set the default hardened mode by using the ``LIBCXX_HARDENING_MODE``
-CMake variable. Setting ``LIBCXX_HARDENING_MODE`` to ``hardened`` enables the
-hardened mode, and similarly setting the variable to ``debug`` enables the debug
-mode. The default value is ``unchecked`` which doesn't enable the hardened mode.
-Users can control whether the hardened mode or the debug mode is enabled
-on a per translation unit basis by setting the ``_LIBCPP_ENABLE_HARDENED_MODE``
-or ``_LIBCPP_ENABLE_DEBUG_MODE`` macro to ``1``.
-
-The hardened mode requires ``LIBCXX_ENABLE_ASSERTIONS`` to work. If
-``LIBCXX_ENABLE_ASSERTIONS`` was not set explicitly, enabling the hardened mode
-(or the debug mode) will implicitly enable ``LIBCXX_ENABLE_ASSERTIONS``. If
-``LIBCXX_ENABLE_ASSERTIONS`` was explicitly disabled, this will effectively
-disable the hardened mode.
+Vendors can set the default hardening mode by using the
+``LIBCXX_HARDENING_MODE`` variable at CMake configuration time. Setting
+``LIBCXX_HARDENING_MODE`` to ``hardened`` enables the hardened mode, and
+similarly setting the variable to ``debug`` enables the debug mode. The default
+value is ``unchecked`` which doesn't enable any hardening.
+
+When hardening is enabled, the compiled library is built with the corresponding
+mode enabled, **and** user code will be built with the same mode enabled by
+default. If the mode is set to "unchecked" at the CMake configuration time, the
+compiled library will not contain any assertions and the default when building
+user code will be to have assertions disabled. As a user, you can consult your
+vendor to know which level of hardening is enabled by default.
+
+Furthermore, independently of any vendor-selected default, users can always
+control which level of hardening is enabled in their code by defining
+``_LIBCPP_ENABLE_HARDENED_MODE=0|1`` (or ``_LIBCPP_ENABLE_DEBUG_MODE=0|1``)
+before including any libc++ header (we recommend passing
+``-D_LIBCPP_ENABLE_HARDENED_MODE=X`` or ``-D_LIBCPP_ENABLE_DEBUG_MODE=X`` to the
+compiler). Note that if the compiled library was built by the vendor in the
+unchecked mode, functions compiled inside the static or shared library won't
+have any hardening enabled even if the user compiles with hardening enabled (the
+same is true for the inverse case where the static or shared library was
+compiled **with** hardening enabled but the user tries to disable it). However,
+most of the code in libc++ is in the headers, so the user-selected value for
+``_LIBCPP_ENABLE_HARDENED_MODE`` or ``_LIBCPP_ENABLE_DEBUG_MODE`` (if any) will
+usually be respected.
 
-Enabling the hardened mode (or the debug mode) has no impact on the ABI.
+Enabling hardening has no impact on the ABI.
 
 Iterator bounds checking
 ------------------------
 TODO(hardening)

libcxx/docs/ReleaseNotes.rst

- The library now provides a debug mode which is a superset of the hardened mode, additionally enabling more expensive
   release. Unlike the legacy debug mode, this doesn't affect the ABI and doesn't require locking. Vendors can configure
   whether the debug mode is enabled by default with the ``LIBCXX_HARDENING_MODE`` variable at CMake configuration time.
   Users can control whether the debug mode is enabled on a per translation unit basis using the
   ``-D_LIBCPP_ENABLE_DEBUG_MODE=1`` macro. See ``libcxx/docs/HardenedMode.rst`` for more details.
 
 Deprecations and Removals
 -------------------------
 
+- The "safe" mode is replaced by the hardened mode in this release. The ``LIBCXX_ENABLE_ASSERTIONS`` CMake variable is
+  deprecated and setting it will trigger an error; use ``LIBCXX_HARDENING_MODE`` instead. Similarly, the
+  ``_LIBCPP_ENABLE_ASSERTIONS`` macro is deprecated and setting it to ``1`` now enables the hardened mode. See
+  ``libcxx/docs/HardenedMode.rst`` for more details.
+
 - The legacy debug mode has been removed in this release. Setting the macro ``_LIBCPP_ENABLE_DEBUG_MODE`` to ``1`` now
   enables the new debug mode which is part of hardening (see the "Improvements and New Features" section above). The
   ``LIBCXX_ENABLE_DEBUG_MODE`` CMake variable has been removed. For additional context, refer to the `Discourse post
   <https://discourse.llvm.org/t/rfc-removing-the-legacy-debug-mode-from-libc/71026>`_.
 
 - The ``<experimental/coroutine>`` header has been removed in this release. The ``<coroutine>`` header
   has been shipping since LLVM 14, so the Coroutines TS implementation is being removed per our policy
   for removing TSes.

libcxx/docs/UsingLibcxx.rst

 IWYU, you should run the tool like so:
 
 .. code-block:: bash
 
   $ include-what-you-use -Xiwyu /path/to/libcxx/include/libcxx.imp file.cpp
 
 If you would prefer to not use that flag, then you can replace ``/path/to/include-what-you-use/share/libcxx.imp```
 file with the libc++-provided ``libcxx.imp`` file.
 
-.. _assertions-mode:
+.. _termination-handler:
 
-Enabling the "safe libc++" mode
-===============================
+Overriding the default termination handler
+==========================================
+
+When the library wants to terminate due to an unforeseen condition (such as a hardening assertion
+failure), the program is aborted through a special verbose termination function. The library provides
+a default function that prints an error message and calls ``std::abort()``. Note that this function is
+provided by the static or shared library, so it is only available when deploying to a platform where
+the compiled library is sufficiently recent. On older platforms, the program will terminate in an
+unspecified unsuccessful manner, but the quality of diagnostics won't be great.
 
-Libc++ contains a number of assertions whose goal is to catch undefined behavior in the
-library, usually caused by precondition violations. Those assertions do not aim to be
-exhaustive -- instead they aim to provide a good balance between safety and performance.
-In particular, these assertions do not change the complexity of algorithms. However, they
-might, in some cases, interfere with compiler optimizations.
-
-By default, these assertions are turned off. Vendors can decide to turn them on while building
-the compiled library by defining ``LIBCXX_ENABLE_ASSERTIONS=ON`` at CMake configuration time.
-When ``LIBCXX_ENABLE_ASSERTIONS`` is used, the compiled library will be built with assertions
-enabled, **and** user code will be built with assertions enabled by default. If
-``LIBCXX_ENABLE_ASSERTIONS=OFF`` at CMake configure time, the compiled library will not contain
-assertions and the default when building user code will be to have assertions disabled.
-As a user, you can consult your vendor to know whether assertions are enabled by default.
-
-Furthermore, independently of any vendor-selected default, users can always control whether
-assertions are enabled in their code by defining ``_LIBCPP_ENABLE_ASSERTIONS=0|1`` before
-including any libc++ header (we recommend passing ``-D_LIBCPP_ENABLE_ASSERTIONS=X`` to the
-compiler). Note that if the compiled library was built by the vendor without assertions,
-functions compiled inside the static or shared library won't have assertions enabled even
-if the user defines ``_LIBCPP_ENABLE_ASSERTIONS=1`` (the same is true for the inverse case
-where the static or shared library was compiled **with** assertions but the user tries to
-disable them). However, most of the code in libc++ is in the headers, so the user-selected
-value for ``_LIBCPP_ENABLE_ASSERTIONS`` (if any) will usually be respected.
-
-When an assertion fails, the program is aborted through a special verbose termination function. The
-library provides a default function that prints an error message and calls ``std::abort()``. Note
-that this function is provided by the static or shared library, so it is only available when deploying
-to a platform where the compiled library is sufficiently recent. On older platforms, the program will
-terminate in an unspecified unsuccessful manner, but the quality of diagnostics won't be great.
 However, users can also override that mechanism at two different levels. First, the mechanism can be
-overridden at compile-time by defining the ``_LIBCPP_VERBOSE_ABORT(format, args...)`` variadic macro.
+overridden at compile time by defining the ``_LIBCPP_VERBOSE_ABORT(format, args...)`` variadic macro.
 When that macro is defined, it will be called with a format string as the first argument, followed by
 a series of arguments to format using printf-style formatting. Compile-time customization may be
-interesting to get precise control over code generation, however it is also inconvenient to use in
+useful to get precise control over code generation, however it is also inconvenient to use in
 some cases. Indeed, compile-time customization of the verbose termination function requires that all
 translation units be compiled with a consistent definition for ``_LIBCPP_VERBOSE_ABORT`` to avoid ODR
 violations, which can add complexity in the build system of users.
 
 Otherwise, if compile-time customization is not necessary, link-time customization of the handler is also
 possible, similarly to how replacing ``operator new`` works. This mechanism trades off fine-grained control
-over the call site where the termination is initiated in exchange for more ergonomics. Link-time customization
-is done by simply defining the following function in exactly one translation unit of your program:
+over the call site where the termination is initiated in exchange for better ergonomics. Link-time
+customization is done by simply defining the following function in exactly one translation unit of your
+program:
 
 .. code-block:: cpp
 
   void __libcpp_verbose_abort(char const* format, ...)
 
 This mechanism is similar to how one can replace the default definition of ``operator new``
 and ``operator delete``. For example:
 
void std::__libcpp_verbose_abort(char const* format, ...) {
     std::abort();
   }
 
   // In HelloWorld.cpp
   #include <vector>
 
   int main() {
     std::vector<int> v;
-    int& x = v[0]; // Your termination function will be called here if _LIBCPP_ENABLE_ASSERTIONS=1
+    int& x = v[0]; // Your termination function will be called here if hardening is enabled.
   }
 
 Also note that the verbose termination function should never return. Since assertions in libc++
 catch undefined behavior, your code will proceed with undefined behavior if your function is called
 and does return.
 
 Furthermore, exceptions should not be thrown from the function. Indeed, many functions in the
 library are ``noexcept``, and any exception thrown from the termination function will result
 in ``std::terminate`` being called.
 
 Libc++ Configuration Macros
 ===========================
 
 Libc++ provides a number of configuration macros which can be used to enable
-or disable extended libc++ behavior, including enabling "debug mode" or
-thread safety annotations.
+or disable extended libc++ behavior, including enabling hardening or thread
+safety annotations.
 
 **_LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS**:
   This macro is used to enable -Wthread-safety annotations on libc++'s
   ``std::mutex`` and ``std::lock_guard``. By default, these annotations are
   disabled and must be manually enabled by the user.
 
+**_LIBCPP_ENABLE_HARDENED_MODE**:
+  This macro is used to enable the :ref:`hardened mode <using-hardened-mode>`.
+
+**_LIBCPP_ENABLE_DEBUG_MODE**:
+  This macro is used to enable the :ref:`debug mode <using-hardened-mode>`.
+
 **_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS**:
   This macro is used to disable all visibility annotations inside libc++.
   Defining this macro and then building libc++ with hidden visibility gives a
   build of libc++ which does not export any symbols, which can be useful when
   building statically for inclusion into another library.
 
 **_LIBCPP_DISABLE_ADDITIONAL_DIAGNOSTICS**:
   This macro disables the additional diagnostics generated by libc++ using the

libcxx/include/__assert

 
 #include <__config>
 #include <__verbose_abort>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
-#ifndef _LIBCPP_ENABLE_ASSERTIONS
-#  define _LIBCPP_ENABLE_ASSERTIONS _LIBCPP_ENABLE_ASSERTIONS_DEFAULT
-#endif
-
-#if _LIBCPP_ENABLE_ASSERTIONS != 0 && _LIBCPP_ENABLE_ASSERTIONS != 1
-#  error "_LIBCPP_ENABLE_ASSERTIONS must be set to 0 or 1"
-#endif
-
-#if _LIBCPP_ENABLE_ASSERTIONS
-#  define _LIBCPP_ASSERT(expression, message)                                                                          \
-    (__builtin_expect(static_cast<bool>(expression), 1)                                                                \
-         ? (void)0                                                                                                     \
-         : _LIBCPP_VERBOSE_ABORT(                                                                                      \
-               "%s:%d: assertion %s failed: %s\n", __builtin_FILE(), __builtin_LINE(), #expression, message))
+#define _LIBCPP_ASSERT(expression, message)                                                                            \
+  (__builtin_expect(static_cast<bool>(expression), 1)                                                                  \
+       ? (void)0                                                                                                       \
+       : _LIBCPP_VERBOSE_ABORT(                                                                                        \
+
 // TODO: __builtin_assume can currently inhibit optimizations. Until this has been fixed and we can add
 //       assumptions without a clear optimization intent, disable that to avoid worsening the code generation.
 //       See https://discourse.llvm.org/t/llvm-assume-blocks-optimization/71609 for a discussion.
-#elif 0 && __has_builtin(__builtin_assume)
-#  define _LIBCPP_ASSERT(expression, message)                                                                          \
+#if 0 && __has_builtin(__builtin_assume)
+#  define _LIBCPP_ASSUME(expression)                                                                                   \
     (_LIBCPP_DIAGNOSTIC_PUSH _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wassume")                                              \
          __builtin_assume(static_cast<bool>(expression)) _LIBCPP_DIAGNOSTIC_POP)
 #else
-#  define _LIBCPP_ASSERT(expression, message) ((void)0)
+#  define _LIBCPP_ASSUME(expression) ((void)0)
 #endif
 
-#define _LIBCPP_ASSERT_UNCATEGORIZED(expression, message) _LIBCPP_ASSERT(expression, message)
-
 #endif // _LIBCPP___ASSERT

libcxx/include/__config

 // - `string_view`;
 // - `array`.
 // #define _LIBCPP_ABI_BOUNDED_ITERATORS
 
 // } ABI
 
 // HARDENING {
 
+// TODO(hardening): remove this in LLVM 18.
+// This is for backward compatibility -- make enabling `_LIBCPP_ENABLE_ASSERTIONS` (which predates hardening modes)
+// equivalent to setting the hardened mode.
+#  ifdef _LIBCPP_ENABLE_ASSERTIONS
+#    warning "_LIBCPP_ENABLE_ASSERTIONS is deprecated, please use _LIBCPP_ENABLE_HARDENED_MODE instead."
+#    if _LIBCPP_ENABLE_ASSERTIONS != 0 && _LIBCPP_ENABLE_ASSERTIONS != 1
+#      error "_LIBCPP_ENABLE_ASSERTIONS must be set to 0 or 1"
+#    endif
+#    if _LIBCPP_ENABLE_ASSERTIONS
+#      define _LIBCPP_ENABLE_HARDENED_MODE 1
+#    endif
+#  endif
+
 // Enables the hardened mode which consists of all checks intended to be used in production. Hardened mode prioritizes
 // security-critical checks that can be done with relatively little overhead in constant time. Mutually exclusive with
 // `_LIBCPP_ENABLE_DEBUG_MODE`.
 //
 // #define _LIBCPP_ENABLE_HARDENED_MODE 1
 
 // Enables the debug mode which contains all the checks from the hardened mode and additionally more expensive checks
 // that may affect the complexity of algorithms. The debug mode is intended to be used for testing, not in production.

 #  if _LIBCPP_ENABLE_DEBUG_MODE != 0 && _LIBCPP_ENABLE_DEBUG_MODE != 1
 #    error "_LIBCPP_ENABLE_DEBUG_MODE must be set to 0 or 1."
 #  endif
 
 #  if _LIBCPP_ENABLE_HARDENED_MODE && _LIBCPP_ENABLE_DEBUG_MODE
 #    error "Only one of _LIBCPP_ENABLE_HARDENED_MODE and _LIBCPP_ENABLE_DEBUG_MODE can be enabled."
 #  endif
 
 // Hardened mode checks.
 #  if _LIBCPP_ENABLE_HARDENED_MODE
 
-// Automatically enable assertions in hardened mode (unless the user explicitly turned them off).
-#    ifndef _LIBCPP_ENABLE_ASSERTIONS
-#      define _LIBCPP_ENABLE_ASSERTIONS 1
-#    endif
-
+// TODO(hardening): Once we categorize assertions, only enable the ones that we really want here.
+#    define _LIBCPP_ASSERT_UNCATEGORIZED(expression, message) _LIBCPP_ASSERT(expression, message)
 // TODO(hardening): more checks to be added here...
 
 // Debug mode checks.
 #  elif _LIBCPP_ENABLE_DEBUG_MODE
 
-// Automatically enable assertions in debug mode (unless the user explicitly turned them off).
-#    ifndef _LIBCPP_ENABLE_ASSERTIONS
-#      define _LIBCPP_ENABLE_ASSERTIONS 1
-#    endif
-
+// TODO(hardening): Once we categorize assertions, only enable the ones that we really want here.
+#    define _LIBCPP_ASSERT_UNCATEGORIZED(expression, message) _LIBCPP_ASSERT(expression, message)
 // TODO(hardening): more checks to be added here...
 
 // Disable all checks if neither the hardened mode nor the debug mode is enabled.
 #  else
 
+#    define _LIBCPP_ASSERT_UNCATEGORIZED(expression, message) _LIBCPP_ASSUME(expression)
 // TODO: more checks to be added here...
 
 #  endif // _LIBCPP_ENABLE_HARDENED_MODE
 
 // } HARDENING
 
 #  define _LIBCPP_TOSTRING2(x) #x
 #  define _LIBCPP_TOSTRING(x) _LIBCPP_TOSTRING2(x)

libcxx/include/__config_site.in

 #cmakedefine _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS
 #cmakedefine _LIBCPP_HAS_NO_VENDOR_AVAILABILITY_ANNOTATIONS
 #cmakedefine _LIBCPP_NO_VCRUNTIME
 #cmakedefine _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION @_LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION@
 #cmakedefine _LIBCPP_HAS_NO_FILESYSTEM
 #cmakedefine _LIBCPP_HAS_NO_RANDOM_DEVICE
 #cmakedefine _LIBCPP_HAS_NO_LOCALIZATION
 #cmakedefine _LIBCPP_HAS_NO_WIDE_CHARACTERS
-#cmakedefine01 _LIBCPP_ENABLE_ASSERTIONS_DEFAULT
 
 // PSTL backends
 #cmakedefine _LIBCPP_PSTL_CPU_BACKEND_SERIAL
 #cmakedefine _LIBCPP_PSTL_CPU_BACKEND_THREAD
 #cmakedefine _LIBCPP_PSTL_CPU_BACKEND_LIBDISPATCH
 
 // Hardening.
 #cmakedefine01 _LIBCPP_ENABLE_HARDENED_MODE_DEFAULT

libcxx/test/CMakeLists.txt

 if (NOT LIBCXX_ENABLE_EXCEPTIONS)
   serialize_lit_param(enable_exceptions False)
 endif()
 
 if (NOT LIBCXX_ENABLE_RTTI)
   serialize_lit_param(enable_rtti False)
 endif()
 
-if (LIBCXX_ENABLE_ASSERTIONS)
-  serialize_lit_param(enable_assertions True)
-endif()
-
 serialize_lit_param(hardening_mode "\"${LIBCXX_HARDENING_MODE}\"")
 
 if (CMAKE_CXX_COMPILER_TARGET)
   serialize_lit_param(target_triple "\"${CMAKE_CXX_COMPILER_TARGET}\"")
 else()
   serialize_lit_param(target_triple "\"${LLVM_DEFAULT_TARGET_TRIPLE}\"")
 endif()
 

libcxx/test/libcxx/algorithms/alg.sorting/assert.min.max.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <algorithm>
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <algorithm>
 #include <array>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
   std::initializer_list<int> init_list{};
   TEST_LIBCPP_ASSERT_FAILURE(std::ranges::minmax(init_list),
                              "initializer_list has to contain at least one element");
 
   TEST_LIBCPP_ASSERT_FAILURE(std::ranges::minmax(std::array<int, 0>{}),
                              "range has to contain at least one element");
 
   return 0;
 }

libcxx/test/libcxx/algorithms/alg.sorting/assert.sort.invalid_comparator.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: stdlib=libc++
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !libcpp-has-legacy-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1 -D_LIBCPP_DEBUG_STRICT_WEAK_ORDERING_CHECK
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DEBUG_STRICT_WEAK_ORDERING_CHECK
 // When the debug mode is enabled, this test fails because we actually catch on the fly that the comparator is not
 // a strict-weak ordering before we catch that we'd dereference out-of-bounds inside std::sort, which leads to different
 // errors than the ones tested below.
 // XFAIL: libcpp-has-debug-mode
 
 // This test uses a specific combination of an invalid comparator and sequence of values to
 // ensure that our sorting functions do not go out-of-bounds and satisfy strict weak ordering in that case.
 // Instead, we should fail loud with an assertion. The specific issue we're looking for here is when the comparator

libcxx/test/libcxx/assertions/assertions_disabled.pass.cpp

-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// Test that _LIBCPP_ASSERT doesn't do anything when assertions are disabled.
-// We need to use -Wno-macro-redefined because the test suite defines
-// _LIBCPP_ENABLE_ASSERTIONS=1 under some configurations.
-
-// ADDITIONAL_COMPILE_FLAGS: -Wno-macro-redefined -D_LIBCPP_ENABLE_ASSERTIONS=0
-
-#include <cassert>
-
-bool executed_condition = false;
-bool f() { executed_condition = true; return false; }
-
-int main(int, char**) {
-  _LIBCPP_ASSERT(f(), "message"); // should not execute anything
-  assert(!executed_condition); // really make sure we did not execute anything at all
-  return 0;
-}

libcxx/test/libcxx/assertions/customize_verbose_abort.compile-time.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // This compile-time customization requires cross-file macros, which doesn't work with modules.
 // UNSUPPORTED: modules-build
 
 // Make sure that we can customize the verbose termination function at compile-time by
 // defining _LIBCPP_VERBOSE_ABORT ourselves. Note that this does not have any
 // deployment target requirements.
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1 -D_LIBCPP_VERBOSE_ABORT(...)=my_abort(__VA_ARGS__)
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_VERBOSE_ABORT(...)=my_abort(__VA_ARGS__)
 
 #include <cstdlib>
 
 void my_abort(char const*, ...) {
   std::exit(EXIT_SUCCESS);
 }
 
 int main(int, char**) {
   _LIBCPP_ASSERT(false, "message");
   return EXIT_FAILURE;
 }

libcxx/test/libcxx/assertions/customize_verbose_abort.link-time.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // Test that we can set a custom verbose termination function at link-time.
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
-
 // We flag uses of the verbose termination function in older dylibs at compile-time to avoid runtime
 // failures when back-deploying.
 // XFAIL: availability-verbose_abort-missing
 
 #include <cstdlib>
 
 void std::__libcpp_verbose_abort(char const*, ...) {
   std::exit(EXIT_SUCCESS);
 }
 
 int main(int, char**) {
   _LIBCPP_ASSERT(false, "message");
   return EXIT_FAILURE;
 }

libcxx/test/libcxx/assertions/default_verbose_abort.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // Test that the default verbose termination function aborts the program.
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
-
 #include <csignal>
 #include <cstdlib>
 
 void signal_handler(int signal) {
   if (signal == SIGABRT)
     std::_Exit(EXIT_SUCCESS);
   std::_Exit(EXIT_FAILURE);
 }
 
 int main(int, char**) {
   if (std::signal(SIGABRT, signal_handler) != SIG_ERR)
     _LIBCPP_ASSERT(false, "foo");
   return EXIT_FAILURE;
 }

libcxx/test/libcxx/assertions/deprecated-link-time-custom-handler.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // XFAIL: availability-verbose_abort-missing
 
 // Make sure that we still support _LIBCPP_AVAILABILITY_CUSTOM_VERBOSE_ABORT_PROVIDED for folks
 // who customize the verbose termination function at link-time in back-deployment environments.
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1 -D_LIBCPP_AVAILABILITY_CUSTOM_VERBOSE_ABORT_PROVIDED
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_AVAILABILITY_CUSTOM_VERBOSE_ABORT_PROVIDED
 
 // We emit a #warning about the deprecation of this setting, so make sure we don't turn that into an error.
 // ADDITIONAL_COMPILE_FLAGS: -Wno-error
 
 #include <cstdlib>
 
 void std::__libcpp_verbose_abort(char const*, ...) {
   std::exit(EXIT_SUCCESS);
 }
 
 int main(int, char**) {
   _LIBCPP_ASSERT(false, "message");
   return EXIT_FAILURE;
 }

libcxx/test/libcxx/assertions/modes/debug_no_assertions.pass.cpp

-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// Test that we can override whether assertions are enabled regardless of the hardening mode in use.
-
-// UNSUPPORTED: !libcpp-has-debug-mode
-// ADDITIONAL_COMPILE_FLAGS: -Wno-macro-redefined -D_LIBCPP_ENABLE_ASSERTIONS=0
-
-#include <cassert>
-
-int main(int, char**) {
-  _LIBCPP_ASSERT_UNCATEGORIZED(true, "Should not fire");
-  _LIBCPP_ASSERT_UNCATEGORIZED(false, "Also should not fire");
-
-  return 0;
-}

libcxx/test/libcxx/assertions/modes/hardened.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // This test ensures that assertions trigger without the user having to do anything when the hardened mode has been
 // enabled by default.
 
 // UNSUPPORTED: !libcpp-has-hardened-mode
 // `check_assertion.h` is only available starting from C++11.
 // UNSUPPORTED: c++03
 // `check_assertion.h` requires Unix headers.
 // REQUIRES: has-unix-headers
+// XFAIL: availability-verbose_abort-missing
 
 #include <cassert>
 #include "check_assertion.h"
 
 int main(int, char**) {
   _LIBCPP_ASSERT_UNCATEGORIZED(true, "Should not fire");
   TEST_LIBCPP_ASSERT_FAILURE([] {
     _LIBCPP_ASSERT_UNCATEGORIZED(false, "Should fire");
   }(), "Should fire");
 
   return 0;
 }

libcxx/test/libcxx/assertions/modes/hardened_no_assertions.pass.cpp

-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// Test that we can override whether assertions are enabled regardless of the hardening mode in use.
-
-// UNSUPPORTED: !libcpp-has-hardened-mode
-// ADDITIONAL_COMPILE_FLAGS: -Wno-macro-redefined -D_LIBCPP_ENABLE_ASSERTIONS=0
-
-#include <cassert>
-
-int main(int, char**) {
-  _LIBCPP_ASSERT_UNCATEGORIZED(true, "Should not fire");
-  _LIBCPP_ASSERT_UNCATEGORIZED(false, "Also should not fire");
-
-  return 0;
-}

libcxx/test/libcxx/assertions/modes/unchecked.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // This test checks that if no hardening mode is defined (i.e., in the unchecked mode), by default assertions aren't
 // triggered.
 
 // UNSUPPORTED: libcpp-has-hardened-mode, libcpp-has-debug-mode
 
 #include <cassert>
 
+bool executed_condition = false;
+bool f() { executed_condition = true; return false; }
+
 int main(int, char**) {
-  // TODO(hardening): remove the `#if` guard once `_LIBCPP_ENABLE_ASSERTIONS` no longer affects hardening modes.
-#if !_LIBCPP_ENABLE_ASSERTIONS
   _LIBCPP_ASSERT_UNCATEGORIZED(true, "Should not fire");
   _LIBCPP_ASSERT_UNCATEGORIZED(false, "Also should not fire");
-#endif
+  _LIBCPP_ASSERT_UNCATEGORIZED(f(), "Should not execute anything");
+  assert(!executed_condition); // Really make sure we did not execute anything.
 
   return 0;
 }

libcxx/test/libcxx/assertions/single_expression.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-// Make sure that _LIBCPP_ASSERT is a single expression. This is useful so we can use
-// it in places that require an expression, such as in a constructor initializer list.
-
-// RUN: %{build} -Wno-macro-redefined -D_LIBCPP_ENABLE_ASSERTIONS=1
-// RUN: %{run}
-
-// RUN: %{build} -Wno-macro-redefined -D_LIBCPP_ENABLE_ASSERTIONS=0
-// RUN: %{run}
-
-// RUN: %{build} -Wno-macro-redefined -D_LIBCPP_ENABLE_ASSERTIONS=0 -D_LIBCPP_ASSERTIONS_DISABLE_ASSUME
-// RUN: %{run}
+// Make sure that `_LIBCPP_ASSERT` and `_LIBCPP_ASSUME` are each a single expression.
+// This is useful so we can use them  in places that require an expression, such as
+// in a constructor initializer list.
 
 #include <__assert>
 #include <cassert>
 
 void f() {
   int i = (_LIBCPP_ASSERT(true, "message"), 3);
   assert(i == 3);
   return _LIBCPP_ASSERT(true, "message");
 }
 
+void g() {
+  int i = (_LIBCPP_ASSUME(true), 3);
+  assert(i == 3);
+  return _LIBCPP_ASSUME(true);
+}
+
 int main(int, char**) {
   f();
+  g();
   return 0;
 }

libcxx/test/libcxx/containers/sequences/array/array.zero/assert.back.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // test that array<T, 0>::back() triggers an assertion
 
 #include <array>
 
 #include "check_assertion.h"
 
 int main(int, char**) {

libcxx/test/libcxx/containers/sequences/array/array.zero/assert.front.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // test that array<T, 0>::back() triggers an assertion
 
 #include <array>
 
 #include "check_assertion.h"
 
 int main(int, char**) {

libcxx/test/libcxx/containers/sequences/array/array.zero/assert.subscript.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // test that array<T, 0>::operator[] triggers an assertion
 
 #include <array>
 
 #include "check_assertion.h"
 
 int main(int, char**) {

libcxx/test/libcxx/containers/sequences/deque/assert.pop_back.empty.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <deque>
 
 // pop_back() more than the number of elements in a deque
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <deque>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     std::deque<int> q;
     q.push_back(0);
     q.pop_back();
     TEST_LIBCPP_ASSERT_FAILURE(q.pop_back(), "deque::pop_back called on an empty deque");
 
     return 0;
 }

libcxx/test/libcxx/containers/sequences/list/list.modifiers/assert.erase_iter.end.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <list>
 
 // Call erase(const_iterator position) with end()
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <list>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     int a1[] = {1, 2, 3};
     std::list<int> l1(a1, a1+3);
     std::list<int>::const_iterator i = l1.end();
     TEST_LIBCPP_ASSERT_FAILURE(l1.erase(i), "list::erase(iterator) called with a non-dereferenceable iterator");
 
     return 0;
 }

libcxx/test/libcxx/containers/sequences/list/list.modifiers/assert.pop_back.empty.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <list>
 
 // void pop_back();
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <list>
 #include <cassert>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     int a[] = {1, 2, 3};

libcxx/test/libcxx/containers/sequences/vector/assert.back.empty.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <vector>
 
 // Call back() on empty container.
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <vector>
 #include <cassert>
 
 #include "check_assertion.h"
 #include "min_allocator.h"
 
 int main(int, char**) {

libcxx/test/libcxx/containers/sequences/vector/assert.cback.empty.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <vector>
 
 // Call back() on empty const container.
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <vector>
 
 #include "check_assertion.h"
 #include "min_allocator.h"
 
 int main(int, char**) {
   {

libcxx/test/libcxx/containers/sequences/vector/assert.cfront.empty.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <vector>
 
 // Call front() on empty const container.
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <vector>
 
 #include "check_assertion.h"
 #include "min_allocator.h"
 
 int main(int, char**) {
   {

libcxx/test/libcxx/containers/sequences/vector/assert.cindex.oob.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <vector>
 
 // Index const vector out of bounds.
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <vector>
 #include <cassert>
 
 #include "check_assertion.h"
 #include "min_allocator.h"
 
 int main(int, char**) {

libcxx/test/libcxx/containers/sequences/vector/assert.front.empty.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <vector>
 
 // Call front() on empty container.
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <vector>
 #include <cassert>
 
 #include "check_assertion.h"
 #include "min_allocator.h"
 
 int main(int, char**) {

libcxx/test/libcxx/containers/sequences/vector/assert.index.oob.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <vector>
 
 // Index vector out of bounds.
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <vector>
 #include <cassert>
 
 #include "check_assertion.h"
 #include "min_allocator.h"
 
 int main(int, char**) {

libcxx/test/libcxx/containers/sequences/vector/assert.pop_back.empty.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <vector>
 
 // pop_back() more than the number of elements in a vector
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <vector>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     std::vector<int> v;
     v.push_back(0);
     v.pop_back();
     TEST_LIBCPP_ASSERT_FAILURE(v.pop_back(), "vector::pop_back called on an empty vector");
 
     return 0;
 }

libcxx/test/libcxx/containers/unord/unord.map/assert.bucket.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <unordered_map>
 
 // size_type bucket(const key_type& __k) const;
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <unordered_map>
 #include <string>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     typedef std::unordered_map<int, std::string> C;
     C c;
     TEST_LIBCPP_ASSERT_FAILURE(c.bucket(3), "unordered container::bucket(key) called when bucket_count() == 0");
 
     return 0;
 }

libcxx/test/libcxx/containers/unord/unord.map/assert.bucket_size.pass.cpp

 // template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
 //           class Alloc = allocator<pair<const Key, T>>>
 // class unordered_map
 
 // size_type bucket_size(size_type n) const
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <unordered_map>
 #include <string>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     typedef std::unordered_map<int, std::string> C;
     C c;
     TEST_LIBCPP_ASSERT_FAILURE(c.bucket_size(3), "unordered container::bucket_size(n) called with n >= bucket_count()");
 
     return 0;
 }

libcxx/test/libcxx/containers/unord/unord.map/assert.max_load_factor.pass.cpp

 //           class Alloc = allocator<pair<const Key, T>>>
 // class unordered_map
 
 // float max_load_factor() const;
 // void max_load_factor(float mlf);
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <unordered_map>
 #include <string>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     typedef std::unordered_map<int, std::string> C;
     C c;
     TEST_LIBCPP_ASSERT_FAILURE(c.max_load_factor(0), "unordered container::max_load_factor(lf) called with lf <= 0");
 
     return 0;
 }

libcxx/test/libcxx/containers/unord/unord.multimap/assert.bucket.pass.cpp

 // template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
 //           class Alloc = allocator<pair<const Key, T>>>
 // class unordered_multimap
 
 // size_type bucket(const key_type& __k) const;
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <unordered_map>
 #include <string>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     typedef std::unordered_multimap<int, std::string> C;
     C c;
     TEST_LIBCPP_ASSERT_FAILURE(c.bucket(3), "unordered container::bucket(key) called when bucket_count() == 0");
 
     return 0;
 }

libcxx/test/libcxx/containers/unord/unord.multimap/assert.bucket_size.pass.cpp

 // template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
 //           class Alloc = allocator<pair<const Key, T>>>
 // class unordered_multimap
 
 // size_type bucket_size(size_type n) const
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <unordered_map>
 #include <string>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     typedef std::unordered_multimap<int, std::string> C;
     C c;
     TEST_LIBCPP_ASSERT_FAILURE(c.bucket_size(3), "unordered container::bucket_size(n) called with n >= bucket_count()");
 
     return 0;
 }

libcxx/test/libcxx/containers/unord/unord.multimap/assert.max_load_factor.pass.cpp

 //           class Alloc = allocator<pair<const Key, T>>>
 // class unordered_multimap
 
 // float max_load_factor() const;
 // void max_load_factor(float mlf);
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <unordered_map>
 #include <string>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     typedef std::unordered_multimap<int, std::string> C;
     C c;
     TEST_LIBCPP_ASSERT_FAILURE(c.max_load_factor(0), "unordered container::max_load_factor(lf) called with lf <= 0");
 
     return 0;
 }

libcxx/test/libcxx/containers/unord/unord.multiset/assert.bucket.pass.cpp

 // template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
 //           class Alloc = allocator<Value>>
 // class unordered_multiset
 
 // size_type bucket(const key_type& __k) const;
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <unordered_set>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     typedef std::unordered_multiset<int> C;
     C c;
     TEST_LIBCPP_ASSERT_FAILURE(c.bucket(3), "unordered container::bucket(key) called when bucket_count() == 0");
 
     return 0;
 }

libcxx/test/libcxx/containers/unord/unord.multiset/assert.bucket_size.pass.cpp

 // template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
 //           class Alloc = allocator<Value>>
 // class unordered_multiset
 
 // size_type bucket_size(size_type n) const
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <unordered_set>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     typedef std::unordered_multiset<int> C;
     C c;
     TEST_LIBCPP_ASSERT_FAILURE(c.bucket_size(3), "unordered container::bucket_size(n) called with n >= bucket_count()");
 
     return 0;
 }

libcxx/test/libcxx/containers/unord/unord.multiset/assert.max_load_factor.pass.cpp

 //           class Alloc = allocator<Value>>
 // class unordered_multiset
 
 // float max_load_factor() const;
 // void max_load_factor(float mlf);
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <unordered_set>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     typedef std::unordered_multiset<int> C;
     C c;
     TEST_LIBCPP_ASSERT_FAILURE(c.max_load_factor(0), "unordered container::max_load_factor(lf) called with lf <= 0");
 
     return 0;
 }

libcxx/test/libcxx/containers/unord/unord.set/assert.bucket.pass.cpp

 // template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
 //           class Alloc = allocator<Value>>
 // class unordered_set
 
 // size_type bucket(const key_type& __k) const;
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <unordered_set>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     typedef std::unordered_set<int> C;
     C c;
     TEST_LIBCPP_ASSERT_FAILURE(c.bucket(3), "unordered container::bucket(key) called when bucket_count() == 0");
 
     return 0;
 }

libcxx/test/libcxx/containers/unord/unord.set/assert.bucket_size.pass.cpp

 // template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
 //           class Alloc = allocator<Value>>
 // class unordered_set
 
 // size_type bucket_size(size_type n) const
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <unordered_set>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     typedef std::unordered_set<int> C;
     C c;
     TEST_LIBCPP_ASSERT_FAILURE(c.bucket_size(3), "unordered container::bucket_size(n) called with n >= bucket_count()");
 
     return 0;
 }

libcxx/test/libcxx/containers/unord/unord.set/assert.max_load_factor.pass.cpp

 //           class Alloc = allocator<Value>>
 // class unordered_set
 
 // float max_load_factor() const;
 // void max_load_factor(float mlf);
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <unordered_set>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     typedef std::unordered_set<int> C;
     C c;
     TEST_LIBCPP_ASSERT_FAILURE(c.max_load_factor(-0.5f),
                                "unordered container::max_load_factor(lf) called with lf <= 0");
 
     return 0;
 }

libcxx/test/libcxx/containers/views/views.span/span.cons/assert.iter_sent.pass.cpp

 // Check that we ensure `Extent == sent - it` and also that `[it, sent)` is a valid range.
 //
 //
 // constexpr span<T, dynamic_extent>::span(Iterator it, Sentinel sent);
 //
 // Check that we ensure that `[it, sent)` is a valid range.
 
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <array>
 #include <span>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     {

libcxx/test/libcxx/containers/views/views.span/span.cons/assert.iter_size.pass.cpp

 //
 // constexpr span<T, Extent>::span(Iterator, size_type);
 //
 // Check that the passed size is equal to the statically known extent.
 // Note that it doesn't make sense to validate the incoming size in the
 // dynamic_extent version.
 
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <array>
 #include <span>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     std::array<int, 3> array{0, 1, 2};

libcxx/test/libcxx/containers/views/views.span/span.cons/assert.other_span.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // <span>
 //
 // constexpr span<T, Extent>::span(const span<U, dynamic_extent>& other);
 //
 // Check that we ensure `other.size() == Extent`.
 
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <array>
 #include <span>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     std::array<int, 3> array{0, 1, 2};
     std::span<int> other(array.data(), 3);
 
     auto invalid_source = [&] { std::span<int, 2> const s(other); (void)s; };
     TEST_LIBCPP_ASSERT_FAILURE(invalid_source(), "size mismatch in span's constructor (other span)");
 
     return 0;
 }

libcxx/test/libcxx/containers/views/views.span/span.cons/assert.range.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // <span>
 //
 // constexpr span<T, Extent>::span(Range&& r);
 //
 // Check that we ensure `size(r) == Extent`.
 
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <span>
 #include <vector>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     std::vector<int> vec{0, 1, 2}; // must use std::vector instead of std::array, because std::span has a special constructor from std::array
 
     auto invalid_size = [&] { std::span<int, 2> const s(vec); (void)s; };
     TEST_LIBCPP_ASSERT_FAILURE(invalid_size(), "size mismatch in span's constructor (range)");
 
     return 0;
 }

libcxx/test/libcxx/containers/views/views.span/span.elem/assert.back.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // <span>
 //
 // constexpr reference back() const noexcept;
 
 // Make sure that accessing a span out-of-bounds triggers an assertion.
 
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <array>
 #include <span>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     {

libcxx/test/libcxx/containers/views/views.span/span.elem/assert.front.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // <span>
 //
 // constexpr reference front() const noexcept;
 
 // Make sure that accessing a span out-of-bounds triggers an assertion.
 
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <array>
 #include <span>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     {

libcxx/test/libcxx/containers/views/views.span/span.elem/assert.op_idx.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // <span>
 //
 // constexpr reference operator[](size_type idx) const;
 
 // Make sure that accessing a span out-of-bounds triggers an assertion.
 
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <array>
 #include <span>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     {

libcxx/test/libcxx/containers/views/views.span/span.sub/assert.first.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // <span>
 //
 // constexpr span<element_type, dynamic_extent> first(size_type count) const;
 
 // Make sure that creating a sub-span with an incorrect number of elements triggers an assertion.
 
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <array>
 #include <span>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     {

libcxx/test/libcxx/containers/views/views.span/span.sub/assert.last.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // <span>
 //
 // constexpr span<element_type, dynamic_extent> last(size_type count) const;
 
 // Make sure that creating a sub-span with an incorrect number of elements triggers an assertion.
 
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <array>
 #include <span>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     {

libcxx/test/libcxx/containers/views/views.span/span.sub/assert.subspan.pass.cpp

 // constexpr span<element_type, dynamic_extent> subspan(
 //   size_type offset, size_type count = dynamic_extent) const;
 //
 // Requires: offset <= size() && (count == dynamic_extent || count <= size() - offset)
 
 // Make sure that creating a sub-span with an incorrect number of elements triggers an assertion.
 
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <array>
 #include <span>
 #include <cstddef>
 
 #include "check_assertion.h"
 
 int main(int, char**) {

libcxx/test/libcxx/debug/debug.assertions-enabled.compile.pass.cpp

-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// This test ensures that assertions are enabled by default when the debug mode is enabled.
-
-// REQUIRES: libcpp-has-legacy-debug-mode
-
-#include <version>
-
-#if !defined(_LIBCPP_ENABLE_ASSERTIONS) || _LIBCPP_ENABLE_ASSERTIONS == 0
-#   error "Assertions should be enabled automatically when the debug mode is enabled"
-#endif

libcxx/test/libcxx/experimental/memory/memory.polymorphic.allocator.class/memory.polymorphic.allocator.mem/assert.deallocate.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <experimental/memory_resource>
 
 // template <class T> class polymorphic_allocator
 
 // T* polymorphic_allocator<T>::deallocate(T*, size_t size)
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
-
 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
 
 #include <experimental/memory_resource>
 #include <type_traits>
 #include <cassert>
 
 #include "check_assertion.h"
 #include "test_memory_resource.h"

libcxx/test/libcxx/experimental/memory/memory.resource.adaptor/memory.resource.adaptor.mem/assert.deallocate.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <experimental/memory_resource>
 
 // template <class T> class polymorphic_allocator
 
 // T* polymorphic_allocator<T>::deallocate(T*, size_t size)
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
-
 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
 
 #include <experimental/memory_resource>
 #include <type_traits>
 #include <cassert>
 
 #include "check_assertion.h"
 #include "test_memory_resource.h"

libcxx/test/libcxx/input.output/filesystems/class.path/path.itr/assert.iterator.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <filesystem>
 
 // class path
 
 #include "filesystem_include.h"
 #include <iterator>
 #include <type_traits>

libcxx/test/libcxx/iterators/assert.advance.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <list>
 
 // Call advance(non-bidi iterator, -1)
 
 #include <iterator>
 
 #include "check_assertion.h"

libcxx/test/libcxx/iterators/assert.next.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
-// UNSUPPORTED: c++03
+// UNSUPPORTED: c++03, !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <list>
 
 // Call next(non-bidi iterator, -1)
 
 #include <iterator>
 
 #include "check_assertion.h"

libcxx/test/libcxx/iterators/assert.prev.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <list>
 
 // Call prev(forward_iterator, -1)
 
 #include <iterator>
 
 #include "check_assertion.h"

libcxx/test/libcxx/iterators/bounded_iter/dereference.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // template <class _Iterator>
 // struct __bounded_iter;
 //
 // Dereference and indexing operators
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <iterator>
 
 #include "check_assertion.h"
 #include "test_iterators.h"
 #include "test_macros.h"
 
 struct Foo {

libcxx/test/libcxx/ranges/range.adaptors/range.drop.while/assert.begin.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <ranges>
 
 // Call begin() on drop_while_view with empty predicate
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 // UNSUPPORTED: no-exceptions
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <ranges>
 
 #include "check_assertion.h"
 
 struct Exception {};
 struct ThrowOnCopyPred {
   ThrowOnCopyPred() = default;

libcxx/test/libcxx/ranges/range.adaptors/range.lazy.split/range.lazy.split.inner/assert.equal.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
-// UNSUPPORTED: c++03, c++11, c++14, c++17, !libcpp-has-legacy-debug-mode
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
+// XFAIL: availability-verbose_abort-missing
 
 // <ranges>
 
 // friend constexpr bool operator==(const inner-iterator& x, default_sentinel_t);
 //
 // Can't compare a default-constructed `inner-iterator` with the default sentinel.
 
 #include <ranges>

libcxx/test/libcxx/ranges/range.adaptors/range.lazy.split/range.lazy.split.outer/assert.equal.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
-// UNSUPPORTED: c++03, c++11, c++14, c++17, !libcpp-has-legacy-debug-mode
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
+// XFAIL: availability-verbose_abort-missing
 
 // <ranges>
 
 // friend constexpr bool operator==(const inner-iterator& x, default_sentinel_t);
 //
 // Can't compare a default-constructed `inner-iterator` with the default sentinel.
 
 #include <ranges>

libcxx/test/libcxx/strings/basic.string/string.access/assert.back.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <string>
 
 // Call back() on empty container.
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <string>
 
 #include "check_assertion.h"
 #include "min_allocator.h"
 
 int main(int, char**) {
     {

libcxx/test/libcxx/strings/basic.string/string.access/assert.cback.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <string>
 
 // Call back() on empty const container.
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <string>
 
 #include "check_assertion.h"
 #include "min_allocator.h"
 
 int main(int, char**) {
     {

libcxx/test/libcxx/strings/basic.string/string.access/assert.cfront.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <string>
 
 // Call front() on empty const container.
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <string>
 
 #include "check_assertion.h"
 #include "min_allocator.h"
 
 int main(int, char**) {
   {

libcxx/test/libcxx/strings/basic.string/string.access/assert.cindex.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <string>
 
 // Index const string out of bounds.
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <string>
 #include <cassert>
 
 #include "check_assertion.h"
 #include "min_allocator.h"
 
 int main(int, char**) {

libcxx/test/libcxx/strings/basic.string/string.access/assert.front.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <string>
 
 // Call front() on empty container.
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <string>
 #include <cassert>
 
 #include "check_assertion.h"
 #include "min_allocator.h"
 
 int main(int, char**) {

libcxx/test/libcxx/strings/basic.string/string.access/assert.index.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <string>
 
 // Index string out of bounds.
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <string>
 #include <cassert>
 
 #include "check_assertion.h"
 #include "min_allocator.h"
 
 int main(int, char**) {

libcxx/test/libcxx/strings/basic.string/string.modifiers/assert.erase_iter.null.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <string>
 
 // Call erase(const_iterator position) with end()
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <string>
 
 #include "check_assertion.h"
 #include "min_allocator.h"
 
 int main(int, char**) {
   {

libcxx/test/libcxx/strings/basic.string/string.modifiers/assert.pop_back.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <string>
 
 // void pop_back();
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <string>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     std::string s;
     TEST_LIBCPP_ASSERT_FAILURE(s.pop_back(), "string::pop_back(): string is already empty");
 
     return 0;
 }

libcxx/test/libcxx/strings/string.view/assert.ctor.length.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 
 // UNSUPPORTED: c++03, c++11
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // Construct a string_view from an invalid length
 // constexpr basic_string_view( const _CharT* s, size_type len )
 
 #include <string_view>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
   char c = 0;
   TEST_LIBCPP_ASSERT_FAILURE(
       std::string_view(&c, -1), "string_view::string_view(_CharT *, size_t): length does not fit in difference_type");
   return 0;
 }

libcxx/test/libcxx/strings/string.view/assert.ctor.pointer.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
-// UNSUPPORTED: c++11, c++14
-
-// UNSUPPORTED: c++03
+// UNSUPPORTED: c++03, c++11, c++14
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // Construct a string_view from a null pointer
 // constexpr basic_string_view( const CharT* s );
 
 #include <string_view>
 
 #include "check_assertion.h"
 

libcxx/test/libcxx/thread/futures/futures.promise/assert.set_exception.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, no-threads
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <future>
 
 // class promise<R>
 
 // void set_exception(exception_ptr p);
 // Test that a null exception_ptr is diagnosed.
 

libcxx/test/libcxx/thread/futures/futures.promise/assert.set_exception_at_thread_exit.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, no-threads
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <future>
 
 // class promise<R>
 
 // void set_exception_on_thread_exit(exception_ptr p);
 // Test that a null exception_ptr is diagnosed.
 

libcxx/test/libcxx/thread/thread.latch/assert.arrive_and_wait.pass.cpp

 
 // class latch;
 
 // void arrive_and_wait(ptrdiff_t __update = 1);
 
 // Make sure that calling arrive_and_wait with a negative value triggers an assertion.
 
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <latch>
 
 #include "check_assertion.h"
 
 int main(int, char **) {
   {
     std::latch l(5);
 
     TEST_LIBCPP_ASSERT_FAILURE(
         l.arrive_and_wait(-10),
         "latch::arrive_and_wait called with a negative value");
   }
 
   return 0;
 }

libcxx/test/libcxx/thread/thread.latch/assert.count_down.pass.cpp

 // class latch;
 
 // void count_down(ptrdiff_t __update = 1);
 
 // Make sure that calling count_down with a negative value or a value
 // higher than the internal counter triggers an assertion.
 
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <latch>
 
 #include "check_assertion.h"
 
 int main(int, char **) {
   {
     std::latch l(5);

libcxx/test/libcxx/thread/thread.latch/assert.ctor.pass.cpp

 
 // class latch;
 
 // constexpr explicit latch(ptrdiff_t __expected);
 
 // Make sure that calling latch with a negative value triggers an assertion
 
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <latch>
 
 #include "check_assertion.h"
 
 int main(int, char **) {
   {
     TEST_LIBCPP_ASSERT_FAILURE([]{ std::latch l(-1); }(),

libcxx/test/libcxx/utilities/assert.exception_guard.no_exceptions.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03
-
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -fno-exceptions -D_LIBCPP_ENABLE_ASSERTIONS=1
-
+// ADDITIONAL_COMPILE_FLAGS: -fno-exceptions
 // ADDITIONAL_COMPILE_FLAGS: -Wno-private-header
 
 #include <__utility/exception_guard.h>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
   TEST_LIBCPP_ASSERT_FAILURE(
       std::__make_exception_guard([] {}), "__exception_guard not completed with exceptions disabled");
 }

libcxx/test/libcxx/utilities/expected/expected.expected/assert.arrow.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // constexpr const T* operator->() const noexcept;
 // constexpr T* operator->() noexcept;
 //
 // Preconditions: has_value() is true.
 
 #include <expected>
 #include <utility>

libcxx/test/libcxx/utilities/expected/expected.expected/assert.deref.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // constexpr const T& operator*() const & noexcept;
 // constexpr T& operator*() & noexcept;
 // constexpr T&& operator*() && noexcept;
 // constexpr const T&& operator*() const && noexcept;
 //
 // Preconditions: has_value() is true.
 

libcxx/test/libcxx/utilities/expected/expected.expected/assert.error.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // constexpr const E& error() const & noexcept;
 // constexpr E& error() & noexcept;
 // constexpr E&& error() && noexcept;
 // constexpr const E&& error() const && noexcept;
 //
 // Preconditions: has_value() is false.
 

libcxx/test/libcxx/utilities/expected/expected.void/assert.deref.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // constexpr void operator*() const noexcept;
 //
 // Preconditions: has_value() is true.
 
 #include <expected>
 #include <utility>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
   std::expected<void, int> e{std::unexpect, 5};
   TEST_LIBCPP_ASSERT_FAILURE(*e, "expected::operator* requires the expected to contain a value");
 
   return 0;
 }

libcxx/test/libcxx/utilities/expected/expected.void/assert.error.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // constexpr const E& error() const & noexcept;
 // constexpr E& error() & noexcept;
 // constexpr E&& error() && noexcept;
 // constexpr const E&& error() const && noexcept;
 //
 // Preconditions: has_value() is false.
 

libcxx/test/libcxx/utilities/optional/optional.object/optional.object.observe/assert.dereference.pass.cpp

 
 // constexpr T& optional<T>::operator*() &;
 // constexpr T&& optional<T>::operator*() &&;
 // constexpr const T& optional<T>::operator*() const &;
 // constexpr T&& optional<T>::operator*() const &&;
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <optional>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     // &
     {

libcxx/test/libcxx/utilities/optional/optional.object/optional.object.observe/assert.op_arrow.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <optional>
 
 // constexpr T* optional<T>::operator->();
 // constexpr const T* optional<T>::operator->() const;
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <optional>
 
 #include "check_assertion.h"
 
 struct X {
     int test() const { return 3; }
 };

libcxx/test/std/algorithms/alg.sorting/alg.heap.operations/pop.heap/assert.pop_heap.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <algorithm>
 
 // Calling `pop_heap` on an empty range is invalid.
 
 #include <algorithm>
 
 #include <array>

libcxx/test/std/algorithms/alg.sorting/alg.heap.operations/pop.heap/assert.ranges_pop_heap.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <algorithm>
 
 // Calling `ranges::pop_heap` on an empty range is invalid.
 
 #include <algorithm>
 
 #include <array>

libcxx/test/std/algorithms/alg.sorting/alg.clamp/assert.ranges_clamp.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <algorithm>
 
 // In a call to `ranges::clamp(val, low, high)`, `low` must be `<= high`.
 
 #include <algorithm>
 #include <functional>
 

libcxx/test/std/containers/views/mdspan/extents/assert.conversion.pass.cpp

 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 // template<class OtherIndexType, size_t... OtherExtents>
 //     constexpr explicit(see below) extents(const extents<OtherIndexType, OtherExtents...>&) noexcept;
 //
 // Constraints:
 //   * sizeof...(OtherExtents) == rank() is true.

libcxx/test/std/containers/views/mdspan/extents/assert.ctor_from_array.pass.cpp

 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 // Test construction from array:
 //
 // template<class OtherIndexType, size_t N>
 //     constexpr explicit(N != rank_dynamic()) extents(const array<OtherIndexType, N>& exts) noexcept;
 //

libcxx/test/std/containers/views/mdspan/extents/assert.ctor_from_integral.pass.cpp

 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 // Test construction from integral:
 //
 // template<class ... OtherIndexTypes>
 //     constexpr explicit extents(OtherIndexTypes ... exts) noexcept;
 //

libcxx/test/std/containers/views/mdspan/extents/assert.ctor_from_span.pass.cpp

 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // Test construction from span:
 //
 // template<class OtherIndexType, size_t N>
 //     constexpr explicit(N != rank_dynamic()) extents(span<OtherIndexType, N> exts) noexcept;
 //
 // Constraints:
 //   * is_convertible_v<const OtherIndexType&, index_type> is true,

libcxx/test/std/containers/views/mdspan/extents/assert.obs.pass.cpp

 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 // static constexpr size_t static_extent(rank_type i) noexcept;
 //
 //   Preconditions: i < rank() is true.
 //
 //   Returns: Ei.

libcxx/test/std/containers/views/mdspan/layout_left/assert.conversion.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 // template<class OtherExtents>
 //   constexpr explicit(!is_convertible_v<OtherExtents, extents_type>)
 //     mapping(const mapping<OtherExtents>&) noexcept;
 
 // Constraints: is_constructible_v<extents_type, OtherExtents> is true.

libcxx/test/std/containers/views/mdspan/layout_left/assert.ctor.extents.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 
 // constexpr mapping(const extents_type& e) noexcept;
 //
 // Preconditions: The size of the multidimensional index space e is representable as a value of type index_type ([basic.fundamental]).
 //

libcxx/test/std/containers/views/mdspan/layout_left/assert.ctor.layout_right.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 // template<class OtherExtents>
 //   constexpr explicit(!is_convertible_v<OtherExtents, extents_type>)
 //     mapping(const layout_right::mapping<OtherExtents>&) noexcept;
 
 // Constraints:

libcxx/test/std/containers/views/mdspan/layout_left/assert.index_operator.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 // template<class... Indices>
 //   constexpr index_type operator()(Indices... i) const noexcept;
 //
 // Constraints:
 //   - sizeof...(Indices) == extents_type::rank() is true,

libcxx/test/std/containers/views/mdspan/layout_left/assert.stride.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 // layout_left::mapping
 //
 // constexpr index_type stride(rank_type i) const noexcept;
 //
 //   Constraints: extents_type::rank() > 0 is true.

libcxx/test/std/containers/views/mdspan/layout_right/assert.conversion.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 // template<class OtherExtents>
 //   constexpr explicit(!is_convertible_v<OtherExtents, extents_type>)
 //     mapping(const mapping<OtherExtents>&) noexcept;
 
 // Constraints: is_constructible_v<extents_type, OtherExtents> is true.

libcxx/test/std/containers/views/mdspan/layout_right/assert.ctor.extents.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 // constexpr mapping(const extents_type& e) noexcept;
 //
 // Preconditions: The size of the multidimensional index space e is representable as a value of type index_type ([basic.fundamental]).
 //
 // Effects: Direct-non-list-initializes extents_ with e.

libcxx/test/std/containers/views/mdspan/layout_right/assert.ctor.layout_left.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 // template<class OtherExtents>
 //   constexpr explicit(!is_convertible_v<OtherExtents, extents_type>)
 //     mapping(const layout_left::mapping<OtherExtents>&) noexcept;
 
 // Constraints:

libcxx/test/std/containers/views/mdspan/layout_right/assert.index_operator.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 // template<class... Indices>
 //   constexpr index_type operator()(Indices... i) const noexcept;
 //
 // Constraints:
 //   - sizeof...(Indices) == extents_type::rank() is true,

libcxx/test/std/containers/views/mdspan/layout_right/assert.stride.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // <mdspan>
 
 // layout_right::mapping
 //
 // constexpr index_type stride(rank_type i) const noexcept;
 //
 //   Constraints: extents_type::rank() > 0 is true.

libcxx/test/std/utilities/utility/utility.unreachable/assert.unreachable.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
-
 // REQUIRES: has-unix-headers
+// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 // Make sure that reaching std::unreachable() with assertions enabled triggers an assertion.
 
 #include <utility>
 
 #include "check_assertion.h"
 
 int main(int, char**) {
     TEST_LIBCPP_ASSERT_FAILURE(std::unreachable(), "std::unreachable() was reached");
 
     return 0;
 }

libcxx/test/support/test.support/test_check_assertion.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // REQUIRES: has-unix-headers
-// UNSUPPORTED: c++03
+// UNSUPPORTED: c++03, !libcpp-has-hardened-mode && !libcpp-has-debug-mode
 // XFAIL: availability-verbose_abort-missing
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_ASSERTIONS=1
 
 #include <cassert>
 #include <cstdio>
 #include <string>
 
 #include "check_assertion.h"
 
 template <class Func>

libcxx/utils/ci/buildkite-pipeline.yml

agents:
       queue: "libcxx-builders"
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
-  - label: "Assertions enabled"
-    command: "libcxx/utils/ci/run-buildbot generic-assertions"
-    artifact_paths:
-      - "**/test-results.xml"
-      - "**/*.abilist"
-    env:
-        CC: "clang-${LLVM_HEAD_VERSION}"
-        CXX: "clang++-${LLVM_HEAD_VERSION}"
-        ENABLE_CLANG_TIDY: "On"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
   - label: "Hardened mode"
     command: "libcxx/utils/ci/run-buildbot generic-hardened-mode"
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
- label: "Apple back-deployment macosx11.0 arm64"
         os: "macos"
         arch: "arm64"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
-    - label: "Apple back-deployment with assertions enabled"
-      command: "libcxx/utils/ci/run-buildbot apple-system-backdeployment-assertions-11.0"
+    - label: "Apple back-deployment with hardening enabled"
+      command: "libcxx/utils/ci/run-buildbot apple-system-backdeployment-hardened-11.0"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       agents:
         queue: "libcxx-builders"
         os: "macos"
       retry:
         automatic:

libcxx/utils/ci/run-buildbot

 generic-merged)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-merged.cmake" \
                    -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBCXXABI_TEST_CONFIG="llvm-libc++abi-merged.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-merged.cfg.in"
     check-runtimes
 ;;
-generic-assertions)
-    clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-assertions.cmake"
-    check-runtimes
-    check-abi-list
-;;
 generic-hardened-mode)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-hardened-mode.cmake"
     check-runtimes
     check-abi-list
 ;;
 generic-debug-mode)
     clean
xcrun --sdk macosx                                              \
             --install-dir ${INSTALL_DIR}                            \
             --symbols-dir "${BUILD_DIR}/symbols"                    \
             --architectures "${arch}"                               \
             --version "999.99"
 
     # TODO: It would be better to run the tests against the fake-installed version of libc++ instead
     xcrun --sdk macosx ninja -vC "${BUILD_DIR}/${arch}" check-cxx check-cxxabi check-cxx-abilist
 ;;
-apple-system-backdeployment-assertions-*)
+apple-system-backdeployment-hardened-*)
     clean
 
     if [[ "${OSX_ROOTS}" == "" ]]; then
         echo "--- Downloading previous macOS dylibs"
         PREVIOUS_DYLIBS_URL="https://dl.dropboxusercontent.com/s/gmcfxwgl9f9n6pu/libcxx-roots.tar.gz"
         OSX_ROOTS="${BUILD_DIR}/macos-roots"
         mkdir -p "${OSX_ROOTS}"
         curl "${PREVIOUS_DYLIBS_URL}" | tar -xz --strip-components=1 -C "${OSX_ROOTS}"
     fi
 
-    DEPLOYMENT_TARGET="${BUILDER#apple-system-backdeployment-assertions-}"
+    DEPLOYMENT_TARGET="${BUILDER#apple-system-backdeployment-hardened-}"
 
     # TODO: On Apple platforms, we never produce libc++abi.1.dylib or libunwind.1.dylib,
     #       only libc++abi.dylib and libunwind.dylib. Fix that in the build so that the
     #       tests stop searching for @rpath/libc++abi.1.dylib and @rpath/libunwind.1.dylib.
     cp "${OSX_ROOTS}/macOS/libc++abi/${DEPLOYMENT_TARGET}/libc++abi.dylib" \
        "${OSX_ROOTS}/macOS/libc++abi/${DEPLOYMENT_TARGET}/libc++abi.1.dylib"
     cp "${OSX_ROOTS}/macOS/libunwind/${DEPLOYMENT_TARGET}/libunwind.dylib" \
        "${OSX_ROOTS}/macOS/libunwind/${DEPLOYMENT_TARGET}/libunwind.1.dylib"
 
     arch="$(uname -m)"
     PARAMS="target_triple=${arch}-apple-macosx${DEPLOYMENT_TARGET}"
     PARAMS+=";cxx_runtime_root=${OSX_ROOTS}/macOS/libc++/${DEPLOYMENT_TARGET}"
     PARAMS+=";abi_runtime_root=${OSX_ROOTS}/macOS/libc++abi/${DEPLOYMENT_TARGET}"
     PARAMS+=";unwind_runtime_root=${OSX_ROOTS}/macOS/libunwind/${DEPLOYMENT_TARGET}"
-    PARAMS+=";enable_assertions=True"
+    PARAMS+=";hardening_mode=hardened"
 
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Apple.cmake" \
                    -DLIBCXX_TEST_CONFIG="apple-libc++-backdeployment.cfg.in" \
                    -DLIBCXXABI_TEST_CONFIG="apple-libc++abi-backdeployment.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="apple-libunwind-backdeployment.cfg.in" \
                    -DLIBCXX_TEST_PARAMS="${PARAMS}" \
                    -DLIBCXXABI_TEST_PARAMS="${PARAMS}" \
                    -DLIBUNWIND_TEST_PARAMS="${PARAMS}"

libcxx/utils/libcxx/test/params.py

Parameter(
         ]
         if experimental
         else [
             AddFeature("libcpp-has-no-incomplete-pstl"),
             AddFeature("libcpp-has-no-experimental-stop_token"),
         ],
     ),
     Parameter(
         name="long_tests",
         choices=[True, False],
         type=bool,
         default=True,
         help="Whether to enable tests that take longer to run. This can be useful when running on a very slow device.",
         actions=lambda enabled: [] if not enabled else [AddFeature("long_tests")],
     ),
     Parameter(
-        name="enable_assertions",
-        choices=[True, False],
-        type=bool,
-        default=False,
-        help="Whether to enable assertions when compiling the test suite. This is only meaningful when "
-        "running the tests against libc++.",
-        actions=lambda assertions: [] if not assertions else [
-            AddCompileFlag("-D_LIBCPP_ENABLE_ASSERTIONS=1"),
-            AddFeature("libcpp-has-assertions"),
-        ],
-    ),
-    Parameter(
         name="hardening_mode",
         choices=["unchecked", "hardened", "debug"],
         type=str,
         default="unchecked",
         help="Whether to enable the hardened mode or the debug mode when compiling the test suite. This is only "
         "meaningful when running the tests against libc++.",
         actions=lambda hardening_mode: filter(
             None,