It was previously reverted by 8406839d19.
---
This flag was introduced by
6818991d71
commit 6818991d71
Author: Ted Kremenek <kremenek@apple.com>
Date: Mon Dec 7 22:06:12 2009 +0000
Add clang-cc option '-analyzer-opt-analyze-nested-blocks' to treat
block literals as an entry point for analyzer checks.
The last reference was removed by this commit:
5c32dfc5fb
commit 5c32dfc5fb
Author: Anna Zaks <ganna@apple.com>
Date: Fri Dec 21 01:19:15 2012 +0000
[analyzer] Add blocks and ObjC messages to the call graph.
This paves the road for constructing a better function dependency graph.
If we analyze a function before the functions it calls and inlines,
there is more opportunity for optimization.
Note, we add call edges to the called methods that correspond to
function definitions (declarations with bodies).
Consequently, we should remove this dead flag.
However, this arises a couple of burning questions.
- Should the `cc1` frontend still accept this flag - to keep
tools/users passing this flag directly to `cc1` (which is unsupported,
unadvertised) working.
- If we should remain backward compatible, how long?
- How can we get rid of deprecated and obsolete flags at some point?
Reviewed By: martong
Differential Revision: https://reviews.llvm.org/D126067
When I read the code I found it easier to reason about if `getUserMode`
is inlined. It might be a personal preference though.
Reviewed By: martong
Differential Revision: https://reviews.llvm.org/D127486
I'm trying to remove unused options from the `Analyses.def` file, then
merge the rest of the useful options into the `AnalyzerOptions.def`.
Then make sure one can set these by an `-analyzer-config XXX=YYY` style
flag.
Then surface the `-analyzer-config` to the `clang` frontend;
After all of this, we can pursue the tablegen approach described
https://discourse.llvm.org/t/rfc-tablegen-clang-static-analyzer-engine-options-for-better-documentation/61488
In this patch, I'm proposing flag deprecations.
We should support deprecated analyzer flags for exactly one release. In
this case I'm planning to drop this flag in `clang-16`.
In the clang frontend, now we won't pass this option to the cc1
frontend, rather emit a warning diagnostic reminding the users about
this deprecated flag, which will be turned into error in clang-16.
Unfortunately, I had to remove all the tests referring to this flag,
causing a mass change. I've also added a test for checking this warning.
I've seen that `scan-build` also uses this flag, but I think we should
remove that part only after we turn this into a hard error.
Reviewed By: martong
Differential Revision: https://reviews.llvm.org/D126215
This patch introduces the new -fdriver-only flag which instructs Clang to only execute the driver logic without running individual jobs. In a way, this is very similar to -###, with the following differences:
* it doesn't automatically print all jobs,
* it doesn't avoid side effects (e.g. it will generate compilation database when -MJ is specified).
This flag will be useful in testing D121997.
Reviewed By: dexonsmith, egorzhdan
Differential Revision: https://reviews.llvm.org/D127408
This flag was introduced by
6818991d71
commit 6818991d71
Author: Ted Kremenek <kremenek@apple.com>
Date: Mon Dec 7 22:06:12 2009 +0000
Add clang-cc option '-analyzer-opt-analyze-nested-blocks' to treat
block literals as an entry point for analyzer checks.
The last reference was removed by this commit:
5c32dfc5fb
commit 5c32dfc5fb
Author: Anna Zaks <ganna@apple.com>
Date: Fri Dec 21 01:19:15 2012 +0000
[analyzer] Add blocks and ObjC messages to the call graph.
This paves the road for constructing a better function dependency graph.
If we analyze a function before the functions it calls and inlines,
there is more opportunity for optimization.
Note, we add call edges to the called methods that correspond to
function definitions (declarations with bodies).
Consequently, we should remove this dead flag.
However, this arises a couple of burning questions.
- Should the `cc1` frontend still accept this flag - to keep
tools/users passing this flag directly to `cc1` (which is unsupported,
unadvertised) working.
- If we should remain backward compatible, how long?
- How can we get rid of deprecated and obsolete flags at some point?
Reviewed By: martong
Differential Revision: https://reviews.llvm.org/D126067
I'm trying to remove unused options from the `Analyses.def` file, then
merge the rest of the useful options into the `AnalyzerOptions.def`.
Then make sure one can set these by an `-analyzer-config XXX=YYY` style
flag.
Then surface the `-analyzer-config` to the `clang` frontend;
After all of this, we can pursue the tablegen approach described
https://discourse.llvm.org/t/rfc-tablegen-clang-static-analyzer-engine-options-for-better-documentation/61488
In this patch, I'm proposing flag deprecations.
We should support deprecated analyzer flags for exactly one release. In
this case I'm planning to drop this flag in `clang-16`.
In the clang frontend, now we won't pass this option to the cc1
frontend, rather emit a warning diagnostic reminding the users about
this deprecated flag, which will be turned into error in clang-16.
Unfortunately, I had to remove all the tests referring to this flag,
causing a mass change. I've also added a test for checking this warning.
I've seen that `scan-build` also uses this flag, but I think we should
remove that part only after we turn this into a hard error.
Reviewed By: martong
Differential Revision: https://reviews.llvm.org/D126215
The `Builder.defineMacro("__cpp_multidimensional_subscript", "202110L");` line has
some `U+C2AD`s that shouldn't necessary here. So removed them.
Differential Revision: https://reviews.llvm.org/D127066
Vector types in hlsl is using clang ext_vector_type.
Declaration of vector types is in builtin header hlsl.h.
hlsl.h will be included by default for hlsl shader.
Reviewed By: Anastasia
Differential Revision: https://reviews.llvm.org/D125052
Vector types in hlsl is using clang ext_vector_type.
Declaration of vector types is in builtin header hlsl.h.
hlsl.h will be included by default for hlsl shader.
Reviewed By: Anastasia
Differential Revision: https://reviews.llvm.org/D125052
This reverts commit 3988bd1398.
Did not build on this bot:
https://lab.llvm.org/buildbot#builders/215/builds/6372
/usr/include/c++/9/bits/predefined_ops.h:177:11: error: no match for call to
‘(llvm::less_first) (std::pair<long unsigned int, llvm::bolt::BinaryBasicBlock*>&, const std::pair<long unsigned int, std::nullptr_t>&)’
177 | { return bool(_M_comp(*__it, __val)); }
One could reuse this functor instead of rolling out your own version.
There were a couple other cases where the code was similar, but not
quite the same, such as it might have an assertion in the lambda or other
constructs. Thus, I've not touched any of those, as it might change the
behavior in some way.
As per https://discourse.llvm.org/t/submitting-simple-nfc-patches/62640/3?u=steakhal
Chris Lattner
> LLVM intentionally has a “yes, you can apply common sense judgement to
> things” policy when it comes to code review. If you are doing mechanical
> patches (e.g. adopting less_first) that apply to the entire monorepo,
> then you don’t need everyone in the monorepo to sign off on it. Having
> some +1 validation from someone is useful, but you don’t need everyone
> whose code you touch to weigh in.
Differential Revision: https://reviews.llvm.org/D126068
This is a commit with the following changes:
* Remove `ExcludedPreprocessorDirectiveSkipMapping` and related functionality
Removes `ExcludedPreprocessorDirectiveSkipMapping`; its intended benefit for fast skipping of excluded directived blocks
will be superseded by a follow-up patch in the series that will use dependency scanning lexing for the same purpose.
* Refactor dependency scanning to produce pre-lexed preprocessor directive tokens, instead of minimized sources
Replaces the "source minimization" mechanism with a mechanism that produces lexed dependency directives tokens.
* Make the special lexing for dependency scanning a first-class feature of the `Preprocessor` and `Lexer`
This is bringing the following benefits:
* Full access to the preprocessor state during dependency scanning. E.g. a component can see what includes were taken and where they were located in the actual sources.
* Improved performance for dependency scanning. Measurements with a release+thin-LTO build shows ~ -11% reduction in wall time.
* Opportunity to use dependency scanning lexing to speed-up skipping of excluded conditional blocks during normal preprocessing (as follow-up, not part of this patch).
For normal preprocessing measurements show differences are below the noise level.
Since, after this change, we don't minimize sources and pass them in place of the real sources, `DependencyScanningFilesystem` is not technically necessary, but it has valuable performance benefits for caching file `stat`s along with the results of scanning the sources. So the setup of using the `DependencyScanningFilesystem` during a dependency scan remains.
Differential Revision: https://reviews.llvm.org/D125486
Differential Revision: https://reviews.llvm.org/D125487
Differential Revision: https://reviews.llvm.org/D125488
This is first of a series of patches for making the special lexing for dependency scanning a first-class feature of the `Preprocessor` and `Lexer`.
This patch only includes NFC renaming changes to make reviewing of the functionality changing parts easier.
Differential Revision: https://reviews.llvm.org/D125484
Since this didn't make it into the v14 release - anyone requesting the
v14 ABI shouldn't get this GCC-compatible change that isn't backwards
compatible with v14 Clang.
Differential Revision: https://reviews.llvm.org/D126334
When Clang generates the path prefix (i.e. the path of the directory
where the file is) when generating FILE, __builtin_FILE(), and
std::source_location, Clang uses the platform-specific path separator
character of the build environment where Clang _itself_ is built. This
leads to inconsistencies in Chrome builds where Clang running on
non-Windows environments uses the forward slash (/) path separator
while Clang running on Windows builds uses the backslash (\) path
separator. To fix this, we add a flag -ffile-reproducible (and its
inverse, -fno-file-reproducible) to have Clang use the target's
platform-specific file separator character.
Additionally, the existing flags -fmacro-prefix-map and
-ffile-prefix-map now both imply -ffile-reproducible. This can be
overriden by setting -fno-file-reproducible.
[0]: https://crbug.com/1310767
Differential revision: https://reviews.llvm.org/D122766
D87451 added -mignore-xcoff-visibility for AIX targets and made it the default (which mimicked the behaviour of the XL 16.1 compiler on AIX).
However, ignoring hidden visibility has unwanted side effects and some libraries depend on visibility to hide non-ABI facing entities from user headers and
reserve the right to change these implementation details based on this (https://libcxx.llvm.org/DesignDocs/VisibilityMacros.html). This forces us to use
internal linkage fallbacks for these cases on AIX and creates an unwanted divergence in implementations on the plaform.
For these reasons, it's preferable to not add -mignore-xcoff-visibility by default, which is what this patch does.
Reviewed By: DiggerLin
Differential Revision: https://reviews.llvm.org/D125141
This is generally a better default for tools other than the compiler, which
shouldn't assume a PCH file on disk is something they can consume.
Preserve the old behavior in places associated with libclang/c-index-test
(including ASTUnit) as there are tests relying on it and most important
consumers are out-of-tree. It's unclear whether the tests are specifically
trying to test this functionality, and what the downstream implications of
removing it are. Hopefully someone more familiar can clean this up in future.
Differential Revision: https://reviews.llvm.org/D125149
We know we're going to overwrite it anyway.
It'd be a bit of work to coordinate not generating it at all, but setting this
flag avoids generating ~10k of the 13k string.
Differential Revision: https://reviews.llvm.org/D125180
Compared to the old implementation:
* In C++, we only recurse into aggregate classes.
* Unnamed bit-fields are not printed.
* Constant evaluation is supported.
* Proper conversion is done when passing arguments through `...`.
* Additional arguments are supported and are injected prior to the
format string; this directly supports use with `fprintf`, for example.
* An arbitrary callable can be passed rather than only a function
pointer. In particular, in C++, a function template or overload set is
acceptable.
* All text generated by Clang is printed via `%s` rather than directly;
this avoids issues where Clang's pretty-printing output might itself
contain a `%` character.
* Fields of types that we don't know how to print are printed with a
`"*%p"` format and passed by address to the print function.
* No return value is produced.
Reviewed By: aaron.ballman, erichkeane, yihanaa
Differential Revision: https://reviews.llvm.org/D124221
If clang is passed "-include foo.h", it will rewrite to "-include-pch foo.h.pch"
before passing it to cc1, if foo.h.pch exists.
Existence is checked, but validity is not. This is probably a reasonable
assumption for the compiler itself, but not for clang-based tools where the
actual compiler may be a different version of clang, or even GCC.
In the end, we lose our -include, we gain a -include-pch that can't be used,
and the file often fails to parse.
I would like to turn this off for all non-clang invocations (i.e.
createInvocationFromCommandLine), but we have explicit tests of this behavior
for libclang and I can't work out the implications of changing it.
Instead this patch:
- makes it optional in the driver, default on (no change)
- makes it optional in createInvocationFromCommandLine, default on (no change)
- changes driver to do IO through the VFS so it can be tested
- tests the option
- turns the option off in clangd where the problem was reported
Subsequent patches should make libclang opt in explicitly and flip the default
for all other tools. It's probably also time to extract an options struct
for createInvocationFromCommandLine.
Fixes https://github.com/clangd/clangd/issues/856
Fixes https://github.com/clangd/vscode-clangd/issues/324
Differential Revision: https://reviews.llvm.org/D124970
It's accumulating way too many optional params (see D124970)
While here, improve the name and the documentation.
Differential Revision: https://reviews.llvm.org/D124971
The Itanium C++ ABI says prefixes are substitutable. For most prefixes
we already handle this: the manglePrefix(const DeclContext *, bool) and
manglePrefix(QualType) overloads explicitly handles substitutions or
defer to functions that handle substitutions on their behalf. The
manglePrefix(NestedNameSpecifier *) overload, however, is different and
handles some cases implicitly, but not all. The Identifier case was not
handled; this change adds handling for it, as well as a test case.
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D122663
When the denormal-fp-math option is used, this should set the
denormal handling mode for all floating point types. However,
currently 32-bit float types can ignore this setting as there is a
variant of the option, denormal-fp-math-f32, specifically for that type
which takes priority when checking the mode based on type and remains
at the default of IEEE. From the description, denormal-fp-math would
be expected to set the mode for floats unless overridden by the f32
variant, and code in the front end only emits the f32 option if it is
different to the general one, so setting just denormal-fp-math should
be valid.
This patch changes the denormal-fp-math option to also set the f32
mode. If denormal-fp-math-f32 is also specified, this is then
overridden as expected, but if it is absent floats will be set to the
mode specified by the former option, rather than remain on the default.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D122589
When assertions are enabled, clang will perform RoundTrip for CompilerInvocation argument generation. ibt-seal flags are currently missing in this argument generation, and because of that, the feature doesn't get enabled for these cases. Performing RoundTrip is the default for assert builds, rendering the feature broken in these scenarios.
This patch fixes this and adds a test to properly verify that modules are being generated with the flag when -mibt-seal is used.
Please, add any known relevant reviewer which I may have missed.
[1] - https://reviews.llvm.org/D116070
Reviewed By: pengfei, gftg, aaron.ballman, nickdesaulniers
Differential Revision: https://reviews.llvm.org/D118052
Delete the output streams coming from
CompilerInstance::createOutputFile() and friends once writes are
finished. Concretely, replacing `OS->flush()` with `OS.reset()` in:
- `ExtractAPIAction::EndSourceFileAction()`
- `PrecompiledPreambleAction::setEmittedPreamblePCH()`
- `cc1_main()'s support for `-ftime-trace`
This fixes theoretical bugs related to proxy streams, which may have
cleanups to run in their destructor. For example, a proxy that
CompilerInstance sometimes uses is `buffer_ostream`, which wraps a
`raw_ostream` lacking pwrite support and adds it. `flush()` does not
promise that output is complete; `buffer_ostream` needs to wait until
the destructor to forward anything so that it can service later calls to
`pwrite()`. If the destructor isn't called then the proxied stream
hasn't received any content.
This also protects against some logic bugs, triggering a null
dereference on a later attempt to write to the stream.
No tests, since in practice these particular code paths never use
use `buffer_ostream`; you need to be writing a binary file to a
pipe (such as stdout) to hit it, but `-extract-api` writes a text file
and the other two use computed filenames that will never (in practice)
be a pipe. This is effectively NFC, for now.
But I have some other patches in the works that add guard rails,
crashing if the stream hasn't been destructed by the time the
CompilerInstance is told to keep the output file, since in most cases
this is a problem.
Differential Revision: https://reviews.llvm.org/D124635
After building a PCH, the vector capacity is on average ~1/3 unused.
If we're going to keep it in memory for a while, reallocate to the right size.
Take care to do this once clang is destroyed so that we can reuse its
memory rather than requesting more.
Differential Revision: https://reviews.llvm.org/D124242
> Includes regression test for problem noted by @hans.
> is reverts commit 973de71.
>
> Differential Revision: https://reviews.llvm.org/D106898
Feature implemented as-is is fairly expensive and hasn't been used by
libc++. A potential reimplementation is possible if libc++ become
interested in this feature again.
Differential Revision: https://reviews.llvm.org/D123885
This adds file types and handling for three input types, representing a C++20
header unit source:
1. When provided with a complete pathname for the header.
2. For a header to be looked up (by the frontend) in the user search paths
3. For a header to be looked up in the system search paths.
We also add a pre-processed file type (although that is a single type, regardless
of the original input type).
These types may be specified with -xc++-{user,system,header-unit}-header xxxx.
These types allow us to disambiguate header unit jobs from PCH ones, and thus
we handle these differently from other header jobs in two ways:
1. The job construction is altered to build a C++20 header unit (rather than a
PCH file, as would be the case for other headers).
2. When the type is "user" or "system" we defer checking for the file until the
front end is run, since we need to look up the header in the relevant paths
which are not known at this point.
Differential Revision: https://reviews.llvm.org/D121588
This reverts commit eadf352707.
The reland fixes a couple of places in clang that were unneccesarily
requesting a null-terminated buffer of the PCH, and hitting assertions.
Instead of unconditionally copying the PCHBuffer into an ostream which can be
backed either by a string or a file, just make the PCHBuffer itself the
in-memory storage.
Differential Revision: https://reviews.llvm.org/D124180
- Remove fiddly union, preambles are heavyweight
- Remove fiddly move constructors in TempPCHFile and PCHStorage, use unique_ptr
- Remove unneccesary accessors on PCHStorage
- Remove trivial InMemoryStorage
- Move implementation details into cpp file
This is a prefactoring, followup change will change the in-memory PCHStorage to
avoid extra string copies while creating it.
Differential Revision: https://reviews.llvm.org/D124177
This patch removes use of the deprecated `DirectoryEntry::getName()` from `FrontendAction::BeginSourceFile()`.
Reviewed By: bnbarham
Differential Revision: https://reviews.llvm.org/D123853
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.
New checks rely on 2 invariants:
1) For frontend instrumentation, MD_prof branch_weights will always be
populated before llvm.expect intrinsics are lowered.
2) for IR and sample profiling, llvm.expect intrinsics will always be
lowered before branch_weights are populated from the IR profiles.
These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.
Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D115907
This patch removes use of the deprecated `DirectoryEntry::getName()` from `collectIncludePCH` by using `{File,Directory}EntryRef` instead.
Reviewed By: bnbarham
Differential Revision: https://reviews.llvm.org/D123769
This patch changes type of the `File` parameter in `PPCallbacks::InclusionDirective()` from `const FileEntry *` to `Optional<FileEntryRef>`.
With the API change in place, this patch then removes some uses of the deprecated `FileEntry::getName()` (e.g. in `DependencyGraph.cpp` and `ModuleDependencyCollector.cpp`).
Reviewed By: dexonsmith, bnbarham
Differential Revision: https://reviews.llvm.org/D123574
This removes the -flegacy-pass-manager and
-fno-experimental-new-pass-manager options, and the corresponding
support code in BackendUtil. The -fno-legacy-pass-manager and
-fexperimental-new-pass-manager options are retained as no-ops.
Differential Revision: https://reviews.llvm.org/D123609
The function is moved from clangFrontend to clangBasic, which allows tools
(e.g. clang pseudoparser) which don't depend on clangFrontend to use.
Differential Revision: https://reviews.llvm.org/D121375
The Randstruct feature is a compile-time hardening technique that
randomizes the field layout for designated structures of a code base.
Admittedly, this is mostly useful for closed-source releases of code,
since the randomization seed would need to be available for public and
open source applications.
Why implement it? This patch set enhances Clang’s feature parity with
that of GCC which already has the Randstruct feature. It's used by the
Linux kernel in certain structures to help thwart attacks that depend on
structure layouts in memory.
This patch set is a from-scratch reimplementation of the Randstruct
feature that was originally ported to GCC. The patches for the GCC
implementation can be found here:
https://www.openwall.com/lists/kernel-hardening/2017/04/06/14
Link: https://lists.llvm.org/pipermail/cfe-dev/2019-March/061607.html
Co-authored-by: Cole Nixon <nixontcole@gmail.com>
Co-authored-by: Connor Kuehl <cipkuehl@gmail.com>
Co-authored-by: James Foster <jafosterja@gmail.com>
Co-authored-by: Jeff Takahashi <jeffrey.takahashi@gmail.com>
Co-authored-by: Jordan Cantrell <jordan.cantrell@mail.com>
Co-authored-by: Nikk Forbus <nicholas.forbus@gmail.com>
Co-authored-by: Tim Pugh <nwtpugh@gmail.com>
Co-authored-by: Bill Wendling <isanbard@gmail.com>
Signed-off-by: Bill Wendling <isanbard@gmail.com>
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D121556
This reverts commit 3f0587d0c6.
Not all tests pass after a few rounds of fixes.
I spot one failure that std::shuffle (potentially different results with
different STL implementations) was misused and replaced it with llvm::shuffle,
but there appears to be another failure in a Windows build.
The latest failure is reported on https://reviews.llvm.org/D121556#3440383
The Randstruct feature is a compile-time hardening technique that
randomizes the field layout for designated structures of a code base.
Admittedly, this is mostly useful for closed-source releases of code,
since the randomization seed would need to be available for public and
open source applications.
Why implement it? This patch set enhances Clang’s feature parity with
that of GCC which already has the Randstruct feature. It's used by the
Linux kernel in certain structures to help thwart attacks that depend on
structure layouts in memory.
This patch set is a from-scratch reimplementation of the Randstruct
feature that was originally ported to GCC. The patches for the GCC
implementation can be found here:
https://www.openwall.com/lists/kernel-hardening/2017/04/06/14
Link: https://lists.llvm.org/pipermail/cfe-dev/2019-March/061607.html
Co-authored-by: Cole Nixon <nixontcole@gmail.com>
Co-authored-by: Connor Kuehl <cipkuehl@gmail.com>
Co-authored-by: James Foster <jafosterja@gmail.com>
Co-authored-by: Jeff Takahashi <jeffrey.takahashi@gmail.com>
Co-authored-by: Jordan Cantrell <jordan.cantrell@mail.com>
Co-authored-by: Nikk Forbus <nicholas.forbus@gmail.com>
Co-authored-by: Tim Pugh <nwtpugh@gmail.com>
Co-authored-by: Bill Wendling <isanbard@gmail.com>
Signed-off-by: Bill Wendling <isanbard@gmail.com>
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D121556
The LANGOPT macro allows you to specify a default value for the
langauge option. However, it's expected that these values be constant
rather than depending on other language options (because the
constructor setting the default values does not know the language mode
at the time it's being constructed).
Some of our language options were abusing this and passing in other
language mode options which were then set correctly by other parts of
frontend initialization. This removes the default values for the
language options, and then ensures they're consistently set from the
same place when setting language standard defaults.
- isValid: FileManager only ever returns valid FileEntries (see next point)
- construction from outside FileManager (both FileEntry and DirectoryEntry).
It's not possible to create a useful FileEntry this way, there are no setters.
This was only used in FileEntryTest, added a friend to enable this.
A real constructor is cleaner but requires larger changes to FileManager.
Differential Revision: https://reviews.llvm.org/D123197
compiler is allowed to use optimizations that allow reassociation and
transformations that don’t guaranty accuracy.
For example (x+y)+z is transformed into x+(y+z) . Although
mathematically equivalent, these two expressions may not lead to the
same final result due to errors of summation.
Or x/x is transformed into 1.0 but x could be 0.0, INF or NaN. And so
this transformation also may not lead to the same final result.
Setting the eval method 'ffp-eval-method' or via '#pragma clang fp
eval_method' in this mode, doesn’t have any effect.
This patch adds code to warn the user of this.
Differential Revision: https://reviews.llvm.org/D122155
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.
New checks rely on 2 invariants:
1) For frontend instrumentation, MD_prof branch_weights will always be
populated before llvm.expect intrinsics are lowered.
2) for IR and sample profiling, llvm.expect intrinsics will always be
lowered before branch_weights are populated from the IR profiles.
These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.
Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D115907
Fleshing this out now allows me to rely on enum math to translate
values rather than having to translate the off cases.
I should have added this in the first pass, but wasn't thinking about
it.
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.
New checks rely on 2 invariants:
1) For frontend instrumentation, MD_prof branch_weights will always be
populated before llvm.expect intrinsics are lowered.
2) for IR and sample profiling, llvm.expect intrinsics will always be
lowered before branch_weights are populated from the IR profiles.
These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.
Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D115907
Bringing in HLSL as a language as well as language options for each of
the HLSL language standards.
While the HLSL language is unimplemented, this patch adds the
HLSL-specific preprocessor defines which enables testing of the command
line options through the driver.
Reviewed By: pete, rnk
Differential Revision: https://reviews.llvm.org/D122087
When the -fdirectives-only option is used together with -E, the preprocessor
output reflects evaluation of if/then/else directives.
As such, it preserves defines and undefs of macros that are still live after
such processing. The intent is that this output could be consumed as input
to generate considered a C++20 header unit.
We strip out any (unused) defines that come from built-in, built-in-file or
command line; these are re-added when the preprocessed source is consumed.
Differential Revision: https://reviews.llvm.org/D121099
We wish to support emitting a pre-processed output for an importable
header unit, that can be consumed to produce the same header units as
the original source.
This means that ee need to find the original filename used to produce
the re-preprocessed output, so that it can be assigned as the module
name. This is peeked from the first line of the pre-processed source
when the action sets up the files.
Differential Revision: https://reviews.llvm.org/D121098
This is support for the user-facing options to create importable header units
from headers in the user or system search paths (or to be given an absolute path).
This means that an incomplete header path will be passed by the driver and the
lookup carried out using the search paths present when the front end is run.
To support this, we introduce file fypes for c++-{user,system,header-unit}-header.
These terms are the same as the ones used by GCC, to minimise the differences for
tooling (and users).
The preprocessor checks for headers before issuing a warning for
"#pragma once" in a header build. We ensure that the importable header units
are recognised as headers in order to avoid such warnings.
Differential Revision: https://reviews.llvm.org/D121096
This is the first in a series of patches that introduce C++20 importable
header units.
These differ from clang header modules in that:
(a) they are identifiable by an internal name
(b) they represent the top level source for a single header - although
that might include or import other headers.
We name importable header units with the path by which they are specified
(although that need not be the absolute path for the file).
So "foo/bar.h" would have a name "foo/bar.h". Header units are made a
separate module type so that we can deal with diagnosing places where they
are permitted but a named module is not.
Differential Revision: https://reviews.llvm.org/D121095
Allow goto, labelled statements as well as `static`, `thread_local`, and
non-literal variables in `constexpr` functions.
As specified. for all of the above (except labelled statements) constant
evaluation of the construct still fails.
For `constexpr` bodies, the proposal is implemented with diagnostics as
a language extension in older language modes. For determination of
whether a lambda body satisfies the requirements for a constexpr
function, the proposal is implemented only in C++2b mode to retain the
semantics of older modes for programs conforming to them.
Reviewed By: aaron.ballman, hubert.reinterpretcast, erichkeane
Differential Revision: https://reviews.llvm.org/D111400
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.
New checks rely on 2 invariants:
1) For frontend instrumentation, MD_prof branch_weights will always be
populated before llvm.expect intrinsics are lowered.
2) for IR and sample profiling, llvm.expect intrinsics will always be
lowered before branch_weights are populated from the IR profiles.
These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.
Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.
Differential Revision: https://reviews.llvm.org/D115907
Add facilities for extract-api:
- Structs/classes to hold collected API information: `APIRecord`, `API`
- Structs/classes for API information:
- `AvailabilityInfo`: aggregated availbility information
- `DeclarationFragments`: declaration fragments
- `DeclarationFragmentsBuilder`: helper class to build declaration
fragments for various types/declarations
- `FunctionSignature`: function signature
- Serialization: `Serializer`
- Add output file for `ExtractAPIAction`
- Refactor `clang::RawComment::getFormattedText` to provide an
additional `getFormattedLines` for a more detailed view of comment lines
used for the SymbolGraph format
Add support for global records (global variables and functions)
- Add `GlobalRecord` based on `APIRecord` to store global records'
information
- Implement `VisitVarDecl` and `VisitFunctionDecl` in `ExtractAPIVisitor` to
collect information
- Implement serialization for global records
- Add test case for global records
Differential Revision: https://reviews.llvm.org/D119479
clang has support for lazy headers in module maps - if size and/or
modtime and provided in the cppmap file, headers are only resolved when
an include directive for a file with that size/modtime is encoutered.
Before this change, the lazy resolution was all-or-nothing per module.
That means as soon as even one file in that module potentially matched
an include, all lazy files in that module were resolved. With this
change, only files with matching size/modtime will be resolved.
The goal is to avoid unnecessary stat() calls on non-included files,
which is especially valuable on networked file systems, with higher
latency.
Differential Revision: https://reviews.llvm.org/D120569
Exactly what it says on the tin! We had a nasty crash with the following incovation:
$ clang --analyze -Xclang -analyzer-constraints=z3 test.c
fatal error: error in backend: LLVM was not compiled with Z3 support, rebuild with -DLLVM_ENABLE_Z3_SOLVER=ON
... <stack trace> ...
Differential Revision: https://reviews.llvm.org/D120325
Introduce -fgpu-default-stream={legacy|per-thread} option to
support per-thread default stream for HIP runtime.
When -fgpu-default-stream=per-thread, HIP kernels are
launched through hipLaunchKernel_spt instead of
hipLaunchKernel. Also HIP_API_PER_THREAD_DEFAULT_STREAM=1
is defined by the preprocessor to enable other per-thread stream
API's.
Reviewed by: Artem Belevich
Differential Revision: https://reviews.llvm.org/D120298
This patch enables inferring framework modules in explicit builds in all contexts. Until now, inferring framework modules only worked with `-fimplicit-module-maps` due to this block of code:
```
// HeaderSearch::loadFrameworkModule
case LMM_InvalidModuleMap:
// Try to infer a module map from the framework directory.
if (HSOpts->ImplicitModuleMaps)
ModMap.inferFrameworkModule(Dir, IsSystem, /*Parent=*/nullptr);
break;
```
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D113880
It is useful to be able to visualise the C++20 modules content of a PCM file
both for inspection and for testing. In particular, when adding more module
types to support C++20 Partitions and Header Units, we would like to be able
to confirm that the output PCM has the intended structure.
The existing scheme for dumping data is restricted to the content of the AST
file control block, which does not include structural data beyond imports.
The change here makes use of the AST unit that is set up by BeginSourceFile
to query for the information on the primary and sub-modules. We can then
inspect each of these in turn, accounting for Global, Private, Imported and
Exported modules/fragments and then showing the sub-stucture of the main
module(s).
The disadvantage of this mechanism is that it has no easy method to control
the granularity of the output. Perhaps more detailed inspection would be
better handled by a stand-alone module inspection tool.
Differential Revision: https://reviews.llvm.org/D119823
MSVC currently doesn't support 80 bits long double. But ICC does support
it on Windows. Besides, there're also some users asked for this feature.
We can find the discussions from stackoverflow, msdn etc.
Given Clang has already support `-mlong-double-80`, extending it to
support for Windows seems worthwhile.
Reviewed By: rnk, erichkeane
Differential Revision: https://reviews.llvm.org/D115441
Implement P2128R6 in C++23 mode.
Unlike GCC's implementation, this doesn't try to recover when a user
meant to use a comma expression.
Because the syntax changes meaning in C++23, the patch is *NOT*
implemented as an extension. Instead, declaring an array with not
exactly 1 parameter is an error in older languages modes. There is an
off-by-default extension warning in C++23 mode.
Unlike the standard, we supports default arguments;
Ie, we assume, based on conversations in WG21, that the proposed
resolution to CWG2507 will be accepted.
We allow arrays OpenMP sections and C++23 multidimensional array to
coexist:
[a , b] multi dimensional array
[a : b] open mp section
[a, b: c] // error
The rest of the patch is relatively straight forward: we take care to
support an arbitrary number of arguments everywhere.
This patch completely removes the old OpenMP device runtime. Previously,
the old runtime had the prefix `libomptarget-new-` and the old runtime
was simply called `libomptarget-`. This patch makes the formerly new
runtime the only runtime available. The entire project has been deleted,
and all references to the `libomptarget-new` runtime has been replaced
with `libomptarget-`.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D118934
The lexer can attempt to lex a _Pragma and crash with an out of bounds string access when it's
lexing a _Pragma whose string token is an invalid buffer, e.g. when a module header file from which the macro
expansion for that token was deleted from the file system.
Differential Revision: https://reviews.llvm.org/D116052
This patch extends clang frontend to add metadata that can be used to emit macho files with two build version load commands.
It utilizes "darwin.target_variant.triple" and "darwin.target_variant.SDK Version" metadata names for that.
MachO uses two build version load commands to represent an object file / binary that is targeting both the macOS target,
and the Mac Catalyst target. At runtime, a dynamic library that supports both targets can be loaded from either a native
macOS or a Mac Catalyst app on a macOS system. We want to add support to this to upstream to LLVM to be able to build
compiler-rt for both targets, to finish the complete support for the Mac Catalyst platform, which is right now targetable
by upstream clang, but the compiler-rt bits aren't supported because of the lack of this multiple build version support.
Differential Revision: https://reviews.llvm.org/D115415
Part of the _BitInt feature in C2x
(http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2763.pdf) is a new
macro in limits.h named BITINT_MAXWIDTH that can be used to determine
the maximum width of a bit-precise integer type. This macro must expand
to a value that is at least as large as ULLONG_WIDTH.
This adds an implementation-defined macro named __BITINT_MAXWIDTH__ to
specify that value, which is used by limits.h for the standard macro.
This also limits the maximum bit width to 128 bits because backends do
not currently support all mathematical operations (such as division) on
wider types yet. This maximum is expected to be increased in the future.
This matches GCC: https://godbolt.org/z/sM5q95PGY
I realize this is an API break for clang+clang - so I'm totally open to
discussing how we should deal with that. If Apple wants to keep the
Clang layout indefinitely, if we want to put a flag on this so non-Apple
folks can opt out of this fix/new behavior.
Differential Revision: https://reviews.llvm.org/D117616
This reverts commit ef82063207.
- It conflicts with the existing llvm::size in STLExtras, which will now
never be called.
- Calling it without llvm:: breaks C++17 compat
The Clang frontend sometimes fails on the following assertion when launched with `-serialize-diagnostic-file <x>`:
```
Assertion failed: (BlockScope.empty() && CurAbbrevs.empty() && "Block imbalance"), function ~BitstreamWriter, file BitstreamWriter.h, line 125.
```
This was first noticed when passing an unknown command-line argument to `-cc1`.
It turns out the `DiagnosticConsumer::finish()` function should be called as soon as processing of all source files ends, but there are some code paths where that doesn't happen:
1. when command line parsing fails in `cc1_main()`,
2. when `!Act.PrepareToExecute(*this)` or `!createTarget()` evaluate to `true` in `CompilerInstance::ExecuteAction` and the function returns early.
This patch ensures `finish()` is called in all those code paths.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D118150
Patch originally by oktal3000: https://github.com/mikael-s-persson/templight/pull/40
When a template parameter is unnamed, the name of -templight-dump might return
an empty string. This is fine, they are unnamed after all, but it might be more
user friendly to at least describe what entity is unnamed.
Differential Revision: https://reviews.llvm.org/D115521
This change moves EOL detection out of the clang::InclusionRewriter into
llvm::StringRef so that it can be easily reused elsewhere. It also adds
additional explicit test cases to verify the correct and expected return
results.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D117626
Intel's CET/IBT requires every indirect branch target to be an ENDBR instruction. Because of that, the compiler needs to correctly emit these instruction on function's prologues. Because this is a security feature, it is desirable that only actual indirect-branch-targeted functions are emitted with ENDBRs. While it is possible to identify address-taken functions through LTO, minimizing these ENDBR instructions remains a hard task for user-space binaries because exported functions may end being reachable through PLT entries, that will use an indirect branch for such. Because this cannot be determined during compilation-time, the compiler currently emits ENDBRs to every non-local-linkage function.
Despite the challenge presented for user-space, the kernel landscape is different as no PLTs are used. With the intent of providing the most fit ENDBR emission for the kernel, kernel developers proposed an optimization named "ibt-seal" which replaces the ENDBRs for NOPs directly in the binary. The discussion of this feature can be seen in [1].
This diff brings the enablement of the flag -mibt-seal, which in combination with LTO enforces a different policy for ENDBR placement in when the code-model is set to "kernel". In this scenario, the compiler will only emit ENDBRs to address taken functions, ignoring non-address taken functions that are don't have local linkage.
A comparison between an LTO-compiled kernel binaries without and with the -mibt-seal feature enabled shows that when -mibt-seal was used, the number of ENDBRs in the vmlinux.o binary patched by objtool decreased from 44383 to 33192, and that the number of superfluous ENDBR instructions nopped-out decreased from 11730 to 540.
The 540 missed superfluous ENDBRs need to be investigated further, but hypotheses are: assembly code not being taken care of by the compiler, kernel exported symbols mechanisms creating bogus address taken situations or even these being removed due to other binary optimizations like kernel's static_calls. For now, I assume that the large drop in the number of ENDBR instructions already justifies the feature being merged.
[1] - https://lkml.org/lkml/2021/11/22/591
Reviewed By: xiangzhangllvm
Differential Revision: https://reviews.llvm.org/D116070
The `{HeaderSearch,Preprocessor}::LookupFile()` functions take an out-parameter `const DirectoryLookup *&`. Most callers end up creating a `const DirectoryLookup *` variable that's otherwise unused.
This patch changes the out-parameter from reference to a pointer, making it possible to simply pass `nullptr` to the function without the ceremony.
Reviewed By: ahoppen
Differential Revision: https://reviews.llvm.org/D117312
This patch removes bitrotten/dead uses of `DirectoryLookup` in `InclusionRewriter.cpp`.
Reviewed By: ahoppen
Differential Revision: https://reviews.llvm.org/D117309
This completes the implementation of
WG14 N2412 (http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2412.pdf),
which standardizes C on a twos complement representation for integer
types. The only work that remained there was to define the correct
macros in the standard headers, which this patch does.
In D116750, the `clangFrontend` library was added as a dependency of `LexTests` in order to make `clang::ApplyHeaderSearchOptions()` available. This increased the number of TUs the test depends on.
This patch moves the function into `clangLex` and removes dependency of `LexTests` on `clangFrontend`.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D117024
This causes modern glibc to unset math_errhandling MATH_ERRNO. gcc 12
also sets some other macros, but most of them are associated with
flags ignored by clang, so without library examples, it is difficult to
determine whether they should be set. I think setting this one macro is
OK for now.
Implementation is based on the "expected type" as used for
designated-initializers in braced init lists. This means it can deduce the type
in some cases where it's not written:
void foo(Widget);
foo({ /*help here*/ });
Only basic constructor calls are in scope of this patch, excluded are:
- aggregate initialization (no help is offered for aggregates)
- initializer_list initialization (no help is offered for these constructors)
Fixes https://github.com/clangd/clangd/issues/306
Differential Revision: https://reviews.llvm.org/D116317
This avoids an unnecessary copy required by 'return OS.str()', allowing
instead for NRVO or implicit move. The .str() call (which flushes the
stream) is no longer required since 65b13610a5,
which made raw_string_ostream unbuffered by default.
Differential Revision: https://reviews.llvm.org/D115374
The default for min is changed to 1. The behaviour of -mvscale-{min,max}
in Clang is also changed such that 16 is the max vscale when targeting
SVE and no max is specified.
Reviewed By: sdesmalen, paulwalker-arm
Differential Revision: https://reviews.llvm.org/D113294
Currently, BeforeExecute is called before BeginSourceFile which does not allow
using PP in the callbacks. Change the ordering to ensure it is possible.
This is a prerequisite for D114370.
Originated from a discussion with @kadircet.
Reviewed By: sammccall
Differential Revision: https://reviews.llvm.org/D114525
Add an AtomicScopeModel for HIP and support for OpenCL builtins
that are missing in HIP.
Patch by: Michael Liao
Revised by: Anshil Ghandi
Reviewed by: Yaxun Liu
Differential Revision: https://reviews.llvm.org/D113925
This removes the ability to disable roundtripping in assert builds.
(Roundtripping happens by default in assert builds both before and after
this patch.)
The CLANG_ROUND_TRIP_CC1_ARGS was added as an escape hatch 9 months ago
in https://reviews.llvm.org/D97462, with a FIXME to remove it eventually.
It's probably time to remove it.
Differential Revision: https://reviews.llvm.org/D114120
With this,
void f() { __asm__("mov eax, ebx"); }
now compiles with clang with -masm=intel.
This matches gcc.
The flag is not accepted in clang-cl mode. It has no effect on
MSVC-style `__asm {}` blocks, which are unconditionally in intel
mode both before and after this change.
One difference to gcc is that in clang, inline asm strings are
"local" while they're "global" in gcc. Building the following with
-masm=intel works with clang, but not with gcc where the ".att_syntax"
from the 2nd __asm__() is in effect until file end (or until a
".intel_syntax" somewhere later in the file):
__asm__("mov eax, ebx");
__asm__(".att_syntax\nmovl %ebx, %eax");
__asm__("mov eax, ebx");
This also updates clang's intrinsic headers to work both in
-masm=att (the default) and -masm=intel modes.
The official solution for this according to "Multiple assembler dialects in asm
templates" in gcc docs->Extensions->Inline Assembly->Extended Asm
is to write every inline asm snippet twice:
bt{l %[Offset],%[Base] | %[Base],%[Offset]}
This works in LLVM after D113932 and D113894, so use that.
(Just putting `.att_syntax` at the start of the snippet works in some but not
all cases: When LLVM interpolates in parameters like `%0`, it uses at&t or
intel syntax according to the inline asm snippet's flavor, so the `.att_syntax`
within the snippet happens to late: The interpolated-in parameter is already
in intel style, and then won't parse in the switched `.att_syntax`.)
It might be nice to invent a `#pragma clang asm_dialect push "att"` /
`#pragma clang asm_dialect pop` to be able to force asm style per snippet,
so that the inline asm string doesn't contain the same code in two variants,
but let's leave that for a follow-up.
Fixes PR21401 and PR20241.
Differential Revision: https://reviews.llvm.org/D113707
Change the error message to use ignorelist, and changed some variable and function
names in related code and test.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D113189
Add new triple and target info for ‘spirv32’ and ‘spirv64’ and,
thus, enabling clang (LLVM IR) code emission to SPIR-V target.
The target for SPIR-V is mostly reused from SPIR by derivation
from a common base class since IR output for SPIR-V is mostly
the same as SPIR. Some refactoring are made accordingly.
Added and updated tests for parts that are different between
SPIR and SPIR-V.
Patch by linjamaki (Henry Linjamäki)!
Differential Revision: https://reviews.llvm.org/D109144
The PragmaAssumeNonNullHandler (and maybe others) passes an invalid
SourceLocation to its callback, hence PrintPreprocessedOutput does not
know how many lines to insert between the previous token and the
pragma and does nothing.
With this patch we instead assume that the unknown token is on the same
line as the previous such that we can call the procedure that also emits
semantically significant whitespace.
Fixes bug reported here: https://reviews.llvm.org/D104601#3105044
This is reported by msvc as
warning C6287: redundant code: the left and right subexpressions are identical
EmittedDirectiveOnThisLine implies EmittedTokensOnThisLine
making this an NFC change. To be on the safe side and because both of
them are checked at other places as well, we continue to check both.
Compiler warning reported here:
https://reviews.llvm.org/D104601#2957333
Now in libcxx and clang, all the coroutine components are defined in
std::experimental namespace.
And now the coroutine TS is merged into C++20. So in the working draft
like N4892, we could find the coroutine components is defined in std
namespace instead of std::experimental namespace.
And the coroutine support in clang seems to be relatively stable. So I
think it may be suitable to move the coroutine component into the
experiment namespace now.
This patch would make clang lookup coroutine_traits in std namespace
first. For the compatibility consideration, clang would lookup in
std::experimental namespace if it can't find definitions in std
namespace. So the existing codes wouldn't be break after update
compiler.
And in case the compiler found std::coroutine_traits and
std::experimental::coroutine_traits at the same time, it would emit an
error for it.
The support for looking up std::experimental::coroutine_traits would be
removed in Clang16.
Reviewed By: lxfind, Quuxplusone
Differential Revision: https://reviews.llvm.org/D108696
Downstream users may have Clang plugins. By default these plugins run
after the main action if they are specified on the command line.
Since these plugins are ASTConsumers, presumably they inspect the AST.
So we shouldn't clear it if any plugins run after the main action.
Reviewed By: dblaikie, hans
Differential Revision: https://reviews.llvm.org/D112190
Currently we have a way to run a plugin if specified on the command line
after the main action, and ways to unconditionally run the plugin before
or after the main action, but no way to run a plugin if specified on the
command line before the main action.
This introduces the missing option.
This is helpful because -clear-ast-before-backend clears the AST before
codegen, while some plugins may want access to the AST.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D112096
When using explicit Clang modules, some declarations might unexpectedly become invisible.
This is caused by the mechanism that loads PCM files passed via `-fmodule-file=<path>` and creates an `IdentifierInfo` for the module name. The `IdentifierInfo` creation takes place when the `ASTReader` is in a weird state, with modules that are loaded but not yet set up properly. This patch delays the creation of `IdentifierInfo` until the `ASTReader` is done with reading the PCM.
Note that the `-fmodule-file=<name>=<path>` form of the argument doesn't suffer from this issue, since it doesn't create `IdentifierInfo` for the module name.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D111543
Previously, we reported the same value as for C17, now we report 202000L, which
is the same value currently used by GCC.
Once C23 ships, this value will be bumped to the correct date.