The standard requires[0] member function constraints to be checked when
explicitly instantiating classes. This patch adds this constraints
check.
This issue is tracked as #46029 [1].
Note that there's an related open CWG issue (2421[2]) about what to do when
multiple candidates have satisfied constraints. This is particularly an
issue because mangling doesn't contain function constraints, and so the
following code still ICEs with definition with same mangled name
'_ZN1BIiE1fEv' as another definition:
template<class T>
struct B {
int f() requires std::same_as<T, int> {
return 0;
}
int f() requires (std::same_as<T, int> &&
!std::same_as<T, char>) {
return 1;
}
};
template struct B<int>;
Also note that the constraints checking while instantiating *functions*
is still not implemented. I started looking at it but It's a bit more
complicated. I believe in such a case we have to consider the partial
constraints order and potentially choose the best candidate out of the
set of multiple valid ones.
[0]: https://eel.is/c++draft/temp.explicit#10
[1]: https://github.com/llvm/llvm-project/issues/46029
[2]: https://cplusplus.github.io/CWG/issues/2421.html
Differential Revision: https://reviews.llvm.org/D120255
Previously, we didin't build a DeclRefExpr which refers to an invalid declaration.
In this patch, we handle this case by building an empty RecoveryExpr,
which will preserve more broken code (AST parent nodes that contain the
RecoveryExpr is preserved in the AST).
Differential Revision: https://reviews.llvm.org/D120812
C++20 non-type template parameter prints `MyType<{{116, 104, 105, 115}}>` when the code is as simple as `MyType<"this">`. This patch prints `MyType<{"this"}>`, with one layer of braces preserved for the intermediate structural type to trigger CTAD.
`StringLiteral` handles this case, but `StringLiteral` inside `APValue` code looks like a circular dependency. The proposed patch implements a cheap strategy to emit string literals in diagnostic messages only when they are readable and fall back to integer sequences.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D115031
This is used a few places in SemaTeplateInstantiateDecl, but is going
to be useful in SemaConcept.cpp as well. This patch switches it to be
a private function in Sema.
Differential Revision: https://reviews.llvm.org/D120729
Implementation partitions bring two extra cases where we have
visibility of module-private data.
1) When we import a module implementation partition.
2) When a partition implementation imports the primary module intertace.
We maintain a record of direct imports into the current module since
partition decls from direct imports (but not trasitive ones) are visible.
The rules on decl-reachability are much more relaxed (with the standard
giving permission for an implementation to load dependent modules and for
the decls there to be reachable, but not visible).
Differential Revision: https://reviews.llvm.org/D118599
Motivation:
```
int foo(int x, int y) { // any compiler will happily inline this function
return x / y;
}
int test(int x, int y) {
int r = 0;
[[clang::noinline]] r += foo(x, y); // for some reason we don't want any inlining here
return r;
}
```
In 2018, @kuhar proposed "Introduce per-callsite inline intrinsics" in https://reviews.llvm.org/D51200 to solve this motivation case (and many others).
This patch solves this problem with call site attribute. The implementation is "smaller" wrt approach which uses new intrinsics and thanks to https://reviews.llvm.org/D79121 (Add nomerge statement attribute to clang), we have got some basic infrastructure to deal with attrs on statements with call expressions.
GCC devs are more inclined to call attribute solution as well, as builtins are problematic for them - https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104187. But they have no patch proposal yet so.. We have free hands here.
If this approach makes sense, next future steps would be support for call site attributes for always_inline / flatten.
Reviewed By: aaron.ballman, kuhar
Differential Revision: https://reviews.llvm.org/D119061
When we are building modules, there are cases where the only way to determine
validity of access is by comparing primary interface names. This is because we need
to be able to associate a primary interface name with an imported partition, but
before the primary interface module is complete - so that textual comparison is
necessary.
If this turns out to be needed many times, we could cache the result, but it seems
unlikely to be significant (at this time); cases with very many imported partitions
would seem unusual.
Differential Revision: https://reviews.llvm.org/D118598
We cannot export partition implementation CMIs, but we can export the content
of partition interface CMIs.
Differential Revision: https://reviews.llvm.org/D118588
Value-dependent ConstantExprs are not meant to be evaluated.
There is an assert in Expr::EvaluateAsConstantExpr that ensures this condition.
But before this patch the method was called without prior check.
Fixes https://github.com/llvm/llvm-project/issues/52768
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D119375
Partition implementations are special, they generate a CMI, but it
does not have an 'export' line, and we cannot export anything from the
it [that is it can only make decls available to other members of the
owning module, not to importers of that].
Add initial testcases for partition handling, derived from the examples in
Section 10 of the C++20 standard, which identifies what should be accepted
and/or rejected.
Differential Revision: https://reviews.llvm.org/D118587
The `objc_precise_lifetime` attribute is applied to Objective-C pointers to ensure the optimizer does not prematurely release an object under Automatic Reference Counting (ARC). It is a common enough pattern to assign values to these variables but not reference them otherwise, and annotating them with `__unused` is not really correct as they are being used to ensure an object's lifetime.
Differential Revision: https://reviews.llvm.org/D120372
This adds a diagnostic when an unqualified call is resolved
to std::move or std::forward.
This follows some C++ committee discussions where some
people where concerns that this might be an usual anti pattern
particularly britle worth warning about - both because move
is a common name and because these functions accept any values.
This warns inconditionnally of whether the current context is in
std:: or not, as implementations probably want to always qualify
these calls too, to avoid triggering adl accidentally.
Differential Revision: https://reviews.llvm.org/D119670
This implements the parsing and recognition of module partition CMIs
and removes the FIXMEs in the parser.
Module partitions are recognised in the base computation of visibility,
however additional amendments to visibility follow in subsequent patches.
Differential Revision: https://reviews.llvm.org/D118586
Currently when we generate OpenMP offloading code we always make
fallback code for the CPU. This is necessary for implementing features
like conditional offloading and ensuring that unhandled pragmas don't
result in missing symbols. However, this is problematic for a few cases.
For offloading tests we can silently fail to the host without realizing
that offloading failed. Additionally, this makes it impossible to
provide interoperabiility to other offloading schemes like HIP or CUDA
because those methods do not provide any such host fallback guaruntee.
this patch adds the `-fopenmp-offload-mandatory` flag to prevent
generating the fallback symbol on the CPU and instead replaces the
function with a dummy global and the failed branch with 'unreachable'.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D120353
Until now, subgroup builtins are available with `opencl-c.h` when at
least one of `cl_intel_subgroups`, `cl_khr_subgroups`, or
`__opencl_c_subgroups` is defined. With `-fdeclare-opencl-builtins`,
subgroup builtins are conditionalized on `cl_khr_subgroups` only.
Align `-fdeclare-opencl-builtins` to `opencl-c.h` by introducing the
internal `__opencl_subgroup_builtins` macro.
Differential Revision: https://reviews.llvm.org/D120254
Otherwise callers of these functions have to check both the return value
for and the contents of the returned llvm::Optional.
Fixes#53742
Differential Revision: https://reviews.llvm.org/D119525
This is an initial enabling patch for module partition support.
We add enumerations for partition interfaces/implementations.
This means that the module kind enumeration now occupies three
bits, so the AST streamer is adjusted for this. Adding one bit there
seems preferable to trying to overload the meanings of existing
kinds (and we will also want to add a C++20 header unit case later).
Differential Revision: https://reviews.llvm.org/D114714
We need to capture the local variables into a record in task untied
regions but clang does not support record with VLA data members.
Differential Revision: https://reviews.llvm.org/D99436
In 'cond-update-stmt', `else` statement is not expected. This patch adds
the check in Sema.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D120225
In C++20 modules imports must be together and at the start of the module.
Rather than growing more ad-hoc flags to test state, this keeps track of the
phase of of a valid module TU (first decl, global module frag, module,
private module frag). If the phasing is broken (with some diagnostic) the
pattern does not conform to a valid C++20 module, and we set the state
accordingly.
We can thus issue diagnostics when imports appear in the wrong places and
decouple the C++20 modules state from other module variants (modules-ts and
clang modules). Additionally, we attempt to diagnose wrong imports before
trying to find the module where possible (the latter will generally emit an
unhelpful diagnostic about the module not being available).
Although this generally simplifies the handling of C++20 module import
diagnostics, the motivation was that, in particular, it allows detecting
invalid imports like:
import module A;
int some_decl();
import module B;
where being in a module purview is insufficient to identify them.
Differential Revision: https://reviews.llvm.org/D118893
In C++20 modules imports must be together and at the start of the module.
Rather than growing more ad-hoc flags to test state, this keeps track of the
phase of of a valid module TU (first decl, global module frag, module,
private module frag). If the phasing is broken (with some diagnostic) the
pattern does not conform to a valid C++20 module, and we set the state
accordingly.
We can thus issue diagnostics when imports appear in the wrong places and
decouple the C++20 modules state from other module variants (modules-ts and
clang modules). Additionally, we attempt to diagnose wrong imports before
trying to find the module where possible (the latter will generally emit an
unhelpful diagnostic about the module not being available).
Although this generally simplifies the handling of C++20 module import
diagnostics, the motivation was that, in particular, it allows detecting
invalid imports like:
import module A;
int some_decl();
import module B;
where being in a module purview is insufficient to identify them.
Differential Revision: https://reviews.llvm.org/D118893
This patch adds the support for `atomic compare capture` in parser and part of
sema. We don't create an AST node for this because the spec doesn't say `compare`
and `capture` clauses should be used tightly, so we cannot look one more token
ahead in the parser.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D116261
When an a variant is specified that is the same as the base function
the compiler will end up crashing in CodeGen. Give an error instead.
Differential Revision: https://reviews.llvm.org/D119979
Until now, overloads with a 64-bit atomic type argument were always
made available with `-fdeclare-opencl-builtins`. Ensure these
overloads are only available when both the `cl_khr_int64_base_atomics`
and `cl_khr_int64_extended_atomics` extensions have been enabled, as
required by the OpenCL specification.
Differential Revision: https://reviews.llvm.org/D119858
The named and generic address space overloads for atomic_init added
by 50f8abb9f4 ("[OpenCL] Add OpenCL 3.0 atomics to
-fdeclare-opencl-builtins", 2022-02-11) were not guarded by the
corresponding extensions.
This patch tries to implement RVO for coroutine's return object got from
get_return_object.
From [dcl.fct.def.coroutine]/p7 we could know that the return value of
get_return_object is either a reference or a prvalue. So it makes sense
to do copy elision for the return value. The return object should be
constructed directly into the storage where they would otherwise be
copied/moved to.
Test Plan: folly, check-all
Reviewed By: junparser
Differential revision: https://reviews.llvm.org/D117087
constexpr var may be initialized with address of non-const variable.
In this case the initializer is not constant in device compilation.
This has been handled for const vars but not for constexpr vars.
This patch makes handling of const var and constexpr var
consistent.
Reviewed by: Artem Belevich
Differential Revision: https://reviews.llvm.org/D119615
Fixes: https://github.com/llvm/llvm-project/issues/53780
The `__builtin_pdepd` and `__builtin_pextd` are P10 builtins that are meant to
be used under 64-bit only. For instance, when the builtins are compiled under
32-bit mode:
```
$ cat t.c
unsigned long long foo(unsigned long long a, unsigned long long b) {
return __builtin_pextd(a,b);
}
$ clang -c t.c -mcpu=pwr10 -m32
ExpandIntegerResult #0: t31: i64 = llvm.ppc.pextd TargetConstant:i32<6928>, t28, t29
fatal error: error in backend: Do not know how to expand the result of this operator!
```
This patch adds sema checking for these builtins to compile under 64-bit
mode only and on P10. The builtins will emit a diagnostic when they are compiled on
non-P10 compilations and on 32-bit mode.
Differential Revision: https://reviews.llvm.org/D118753
Post-commit review feedback suggested dropping the deprecated
diagnostic for the 'noreturn' macro (the diagnostic from the header
file suffices and the macro diagnostic could be confusing) and to only
issue the deprecated diagnostic for [[_Noreturn]] when the attribute
identifier is either directly written or not from a system macro.
Amends the commit made in 5029dce492.
when the function declaration's return type is already invalid for
some reason. This is relevant to https://github.com/llvm/llvm-project/issues/49188
because another way that the declaration's return type could become
invalid is that it might be `C auto` where `C<void>` is false.
Differential Revision: https://reviews.llvm.org/D119094
This adds support for http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2764.pdf,
which was adopted at the Feb 2022 WG14 meeting. That paper adds
[[noreturn]] and [[_Noreturn]] to the list of supported attributes in
C2x. These attributes have the same semantics as the [[noreturn]]
attribute in C++.
The [[_Noreturn]] attribute was added as a deprecated feature so that
translation units which include <stdnoreturn.h> do not get an error on
use of [[noreturn]] because the macro expands to _Noreturn. Users can
use -Wno-deprecated-attributes to silence the diagnostic.
Use of <stdnotreturn.h> or the noreturn macro were both deprecated.
Users can define the _CLANG_DISABLE_CRT_DEPRECATION_WARNINGS macro to
suppress the deprecation diagnostics coming from the header file.
When forming the function type from a declarator, we look for an
overloadable attribute before issuing a diagnostic in C about a
function signature containing only .... When the attribute is present,
we allow such a declaration for compatibility with the overloading
rules in C++. However, we were not looking for the attribute in all of
the places it is legal to write it on a declarator and so we only
accepted the signature in some forms and incorrectly rejected the
signature in others.
We now check for the attribute preceding the declarator instead of only
being applied to the declarator directly.
OpenCL C 3.0 __opencl_c_subgroups feature is slightly different
then other equivalent features and extensions (fp64 and 3d image writes):
OpenCL C 3.0 device can support the extension but not the feature.
cl_khr_subgroups requires subgroup independent forward progress.
This patch adjusts the check which is used when translating language
builtins to check either the extension or feature is supported.
Reviewed By: Anastasia
Differential Revision: https://reviews.llvm.org/D118999
Add the atomic overloads for the `global` and `local` address spaces,
which are new in OpenCL 3.0. Ensure the preexisting `generic`
overloads are guarded by the generic address space feature macro.
Ensure a subset of the atomic builtins are guarded by the
`__opencl_c_atomic_order_seq_cst` and `__opencl_c_atomic_scope_device`
feature macros, and enable those macros for SPIR/SPIR-V targets in
`opencl-c-base.h`.
Also guard the `cl_ext_float_atomics` builtins with the atomic order
and scope feature macros.
Differential Revision: https://reviews.llvm.org/D119420
Reduce the amount of repetition in the declarations by leveraging more
TableGen constructs. This is in preparation for adding the OpenCL 3.0
atomics feature optionality.
An error in the tablegen description affects the declarations
provided by `-fdeclare-opencl-builtins` for `atomic_fetch_add` and
`atomic_fetch_sub`.
The atomic argument should be an atomic_half, not an atomic_float.
The "-fzero-call-used-regs" option tells the compiler to zero out
certain registers before the function returns. It's also available as a
function attribute: zero_call_used_regs.
The two upper categories are:
- "used": Zero out used registers.
- "all": Zero out all registers, whether used or not.
The individual options are:
- "skip": Don't zero out any registers. This is the default.
- "used": Zero out all used registers.
- "used-arg": Zero out used registers that are used for arguments.
- "used-gpr": Zero out used registers that are GPRs.
- "used-gpr-arg": Zero out used GPRs that are used as arguments.
- "all": Zero out all registers.
- "all-arg": Zero out all registers used for arguments.
- "all-gpr": Zero out all GPRs.
- "all-gpr-arg": Zero out all GPRs used for arguments.
This is used to help mitigate Return-Oriented Programming exploits.
Reviewed By: nickdesaulniers
Differential Revision: https://reviews.llvm.org/D110869
The above change assumed that malloc (and friends) would always
allocate memory to getNewAlign(), even for allocations which have a
smaller size. This is not actually required by spec (a 1-byte
allocation may validly have 1-byte alignment).
Some real-world malloc implementations do not provide this guarantee,
and thus this optimization is breaking programs.
Fixes#53540
This reverts commit c2297544c0.
Differential Revision: https://reviews.llvm.org/D118804
These changes make the Clang parser recognize expression parameter pack
expansion and initializer lists in attribute arguments. Because
expression parameter pack expansion requires additional handling while
creating and instantiating templates, the support for them must be
explicitly supported through the AcceptsExprPack flag.
Handling expression pack expansions may require a delay to when the
arguments of an attribute are correctly populated. To this end,
attributes that are set to accept these - through setting the
AcceptsExprPack flag - will automatically have an additional variadic
expression argument member named DelayedArgs. This member is not
exposed the same way other arguments are but is set through the new
CreateWithDelayedArgs creator function generated for applicable
attributes.
To illustrate how to implement support for expression pack expansion
support, clang::annotate is made to support pack expansions. This is
done by making handleAnnotationAttr delay setting the actual attribute
arguments until after template instantiation if it was unable to
populate the arguments due to dependencies in the parsed expressions.
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.
Done in manner similar to mutexinoutset
(see https://reviews.llvm.org/D57576)
Runtime support already exists in LLVM OpenMP runtime (see
https://reviews.llvm.org/D97085).
The value used to identify an inoutset dependency type in the LLVM
OpenMP runtime is 8.
Some tests updated due to change in dependency type error messages that
now include new dependency type. Also updated
test/OpenMP/task_codegen.cpp to verify we emit the right code.
This patch implements `__builtin_elementwise_add_sat` and `__builtin_elementwise_sub_sat` builtins.
These map to the add/sub saturated math intrinsics described here:
https://llvm.org/docs/LangRef.html#saturation-arithmetic-intrinsics
With this in place we should then be able to replace the x86 SSE adds/subs intrinsics with these generic variants - it looks like other targets should be able to use these as well (arm/aarch64/webassembly all have similar examples in cgbuiltin).
Differential Revision: https://reviews.llvm.org/D117898
Since the serialization code would recognize modules by names and the
name of all global module fragment is <global>, so that the
serialization code would complain for the same module.
This patch fixes this by using a unique global module fragment in Sema.
Before this patch, the compiler would fail on an assertion complaining
the duplicated modules.
Reviewed By: urnathan, rsmith
Differential Revision: https://reviews.llvm.org/D115610
See the discussion in https://reviews.llvm.org/D100282. The coroutine
marked always inline might not be inlined properly in current compiler
support. Since the coroutine would be splitted into pieces. And the call
to resume() and destroy() functions might be indirect call. Also the
ramp function wouldn't get inlined under O0 due to pipeline ordering
problems. It might be different to what users expects to. Emit a warning
to tell it.
This is what GCC does too: https://godbolt.org/z/7eajb1Gf8
Reviewed By: Quuxplusone
Differential Revision: https://reviews.llvm.org/D115867
This reverts commit 852afed5e0.
Changes since D114732:
On PS4, we reverse the expectation that classes whose constructor is deleted are not trivially relocatable. Because, at the moment, only classes which are passed in registers are trivially relocatable, and PS4 allows passing in registers if the copy constructor is deleted, the original assertions were broken on PS4.
(This is kinda similar to DR1734.)
Reviewed By: gribozavr2
Differential Revision: https://reviews.llvm.org/D119017
OpenMP Spec 5.0 [2.12.5, Restrictions]: If a device clause in which the
ancestor device-modifier appears is present on the target construct,
then a requires directive with the reverse_offload clause must be
specified.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D118887
This will simplify future conditionalization for OpenCL 3.0
optionality of atomic features.
The only set of atomic functions not using the multiclass is
atomic_compare_exchange_strong/weak, as these don't fit the common
pattern due to having 2 MemoryOrder arguments.
This change enables library code to skip paired move-construction and destruction for `trivial_abi` types, as if they were trivially-movable and trivially-destructible. This offers an extension to the performance fix offered by `trivial_abi`: rather than only offering trivial-type-like performance for pass-by-value, it also offers it for library code that moves values but not as arguments.
For example, if we use `memcpy` for trivially relocatable types inside of vector reallocation, and mark `unique_ptr` as `trivial_abi` (via `_LIBCPP_ABI_ENABLE_UNIQUE_PTR_TRIVIAL_ABI` / `_LIBCPP_ABI_UNSTABLE` / etc.), this would speed up `vector<unique_ptr>::push_back` by 40% on my benchmarks. (Though note that in this case, the compiler could have done this anyway, but happens not to due to the inlining horizon.)
If accepted, I intend to follow up with exactly such changes to library code, including and especially `std::vector`, making them use a trivial relocation operation on trivially relocatable types.
**D50119 and P1144:**
This change is very similar to D50119, which was rejected from Clang. (That change was an implementation of P1144, which is not yet part of the C++ standard.)
The intent of this change, rather than trying to pick a winning proposal for trivial relocation operations, is to extend the behavior of `trivial_abi` in a way that could be made compatible with any such proposal. If P1144 or any similar proposal were accepted, then `trivial_abi`, `__is_trivially_relocatable`, and everything else in this change would be redefined in terms of that.
**Safety:**
It's worth pointing out, specifically, that `trivial_abi` already implies trivial relocatability in a narrow sense: a `trivial_abi` type, when passed by value, has its constructor run in one location, and its destructor run in another, after the type has been trivially relocated (through registers).
Trivial relocatability optimizations could change the number of paired constructor/destructor calls, but this seems unlikely to matter for `trivial_abi` types.
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D114732
If this is a SFINAE context, then continuing to look up names
(in particular, to treat a non-function as a function, and then
do ADL) might too-eagerly complete a type that it's not safe to
complete right now. We should just say "okay, that's a substitution
failure" and not do any more work than absolutely required.
Fixes#52970.
Differential Revision: https://reviews.llvm.org/D117603
Bug #52905 was originally papered over in a different way, but
I believe this is the actually proper fix, or at least closer to
it. We need to detect placeholder types as close to the front-end
as possible, and cause them to fail constraints, rather than letting
them persist into later stages.
Fixes#52905.
Fixes#52909.
Fixes#53075.
Differential Revision: https://reviews.llvm.org/D118552
Some functions can end up non-externally visible despite not being
declared "static" or in an unnamed namespace in C++ - such as by having
parameters that are of non-external types.
Such functions aren't mistakenly intended to be defining some function
that needs a declaration. They could be maybe more legible (except for
the `operator new` example) with an explicit static, but that's a
stylistic thing outside what should be addressed by a warning.
When the stepsize does not evenly divide the range's end, round-up to ensure that that last multiple of the stepsize before the reaching the upper boud is reached. For instance, the trip count of
for (int i = 0; i < 7; i+=5)
is two (i=0 and i=5), not (7-0)/5 == 1.
Reviewed By: peixin
Differential Revision: https://reviews.llvm.org/D118542
Currently, -fdeclare-opencl-builtins always adds the generic address
space overloads of e.g. the vload builtin functions in OpenCL 3.0
mode, even when the generic address space feature is disabled.
Guard the generic address space overloads by the
`__opencl_c_generic_address_space` feature instead of by OpenCL
version.
Guard the private, global, and local overloads using the internal
`__opencl_c_named_address_space_builtins` feature.
Differential Revision: https://reviews.llvm.org/D107769
Do not warn on reserved identifiers resulting from expansion of system macros.
Also properly test -Wreserved-identifier wrt. system headers.
Should fix#49592
Differential Revision: https://reviews.llvm.org/D118532
Currently clang treats host var address as constant in device compilation,
which causes const vars initialized with host var address promoted to
device variables incorrectly and results in undefined symbols.
This patch fixes that.
Reviewed by: Artem Belevich
Differential Revision: https://reviews.llvm.org/D118153
Fixes: SWDEV-309881
Change-Id: I0a69357063c6f8539ef259c96c250d04615f4473
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.
Branch protection in M-class is supported by
- Armv8.1-M.Main
- Armv8-M.Main
- Armv7-M
Attempting to enable this for other architectures, either by
command-line (e.g -mbranch-protection=bti) or by target attribute
in source code (e.g. __attribute__((target("branch-protection=..."))) )
will generate a warning.
In both cases function attributes related to branch protection will not
be emitted. Regardless of the warning, module level attributes related to
branch protection will be emitted when it is enabled via the command-line.
The following people also contributed to this patch:
- Victor Campos
Reviewed By: chill
Differential Revision: https://reviews.llvm.org/D115501
If this is a SFINAE context, then continuing to look up names
(in particular, to treat a non-function as a function, and then
do ADL) might too-eagerly complete a type that it's not safe to
complete right now. We should just say "okay, that's a substitution
failure" and not do any more work than absolutely required.
Fixes#52970.
Differential Revision: https://reviews.llvm.org/D117603
Corentin Jabot