When doing overload resolution, we have to check that candidates' parameter types are equal before trying to find a better candidate through checking which candidate is more constrained.
This revision adds this missing check and makes us diagnose those cases as ambiguous calls when the types are not equal.
Fixes GitHub issue https://github.com/llvm/llvm-project/issues/53640
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D123182
This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`, `move_if_noexcept`, `as_const`, `addressof`, and the
libstdc++-specific function `__addressof`.
We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.
This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.
We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.
In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.
The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.
This is a re-commit of
fc30901096,
a571f82a50, and
64c045e25b
which were reverted in
e75d8b7037
due to a crasher bug where CodeGen would emit a builtin glvalue as an
rvalue if it constant-folds.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D123345
We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.
This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.
We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.
In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.
The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D123345
CUDA/HIP determines whether a function can be called based on
the device/host attributes of callee and caller. Clang assumes the
caller is CurContext. This is correct in most cases, however, it is
not correct in OpenMP parallel region when CUDA/HIP program
is compiled with -fopenmp. This causes incorrect overloading
resolution and missed diagnostics.
To get the correct caller, clang needs to chase the parent chain
of DeclContext starting from CurContext until a function decl
or a lambda decl is reached. Sema API is adapted to achieve that
and used to determine the caller in hostness check.
Reviewed by: Artem Belevich, Richard Smith
Differential Revision: https://reviews.llvm.org/D121765
function candidates
See: https://github.com/llvm/llvm-project/issues/54379
I tried to see if I can reuse ResolveAddressOfOverloadedFunction for
explicit function instantiation and so I managed to hit this ICE.
Bug was the diagnostic required an argument (%0) and specific code path
didn't pass an argument.
Differential Revision: https://reviews.llvm.org/D121646
As far as I can tell, MSVC allows the relevant conversions for all
pointer types. Found compiling a Windows SDK header.
I've verified that the updated errors in MicrosoftExtensions.cpp match
the ones that MSVC actually emits, except for the one with a FIXME. (Not
sure why this wasn't done for the patch that added the tests.)
To make up for the missing error, add a warning that triggers on
conversions that drop the __unaligned qualfier.
Differential Revision: https://reviews.llvm.org/D120936
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.
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
The root cause for the crash is the incorrect use of `cast`.
The actual type and cast-to type is different. This patch fixes the
crash by converting the `cast` to `dyn_cast`.
This covers both C-style variadic functions and template variadic w/
parameter packs.
Previously we would return no signatures when working with template
variadic functions once activeParameter reached the position of the
parameter pack (except when it was the only param, then we'd still
show it when no arguments were given). With this commit, we now show
signathure help correctly.
Additionally, this commit fixes the activeParameter value in LSP output
of clangd in the presence of variadic functions (both kinds). LSP does
not allow the activeParamter to be higher than the number of parameters
in the active signature. With "..." or parameter pack being just one
argument, for all but first argument passed to "..." we'd report
incorrect activeParameter value. Clients such as VSCode would then treat
it as 0, as suggested in the spec) and highlight the wrong parameter.
In the future, we should add support for per-signature activeParamter
value, which exists in LSP since 3.16.0. This is not part of this
commit.
Differential Revision: https://reviews.llvm.org/D111318
As reported on https://pvs-studio.com/en/blog/posts/cpp/0771/ (Snippet 2) - (and mentioned on rGdc4259d5a38409) we are repeating the T1.isNull() check instead of checking T2.isNull() as well, and at this point neither should be null - so we're better off with an assertion.
Differential Revision: https://reviews.llvm.org/D107347
It seems that Clang 11 regressed functionality that was working in
Clang 10 regarding calling a few overloaded operators in an immediate
context. Specifically, we were not checking for immediate invocations
of array subscripting and the arrow operators, but we properly handle
the other overloaded operators.
This fixes the two problematic operators and adds some test coverage to
show they're equivalent to calling the operator directly.
This addresses PR50779.
This is the second part of p0388, dealing with overloads of list
initialization to incomplete array types. It extends the handling
added in D103088 to permit incomplete arrays. We have to record that
the conversion involved an incomplete array, and so (re-add) a bit flag
into the standard conversion sequence object. Comparing such
conversion sequences requires knowing (a) the number of array elements
initialized and (b) whether the initialization is of an incomplete array.
This also updates the web page to indicate p0388 is implemented (there
is no feature macro).
Differential Revision: https://reviews.llvm.org/D103908
This implements the new implicit conversion sequence to an incomplete
(unbounded) array type. It is mostly Richard Smith's work, updated to
trunk, testcases added and a few bugs fixed found in such testing.
It is not a complete implementation of p0388.
Differential Revision: https://reviews.llvm.org/D102645
Extends handling of list initialization of bounded array parameters.
This adds the missing checks on converting each initializer for both
std::initializer_list and arrays. And extends
CompareImplicitConversionSequence to compares array size, for two
conversions to array type.
As noted in this patch, there's a defect in the std concerning the
partial orderability of conversion sequences. DR2492 has a suggested
direction that will be simple to add once it (hopefully) is accepted.
Differential Revision: https://reviews.llvm.org/D103088
Currently, we have no front-end type for ppc_fp128 type in IR. PowerPC
target generates ppc_fp128 type from long double now, but there's option
(-mabi=(ieee|ibm)longdouble) to control it and we're going to do
transition from IBM extended double-double ppc_fp128 to IEEE fp128 in
the future.
This patch adds type __ibm128 which always represents ppc_fp128 in IR,
as what GCC did for that type. Without this type in Clang, compilation
will fail if compiling against future version of libstdcxx (which uses
__ibm128 in headers).
Although all operations in backend for __ibm128 is done by software,
only PowerPC enables support for it.
There's something not implemented in this commit, which can be done in
future ones:
- Literal suffix for __ibm128 type. w/W is suitable as GCC documented.
- __attribute__((mode(IF))) should be for __ibm128.
- Complex __ibm128 type.
Reviewed By: rjmccall
Differential Revision: https://reviews.llvm.org/D93377
Support Narrowing conversions to bool in if constexpr condition
under C++23 language mode.
Only if constexpr is implemented as the behavior of static_assert
is already conforming. Still need to work on explicit(bool) to
complete support.
Word on the grapevine was that the committee had some discussion that
ended with unanimous agreement on eliminating relational function pointer comparisons.
We wanted to be bold and just ban all of them cold turkey.
But then we chickened out at the last second and are going for
eliminating just the spaceship overload candidate instead, for now.
See D104680 for reference.
This should be fine and "safe", because the only possible semantic change this
would cause is that overload resolution could possibly be ambiguous if
there was another viable candidate equally as good.
But to save face a little we are going to:
* Issue an "error" for three-way comparisons on function pointers.
But all this is doing really is changing one vague error message,
from an "invalid operands to binary expression" into an
"ordered comparison of function pointers", which sounds more like we mean business.
* Otherwise "warn" that comparing function pointers like that is totally
not cool (unless we are told to keep quiet about this).
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D104892
Although clang is able to defer overloading resolution
diagnostics for common functions. It does not defer
overloading resolution caused diagnostics for overloaded
operators.
This patch extends the existing deferred
diagnostic mechanism and defers a diagnostic caused
by overloaded operator.
Reviewed by: Artem Belevich
Differential Revision: https://reviews.llvm.org/D104505
This fixes the prioritization of address spaces when choosing a
constructor, stopping them from being considered equally good,
which made the construction of types that could be constructed
by more than one of the constructors.
It does this by preferring the most specific address space,
which is decided by seeing if one of the address spaces is
a superset of the other, and preferring the other.
Fixes: PR50329
Reviewed By: Anastasia
Differential Revision: https://reviews.llvm.org/D102850
This renames the expression value categories from rvalue to prvalue,
keeping nomenclature consistent with C++11 onwards.
C++ has the most complicated taxonomy here, and every other language
only uses a subset of it, so it's less confusing to use the C++ names
consistently, and mentally remap to the C names when working on that
context (prvalue -> rvalue, no xvalues, etc).
Renames:
* VK_RValue -> VK_PRValue
* Expr::isRValue -> Expr::isPRValue
* SK_QualificationConversionRValue -> SK_QualificationConversionPRValue
* JSON AST Dumper Expression nodes value category: "rvalue" -> "prvalue"
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D103720
Drop non-conformant extension pragma implementation as
it does not properly disable anything and therefore
enabling non-disabled logic has no meaning.
This simplifies clang code and user interface to the extension
functionality. With this patch extension pragma 'begin'/'end'
and 'enable'/'disable' are only accepted for backward
compatibility and no longer have any default behavior.
Differential Revision: https://reviews.llvm.org/D101043
As of MSVC 19.28 (2019 Update 8), integral conversion is no longer preferred over floating-to-integral, and so MSVC is more standard conformant and will generate a compiler error on ambiguous call.
Cf. https://godbolt.org/z/E8xsdqKsb.
Initially found during the review of D99641.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D99663
See https://bugs.llvm.org/show_bug.cgi?id=42154.
GCC's __attribute__((align)) can reduce the alignment of a type when applied to
a typedef. However, functions which take a pointer or reference to the
original type are compiled assuming the original alignment. Therefore when any
such function is passed an object of the new, less-aligned type, an alignment
fault can occur. In particular, this applies to the constructor, which is
defined for the original type and called for the less-aligned object.
This change adds a warning whenever an pointer or reference to an object is
passed to a function that was defined for a more-aligned type.
The calls to ASTContext::getTypeAlignInChars seem change the order in which
record layouts are evaluated, which caused changes to the output of
-fdump-record-layouts. As such some tests needed to be updated:
* Use CHECK-LABEL rather than counting the number of "Dumping AST Record
Layout" headers.
* Check for end of line in labels, so that struct B1 doesn't match struct B
etc.
* Add --strict-whitespace, since the whitespace shows meaningful structure.
* The order in which record layouts are printed has changed in some cases.
* clang-format for regions changed
Differential Revision: https://reviews.llvm.org/D97187
Previously, -fshow-overloads=best always showed 4 candidates. The
problem is, when this isn't enough, you're kind of up a creek; the only
option available is to recompile with different flags. This can be
quite expensive!
With this change, we try to strike a compromise. The *first* error with
more than 4 candidates will show up to 32 candidates. All further
errors continue to show only 4 candidates.
The hope is that this way, users will have *some chance* of making
forward progress, without facing unbounded amounts of error spam.
Differential Revision: https://reviews.llvm.org/D95754
Combined with 'da98651 - Revert "DR2064:
decltype(E) is only a dependent', this change (5a391d3) caused verifier
errors when building Chromium. See https://crbug.com/1168494#c1 for a
reproducer.
Additionally it reverts changes that were dependent on this one, see
below.
> Following up on PR48517, fix handling of template arguments that refer
> to dependent declarations.
>
> Treat an id-expression that names a local variable in a templated
> function as being instantiation-dependent.
>
> This addresses a language defect whereby a reference to a dependent
> declaration can be formed without any construct being value-dependent.
> Fixing that through value-dependence turns out to be problematic, so
> instead this patch takes the approach (proposed on the core reflector)
> of allowing the use of pointers or references to (but not values of)
> dependent declarations inside value-dependent expressions, and instead
> treating template arguments as dependent if they evaluate to a constant
> involving such dependent declarations.
>
> This ends up affecting a bunch of OpenMP tests, due to OpenMP
> imprecisely handling instantiation-dependent constructs, bailing out
> early instead of processing dependent constructs to the extent possible
> when handling the template.
>
> Previously committed as 8c1f2d15b8, and
> reverted because a dependency commit was reverted.
This reverts commit 5a391d38ac.
It also restores clang/test/SemaCXX/coroutines.cpp to its state before
da986511fb.
Revert "[c++20] P1907R1: Support for generalized non-type template arguments of scalar type."
> Previously committed as 9e08e51a20, and
> reverted because a dependency commit was reverted. This incorporates the
> following follow-on commits that were also reverted:
>
> 7e84aa1b81 by Simon Pilgrim
> ed13d8c667 by me
> 95c7b6cadb by Sam McCall
> 430d5d8429 by Dave Zarzycki
This reverts commit 4b574008ae.
Revert "[msabi] Mangle a template argument referring to array-to-pointer decay"
> [msabi] Mangle a template argument referring to array-to-pointer decay
> applied to an array the same as the array itself.
>
> This follows MS ABI, and corrects a regression from the implementation
> of generalized non-type template parameters, where we "forgot" how to
> mangle this case.
This reverts commit 18e093faf7.
Previously committed as 9e08e51a20, and
reverted because a dependency commit was reverted. This incorporates the
following follow-on commits that were also reverted:
7e84aa1b81 by Simon Pilgrim
ed13d8c667 by me
95c7b6cadb by Sam McCall
430d5d8429 by Dave Zarzycki
to dependent declarations.
Treat an id-expression that names a local variable in a templated
function as being instantiation-dependent.
This addresses a language defect whereby a reference to a dependent
declaration can be formed without any construct being value-dependent.
Fixing that through value-dependence turns out to be problematic, so
instead this patch takes the approach (proposed on the core reflector)
of allowing the use of pointers or references to (but not values of)
dependent declarations inside value-dependent expressions, and instead
treating template arguments as dependent if they evaluate to a constant
involving such dependent declarations.
This ends up affecting a bunch of OpenMP tests, due to OpenMP
imprecisely handling instantiation-dependent constructs, bailing out
early instead of processing dependent constructs to the extent possible
when handling the template.
Previously committed as 8c1f2d15b8, and
reverted because a dependency commit was reverted.
to dependent declarations.
Treat an id-expression that names a local variable in a templated
function as being instantiation-dependent.
This addresses a language defect whereby a reference to a dependent
declaration can be formed without any construct being value-dependent.
Fixing that through value-dependence turns out to be problematic, so
instead this patch takes the approach (proposed on the core reflector)
of allowing the use of pointers or references to (but not values of)
dependent declarations inside value-dependent expressions, and instead
treating template arguments as dependent if they evaluate to a constant
involving such dependent declarations.
This ends up affecting a bunch of OpenMP tests, due to OpenMP
imprecisely handling instantiation-dependent constructs, bailing out
early instead of processing dependent constructs to the extent possible
when handling the template.
Emit error for use of 128-bit integer inside device code had been
already implemented in https://reviews.llvm.org/D74387. However,
the error is not emitted for SPIR64, because for SPIR64, hasInt128Type
return true.
hasInt128Type: is also used to control generation of certain 128-bit
predefined macros, initializer predefined 128-bit integer types and
build 128-bit ArithmeticTypes. Except predefined macros, only the
device target is considered, since error only emit when 128-bit
integer is used inside device code, the host target (auxtarget) also
needs to be considered.
The change address:
1. (SPIR.h) Correct hasInt128Type() for SPIR targets.
2. Sema.cpp and SemaOverload.cpp: Add additional check to consider host
target(auxtarget) when call to hasInt128Type. So that __int128_t
and __int128() are allowed to avoid error when they used outside
device code.
3. SemaType.cpp: add check for SYCLIsDevice to delay the error message.
The error will be emitted if the use of 128-bit integer in the device
code.
Reviewed By: Johannes Doerfert and Aaron Ballman
Differential Revision: https://reviews.llvm.org/D92439
I have a patch that adds another group of candidate types to
BuiltinCandidateTypeSet. Currently two styles are in use: the older
begin/end pairs and the newer iterator_range approach. I think the
group of candidates that I want to add should use iterator ranges,
but I'd also like to consolidate the handling of the new candidates
with some existing code that uses begin/end pairs. This patch therefore
converts the begin/end pairs to iterator ranges as a first step.
No functional change intended.
Differential Revision: https://reviews.llvm.org/D92222
Fix bogus diagnostics that would get confused and think a "no viable
fuctions" case was an "undeclared identifiers" case, resulting in an
incorrect diagnostic preceding the correct one. Use overload resolution
to determine which function we should select when we can find call
candidates from a dependent base class. Make the diagnostics for a call
that could call a function from a dependent base class more specific,
and use a different diagnostic message for the case where the call
target is instead declared later in the same class. Plus some minor
diagnostic wording improvements.
Roy Jacobson