This includes a fix for the libc++ issue I ran across with friend
declarations not properly being identified as overloads.
This reverts commit 45c07db31c.
This reverts commit a97899108e.
The patch caused some problems with the libc++ `__range_adaptor_closure`
that I haven't been able to figure out the cause of, so I am reverting
while I figure out whether this is a solvable problem/issue with the
CFE, or libc++ depending on an older 'incorrect' behavior.
This reverts commit 0c31da4838.
I've solved the issue with the PointerUnion by making the
`FunctionTemplateDecl` pointer be a NamedDecl, that could be a
`FunctionDecl` or `FunctionTemplateDecl` depending. This is enforced
with an assert.
This reverts commit 4b6c2cd647.
The patch caused numerous ARM 32 bit build failures, since we added a
5th item to the PointerUnion, and went over the 2-bits available in the
32 bit pointers.
As reported here: https://github.com/llvm/llvm-project/issues/44178
Concepts are not supposed to be instantiated until they are checked, so
this patch implements that and goes through significant amounts of work
to make sure we properly re-instantiate the concepts correctly.
Differential Revision: https://reviews.llvm.org/D119544
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,
64c045e25b, and
de6ddaeef3,
and reverts aa643f455a.
This change also includes a workaround for users using libc++ 3.1 and
earlier (!!), as apparently happens on AIX, where std::move sometimes
returns by value.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D123345
Revert "Fixup D123950 to address revert of D123345"
This reverts commit aa643f455a.
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
We did not implement C99 6.7.5.3p15 fully in that we missed the rule
for compatible function types where a prior declaration has a prototype
and a subsequent definition (not just declaration) has an empty
identifier list or an identifier list with a mismatch in parameter
arity. This addresses that situation by issuing an error on code like:
void f(int);
void f() {} // type conflicts with previous declaration
(Note: we already diagnose the other type conflict situations
appropriately, this was the only situation we hadn't covered that I
could find.)
InstantiateDefaultCtorDefaultArgs() is supposed to mark default
constructor args as odr-used, since those args will be used when
emitting the constructor closure.
However, constexpr vars were not getting odr-used since
DoMarkVarDeclReferenced() defers them in MaybeODRUseExprs, and the code
was calling CleanupVarDeclMarking() which discarded those uses instead
of processing them.
(This came up in Chromium, crbug.com/1312086)
Differential revision: https://reviews.llvm.org/D123405
This builtin returns the address of a global instance of the
`std::source_location::__impl` type, which must be defined (with an
appropriate shape) before calling the builtin.
It will be used to implement std::source_location in libc++ in a
future change. The builtin is compatible with GCC's implementation,
and libstdc++'s usage. An intentional divergence is that GCC declares
the builtin's return type to be `const void*` (for
ease-of-implementation reasons), while Clang uses the actual type,
`const std::source_location::__impl*`.
In order to support this new functionality, I've also added a new
'UnnamedGlobalConstantDecl'. This artificial Decl is modeled after
MSGuidDecl, and is used to represent a generic concept of an lvalue
constant with global scope, deduplicated by its value. It's possible
that MSGuidDecl itself, or some of the other similar sorts of things
in Clang might be able to be refactored onto this more-generic
concept, but there's enough special-case weirdness in MSGuidDecl that
I gave up attempting to share code there, at least for now.
Finally, for compatibility with libstdc++'s <source_location> header,
I've added a second exception to the "cannot cast from void* to T* in
constant evaluation" rule. This seems a bit distasteful, but feels
like the best available option.
Reviewers: aaron.ballman, erichkeane
Differential Revision: https://reviews.llvm.org/D120159
Partially fixes PR24883.
The patch sets Reference bit while instantiating a typedef if it
previously was found referenced.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D114382
This is a Sema function that now no longer depends on any of the
functionality in SemaTemplateInstantiateDecl.cpp (as the static function
was moved to Sema in a previous NFC). Moving it to SemaConcept means
that it and CheckFunctionConstraints can be changed to share more.
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
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.
Back in the mists of time, the CXXRecordDecl for the injected-class-name was
a redecl of the outer class itself.
This got changed in 470c454a61, but only for plain
classes: class template instantation was still detecting the injected-class-name
in the template body and marking its instantiation as a redecl.
This causes some subtle inconsistent behavior between the two, e.g.
hasDefinition() returns true for Foo<int>::Foo but false for Bar::Bar.
This is the root cause of PR51912.
Differential Revision: https://reviews.llvm.org/D112765
Adds initial parsing and sema for the 'append_args' clause.
Note that an AST clause is not created as it instead adds its values
to the OMPDeclareVariantAttr.
Differential Revision: https://reviews.llvm.org/D111854
Adds initial parsing and sema for the 'adjust_args' clause.
Note that an AST clause is not created as it instead adds its expressions
to the OMPDeclareVariantAttr.
Differential Revision: https://reviews.llvm.org/D99905
After significant problems in our downstream with the previous
implementation, the SYCL standard has opted to make using macros/etc to
change kernel-naming-lambdas in any way UB (even passively). As a
result, we are able to just emit the itanium mangling.
However, this DOES require a little work in the CXXABI, as the microsoft
and itanium mangler use different numbering schemes for lambdas. This
patch adds a pair of mangling contexts that use the normal 'itanium'
mangling strategy to fill in the "DeviceManglingNumber" used previously
by CUDA.
Differential Revision: https://reviews.llvm.org/D110281
See PR51708.
Attempting copy elision in dependent contexts with invalid variable,
such as a variable with incomplete type, would cause a crash when attempting
to calculate it's alignment.
The fix is to just skip this optimization on invalid VarDecl, as otherwise this
provides no benefit to error recovery: This functionality does not try to
diagnose anything, it only calculates a flag which will affect where the
variable will be allocated during codegen.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: rtrieu
Differential Revision: https://reviews.llvm.org/D109191
@kpn pointed out that the global variable initialization functions didn't
have the "strictfp" metadata set correctly, and @rjmccall said that there
was buggy code in SetFPModel and StartFunction, this patch is to solve
those problems. When Sema creates a FunctionDecl, it sets the
FunctionDeclBits.UsesFPIntrin to "true" if the lexical FP settings
(i.e. a combination of command line options and #pragma float_control
settings) correspond to ConstrainedFP mode. That bit is used when CodeGen
starts codegen for a llvm function, and it translates into the
"strictfp" function attribute. See bugs.llvm.org/show_bug.cgi?id=44571
Reviewed By: Aaron Ballman
Differential Revision: https://reviews.llvm.org/D102343
During template instantiation involving templated lambdas, clang
could hit an assertion in `TemplateDeclInstantiator::SubstFunctionType`
since the functions are not associated with any `TypeSourceInfo`:
`assert(OldTInfo && "substituting function without type source info");`
This path is triggered when using templated lambdas like the one added as
a test to this patch. To fix this:
- Create `TypeSourceInfo`s for special members and make sure the template
instantiator can get through all patterns.
- Introduce a `SpecialMemberTypeInfoRebuilder` tree transform to rewrite
such member function arguments. Without this, we get errors like:
`error: only special member functions and comparison operators may be defaulted`
since `getDefaultedFunctionKind` can't properly recognize these functions
as special members as part of `SetDeclDefaulted`.
Fixes PR45828 and PR44848
Differential Revision: https://reviews.llvm.org/D88327
This expands NRVO propagation for more cases:
Parse analysis improvement:
* Lambdas and Blocks with dependent return type can have their variables
marked as NRVO Candidates.
Variable instantiation improvements:
* Fixes crash when instantiating NRVO variables in Blocks.
* Functions, Lambdas, and Blocks which have auto return type have their
variables' NRVO status propagated. For Blocks with non-auto return type,
as a limitation, this propagation does not consider the actual return
type.
This also implements exclusion of VarDecls which are references to
dependent types.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: Quuxplusone
Differential Revision: https://reviews.llvm.org/D99696
A lambda in a function template may be recursively instantiated. The recursive
lambda will cause a lambda function instantiated multiple times, one inside another.
The inner LocalInstantiationScope should not be marked as MergeWithParentScope
since it already has references to locals properly substituted, otherwise it causes
assertion due to the check for duplicate locals in merged LocalInstantiationScope.
Reviewed by: Richard Smith
Differential Revision: https://reviews.llvm.org/D98068
This change caused build errors related to move-only __block variables,
see discussion on https://reviews.llvm.org/D99696
> This expands NRVO propagation for more cases:
>
> Parse analysis improvement:
> * Lambdas and Blocks with dependent return type can have their variables
> marked as NRVO Candidates.
>
> Variable instantiation improvements:
> * Fixes crash when instantiating NRVO variables in Blocks.
> * Functions, Lambdas, and Blocks which have auto return type have their
> variables' NRVO status propagated. For Blocks with non-auto return type,
> as a limitation, this propagation does not consider the actual return
> type.
>
> This also implements exclusion of VarDecls which are references to
> dependent types.
>
> Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
>
> Reviewed By: Quuxplusone
>
> Differential Revision: https://reviews.llvm.org/D99696
This also reverts the follow-on change which was hard to tease apart
form the one above:
> "[clang] Implement P2266 Simpler implicit move"
>
> This Implements [[http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2266r1.html|P2266 Simpler implicit move]].
>
> Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
>
> Reviewed By: Quuxplusone
>
> Differential Revision: https://reviews.llvm.org/D99005
This reverts commits 1e50c3d785 and
bf20631782.
This expands NRVO propagation for more cases:
Parse analysis improvement:
* Lambdas and Blocks with dependent return type can have their variables
marked as NRVO Candidates.
Variable instantiation improvements:
* Fixes crash when instantiating NRVO variables in Blocks.
* Functions, Lambdas, and Blocks which have auto return type have their
variables' NRVO status propagated. For Blocks with non-auto return type,
as a limitation, this propagation does not consider the actual return
type.
This also implements exclusion of VarDecls which are references to
dependent types.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: Quuxplusone
Differential Revision: https://reviews.llvm.org/D99696
This expands NRVO propagation for more cases:
Parse analysis improvement:
* Lambdas and Blocks with dependent return type can have their variables
marked as NRVO Candidates.
Variable instantiation improvements:
* Fixes crash when instantiating NRVO variables in Blocks.
* Functions, Lambdas, and Blocks which have auto return type have their
variables' NRVO status propagated. For Blocks with non-auto return type,
as a limitation, this propagation does not consider the actual return
type.
This also implements exclusion of VarDecls which are references to
dependent types.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: Quuxplusone
Differential Revision: https://reviews.llvm.org/D99696
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
This implements the 'using enum maybe-qualified-enum-tag ;' part of
1099. It introduces a new 'UsingEnumDecl', subclassed from
'BaseUsingDecl'. Much of the diff is the boilerplate needed to get the
new class set up.
There is one case where we accept ill-formed, but I believe this is
merely an extended case of an existing bug, so consider it
orthogonal. AFAICT in class-scope the c++20 rule is that no 2 using
decls can bring in the same target decl ([namespace.udecl]/8). But we
already accept:
struct A { enum { a }; };
struct B : A { using A::a; };
struct C : B { using A::a;
using B::a; }; // same enumerator
this patch permits mixtures of 'using enum Bob;' and 'using Bob::member;' in the same way.
Differential Revision: https://reviews.llvm.org/D102241
This adds support for p1099's 'using SCOPED_ENUM::MEMBER;'
functionality, bringing a member of an enumerator into the current
scope. The novel feature here, is that there need not be a class
hierarchical relationship between the current scope and the scope of
the SCOPED_ENUM. That's a new thing, the closest equivalent is a
typedef or alias declaration. But this means that
Sema::CheckUsingDeclQualifier needs adjustment. (a) one can't call it
until one knows the set of decls that are being referenced -- if
exactly one is an enumerator, we're in the new territory. Thus it
needs calling later in some cases. Also (b) there are two ways we hold
the set of such decls. During parsing (or instantiating a dependent
scope) we have a lookup result, and during instantiation we have a set
of shadow decls. Thus two optional arguments, at most one of which
should be non-null.
Differential Revision: https://reviews.llvm.org/D100276
This attribute applies to a using declaration, and permits importing a
declaration without knowing if that declaration exists. This is useful
for libc++ C wrapper headers that re-export declarations in std::, in
cases where the base C library doesn't provide all declarations.
This attribute was proposed in http://lists.llvm.org/pipermail/cfe-dev/2020-June/066038.html.
rdar://69313357
Differential Revision: https://reviews.llvm.org/D90188
Recently we added diagnosing ODR-use of host variables
in device functions, which includes ODR-use of const
host variables since they are not really emitted on
device side. This caused regressions since we used
to allow ODR-use of const host variables in device
functions.
This patch allows ODR-use of const variables in device
functions if the const variables can be statically initialized
and have an empty dtor. Such variables are marked with
implicit constant attrs and emitted on device side. This is
in line with what clang does for constexpr variables.
Reviewed by: Artem Belevich
Differential Revision: https://reviews.llvm.org/D103108
The original version of this was reverted, and @rjmcall provided some
advice to architect a new solution. This is that solution.
This implements a builtin to provide a unique name that is stable across
compilations of this TU for the purposes of implementing the library
component of the unnamed kernel feature of SYCL. It does this by
running the Itanium mangler with a few modifications.
Because it is somewhat common to wrap non-kernel-related lambdas in
macros that aren't present on the device (such as for logging), this
uniquely generates an ID for all lambdas involved in the naming of a
kernel. It uses the lambda-mangling number to do this, except replaces
this with its own number (starting at 10000 for readabililty reasons)
for lambdas used to name a kernel.
Additionally, this implements itself as constexpr with a slight catch:
if a name would be invalidated by the use of this lambda in a later
kernel invocation, it is diagnosed as an error (see the Sema tests).
Differential Revision: https://reviews.llvm.org/D103112
Erich Keane