This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
Implement https://cplusplus.github.io/CWG/issues/2631.html.
Immediate calls in default arguments and defaults members
are not evaluated.
Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.
The immediate calls are executed by doing a
transform on the initializing expression.
Note that lambdas are not considering subexpressions so
we do not need to transform them.
As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.
Reviewed By: aaron.ballman, #clang-language-wg
Differential Revision: https://reviews.llvm.org/D136554
Implement https://cplusplus.github.io/CWG/issues/2631.html.
Immediate calls in default arguments and defaults members
are not evaluated.
Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.
The immediate calls are executed by doing a
transform on the initializing expression.
Note that lambdas are not considering subexpressions so
we do not need to transform them.
As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.
Reviewed By: aaron.ballman, #clang-language-wg
Differential Revision: https://reviews.llvm.org/D136554
Implement https://cplusplus.github.io/CWG/issues/2631.html.
Immediate calls in default arguments and defaults members
are not evaluated.
Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.
The immediate calls are executed by doing a
transform on the initializing expression.
Note that lambdas are not considering subexpressions so
we do not need to transform them.
As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.
Reviewed By: aaron.ballman, #clang-language-wg
Differential Revision: https://reviews.llvm.org/D136554
template-template parameters. Although it effects whether a template can be
used as an argument for another template, the constraint seems not to
be checked, nor other major implementations (GCC, MSVC, et al.) check it.
Additionally, Part-A of the document seems to have been implemented.
So mark P0857R0 as completed.
Differential Revision: https://reviews.llvm.org/D134128
Implements the changes required to perform substitution with
non-canonical template arguments, and to 'finalize' them
by not placing 'Subst' nodes.
A finalized substitution means we won't resugar them later,
because these templates themselves were eagerly substituted
with the intended arguments at the point of use. We may still
resugar other templates used within those, though.
This patch does not actually implement any uses of this
functionality, those will be added in subsequent patches,
so expect no changes to existing tests.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D134604
Makes CheckTemplateArgumentList and the template deduction functions
produce a sugared converted argument list in addition to the canonical one.
This is mostly NFC except that we hook this up to a few diagnostics in
SemaOverload.
The infrastructure here will be used in subsequent patches
where we perform a finalized sugared substitution for entities
which we do not unique per specializations on canonical arguments,
and later on will be used for template specialization resugaring.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D133874
Implements the changes required to perform substitution with
non-canonical template arguments, and to 'finalize' them
by not placing 'Subst' nodes.
A finalized substitution means we won't resugar them later,
because these templates themselves were eagerly substituted
with the intended arguments at the point of use. We may still
resugar other templates used within those, though.
This patch does not actually implement any uses of this
functionality, those will be added in subsequent patches,
so expect no changes to existing tests.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D134604
Makes CheckTemplateArgumentList and the template deduction functions
produce a sugared converted argument list in addition to the canonical one.
This is mostly NFC except that we hook this up to a few diagnostics in
SemaOverload.
The infrastructure here will be used in subsequent patches
where we perform a finalized sugared substitution for entities
which we do not unique per specializations on canonical arguments,
and later on will be used for template specialization resugaring.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D133874
This reverts commit cecc9a92cf.
The problem ended up being how we were handling the lambda-context in
code generation: we were assuming any decl context here would be a
named-decl, but that isn't the case. Instead, we just replace it with
the concept's owning context.
Differential Revision: https://reviews.llvm.org/D136451
This reverts commit b876f6e2f2.
Still getting build failures on PPC AIX that aren't obvious what is causing
them, so reverting while I try to figure this out.
This reverts commit b7c922607c.
This seems to cause some problems with some modules related things,
which makes me think I should have updated the version-major in
ast-bit-codes? Going to revert to confirm this was a problem, then
change that and re-try a commit.
As that bug reports, the problem here is that the lambda's
'context-decl' was not set to the concept, and the lambda picked up
template arguments from the concept. SO, we failed to get the correct
template arguments in SemaTemplateInstantiate.
However, a Concept Specialization is NOT a decl, its an expression, so
we weren't able to put the concept in the decl tree like we needed.
This patch introduces a ConceptSpecializationDecl, which is the smallest
type possible to use for this purpose, containing only the template
arguments.
The net memory impliciation of this is turning a
trailing-objects into a pointer to a type with trailing-objects, so it
should be minor.
As future work, we may consider giving this type more responsibility, or
figuring out how to better merge duplicates, but as this is just a
template-argument collection at the moment, there isn't much value to
it.
Differential Revision: https://reviews.llvm.org/D136451
This is a change to how we represent type subsitution in the AST.
Instead of only storing the replaced type, we track the templated
entity we are substituting, plus an index.
We modify MLTAL to track the templated entity at each level.
Otherwise, it's much more expensive to go from the template parameter back
to the templated entity, and not possible to do in some cases, as when
we instantiate outer templates, parameters might still reference the
original entity.
This also allows us to very cheaply lookup the templated entity we saw in
the naming context and find the corresponding argument it was replaced
from, such as for implementing template specialization resugaring.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D131858
The diagnostics engine is very smart about being passed a NamedDecl to
print as part of a diagnostic; it gets the "right" form of the name,
quotes it properly, etc. However, the result of using an unnamed tag
declaration was to print '' instead of anything useful.
This patch causes us to print the same information we'd have gotten if
we had printed the type of the declaration rather than the name of it,
as that's the most relevant information we can display.
Differential Revision: https://reviews.llvm.org/D134813
requires-expression
As reported: https://github.com/llvm/llvm-project/issues/57487
We properly treated a failed instantiation of a concept as a
unsatisified constraint, however, we need to do this at the 'requires
clause' level as well. This ensures that the parameters on a requires
clause that fail instantiation will cause a satisfaction failure.
This patch implements this by running requires parameter clause
instantiation under a SFINAE trap, then stores any such failure as a
requirement failure, so it can be diagnosed later.
Previously, a lambda expression in a dependent context with a default argument
containing an immediately invoked lambda expression would produce a closure
class object that, if invoked such that the default argument was used, resulted
in a compiler crash or one of the following assertion failures during code
generation. The failures occurred regardless of whether the lambda expressions
were dependent.
clang/lib/CodeGen/CGCall.cpp:
Assertion `(isGenericMethod || Ty->isVariablyModifiedType() || Ty.getNonReferenceType()->isObjCRetainableType() || getContext() .getCanonicalType(Ty.getNonReferenceType()) .getTypePtr() == getContext().getCanonicalType((*Arg)->getType()).getTypePtr()) && "type mismatch in call argument!"' failed.
clang/lib/AST/Decl.cpp:
Assertion `!Init->isValueDependent()' failed.
Default arguments in declarations in local context are instantiated along with
their enclosing function or variable template (since such declarations can't
be explicitly specialized). Previously, such instantiations were performed at
the same time that their associated parameters were instantiated. However, that
approach fails in cases like the following in which the context for the inner
lambda is the outer lambda, but construction of the outer lambda is dependent
on the parameters of the inner lambda. This change resolves this dependency by
delyaing instantiation of default arguments in local contexts until after
construction of the enclosing context.
template <typename T>
auto f() {
return [](T = []{ return T{}; }()) { return 0; };
}
Refactoring included with this change results in the same code now being used
to instantiate default arguments that appear in local context and those that
are only instantiated when used at a call site; previously, such code was
duplicated and out of sync.
Fixes https://github.com/llvm/llvm-project/issues/49178
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D133500
As fallout of the Deferred Concept Instantiation patch (babdef27c5), we
got a number of reports of a regression, where we asserted when
instantiating a constraint on a generic lambda inside of a variable
template. See: https://github.com/llvm/llvm-project/issues/57958
The problem was that getTemplateInstantiationArgs function only walked
up declaration contexts, and missed that this is not necessarily the
case with a lambda (which can ALSO be in a separate context).
This patch refactors the getTemplateInstantiationArgs function in a way
that is hopefully more readable, and fixes the problem with the concepts
on a generic lambda.
Differential Revision: https://reviews.llvm.org/D134874
This reverts commit 95d94a6775.
This implements the deferred concepts instantiation, which should allow
the libstdc++ ranges to properly compile, and for the CRTP to work for
constrained functions.
Since the last attempt, this has fixed the issues from @wlei and
@mordante.
Differential Revision: https://reviews.llvm.org/D126907
This reverts commit d483730d8c.
This allegedly breaks a significant part of facebooks internal build.
Reverting while we wait for them to provide a reproducer of this from
@wlei.
This reverts commit 258c3aee54.
This should fix the libc++ issue that caused the revert, by re-designing
slightly how we determined when we should evaluate the constraints.
Additionally, many of the other components to the original patch (the
NFC parts) were committed separately to shrink the size of this patch
for review.
Differential Revision: https://reviews.llvm.org/D126907
Closing https://github.com/llvm/llvm-project/issues/56826.
The root cause for pr56826 is: when we collect the template args for the
friend, we need to judge if the friend lives in file context. However,
if the friend lives in ExportDecl lexically, the judgement here is
invalid.
The solution is easy. We should judge the non transparent context and
the ExportDecl is transparent context. So the solution should be good.
A main concern may be the patch doesn't handle all the places of the
same defect. I think it might not be bad since the patch itself should
be innocent.
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D131651
This reverts commit d4d47e574e.
This fixes the lldb crash that was observed by ensuring that our
friend-'template contains reference to' TreeTransform properly handles a
TemplateDecl.
This reverts commit 2f20743952 because it
triggers an assertion when building an LLDB test program:
Assertion failed: (InstantiatingSpecializations.empty() && "failed to
clean up an InstantiatingTemplate?"), function ~Sema, file
/Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/clang/lib/Sema/Sema.cpp,
line 458.
More details in https://reviews.llvm.org/D126907.
Fixes#54629.
The crash is is caused by the double template instantiation.
See the added test. Here is what happens:
- Template arguments for the partial specialization get instantiated.
- This causes instantitation into the corrensponding requires
expression.
- `TemplateInsantiator` correctly handles instantiation of parameters
inside `RequiresExprBody` and instantiates the constraint expression
inside the `NestedRequirement`.
- To build the substituted `NestedRequirement`, `TemplateInsantiator`
calls `Sema::BuildNestedRequirement` calls
`CheckConstraintSatisfaction`, which results in another template
instantiation (with empty template arguments). This seem to be an
implementation detail to handle constraint satisfaction and is not
required by the standard.
- The recursive template instantiation tries to find the parameter
inside `RequiresExprBody` and fails with the corresponding assertion.
Note that this only happens as both instantiations happen with the class
partial template specialization set as `Sema.CurContext`, which is
considered a dependent `DeclContext`.
To fix the assertion, avoid doing the recursive template instantiation
and instead evaluate resulting expressions in-place.
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D127487
This patch implements a necessary part of P0848, the overload resolution for destructors.
It is now possible to overload destructors based on constraints, and the eligible destructor
will be selected at the end of the class.
The approach this patch takes is to perform the overload resolution in Sema::ActOnFields
and to mark the selected destructor using a new property in FunctionDeclBitfields.
CXXRecordDecl::getDestructor is then modified to use this property to return the correct
destructor.
This closes https://github.com/llvm/llvm-project/issues/45614.
Reviewed By: #clang-language-wg, erichkeane
Differential Revision: https://reviews.llvm.org/D126194
This includes a fix for the libc++ issue I ran across with friend
declarations not properly being identified as overloads.
This reverts commit 45c07db31c.
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
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
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
Kazu Hirata