This change reverts the functional change from D144626 but retains its
test. Instead of dealing with the possibility that a trailing requires
clause might have been rewritten into some other incorrect form, just
stop rewriting it.
No functionality changes intended.
Reviewed By: erichkeane, ChuanqiXu
Differential Revision: https://reviews.llvm.org/D147281
Since P0857, part of C++20, a *lambda-expression* can contain a
*requires-clause* after its *template-parameter-list*.
While support for this was added as part of
eccc734a69c0c012ae3160887b65a535b35ead3e, one specific case isn't
handled properly, where the *requires-clause* consists of an
instantiation of a boolean variable template. This is due to a
diagnostic check which was written with the assumption that a
*requires-clause* can never be followed by a left parenthesis. This
assumption no longer holds for lambdas.
This diagnostic check would then attempt to perform a "recovery", but it
does so in a valid parse state, resulting in an invalid parse state
instead!
This patch adds a special case when parsing requires clauses of lambda
templates, to skip this diagnostic check.
Fixes https://github.com/llvm/llvm-project/issues/61278
Fixes https://github.com/llvm/llvm-project/issues/61387
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D146140
This implements P2036R3 and P2579R0.
That is, explicit, int, and implicit capture become visible
at the start of the parameter head.
Reviewed By: aaron.ballman, rupprecht, shafik
Differential Revision: https://reviews.llvm.org/D124351
This reverts commit d708a186b6a9b050d09558163dd353d9f738c82d (and typo fix e4bc9898ddbeb70bc49d713bbf863f050f21e03f). It causes a compilation error for this:
```
struct StringLiteral {
template <int N>
StringLiteral(const char (&array)[N])
__attribute__((enable_if(N > 0 && N == __builtin_strlen(array) + 1,
"invalid string literal")));
};
struct Message {
Message(StringLiteral);
};
void Func1() {
auto x = Message("x"); // Note: this is fine
// Note: "xx\0" to force a different type, StringLiteral<3>, otherwise this
// successfully builds.
auto y = [&](decltype(Message("xx"))) {};
// ^ fails with: repro.cc:18:13: error: reference to local variable 'array'
// declared in enclosing function 'StringLiteral::StringLiteral<3>'
(void)x;
(void)y;
}
```
More details posted to D124351.
This implements P2036R3 and P2579R0.
That is, explicit, int, and implicit capture become visible
at the start of the parameter head.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D124351
Fixes: #60323https://github.com/llvm/llvm-project/issues/60323
The problem is that we are profiling the 'Expr' components directly,
however when they contain an unresolved lookup, those canonicalize
identically. The result was the two versions of calls to 'go' were
canonicalized identically.
This patch fixes this by ensuring we consider the declaration the
constraint is attached to, when possible. When not, we skip the
diagnostic.
The result is that we are relaxing our diagnostic in some cases (Of
which I couldn't come up with a reproducer), such that we might see
overflows when evaluating constraints that depend on themselves in a way
that they are not attached to a declaration directly, such as if
they are nested requirements, though the hope is this won't be a
problem, since the 'parent' named constraint would catch this. I'm
hopeful that the 'worst case' is that we catch recursion 'later' in the
process, instead of immediately.
As came up in the discussion on
https://reviews.llvm.org/rG12cb1cb3720de8d164196010123ce1a8901d8122
We were asserting because the attempt to print a note found that our
source range for a immediately declared constraint (as a part of
Parameter Mapping Substitution) wasn't in order.
However, it doesn't really make sense to have the location of this be
the whole list of template arguments, as that would result in the range
being:
bool func(std::thing<char*> auto foo) {}
^^^^^^^^^^^^^^^
Even if done correctly. Instead, this patch makes the range be just
'foo' in this case (or a pointer right after 'auto' if unnamed).
This reverts commit b8064374b217db061213c561ec8f3376681ff9c8.
Based on the report here:
https://github.com/llvm/llvm-project/issues/59271
this produces a significant increase in memory use of the compiler and a
large compile-time regression. This patch reverts this so that we don't
branch for release with that issue.
> Dependent access checks.
Fixes: https://github.com/llvm/llvm-project/issues/53364
We previously ignored dependent access checks to private members.
These are visible only to the `RequiresExprBodyExpr` (through `PerformDependentDiagnositcs`) and not to the individual requirements.
---
> Non-dependent access checks.
Fixes: https://github.com/llvm/llvm-project/issues/53334
Access to members in a non-dependent context would always yield an
invalid expression. When it appears in a requires-expression, then this
is a hard error as this would always result in a substitution failure.
https://eel.is/c++draft/expr.prim.req#general-note-1
> Note 1: If a requires-expression contains invalid types or expressions in its requirements, and it does not appear within the declaration of a templated entity, then the program is ill-formed. — end note]
> If the substitution of template arguments into a requirement would always result in a substitution failure, the program is ill-formed; no diagnostic required.
The main issue here is the delaying of the diagnostics.
Use a `ParsingDeclRAIIObject` creates a separate diagnostic pool for diagnositcs associated to the `RequiresExprBodyDecl`.
This is important because dependent diagnostics should not be leaked/delayed to higher scopes (Eg. inside a template function or in a trailing requires). These dependent diagnostics must be attached to the `DeclContext` of the parameters of `RequiresExpr` (which is the `RequiresExprBodyDecl` in this case).
Non dependent diagnostics, on the other hand, should not delayed and surfaced as hard errors.
Differential Revision: https://reviews.llvm.org/D140547
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
Based on discussion on the core reflector, it was made clear that a
concept that depends on itself should be a hard error, not a constraint
failure. This patch implements a stack of constraint-checks-in-progress
to make sure we quit, rather than hitting stack-exhaustion.
Note that we DO need to be careful to make sure we still check
constraints properly that are caused by a previous constraint, but not
derived from (such as when a check causes us to check special member
function generation), so we cannot use the existing logic to see if this
is being instantiated.
This fixes https://github.com/llvm/llvm-project/issues/44304 and
https://github.com/llvm/llvm-project/issues/50891.
Differential Revision: https://reviews.llvm.org/D136975
concept
When we failed the lookup of the function, we tried to form a
RecoveryExpr that caused us to recursively re-check the same constraint,
which caused us to try to double-insert the satisfaction into the cache.
This patch makes us just return the inner-cached version instead. We DO
end up double-evaluating thanks to the recovery-expr, but there isn't a
good way around that.
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
Since we don't unique specializations for concepts, we can just instantiate
them with the sugared template arguments, at negligible cost.
If we don't track their specializations, we can't resugar them later
anyway, and that would be more expensive than just instantiating them
sugared in the first place since it would require an additional pass.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D136566
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
Since we don't unique specializations for concepts, we can just instantiate
them with the sugared template arguments, at negligible cost.
If we don't track their specializations, we can't resugar them later
anyway, and that would be more expensive than just instantiating them
sugared in the first place since it would require an additional pass.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D136566
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
This reverts commit cecc9a92cfca71c1b6c2a35c5e302ab649496d11.
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 b876f6e2f28779211a829d7d4e841fe68885ae20.
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 b7c922607c5ba93db8b893d4ba461052af8317b5.
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
`|| fold` is not disjunction; `&& fold` is not conjunction. Both are atomic per
current wording. See http://cplusplus.github.io/concepts-ts/ts-active.html#28.
D128750 accidentally tried to partially addresss this which is not desirable.
This patch reverts that part and associated test cases.
For some reason the initial deferred concepts patch didn't add this
check, which someone noticed could cause a problem with other patches
applied. This makes sure we check these, so that an error condition
cannot cause us to crash.
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
As another regression from the Deferred Concepts Instantiation patch, we
weren't properly detecting that a friend referenced its containing
Record when it referred to it without its template parameters. This
patch makes sure that we do.
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
As reported in GH #57945, this would crash because the decl context for
the lambda was being loaded via 'getNonClosureContext', which only gets
CODE contexts, so a global lambda was getting 'nullptr' here instead.
This patch does some work to make sure we get a valid/valuable
declcontext here instead.
This reverts commit 192d69f7e65a625e344421841e731e39f80595f5.
This fixes the condition to check whether this is a situation where we
are in a recovery-expr'ed concept a little better, so we don't access an
inactive member of a union, which should make the bots happy.
Differential Revision: https://reviews.llvm.org/D134542
This reverts commit e3d14bee238b672a7a112311eefee55e142eaefc.
There are apparently a large number of crashes in libcxx and some JSON
Parser thing, so clearly this has some sort of serious issue. Reverting
so I can take some time to figure out what is going on.
Discovered by reducing a different problem, we currently assert because
we failed to make the constraint expressions not dependent, since a
RecoveryExpr cannot be transformed.
This patch fixes that, and gets reasonably nice diagnostics by
introducing a concept (hah!) of "ContainsErrors" to the Satisfaction
types, which causes us to treat the candidate as non-viable.
However, just making THAT candidate non-viable would result in choosing
the 'next best' canddiate, which can result in awkward errors, where we
start evaluating a candidate that is not intended to be selected.
Because of this, and to make diagnostics more relevant, we now just
cause the entire lookup to result in a 'no-viable-candidates'.
This means we will only emit the list of candidates, rather than any
cascading failures.
This reverts commit 95d94a67755620c0a2871ac6f056ca8e9731d5e9.
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 d483730d8c3fa2e0d4192b2f3c61c761b124e6ad.
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 258c3aee54e11bc5c5d8ac137eb15e8d5bbcc7e4.
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
In preperation of the deferred instantation progress, this patch
propagates the multi-level template argument lists further through the
API to reduce the size of that patch.
This reverts commit befa8cf087dbb8159a4d9dc8fa4d6748d6d5049a.
Apparently this breaks some libc++ builds with an apparent assertion,
so I'm looking into that .
This reverts commit d4d47e574ecae562ab32f8ac7fa3f4d424bb6574.
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 2f207439521d62d9551b2884158368e8b34084e5 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.
