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
eccc734a69, 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 is the funcref counterpart to 890146b. We introduce a new attribute
that marks a function pointer as a funcref. It also implements builtin
__builtin_wasm_ref_null_func(), that returns a null funcref value.
Differential Revision: https://reviews.llvm.org/D128440
GH58452 is a regression in the 16.0 release branch caused by both:
b8a1b698af and
3a0309c536
This patch reverts both of those to make the 'valid' code stop
diagnosing
at the expense of crashes on invalid + unclear diagnostics.
This patch also adds the tests from GH58452 to prevent any
re-application from breaking this again.
Revert "[clang] Improve diagnostics for expansion length mismatch"
This reverts commit 3a0309c536.
Revert "[clang] fix missing initialization of original number of expansions"
This reverts commit b8a1b698af.
Differential Revision: https://reviews.llvm.org/D145605
This allows `static_assert(false)` to not be ill-formed
in template definitions.
This change is applied as a DR in all C++ modes.
Of notes, a couple of tests were relying of the eager nature
of static_assert
* test/SemaTemplate/instantiation-dependence.cpp
* test/SemaTemplate/instantiate-var-template.cpp
I don't know if the changes to `static_assert`
still allow that sort of tests to be expressed.
Reviewed By: #clang-language-wg, erichkeane, aaron.ballman
Differential Revision: https://reviews.llvm.org/D144285
This patch introduces a new type __externref_t that denotes a WebAssembly opaque
reference type. It also implements builtin __builtin_wasm_ref_null_extern(),
that returns a null value of __externref_t. This lays the ground work
for further builtins and reference types.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D122215
As reported in GH60642, we asserted when there was a lambda defined in a
template arguments inside of a concept, which caused us to not properly
set up the list of instantiation args. This patch ensures that the
'lambda context decl' correctly falls-through the template argument
instantiation, so that it is available when instantiating the lambda,
and thus, when setting up the lambda instantiation args list.
This patch introduces a new type __externref_t that denotes a WebAssembly opaque
reference type. It also implements builtin __builtin_wasm_ref_null_extern(),
that returns a null value of __externref_t. This lays the ground work
for further builtins and reference types.
Differential Revision: https://reviews.llvm.org/D122215
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.
It seems that the sugaring patches had some pretty significant
interdependencies, and at least one issue exists that requires part of
the concept-sugaring patch. I don't believe this to have anything to do
with the increased compile-times that were seen, so hopefully this will
fix our problems without further regressions.
See https://reviews.llvm.org/rG12cb1cb3720de8d164196010123ce1a8901d8122
for discussion.
Differential Revision: https://reviews.llvm.org/D142500
This reverts commit b8064374b2.
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.
This patch handles default integral non-type template parameters.
After this patch the clang TypePrinter will omit default integral
template arguments when the `PrintingPolicy::SuppressDefaultTemplateArgs`
option is specified and sets us up to be able to re-use
`clang::isSubstitutedDefaultArgument` from the DWARF CodeGen
component.
Differential Revision: https://reviews.llvm.org/D139986
More work for temp.friend p9, this fixes a previous bug where we didn't
properly consider a friend to depend on the enclosing template if it
only did so via an NTTP.
This revision fixes typos where there are 2 consecutive words which are
duplicated. There should be no code changes in this revision (only
changes to comments and docs). Do let me know if there are any
undesirable changes in this revision. Thanks.
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
As reported in https://github.com/llvm/llvm-project/issues/49192,
we did a pretty poor job diagnosing cases where someone forgot 'auto', a
nd is probably in the middle of a variable declaration. This patch
makes us properly diagnose in cases where the next token is a reference,
or CVR qualifier.
This makes use of the changes introduced in D134604, in order to
instantiate alias templates witn a final sugared substitution.
This comes at no additional relevant cost.
Since we don't track / unique them in specializations, we wouldn't be
able to resugar them later anyway.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D136565
This makes use of the changes introduced in D134604, in order to
instantiate non-type template parameters and default template arguments
with a final sugared substitution.
This comes at no additional relevant cost.
Since we don't track / unique them in specializations, we wouldn't be
able to resugar them later anyway.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D136564
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.
This patch reverts
- commit d4b1964f05
- commit 59f0827e2cf3755834620e7e0b6d946832440f80([clang] Instantiate alias templates with sugar)
As it makes clang fail to pass some code it used to compile.
See comments: https://reviews.llvm.org/D136564#3891065
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
Fixes: https://github.com/llvm/llvm-project/issues/50886
**Adding requires clause to template head** or **constraining the template parameter type** is ineffective because, even though it creates a non-equivalent template head [temp.over.link#6](https://eel.is/c++draft/temp.over.link#6) and hence eligible for overload resolution, `Derived::foo` still [hides any previous using decl](https://github.com/llvm/llvm-project/blob/main/clang/lib/Sema/SemaOverload.cpp#L1283-L1301,).
Clang diverges from gcc here and can be seen more clearly in this example:
```
struct base {
template <int N, int M>
int foo() { return 1; };
};
struct bar : public base {
using base::foo;
template <int N>
int foo() { return 2; };
};
int main() {
bar f;
f.foo<10, 10>(); // clang previously errored while GCC does not.
}
```
https://godbolt.org/z/v5hnh6czq. We see that `bar::foo` hides `base::foo` because it only differs in the head.
Adding a trailing `requires` to the definition was a nice find. In this case, clang considers them [overloads](https://github.com/llvm/llvm-project/blob/main/clang/lib/Sema/SemaOverload.cpp#L1148-L1152) because of [mismatching requires clause.](https://github.com/llvm/llvm-project/blob/main/clang/lib/Sema/SemaOverload.cpp#L1390-L1405). So both of them make it to the overload resolution (where constrained Derived::foo is rejected then).
---
In this patch, we do not ignore matching the template head (template parameters, type contraints and trailing requires) while considering whether the using decl of base member should be hidden. The return type of a templated function is still not considered as different return types would create ambiguous candidates.
The changed tests looks reasonable and also matches GCC behaviour: https://godbolt.org/z/8KqPEThrY
Note: We are now able to create an ambiguity in case where both base member and derived member specialisations satisfy the constraints (when the constraints are not same). Ideally using-decl should not create ambiguity. I plan to fix this later if it gathers more attention.
Reviewed By: ilya-biryukov, #clang-language-wg
Differential Revision: https://reviews.llvm.org/D136440
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
This makes use of the changes introduced in D134604, in order to
instantiate alias templates witn a final sugared substitution.
This comes at no additional relevant cost.
Since we don't track / unique them in specializations, we wouldn't be
able to resugar them later anyway.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D136565
This makes use of the changes introduced in D134604, in order to
instantiate non-type template parameters and default template arguments
with a final sugared substitution.
This comes at no additional relevant cost.
Since we don't track / unique them in specializations, we wouldn't be
able to resugar them later anyway.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D136564
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 these are much like template type aliases, where we don't
track a specialization for them and just substitute them eagerly,
we can't resugar them anyway, and there is no relevant cost in just
performing a finalizing sugared substitution.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D136563
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
We already did this for all the other kinds of non-type template
argument.
Note: Based on earlier reverted patch from zygoloid.
Differential Revision: https://reviews.llvm.org/D136803
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
This makes use of the changes introduced in D134604, in order to
instantiate alias templates witn a final sugared substitution.
This comes at no additional relevant cost.
Since we don't track / unique them in specializations, we wouldn't be
able to resugar them later anyway.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D136565
This makes use of the changes introduced in D134604, in order to
instantiate non-type template parameters and default template arguments
with a final sugared substitution.
This comes at no additional relevant cost.
Since we don't track / unique them in specializations, we wouldn't be
able to resugar them later anyway.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D136564
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 these are much like template type aliases, where we don't
track a specialization for them and just substitute them eagerly,
we can't resugar them anyway, and there is no relevant cost in just
performing a finalizing sugared substitution.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D136563
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.
