[Clang] [NFC] Mark `UnresolvedSetImpl`'s move operations as defaulted (#97930)

Revert "Reapply "[Clang] Implement resolution for CWG1835 (#92957)" (#98547)"

This reverts commit ce4aada6e2135e29839f672a6599db628b53295d and a
follow-up patch 8ef26f1289bf069ccc0d6383f2f4c0116a120

Revert "Reapply "[Clang] Implement resolution for CWG1835 (#92957)" (#98547)"

This reverts commit ce4aada6e2135e29839f672a6599db628b53295d and a
follow-up patch 8ef26f1289bf069ccc0d6383f2f4c0116a1206c1.

This new warning can not be fully suppressed by the
`-Wno-missing-dependent-template-keyword` flag, this gives developer no
time to do the cleanup in a large codebase, see https://github.com/llvm/llvm-project/pull/98547#issuecomment-2228250884

show more ...

Reapply "[Clang] Implement resolution for CWG1835 (#92957)" (#98547)

Reapplies #92957, fixing an instance where the `template` keyword was
missing prior to a dependent name in `llvm/ADT/ArrayRef.h`

Reapply "[Clang] Implement resolution for CWG1835 (#92957)" (#98547)

Reapplies #92957, fixing an instance where the `template` keyword was
missing prior to a dependent name in `llvm/ADT/ArrayRef.h`. An
_alias-declaration_ is used to work around a bug affecting GCC releases
before 11.1 (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94799) which
rejects the use of the `template` keyword prior to the
_nested-name-specifier_ in the class member access.

show more ...

Revert "[Clang] Implement resolution for CWG1835 (#92957)"

ppc64le-lld-multistage-test has been failing.

This reverts commit 7bfb98c34687d9784f36937c3ff3e735698b498a.

[Clang] Implement resolution for CWG1835 (#92957)

CWG1835 was one of the many core issues resolved by P1787R6: "Declarations and where to
find them" (http://wg21.link/p1787r6). Its resolution chang

[Clang] Implement resolution for CWG1835 (#92957)

CWG1835 was one of the many core issues resolved by P1787R6: "Declarations and where to
find them" (http://wg21.link/p1787r6). Its resolution changes how
member-qualified names (as defined by [basic.lookup.qual.general] p2) are looked
up. This patch implementation that resolution.

Previously, an _identifier_ following `.` or `->` would be first looked
up in the type of the object expression (i.e. qualified lookup), and
then in the context of the _postfix-expression_ (i.e. unqualified
lookup) if nothing was found; the result of the second lookup was
required to name a class template. Notably, this second lookup would
occur even when the object expression was dependent, and its result
would be used to determine whether a `<` token is the start of a
_template-argument_list_.

The new wording in [basic.lookup.qual.general] p2 states:
> A member-qualified name is the (unique) component name, if any, of
> - an _unqualified-id_ or
> - a _nested-name-specifier_ of the form _`type-name ::`_ or
_`namespace-name ::`​_
>
> in the id-expression of a class member access expression. A
***qualified name*** is
> - a member-qualified name or
> - the terminal name of
> - a _qualified-id_,
> - a _using-declarator_,
> - a _typename-specifier_,
> - a _qualified-namespace-specifier_, or
> - a _nested-name-specifier_, _elaborated-type-specifier_, or
_class-or-decltype_ that has a _nested-name-specifier_.
>
> The _lookup context_ of a member-qualified name is the type of its
associated object expression (considered dependent if the object
expression is type-dependent). The lookup context of any other qualified
name is the type, template, or namespace nominated by the preceding
_nested-name-specifier_.

And [basic.lookup.qual.general] p3 now states:
> _Qualified name lookup_ in a class, namespace, or enumeration performs
a search of the scope associated with it except as specified below.
Unless otherwise specified, a qualified name undergoes qualified name
lookup in its lookup context from the point where it appears unless the
lookup context either is dependent and is not the current instantiation
or is not a class or class template. If nothing is found by qualified
lookup for a member-qualified name that is the terminal name of a
_nested-name-specifier_ and is not dependent, it undergoes unqualified
lookup.

In non-standardese terms, these two paragraphs essentially state the
following:
- A name that immediately follows `.` or `->` in a class member access
expression is a member-qualified name
- A member-qualified name will be first looked up in the type of the
object expression `T` unless `T` is a dependent type that is _not_ the
current instantiation, e.g.
```
template<typename T>
struct A
{
void f(T* t)
{
this->x; // type of the object expression is 'A<T>'. although 'A<T>' is dependent, it is the
// current instantiation so we look up 'x' in the template definition context.

t->y; // type of the object expression is 'T' ('->' is transformed to '.' per [expr.ref]).
// 'T' is dependent and is *not* the current instantiation, so we lookup 'y' in the
// template instantiation context.
}
};
```
- If the first lookup finds nothing and:
- the member-qualified name is the first component of a
_nested-name-specifier_ (which could be an _identifier_ or a
_simple-template-id_), and either:
- the type of the object expression is the current instantiation and it
has no dependent base classes, or
- the type of the object expression is not dependent

then we lookup the name again, this time via unqualified lookup.

Although the second (unqualified) lookup is stated not to occur when the
member-qualified name is dependent, a dependent name will _not_ be
dependent once the template is instantiated, so the second lookup must
"occur" during instantiation if qualified lookup does not find anything.
This means that we must perform the second (unqualified) lookup during
parsing even when the type of the object expression is dependent, but
those results are _not_ used to determine whether a `<` token is the
start of a _template-argument_list_; they are stored so we can replicate
the second lookup during instantiation.

In even simpler terms (paraphrasing the meeting minutes from the review of P1787; see https://wiki.edg.com/bin/view/Wg21summer2020/P1787%28Lookup%29Review2020-06-15Through2020-06-18):
- Unqualified lookup always happens for the first name in a
_nested-name-specifier_ that follows `.` or `->`
- The result of that lookup is only used to determine whether `<` is the
start of a _template-argument-list_ if the first (qualified) lookup
found nothing and the lookup context:
- is not dependent, or
- is the current instantiation and has no dependent base classes.

An example:
```
struct A
{
void f();
};

template<typename T>
using B = A;

template<typename T>
struct C : A
{
template<typename U>
void g();

void h(T* t)
{
this->g<int>(); // ok, '<' is the start of a template-argument-list ('g' was found via qualified lookup in the current instantiation)
this->B<void>::f(); // ok, '<' is the start of a template-argument-list (current instantiation has no dependent bases, 'B' was found via unqualified lookup)
t->g<int>(); // error: '<' means less than (unqualified lookup does not occur for a member-qualified name that isn't the first component of a nested-name-specifier)
t->B<void>::f(); // error: '<' means less than (unqualified lookup does not occur if the name is dependent)
t->template B<void>::f(); // ok: '<' is the start of a template-argument-list ('template' keyword used)
}
};
```

Some additional notes:
- Per [basic.lookup.qual.general] p1, lookup for a
member-qualified name only considers namespaces, types, and templates
whose specializations are types if it's an _identifier_ followed by
`::`; lookup for the component name of a _simple-template-id_ followed
by `::` is _not_ subject to this rule.
- The wording which specifies when the second unqualified lookup occurs
appears to be paradoxical. We are supposed to do it only for the first
component name of a _nested-name-specifier_ that follows `.` or `->`
when qualified lookup finds nothing. However, when that name is followed
by `<` (potentially starting a _simple-template-id_) we don't _know_
whether it will be the start of a _nested-name-specifier_ until we do
the lookup -- but we aren't supposed to do the lookup until we know it's
part of a _nested-name-specifier_! ***However***, since we only do the
second lookup when the first lookup finds nothing (and the name isn't
dependent), ***and*** since neither lookup is type-only, the only valid
option is for the name to be the _template-name_ in a
_simple-template-id_ that is followed by `::` (it can't be an
_unqualified-id_ naming a member because we already determined that the
lookup context doesn't have a member with that name). Thus, we can lock
into the _nested-name-specifier_ interpretation and do the second lookup
without having to know whether the _simple-template-id_ will be followed
by `::` yet.

show more ...

[serialization] no transitive decl change (#92083)

Following of https://github.com/llvm/llvm-project/pull/86912

The motivation of the patch series is that, for a module interface unit
`X`, when the

[serialization] no transitive decl change (#92083)

Following of https://github.com/llvm/llvm-project/pull/86912

The motivation of the patch series is that, for a module interface unit
`X`, when the dependent modules of `X` changes, if the changes is not
relevant with `X`, we hope the BMI of `X` won't change. For the specific
patch, we hope if the changes was about irrelevant declaration changes,
we hope the BMI of `X` won't change. **However**, I found the patch
itself is not very useful in practice, since the adding or removing
declarations, will change the state of identifiers and types in most
cases.

That said, for the most simple example,

```
// partA.cppm
export module m:partA;

// partA.v1.cppm
export module m:partA;
export void a() {}

// partB.cppm
export module m:partB;
export void b() {}

// m.cppm
export module m;
export import :partA;
export import :partB;

// onlyUseB;
export module onlyUseB;
import m;
export inline void onluUseB() {
b();
}
```

the BMI of `onlyUseB` will change after we change the implementation of
`partA.cppm` to `partA.v1.cppm`. Since `partA.v1.cppm` introduces new
identifiers and types (the function prototype).

So in this patch, we have to write the tests as:

```
// partA.cppm
export module m:partA;
export int getA() { ... }
export int getA2(int) { ... }

// partA.v1.cppm
export module m:partA;
export int getA() { ... }
export int getA(int) { ... }
export int getA2(int) { ... }

// partB.cppm
export module m:partB;
export void b() {}

// m.cppm
export module m;
export import :partA;
export import :partB;

// onlyUseB;
export module onlyUseB;
import m;
export inline void onluUseB() {
b();
}
```

so that the new introduced declaration `int getA(int)` doesn't introduce
new identifiers and types, then the BMI of `onlyUseB` can keep
unchanged.

While it looks not so great, the patch should be the base of the patch
to erase the transitive change for identifiers and types since I don't
know how can we introduce new types and identifiers without introducing
new declarations. Given how tightly the relationship between
declarations, types and identifiers, I think we can only reach the ideal
state after we made the series for all of the three entties.

The design of the patch is similar to
https://github.com/llvm/llvm-project/pull/86912, which extends the
32-bit DeclID to 64-bit and use the higher bits to store the module file
index and the lower bits to store the Local Decl ID.

A slight difference is that we only use 48 bits to store the new DeclID
since we try to use the higher 16 bits to store the module ID in the
prefix of Decl class. Previously, we use 32 bits to store the module ID
and 32 bits to store the DeclID. I don't want to allocate additional
space so I tried to make the additional space the same as 64 bits. An
potential interesting thing here is about the relationship between the
module ID and the module file index. I feel we can get the module file
index by the module ID. But I didn't prove it or implement it. Since I
want to make the patch itself as small as possible. We can make it in
the future if we want.

Another change in the patch is the new concept Decl Index, which means
the index of the very big array `DeclsLoaded` in ASTReader. Previously,
the index of a loaded declaration is simply the Decl ID minus
PREDEFINED_DECL_NUMs. So there are some places they got used
ambiguously. But this patch tried to split these two concepts.

As https://github.com/llvm/llvm-project/pull/86912 did, the change will
increase the on-disk PCM file sizes. As the declaration ID may be the
most IDs in the PCM file, this can have the biggest impact on the size.
In my experiments, this change will bring 6.6% increase of the on-disk
PCM size. No compile-time performance regression observed. Given the
benefits in the motivation example, I think the cost is worthwhile.

show more ...

Revert "[serialization] no transitive decl change (#92083)"

This reverts commit 5c104879c1a98eeb845c03e7c45206bd48e88f0c.

The ArmV7 bot is complaining the change breaks the alignment.

[serialization] no transitive decl change (#92083)

Following of https://github.com/llvm/llvm-project/pull/86912

The motivation of the patch series is that, for a module interface unit
`X`, when the

[serialization] no transitive decl change (#92083)

Following of https://github.com/llvm/llvm-project/pull/86912

The motivation of the patch series is that, for a module interface unit
`X`, when the dependent modules of `X` changes, if the changes is not
relevant with `X`, we hope the BMI of `X` won't change. For the specific
patch, we hope if the changes was about irrelevant declaration changes,
we hope the BMI of `X` won't change. **However**, I found the patch
itself is not very useful in practice, since the adding or removing
declarations, will change the state of identifiers and types in most
cases.

That said, for the most simple example,

```
// partA.cppm
export module m:partA;

// partA.v1.cppm
export module m:partA;
export void a() {}

// partB.cppm
export module m:partB;
export void b() {}

// m.cppm
export module m;
export import :partA;
export import :partB;

// onlyUseB;
export module onlyUseB;
import m;
export inline void onluUseB() {
b();
}
```

the BMI of `onlyUseB` will change after we change the implementation of
`partA.cppm` to `partA.v1.cppm`. Since `partA.v1.cppm` introduces new
identifiers and types (the function prototype).

So in this patch, we have to write the tests as:

```
// partA.cppm
export module m:partA;
export int getA() { ... }
export int getA2(int) { ... }

// partA.v1.cppm
export module m:partA;
export int getA() { ... }
export int getA(int) { ... }
export int getA2(int) { ... }

// partB.cppm
export module m:partB;
export void b() {}

// m.cppm
export module m;
export import :partA;
export import :partB;

// onlyUseB;
export module onlyUseB;
import m;
export inline void onluUseB() {
b();
}
```

so that the new introduced declaration `int getA(int)` doesn't introduce
new identifiers and types, then the BMI of `onlyUseB` can keep
unchanged.

While it looks not so great, the patch should be the base of the patch
to erase the transitive change for identifiers and types since I don't
know how can we introduce new types and identifiers without introducing
new declarations. Given how tightly the relationship between
declarations, types and identifiers, I think we can only reach the ideal
state after we made the series for all of the three entties.

The design of the patch is similar to
https://github.com/llvm/llvm-project/pull/86912, which extends the
32-bit DeclID to 64-bit and use the higher bits to store the module file
index and the lower bits to store the Local Decl ID.

A slight difference is that we only use 48 bits to store the new DeclID
since we try to use the higher 16 bits to store the module ID in the
prefix of Decl class. Previously, we use 32 bits to store the module ID
and 32 bits to store the DeclID. I don't want to allocate additional
space so I tried to make the additional space the same as 64 bits. An
potential interesting thing here is about the relationship between the
module ID and the module file index. I feel we can get the module file
index by the module ID. But I didn't prove it or implement it. Since I
want to make the patch itself as small as possible. We can make it in
the future if we want.

Another change in the patch is the new concept Decl Index, which means
the index of the very big array `DeclsLoaded` in ASTReader. Previously,
the index of a loaded declaration is simply the Decl ID minus
PREDEFINED_DECL_NUMs. So there are some places they got used
ambiguously. But this patch tried to split these two concepts.

As https://github.com/llvm/llvm-project/pull/86912 did, the change will
increase the on-disk PCM file sizes. As the declaration ID may be the
most IDs in the PCM file, this can have the biggest impact on the size.
In my experiments, this change will bring 6.6% increase of the on-disk
PCM size. No compile-time performance regression observed. Given the
benefits in the motivation example, I think the cost is worthwhile.

show more ...

[AST] Fix bug in UnresolvedSet::erase of last element

UnresolvedSet::erase works by popping the last element then replacing
the element to be erased with that element. When the element to be
erased

[AST] Fix bug in UnresolvedSet::erase of last element

UnresolvedSet::erase works by popping the last element then replacing
the element to be erased with that element. When the element to be
erased is itself the last element this leads to writing past the end
of the set, causing an assertion failure.

Fix this by making erase of the last element just pop that element.

Differential Revision: https://reviews.llvm.org/D154502

show more ...

AST: Avoid using SmallVector::set_size() in UnresolvedSet

Update UnresolvedSet to use (and expose) `SmallVector::truncate()` instead
of `SmallVector::set_size()`. The latter is going to made private

AST: Avoid using SmallVector::set_size() in UnresolvedSet

Update UnresolvedSet to use (and expose) `SmallVector::truncate()` instead
of `SmallVector::set_size()`. The latter is going to made private in a
future commit to avoid misuse.

Differential Revision: https://reviews.llvm.org/D115386

show more ...

Add missed #include in llvmorg-10-init-11532-g848934c67d4.

[c++20] Fix handling of unqualified lookups from a defaulted comparison
function.

We need to perform unqualified lookups from the context of a defaulted
comparison, but not until we implicitly defin

[c++20] Fix handling of unqualified lookups from a defaulted comparison
function.

We need to perform unqualified lookups from the context of a defaulted
comparison, but not until we implicitly define the function, at which
point we can't do those lookups any more. So perform the lookup from the
end of the class containing the =default declaration and store the
lookup results on the defaulted function until we synthesize the body.

show more ...

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636

show more ...

Remove trailing space

sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338291

Remove \brief commands from doxygen comments.

This is similar to the LLVM change https://reviews.llvm.org/D46290.

We've been running doxygen with the autobrief option for a couple of
years now. Thi

Remove \brief commands from doxygen comments.

This is similar to the LLVM change https://reviews.llvm.org/D46290.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46320

llvm-svn: 331834

show more ...

[AST] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).

llvm-svn: 318813

Try to work around an MSVC 2013 bug around defaulted default ctors

An UnresolvedSetIterator() is supposed to be zeroed out, but MSVC 2013
does not do that.

llvm-svn: 278842

P0217R3: Perform semantic checks and initialization for the bindings in a
decomposition declaration for arrays, aggregate-like structs, tuple-like
types, and (as an extension) for complex and vector

P0217R3: Perform semantic checks and initialization for the bindings in a
decomposition declaration for arrays, aggregate-like structs, tuple-like
types, and (as an extension) for complex and vector types.

llvm-svn: 278435

show more ...

[NFC] Header cleanup

Summary: Removed unused headers, replaced some headers with forward class declarations

Patch by: Eugene <claprix@yandex.ru>

Differential Revision: https://reviews.llvm.org/D20

[NFC] Header cleanup

Summary: Removed unused headers, replaced some headers with forward class declarations

Patch by: Eugene <claprix@yandex.ru>

Differential Revision: https://reviews.llvm.org/D20100

llvm-svn: 275882

show more ...

Re-add (user defined) move ops to UnresolvedSetImpl to allow UnresolvedSet to be implicitly movable

llvm-svn: 263747

Remove defaulted move ops, the type is zero-cost copyable anyway, so there's no need for specific move ops

(addresses MSVC build error, since MSVC 2013 can't generate default move
ops)

llvm-svn: 26

Remove defaulted move ops, the type is zero-cost copyable anyway, so there's no need for specific move ops

(addresses MSVC build error, since MSVC 2013 can't generate default move
ops)

llvm-svn: 263732

show more ...

Fix implicit copy ctor and copy assignment operator warnings when -Wdeprecated passed.

Fix implicit copy ctor and copy assignment operator warnings
when -Wdeprecated passed.

Patch by Don Hinton!

D

Fix implicit copy ctor and copy assignment operator warnings when -Wdeprecated passed.

Fix implicit copy ctor and copy assignment operator warnings
when -Wdeprecated passed.

Patch by Don Hinton!

Differential Revision: http://reviews.llvm.org/D18123

llvm-svn: 263730

show more ...

Roll-back r250822.

Summary: It breaks the build for the ASTMatchers

Subscribers: klimek, cfe-commits

Differential Revision: http://reviews.llvm.org/D13893

llvm-svn: 250827

Apply modernize-use-default to clang.

Summary: Replace empty bodies of default constructors and destructors with '= default'.

Reviewers: bkramer, klimek

Subscribers: klimek, alexfh, cfe-commits

D

Apply modernize-use-default to clang.

Summary: Replace empty bodies of default constructors and destructors with '= default'.

Reviewers: bkramer, klimek

Subscribers: klimek, alexfh, cfe-commits

Differential Revision: http://reviews.llvm.org/D13890

llvm-svn: 250822

show more ...

Reimplement iterator wrappers on top of llvm::iterator_adaptor_base.

Eliminates a ton of boilerplate proxying the iterator methods. NFC.

llvm-svn: 227764