127 Commits

Author SHA1 Message Date
Matheus Izvekov
91cdd35008
[clang] Improve nested name specifier AST representation (#147835)
This is a major change on how we represent nested name qualifications in
the AST.

* The nested name specifier itself and how it's stored is changed. The
prefixes for types are handled within the type hierarchy, which makes
canonicalization for them super cheap, no memory allocation required.
Also translating a type into nested name specifier form becomes a no-op.
An identifier is stored as a DependentNameType. The nested name
specifier gains a lightweight handle class, to be used instead of
passing around pointers, which is similar to what is implemented for
TemplateName. There is still one free bit available, and this handle can
be used within a PointerUnion and PointerIntPair, which should keep
bit-packing aficionados happy.
* The ElaboratedType node is removed, all type nodes in which it could
previously apply to can now store the elaborated keyword and name
qualifier, tail allocating when present.
* TagTypes can now point to the exact declaration found when producing
these, as opposed to the previous situation of there only existing one
TagType per entity. This increases the amount of type sugar retained,
and can have several applications, for example in tracking module
ownership, and other tools which care about source file origins, such as
IWYU. These TagTypes are lazily allocated, in order to limit the
increase in AST size.

This patch offers a great performance benefit.

It greatly improves compilation time for
[stdexec](https://github.com/NVIDIA/stdexec). For one datapoint, for
`test_on2.cpp` in that project, which is the slowest compiling test,
this patch improves `-c` compilation time by about 7.2%, with the
`-fsyntax-only` improvement being at ~12%.

This has great results on compile-time-tracker as well:

![image](https://github.com/user-attachments/assets/700dce98-2cab-4aa8-97d1-b038c0bee831)

This patch also further enables other optimziations in the future, and
will reduce the performance impact of template specialization resugaring
when that lands.

It has some other miscelaneous drive-by fixes.

About the review: Yes the patch is huge, sorry about that. Part of the
reason is that I started by the nested name specifier part, before the
ElaboratedType part, but that had a huge performance downside, as
ElaboratedType is a big performance hog. I didn't have the steam to go
back and change the patch after the fact.

There is also a lot of internal API changes, and it made sense to remove
ElaboratedType in one go, versus removing it from one type at a time, as
that would present much more churn to the users. Also, the nested name
specifier having a different API avoids missing changes related to how
prefixes work now, which could make existing code compile but not work.

How to review: The important changes are all in
`clang/include/clang/AST` and `clang/lib/AST`, with also important
changes in `clang/lib/Sema/TreeTransform.h`.

The rest and bulk of the changes are mostly consequences of the changes
in API.

PS: TagType::getDecl is renamed to `getOriginalDecl` in this patch, just
for easier to rebasing. I plan to rename it back after this lands.

Fixes #136624
Fixes https://github.com/llvm/llvm-project/issues/43179
Fixes https://github.com/llvm/llvm-project/issues/68670
Fixes https://github.com/llvm/llvm-project/issues/92757
2025-08-09 05:06:53 -03:00
YexuanXiao
7c402b8b81
Reland [Clang] Make the SizeType, SignedSizeType and PtrdiffType be named sugar types (#149613)
The checks for the 'z' and 't' format specifiers added in the original
PR #143653 had some issues and were overly strict, causing some build
failures and were consequently reverted at
4c85bf2fe8.

In the latest commit
27c58629ec,
I relaxed the checks for the 'z' and 't' format specifiers, so warnings
are now only issued when they are used with mismatched types.

The original intent of these checks was to diagnose code that assumes
the underlying type of `size_t` is `unsigned` or `unsigned long`, for
example:

```c
printf("%zu", 1ul); // Not portable, but not an error when size_t is unsigned long
```  

However, it produced a significant number of false positives. This was
partly because Clang does not treat the `typedef` `size_t` and
`__size_t` as having a common "sugar" type, and partly because a large
amount of existing code either assumes `unsigned` (or `unsigned long`)
is `size_t`, or they define the equivalent of size_t in their own way
(such as
sanitizer_internal_defs.h).2e67dcfdcd/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h (L203)
2025-07-19 03:44:14 -03:00
Kazu Hirata
4c85bf2fe8 Revert "[Clang] Make the SizeType, SignedSizeType and PtrdiffType be named sugar types instead of built-in types (#143653)"
This reverts commit c27e283cfbca2bd22f34592430e98ee76ed60ad8.

A builbot failure has been reported:
https://lab.llvm.org/buildbot/#/builders/186/builds/10819/steps/10/logs/stdio

I'm also getting a large number of warnings related to %zu and %zx.
2025-07-17 21:04:01 -07:00
YexuanXiao
c27e283cfb
[Clang] Make the SizeType, SignedSizeType and PtrdiffType be named sugar types instead of built-in types (#143653)
Including the results of `sizeof`, `sizeof...`, `__datasizeof`,
`__alignof`, `_Alignof`, `alignof`, `_Countof`, `size_t` literals, and
signed `size_t` literals, the results of pointer-pointer subtraction and
checks for standard library functions (and their calls).

The goal is to enable clang and downstream tools such as clangd and
clang-tidy to provide more portable hints and diagnostics.

The previous discussion can be found at #136542.

This PR implements this feature by introducing a new subtype of `Type`
called `PredefinedSugarType`, which was considered appropriate in
discussions. I tried to keep `PredefinedSugarType` simple enough yet not
limited to `size_t` and `ptrdiff_t` so that it can be used for other
purposes. `PredefinedSugarType` wraps a canonical `Type` and provides a
name, conceptually similar to a compiler internal `TypedefType` but
without depending on a `TypedefDecl` or a source file.

Additionally, checks for the `z` and `t` format specifiers in format
strings for `scanf` and `printf` were added. It will precisely match
expressions using `typedef`s or built-in expressions.

The affected tests indicates that it works very well.

Several code require that `SizeType` is canonical, so I kept `SizeType`
to its canonical form.

The failed tests in CI are allowed to fail. See the
[comment](https://github.com/llvm/llvm-project/pull/135386#issuecomment-3049426611)
in another PR #135386.
2025-07-17 22:45:57 -03:00
Matheus Izvekov
14f7bd63b9
Reland: [clang] preserve class type sugar when taking pointer to member (#132401)
Original PR: #130537
Originally reverted due to revert of dependent commit. Relanding with no
changes.

This changes the MemberPointerType representation to use a
NestedNameSpecifier instead of a Type to represent the base class.

Since the qualifiers are always parsed as nested names, there was an
impedance mismatch when converting these back and forth into types, and
this led to issues in preserving sugar.

The nested names are indeed a better match for these, as the differences
which a QualType can represent cannot be expressed syntatically, and
they represent the use case more exactly, being either dependent or
referring to a CXXRecord, unqualified.

This patch also makes the MemberPointerType able to represent sugar for
a {up/downcast}cast conversion of the base class, although for now the
underlying type is canonical, as preserving the sugar up to that point
requires further work.

As usual, includes a few drive-by fixes in order to make use of the
improvements.
2025-03-21 13:20:52 -03:00
Matheus Izvekov
5151e6d7fe
Revert "Reland: [clang] preserve class type sugar when taking pointer to member" (#132280)
Reverts llvm/llvm-project#132234

Needs to be reverted due to dependency.

This blocks reverting another PR, see here:
https://github.com/llvm/llvm-project/pull/131965#issuecomment-2741619498
2025-03-20 17:52:48 -03:00
Matheus Izvekov
578f38cd08
Reland: [clang] preserve class type sugar when taking pointer to member (#132234)
Original PR: #130537
Reland after updating lldb too.

This changes the MemberPointerType representation to use a
NestedNameSpecifier instead of a Type to represent the base class.

Since the qualifiers are always parsed as nested names, there was an
impedance mismatch when converting these back and forth into types, and
this led to issues in preserving sugar.

The nested names are indeed a better match for these, as the differences
which a QualType can represent cannot be expressed syntatically, and
they represent the use case more exactly, being either dependent or
referring to a CXXRecord, unqualified.

This patch also makes the MemberPointerType able to represent sugar for
a {up/downcast}cast conversion of the base class, although for now the
underlying type is canonical, as preserving the sugar up to that point
requires further work.

As usual, includes a few drive-by fixes in order to make use of the
improvements.
2025-03-20 15:33:54 -03:00
Matheus Izvekov
6cd62ad08c
Revert "[clang] improve class type sugar preservation in pointers to members" (#132215)
Reverts llvm/llvm-project#130537

This missed updating lldb, which we didn't notice due to lack of
pre-commit CI.
2025-03-20 11:09:25 -03:00
Matheus Izvekov
9b1f905b48
[clang] improve class type sugar preservation in pointers to members (#130537)
This changes the MemberPointerType representation to use a
NestedNameSpecifier instead of a Type to represent the class.

Since the qualifiers are always parsed as nested names, there was an
impedance mismatch when converting these back and forth into types, and
this led to issues in preserving sugar.

The nested names are indeed a better match for these, as the differences
which a QualType can represent cannot be expressed syntactically, and it
also represents the use case more exactly, being either dependent or
referring to a CXXRecord, unqualified.

This patch also makes the MemberPointerType able to represent sugar for
a {up/downcast}cast conversion of the base class, although for now the
underlying type is canonical, as preserving the sugar up to that point
requires further work.

As usual, includes a few drive-by fixes in order to make use of the
improvements, and removing some duplications, for example
CheckBaseClassAccess is deduplicated from across SemaAccess and
SemaCast.
2025-03-20 10:30:24 -03:00
Nathan Ridge
73adf26d50
[clangd] Handle DeducedTemplateSpecializationType in HeuristicResolver (#119107)
Fixes https://github.com/clangd/clangd/issues/2227
2024-12-09 12:59:01 -05:00
Pengcheng Wang
130e93cc26
Reland "[clang] Enable sized deallocation by default in C++14 onwards" (#90373)
Since C++14 has been released for about nine years and most standard
libraries have implemented sized deallocation functions, it's time to
make this feature default again.

This is another try of https://reviews.llvm.org/D112921.

The original commit cf5a8b4 was reverted by 2e5035a due to some
failures (see #83774).

Fixes #60061
2024-05-22 12:37:27 +08:00
Krystian Stasiowski
d4cf20ca37
[Clang][Sema] Don't set instantiated from function when rewriting operator<=> (#91339)
The following snippet causes a crash:
```
template<typename T>
struct A 
{
    bool operator<=>(const A&) const requires true = default;
};

bool f(A<int> a) 
{
    return a != A<int>();
}
```
This occurs because during the rewrite from `operator<=>` to
`operator==`, the "pattern" `operator<=>` function is set as the
instantiated from function for the newly created `operator==` function.
This is obviously incorrect, and this patch fixes it.
2024-05-07 20:09:19 -04:00
Krystian Stasiowski
8009bbec59
Reapply "[Clang][Sema] Diagnose class member access expressions naming non-existent members of the current instantiation prior to instantiation in the absence of dependent base classes (#84050)" (#90152)
Reapplies #84050, addressing a bug which cases a crash when an
expression with the type of the current instantiation is used as the
_postfix-expression_ in a class member access expression (arrow form).
2024-04-30 14:25:09 -04:00
Vitaly Buka
2e5035aeed
Revert "[clang] Enable sized deallocation by default in C++14 onwards (#83774)" (#90299)
https://lab.llvm.org/buildbot/#/builders/168/builds/20063 (should be
fixed with #90292)

More details in #83774

This reverts commit cf5a8b489464d09dfdd7a48ce7c8b41d3c9bf819.
2024-04-26 17:14:43 -07:00
Pengcheng Wang
cf5a8b4894
[clang] Enable sized deallocation by default in C++14 onwards (#83774)
Since C++14 has been released for about nine years and most standard
libraries have implemented sized deallocation functions, it's time to
make this feature default again.

This is another try of https://reviews.llvm.org/D112921.

Fixes #60061
2024-04-26 16:59:12 +08:00
Pranav Kant
0c6e1ca1c7 Revert "[Clang][Sema] Diagnose class member access expressions naming non-existent members of the current instantiation prior to instantiation in the absence of dependent base classes (#84050)"
This reverts commit a8fd0d029dca7d17eee72d0445223c2fe1ee7758.
2024-04-26 00:18:08 +00:00
Krystian Stasiowski
a8fd0d029d
[Clang][Sema] Diagnose class member access expressions naming non-existent members of the current instantiation prior to instantiation in the absence of dependent base classes (#84050)
Consider the following:
```cpp
template<typename T>
struct A
{
    auto f()
    {
        return this->x;
    }
};
```
Although `A` has no dependent base classes and the lookup context for
`x` is the current instantiation, we currently do not diagnose the
absence of a member `x` until `A<T>::f` is instantiated. This patch
moves the point of diagnosis for such expressions to occur at the point
of definition (i.e. prior to instantiation).
2024-04-25 14:50:53 -04:00
zibi2
180cf4daec
[clangd] Fix unittests in TargetDeclTest bucket (#89630)
This PR fixes the build errors for one of the `clangd` unit tests bucket
similar to the following:

```
.../clang-tools-extra/clangd/unittests/FindTargetTests.cpp:430:29: error: passing no argument for the '...' parameter of a variadic macro is a C++20 extension [-Werror,-Wc++20-extensions]
  430 |   EXPECT_DECLS("AutoTypeLoc");
      |                             ^
.../clang-tools-extra/clangd/unittests/FindTargetTests.cpp:98:9: note: macro 'EXPECT_DECLS' defined here
   98 | #define EXPECT_DECLS(NodeType, ...)                                            \
      |         ^
```

This happens when using a build compiler with #84520. The fix is to
include commas to compensate for empty vararg macro arguments in a few
instances.
2024-04-22 13:24:47 -04:00
Nathan Ridge
e6e53ca847
[clangd] [HeuristicResolver] Protect against infinite recursion on DependentNameTypes (#83542)
When resolving names inside templates that implement recursive
compile-time functions (e.g. waldo<N>::type is defined in terms
of waldo<N-1>::type), HeuristicResolver could get into an infinite
recursion, specifically one where resolveDependentNameType() can
be called recursively with the same DependentNameType*.

To guard against this, HeuristicResolver tracks, for each external
call into a HeuristicResolver function, the set of DependentNameTypes
that it has seen, and bails if it sees the same DependentNameType again.

To implement this, a helper class HeuristicResolverImpl is introduced
to store state that persists for the duration of an external call into
HeuristicResolver (but does not persist between such calls).

Fixes https://github.com/clangd/clangd/issues/1951
2024-03-04 00:12:56 -05:00
Younan Zhang
e81c981fe3
[clangd] Don't collect templated decls for builtin templates (#78466)
Builtin templates e.g. `__make_integer_seq`, `__type_pack_element` are
such that they don't have alias *Decls*.
[D133262](https://reviews.llvm.org/D133262) marked these as alias
templates, resulting in an attempt to collect their null "using" Decls
within our `TargetFinder`.

This fixes https://github.com/clangd/clangd/issues/1906.
2024-01-19 10:54:47 +08:00
Sam McCall
a8c9b9f140 [clangd] Support ConceptReference in generic AST wrangling code
Now we can store it in DynTypedNode, we can target these nodes
(SelectionTree) and resolve them (FindTarget).
This makes Hover, go-to-def etc work in all(?) cases.

Also support it in DumpAST.

Differential Revision: https://reviews.llvm.org/D159299
2023-09-04 14:58:25 +02:00
Aaron Ballman
a02f9a7756 Revert "[clang] Enable sized deallocation by default in C++14 onwards"
This reverts commit 2916b125f686115deab2ba573dcaff3847566ab9.

Reverting due to failures on:
https://lab.llvm.org/buildbot/#/builders/216/builds/26407
https://lab.llvm.org/staging/#/builders/247/builds/5659
http://45.33.8.238/win/83485/step_7.txt
2023-08-29 09:36:59 -04:00
wangpc
2916b125f6 [clang] Enable sized deallocation by default in C++14 onwards
Since C++14 has been released for about nine years and most standard
libraries have implemented sized deallocation functions, it's time to
make this feature default again.

Reviewed By: rnk, aaron.ballman, #libc, ldionne, Mordante, MaskRay

Differential Revision: https://reviews.llvm.org/D112921
2023-08-29 15:42:50 +08:00
Haojian Wu
8aa88ee5e0 [clangd] Fix the flaky FindTarget unittest after 1b66840
after 1b66840, FindTarget will report multiple refs with the same
location, make the sort order of the refs deterministic in
FindTargetTests.
2023-06-27 09:48:41 +02:00
David Goldman
1b66840f71 [clangd][ObjC] Support ObjC class rename from implementation decls
Reviewed By: kadircet

Differential Revision: https://reviews.llvm.org/D152720
2023-06-26 14:43:37 -04:00
Jens Massberg
6f065bfd63 [clangd][c++20]Consider rewritten binary operators in TargetFinder
In C++20 some binary operations can be rewritten, e.g. `a != b`
can be rewritten to `!(a == b)` if `!=` is not explicitly defined.
The `TargetFinder` hasn't considered the corresponding `CXXRewrittenBinaryOperator` yet. This resulted that the definition of such operators couldn't be found
when navigating to such a `!=` operator, see https://github.com/clangd/clangd/issues/1476.

In this patch we add support of `CXXRewrittenBinaryOperator` in `FindTarget`.
In such a case we redirect to the inner binary operator of the decomposed form.
E.g. in case that `a != b` has been rewritten to `!(a == b)` we go to the
`==` operator. The `==` operator might be implicitly defined (e.g. by a `<=>`
operator), but this case is already handled, see the new test.

I'm not sure if I the hover test which is added in this patch is the right one,
but at least is passed with this patch and fails without it :)

Note, that it might be a bit missleading that hovering over a `!=` refers to
"instance method operator==".

Differential Revision: https://reviews.llvm.org/D153331
2023-06-26 11:26:10 +02:00
Nathan Ridge
6fe9cfe413 [clangd] Use resolveTypeToRecordDecl() to resolve the type of a base specifier during heuristic resolution
The code for resolving the type of a base specifier was inside
CXXRecordDecl::lookupDependentName(), so this patch reimplements
lookupDependentName() in HeuristicResolver.

Fixes https://github.com/clangd/clangd/issues/1657

Differential Revision: https://reviews.llvm.org/D153248
2023-06-20 13:40:26 -04:00
Nathan Ridge
7a709689bc [clangd] Handle DependentNameType in HeuristicResolver::resolveTypeToRecordDecl()
Fixes https://github.com/clangd/clangd/issues/1671

Differential Revision: https://reviews.llvm.org/D152645
2023-06-16 15:19:50 -04:00
Nathan Ridge
19c9af81b1 [clangd] Unwrap type sugar in HeuristicResolver::resolveTypeToRecordDecl()
Fixes https://github.com/clangd/clangd/issues/1663

Differential Revision: https://reviews.llvm.org/D152500
2023-06-14 13:51:00 -04:00
Chuanqi Xu
55900a0d20 Recommit [Coroutines] Stop supportting std::experimental::coroutine_traits
As we discussed before, we should stop supporting
std::experimental::coroutine_traits in clang17. Now the clang16 is
branched so we can clean them now.

All the removed tests have been duplicated before.
2023-02-20 10:27:02 +08:00
Jordan Rupprecht
3432f4bf86 [test] Split out Annotations from TestingSupport
The Annotations helper class does not have a gtest or gmock dependency, but because it's bundled with the rest of TestingSupport, it gets one. By splitting it out, a target can use it without being forced to use LLVM's copy of gtest.

Reviewed By: GMNGeoffrey, sammccall, gribozavr2

Differential Revision: https://reviews.llvm.org/D141175
2023-01-12 13:40:47 -08:00
Aaron Ballman
19e984ef8f Properly print unnamed TagDecl objects in diagnostics
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
2022-10-14 08:18:28 -04:00
Sam McCall
2eaf6f973c [AST] Preserve more structure in UsingEnumDecl node.
- store NestedNameSpecifier & Loc for the qualifiers
  This information was entirely missing from the AST.
- expose the location information for qualifier/identifier/typedefs as typeloc
  This allows many traversals/astmatchers etc to handle these generically along
  with other references. The decl vs type split can help preserve typedef
  sugar when https://github.com/llvm/llvm-project/issues/57659 is resolved.
- fix the SourceRange of UsingEnumDecl to include 'using'.

Fixes https://github.com/clangd/clangd/issues/1283

Differential Revision: https://reviews.llvm.org/D134303
2022-10-12 19:54:51 +02:00
Sam McCall
2bb34cc462 [clangd] FindTarget: UsingEnumDecl is not an alias
Unlike UsingDecl it doesn't name the UsingShadowDecls it emits, so it doesn't
make sense to consider them the same thing. Don't consider the UsingEnumDecl
a target when the UsingShadowDecl is referenced.

Differential Revision: https://reviews.llvm.org/D135506
2022-10-08 19:29:35 +02:00
Matheus Izvekov
15f3cd6bfc
[clang] Implement ElaboratedType sugaring for types written bare
Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.

The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.

An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.

---

Troubleshooting list to deal with any breakage seen with this patch:

1) The most likely effect one would see by this patch is a change in how
   a type is printed. The type printer will, by design and default,
   print types as written. There are customization options there, but
   not that many, and they mainly apply to how to print a type that we
   somehow failed to track how it was written. This patch fixes a
   problem where we failed to distinguish between a type
   that was written without any elaborated-type qualifiers,
   such as a 'struct'/'class' tags and name spacifiers such as 'std::',
   and one that has been stripped of any 'metadata' that identifies such,
   the so called canonical types.
   Example:
   ```
   namespace foo {
     struct A {};
     A a;
   };
   ```
   If one were to print the type of `foo::a`, prior to this patch, this
   would result in `foo::A`. This is how the type printer would have,
   by default, printed the canonical type of A as well.
   As soon as you add any name qualifiers to A, the type printer would
   suddenly start accurately printing the type as written. This patch
   will make it print it accurately even when written without
   qualifiers, so we will just print `A` for the initial example, as
   the user did not really write that `foo::` namespace qualifier.

2) This patch could expose a bug in some AST matcher. Matching types
   is harder to get right when there is sugar involved. For example,
   if you want to match a type against being a pointer to some type A,
   then you have to account for getting a type that is sugar for a
   pointer to A, or being a pointer to sugar to A, or both! Usually
   you would get the second part wrong, and this would work for a
   very simple test where you don't use any name qualifiers, but
   you would discover is broken when you do. The usual fix is to
   either use the matcher which strips sugar, which is annoying
   to use as for example if you match an N level pointer, you have
   to put N+1 such matchers in there, beginning to end and between
   all those levels. But in a lot of cases, if the property you want
   to match is present in the canonical type, it's easier and faster
   to just match on that... This goes with what is said in 1), if
   you want to match against the name of a type, and you want
   the name string to be something stable, perhaps matching on
   the name of the canonical type is the better choice.

3) This patch could expose a bug in how you get the source range of some
   TypeLoc. For some reason, a lot of code is using getLocalSourceRange(),
   which only looks at the given TypeLoc node. This patch introduces a new,
   and more common TypeLoc node which contains no source locations on itself.
   This is not an inovation here, and some other, more rare TypeLoc nodes could
   also have this property, but if you use getLocalSourceRange on them, it's not
   going to return any valid locations, because it doesn't have any. The right fix
   here is to always use getSourceRange() or getBeginLoc/getEndLoc which will dive
   into the inner TypeLoc to get the source range if it doesn't find it on the
   top level one. You can use getLocalSourceRange if you are really into
   micro-optimizations and you have some outside knowledge that the TypeLocs you are
   dealing with will always include some source location.

4) Exposed a bug somewhere in the use of the normal clang type class API, where you
   have some type, you want to see if that type is some particular kind, you try a
   `dyn_cast` such as `dyn_cast<TypedefType>` and that fails because now you have an
   ElaboratedType which has a TypeDefType inside of it, which is what you wanted to match.
   Again, like 2), this would usually have been tested poorly with some simple tests with
   no qualifications, and would have been broken had there been any other kind of type sugar,
   be it an ElaboratedType or a TemplateSpecializationType or a SubstTemplateParmType.
   The usual fix here is to use `getAs` instead of `dyn_cast`, which will look deeper
   into the type. Or use `getAsAdjusted` when dealing with TypeLocs.
   For some reason the API is inconsistent there and on TypeLocs getAs behaves like a dyn_cast.

5) It could be a bug in this patch perhaps.

Let me know if you need any help!

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Differential Revision: https://reviews.llvm.org/D112374
2022-07-27 11:10:54 +02:00
Jonas Devlieghere
888673b6e3
Revert "[clang] Implement ElaboratedType sugaring for types written bare"
This reverts commit 7c51f02effdbd0d5e12bfd26f9c3b2ab5687c93f because it
stills breaks the LLDB tests. This was  re-landed without addressing the
issue or even agreement on how to address the issue. More details and
discussion in https://reviews.llvm.org/D112374.
2022-07-14 21:17:48 -07:00
Matheus Izvekov
7c51f02eff
[clang] Implement ElaboratedType sugaring for types written bare
Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.

The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.

An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.

---

Troubleshooting list to deal with any breakage seen with this patch:

1) The most likely effect one would see by this patch is a change in how
   a type is printed. The type printer will, by design and default,
   print types as written. There are customization options there, but
   not that many, and they mainly apply to how to print a type that we
   somehow failed to track how it was written. This patch fixes a
   problem where we failed to distinguish between a type
   that was written without any elaborated-type qualifiers,
   such as a 'struct'/'class' tags and name spacifiers such as 'std::',
   and one that has been stripped of any 'metadata' that identifies such,
   the so called canonical types.
   Example:
   ```
   namespace foo {
     struct A {};
     A a;
   };
   ```
   If one were to print the type of `foo::a`, prior to this patch, this
   would result in `foo::A`. This is how the type printer would have,
   by default, printed the canonical type of A as well.
   As soon as you add any name qualifiers to A, the type printer would
   suddenly start accurately printing the type as written. This patch
   will make it print it accurately even when written without
   qualifiers, so we will just print `A` for the initial example, as
   the user did not really write that `foo::` namespace qualifier.

2) This patch could expose a bug in some AST matcher. Matching types
   is harder to get right when there is sugar involved. For example,
   if you want to match a type against being a pointer to some type A,
   then you have to account for getting a type that is sugar for a
   pointer to A, or being a pointer to sugar to A, or both! Usually
   you would get the second part wrong, and this would work for a
   very simple test where you don't use any name qualifiers, but
   you would discover is broken when you do. The usual fix is to
   either use the matcher which strips sugar, which is annoying
   to use as for example if you match an N level pointer, you have
   to put N+1 such matchers in there, beginning to end and between
   all those levels. But in a lot of cases, if the property you want
   to match is present in the canonical type, it's easier and faster
   to just match on that... This goes with what is said in 1), if
   you want to match against the name of a type, and you want
   the name string to be something stable, perhaps matching on
   the name of the canonical type is the better choice.

3) This patch could exposed a bug in how you get the source range of some
   TypeLoc. For some reason, a lot of code is using getLocalSourceRange(),
   which only looks at the given TypeLoc node. This patch introduces a new,
   and more common TypeLoc node which contains no source locations on itself.
   This is not an inovation here, and some other, more rare TypeLoc nodes could
   also have this property, but if you use getLocalSourceRange on them, it's not
   going to return any valid locations, because it doesn't have any. The right fix
   here is to always use getSourceRange() or getBeginLoc/getEndLoc which will dive
   into the inner TypeLoc to get the source range if it doesn't find it on the
   top level one. You can use getLocalSourceRange if you are really into
   micro-optimizations and you have some outside knowledge that the TypeLocs you are
   dealing with will always include some source location.

4) Exposed a bug somewhere in the use of the normal clang type class API, where you
   have some type, you want to see if that type is some particular kind, you try a
   `dyn_cast` such as `dyn_cast<TypedefType>` and that fails because now you have an
   ElaboratedType which has a TypeDefType inside of it, which is what you wanted to match.
   Again, like 2), this would usually have been tested poorly with some simple tests with
   no qualifications, and would have been broken had there been any other kind of type sugar,
   be it an ElaboratedType or a TemplateSpecializationType or a SubstTemplateParmType.
   The usual fix here is to use `getAs` instead of `dyn_cast`, which will look deeper
   into the type. Or use `getAsAdjusted` when dealing with TypeLocs.
   For some reason the API is inconsistent there and on TypeLocs getAs behaves like a dyn_cast.

5) It could be a bug in this patch perhaps.

Let me know if you need any help!

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Differential Revision: https://reviews.llvm.org/D112374
2022-07-15 04:16:55 +02:00
Jonas Devlieghere
3968936b92
Revert "[clang] Implement ElaboratedType sugaring for types written bare"
This reverts commit bdc6974f92304f4ed542241b9b89ba58ba6b20aa because it
breaks all the LLDB tests that import the std module.

  import-std-module/array.TestArrayFromStdModule.py
  import-std-module/deque-basic.TestDequeFromStdModule.py
  import-std-module/deque-dbg-info-content.TestDbgInfoContentDequeFromStdModule.py
  import-std-module/forward_list.TestForwardListFromStdModule.py
  import-std-module/forward_list-dbg-info-content.TestDbgInfoContentForwardListFromStdModule.py
  import-std-module/list.TestListFromStdModule.py
  import-std-module/list-dbg-info-content.TestDbgInfoContentListFromStdModule.py
  import-std-module/queue.TestQueueFromStdModule.py
  import-std-module/stack.TestStackFromStdModule.py
  import-std-module/vector.TestVectorFromStdModule.py
  import-std-module/vector-bool.TestVectorBoolFromStdModule.py
  import-std-module/vector-dbg-info-content.TestDbgInfoContentVectorFromStdModule.py
  import-std-module/vector-of-vectors.TestVectorOfVectorsFromStdModule.py

https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/45301/
2022-07-13 09:20:30 -07:00
Matheus Izvekov
bdc6974f92
[clang] Implement ElaboratedType sugaring for types written bare
Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.

The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.

An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Differential Revision: https://reviews.llvm.org/D112374
2022-07-13 02:10:09 +02:00
Haojian Wu
5b0022a9df [clangd] Support UnresolvedUsingTypeLoc AST node in FindTarget.
to make features like hover, go-to-def work when the cursor is on the
UnresolvedUsingTypeLoc.

Differential Revision: https://reviews.llvm.org/D125684
2022-05-20 14:54:17 +02:00
Nathan Ridge
df2a4eae6b [clang] Expose CoawaitExpr's operand in the AST
Previously the Expr returned by getOperand() was actually the
subexpression common to the "ready", "suspend", and "resume"
expressions, which often isn't just the operand but e.g.
await_transform() called on the operand.

It's important for the AST to expose the operand as written
in the source for traversals and tools like clangd to work
correctly.

Fixes https://github.com/clangd/clangd/issues/939

Differential Revision: https://reviews.llvm.org/D115187
2022-05-17 08:13:37 -04:00
Haojian Wu
95f0f69441 [clangd] Handle the new Using TemplateName.
Add supports in FindTarget and IncludeCleaner. This would
improve AST-based features on a tempalte which is found via a using
declaration. For example, go-to-def on `vect^or<int> v;` gives us the
location of `using std::vector`, which was not previously.

Base on https://reviews.llvm.org/D123127

Differential Revision: https://reviews.llvm.org/D123212
2022-04-20 15:42:24 +02:00
David Goldman
54a962bbfe [clangd] Use ObjCProtocolLoc for generalized ObjC protocol support
This removes clangd's existing workaround in favor of proper support
via the newly added `ObjCProtocolLoc`. This improves support by
allowing clangd to properly identify which protocol is selected
now that `ObjCProtocolLoc` gets its own ASTNode.

Differential Revision: https://reviews.llvm.org/D119366
2022-02-18 15:24:00 -05:00
Kadir Cetinkaya
cae932b6c6
[clangd] Sort targets before printing for tests
Targets are not necessarily inserted in the order they appear in source
code. For example we could traverse overload sets, or selectively insert
template patterns after all other decls.
So order the targets before printing to make sure tests are not dependent on
such implementation details. We can also do it in production, but that might be
wasteful as we haven't seen any complaints in the wild around these orderings
yet.

Differential Revision: https://reviews.llvm.org/D117549
2022-01-19 14:06:53 +01:00
Adam Czachorowski
fba563e92b [clangd] TargetFinder: Fix assert-crash on TemplateExpansion args.
Previously we would call getAsTemplate() when kind == TemplateExpansion,
which triggers an assertion. The call is now replaced with
getAsTemplateOrTemplatePattern(), which is exactly the same as
getAsTemplate(), except it allows calls when kind == TemplateExpansion.

No change in behavior for no-assert builds.

Differential Revision: https://reviews.llvm.org/D111648
2021-10-13 13:15:36 +02:00
David Goldman
8401713b3e [clangd] Ignore ObjC id and instancetype in FindTarget
Even though they're implemented via typedefs, we typically
want to treat them like keywords.

We could add hover information / xrefs, but it's very unlikely
to provide any value.

Differential Revision: https://reviews.llvm.org/D108556
2021-09-14 09:53:42 -04:00
Richard Smith
5b8ddd2ccc Fix test following Clang change ef227b3. 2021-06-30 17:11:55 -07:00
David Goldman
13a8aa3ee1 [clang] RecursiveASTVisitor visits ObjCPropertyRefExpr's class receiver
We now make up a TypeLoc for the class receiver to simplify visiting,
notably for indexing, availability, and clangd.

Differential Revision: https://reviews.llvm.org/D101645
2021-06-01 14:45:25 -04:00
David Goldman
159dd447fe [clangd][ObjC] Highlight Objc Ivar refs
Treat them just like we do for properties - as a `property` semantic
token although ideally we could differentiate the two.

Differential Revision: https://reviews.llvm.org/D101785
2021-05-06 11:41:49 -04:00
David Goldman
39866d249a [clangd][ObjC] Improve support for class properties
Class properties are always implicit short-hands for the getter/setter
class methods.

We need to explicitly visit the interface decl `UIColor` in `UIColor.blueColor`,
otherwise we instead show the method decl even while hovering over
`UIColor` in the expression.

Differential Revision: https://reviews.llvm.org/D99975
2021-04-28 10:06:27 -04:00