Commit graph

129 commits

Author SHA1 Message Date
Jakob Linke
bcc5d96ccc
[clangd] Resolve __builtin_offsetof designator components precisely (#194407)
Building on the new TraverseOffsetOfNode hook in RecursiveASTVisitor and
the OffsetOfNode DynTypedNode kind, teach SelectionTree, FindTarget, and
the explicit-references collector to address each designator component
individually. Cursor positions inside a nested designator (for example
the 'B' in __builtin_offsetof(A, B.c)) now resolve to the corresponding
field instead of always picking the innermost component.

- SelectionTree: wrap each OffsetOfNode visit in traverseNode so it
  becomes a selectable node alongside its enclosing OffsetOfExpr.
- FindTarget::allTargetDecls: resolve OffsetOfNode (Field kind) to its
  FieldDecl, and drop the OffsetOfExpr fallback so non-component
  selections do not guess a field target.
- ExplicitReferenceCollector: emit one ReferenceLoc per component via a
  new VisitOffsetOfNode hook, replacing the manual component loop in
  refInStmt.

Tests:
- TargetDeclTest.OffsetOf: precise resolution for outer/inner/base/
  identifier components, macro form, array index expressions, and
  non-component selections.
- Hover.All and Hover.OffsetOfBuiltin: field cases for nested offsetof,
  and expression hover on the builtin token.
- LocateSymbol.All: simple, outer, inner, macro, inherited-field, and
  builtin-token cases.
- AllRefsInFoo: existing offsetof cases continue to pass via the new
  per-component VisitOffsetOfNode path.

Context: 
https://github.com/llvm/llvm-project/pull/194122
https://github.com/llvm/llvm-project/pull/192953
2026-04-29 07:39:19 +03:00
Jakob Linke
cfa67454e9
[clangd] Add go-to-definition support for fields in offsetof expressions (#192953)
clangd had no handling for OffsetOfExpr in FindTarget.cpp, so
go-to-definition and find-references on field names inside
__builtin_offsetof(Type, field) produced no results.

Fix this by adding VisitOffsetOfExpr to both visitors:
- The TargetFinder visitor in add(const Stmt*) so that allTargetDecls()
resolves the referenced FieldDecl(s).
- The refInStmt visitor so that findExplicitReferences() emits a
ReferenceLoc per field component, enabling find-references and rename to
locate each field at its source position.

Each OffsetOfNode of kind Field is visited; Identifier nodes (unresolved
dependent-type designators) and Base nodes (implicit base-class
indirections) are intentionally skipped.

Repro:
```                                                                                                                                                                                                                                             
  struct Foo { int bar; };                               
  int x = offsetof(Foo, bar);  // go-to-def on `bar` previously did nothing
```
2026-04-22 09:14:53 +03:00
Nathan Ridge
9062cf5039
[clangd] Report reference to UsingType's target decl at the correct location (#186310)
Fixes https://github.com/clangd/clangd/issues/2617
2026-03-16 06:28:51 +00:00
Kazu Hirata
a2263812ed
[clang-tools-extra] Replace LLVM_ATTRIBUTE_UNUSED with [[maybe_unused]] (NFC) (#163915)
This patch replaces LLVM_ATTRIBUTE_UNUSED with [[maybe_unused]],
introduced as part of C++17.
2025-10-17 07:27:19 -07:00
Matheus Izvekov
b516dcc998
[clang] NFC: rename TagType::getOriginalDecl back to getDecl (#163271)
This rename was made as part of
https://github.com/llvm/llvm-project/pull/147835 in order to ease
rebasing the PR, and give a nice window for other patches to get rebased
as well.

It has been a while already, so lets go ahead and rename it back.
2025-10-15 16:11:17 -03:00
Matheus Izvekov
07e4907319
[clangd] NFC: FindTarget code cleanup post #163206 2025-10-14 11:05:33 -03:00
Matheus Izvekov
7a11eb96d5
[clang] NFC: NNS getLocalSourceRange user cleanup (#163206)
This adds a note to the documentation of getLocalSourceRange, and cleans
up one of the users of this function which was changed in
https://github.com/llvm/llvm-project/pull/147835

This also removes `TypeLoc::getNonPrefixBeginLoc`, which was recently
introduced in the above patch, as that became unused.
2025-10-13 13:16:25 -03:00
Matheus Izvekov
ba9d1c41c4
[clang] AST: remove DependentTemplateSpecializationType (#158109)
A DependentTemplateSpecializationType (DTST) is basically just a
TemplateSpecializationType (TST) with a hardcoded DependentTemplateName
(DTN) as its TemplateName.

This removes the DTST and replaces all uses of it with a TST, removing a
lot of duplication in the implementation.

Technically the hardcoded DTN is an optimization for a most common case,
but the TST implementation is in better shape overall and with other
optimizations, so this patch ends up being an overall performance
positive:
<img width="1465" height="38" alt="image"
src="https://github.com/user-attachments/assets/084b0694-2839-427a-b664-eff400f780b5"
/>

A DTST also didn't allow a template name representing a DTN that was
substituted, such as from an alias template, while the TST does allow it
by the simple fact it can hold an arbitrary TemplateName, so this patch
also increases the amount of sugar retained, while still being faster
overall.

Example (from included test case):
```C++
template<template<class> class TT> using T1 = TT<int>;
template<class T> using T2 = T1<T::template X>;
```

Here we can now represent in the AST that `TT` was substituted for the
dependent template name `T::template X`.
2025-09-12 13:55:38 -03:00
Matheus Izvekov
249167a898
[clang] NFC: reintroduce clang/include/clang/AST/Type.h (#155050)
This reintroduces `Type.h`, having earlier been renamed to `TypeBase.h`,
as a redirection to `TypeBase.h`, and redirects most users to include
the former instead.

This is a preparatory patch for being able to provide inline definitions
for `Type` methods which would otherwise cause a circular dependency
with `Decl{,CXX}.h`.

Doing these operations into their own NFC patch helps the git rename
detection logic work, preserving the history.

This patch makes clang just a little slower to build (~0.17%), just
because it makes more code indirectly include `DeclCXX.h`.
2025-08-27 13:11:34 -03:00
Matheus Izvekov
bcd1530836
[clang] NFC: rename clang/include/clang/AST/Type.h to TypeBase.h (#155049)
This is a preparatory patch, to be able to provide inline definitions
for `Type` functions which depend on `Decl{,CXX}.h`. As the latter also
depends on `Type.h`, this would not be possible without some
reorganizing.

Splitting this rename into its own patch allows git to track this as a
rename, and preserve all git history, and not force any code
reformatting.

A later NFC patch will reintroduce `Type.h` as redirection to
`TypeBase.h`, rewriting most places back to directly including `Type.h`
instead of `TypeBase.h`, leaving only a handful of places where this is
necessary.

Then yet a later patch will exploit this by making more stuff inline.
2025-08-27 13:09:48 -03:00
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
Yanzuo Liu
4a9eaad9e1
[Clang][AST][NFC] Introduce NamespaceBaseDecl (#149123)
Add `NamespaceBaseDecl` as common base class of `NamespaceDecl` and
`NamespaceAliasDecl`. This simplifies `NestedNameSpecifier` a bit.

Co-authored-by: Matheus Izvekov <mizvekov@gmail.com>
2025-07-18 09:01:47 +08:00
Kazu Hirata
ab1fea49e2
[clang-tools-extra] Use llvm::replace (NFC) (#140200) 2025-05-16 07:30:46 -07:00
Matheus Izvekov
dc17429ae6
[clang] improved preservation of template keyword (#133610) 2025-04-01 17:15:18 -03:00
Nathan Ridge
4740e09703
[clang][Sema] Respect qualification of methods in heuristic results (#123551)
Fixes https://github.com/llvm/llvm-project/issues/123549
2025-01-21 03:54:42 -05:00
Nathan Ridge
ae932becb2
[clang][Sema] Upstream HeuristicResolver from clangd (#121314)
Fixes https://github.com/llvm/llvm-project/issues/121310
2025-01-17 17:01:00 -05:00
Andrey Ali Khan Bolshakov
5518a9d767
[c++20] P1907R1: Support for generalized non-type template arguments of scalar type. (#78041)
Previously committed as 9e08e51a20, and
reverted because a dependency commit was reverted, then committed again
as 4b574008ae and reverted again because
"dependency commit" 5a391d38ac was
reverted. But it doesn't seem that 5a391d38ac was a real dependency
for this.

This commit incorporates 4b574008ae and
18e093faf7 by Richard Smith (@zygoloid),
with some minor fixes, most notably:

- `UncommonValue` renamed to `StructuralValue`

- `VK_PRValue` instead of `VK_RValue` as default kind in lvalue and
member pointer handling branch in
`BuildExpressionFromNonTypeTemplateArgumentValue`;

- handling of `StructuralValue` in `IsTypeDeclaredInsideVisitor`;

- filling in `SugaredConverted` along with `CanonicalConverted`
parameter in `Sema::CheckTemplateArgument`;

- minor cleanup in
`TemplateInstantiator::transformNonTypeTemplateParmRef`;

- `TemplateArgument` constructors refactored;

- `ODRHash` calculation for `UncommonValue`;

- USR generation for `UncommonValue`;

- more correct MS compatibility mangling algorithm (tested on MSVC ver.
19.35; toolset ver. 143);

- IR emitting fixed on using a subobject as a template argument when the
corresponding template parameter is used in an lvalue context;

- `noundef` attribute and opaque pointers in `template-arguments` test;

- analysis for C++17 mode is turned off for templates in
`warn-bool-conversion` test; in C++17 and C++20 mode, array reference
used as a template argument of pointer type produces template argument
of UncommonValue type, and
`BuildExpressionFromNonTypeTemplateArgumentValue` makes
`OpaqueValueExpr` for it, and `DiagnoseAlwaysNonNullPointer` cannot see
through it; despite of "These cases should not warn" comment, I'm not
sure about correct behavior; I'd expect a suggestion to replace `if` by
`if constexpr`;

- `temp.arg.nontype/p1.cpp` and `dr18xx.cpp` tests fixed.
2024-01-21 21:28:57 +01:00
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
Kazu Hirata
f9306f6de3
[ADT] Rename llvm::erase_value to llvm::erase (NFC) (#70156)
C++20 comes with std::erase to erase a value from std::vector.  This
patch renames llvm::erase_value to llvm::erase for consistency with
C++20.

We could make llvm::erase more similar to std::erase by having it
return the number of elements removed, but I'm not doing that for now
because nobody seems to care about that in our code base.

Since there are only 50 occurrences of erase_value in our code base,
this patch replaces all of them with llvm::erase and deprecates
llvm::erase_value.
2023-10-24 23:03:13 -07:00
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
Jens Massberg
c39dcd2c2b [c++20][clangd] Simplify code using the new ConceptReference nodes.
Directly traverse `ConceptReference`s in FindTarget.cpp.

There is no need for the extra logic for `AutoTypeLoc`s in SemanticHightlighting.cpp as the concept information is stored in a `ConceptReference` which is now traversed.

Differential Revision: https://reviews.llvm.org/D159268
2023-08-31 13:53:56 +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
Bill Wendling
b51a03e1bb [Clang][NFC] Rename methods/vars to reflect their real usage
The "getField" method is a bit confusing considering we also have a
"getFieldName" method. Instead, use "getFieldDecl" rather than
"getField".

Differential Revision: https://reviews.llvm.org/D147743
2023-04-18 13:48:08 -07:00
Bill Wendling
554ba99695 Revert "[Clang] Refactor "Designators" into a unified implementation [NFC]"
This reverts commit 3c07db5f58.

This caused https://github.com/llvm/llvm-project/issues/61118. Reverting
to ensure this is a pure NFC change.
2023-03-02 12:09:29 -08:00
Bill Wendling
3c07db5f58 [Clang] Refactor "Designators" into a unified implementation [NFC]
The interfaces for designators (i.e. C99 designated initializers) was
done in two slightly different ways. This was rather wasteful as the
differences could be combined into one.

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D140584
2023-02-07 12:59:17 -08:00
Nathan Ridge
6c46913914 [clangd] Semantic highlighting for constrained-parameter
Differential Revision: https://reviews.llvm.org/D142871
2023-02-06 03:44:36 -05:00
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
Sam McCall
283b6dec8d [clangd] Make go-to-type work on member function calls 2022-09-26 04:18:43 +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 7c51f02eff 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 bdc6974f92 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
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
Sam McCall
4d006520b8 [clangd] Clean up unused includes. NFCI
Add includes where needed to fix build.
Haven't systematically added used headers, so there is still accidental
dependency on transitive includes.
2022-02-26 12:00:16 +01:00
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
Sam McCall
af27466c50 Reland "[AST] Add UsingType: a sugar type for types found via UsingDecl"
This reverts commit cc56c66f27.
Fixed a bad assertion, the target of a UsingShadowDecl must not have
*local* qualifiers, but it can be a typedef whose underlying type is qualified.
2021-12-20 18:03:15 +01:00
Sam McCall
cc56c66f27 Revert "[AST] Add UsingType: a sugar type for types found via UsingDecl"
This reverts commit e1600db19d.

Breaks sanitizer tests, at least on windows:
https://lab.llvm.org/buildbot/#/builders/127/builds/21592/steps/4/logs/stdio
2021-12-20 17:53:56 +01:00
Sam McCall
e1600db19d [AST] Add UsingType: a sugar type for types found via UsingDecl
Currently there's no way to find the UsingDecl that a typeloc found its
underlying type through. Compare to DeclRefExpr::getFoundDecl().

Design decisions:
- a sugar type, as there are many contexts this type of use may appear in
- UsingType is a leaf like TypedefType, the underlying type has no TypeLoc
- not unified with UnresolvedUsingType: a single name is appealing,
  but being sometimes-sugar is often fiddly.
- not unified with TypedefType: the UsingShadowDecl is not a TypedefNameDecl or
  even a TypeDecl, and users think of these differently.
- does not cover other rarer aliases like objc @compatibility_alias,
  in order to be have a concrete API that's easy to understand.
- implicitly desugared by the hasDeclaration ASTMatcher, to avoid
  breaking existing patterns and following the precedent of ElaboratedType.

Scope:
- This does not cover types associated with template names introduced by
  using declarations. A future patch should introduce a sugar TemplateName
  variant for this. (CTAD deduced types fall under this)
- There are enough AST matchers to fix the in-tree clang-tidy tests and
  probably any other matchers, though more may be useful later.

Caveats:
- This changes a fairly common pattern in the AST people may depend on matching.
  Previously, typeLoc(loc(recordType())) matched whether a struct was
  referred to by its original scope or introduced via using-decl.
  Now, the using-decl case is not matched, and needs a separate matcher.
  This is similar to the case of typedefs but nevertheless both adds
  complexity and breaks existing code.

Differential Revision: https://reviews.llvm.org/D114251
2021-12-20 17:15:38 +01:00
Matheus Izvekov
c9e46219f3
[clang] retain type sugar in auto / template argument deduction
This implements the following changes:
* AutoType retains sugared deduced-as-type.
* Template argument deduction machinery analyses the sugared type all the way
down. It would previously lose the sugar on first recursion.
* Undeduced AutoType will be properly canonicalized, including the constraint
template arguments.
* Remove the decltype node created from the decltype(auto) deduction.

As a result, we start seeing sugared types in a lot more test cases,
including some which showed very unfriendly `type-parameter-*-*` types.

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

Reviewed By: rsmith, #libc, ldionne

Differential Revision: https://reviews.llvm.org/D110216
2021-11-15 23:07:45 +01:00
Matheus Izvekov
6438a52df1
Revert "[clang] retain type sugar in auto / template argument deduction"
This reverts commit 4d8fff477e.
2021-11-15 00:29:05 +01:00
Matheus Izvekov
4d8fff477e
[clang] retain type sugar in auto / template argument deduction
This implements the following changes:
* AutoType retains sugared deduced-as-type.
* Template argument deduction machinery analyses the sugared type all the way
down. It would previously lose the sugar on first recursion.
* Undeduced AutoType will be properly canonicalized, including the constraint
template arguments.
* Remove the decltype node created from the decltype(auto) deduction.

As a result, we start seeing sugared types in a lot more test cases,
including some which showed very unfriendly `type-parameter-*-*` types.

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

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D110216
2021-11-13 03:35:22 +01:00
Adrian Kuegel
1d7fdbbc18 Revert "[clang] retain type sugar in auto / template argument deduction"
This reverts commit 9b6036deed.
Breaks two libc++ tests.
2021-11-12 13:21:59 +01:00
Matheus Izvekov
9b6036deed
[clang] retain type sugar in auto / template argument deduction
This implements the following changes:
* AutoType retains sugared deduced-as-type.
* Template argument deduction machinery analyses the sugared type all the way
down. It would previously lose the sugar on first recursion.
* Undeduced AutoType will be properly canonicalized, including the constraint
template arguments.
* Remove the decltype node created from the decltype(auto) deduction.

As a result, we start seeing sugared types in a lot more test cases,
including some which showed very unfriendly `type-parameter-*-*` types.

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

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D110216
2021-11-12 01:16:31 +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