188 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
Yanzuo Liu
c4cc3573d1
[Clang][AST][NFC] (RecordDecl -> CXXRecordDecl)::isInjectedClassName (#148195)
Move `RecordDecl::isInjectedClassName` to
`CXXRecordDecl::isInjectedClassName`. C language doesn't have the term
"injected class name".

Co-authored-by: Matheus Izvekov <mizvekov@gmail.com>
2025-07-12 21:13:30 +08:00
Kazu Hirata
12af64d0d7
[Sema] Remove unused includes (NFC) (#141419)
These are identified by misc-include-cleaner.  I've filtered out those
that break builds.  Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.
2025-05-25 10:55:32 -07:00
Vlad Serebrennikov
001cc34275
[clang] Add scoped enum support to StreamingDiagnostic (#138089)
This patch adds templated `operator<<` for diagnostics that pass scoped
enums, saving people from `llvm::to_underlying()` clutter on the side of
emitting the diagnostic. This eliminates 80 out of 220 usages of
`llvm::to_underlying()` in Clang.

I also backported `std::is_scoped_enum_v` from C++23.
2025-05-01 17:03:47 +04:00
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
Matheus Izvekov
6003c3055a
[clang] NFC: Unify implementations of CheckMemberPointerConversion (#131966)
This deduplicates the implementation of CheckMemberPointerConversion
accross SemaCast and SemaOverload.
2025-03-19 22:48:49 -03:00
Younan Zhang
d9110858ee
[Clang] Fix an incorrect assumption on getTemplatedDecl() (#131559)
Since a68d20e98, we've been calling HandleDelayedAccessCheck() for
concept declarations when the declaration contains invalid member
accesses.

However, a concept declaration is TemplateDecl such that doesn't contain
any TemplatedDecl.

Fixes https://github.com/llvm/llvm-project/issues/131530
2025-03-17 16:53:57 +08:00
Kazu Hirata
46d750be2e
[Sema] Remove unused includes (NFC) (#116461)
Identified with misc-include-cleaner.
2024-11-16 07:37:33 -08:00
Vlad Serebrennikov
bae2c54912 [clang][NFC] Move documentation of Sema functions into Sema.h
This patch moves documentation of `Sema` functions from `.cpp` files to `Sema.h` when there was no documentation in the latter, or it can be trivially subsumed. More complicated cases when there's less trivial divergence between documentation attached to declaration and the one attached to implementation are left for a later PR that would require review.

It appears that doxygen can find the documentation for a function defined out-of-line even if it's attached to an implementation, and not declaration. But other tools, e.g. clangd, are not as powerful. So this patch significantly improves autocompletion experience for (at least) clangd-based IDEs.
2024-07-01 20:55:57 +03:00
Qizhi Hu
200f3bd395
[Clang][Sema] access checking of friend declaration should not be delayed (#91430)
attempt to fix https://github.com/llvm/llvm-project/issues/12361
Consider this example:
```cpp
class D {
    class E{
        class F{};
        friend  void foo(D::E::F& q);
        };
    friend  void foo(D::E::F& q);
    };

void foo(D::E::F& q) {}
```
The first friend declaration of foo is correct. After that, the second
friend declaration delayed access checking and set its previous
declaration to be the first one. When doing access checking of `F`(which
is private filed of `E`), we put its canonical declaration(the first
friend declaration) into `EffectiveContext.Functions`. Actually, we are
still checking the first one. This is incorrect due to the delayed
checking.
Creating a new scope to indicate we are parsing a friend declaration and
doing access checking in time.
2024-05-10 20:14:08 +08:00
Vlad Serebrennikov
d019b9aaaa [clang][NFC] Refactor CXXSpecialMember
In preparation for `SemaCUDA`, which requires this enum to be forward-declarable.
2024-04-12 12:21:14 +03:00
Manna, Soumi
b4fbc4bdbf [NFC][Clang][Coverity] Fix Static Code Analysis Concerns with copy without assign
This patch adds copy/move assignment operator to the class which has user-defined copy/move constructor.

Reviewed By: tahonermann, NoQ, aaronpuchert

Differential Revision: https://reviews.llvm.org/D150411
2023-05-18 18:14:07 -07:00
Alan Zhao
9b4faa11c6 [clang] Fix overly aggressive lifetime checks for parenthesized aggregate initialization
Before this patch, initialized class members would have the LifetimeKind
LK_MemInitializer, which does not allow for binding a temporary to a
reference. Binding to a temporary however is allowed in parenthesized
aggregate initialization, even if it leads to a dangling reference. To
fix this, we create a new EntityKind, EK_ParenAggInitMember, which has
LifetimeKind LK_FullExpression.

This patch does *not* attempt to diagnose dangling references as a
result of using this feature.

This patch also refactors TryOrBuildParenListInitialization(...) to
accomodate creating different InitializedEntity objects.

Fixes #61567

[0]: https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0960r3.html

Reviewed By: shafik

Differential Revision: https://reviews.llvm.org/D148274
2023-05-01 10:02:15 -07:00
Utkarsh Saxena
9e0474fbb9 Perform access checking to private members in simple requirement.
> Dependent access checks.

Fixes: https://github.com/llvm/llvm-project/issues/53364

We previously ignored dependent access checks to private members.
These are visible only to the `RequiresExprBodyExpr` (through `PerformDependentDiagnositcs`) and not to the individual requirements.

---

> Non-dependent access checks.
Fixes: https://github.com/llvm/llvm-project/issues/53334
Access to members in a non-dependent context would always yield an
invalid expression. When it appears in a requires-expression, then this
is a hard error as this would always result in a substitution failure.

https://eel.is/c++draft/expr.prim.req#general-note-1
> Note 1: If a requires-expression contains invalid types or expressions in its requirements, and it does not appear within the declaration of a templated entity, then the program is ill-formed. — end note]
> If the substitution of template arguments into a requirement would always result in a substitution failure, the program is ill-formed; no diagnostic required.

The main issue here is the delaying of the diagnostics.
Use a `ParsingDeclRAIIObject` creates a separate diagnostic pool for diagnositcs associated to the `RequiresExprBodyDecl`.
This is important because dependent diagnostics should not be leaked/delayed to higher scopes (Eg. inside a template function or in a trailing requires). These dependent diagnostics must be attached to the `DeclContext` of the parameters of `RequiresExpr` (which is the `RequiresExprBodyDecl` in this case).
Non dependent diagnostics, on the other hand, should not delayed and surfaced as hard errors.

Differential Revision: https://reviews.llvm.org/D140547
2023-01-11 12:13:16 +01:00
Corentin Jabot
c151225096 [C++2b] Implement multidimentional subscript operator
Implement P2128R6 in C++23 mode.

Unlike GCC's implementation, this doesn't try to recover when a user
meant to use a comma expression.

Because the syntax changes meaning in C++23, the patch is *NOT*
implemented as an extension. Instead, declaring an array with not
exactly 1 parameter is an error in older languages modes. There is an
off-by-default extension warning in C++23 mode.

Unlike the standard, we supports default arguments;

Ie, we assume, based on conversations in WG21, that the proposed
resolution to CWG2507 will be accepted.

We allow arrays OpenMP sections and C++23 multidimensional array to
coexist:

[a , b] multi dimensional array
[a : b] open mp section
[a, b: c] // error

The rest of the patch is relatively straight forward: we take care to
support an arbitrary number of arguments everywhere.
2022-02-08 12:10:47 -05:00
Kazu Hirata
d409048201 [Sema] Use llvm::is_contained (NFC) 2021-10-11 11:06:44 -07:00
Nathan Sidwell
ddda05add5 [clang][NFC] Break out BaseUsingDecl from UsingDecl
This is a pre-patch for adding using-enum support.  It breaks out
the shadow decl handling of UsingDecl to a new intermediate base
class, BaseUsingDecl, altering the decl hierarchy to

def BaseUsing : DeclNode<Named, "", 1>;
  def Using : DeclNode<BaseUsing>;
def UsingPack : DeclNode<Named>;
def UsingShadow : DeclNode<Named>;
  def ConstructorUsingShadow : DeclNode<UsingShadow>;

Differential Revision: https://reviews.llvm.org/D101777
2021-06-07 06:29:28 -07:00
Richard Smith
d38057f3ec Treat implicit deduction guides as being equivalent to their
corresponding constructor for access checking purposes.
2021-05-19 13:31:53 -07:00
Haojian Wu
7ad6c8414c [clang] Fix an assertion crash in delayed access check.
`TD->getTemplatedDecl()` might not be a DeclContext variant, which can
trigger an assertion inside `isa<>`.

Differential Revision: https://reviews.llvm.org/D91380
2020-11-13 14:02:57 +01:00
Richard Smith
8e0c9e21bf [c++20] Delete defaulted comparison functions if they would invoke an
inaccessible comparison function.
2019-12-10 19:28:30 -08:00
Simon Pilgrim
dc4d908d6e Sema - silence static analyzer getAs<> null dereference warnings. NFCI.
The static analyzer is warning about potential null dereferences, but in these cases we should be able to use castAs<> directly and if not assert will fire for us.

llvm-svn: 373911
2019-10-07 14:25:46 +00:00
Simon Pilgrim
1cd399c915 Silence static analyzer getAs<RecordType> null dereference warnings. NFCI.
The static analyzer is warning about potential null dereferences, but in these cases we should be able to use castAs<RecordType> directly and if not assert will fire for us.

llvm-svn: 373584
2019-10-03 11:22:48 +00:00
Fangrui Song
75e74e077c Range-style std::find{,_if} -> llvm::find{,_if}. NFC
llvm-svn: 357359
2019-03-31 08:48:19 +00:00
Chandler Carruth
2946cd7010 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
2019-01-19 08:50:56 +00:00
Ilya Biryukov
98397555a5 [CodeComplete] Fix a crash in access checks of inner classes
Summary: The crash was introduced in r348135.

Reviewers: kadircet

Reviewed By: kadircet

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D55260

llvm-svn: 348387
2018-12-05 17:38:39 +00:00
Ilya Biryukov
f1822ec431 [CodeComplete] Cleanup access checking in code completion
Summary: Also fixes a crash (see the added 'accessibility-crash.cpp' test).

Reviewers: ioeric, kadircet

Reviewed By: kadircet

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D55124

llvm-svn: 348135
2018-12-03 13:29:17 +00:00
Richard Smith
5c9b3b7576 P0969R0: allow structured binding of accessible members, not only public members.
llvm-svn: 343036
2018-09-25 22:12:44 +00:00
Fangrui Song
6907ce2f8f Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338291
2018-07-30 19:24:48 +00:00
Eric Liu
18b404a521 [CodeComplete] Fix accessibilty of protected members from base class.
Summary:
Currently, protected members from base classes are marked as
inaccessible when completing in derived class. This patch fixes the problem by
setting the naming class correctly when looking up results in base class
according to [11.2.p5].

Reviewers: aaron.ballman, sammccall, rsmith

Reviewed By: aaron.ballman

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D49421

llvm-svn: 337453
2018-07-19 13:32:00 +00:00
Adrian Prantl
9fc8faf9e6 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
2018-05-09 01:00:01 +00:00
Hans Wennborg
02d3361c38 Revert r325321 "[Sema] Take into account the current context when checking the"
This broke the Chromium build, see https://crbug.com/813017

> accessibility of a class member.
>
> This fixes PR32898.
>
> rdar://problem/33737747
>
> Differential revision: https://reviews.llvm.org/D36918

llvm-svn: 325335
2018-02-16 12:06:32 +00:00
Akira Hatanaka
82443d365f [Sema] Take into account the current context when checking the
accessibility of a class member.

This fixes PR32898.

rdar://problem/33737747

Differential revision: https://reviews.llvm.org/D36918

llvm-svn: 325321
2018-02-16 08:47:37 +00:00
Richard Smith
5179eb7821 P0136R1, DR1573, DR1645, DR1715, DR1736, DR1903, DR1941, DR1959, DR1991:
Replace inheriting constructors implementation with new approach, voted into
C++ last year as a DR against C++11.

Instead of synthesizing a set of derived class constructors for each inherited
base class constructor, we make the constructors of the base class visible to
constructor lookup in the derived class, using the normal rules for
using-declarations.

For constructors, UsingShadowDecl now has a ConstructorUsingShadowDecl derived
class that tracks the requisite additional information. We create shadow
constructors (not found by name lookup) in the derived class to model the
actual initialization, and have a new expression node,
CXXInheritedCtorInitExpr, to model the initialization of a base class from such
a constructor. (This initialization is special because it performs real perfect
forwarding of arguments.)

In cases where argument forwarding is not possible (for inalloca calls,
variadic calls, and calls with callee parameter cleanup), the shadow inheriting
constructor is not emitted and instead we directly emit the initialization code
into the caller of the inherited constructor.

Note that this new model is not perfectly compatible with the old model in some
corner cases. In particular:
 * if B inherits a private constructor from A, and C uses that constructor to
   construct a B, then we previously required that A befriends B and B
   befriends C, but the new rules require A to befriend C directly, and
 * if a derived class has its own constructors (and so its implicit default
   constructor is suppressed), it may still inherit a default constructor from
   a base class

llvm-svn: 274049
2016-06-28 19:03:57 +00:00
Etienne Bergeron
4753302165 [Sema] Fix incorrect enum token namespace
Summary:
This patch fix the scoping of enum literal. They were not resolving
to the right type.

It was not causing any problem as one is a copy of the other one.

The literal in the switch are resolving to Sema.h:5527
```
  enum AccessResult {
    AR_accessible,
    AR_inaccessible,
    AR_dependent,
    AR_delayed
  };
```

Instead of SemaAccess.cpp:27
```
/// A copy of Sema's enum without AR_delayed.
enum AccessResult {
  AR_accessible,
  AR_inaccessible,
  AR_dependent
};
```

This issue was found by a new clang-tidy check (still on-going).

Reviewers: rsmith, aaron.ballman

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D20773

llvm-svn: 271431
2016-06-01 21:17:32 +00:00
Richard Smith
fd55fc86ed Make SemaAccess smarter about determining when a dependent class might
instantiate to match a friend class declaration. It's still pretty dumb,
though.

llvm-svn: 264189
2016-03-23 20:39:06 +00:00
Richard Smith
bbbe618467 Fix crash in access check for aggregate initialization of base classes. It's
not obvious how to access-check these, so pick a conservative rule until we get
feedback from CWG.

llvm-svn: 262966
2016-03-08 23:17:35 +00:00
David Blaikie
8533e96e42 -Wdeprecated: SavedInstanceContext is returned by value but isn't really copyable, but it can be made movable
llvm-svn: 244826
2015-08-12 22:58:10 +00:00
Davide Italiano
9b950d8148 [SemaAccess] Provide meaningful message when we hit llvm_unreachable().
llvm-svn: 243571
2015-07-29 20:55:04 +00:00
Alexander Kornienko
ab9db51042 Revert r240270 ("Fixed/added namespace ending comments using clang-tidy").
llvm-svn: 240353
2015-06-22 23:07:51 +00:00
Alexander Kornienko
3d9d929e42 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

  $ tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
      -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
      work/llvm/tools/clang

To reduce churn, not touching namespaces spanning less than 10 lines.

llvm-svn: 240270
2015-06-22 09:47:44 +00:00
Davide Italiano
24e89664cd [Sema] Improve llvm_unreachable() message.
llvm-svn: 237532
2015-05-17 02:27:10 +00:00
Reid Kleckner
af9bf59ba9 Don't assume friended C++ method decls have qualifiers
There are a few cases where unqualified lookup can find C++ methods.
Unfortunately, none of them seem to have illegal access paths, so I
can't excercise the diagnostic source range code that I am changing
here.

Fixes PR21851, which was a crash on valid.

llvm-svn: 224471
2014-12-17 23:40:46 +00:00
Alp Toker
2afa8780d6 Consolidate some note diagnostics
These note diags have the same message and can be unified further but for now
let's just bring them together.

Incidental change: Display a source range in the final attr diagnostic.

llvm-svn: 209728
2014-05-28 12:20:14 +00:00
Craig Topper
c3ec149bb2 [C++11] Use 'nullptr'. Sema edition.
llvm-svn: 209613
2014-05-26 06:22:03 +00:00
Aaron Ballman
522a6ddf9e [C++11] Replacing CXXRecordDecl iterators friend_begin() and friend_end() with iterator_range friends(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203815
2014-03-13 17:00:06 +00:00
Aaron Ballman
574705ed7f [C++11] Replacing CXXRecordDecl iterators bases_begin() and bases_end() with iterator_range bases(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203803
2014-03-13 15:41:46 +00:00