1719 Commits

Author SHA1 Message Date
Mariya Podchishchaeva
88d0b0835d
[MS][clang] Revert vector deleting destructors support (#135611)
Finding operator delete[] is still problematic, without it the extension
is a security hazard, so reverting until the problem with operator
delete[] is figured out.

This reverts the following PRs:
Reland [MS][clang] Add support for vector deleting destructors (llvm#133451)
[MS][clang] Make sure vector deleting dtor calls correct operator delete (llvm#133950)
[MS][clang] Fix crash on deletion of array of pointers (llvm#134088)
[clang] Do not diagnose unused deleted operator delete[] (llvm#134357)
[MS][clang] Error about ambiguous operator delete[] only when required (llvm#135041)
2025-04-14 14:17:36 +02:00
Oliver Hunt
1cd59264aa
[RFC] Initial implementation of P2719 (#113510)
This is a basic implementation of P2719: "Type-aware allocation and
deallocation functions" described at http://wg21.link/P2719

The proposal includes some more details but the basic change in
functionality is the addition of support for an additional implicit
parameter in operators `new` and `delete` to act as a type tag. Tag is
of type `std::type_identity<T>` where T is the concrete type being
allocated. So for example, a custom type specific allocator for `int`
say can be provided by the declaration of

  void *operator new(std::type_identity<int>, size_t, std::align_val_t);
  void  operator delete(std::type_identity<int>, void*, size_t, std::align_val_t);

However this becomes more powerful by specifying templated declarations,
for example

template <typename T> void *operator new(std::type_identity<T>, size_t, std::align_val_t);
template <typename T> void operator delete(std::type_identity<T>, void*, size_t, std::align_val_t););

Where the operators being resolved will be the concrete type being
operated over (NB. A completely unconstrained global definition as above
is not recommended as it triggers many problems similar to a general
override of the global operators).

These type aware operators can be declared as either free functions or
in class, and can be specified with or without the other implicit
parameters, with overload resolution performed according to the existing
standard parameter prioritisation, only with type parameterised
operators having higher precedence than non-type aware operators. The
only exception is destroying_delete which for reasons discussed in the
paper we do not support type-aware variants by default.
2025-04-10 17:13:10 -07:00
Mariya Podchishchaeva
2b3aa56fd7
[MS][clang] Error about ambiguous operator delete[] only when required (#135041)
And issue was reported in

https://github.com/llvm/llvm-project/pull/133950#issuecomment-2787510484
. Since we don't always emit vector deleting dtors, only error out about
ambiguous operator delete[] when it will be required for vector deleting
dtor emission.
2025-04-10 15:02:21 +02:00
Liao Chunyu
43bb6bac2f [clang] Fix GCC -Wparentheses warning. NFC.
Without this gcc warned like:
clang/lib/Sema/SemaExprCXX.cpp:4656:74: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
 4655 |              From->isNullPointerConstant(Context,
      |              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 4656 |                                          Expr::NPC_ValueDependentIsNull) &&
      |                                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
 4657 |                  "Expr must be null pointer constant!");
      |                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2025-04-08 23:42:27 -04:00
Mariya Podchishchaeva
16a1d5d51f
[clang] Do not diagnose unused deleted operator delete[] (#134357)
For vector deleting dtors support we now also search and save operator
delete[]. Avoid diagnosing deleted operator delete[] when doing that
because vector deleting dtors are only called when delete[] is present
and whenever delete[] is present in the TU it will be diagnosed
correctly.

Fixes https://github.com/llvm/llvm-project/issues/134265
2025-04-04 14:44:44 +02:00
Matheus Izvekov
cfee056b4e
[clang] NFC: introduce UnsignedOrNone as a replacement for std::optional<unsigned> (#134142)
This introduces a new class 'UnsignedOrNone', which models a lite
version of `std::optional<unsigned>`, but has the same size as
'unsigned'.

This replaces most uses of `std::optional<unsigned>`, and similar
schemes utilizing 'int' and '-1' as sentinel.

Besides the smaller size advantage, this is simpler to serialize, as its
internal representation is a single unsigned int as well.
2025-04-03 14:27:18 -03:00
Mariya Podchishchaeva
8a691cc615
[MS][clang] Make sure vector deleting dtor calls correct operator delete (#133950)
During additional testing I spotted that vector deleting dtor calls
operator delete, not operator delete[] when performing array deletion.
This patch fixes that.
2025-04-02 09:25:43 +02:00
Matheus Izvekov
ad1ca5f4a2
[clang] Concepts: support pack expansions for type constraints (#132626)
This reverts an earlier attempt
(adb0d8ddceb143749c519d14b8b31b481071da77 and
50e5411e4247421fd606f0a206682fcdf0303ae3) to support these expansions,
which was limited to type arguments and which subverted the purpose
of SubstTemplateTypeParmType.

This propagates the ArgumentPackSubstitutionIndex along with the
AssociatedConstraint, so that the pack expansion works, without
needing any new transforms or otherwise any changes to the template
instantiation process.

This keeps the tests from the reverted commits, and adds a few more
showing the new solution also works for NTTPs.

Fixes https://github.com/llvm/llvm-project/issues/131798
2025-04-01 21:11:56 -03:00
Matheus Izvekov
dc17429ae6
[clang] improved preservation of template keyword (#133610) 2025-04-01 17:15:18 -03:00
NAKAMURA Takumi
291fd8f2ce clang/lib/Sema/SemaExprCXX.cpp: Suppress a warning introduced in #133113. [-Wunused-but-set-variable] 2025-03-27 13:34:29 +09:00
Matheus Izvekov
a942d7f810
[clang] fix deduction of member pointers with dependent named classes (#133113)
This fixes a regression when interpreting a nested name specifier for
deduction purposes in member pointers.

This introduces a helper for fully translating a nested name specifier
into a type.

This regression was introduced here:
https://github.com/llvm/llvm-project/pull/130537
and was reported here:
https://github.com/llvm/llvm-project/pull/132401#issuecomment-2751489581

No release notes, since this regression was never released.
2025-03-26 15:51:41 -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
1416566449
Reland: [clang] NFC: Clear some uses of MemberPointerType::getClass (#132317)
Relands Original PR: https://github.com/llvm/llvm-project/pull/131965
Addresses
https://github.com/llvm/llvm-project/pull/131965#issuecomment-2741619498
* Fixes isIncompleteType for injected classes

This clears up some uses of getClass on MemberPointerType when
equivalent uses of getMostRecentCXXRecordDecl would be just as simple or
simpler.
    
This is split-off from a larger patch which removes getClass, in order
to facilitate review.
2025-03-21 10:54:24 -03:00
Matheus Izvekov
335a4614de
Revert "[clang] NFC: Clear some uses of MemberPointerType::getClass" (#132281)
Reverts llvm/llvm-project#131965

Reverted due to issue reported here:
https://github.com/llvm/llvm-project/pull/131965#issuecomment-2741619498
2025-03-20 17:54:21 -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
Mariya Podchishchaeva
392b8f3e63
[clang] Handle Binary StingLiteral kind in one more place (#132201)
The bots are upset by https://github.com/llvm/llvm-project/pull/127629 .
Fix that.
2025-03-20 16:13:54 +01:00
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
Matheus Izvekov
fd7be0d2e9
[clang] NFC: Clear some uses of MemberPointerType::getClass (#131965) 2025-03-19 21:36:10 -03:00
cor3ntin
bc8b19c757
[Clang] Introduce a trait to determine the structure binding size (#131515)
Introduce a trait to determine the number of bindings that would be
produced by

```cpp

   auto [...p] = expr;

```

This is necessary to implement P2300
(https://eel.is/c++draft/exec#snd.concepts-5), but can also be used to
implement a general get<N> function that supports aggregates

`__builtin_structured_binding_size` is a unary type trait that evaluates
to the number of bindings in a decomposition

If the argument cannot be decomposed, a sfinae-friendly error is
produced.

A type is considered a valid tuple if `std::tuple_size_v<T>` is a valid
expression, even if there is no valid `std::tuple_element`
specialization or suitable `get` function for that type.


Fixes #46049
2025-03-18 20:50:56 +01:00
Nikolas Klauser
9598f74133
[Clang] Remove __is_referenceable builtin (#123078)
`__is_referenceable` is almost unused in the wild, and the few cases I
was able to find had checks around them. Since the places in the
standard library where `__is_referenceable` is used have bespoke
builtins, it doesn't make a ton of sense to keep this builtin around.

`__is_referenceable` has been documented as deprecated in Clang 20.
2025-02-06 15:04:23 +01:00
Krystian Stasiowski
5ede7b6a6b
Revert "Reapply "[Clang][Sema] Use the correct lookup context when building overloaded 'operator->' in the current instantiation (#104458)"" (#123982)
Reverts llvm/llvm-project#109422
2025-01-22 14:18:07 -05:00
Krystian Stasiowski
195a1fc5b0
Reapply "[Clang][Sema] Use the correct lookup context when building overloaded 'operator->' in the current instantiation (#104458)" (#109422)
Reapplies #104458, fixing a bug that occurs when a class member access expression calls an `operator->` operator function that returns a non-dependent class type.
2025-01-22 13:13:40 -05:00
Aaron Ballman
5ff7f479a1
[C++20] Destroying delete and deleted destructors (#118800)
When a destroying delete overload is selected, the destructor is not
automatically called. Therefore, the destructor can be deleted without
causing the program to be ill-formed.

Fixes #46818
2025-01-09 08:29:19 -05:00
Sirraide
eb5c21108f
[Clang] [Sema] Support matrix types in pseudo-destructor expressions (#117483)
We already support vector types, and since matrix element types have to
be scalar types, there should be no problem w/ just enabling this.

This now also allows matrix types to be stored in STL containers.
2024-12-17 06:49:31 +01:00
cor3ntin
6d759f83eb
[Clang] Deleting an incomplete enum type is not an error (#119077)
The changes introduced in #97733 accidentally prevented to delete an
incomplete enum
(the validity of which has been confirmed by CWG2925
    
Fixes #99278
2024-12-09 10:20:16 +01:00
cor3ntin
bcf6f84763
Revert "[Clang] Deleting an incomplete enum type is not an error (#118455) (#118980)
This reverts commit 8271195de05742ed7079d7882fbebc2daecbd7e2.
2024-12-07 04:22:47 +01:00
cor3ntin
8271195de0
[Clang] Deleting an incomplete enum type is not an error (#118455)
The changes introduced in #97733 accidentally prevented to delete an
incomplete enum (the validity of which has been confirmed by CWG2925

Fixes #99278
2024-12-04 15:31:19 +01:00
Sarah Spall
46de3a7064
[HLSL] get inout/out ABI for array parameters working (#111047)
Get inout/out parameters working for HLSL Arrays.
Utilizes the fix from #109323, and corrects the assignment behavior
slightly to allow for Non-LValues on the RHS.
Closes #106917

---------

Co-authored-by: Chris B <beanz@abolishcrlf.org>
2024-12-03 17:43:36 -08:00
Joshua Batista
ee0ca4e81f
[HLSL] Add implicit resource element type concepts to AST (#116413)
This PR is step one on the journey to implement resource element type
validation via C++20 concepts. The PR sets up the infrastructure for
injecting implicit concept decls / concept specialization expressions
into the AST, which will then be evaluated after template arguments are
instantiated. This is not meant to be a complete implementation of the
desired validation for HLSL,
there are a couple of missing elements:

We need the __builtin_hlsl_is_typed_resource_element_compatible builtin
to be implemented.
We need other constraints, like is_intangible
We need to put the first 2 points together, and construct a finalized
constraint expression, which should differ between typed and raw buffers
This is just an initial PR that puts some of the core infrastructure in
place.

This PR is an edit of #112600, so that new tests that were put into main
don't fail
Fixes #75676
2024-11-22 09:47:29 -08:00
Joseph Huber
b9d678d22f
[Clang] Use TargetInfo when deciding if an address space is compatible (#115777)
Summary:
Address spaces are used in several embedded and GPU targets to describe
accesses to different types of memory. Currently we use the address
space enumerations to control which address spaces are considered
supersets of eachother, however this is also a target level property as
described by the C standard's passing mentions. This patch allows the
address space checks to use the target information to decide if a
pointer conversion is legal. For AMDGPU and NVPTX, all supported address
spaces can be converted to the default address space.

More semantic checks can be added on top of this, for now I'm mainly
looking to get more standard semantics working for C/C++. Right now the
address space conversions must all be done explicitly in C/C++ unlike
the offloading languages which define their own custom address spaces
that just map to the same target specific ones anyway. The main question
is if this behavior is a function of the target or the language.
2024-11-15 06:58:36 -06:00
Sirraide
dde802b153
[Clang] [NFC] Refactor AST visitors in Sema and the static analyser to use DynamicRecursiveASTVisitor (#115144)
This pr refactors all recursive AST visitors in `Sema`, `Analyze`, and
`StaticAnalysis` to inherit from DRAV instead. This is over half of the
visitors that inherit from RAV directly.

See also #115132, #110040, #93462

LLVM Compile-Time Tracker link for this branch:
https://llvm-compile-time-tracker.com/compare.php?from=5adb5c05a2e9f31385fbba8b0436cbc07d91a44d&to=b58e589a86c06ba28d4d90613864d10be29aa5ba&stat=instructions%3Au
2024-11-15 08:04:08 +01:00
Joshua Batista
b509eb7740
[HLSL] add IsTypedResourceElementCompatible type trait (#114864)
This PR implements a new type trait as a builtin,
__builtin_hlsl_is_typed_resource_element_compatible
This type traits verifies that the given input type is suitable as a
typed resource element type.
It checks that the given input type is homogeneous, has no more than 4
sub elements, does not exceed 16 bytes, and does not contain any arrays,
booleans, or enums.
Fixes an issue in https://github.com/llvm/llvm-project/pull/113730 that
needed to cause that PR to be reverted.
Fixes https://github.com/llvm/llvm-project/issues/113223
2024-11-05 10:05:02 -08:00
Joshua Batista
2c682272ae
Revert "[HLSL] add IsTypedResourceElementCompatible type trait" (#114853)
Reverts llvm/llvm-project#113730
Reverting because test compiler-rt default failed, with:
error: comparison of different enumeration types ('Kind' and
'clang::Type::TypeClass')
2024-11-04 11:14:04 -08:00
Joshua Batista
4894c67230
[HLSL] add IsTypedResourceElementCompatible type trait (#113730)
This PR implements a new type trait as a builtin,
`__builtin_hlsl_is_typed_resource_element_compatible`
This type traits verifies that the given input type is suitable as a
typed resource element type.
It checks that the given input type is homogeneous, has no more than 4
sub elements, does not exceed 16 bytes, and does not contain any arrays,
booleans, or enums.
Fixes #113223
2024-11-04 10:31:58 -08:00
Helena Kotas
9b984554d7
[HLSL][NFC] Move IsIntangibleType from SemaHLSL to Type to make it accessible outside of Sema (#113206)
Moves `IsIntangibleType` from SemaHLSL to Type class and renames it to
`isHLSLIntangibleType`. The existing `isHLSLIntangibleType` is renamed
to `isHLSLBuiltinIntangibleType` and updated to return true only for the
builtin `__hlsl_resource_t` type.

This change makes `isHLSLIntangibleType` functionality accessible
outside of Sema, for example from clang CodeGen.
2024-10-22 16:32:09 -07:00
Vlad Serebrennikov
8536c2e9a2
[clang][NFC] Move concepts::createSubstDiagAt from AST to Sema (#113294)
This fixes layering violation introduced in
2fd01d75a863184766ee0c82b5c0fc8be172448a. The declaration is moved to
`SemaTemplateInstantiate` section of `Sema.h`, after the file where it's
implemented.
2024-10-22 22:18:25 +04:00
awson
37bd788138
[Clang][Sema] Fix templated array size calculation. (#96464)
The [last attempt](https://github.com/llvm/llvm-project/pull/89036) to
fix https://github.com/llvm/llvm-project/issues/41441 has been reverted
immediately.

Here I'm trying the simplest idea I've been able to come with: skip
handling dependent case in `BuildCXXNew`.

The original test (borrowed form
https://github.com/llvm/llvm-project/pull/89036) passes.

Also I've created and added to the tests a minimal repro of the code
https://github.com/llvm/llvm-project/pull/89036 fails on. This
(obviously) also passes.
2024-10-15 07:52:02 +02:00
Younan Zhang
3733b0cff3
[Clang] Fix a DeclContext mismatch when parsing nested lambda parameters (#112177)
When parsing its function parameters, we don't change the CurContext to
the lambda's function declaration. However,
CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures() has not
yet adapted to such behavior when nested lambdas come into play.
Consider the following case,

    struct Foo {};

    template <int, Foo f> struct Arr {};

    constexpr void foo() {
      constexpr Foo F;
      [&]<int I>() {
         [&](Arr<I, F>) {};
       }.template operator()<42>();
    }

As per [basic.def.odr]p5.2, the use of F constitutes an ODR-use. And
per [basic.def.odr]p10, F should be ODR-usable in that interleaving
scope.

We failed to accept the case because the call to tryCaptureVariable()
in getStackIndexOfNearestEnclosingCaptureCapableLambda() suggested
that F is needlessly captureable. That was due to a missed handling
for AfterParameterList in FunctionScopeIndexToStopAt, where it still
presumed DC and LSI matched.

Fixes #47400
Fixes #90896
2024-10-15 12:52:31 +08:00
Erich Keane
c8554e13ee
Turn -Wdeprecated-literal-operator on by default (#111027)
It would be nice to see what our users think about this change, as this
is something that WG21/EWG quite wants to fix a handful of questionable
issues with UB. Depending on the outcome of this after being committed,
we might instead suggest EWG undeprecate this, and require a bit of
'magic' from the lexer.

Additionally, this patch makes it so we emit this diagnostic ALSO in
cases where the literal name is reserved. It doesn't make sense to limit
that.

---------

Co-authored-by: Vlad Serebrennikov <serebrennikov.vladislav@gmail.com>
2024-10-11 06:10:03 -07:00
cor3ntin
1ad5f315ae
[Clang] Avoid a crash when parsing an invalid pseudo-destructor (#111666)
Fixes #111460.
2024-10-09 15:45:16 +02:00
c8ef
679be52709
[Clang][NFC] Consolidate the parameter check for the requires expression parameter. (#110773)
This patch is a follow-up to #109831. In the discussion, we agreed that
having parameter checks scattered across different areas isn't ideal.
Therefore, I suggest merging the check from #88974 into the void
parameter check. This change won't impact functionality and will enhance
maintainability.
2024-10-02 12:01:31 +08:00
c8ef
bb78a0b334
[clang] Fix the local parameter of void type inside the Requires expression. (#109831)
Fixes #109538.

In this patch, we introduce diagnostic for required expression
parameters in the same way as function parameters, fix the issue of
handling void type parameters, and align the behavior with GCC and other
compilers.
2024-10-01 06:39:10 -07:00
yronglin
060137038a
Reapply "[Clang][CWG1815] Support lifetime extension of temporary created by aggregate initialization using a default member initializer" (#108039)
The PR reapply https://github.com/llvm/llvm-project/pull/97308. 

- Implement [CWG1815](https://wg21.link/CWG1815): Support lifetime
extension of temporary created by aggregate initialization using a
default member initializer.

- Fix crash that introduced in
https://github.com/llvm/llvm-project/pull/97308. In
`InitListChecker::FillInEmptyInitForField`, when we enter
rebuild-default-init context, we copy all the contents of the parent
context to the current context, which will cause the `MaybeODRUseExprs`
to be lost. But we don't need to copy the entire context, only the
`DelayedDefaultInitializationContext` was required, which is used to
build `SourceLocExpr`, etc.

---------

Signed-off-by: yronglin <yronglin777@gmail.com>
2024-09-12 06:29:48 +08:00
Chris B
a29afb754f
[HLSL] Allow truncation to scalar (#104844)
HLSL allows implicit conversions to truncate vectors to scalar
pr-values. These conversions are scored as vector truncations and should
warn appropriately.

This change allows forming a truncation cast to a pr-value, but not an
l-value. Truncating a vector to a scalar is performed by loading the
first element of the vector and disregarding the remaining elements.

Fixes #102964
2024-09-11 17:27:09 -05:00
Nikolas Klauser
6dbdb8430b
[Clang] Fix crash due to invalid source location in __is_trivially_equality_comparable (#107815)
Fixes #107777
2024-09-11 08:47:24 +02:00
Nikita Popov
3681d8552f Revert "[Clang][Sema] Use the correct lookup context when building overloaded 'operator->' in the current instantiation (#104458)"
This reverts commit 3cdb30ebbc18fa894d3bd67aebcff76ce7c741ac.

Breaks clang bootstrap.
2024-09-09 21:10:12 +02:00
Krystian Stasiowski
3cdb30ebbc
[Clang][Sema] Use the correct lookup context when building overloaded 'operator->' in the current instantiation (#104458)
Currently, clang erroneously rejects the following:
```
struct A
{
    template<typename T>
    void f();
};

template<typename T>
struct B
{
    void g()
    {
        (*this)->template f<int>(); // error: no member named 'f' in 'B<T>'
    }

    A* operator->();
};
```

This happens because `Sema::ActOnStartCXXMemberReference` does not adjust the `ObjectType` parameter when `ObjectType` is a dependent type (except when the type is a `PointerType` and the class member access is the `->` form). Since the (possibly adjusted) `ObjectType` parameter (`B<T>` in the above example) is passed to `Parser::ParseOptionalCXXScopeSpecifier`, we end up looking up `f` in `B` rather than `A`. 

This patch fixes the issue by identifying cases where the type of the object expression `T` is a dependent, non-pointer type and:
- `T` is the current instantiation and lookup for `operator->` finds a member of the current instantiation, or
- `T` has at least one dependent base case, and `operator->` is not found in the current instantiation

and using `ASTContext::DependentTy` as the type of the object expression when the optional _nested-name-specifier_ is parsed.

Fixes #104268.
2024-09-09 12:06:45 -04:00