704 Commits

Author SHA1 Message Date
Alexander Shaposhnikov
6db007a065 [Clang][Sema] Fix comparison of constraint expressions
This diff switches the approach to comparison of constraint expressions
to the new one based on template args substitution.
It continues the effort to fix our handling of out-of-line definitions
of constrained templates.
This is a recommit of 3a54022934.

Differential revision: https://reviews.llvm.org/D146178
2023-05-09 18:14:39 +00:00
Ilya Biryukov
629170fe45 [Sema] Lambdas are not part of immediate context for deduction
This commit implements [temp.deduct]p9.
Test updates include:
- New notes in `cxx1y-init-captures.cpp`, `lambda-expressions.cpp`
  and 'warn-unused-lambda-capture.cpp'.
  This seems to be caused by diagnosing errors earlier (during
  deduction) that were previously surfaced later (during
  instantiation).
- New error `lambda-unevaluated.cpp` is in line with [temp.deduct]p9.

Reviewed By: erichkeane, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D148802
2023-05-09 12:06:33 +02:00
Alexander Shaposhnikov
3b9ed6e532 Revert "[Clang][Sema] Fix comparison of constraint expressions"
This reverts commit 3a540229341e3c8dc6d8ee61309eafaf943ea254.
A new regression is discovered and needs to be investigated.
2023-05-05 00:02:26 +00:00
David Stone
6d6880554c [clang][Sema][NFC] Move EnterExpressionEvaluationContext to its own file
Sema.h is huge. This makes a small reduction to it by moving
EnterExpressionEvaluationContext into a new header, since it is an
independent component.

Differential Revision: https://reviews.llvm.org/D149796
2023-05-04 13:06:53 -04:00
Alexander Shaposhnikov
3a54022934 [Clang][Sema] Fix comparison of constraint expressions
This diff switches the approach to comparison of constraint expressions
to the new one based on template args substitution.
It continues the effort to fix our handling of out-of-line definitions
of constrained templates.
This is a recommit of e3b1083e00.

Differential revision: https://reviews.llvm.org/D146178
2023-05-03 21:06:12 +00:00
Erich Keane
3e850a6eea Revert "[Clang][Sema] Fix comparison of constraint expressions"
This reverts commit e3b1083e00e62f5d157d15cb8c63a1c3dfdf12e2.

This was reverted because it breaks a number of libstdc++ examples, AND
required a workaround that causes hiding of legitimate bugs.
2023-05-02 08:09:35 -07:00
Alexander Shaposhnikov
e3b1083e00 [Clang][Sema] Fix comparison of constraint expressions
This diff switches the approach to comparison of constraint expressions
to the new one based on template args substitution.
It continues the effort to fix our handling of out-of-line definitions
of constrained templates.
This is a recommit of 60bee9ff5445.

Differential revision: https://reviews.llvm.org/D146178
2023-04-27 21:33:32 +00:00
Alexander Shaposhnikov
13d44a8f56 Revert "[Clang][Sema] Fix comparison of constraint expressions"
This temporarily reverts commit
60bee9ff544541e83ffbd4be31923d0e8b644690.
The diff will be recommitted once the newly discovered
regressions are fixed.
2023-04-07 18:41:57 +00:00
Ilya Biryukov
f27b77e5c5 [Sema] Populate declarations inside TypeLocs for some invalid types
This also reverts 282cae0b9a602267ad7ef622f770066491332a11 as the
particular crash is now handled by the new code.

Before this change Clang would always leave declarations inside the
type-locs as `null` if the declarator had an invalid type. This patch
populates declarations even for invalid types if the structure of the
type and the type-locs match.

There are certain cases that may still cause crashes. These happen when
Clang recovers the type in a way that is not reflected in the
declarator's structure, e.g. adding a pointer when it was not present in
the code for ObjC interfaces or ignoring pointers written in the code
in C++ with auto return type (`auto* foo() -> int`). Those cases look
fixable with a better recovery strategy and I plan to follow up with
more patches to address those.

The first attempt caused 31 tests from `check-clang` to crash due to
different structure of the types and type-locs after certain errors. The
good news is that the failure is localized and mismatch in structures is
discovered by assertions inside `DeclaratorLocFiller`. Some notable
cases caught by existing tests:
- Invalid chunks when type is fully ignored and replace with int or now.
  Crashed in `C/C2x/n2838.c`.
- Invalid return types in lambdas. Crashed in `CXX/drs/dr6xx.cpp`.
- Invalid member pointers. Crashed in `CXX/dcl.dcl/dcl.spec/dcl.type/dcl.spec.auto/p3-generic-lambda-1y.cpp`
- ObjC recovery that adds pointers. Crashed in `SemaObjC/blocks.m`

This change also updates the output of `Index/complete-blocks.m`.
Not entirely sure what causes the change, but the new function signature
is closer to the source code, so this seems like an improvement.

Reviewed By: aaron.ballman, erichkeane

Differential Revision: https://reviews.llvm.org/D146971
2023-04-06 19:02:41 +02:00
Alexander Shaposhnikov
60bee9ff54 [Clang][Sema] Fix comparison of constraint expressions
This diff switches the approach to comparison of constraint expressions
to the new one based on template args substitution.
It continues the effort to fix our handling of out-of-line definitions
of constrained templates.

The associated GitHub issue: https://github.com/llvm/llvm-project/issues/61414

Test plan:
1/ ninja check-all
2/ bootstrapped Clang passes tests

Differential revision: https://reviews.llvm.org/D146178
2023-04-04 02:31:13 +00:00
Erich Keane
514e4359a5 inline stmt attribute diagnosing in templates
D146089's author discovered that our diagnostics for always/no inline
would null-dereference when used in a template. He fixed that by
skipping in the dependent case.

This patch makes sure we diagnose these after a template instantiation.
It also adds infrastructure for other statement attributes to add
checking/transformation.

Differential Revision: https://reviews.llvm.org/D146323
2023-03-21 08:16:52 -07:00
Ilya Biryukov
282cae0b9a [Sema] Fix crash on __fp16 parameters in template instantiations
Fixes #61441.

Currently, Clang stores `nullptr` in the parameter lists inside
`FunctionProtoTypeLoc` if `__fp16` is used without pointer qualifiers.

Any code path that calls `Declarator::setInvalidType()` before
`GetFullTypeForDeclarator` will lead to the same problem downstream.

The relevant code is:
```cpp
if (D.isInvalidType())
  return Context.getTrivialTypeSourceInfo(T);

return GetTypeSourceInfoForDeclarator(state, T, TInfo);
```

`GetTypeSourceInfoForDeclarator` sets the parameter `Decl`, but we can't
call it when `isInvalidType() == true` as this causes other assertion
failures that seem harder to fix.

Reviewed By: kadircet

Differential Revision: https://reviews.llvm.org/D146426
2023-03-21 14:06:46 +01:00
Corentin Jabot
93d7002dc4 [Clang] Implement Change scope of lambda trailing-return-type
This implements P2036R3 and P2579R0.
That is, explicit, int, and implicit capture become visible
at the start of the parameter head.

Reviewed By: aaron.ballman, rupprecht, shafik

Differential Revision: https://reviews.llvm.org/D124351
2023-03-02 10:04:16 +01:00
Jordan Rupprecht
74ce297045 Revert "[Clang] Implement Change scope of lambda trailing-return-type"
This reverts commit d708a186b6a9b050d09558163dd353d9f738c82d (and typo fix e4bc9898ddbeb70bc49d713bbf863f050f21e03f). It causes a compilation error for this:

```
struct StringLiteral {
  template <int N>
  StringLiteral(const char (&array)[N])
      __attribute__((enable_if(N > 0 && N == __builtin_strlen(array) + 1,
                               "invalid string literal")));
};

struct Message {
  Message(StringLiteral);
};

void Func1() {
  auto x = Message("x");  // Note: this is fine

  // Note: "xx\0" to force a different type, StringLiteral<3>, otherwise this
  // successfully builds.
  auto y = [&](decltype(Message("xx"))) {};

  // ^ fails with: repro.cc:18:13: error: reference to local variable 'array'
  // declared in enclosing function 'StringLiteral::StringLiteral<3>'

  (void)x;
  (void)y;
}
```

More details posted to D124351.
2023-02-03 08:49:34 -08:00
Corentin Jabot
d708a186b6 [Clang] Implement Change scope of lambda trailing-return-type
This implements P2036R3 and P2579R0.
That is, explicit, int, and implicit capture become visible
at the start of the parameter head.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D124351
2023-01-31 11:06:14 +01:00
v1nh1shungry
ea4fd668c2 [clang] fix crash on generic lambda with lambda in decltype
Relevant issue: https://github.com/llvm/llvm-project/issues/59771

During the instantiation of a generic lambda, a non-generic lambda in
the trailing `decltype` is a `DeclContext` but not a dependent context,
so we shouldn't call `PerformDependentDiagnostics` on it.

Differential Revision: https://reviews.llvm.org/D140838
2023-01-20 17:11:07 +08:00
Kazu Hirata
6ad0788c33 [clang] Use std::optional instead of llvm::Optional (NFC)
This patch replaces (llvm::|)Optional< with std::optional<.  I'll post
a separate patch to remove #include "llvm/ADT/Optional.h".

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-14 12:31:01 -08:00
Kazu Hirata
a1580d7b59 [clang] Add #include <optional> (NFC)
This patch adds #include <optional> to those files containing
llvm::Optional<...> or Optional<...>.

I'll post a separate patch to actually replace llvm::Optional with
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-14 11:07:21 -08:00
Utkarsh Saxena
a3b632ab87 Remove brittle test introduced in D140547. 2023-01-13 20:26:38 +01:00
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
serge-sans-paille
a3c248db87
Move from llvm::makeArrayRef to ArrayRef deduction guides - clang/ part
This is a follow-up to https://reviews.llvm.org/D140896, split into
several parts as it touches a lot of files.

Differential Revision: https://reviews.llvm.org/D141139
2023-01-09 12:15:24 +01:00
Corentin Jabot
ca61961380 Implement CWG2631
Implement https://cplusplus.github.io/CWG/issues/2631.html.

Immediate calls in default arguments and defaults members
are not evaluated.

Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.

The immediate calls are executed by doing a
transform on the initializing expression.

Note that lambdas are not considering subexpressions so
we do not need to transform them.

As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.

Reviewed By: aaron.ballman, #clang-language-wg, rupprecht

Differential Revision: https://reviews.llvm.org/D136554
2023-01-08 10:35:26 +01:00
Utkarsh Saxena
8c0aa53b07 Fix out-of-bound access in TransformNestedRequirement. 2022-12-22 05:20:31 +01:00
Utkarsh Saxena
b3ce872851 Make evaluation of nested requirement consistent with requires expr.
Fixes: https://github.com/llvm/llvm-project/issues/45563
```
template<class T>  concept True = true;

template <class T>
concept C1 = requires (T) {
   requires True<typename T::value> || True<T>;
};

template <class T>
constexpr bool foo()
requires True<typename T::value> || True<T> {
    return true;
}
static_assert(C1<double>); // Previously failed due to SFINAE error
static_assert(foo<int>()); // but this works fine.
```
The issue here is the discrepancy between how a [nested requirement is evaluated](https://github.com/llvm/llvm-project/blob/main/clang/lib/Sema/SemaTemplateInstantiate.cpp#L2331) Vs how a [non-nested requirement is evaluated](https://github.com/llvm/llvm-project/blob/main/clang/lib/Sema/SemaConcept.cpp#L167-L200).

This patch makes constraint checking consistent for nested requirement
and trailing requires expressions by reusing the same evaluator.

Differential Revision: https://reviews.llvm.org/D138914
2022-12-19 20:22:03 +01:00
Krasimir Georgiev
339a7687e1 Revert "Implement CWG2631"
This reverts commit f1f1b60c7ba607e9ffe3bc012161d43ef95ac773.

Temporary revert, possibly triggers a new assertion failure on
QualType::getCommonPtr.
We're working on a reproducer, to follow-up on
https://reviews.llvm.org/D136554.
2022-12-14 09:10:22 +00:00
Corentin Jabot
f1f1b60c7b Implement CWG2631
Implement https://cplusplus.github.io/CWG/issues/2631.html.

Immediate calls in default arguments and defaults members
are not evaluated.

Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.

The immediate calls are executed by doing a
transform on the initializing expression.

Note that lambdas are not considering subexpressions so
we do not need to transform them.

As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D136554
2022-12-13 09:57:05 +01:00
Arthur Eubanks
be305674bf Revert "Implement CWG2631"
This reverts commit c9a6713b4788f10b81202b70993068e475b392f7.

Causes crashes, see D136554.
2022-12-09 14:20:30 -08:00
Corentin Jabot
c9a6713b47 Implement CWG2631
Implement https://cplusplus.github.io/CWG/issues/2631.html.

Immediate calls in default arguments and defaults members
are not evaluated.

Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.

The immediate calls are executed by doing a
transform on the initializing expression.

Note that lambdas are not considering subexpressions so
we do not need to transform them.

As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D136554
2022-12-09 10:25:44 +01:00
Corentin Jabot
49c86eab62 Revert "Implement CWG2631"
This patch causes another link error,
reverting until I can investigate.

This reverts commit a96a6ed83230265f3eab09a94f0e9525d05f8a74.
2022-12-08 19:57:58 +01:00
Corentin Jabot
a96a6ed832 Implement CWG2631
Implement https://cplusplus.github.io/CWG/issues/2631.html.

Immediate calls in default arguments and defaults members
are not evaluated.

Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.

The immediate calls are executed by doing a
transform on the initializing expression.

Note that lambdas are not considering subexpressions so
we do not need to transform them.

As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D136554
2022-12-08 10:32:54 +01:00
Kazu Hirata
8595f2e54d [Sema] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-03 11:13:39 -08:00
Corentin Jabot
9221bedfd7 Revert "Implement CWG2631"
This reverts commit 26fa17ed2914bd80c066d36b325fd3104e45554c.
This reverts commit 4403c4f9e77e673a2771edfc7ab0ebb234e97485.

There is still an ODR issue causing linker errors, investigating.
2022-11-30 16:03:05 +01:00
Corentin Jabot
26fa17ed29 Implement CWG2631
Implement https://cplusplus.github.io/CWG/issues/2631.html.

Immediate calls in default arguments and defaults members
are not evaluated.

Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.

The immediate calls are executed by doing a
transform on the initializing expression.

Note that lambdas are not considering subexpressions so
we do not need to transform them.

As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D136554
2022-11-30 11:25:01 +01:00
Corentin Jabot
35a870c30a Revert "Implement CWG2631"
This reverts commit 7acfe3629479c8489fc2d7f629994dc200be990c.
This reverts commit 5f87a892a7bed9cb0599573b9aaf387bc1df9c14.
This reverts commit 6875ac69279a3a02fab382a2c8d121558ecbfa91.
2022-11-04 22:10:50 +01:00
Corentin Jabot
7acfe36294 Implement CWG2631
Implement https://cplusplus.github.io/CWG/issues/2631.html.

Immediate calls in default arguments and defaults members
are not evaluated.

Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.

The immediate calls are executed by doing a
transform on the initializing expression.

Note that lambdas are not considering subexpressions so
we do not need to transform them.

As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D136554
2022-11-04 14:46:38 +01:00
Corentin Jabot
722a0efe31 Revert "Implement CWG2631"
Breaks the build on some platforms.

This reverts commit bf1e235695a7acdc3e868217e69d5b31ada06cb3.
2022-11-04 08:24:52 +01:00
Corentin Jabot
bf1e235695 Implement CWG2631
Implement https://cplusplus.github.io/CWG/issues/2631.html.

Immediate calls in default arguments and defaults members
are not evaluated.

Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.

The immediate calls are executed by doing a
transform on the initializing expression.

Note that lambdas are not considering subexpressions so
we do not need to transform them.

As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D136554
2022-11-04 07:58:57 +01:00
Liming Liu
ae48d1c76a [P0857R0 Part-B] Allows `require' clauses appearing in
template-template parameters. Although it effects whether a template can be
used as an argument for another template, the constraint seems not to
be checked, nor other major implementations (GCC, MSVC, et al.) check it.

Additionally, Part-A of the document seems to have been implemented.
So mark P0857R0 as completed.

Differential Revision: https://reviews.llvm.org/D134128
2022-10-27 06:41:43 -07:00
Matheus Izvekov
326feaafb0
[clang] Implement sugared substitution changes to infrastructure
Implements the changes required to perform substitution with
non-canonical template arguments, and to 'finalize' them
by not placing 'Subst' nodes.

A finalized substitution means we won't resugar them later,
because these templates themselves were eagerly substituted
with the intended arguments at the point of use. We may still
resugar other templates used within those, though.

This patch does not actually implement any uses of this
functionality, those will be added in subsequent patches,
so expect no changes to existing tests.

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

Differential Revision: https://reviews.llvm.org/D134604
2022-10-27 06:18:07 +02:00
Matheus Izvekov
13fd717b22
[clang] Changes to produce sugared converted template arguments
Makes CheckTemplateArgumentList and the template deduction functions
produce a sugared converted argument list in addition to the canonical one.

This is mostly NFC except that we hook this up to a few diagnostics in
SemaOverload.

The infrastructure here will be used in subsequent patches
where we perform a finalized sugared substitution for entities
which we do not unique per specializations on canonical arguments,
and later on will be used for template specialization resugaring.

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

Differential Revision: https://reviews.llvm.org/D133874
2022-10-27 05:50:00 +02:00
Matheus Izvekov
b1f1ce782c
Revert "[clang] Changes to produce sugared converted template arguments"
This reverts commit 11ce78940b4c6f44ae6ee5a6611d6c9b1bade1c2.
2022-10-26 10:14:40 +02:00
Matheus Izvekov
8383c2a435
Revert "[clang] Implement sugared substitution changes to infrastructure"
This reverts commit c4c2a3c65684e062efcd101a957c6cae0a304a7a.
2022-10-26 10:14:31 +02:00
Matheus Izvekov
c4c2a3c656
[clang] Implement sugared substitution changes to infrastructure
Implements the changes required to perform substitution with
non-canonical template arguments, and to 'finalize' them
by not placing 'Subst' nodes.

A finalized substitution means we won't resugar them later,
because these templates themselves were eagerly substituted
with the intended arguments at the point of use. We may still
resugar other templates used within those, though.

This patch does not actually implement any uses of this
functionality, those will be added in subsequent patches,
so expect no changes to existing tests.

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

Differential Revision: https://reviews.llvm.org/D134604
2022-10-26 03:21:15 +02:00
Matheus Izvekov
11ce78940b
[clang] Changes to produce sugared converted template arguments
Makes CheckTemplateArgumentList and the template deduction functions
produce a sugared converted argument list in addition to the canonical one.

This is mostly NFC except that we hook this up to a few diagnostics in
SemaOverload.

The infrastructure here will be used in subsequent patches
where we perform a finalized sugared substitution for entities
which we do not unique per specializations on canonical arguments,
and later on will be used for template specialization resugaring.

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

Differential Revision: https://reviews.llvm.org/D133874
2022-10-26 02:15:10 +02:00
Erich Keane
975740bf8d "Reapply "GH58368: Correct concept checking in a lambda defined in concept""
This reverts commit cecc9a92cfca71c1b6c2a35c5e302ab649496d11.

The problem ended up being how we were handling the lambda-context in
code generation: we were assuming any decl context here would be a
named-decl, but that isn't the case.  Instead, we just replace it with
the concept's owning context.

Differential Revision: https://reviews.llvm.org/D136451
2022-10-24 12:36:54 -07:00
Erich Keane
cecc9a92cf Revert "Reapply "GH58368: Correct concept checking in a lambda defined in concept"""
This reverts commit b876f6e2f28779211a829d7d4e841fe68885ae20.

Still getting build failures on PPC AIX that aren't obvious what is causing
them, so reverting while I try to figure this out.
2022-10-24 12:20:23 -07:00
Erich Keane
b876f6e2f2 Reapply "GH58368: Correct concept checking in a lambda defined in concept""
This reverts commit 52930162870fee52d0d9c07c5d66e5dce32b08e8.

Now with updating the ASTBitcodes to show that this AST is incompatible
from the last.
2022-10-24 11:46:54 -07:00
Erich Keane
5293016287 Revert "GH58368: Correct concept checking in a lambda defined in concept"
This reverts commit b7c922607c5ba93db8b893d4ba461052af8317b5.

This seems to cause some problems with some modules related things,
which makes me think I should have updated the version-major in
ast-bit-codes?  Going to revert to confirm this was a problem, then
change that and re-try a commit.
2022-10-24 10:21:22 -07:00
Erich Keane
b7c922607c GH58368: Correct concept checking in a lambda defined in concept
As that bug reports, the problem here is that the lambda's
'context-decl' was not set to the concept, and the lambda picked up
template arguments from the concept.  SO, we failed to get the correct
template arguments in SemaTemplateInstantiate.

However, a Concept Specialization is NOT a decl, its an expression, so
we weren't able to put the concept in the decl tree like we needed.
This patch introduces a ConceptSpecializationDecl, which is the smallest
type possible to use for this purpose, containing only the template
arguments.

The net memory impliciation of this is turning a
trailing-objects into a pointer to a type with trailing-objects,  so it
should be minor.

As future work, we may consider giving this type more responsibility, or
figuring out how to better merge duplicates, but as this is just a
template-argument collection at the moment, there isn't much value to
it.

Differential Revision: https://reviews.llvm.org/D136451
2022-10-24 06:32:18 -07:00
Matheus Izvekov
bcd9ba2b7e
[clang] Track the templated entity in type substitution.
This is a change to how we represent type subsitution in the AST.
Instead of only storing the replaced type, we track the templated
entity we are substituting, plus an index.
We modify MLTAL to track the templated entity at each level.

Otherwise, it's much more expensive to go from the template parameter back
to the templated entity, and not possible to do in some cases, as when
we instantiate outer templates, parameters might still reference the
original entity.

This also allows us to very cheaply lookup the templated entity we saw in
the naming context and find the corresponding argument it was replaced
from, such as for implementing template specialization resugaring.

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

Differential Revision: https://reviews.llvm.org/D131858
2022-10-15 22:08:36 +02:00