570 Commits

Author SHA1 Message Date
Vlad Serebrennikov
99e7e7a597 [clang][NFC] Refactor SourceLocExpr::IdentKind
This patch converts `SourceLocExpr::IdentKind` into a scoped enum at namespace scope, making it eligible to be forward-declared. This is needed by `preferred_type` annotations on bit-fields.
2023-11-04 12:43:26 +03:00
Richard Smith
4b163e343c Implement mangling rules for C++20 concepts and requires-expressions.
This implements proposals from:

- https://github.com/itanium-cxx-abi/cxx-abi/issues/24: mangling for
  constraints, requires-clauses, requires-expressions.
- https://github.com/itanium-cxx-abi/cxx-abi/issues/31: requires-clauses and
  template parameters in a lambda expression are mangled into the <lambda-sig>.
- https://github.com/itanium-cxx-abi/cxx-abi/issues/47 (STEP 3): mangling for
  template argument is prefixed by mangling of template parameter declaration
  if it's not "obvious", for example because the template parameter is
  constrained (we already implemented STEP 1 and STEP 2).

This changes the manglings for a few cases:

- Functions and function templates with constraints.
- Function templates with template parameters with deduced types:
  `typename<auto N> void f();`
- Function templates with template template parameters where the argument has a
  different template-head:
  `template<template<typename...T>> void f(); f<std::vector>();`

In each case where a mangling changed, the change fixes a mangling collision.

Note that only function templates are affected, not class templates or variable
templates, and only new constructs (template parameters with deduced types,
constrained templates) and esoteric constructs (templates with template
template parameters with non-matching template template arguments, most of
which Clang still does not accept by default due to
`-frelaxed-template-template-args` not being enabled by default), so the risk
to ABI stability from this change is relatively low. Nonetheless,
`-fclang-abi-compat=17` can be used to restore the old manglings for cases
which we could successfully but incorrectly mangle before.

Fixes #48216, #49884, #61273

Reviewed By: erichkeane, #libc_abi

Differential Revision: https://reviews.llvm.org/D147655
2023-09-20 12:38:15 -07:00
Jens Massberg
c2bf9baf59 Add a concept AST node.
This patch adds a concept AST node (`ConceptLoc`) and uses it at the corresponding places.

There are three objects that might have constraints via concepts:
`TypeConstraint`,  `ConceptSpecializationExpr` and `AutoTypeLoc`.
The first two inherit from `ConceptReference` while the latter has
the information about a possible constraint directly stored in `AutoTypeLocInfo`. It would be nice if the concept information would be stored the same way in all three cases.

Moreover the current structure makes it difficult to deal with these concepts. For example in Clangd accessing the locations of constraints of a `AutoTypeLoc` can only be done with quite ugly hacks.

So we think that it makes sense to create a new AST node for such concepts.

In details we propose the following:
- Rename `ConceptReference` to `ConceptLoc` (or something else what is approriate)
and make it the new AST node.
- `TypeConstraint` and `ConceptSpecializationExpr` do not longer inherit from `ConceptReference` but store a pointer to a `ConceptLoc`.
- `AutoTypeLoc` stores a pointer to `ConceptLoc` instead of storing the concept info in `AutoTypeLocInfo`.

This patch implements a first version of this idea which compiles and where the existing tests pass.
To make this patch as small as possible we keep the existing member functions to access concept data. Later these can be replaced by directly calling the corresponding functions of the `ConceptLoc`s.

Differential Revision: https://reviews.llvm.org/D155858
2023-08-31 10:22:21 +02:00
Fazlay Rabbi
e4c7298bea [OpenMP 5.1] Parsing and Sema support for scope directive
structured-block

where clause is one of the following:

private(list)
reduction([reduction-modifier ,] reduction-identifier : list)
nowait

Differential Revision: https://reviews.llvm.org/D157933
2023-08-24 18:13:52 -07:00
Chi Chun Chen
8ab62da18d [Clang][OpenMP] Support for Code Generation of loop bind clause
Support for Code Generation of "#pragma loop bind" clause.
1) bind(parallel)
2) bind(teams)
3) bind(thread)

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D144634
2023-08-09 14:26:38 -05:00
Nico Weber
5f8d332027 Revert "[Clang][OpenMP] Support for Code Generation of loop bind clause."
This reverts commit 8e7f0320ad7fb760fff598aba4b2c86528c58c2d.
As requested on https://reviews.llvm.org/rG8e7f0320ad7fb760f#1236457
2023-08-08 13:12:25 -04:00
Sunil Kuravinakop
8e7f0320ad [Clang][OpenMP] Support for Code Generation of loop bind clause. 2023-08-08 09:23:00 -05:00
Nico Weber
fab49721b4 Revert "[Clang][OpenMP] Support for Code Generation of loop bind clause"
This reverts commit 4097a24584121dba562d471fab97d3dfec1b5bff.
Breaks tests on macOS, see https://reviews.llvm.org/rG4097a2458412#1235854
2023-08-07 12:01:54 -04:00
Sunil Kuravinakop
4097a24584 [Clang][OpenMP] Support for Code Generation of loop bind clause 2023-08-07 07:58:59 -05:00
Corentin Jabot
4676885270 [clang] Implement P2564 "consteval must propagate up"
Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D151094
2023-06-07 20:45:36 +02:00
Aaron Ballman
12728e1449 [C] Support _Generic expressions with a type operand
_Generic accepts an expression operand whose type is matched against a
list of associations. The expression operand is unevaluated, but the
type matched is the type after lvalue conversion. This conversion loses
type information, which makes it more difficult to match against
qualified or incomplete types.

This extension allows _Generic to accept a type operand instead of an
expression operand. The type operand form does not undergo any
conversions and is matched directly against the association list.

This extension is also supported in C++ as we already supported
_Generic selection expressions there.

The RFC for this extension can be found at:
https://discourse.llvm.org/t/rfc-generic-selection-expression-with-a-type-operand/70388

Differential Revision: https://reviews.llvm.org/D149904
2023-06-05 11:09:58 -04:00
Viktoriia Bakalova
6b50e87f21 [clang] Fix label (de-)serialization in ASM statements.
Differential Revision: https://reviews.llvm.org/D151073
2023-05-22 15:53:45 +00:00
Manna, Soumi
5ebff1ac1b [NFC][Clang] Fix Coverity issues of copy without assign
This patch adds missing copy/move assignment operator to the class which has user-defined copy/move constructor.

Reviewed By: tahonermann

Differential Revision: https://reviews.llvm.org/D149718
2023-05-14 19:49:28 -07:00
Arthur Eubanks
878e590503 Reland [clang] Make predefined expressions string literals under -fms-extensions
MSVC makes these string literals [1][2].

[1] https://godbolt.org/z/6vnTzbExx
[2] https://learn.microsoft.com/en-us/cpp/preprocessor/predefined-macros?view=msvc-170

Fixes #114

Initial commit didn't check if there was a function name when stepping through expressions ignoring parens.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D146764
2023-05-10 10:54:58 -07:00
Arthur Eubanks
ad5bed5372 Revert "[clang] Make predefined expressions string literals under -fms-extensions"
This reverts commit 856f384bf94513c89e754906b7d80fbe5377ab53.

Breaks bots, e.g. https://lab.llvm.org/buildbot/#/builders/123/builds/18775
2023-05-07 16:51:02 -07:00
Arthur Eubanks
856f384bf9 [clang] Make predefined expressions string literals under -fms-extensions
MSVC makes these string literals [1][2].

[1] https://godbolt.org/z/6vnTzbExx
[2] https://learn.microsoft.com/en-us/cpp/preprocessor/predefined-macros?view=msvc-170

Fixes #114

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D146764
2023-05-07 11:27:02 -07:00
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
Aaron Ballman
b0e61de707 Model list initialization more directly; fixes an assert with coverage mapping
Instead of using the validity of a brace's source location as a flag
for list initialization, this now uses a PointerIntPair to model it so
we do not increase the size of the AST node to track this information.
This allows us to retain the valid source location information, which
fixes the coverage assertion.

Fixes https://github.com/llvm/llvm-project/issues/62105
Differential Revision: https://reviews.llvm.org/D148245
2023-04-14 07:19:33 -04:00
Bill Wendling
bfee6f1142 [Clang][NFC] Refactor "Designators" to be more similar
This makes the two interfaces for designators more similar so that it's
easier to merge them together in a future refactoring.

Differential Revision: https://reviews.llvm.org/D147580
2023-04-05 15:46:40 -07:00
Richard Smith
bc73ef0031 PR60985: Fix merging of lambda closure types across modules.
Previously, distinct lambdas would get merged, and multiple definitions
of the same lambda would not get merged, because we attempted to
identify lambdas by their ordinal position within their lexical
DeclContext. This failed for lambdas within namespace-scope variables
and within variable templates, where the lexical position in the context
containing the variable didn't uniquely identify the lambda.

In this patch, we instead identify lambda closure types by index within
their context declaration, which does uniquely identify them in a way
that's consistent across modules.

This change causes a deserialization cycle between the type of a
variable with deduced type and a lambda appearing as the initializer of
the variable -- reading the variable's type requires reading and merging
the lambda, and reading the lambda requires reading and merging the
variable. This is addressed by deferring loading the deduced type of a
variable until after we finish recursive deserialization.

This also exposes a pre-existing subtle issue where loading a
variable declaration would trigger immediate loading of its initializer,
which could recursively refer back to properties of the variable. This
particularly causes problems if the initializer contains a
lambda-expression, but can be problematic in general. That is addressed
by switching to lazily loading the initializers of variables rather than
always loading them with the variable declaration. As well as fixing a
deserialization cycle, that should improve laziness of deserialization
in general.

LambdaDefinitionData had 63 spare bits in it, presumably caused by an
off-by-one-error in some previous change. This change claims 32 of those bits
as a counter for the lambda within its context. We could probably move the
numbering to separate storage, like we do for the device-side mangling number,
to optimize the likely-common case where all three numbers (host-side mangling
number, device-side mangling number, and index within the context declaration)
are zero, but that's not done in this change.

Fixes #60985.

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

Differential Revision: https://reviews.llvm.org/D145737
2023-03-30 14:22:40 -07:00
Kazu Hirata
7eaa7b0553 [clang] Use *{Map,Set}::contains (NFC) 2023-03-15 18:06:34 -07:00
Bill Wendling
554ba99695 Revert "[Clang] Refactor "Designators" into a unified implementation [NFC]"
This reverts commit 3c07db5f58e9852f35202f0fffed50fc7506f37b.

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
Alan Zhao
95a4c0c835 [clang] Reland parenthesized aggregate init patches
This commit relands the patches for implementing P0960R3 and P1975R0,
which describe initializing aggregates via a parenthesized list.

The relanded commits are:

* 40c52159d3ee - P0960R3 and P1975R0: Allow initializing aggregates from
  a parenthesized list of values
* c77a91bb7ba7 - Remove overly restrictive aggregate paren init logic
* 32d7aae04fdb - Fix a clang crash on invalid code in C++20 mode

This patch also fixes a crash in the original implementation.
Previously, if the input tried to call an implicitly deleted copy or
move constructor of a union, we would then try to initialize the union
by initializing it's first element with a reference to a union. This
behavior is incorrect (we should fail to initialize) and if the type of
the first element has a constructor with a single template typename
parameter, then Clang will explode. This patch fixes that issue by
checking that constructor overload resolution did not result in a
deleted function before attempting parenthesized aggregate
initialization.

Additionally, this patch also includes D140159, which contains some
minor fixes made in response to code review comments in the original
implementation that were made after that patch was submitted.

Co-authored-by: Sheng <ox59616e@gmail.com>

Fixes #54040, Fixes #59675

Reviewed By: ilya-biryukov

Differential Revision: https://reviews.llvm.org/D141546
2023-01-12 09:58:15 -08:00
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
Alan Zhao
4e02ff2303 [clang] Revert parentesized aggregate initalization patches
This feature causes clang to crash when compiling Chrome - see
https://crbug.com/1405031 and
https://github.com/llvm/llvm-project/issues/59675

Revert "[clang] Fix a clang crash on invalid code in C++20 mode."

This reverts commit 32d7aae04fdb58e65a952f281ff2f2c3f396d98f.

Revert "[clang] Remove overly restrictive aggregate paren init logic"

This reverts commit c77a91bb7ba793ec3a6a5da3743ed55056291658.

Revert "[clang][C++20] P0960R3 and P1975R0: Allow initializing aggregates from a parenthesized list of values"

This reverts commit 40c52159d3ee337dbed14e4c73b5616ea354c337.
2023-01-04 15:09:36 -08:00
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
Alan Zhao
40c52159d3 [clang][C++20] P0960R3 and P1975R0: Allow initializing aggregates from a parenthesized list of values
This patch implements P0960R3, which allows initialization of aggregates
via parentheses.

As an example:

```
struct S { int i, j; };
S s1(1, 1);

int arr1[2](1, 2);
```

This patch also implements P1975R0, which fixes the wording of P0960R3
for single-argument parenthesized lists so that statements like the
following are allowed:

```
S s2(1);
S s3 = static_cast<S>(1);
S s4 = (S)1;

int (&&arr2)[] = static_cast<int[]>(1);
int (&&arr3)[2] = static_cast<int[2]>(1);
```

This patch was originally authored by @0x59616e and completed by
@ayzhao.

Fixes #54040, Fixes #54041

Co-authored-by: Sheng <ox59616e@gmail.com>

Full write up : https://discourse.llvm.org/t/c-20-rfc-suggestion-desired-regarding-the-implementation-of-p0960r3/63744

Reviewed By: ilya-biryukov

Differential Revision: https://reviews.llvm.org/D129531
2022-12-14 07:54:15 -08:00
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
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
Jennifer Yu
ea64e66f7b [OPENMP]Initial support for error directive.
Differential Revision: https://reviews.llvm.org/D137209
2022-11-02 14:25:28 -07:00
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
Erich Keane
684a78968b Reapply "[Concepts] Recover properly from a RecoveryExpr in a concept"
This reverts commit 192d69f7e65a625e344421841e731e39f80595f5.

This fixes the condition to check whether this is a situation where we
are in a recovery-expr'ed concept a little better, so we don't access an
inactive member of a union, which should make the bots happy.

Differential Revision: https://reviews.llvm.org/D134542
2022-09-26 08:39:10 -07:00
Erich Keane
192d69f7e6 Revert "[Concepts] Recover properly from a RecoveryExpr in a concept"
This reverts commit e3d14bee238b672a7a112311eefee55e142eaefc.

There are apparently a large number of crashes in libcxx and some JSON
Parser thing, so clearly this has some sort of serious issue.  Reverting
so I can take some time to figure out what is going on.
2022-09-26 06:55:25 -07:00
Erich Keane
e3d14bee23 [Concepts] Recover properly from a RecoveryExpr in a concept
Discovered by reducing a different problem, we currently assert because
we failed to make the constraint expressions not dependent, since a
RecoveryExpr cannot be transformed.

This patch fixes that, and gets reasonably nice diagnostics by
introducing a concept (hah!) of "ContainsErrors" to the Satisfaction
types, which causes us to treat the candidate as non-viable.

However, just making THAT candidate non-viable would result in choosing
the 'next best' canddiate, which can result in awkward errors, where we
start evaluating a candidate that is not intended to be selected.
Because of this, and to make diagnostics more relevant, we now just
cause the entire lookup to result in a 'no-viable-candidates'.

This means we will only emit the list of candidates, rather than any
cascading failures.
2022-09-26 06:33:48 -07:00