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
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
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.
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.
lexically contains a mention of the pack.
Systematically distinguish between syntactic and semantic references to
packs, especially when propagating dependence from a type into an
expression. We should consult the type-as-written when computing
syntactic dependence and should consult the semantic type when computing
semantic dependence.
Fixes#54402.
Before this change, CXXDefaultArgExpr would always have
ExprDependence::None. This can lead to issues when, for example, the
inner expression is RecoveryExpr and yet containsErrors() on the default
expression is false.
Differential Revision: https://reviews.llvm.org/D103982
The original version of this was reverted, and @rjmcall provided some
advice to architect a new solution. This is that solution.
This implements a builtin to provide a unique name that is stable across
compilations of this TU for the purposes of implementing the library
component of the unnamed kernel feature of SYCL. It does this by
running the Itanium mangler with a few modifications.
Because it is somewhat common to wrap non-kernel-related lambdas in
macros that aren't present on the device (such as for logging), this
uniquely generates an ID for all lambdas involved in the naming of a
kernel. It uses the lambda-mangling number to do this, except replaces
this with its own number (starting at 10000 for readabililty reasons)
for lambdas used to name a kernel.
Additionally, this implements itself as constexpr with a slight catch:
if a name would be invalidated by the use of this lambda in a later
kernel invocation, it is diagnosed as an error (see the Sema tests).
Differential Revision: https://reviews.llvm.org/D103112
Combined with 'da98651 - Revert "DR2064:
decltype(E) is only a dependent', this change (5a391d3) caused verifier
errors when building Chromium. See https://crbug.com/1168494#c1 for a
reproducer.
Additionally it reverts changes that were dependent on this one, see
below.
> Following up on PR48517, fix handling of template arguments that refer
> to dependent declarations.
>
> Treat an id-expression that names a local variable in a templated
> function as being instantiation-dependent.
>
> This addresses a language defect whereby a reference to a dependent
> declaration can be formed without any construct being value-dependent.
> Fixing that through value-dependence turns out to be problematic, so
> instead this patch takes the approach (proposed on the core reflector)
> of allowing the use of pointers or references to (but not values of)
> dependent declarations inside value-dependent expressions, and instead
> treating template arguments as dependent if they evaluate to a constant
> involving such dependent declarations.
>
> This ends up affecting a bunch of OpenMP tests, due to OpenMP
> imprecisely handling instantiation-dependent constructs, bailing out
> early instead of processing dependent constructs to the extent possible
> when handling the template.
>
> Previously committed as 8c1f2d15b826591cdf6bd6b468b8a7d23377b29e, and
> reverted because a dependency commit was reverted.
This reverts commit 5a391d38ac6c561ba908334d427f26124ed9132e.
It also restores clang/test/SemaCXX/coroutines.cpp to its state before
da986511fb9da1a46a0ca4dba2e49e2426036303.
Revert "[c++20] P1907R1: Support for generalized non-type template arguments of scalar type."
> Previously committed as 9e08e51a20d0d2b1c5724bb17e969d036fced4cd, and
> reverted because a dependency commit was reverted. This incorporates the
> following follow-on commits that were also reverted:
>
> 7e84aa1b81e72d44bcc58ffe1731bfc7abb73ce0 by Simon Pilgrim
> ed13d8c66781b50ff007cb089c5905f9bb9e8af2 by me
> 95c7b6cadbc9a3d4376ef44edbeb3c8bb5b8d7fc by Sam McCall
> 430d5d8429473c2b10b109991d7577a3cea41140 by Dave Zarzycki
This reverts commit 4b574008aef5a7235c1f894ab065fe300d26e786.
Revert "[msabi] Mangle a template argument referring to array-to-pointer decay"
> [msabi] Mangle a template argument referring to array-to-pointer decay
> applied to an array the same as the array itself.
>
> This follows MS ABI, and corrects a regression from the implementation
> of generalized non-type template parameters, where we "forgot" how to
> mangle this case.
This reverts commit 18e093faf726d15f210ab4917142beec51848258.
to dependent declarations.
Treat an id-expression that names a local variable in a templated
function as being instantiation-dependent.
This addresses a language defect whereby a reference to a dependent
declaration can be formed without any construct being value-dependent.
Fixing that through value-dependence turns out to be problematic, so
instead this patch takes the approach (proposed on the core reflector)
of allowing the use of pointers or references to (but not values of)
dependent declarations inside value-dependent expressions, and instead
treating template arguments as dependent if they evaluate to a constant
involving such dependent declarations.
This ends up affecting a bunch of OpenMP tests, due to OpenMP
imprecisely handling instantiation-dependent constructs, bailing out
early instead of processing dependent constructs to the extent possible
when handling the template.
Previously committed as 8c1f2d15b826591cdf6bd6b468b8a7d23377b29e, and
reverted because a dependency commit was reverted.
This reverts commit 8c1f2d15b826591cdf6bd6b468b8a7d23377b29e.
This is part of 5 commits being reverted due to https://crbug.com/1161059. See bug for repro.
to dependent declarations.
Treat an id-expression that names a local variable in a templated
function as being instantiation-dependent.
This addresses a language defect whereby a reference to a dependent
declaration can be formed without any construct being value-dependent.
Fixing that through value-dependence turns out to be problematic, so
instead this patch takes the approach (proposed on the core reflector)
of allowing the use of pointers or references to (but not values of)
dependent declarations inside value-dependent expressions, and instead
treating template arguments as dependent if they evaluate to a constant
involving such dependent declarations.
This ends up affecting a bunch of OpenMP tests, due to OpenMP
imprecisely handling instantiation-dependent constructs, bailing out
early instead of processing dependent constructs to the extent possible
when handling the template.
of type- and value-dependency.
A static data member initialized to a constant inside a class template
is no longer considered value-dependent, per DR1413. A const but not
constexpr variable of literal type (other than integer or enumeration)
is no longer considered value-dependent, per P1815R2.
types.
Previously, a type-dependent cast to a deduced class template
specialization type would end up with a non-dependent class template
specialization type, leading to confusion downstream.
The error-bit was missing, if a DeclRefExpr (which refers to a VarDecl
with a contains-errors initializer).
It could cause different violations in clang -- the DeclRefExpr is value-dependent,
but not contains-errors, `ABC<DeclRefExpr>` could produce a non-error
and non-dependent type in non-template context, which will lead to
crashes in constexpr evaluation.
Reviewed By: sammccall
Differential Revision: https://reviews.llvm.org/D86048
When a semantic checking fails on a syntactic InitListExpr, we will
get an ill-formed semantic InitListExpr (e.g. some inits are nullptr),
using this semantic InitListExpr in clang (without setting the err-bits) is crashy.
Differential Revision: https://reviews.llvm.org/D84140
The expr dependent-bits described that the expression somehow
depends on a template paramter.
With RecoveryExpr, we have generalized it to "the expression depends on
a template parameter, or an error". This patch updates/cleanups all related
comments of dependence-bits.
Differential Revision: https://reviews.llvm.org/D83213
Summary:
We lost errorBit for StmtExpr if a recoveryExpr is the result
expr of a CompoundStmt, which will lead to crashes.
```
// `-StmtExpr
// `-CompoundStmt
// `-RecoveryExp
({ invalid(); });
```
Reviewers: sammccall
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D81154
This patch implements matrix index expressions
(matrix[RowIdx][ColumnIdx]).
It does so by introducing a new MatrixSubscriptExpr(Base, RowIdx, ColumnIdx).
MatrixSubscriptExprs are built in 2 steps in ActOnMatrixSubscriptExpr. First,
if the base of a subscript is of matrix type, we create a incomplete
MatrixSubscriptExpr(base, idx, nullptr). Second, if the base is an incomplete
MatrixSubscriptExpr, we create a complete
MatrixSubscriptExpr(base->getBase(), base->getRowIdx(), idx)
Similar to vector elements, it is not possible to take the address of
a MatrixSubscriptExpr.
For CodeGen, a new MatrixElt type is added to LValue, which is very
similar to VectorElt. The only difference is that we may need to cast
the type of the base from an array to a vector type when accessing it.
Reviewers: rjmccall, anemet, Bigcheese, rsmith, martong
Reviewed By: rjmccall
Differential Revision: https://reviews.llvm.org/D76791
RecoveryExprs are modeled as dependent type to prevent bogus diagnostics
and crashes in clang.
This patch allows to preseve the type for broken calls when the
RecoveryEprs have a known type, e.g. a broken non-overloaded call, a
overloaded call when the all candidates have the same return type, so
that more features (code completion still work on "take2args(x).^") still
work.
However, adding the type is risky, which may result in more clang code being
affected leading to new crashes and hurt diagnostic, and it requires large
effort to minimize the affect (update all sites in clang to handle errorDepend
case), so we add a new flag (off by default) to allow us to develop/test
them incrementally.
This patch also has some trivial fixes to suppress diagnostics (to prevent regressions).
Tested:
all existing tests are passed (when both "-frecovery-ast", "-frecovery-ast-type" flags are flipped on);
Reviewed By: sammccall
Subscribers: rsmith, arphaman, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D79160
Summary:
Added basic representation and parsing/sema handling of array-shaping
operations. Array shaping expression is an expression of form ([s0]..[sn])base,
where s0, ..., sn must be a positive integer, base - a pointer. This
expression is a kind of cast operation that converts pointer expression
into an array-like kind of expression.
Reviewers: rjmccall, rsmith, jdoerfert
Subscribers: guansong, arphaman, cfe-commits, caomhin, kkwli0
Tags: #clang
Differential Revision: https://reviews.llvm.org/D74144
Summary:
This makes it easier/safer to add bits (error) to other node types without
worrying about bit layout all the time.
For now, just use to implement the ad-hoc conversion functions.
Next: remove these functions and use this directly.
Reviewers: hokein
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76939
Normally clang avoids creating expressions when it encounters semantic
errors, even if the parser knows which expression to produce.
This works well for the compiler. However, this is not ideal for
source-level tools that have to deal with broken code, e.g. clangd is
not able to provide navigation features even for names that compiler
knows how to resolve.
The new RecoveryExpr aims to capture the minimal set of information
useful for the tools that need to deal with incorrect code:
source range of the expression being dropped,
subexpressions of the expression.
We aim to make constructing RecoveryExprs as simple as possible to
ensure writing code to avoid dropping expressions is easy.
Producing RecoveryExprs can result in new code paths being taken in the
frontend. In particular, clang can produce some new diagnostics now and
we aim to suppress bogus ones based on Expr::containsErrors.
We deliberately produce RecoveryExprs only in the parser for now to
minimize the code affected by this patch. Producing RecoveryExprs in
Sema potentially allows to preserve more information (e.g. type of an
expression), but also results in more code being affected. E.g.
SFINAE checks will have to take presence of RecoveryExprs into account.
Initial implementation only works in C++ mode, as it relies on compiler
postponing diagnostics on dependent expressions. C and ObjC often do not
do this, so they require more work to make sure we do not produce too
many bogus diagnostics on the new expressions.
See documentation of RecoveryExpr for more details.
original patch from Ilya
This change is based on https://reviews.llvm.org/D61722
Reviewers: sammccall, rsmith
Reviewed By: sammccall, rsmith
Tags: #clang
Differential Revision: https://reviews.llvm.org/D69330
Summary:
The expected pattern is for subclasses to initialize through
computeDependence, which needs only setDependence.
The few places that still use addDependence can be simulated with get+set.
Reviewers: hokein
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76392
The only subexpression that is considered an error now is TypoExpr, but
we plan to add expressions with errors to improve editor tooling on broken
code. We intend to use the same mechanism to guard against spurious
diagnostics on those as well.
See the follow-up revision for an actual usage of the flag.
Original patch from Ilya.
Reviewers: sammccall
Reviewed By: sammccall
Tags: #clang
Differential Revision: https://reviews.llvm.org/D65591
To group the code in one place, simplify it and make it easier to add
the containsErrors bit and find existing bugs.
Reviewers: sammccall
Reviewed By: sammccall
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73638
