Commit Graph

2230 Commits

Author SHA1 Message Date
Matheus Izvekov 3ad6dd5d8f [clang] Use decltype((E)) for compound requirement type constraint
See PR45088.

Compound requirement type constraints were using decltype(E) instead of
decltype((E)), as per `[expr.prim.req]p1.3.3`.

Since neither instantiation nor type dependence should matter for
the constraints, this uses an approach where a `decltype` type is not built,
and just the canonical type of the expression after template instantiation
is used on the requirement.

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

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D98160
2021-03-30 22:00:33 +02:00
Marek Kurdej 0620e6f4b7 [clang] [C++2b] [P1102] Accept lambdas without parameter list ().
As an extension, accept such lambdas in previous standards with a warning.

* http://eel.is/c++draft/expr.prim.lambda
* http://wg21.link/P1102

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D98433
2021-03-24 14:42:27 +01:00
Arthur O'Dwyer 5f1de9cab1 [C++20] [P1825] Fix bugs with implicit-move from variables of reference type.
Review D88220 turns out to have some pretty severe bugs, but I *think*
this patch fixes them.

Paper P1825 is supposed to enable implicit move from "non-volatile objects
and rvalue references to non-volatile object types." Instead, what was committed
seems to have enabled implicit move from "non-volatile things of all kinds,
except that if they're rvalue references then they must also refer to non-volatile
things." In other words, D88220 accidentally enabled implicit move from
lvalue object references (super yikes!) and also from non-object references
(such as references to functions).

These two cases are now fixed and regression-tested.

Differential Revision: https://reviews.llvm.org/D98971
2021-03-23 14:12:06 -04:00
Aaron Ballman fa4e72971e Automate common diagnostic checking for statement attributes
Clang currently automates a fair amount of diagnostic checking for
declaration attributes based on the declarations in Attr.td. It checks
for things like subject appertainment, number of arguments, language
options, etc. This patch uses the same machinery to perform diagnostic
checking on statement attributes.
2021-03-19 08:35:38 -04:00
Matheus Izvekov d4a8c7359b [clang] Fix ICE on invalid type parameters for concepts
See PR48593.

Constraints with invalid type parameters were causing a null pointer
dereference.

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

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D98095
2021-03-13 01:23:02 +01:00
Matheus Izvekov c9fd92d573 [clang] Improve diagnostics on implicitly deleted defaulted comparisons
This patch just makes the error message clearer by reinforcing the cause
was a lack of viable **three-way** comparison function for the
**complete object**.

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

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D97990
2021-03-13 01:13:52 +01:00
Nathan James cb559c8d5e
[Sema] Add some basic lambda capture fix-its
Adds fix-its when users forget to explicitly capture variables or this in lambdas

Addresses https://github.com/clangd/clangd/issues/697

Reviewed By: kbobyrev

Differential Revision: https://reviews.llvm.org/D96975
2021-03-11 13:46:25 +00:00
Matheus Izvekov 71e6e82746 [clang] Fix constrained decltype(auto) deduction
Prior to this fix, constrained decltype(auto) behaves exactly the same
as constrained regular auto.
This fixes it so it deduces like decltype(auto).

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

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D98087
2021-03-05 18:20:09 -08:00
Matheus Izvekov 4a8530fc30 [clang] implicitly delete space ship operator with function pointers
See bug #48856

Definitions of classes with member function pointers and default
spaceship operator were getting accepted with no diagnostic on
release build, and triggering assert on builds with runtime checks
enabled. Diagnostics were only produced when actually comparing
instances of such classes.

This patch makes it so Spaceship and Less operators are not considered
as builtin operator candidates for function pointers, producing
equivalent diagnostics for the cases where pointers to member function
and pointers to data members are used instead.

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D95409
2021-02-26 16:03:01 -08:00
Yang Fan fbee4a0c79 [C++20] [P1825] More implicit moves
Implement all of P1825R0:

- implicitly movable entity can be an rvalue reference to non-volatile
    automatic object.
- operand of throw-expression can be a function or catch-clause parameter
    (support for function parameter has already been implemented).
- in the first overload resolution, the selected function no need to be
    a constructor.
- in the first overload resolution, the first parameter of the selected
    function no need to be an rvalue reference to the object's type.

This patch also removes the diagnostic `-Wreturn-std-move-in-c++11`.

Differential Revision: https://reviews.llvm.org/D88220
2021-02-16 17:24:20 -05:00
Richard Smith da986511fb Revert "DR2064: decltype(E) is only a dependent type if E is type-dependent, not
if E is merely instantiation-dependent."

This change leaves us unable to distinguish between different function
templates that differ in only instantiation-dependent ways, for example

template<typename T> decltype(int(T())) f();
template<typename T> decltype(int(T(0))) f();

We'll need substantially better support for types that are
instantiation-dependent but not dependent before we can go ahead with
this change.

This reverts commit e3065ce238.
2021-01-19 12:48:40 -08:00
Richard Smith fbb83f18b5 PR24076, PR33655, C++ CWG 1558: Consider the instantiation-dependence of
the nested-name-specifier when determining whether a qualified type is
instantiation-dependent.

Previously reverted in 25a02c3d1a due to
causing us to reject some code. It turns out that the rejected code was
ill-formed (no diagnostic required).
2021-01-18 21:05:01 -08:00
Richard Smith e3065ce238 DR2064: decltype(E) is only a dependent type if E is type-dependent, not
if E is merely instantiation-dependent.

Previously reverted in 34e72a146111dd986889a0f0ec8767b2ca6b2913;
re-committed with a fix to an issue that caused name mangling to assert.
2021-01-18 21:05:01 -08:00
Richard Smith bc713f6a00 PR48763: Better handling for classes that inherit a default constructor.
The C++ standard wording doesn't appear to properly handle the case
where a class inherits a default constructor from a base class. Various
properties of classes are defined in terms of the corresponding property
of the default constructor, and in this case, the class does not have a
default constructor despite being default-constructible, which the
wording doesn't handle properly.

This change implements a tentative fix for these problems, which has
also been proposed to the C++ committee: if a class would inherit a
default constructor, and does not explicitly declare one, then one is
implicitly declared.
2021-01-18 18:54:04 -08:00
Yang Fan 74f93bc373
[Sema] Fix deleted function problem in implicitly movable test
In implicitly movable test, a two-stage overload resolution is performed.
If the first overload resolution selects a deleted function, Clang directly
performs the second overload resolution, without checking whether the
deleted function matches the additional criteria.

This patch fixes the above problem.

Reviewed By: Quuxplusone

Differential Revision: https://reviews.llvm.org/D92936
2021-01-06 10:05:40 +08:00
Yang Fan e43b3d1f5e
Revert "[Sema] Fix deleted function problem in implicitly movable test"
This reverts commit 89b0972a
2021-01-04 17:21:19 +08:00
Yang Fan 89b0972aa2 [Sema] Fix deleted function problem in implicitly movable test
In implicitly movable test, a two-stage overload resolution is performed.
If the first overload resolution selects a deleted function, Clang directly
performs the second overload resolution, without checking whether the
deleted function matches the additional criteria.

This patch fixes the above problem.

Reviewed By: Quuxplusone

Differential Revision: https://reviews.llvm.org/D92936
2021-01-01 15:47:49 +08:00
Fangrui Song fd739804e0 [test] Add {{.*}} to make ELF tests immune to dso_local/dso_preemptable/(none) differences
For a default visibility external linkage definition, dso_local is set for ELF
-fno-pic/-fpie and COFF and Mach-O. Since default clang -cc1 for ELF is similar
to -fpic ("PIC Level" is not set), this nuance causes unneeded binary format differences.

To make emitted IR similar, ELF -cc1 -fpic will default to -fno-semantic-interposition,
which sets dso_local for default visibility external linkage definitions.

To make this flip smooth and enable future (dso_local as definition default),
this patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `.
2020-12-31 00:27:11 -08:00
Fangrui Song 6b3351792c [test] Add {{.*}} to make tests immune to dso_local/dso_preemptable/(none) differences
For a definition (of most linkage types), dso_local is set for ELF -fno-pic/-fpie
and COFF, but not for Mach-O.  This nuance causes unneeded binary format differences.

This patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `
if there is an explicit linkage.

* Clang will set dso_local for Mach-O, which is currently implied by TargetMachine.cpp. This will make COFF/Mach-O and executable ELF similar.
* Eventually I hope we can make dso_local the textual LLVM IR default (write explicit "dso_preemptable" when applicable) and -fpic ELF will be similar to everything else. This patch helps move toward that goal.
2020-12-30 20:52:01 -08:00
Adrian Kuegel 25a02c3d1a Revert "PR24076, PR33655, C++ CWG 1558: Consider the instantiation-dependence of"
This reverts commit d3bf0bb189.
This causes compilation in certain cases to fail.
Reproducer TBD.
2020-12-23 12:31:52 +01:00
Arthur Eubanks 34e72a1461 Revert "DR2064: decltype(E) is only a dependent type if E is type-dependent, not"
This reverts commit 638867afd4.

This is part of 5 commits being reverted due to https://crbug.com/1161059. See bug for repro.
2020-12-22 10:18:08 -08:00
Richard Smith 638867afd4 DR2064: decltype(E) is only a dependent type if E is type-dependent, not
if E is merely instantiation-dependent.
2020-12-17 23:23:05 -08:00
Richard Smith d3bf0bb189 PR24076, PR33655, C++ CWG 1558: Consider the instantiation-dependence of
the nested-name-specifier when determining whether a qualified type is
instantiation-dependent.
2020-12-17 21:31:23 -08:00
Richard Smith 7e7f38f853 DR1413 and part of P1815R2: Minor improvements to Clang's determination
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.
2020-12-15 14:53:26 -08:00
Richard Smith 6b760a50f5 DR2100: &expr is value-dependent if expr constant-evaluates to a
dependent declaration.
2020-12-15 14:53:26 -08:00
Haojian Wu 6326b09885 [AST][RecoveryExpr] Preserve type for broken overrload member call expr.
Reviewed By: sammccall

Differential Revision: https://reviews.llvm.org/D80109
2020-12-14 08:50:41 +01:00
shafik 6333871f85 Add diagnostic for for-range-declaration being specificed with thread_local
Currently we have a diagnostic that catches the other storage class specifies for the range based for loop declaration but we miss the thread_local case. This changes adds a diagnostic for that case as well.

Differential Revision: https://reviews.llvm.org/D92671
2020-12-04 15:06:35 -08:00
Erik Pilkington 090dd647d9 [Sema] Fold VLAs to constant arrays in a few more contexts
552c6c2 removed support for promoting VLAs to constant arrays when the bounds
isn't an ICE, since this can result in miscompiling a conforming program that
assumes that the array is a VLA. Promoting VLAs for fields is still supported,
since clang doesn't support VLAs in fields, so no conforming program could have
a field VLA.

This change is really disruptive, so this commit carves out two more cases
where we promote VLAs which can't miscompile a conforming program:

 - When the VLA appears in an ivar -- this seems like a corollary to the field thing
 - When the VLA has an initializer -- VLAs can't have an initializer

Differential revision: https://reviews.llvm.org/D90871
2020-12-04 10:03:23 -05:00
Richard Smith c4fb7720ce PR48339: Improve diagnostics for invalid dependent unqualified function calls.
Fix bogus diagnostics that would get confused and think a "no viable
fuctions" case was an "undeclared identifiers" case, resulting in an
incorrect diagnostic preceding the correct one. Use overload resolution
to determine which function we should select when we can find call
candidates from a dependent base class. Make the diagnostics for a call
that could call a function from a dependent base class more specific,
and use a different diagnostic message for the case where the call
target is instead declared later in the same class. Plus some minor
diagnostic wording improvements.
2020-12-02 17:54:55 -08:00
Arthur O'Dwyer e181a6aedd s/instantate/instantiate/ throughout. NFCI.
The static_assert in "libcxx/include/memory" was the main offender here,
but then I figured I might as well `git grep -i instantat` and fix all
the instances I found. One was in user-facing HTML documentation;
the rest were in comments or tests.
2020-12-01 22:13:40 -05:00
Richard Smith 1db60c1307 Remove redundant check for access in the conversion from the naming
class to the declaring class in a class member access.

This check does not appear to be backed by any rule in the standard (the
rule in question was likely removed over the years), and only ever
produces duplicate diagnostics. (It's also not meaningful because there
isn't a unique declaring class after the resolution of core issue 39.)
2020-11-29 19:21:59 -08:00
Richard Smith 7c327db3ef Part of C++ DR 39: a class member lookup is not ambiguous if it finds the
same type in multiple base classes.

Not even if the type is introduced by distinct declarations (for
example, two typedef declarations, or a typedef and a class definition).
2020-11-25 17:03:11 -08:00
Zequan Wu 15a3ae1ab1 [Clang] Add __STDCPP_THREADS__ to standard predefine macros
According to https://eel.is/c++draft/cpp.predefined#2.6, `__STDCPP_THREADS__` is a predefined macro.

Differential Revision: https://reviews.llvm.org/D91747
2020-11-22 16:05:53 -08:00
Aaron Puchert 825f80e111 [Sema] Introduce function reference conversion, NFC
Technically 'noexcept' isn't a qualifier, so this should be a separate conversion.

Also make the test a pure frontend test.

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D67112
2020-11-22 20:51:57 +01:00
Erich Keane a72f11ee20 Fix a pair of tests that would fail on a win32 box
The tests don't specify a triple in some cases, since they shouldn't be
necessary, so I've updated the tests to detect via macro when they are
running on win32 to give the slightly altered diagnostic.
2020-11-17 14:28:52 -08:00
Erich Keane 6976fef05b Update 'note-candiate' functions to skip lambda-conversion-op-overloads
In the wake of https://reviews.llvm.org/D89559, we discovered that a
couple of tests (the ones modified below to have additional triple
versions) would fail on Win32, for 1 of two reasons.  We seem to not
have a win32 buildbot anymore, so the triple is to make sure this
doesn't get broken in the future.

First, two of the three 'note-candidate' functions weren't appropriately
skipping the remaining conversion functions.

Second, in 1 situation (note surrogate candidates) we actually print the
type of the conversion operator.  The two tests that ran into that
needed updating to make sure it printed the proper one in the win32
case.
2020-11-17 05:49:31 -08:00
CJ Johnson 69cd776e1e [CodeGen] Apply 'nonnull' and 'dereferenceable(N)' to 'this' pointer
arguments.

* Adds 'nonnull' and 'dereferenceable(N)' to 'this' pointer arguments
* Gates 'nonnull' on -f(no-)delete-null-pointer-checks
* Introduces this-nonnull.cpp and microsoft-abi-this-nullable.cpp tests to
  explicitly test the behavior of this change
* Refactors hundreds of over-constrained clang tests to permit these
  attributes, where needed
* Updates Clang12 patch notes mentioning this change

Reviewed-by: rsmith, jdoerfert

Differential Revision: https://reviews.llvm.org/D17993
2020-11-16 17:39:17 -08:00
Aaron Puchert dea31f135c Consistent spelling in diagnostics: {l,r}value instead of {l,r}-value
As Richard Smith pointed out in the review of D90123, both the C and C++
standard call it lvalue and rvalue, so let's stick to the same spelling
in Clang.
2020-11-15 18:05:11 +01:00
Aaron Puchert 6f84779674 [Sema] Improve notes for value category mismatch in overloading
When an overloaded member function has a ref-qualifier, like:

class X {
    void f() &&;
    void f(int) &;
};

we would print strange notes when the ref-qualifier doesn't fit the value
category:

X x;
x.f();
X().f(0);

would both print a note "no known conversion from 'X' to 'X' for object
argument" on their relevant overload instead of pointing out the
mismatch in value category.

At first I thought the solution is easy: just use the FailureKind member
of the BadConversionSequence struct. But it turns out that we weren't
properly setting this for function arguments. So I went through
TryReferenceInit to make sure we're doing that right, and found a number
of notes in the existing tests that improved as well.

Fixes PR47791.

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D90123
2020-11-15 18:05:11 +01:00
Richard Smith 5f12f4ff90 Suppress printing of inline namespace names in diagnostics by default,
except where they are necessary to disambiguate the target.

This substantially improves diagnostics from the standard library,
which are otherwise full of `::__1::` noise.
2020-11-11 15:05:51 -08:00
Yang Fan 703038b35a [Sema] Fix volatile check when testing if a return object can be implicitly moved
In C++11 standard, to become implicitly movable, the expression in return
statement should be a non-volatile automatic object. CWG1579 changed the rule
to require that the expression only needs to be an automatic object. C++14
standard and C++17 standard kept this rule unchanged. C++20 standard changed
the rule back to require the expression be a non-volatile automatic object.
This should be a typo in standards, and VD should be non-volatile.

Differential Revision: https://reviews.llvm.org/D88295
2020-11-10 15:11:07 -05:00
Richard Smith 2177e4555a PR47861: Expand dangling reference warning to look through copy
construction, and to assume that assignment operators return *this.
2020-10-30 10:19:50 -07:00
Richard Smith 09abecef7b PR48002: Fix injection of elaborated-type-specifiers within local
classes into the enclosing block scope.

We weren't properly detecting whether the name would be injected into a
block scope in the case where it was lexically declared in a local
class.
2020-10-28 14:29:45 -07:00
Melanie Blower 2e204e2391 [clang] Enable support for #pragma STDC FENV_ACCESS
Reviewers: rjmccall, rsmith, sepavloff

Differential Revision: https://reviews.llvm.org/D87528
2020-10-25 06:46:25 -07:00
Richard Smith f81f09ba89 [c++20] For P0732R2: Support string literal operator templates. 2020-10-25 00:34:15 -07:00
Richard Smith 7b3515880c For P0732R2, P1907R1: ensure that template parameter objects don't refer
to disallowed objects or have non-constant destruction.
2020-10-24 22:11:43 -07:00
Richard Smith cb9b9842d3 PR47954 / DR2126: permit temporary objects that are lifetime-extended by
variables that are usable in constant expressions to themselves be
usable in constant expressions.
2020-10-23 14:29:18 -07:00
Richard Smith e97e9851b2 [c++20] For P0732R2: permit class template argument deduction for non-type template parameters. 2020-10-21 15:03:22 -07:00
Richard Smith caf30e7f03 [c++20] For P0732R2: Give class NTTPs the proper type when examined with 'decltype'.
This requires that we track enough information to determine the original
type of the parameter in a substituted non-type template parameter, to
distinguish the reference-to-class case from the class case.
2020-10-21 14:15:54 -07:00
Richard Smith ba4768c966 [c++20] For P0732R2 / P1907R1: Basic frontend support for class types as
non-type template parameters.

Create a unique TemplateParamObjectDecl instance for each such value,
representing the globally unique template parameter object to which the
template parameter refers.

No IR generation support yet; that will follow in a separate patch.
2020-10-21 13:21:41 -07:00