explicit functions that are not candidates.
It's not always obvious that the reason a conversion was not possible is
because the function you wanted to call is 'explicit', so explicitly say
if that's the case.
It would be nice to rank the explicit candidates higher in the
diagnostic if an implicit conversion sequence exists for their
arguments, but unfortunately we can't determine that without potentially
triggering non-immediate-context errors that we're not permitted to
produce.
Function trailing requires clauses now parsed, supported in overload resolution and when calling, referencing and taking the address of functions or function templates.
Differential Revision: https://reviews.llvm.org/D43357
pack expansion.
Previously, if all parameter / argument pairs for a pack expansion
deduction were non-deduced contexts, we would not deduce the arity of
the pack, and could end up deducing a different arity (leading to
failures during substitution) or defaulting to an arity of 0 (leading to
bad diagnostics about passing the wrong number of arguments to a
variadic function). Instead, we now always deduce the arity for all
involved packs any time we deduce a pack expansion.
This will result in less substitution happening in some cases, which
could avoid non-SFINAEable errors, and should generally improve the
quality of diagnostics when passing initializer lists to variadic
functions.
This reverts commit de21704ba96fa80d3e9402f12c6505917a3885f4.
Regressed/causes this to error due to ambiguity:
void f(const int * const &);
void f(int *);
int main() {
int * x;
f(x);
}
(in case it's important - the original case where this turned up was a
member function overload in a class template with, essentially:
f(const T1&)
f(T2*)
(where T1 == X const *, T2 == X))
It's not super clear to me if this ^ is expected behavior, in which case
I'm sorry about the revert & happy to look into ways to fix the original
code.
The language wording change forgot to update overload resolution to rank
implicit conversion sequences based on qualification conversions in
reference bindings. The anticipated resolution for that oversight is
implemented here -- we order candidates based on qualification
conversion, not only on top-level cv-qualifiers.
For OpenCL/C++, this allows reference binding between pointers with
differing (nested) address spaces. This makes the behavior of reference
binding consistent with that of implicit pointer conversions, as is the
purpose of this change, but that pre-existing behavior for pointer
conversions is itself probably not correct. In any case, it's now
consistently the same behavior and implemented in only one place.
implementing the resolution of CWG2352.
No functionality change, except that we now convert the referent of a
reference binding to the underlying type of the reference in more cases;
we used to happen to preserve the type sugar from the referent if the
only type change was in the cv-qualifiers.
This exposed a bug in how we generate code for trivial assignment
operators: if the type sugar (particularly the may_alias attribute)
got lost during reference binding, we'd use the "wrong" TBAA information
for the load during the assignment.
Summary:
This adds parsing of the qualifiers __ptr32, __ptr64, __sptr, and __uptr and
lowers them to the corresponding address space pointer for 32-bit and 64-bit pointers.
(32/64-bit pointers added in https://reviews.llvm.org/D69639)
A large part of this patch is making these pointers ignore the address space
when doing things like overloading and casting.
https://bugs.llvm.org/show_bug.cgi?id=42359
Reviewers: rnk, rsmith
Subscribers: jholewinski, jvesely, nhaehnle, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D71039
function as referenced, not before.
No functionality change intended. This is groundwork for computing the
exception specification of a defaulted comparison, for which we'd like
to use the implicit body where possible.
Allow sending address spaces into diagnostics to simplify and improve
error reporting. Improved wording of diagnostics for address spaces
in overloading.
Tags: #clang
Differential Revision: https://reviews.llvm.org/D71111
Array members are not yet handled. In addition, defaulted comparisons
can't yet find comparison operators by unqualified lookup (only by
member lookup and ADL). These issues will be fixed in follow-on changes.
Part of the C++20 concepts implementation effort.
- Associated constraints (requires clauses, currently) are now enforced when instantiating/specializing templates and when considering partial specializations and function overloads.
- Elaborated diagnostics give helpful insight as to why the constraints were not satisfied.
Phabricator: D41569
Re-commit, after fixing some memory bugs.
Part of the C++20 concepts implementation effort.
- Associated constraints (requires clauses, currently) are now enforced when instantiating/specializing templates and when considering partial specializations and function overloads.
- Elaborated diagnostics give helpful insight as to why the constraints were not satisfied.
Phabricator: D41569
This fixes an assertion failure in the case where an implicit conversion for a
function call involves an lvalue function conversion, and makes the AST for
initializations involving implicit lvalue function conversions more accurate.
Differential Revision: https://reviews.llvm.org/D66437
llvm-svn: 375313
This adds support for rewriting <, >, <=, and >= to a normal or reversed
call to operator<=>, for rewriting != to a normal or reversed call to
operator==, and for rewriting <=> and == to reversed forms of those same
operators.
Note that this is a breaking change for various C++17 code patterns,
including some in use in LLVM. The most common patterns (where an
operator== becomes ambiguous with a reversed form of itself) are still
accepted under this patch, as an extension (with a warning). I'm hopeful
that we can get the language rules fixed before C++20 ships, and the
extension warning is aimed primarily at providing data to inform that
decision.
llvm-svn: 375306
Summary:
The overload resolution for enums with a fixed underlying type has changed in the C++14 standard. This patch implements the new rule.
Patch by Mark de Wever!
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D65695
llvm-svn: 373866
The static analyzer is warning about potential null dereferences, but in these cases we should be able to use castAs<> directly and if not assert will fire for us.
llvm-svn: 373475
This is groundwork for C++20's P0784R7, where non-trivial destructors
can be constexpr, so we need ExprWithCleanups markers in constant
expressions.
No functionality change intended.
llvm-svn: 372359
- r372318 causes violation of `use-of-uninitialized-value` detected by
MemorySanitizer. Once `Viable` field is set to false, `FailureKind`
needs setting as well as it will be checked during destruction if
`Viable` is not true.
- Revert the part trying to skip `std::vector` erasing.
llvm-svn: 372356
Summary:
- Should consider viable ones only when checking SameSide candidates.
- Replace erasing with clearing viable flag to reduce data
moving/copying.
- Add one and revise another one as the diagnostic message are more
relevant compared to previous one.
Reviewers: tra
Subscribers: cfe-commits, yaxunl
Tags: #clang
Differential Revision: https://reviews.llvm.org/D67730
llvm-svn: 372318
initializers.
This has some interesting interactions with our existing extensions to
support C99 designated initializers as an extension in C++. Those are
resolved as follows:
* We continue to permit the full breadth of C99 designated initializers
in C++, with the exception that we disallow a partial overwrite of an
initializer with a non-trivially-destructible type. (Full overwrite
is OK, because we won't run the first initializer at all.)
* The C99 extensions are disallowed in SFINAE contexts and during
overload resolution, where they could change the meaning of valid
programs.
* C++20 disallows reordering of initializers. We only check for that for
the simple cases that the C++20 rules permit (designators of the form
'.field_name =' and continue to allow reordering in other cases).
It would be nice to improve this behavior in future.
* All C99 designated initializer extensions produce a warning by
default in C++20 mode. People are going to learn the C++ rules based
on what Clang diagnoses, so it's important we diagnose these properly
by default.
* In C++ <= 17, we apply the C++20 rules rather than the C99 rules, and
so still diagnose C99 extensions as described above. We continue to
accept designated C++20-compatible initializers in C++ <= 17 silently
by default (but naturally still reject under -pedantic-errors).
This is not a complete implementation of P0329R4. In particular, that
paper introduces new non-C99-compatible syntax { .field { init } }, and
we do not support that yet.
This is based on a previous patch by Don Hinton, though I've made
substantial changes when addressing the above interactions.
Differential Revision: https://reviews.llvm.org/D59754
llvm-svn: 370544
As discussed in D65249, don't use AlignedCharArray or std::aligned_storage. Just use alignas(X) char Buf[Size];. This will allow me to remove AlignedCharArray entirely, and works on the current minimum version of Visual Studio.
llvm-svn: 367274
Reason: this commit causes crashes in the clang compiler when building
LLVM Support with libc++, see https://bugs.llvm.org/show_bug.cgi?id=42665
for details.
llvm-svn: 366429
Summary:
This patch does mainly three things:
1. It fixes a false positive error detection in Sema that is similar to
D62156. The error happens when explicitly calling an overloaded
destructor for different address spaces.
2. It selects the correct destructor when multiple overloads for
address spaces are available.
3. It inserts the expected address space cast when invoking a
destructor, if needed, and therefore fixes a crash due to the unmet
assertion in llvm::CastInst::Create.
The following is a reproducer of the three issues:
struct MyType {
~MyType() {}
~MyType() __constant {}
};
__constant MyType myGlobal{};
kernel void foo() {
myGlobal.~MyType(); // 1 and 2.
// 1. error: cannot initialize object parameter of type
// '__generic MyType' with an expression of type '__constant MyType'
// 2. error: no matching member function for call to '~MyType'
}
kernel void bar() {
// 3. The implicit call to the destructor crashes due to:
// Assertion `castIsValid(op, S, Ty) && "Invalid cast!"' failed.
// in llvm::CastInst::Create.
MyType myLocal;
}
The added test depends on D62413 and covers a few more things than the
above reproducer.
Subscribers: yaxunl, Anastasia, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D64569
llvm-svn: 366422
If we construct an object in some arbitrary non-default addr space
it should fail unless either:
- There is an implicit conversion from the address space to default
/generic address space.
- There is a matching ctor qualified with an address space that is
either exactly matching or convertible to the address space of an
object.
Differential Revision: https://reviews.llvm.org/D62156
llvm-svn: 363944
Summary:
When using ConstantExpr we often need the result of the expression to be kept in the AST. Currently this is done on a by the node that needs the result and has been done multiple times for enumerator, for constexpr variables... . This patch adds to ConstantExpr the ability to store the result of evaluating the expression. no functional changes expected.
Changes:
- Add trailling object to ConstantExpr that can hold an APValue or an uint64_t. the uint64_t is here because most ConstantExpr yield integral values so there is an optimized layout for integral values.
- Add basic* serialization support for the trailing result.
- Move conversion functions from an enum to a fltSemantics from clang::FloatingLiteral to llvm::APFloatBase. this change is to make it usable for serializing APValues.
- Add basic* Import support for the trailing result.
- ConstantExpr created in CheckConvertedConstantExpression now stores the result in the ConstantExpr Node.
- Adapt AST dump to print the result when present.
basic* : None, Indeterminate, Int, Float, FixedPoint, ComplexInt, ComplexFloat,
the result is not yet used anywhere but for -ast-dump.
Reviewers: rsmith, martong, shafik
Reviewed By: rsmith
Subscribers: rnkovacs, hiraditya, dexonsmith, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D62399
llvm-svn: 363493
Summary:
Constant evaluator does not work on value-dependent or type-dependent
expressions.
Also fixed bugs uncovered by these assertions.
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D61522
llvm-svn: 361050
template name is not visible to unqualified lookup.
In order to support this without a severe degradation in our ability to
diagnose typos in template names, this change significantly restructures
the way we handle template-id-shaped syntax for which lookup of the
template name finds nothing.
Instead of eagerly diagnosing an undeclared template name, we now form a
placeholder template-name representing a name that is known to not find
any templates. When the parser sees such a name, it attempts to
disambiguate whether we have a less-than comparison or a template-id.
Any diagnostics or typo-correction for the name are delayed until its
point of use.
The upshot should be a small improvement of our diagostic quality
overall: we now take more syntactic context into account when trying to
resolve an undeclared identifier on the left hand side of a '<'. In
fact, this works well enough that the backwards-compatible portion (for
an undeclared identifier rather than a lookup that finds functions but
no function templates) is enabled in all language modes.
llvm-svn: 360308
