forked from OSchip/llvm-project
03282f2fe1
After taking C++98 implicit moves out in D104500,
we put it back in, but now in a new form which preserves
compatibility with pure C++98 programs, while at the same time
giving almost all the goodies from P1825.
* We use the exact same rules as C++20 with regards to which
id-expressions are move eligible. The previous
incarnation would only benefit from the proper subset which is
copy ellidable. This means we can implicit move, in addition:
* Parameters.
* RValue references.
* Exception variables.
* Variables with higher-than-natural required alignment.
* Objects with different type from the function return type.
* We preserve the two-overload resolution, with one small tweak to the
first one: If we either pick a (possibly converting) constructor which
does not take an rvalue reference, or a user conversion operator which
is not ref-qualified, we abort into the second overload resolution.
This gives C++98 almost all the implicit move patterns which we had created test
cases for, while at the same time preserving the meaning of these
three patterns, which are found in pure C++98 programs:
* Classes with both const and non-const copy constructors, but no move
constructors, continue to have their non-const copy constructor
selected.
* We continue to reject as ambiguous the following pattern:
```
struct A { A(B &); };
struct B { operator A(); };
A foo(B x) { return x; }
```
* We continue to pick the copy constructor in the following pattern:
```
class AutoPtrRef { };
struct AutoPtr {
AutoPtr(AutoPtr &);
AutoPtr();
AutoPtr(AutoPtrRef);
operator AutoPtrRef();
};
AutoPtr test_auto_ptr() {
AutoPtr p;
return p;
}
```
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: Quuxplusone
Differential Revision: https://reviews.llvm.org/D105756
|
||
|---|---|---|
| .. | ||
| Inputs | ||
| NSString-type.mm | ||
| abstract-class-type-ivar.mm | ||
| arc-0x.mm | ||
| arc-bool-conversion.mm | ||
| arc-bridged-cast.mm | ||
| arc-libstdcxx.mm | ||
| arc-memfunc.mm | ||
| arc-nsconsumed-errors.mm | ||
| arc-objc-lifetime.mm | ||
| arc-overloading.mm | ||
| arc-ppe.mm | ||
| arc-ptr-comparison.mm | ||
| arc-system-header.mm | ||
| arc-templates.mm | ||
| arc-type-conversion.mm | ||
| arc-type-traits.mm | ||
| arc-unavailable-for-weakref.mm | ||
| arc-unbridged-cast.mm | ||
| argument-dependent-lookup.mm | ||
| attr-swift_name-cxx.mm | ||
| attr-trivial-abi.mm | ||
| base-type-as-written.mm | ||
| block-capture.mm | ||
| block-cleanup.mm | ||
| block-for-lambda-conversion.mm | ||
| block-variable-move.mm | ||
| blocks.mm | ||
| boxing-illegal-types.mm | ||
| bridge-cast-redecl.mm | ||
| builtin-objcsuper.mm | ||
| capturing-flexible-array-in-block.mm | ||
| category-lookup.mm | ||
| class-method-self.mm | ||
| class-templ-error-null-init.mm | ||
| composite-objc-pointertype.mm | ||
| comptypes-1.mm | ||
| comptypes-7.mm | ||
| conditional-expr.mm | ||
| const-cast.mm | ||
| contextual-convert-to-id.mm | ||
| conversion-ranking.mm | ||
| conversion-to-objc-pointer-2.mm | ||
| conversion-to-objc-pointer.mm | ||
| crash.mm | ||
| cstyle-block-pointer-cast.mm | ||
| cstyle-cast.mm | ||
| cxx1y-lambda.mm | ||
| cxxoperator-selector.mm | ||
| debugger-cast-result-to-id.mm | ||
| debugger-support.mm | ||
| decltype.mm | ||
| deduction.mm | ||
| delay-parsing-cfunctions.mm | ||
| delay-parsing-cplusfuncs.mm | ||
| delay-parsing-func-tryblock.mm | ||
| dllexport.mm | ||
| dllimport.mm | ||
| exceptions-fragile.mm | ||
| exceptions.mm | ||
| expr-objcxx.mm | ||
| flexible-array.mm | ||
| foreach-block.mm | ||
| foreach.mm | ||
| format-strings.mm | ||
| fragile-abi-object-assign.m | ||
| function-pointer-void-star.mm | ||
| gc-attributes.mm | ||
| goto.mm | ||
| instancetype.mm | ||
| instantiate-expr.mm | ||
| instantiate-message.mm | ||
| instantiate-method-return.mm | ||
| instantiate-property-access.mm | ||
| instantiate-stmt.mm | ||
| interface-return-type.mm | ||
| is-base-of.mm | ||
| ivar-construct.mm | ||
| ivar-lookup.mm | ||
| ivar-reference-type.mm | ||
| ivar-struct.mm | ||
| linkage-spec.mm | ||
| lit.local.cfg | ||
| literals.mm | ||
| message.mm | ||
| microsoft-abi-byval.mm | ||
| missing-lhs-gun-extension.mm | ||
| namespace-lookup.mm | ||
| no-crash-thread-safety-analysis.mm | ||
| noescape.mm | ||
| null_objc_pointer.mm | ||
| nullability-completeness-cferror.mm | ||
| nullability-consistency-arrays.mm | ||
| nullability-consistency.mm | ||
| nullability-pragmas.mm | ||
| nullptr.mm | ||
| objc-boxed-expressions-nsvalue.mm | ||
| objc-container-subscripting.mm | ||
| objc-decls-inside-namespace.mm | ||
| objc-extern-c.mm | ||
| objc-pointer-conv.mm | ||
| objc-weak-type-traits.mm | ||
| objc-weak.mm | ||
| objc2-merge-gc-attribue-decl.mm | ||
| objcbridge-attribute-arc.mm | ||
| objcbridge-attribute.mm | ||
| objcbridge-related-attribute.mm | ||
| objcbridge-static-cast.mm | ||
| objcxx_openmp.mm | ||
| old-style-cast.mm | ||
| overload-gc.mm | ||
| overload.mm | ||
| parameterized_classes.mm | ||
| parameterized_classes_arc.mm | ||
| parameterized_classes_subst.mm | ||
| parameters.mm | ||
| pointer-to-objc-pointer-conv.mm | ||
| pr32725.mm | ||
| propert-dot-error.mm | ||
| properties.mm | ||
| property-invalid-type.mm | ||
| property-reference.mm | ||
| property-synthesis-error.mm | ||
| property-type-mismatch.mm | ||
| protocol-lookup.mm | ||
| pseudo-destructor.mm | ||
| references.mm | ||
| reinterpret-cast-objc-pointertype.mm | ||
| related-result-type-inference.mm | ||
| reserved-keyword-methods.mm | ||
| sel-address.mm | ||
| standard-conversion-to-bool.mm | ||
| static-cast.mm | ||
| synchronized.mm | ||
| thread-safety-analysis.h | ||
| type-traits-is-pointer.mm | ||
| typeloc-data-alignment.mm | ||
| typo-correction.mm | ||
| unknown-anytype.mm | ||
| vararg-non-pod.mm | ||
| vla.mm | ||
| void_to_obj.mm | ||
| warn-called-once.mm | ||
| warn-implicit-self-in-block.mm | ||
| warn-missing-super.mm | ||
| warn-objc-literal-conversion.mm | ||
| warn-strict-selector-match.mm | ||
| warn-thread-safety-analysis.mm | ||