When a function returns a type and that type was declared [[nodiscard]], we diagnose any unused results from that call as though the function were marked nodiscard. The same behavior should apply to calls through a function pointer.
This addresses PR31526.
llvm-svn: 350317
Implement support for try-catch blocks in constexpr functions, as
proposed in http://wg21.link/P1002 and voted in San Diego for c++20.
The idea is that we can still never throw inside constexpr, so the catch
block is never entered. A try-catch block like this:
try { f(); } catch (...) { }
is then morally equivalent to just
{ f(); }
Same idea should apply for function/constructor try blocks.
rdar://problem/45530773
Differential Revision: https://reviews.llvm.org/D55097
llvm-svn: 348789
in some member function calls.
Specifically, when calling a conversion function, we would fail to
create the AST node representing materialization of the class object.
llvm-svn: 338135
Summary:
As the title says, this makes following code compile:
```
template<typename> struct Foo {};
Foo() -> Foo<void>;
Foo f; // ok
```
Thanks Nicolas Lesser for coining the fix.
Reviewers: rsmith, lichray
Reviewed By: rsmith, lichray
Subscribers: lichray, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D38216
llvm-svn: 328409
The tests that failed on a windows host have been fixed.
Original message:
Start setting dso_local for COFF.
With this there are still some GVs where we don't set dso_local
because setGVProperties is never called. I intend to fix that in
followup commits. This is just the bare minimum to teach
shouldAssumeDSOLocal what it should do for COFF.
llvm-svn: 325940
Summary:
According to the C++11 standard [dcl.type.simple]p4:
The type denoted by decltype(e) is defined as follows:
- if e is an unparenthesized id-expression or an unparenthesized
class member access (5.2.5), decltype(e) is the type of the entity
named by e.
Currently Clang handles the 'member access' case incorrectly for
static data members (decltype returns T& instead of T). This patch
fixes the issue.
Reviewers: faisalv, rsmith, rogfer01
Reviewed By: rogfer01
Subscribers: rogfer01, cfe-commits
Differential Revision: https://reviews.llvm.org/D42969
llvm-svn: 325117
This also clarifies some terminology used by the diagnostic (methods -> Objective-C methods, fields -> non-static data members, etc).
Many of the tests needed to be updated in multiple places for the diagnostic wording tweaks. The first instance of the diagnostic for that attribute is fully specified and subsequent instances cut off the complete list (to make it easier if additional subjects are added in the future for the attribute).
llvm-svn: 319002
Clang makes check for function redefinition after it merged the new
declaration with the existing one. As a result, it produces poor
diagnostics in the case of a friend function defined inline, as in
the code:
```
void func() {}
class C { friend void func() {} };
```
Error message in this case states that `inline declaration of 'func'
follows non-inline definition`, which is misleading, as `func` does
not have explicit `inline` specifier.
With this changes compiler reports function redefinition if the new
function is a friend defined inline and it does not have explicit
`inline` specifier.
Differential Revision: https://reviews.llvm.org/D26065
llvm-svn: 304964
Correct class-template deprecation behavior
Based on the comment in the test, and my reading of the standard, a deprecated warning should be issued in the following case:
template<typename T> [[deprecated]] class Foo{}; Foo<int> f;
This was not the case, because the ClassTemplateSpecializationDecl creation did not also copy the deprecated attribute.
Note: I did NOT audit the complete set of attributes to see WHICH ones should be copied, so instead I simply copy ONLY the deprecated attribute.
Previous DiffRev: https://reviews.llvm.org/D27486, was reverted.
This patch fixes the issues brought up here by the reverter: https://reviews.llvm.org/rL298410
Differential Revision: https://reviews.llvm.org/D31245
llvm-svn: 298634
Based on the comment in the test, and my reading of the standard, a deprecated warning should be issued in the following case:
template<typename T> [[deprecated]] class Foo{}; Foo<int> f;
This was not the case, because the ClassTemplateSpecializationDecl creation did not also copy the deprecated attribute.
Note: I did NOT audit the complete set of attributes to see WHICH ones should be copied, so instead I simply copy ONLY the deprecated attribute.
Differential Revision: https://reviews.llvm.org/D27486
llvm-svn: 298410
It's actually meaningful and useful to allow such variables to have no
initializer, but we are strictly following the standard here until the C++
committee reaches consensus on allowing this.
llvm-svn: 294785
This change adds a new type node, DeducedTemplateSpecializationType, to
represent a type template name that has been used as a type. This is modeled
around AutoType, and shares a common base class for representing a deduced
placeholder type.
We allow deduced class template types in a few more places than the standard
does: in conditions and for-range-declarators, and in new-type-ids. This is
consistent with GCC and with discussion on the core reflector. This patch
does not yet support deduced class template types being named in typename
specifiers.
llvm-svn: 293207
Diasllow a declaration using the 'auto' type specifier from using two different
meanings of it at once, or from declaring multiple functions with deduced
return types or introducing multiple trailing return types.
The standard does not technically disallow the multiple trailing return types
case if all the declarators declare variables (such as function pointers with
trailing return types), but we disallow that too, following the clear intent.
llvm-svn: 291880
The rule we use is that a construction of a class type T from an argument of
type U cannot use an inherited constructor if U is the same as T or is derived
from T (or if the initialization would first convert it to such a type). This
(approximately) matches the rule in use by GCC, and matches the current proposed
DR resolution.
llvm-svn: 291403
* a dependent non-type using-declaration within a function template can be
valid, as it can refer to an enumerator, so don't reject it in the template
definition
* we can partially substitute into a dependent using-declaration if it appears
within a (local class in a) generic lambda within a function template, which
means an UnresolvedUsing*Decl doesn't necessarily instantiate to a UsingDecl.
llvm-svn: 290071
Other compilers accept invalid code here that we reject, and we need a
better error message to try to convince users that the code is really
incorrect. Consider:
class Foo {
typedef MyIterHelper<Foo> iterator;
friend class iterator;
};
Previously our wording was "elaborated type refers to a typedef".
"elaborated type" isn't widely known terminology, so the new diagnostic
says "typedef 'iterator' cannot be referenced with class specifier".
Reviewers: rsmith
Differential Revision: https://reviews.llvm.org/D25216
llvm-svn: 289259
they're redeclarations. This is necessary in order for name lookup to correctly
find the most recent declaration of the name (which affects default template
argument lookup and cross-module merging, among other things).
llvm-svn: 275612
Replace inheriting constructors implementation with new approach, voted into
C++ last year as a DR against C++11.
Instead of synthesizing a set of derived class constructors for each inherited
base class constructor, we make the constructors of the base class visible to
constructor lookup in the derived class, using the normal rules for
using-declarations.
For constructors, UsingShadowDecl now has a ConstructorUsingShadowDecl derived
class that tracks the requisite additional information. We create shadow
constructors (not found by name lookup) in the derived class to model the
actual initialization, and have a new expression node,
CXXInheritedCtorInitExpr, to model the initialization of a base class from such
a constructor. (This initialization is special because it performs real perfect
forwarding of arguments.)
In cases where argument forwarding is not possible (for inalloca calls,
variadic calls, and calls with callee parameter cleanup), the shadow inheriting
constructor is not emitted and instead we directly emit the initialization code
into the caller of the inherited constructor.
Note that this new model is not perfectly compatible with the old model in some
corner cases. In particular:
* if B inherits a private constructor from A, and C uses that constructor to
construct a B, then we previously required that A befriends B and B
befriends C, but the new rules require A to befriend C directly, and
* if a derived class has its own constructors (and so its implicit default
constructor is suppressed), it may still inherit a default constructor from
a base class
llvm-svn: 274049
a base class via a using-declaration. If a class has a using-declaration
declaring either a constructor or an assignment operator, eagerly declare its
special members in case they need to displace a shadow declaration from a
using-declaration.
llvm-svn: 269398
* an unscoped enumerator whose enumeration is a class member is itself a class
member, so can only be the subject of a class-scope using-declaration.
* a scoped enumerator cannot be the subject of a class-scope using-declaration.
llvm-svn: 268594
Fix the issue discovered by fuzzing (PR23057, comment 18) by handling nullptr in Sema::ActOnCXXForRangeDecl
and correct delayed typos in for-range expression before calling Sema::ActOnCXXForRangeStmt. Also fixes PR26288.
Differential Revision: http://reviews.llvm.org/D16630
llvm-svn: 259532
have a nested name specifier. Strictly speaking, forward declarations of class
template partial specializations are not permitted at all, but that seems like
an obvious wording defect, and if we allow them without a nested name specifier
we should also allow them with a nested name specifier.
llvm-svn: 255383
https://gcc.gnu.org/onlinedocs/gcc/Typeof.html
Differences from the GCC extension:
* __auto_type is also permitted in C++ (but only in places where
it could appear in C), allowing its use in headers that might
be shared across C and C++, or used from C++98
* __auto_type can be combined with a declarator, as with C++ auto
(for instance, "__auto_type *p")
* multiple variables can be declared in a single __auto_type
declaration, with the C++ semantics (the deduced type must be
the same in each case)
This patch also adds a missing restriction on applying typeof to
a bit-field, which GCC has historically rejected in C (due to
lack of clarity as to whether the operand should be promoted).
The same restriction also applies to __auto_type in C (in both
GCC and Clang).
This also fixes PR25449.
Patch by Nicholas Allegra!
llvm-svn: 252690
Richard Smith