A defaulted default constructor for a class X is defined as deleted if [...]
- X is a union and all of its variant members are of const-qualified type.
A pedantic reading therefore says that
union X { };
has a deleted default constructor, which is both silly and almost
certainly unintended. Pretend as if this this read
- X is a union with one or more variant members, and all of its
variant members are of const-qualified type.
llvm-svn: 151394
block pointer that returns a block literal which captures (by copy)
the lambda closure itself. Some aspects of the block literal are left
unspecified, namely the capture variable (which doesn't actually
exist) and the body (which will be filled in by IRgen because it can't
be written as an AST).
Because we're switching to this model, this patch also eliminates
tracking the copy-initialization expression for the block capture of
the conversion function, since that information is now embedded in the
synthesized block literal. -1 side tables FTW.
llvm-svn: 151131
explicit specialization of a function template, mark the instantiation as
constexpr if the specialization is, rather than requiring them to match.
llvm-svn: 151001
We had two separate issues here: firstly, varions functions were assuming that
they did not need to perform semantic checks on trivial destructors (this is
not true in C++11, where a trivial destructor can nonetheless be private or
deleted), and a bunch of DiagnoseUseOfDecl calls were missing for uses of
destructors.
llvm-svn: 150866
decent diagnostics. Finish the work of combining all the 'ShouldDelete'
functions into one. In unifying the code, fix a minor bug where an anonymous
union with a deleted default constructor as a member of a union wasn't being
considered as making the outer union's default constructor deleted.
llvm-svn: 150862
conversion to function pointer. Rather than having IRgen synthesize
the body of this function, we instead introduce a static member
function "__invoke" with the same signature as the lambda's
operator() in the AST. Sema then generates a body for the conversion
to function pointer which simply returns the address of __invoke. This
approach makes it easier to evaluate a call to the conversion function
as a constant, makes the linkage of the __invoke function follow the
normal rules for member functions, and may make life easier down the
road if we ever want to constexpr'ify some of lambdas.
Note that IR generation is responsible for filling in the body of
__invoke (Sema just adds a dummy body), because the body can't
generally be expressed in C++.
Eli, please review!
llvm-svn: 150783
pointers and block pointers). We use dummy definitions to keep the
invariant that an implicit, used definition has a body; IR generation
will substitute the actual contents, since they can't be represented
as C++.
For the block pointer case, compute the copy-initialization needed to
capture the lambda object in the block, which IR generation will need
later.
llvm-svn: 150645
function, provide a specialized diagnostic that indicates the kind of
special member function (default constructor, copy assignment
operator, etc.) and that it was implicitly deleted. Add a hook where
we can provide more detailed information later.
llvm-svn: 150611
lambda expressions. Because these issue was pulled back from Ready
status at the Kona meeting, we still emit an ExtWarn when using
default arguments for lambda expressions.
llvm-svn: 150519
* if, switch, range-based for: warn if semicolon is on the same line.
* for, while: warn if semicolon is on the same line and either next
statement is compound statement or next statement has more
indentation.
Replacing the semicolon with {} or moving the semicolon to the next
line will always silence the warning.
Tests from SemaCXX/if-empty-body.cpp merged into SemaCXX/warn-empty-body.cpp.
llvm-svn: 150515
the instantiation of a constexpr function temploid is now always constexpr, a
defaulted constexpr function temploid is often ill-formed by the rule in
[dcl.fct.def.default]p2 that an explicitly-defaulted constexpr function must
have a constexpr implicit definition. To avoid making loads of completely
reasonable code ill-formed, do not apply that rule to templates.
llvm-svn: 150453
1358, 1360, 1452 and 1453.
- Instantiations of constexpr functions are always constexpr. This removes the
need for separate declaration/definition checking, which is now gone.
- This makes it possible for a constexpr function to be virtual, if they are
only dependently virtual. Virtual calls to such functions are not constant
expressions.
- Likewise, it's now possible for a literal type to have virtual base classes.
A constexpr constructor for such a type cannot actually produce a constant
expression, though, so add a special-case diagnostic for a constructor call
to such a type rather than trying to evaluate it.
- Classes with trivial default constructors (for which value initialization can
produce a fully-initialized value) are considered literal types.
- Classes with volatile members are not literal types.
- constexpr constructors can be members of non-literal types. We do not yet use
static initialization for global objects constructed in this way.
llvm-svn: 150359
instead of having a special-purpose function.
- ActOnCXXDirectInitializer, which was mostly duplication of
AddInitializerToDecl (leading e.g. to PR10620, which Eli fixed a few days
ago), is dropped completely.
- MultiInitializer, which was an ugly hack I added, is dropped again.
- We now have the infrastructure in place to distinguish between
int x = {1};
int x({1});
int x{1};
-- VarDecl now has getInitStyle(), which indicates which of the above was used.
-- CXXConstructExpr now has a flag to indicate that it represents list-
initialization, although this is not yet used.
- InstantiateInitializer was renamed to SubstInitializer and simplified.
- ActOnParenOrParenListExpr has been replaced by ActOnParenListExpr, which
always produces a ParenListExpr. Placed that so far failed to convert that
back to a ParenExpr containing comma operators have been fixed. I'm pretty
sure I could have made a crashing test case before this.
The end result is a (I hope) considerably cleaner design of initializers.
More importantly, the fact that I can now distinguish between the various
initialization kinds means that I can get the tricky generalized initializer
test cases Johannes Schaub supplied to work. (This is not yet done.)
This commit passed self-host, with the resulting compiler passing the tests. I
hope it doesn't break more complicated code. It's a pretty big change, but one
that I feel is necessary.
llvm-svn: 150318
empty union. This still rejects anonymous member structs or unions which only
contain such empty class types, pending standard wording defining exactly what
an empty class type is.
llvm-svn: 150157
the sign bit doesn't have undefined behavior, but a signed left shift of a 1 bit
out of the sign bit still does. As promised to Howard :)
The suppression of the potential constant expression checking in system headers
is also removed, since the problem it was working around is gone.
llvm-svn: 150059
can't produce a constant expression is not ill-formed (so long as some
instantiation of that function can produce a constant expression).
llvm-svn: 149802
value of class type, look for a unique conversion operator converting to
integral or unscoped enumeration type and use that. Implements [expr.const]p5.
Sema::VerifyIntegerConstantExpression now performs the conversion and returns
the converted result. Some important callers of Expr::isIntegralConstantExpr
have been switched over to using it (including all of those required for C++11
conformance); this switch brings a side-benefit of improved diagnostics and, in
several cases, simpler code. However, some language extensions and attributes
have not been moved across and will not perform implicit conversions on
constant expressions of literal class type where an ICE is required.
In passing, fix static_assert to perform a contextual conversion to bool on its
argument.
llvm-svn: 149776
The recent support for potential constant expressions exposed a bug in the
implementation of libstdc++4.6, where numeric_limits<int>::min() is defined
as (int)1 << 31, which isn't a constant expression. Disable the 'constexpr
function never produces a constant expression' error inside system headers
to compensate.
llvm-svn: 149729
function definition can produce a constant expression. This also provides the
last few checks for [dcl.constexpr]p3 and [dcl.constexpr]p4.
llvm-svn: 149108
pointer to incomplete type from an ExtWarn to an error. We put the
ExtWarn in place as part of a workaround for Boost (PR6527), but it
(1) doesn't actually match a GCC extension and (2) has been fixed for
two years in Boost, and (3) causes us to emit code that fails badly at
run time, so it's a bad idea to keep it. Fixes PR11803.
llvm-svn: 148838
This is the last piece of N3031 (decltype in weird places) - supporting
the use of decltype in a class ctor's member-initializer-list to
specify the base classes to initialize.
Reviewed by Richard Smith.
llvm-svn: 148789
Fix some review comments.
Add a test for deduction when std::initializer_list isn't available yet.
Fix redundant error messages. This fixes and outstanding FIXME too.
llvm-svn: 148735
MSVC2010's pair class has a move assignment operator but no explicit copy
constructor, which makes it unusable without this change.
For symmetry, let move copy constructors not mark the default assignment
operator as deleted either. Both changes match cl.exe's behavior. Fixes
pr11826.
Also update the standard excerpt to point to the right paragraph.
llvm-svn: 148675
we have a redeclarable type, and only use the new virtual versions
(getPreviousDeclImpl() and getMostRecentDeclImpl()) when we don't have
that type information. This keeps us from penalizing users with strict
type information (and is the moral equivalent of a "final" method).
Plus, settle on the names getPreviousDecl() and getMostRecentDecl()
throughout.
llvm-svn: 148187
are still added if the cached correction fails validation.
Also fix a copy-and-paste error in a comment from my previous commit.
Finally, add an example of the benefit the typo correction callback adds
to TryNamespaceTypoCorrection--which happens to also tickle the above
caching problem, as the only way a non-namespace Decl would be added to
the possible corrections is if it was cached as the correction for a
previous instance of the same typo where the typo was corrected to a
non-namespace via a different code path.
llvm-svn: 147968
Also includes two examples of the callback: a wrapper/replacement for
the CorrectTypoContext enum, and a conversion of the two calls to
CorrectTypo in SemaDeclCXX.cpp (one of which provides verifiable
improvement to the typo correction, as demonstrated in the added test).
llvm-svn: 147962
- reject definitions of enums within friend declarations
- require 'enum', not 'enum class', for non-declaring references to scoped
enumerations
llvm-svn: 147824
to Redeclarable<NamespaceDecl>, so that we benefit from the improveed
redeclaration deserialization and merging logic provided by
Redeclarable<T>. Otherwise, no functionality change.
As a drive-by fix, collapse the "inline" bit into the low bit of the
original namespace/anonymous namespace, saving 8 bytes per
NamespaceDecl on x86_64.
llvm-svn: 147729
Split out a new ExpressionEvaluationContext flag for this case, and don't treat
it as unevaluated in C++11. This fixes some crash-on-invalids where we would
allow references to class members in potentially-evaluated constant expressions
in static member functions, and also fixes half of PR10177.
The fix to PR10177 exposed a case where template instantiation failed to provide
a source location for a diagnostic, so TreeTransform has been tweaked to supply
source locations when transforming a type. The source location is still not very
good, but MarkDeclarationsReferencedInType would need to operate on a TypeLoc to
improve it further.
Also fix MarkDeclarationReferenced in C++98 mode to trigger instantiation for
static data members of class templates which are used in constant expressions.
This fixes a link-time problem, but we still incorrectly treat the member as
non-constant. The rest of the fix for that issue is blocked on PCH support for
early-instantiated static data members, which will be added in a subsequent
patch.
llvm-svn: 146955
when computing the exception specification of a copy or move constructor,
ignore non-static data member initializers. Fixes PR11418 /
<rdar://problem/10478642>.
llvm-svn: 145269
initializer; all other constexpr variables are merely required to be
initialized. In particular, a user-provided constexpr default constructor can be
used for such initialization.
llvm-svn: 144028
definition, we may not have a scope corresponding to the namespace
where that friend function template actually lives. Work around this
issue by faking up a scope with the appropriate DeclContext.
This is a bit of a hack, but it fixes <rdar://problem/10204947>.
llvm-svn: 143614
wrong class, make sure to drop it immediately; we don't want that
constructor to be available within the DeclContext. Fixes
<rdar://problem/9677163>.
llvm-svn: 143506
that it retains source location information for the type. Aside from
general goodness (being able to walk the types described in that
information), we now have a proper representation for dependent
delegating constructors. Fixes PR10457 (for real).
llvm-svn: 143410
class declaration which forces any such class and any
class that inherits from such a class to have their
typeinfo symbols be marked as weak.
// rdar://10246395
A test/CodeGenCXX/weak-extern-typeinfo.cpp
M lib/Sema/SemaDeclCXX.cpp
M lib/Sema/SemaDeclAttr.cpp
M lib/CodeGen/CGRTTI.cpp
llvm-svn: 142693
shadows a template parameter. Complain about the shadowing (or not,
under -fms-extensions), but don't invalidate the declaration. Merely
forget about the template parameter declaration.
llvm-svn: 142596
actually just has an extraneous 'template<>' header, strip off the
'template<>' header and treat it as a normal friend tag. Fixes PR10660
/ <rdar://problem/9958322>.
llvm-svn: 142587
- Remodel Expr::EvaluateAsInt to behave like the other EvaluateAs* functions,
and add Expr::EvaluateKnownConstInt to capture the current fold-or-assert
behaviour.
- Factor out evaluation of bitfield bit widths.
- Fix a few places which would evaluate an expression twice: once to determine
whether it is a constant expression, then again to get the value.
llvm-svn: 141561
constexpr constructor templates. Such checking is optional, and currently hard
to get right since clang doesn't generate implicit member initializers until
instantiation (even for non-dependent members).
This is needed for clang to accept libstdc++ from g++4.6 in c++0x mode.
llvm-svn: 141547
initializer to update the type of the declaration. For example, this
allows us to determine the size of an incomplete array from its
initializer. Fixes PR10288.
llvm-svn: 141543
Begin with just default constructors. One note is that as a side effect
of this, a conformance test was removed on the basis that this is almost
certainly a defect as with most of union initialization. As it is, clang
does not implement union initialization close to the standard as it's
quite broken as written. I hope to write a paper addressing the issues
eventually.
llvm-svn: 141528
part on patches by Peter Collingbourne.
We diverge from the C++11 standard in a few areas, mostly related to checking
constexpr function declarations, and not just definitions. See WG21 paper
N3308=11-0078 for details.
Function invocation substitution is not available in this patch; constexpr
functions cannot yet be used from within constant expressions.
llvm-svn: 140926
We had an extension which allowed const static class members of floating-point type to have in-class initializers, 'as a C++0x extension'. However, C++0x does not allow this. The extension has been kept, and extended to all literal types in C++0x mode (with a fixit to add the 'constexpr' specifier).
llvm-svn: 140801
the information on to Sema. There's still an incorrectness in the way template instantiation
works now, but that is due to a far larger underlying representational problem.
Also add a test case for various list initialization cases of scalars, which test this
commit as well as the previous one.
llvm-svn: 140460
the key function is inline, rather than the original
declaration. Perhaps FunctionDecl::isInlined() is poorly named. Fixes
<rdar://problem/9979458>.
llvm-svn: 140400
generation when we're dealing with an implicitly-defined copy or move
constructor. And, actually set the implicitly-defined bit for
implicitly-defined constructors and destructors. Should fix self-host.
llvm-svn: 140334
of false positive warnings that depend on noreturn destructors pruning
the CFGs, but only in C++0x mode!
This was really surprising as the debugger quickly reveals that the
attributes are parsed correctly (and using the same code) in both modes.
The warning fires in the same way in both modes. But between parsing and
building the destructor declaration with the noreturn attribute and the
warning, it magically disappears. The key? The 'noexcept' appears!
When we were rebuilding the destructor type with the computed implicit
noexcept we completely dropped the old type on the floor. This almost
makes sense (as the arguments and return type to a destructor aren't
exactly unpredictable), but lost any function type attributes as well.
The fix is simple, we build the new type off of the old one rather than
starting fresh.
Testing this is a bit awkward. I've done it by running the
noreturn-sensitive tests in both modes, which previous failed and now
passes, but if anyone has ideas about how to more specifically and
thoroughly test that the extended info on a destructor is preserved when
adding noexcept, I'm all ears.
llvm-svn: 140138
synthesized move assignment within an implicitly-defined move
assignment operator, be sure to treat the derived-to-base cast as an
xvalue (rather than an lvalue). Otherwise, we'll end up getting the
wrong constructor.
Optimize a direct call to a trivial move assignment operator to an
aggregate copy, as we do for trivial copy assignment operators, and
update the the assertion in CodeGenFunction::EmitAggregateCopy() to
cope with this optimization.
Fixes PR10860.
llvm-svn: 139143
well.
Also, clean up the flow of the code a bit, and factor things more
nicely.
Finally, add the test case that was missing from my previous
commit (sorry), with new tests added to cover temporaries and other fun
cases.
llvm-svn: 139077
reference members of classes. We've had several bugs reported because of
this, and there's no reason not to flag it right away in the compiler.
Comments especially welcome on the strategy for implementing this
warning (IE, what should trigger this?) and on the text of the warning
itself.
I'm going to extend this to cover obvious cases with temporaries and
beef up the test cases some in subsequent patches. I'll then run it over
a large codebase and make sure its not misbehaving before I add it to
-Wall or turn it on by default. I think this one might be a good
candidate for on by default.
llvm-svn: 139075
semantic analysis when taking the address of an xvalue. Instead, just
build the unary operator directly, since it's safe to do so (from the
IRgen and AST perspectives) for any glvalue. Fixes PR10822.
llvm-svn: 138935
collision between C99 hexfloats and C++0x user-defined literals by
giving C99 hexfloats precedence. Also, warning about user-defined
literals that conflict with hexfloats and those that have names that
are reserved by the implementation. Fixes <rdar://problem/9940194>.
llvm-svn: 138839
This makes the code duplication of implicit special member handling even worse,
but the cleanup will have to come later. For now, this works.
Follow-up with tests for explicit defaulting and enabling the __has_feature
flag to come.
llvm-svn: 138821
Example:
template <class T>
class A {
public:
template <class U> void f(U p) { }
template <> void f(int p) { } // <== class scope specialization
};
This extension is necessary to parse MSVC standard C++ headers, MFC and ATL code.
BTW, with this feature in, clang can parse (-fsyntax-only) all the MSVC 2010 standard header files without any error.
llvm-svn: 137573
constructor. Previously, we did some bogus recursion into the fields
of anonymous structs (recursively), which ended up building invalid
ASTs that would cause CodeGen to crash due to invalid GEPs.
Now, we instead build the default initializations based on the
indirect field declarations at the top level, which properly generates
the sequence of GEPs needed to initialize the proper member. Fixes
PR10512 and <rdar://problem/9924046>.
llvm-svn: 137212
completely broken deserialization mapping code we had for VTableUses,
which would have broken horribly as soon as our local-to-global ID
mapping became interesting.
llvm-svn: 136371
FullSourceLoc::getInstantiationLoc to ...::getExpansionLoc. This is part
of the API and documentation update from 'instantiation' as the term for
macros to 'expansion'.
llvm-svn: 135914
Douglas Gregor