to use. This makes very little difference right now (other than suppressing
follow-on errors in some cases), but will matter more once we support deduced
return types (we don't want expressions with undeduced return types in the
AST).
llvm-svn: 181107
Instead, we check for one line extern "C" context in linkage computation and
when deciding if a variable is a definition.
This hopefully completes the transition to having "as written" semantics for
hasExternalStorage.
llvm-svn: 180258
statement in constexpr functions. Everything which doesn't require variable
mutation is also allowed as an extension in C++11. 'void' becomes a literal
type to support constexpr functions which return 'void'.
llvm-svn: 180022
C++1y, so stop adding the 'const' there. Provide a compatibility warning for
code relying on this in C++11, with a fix-it hint. Update our lazily-written
tests to add the const, except for those ones which were testing our
implementation of this rule.
llvm-svn: 179969
We were assuming that any expression used as a converted constant
expression would either not have a folded constant value or would be
an integer, which is not the case for some ill-formed constant
expressions. Because converted constant expressions are only used
where integral values are expected, we can simply treat this as an
error path. If that ever changes, we'll need to widen the interface of
Sema::CheckConvertedConstantExpression() anyway.
llvm-svn: 179068
the normal attribute-merging path, because we can't merge alignment attributes
without knowing the complete set of alignment attributes which apply to a
particular declaration.
llvm-svn: 175861
If the member has an initializer, assume it was probably intended to be static
and suggest/recover with that.
If the member doesn't have an initializer, assume it was probably intended to
be const instead of constexpr and suggest that.
(if the attempt to apply these changes fails, don't make any suggestion &
produce the same diagnostic experience as before. The only case where this can
come up that I know of is with a mutable constexpr with an initializer, since
mutable is incompatible with static (but it's already incompatible with
const anyway))
llvm-svn: 173873
This required plumbing through a new flag to determine whether a ParmVarDecl is
actually a parameter of a function declaration (as opposed to a function
typedef etc, where the attribute is prohibited). Weirdly, this attribute (just
like [[noreturn]]) cannot be applied to a function type, just to a function
declaration (and its parameters).
llvm-svn: 173726
it apart from [[gnu::noreturn]] / __attribute__((noreturn)), since their
semantics are not equivalent (for instance, we treat [[gnu::noreturn]] as
affecting the function type, whereas [[noreturn]] does not).
llvm-svn: 172691
a special member" diagnostic from warning to error, and fix the cases where it
produced diagnostics with incorrect wording.
We don't support this as an extension, and we ban it even in C++98 mode. This
breaks too much (for instance, the ABI-specified calling convention for a type
can change if it acquires a copy constructor through the addition of a default
argument).
llvm-svn: 168769
We don't support any C++11 attributes that appertain to declaration specifiers so reject
the attributes in parser until we support them; this also conforms to what g++ 4.8 is doing.
llvm-svn: 167481
This implementation doesn't warn on anything that GCC doesn't warn on with the
exception of templates specializations (GCC doesn't warn, Clang does). The
specific skipped cases (boolean, constant expressions, enums) are open for
debate/adjustment if anyone wants to demonstrate that GCC is being overly
conservative here. The only really obvious false positive I found was in the
Clang regression suite's MPI test - apparently MPI uses specific flag values in
pointer constants. (eg: #define FOO (void*)~0)
llvm-svn: 166039
a non-inline namespace, then reopens it as inline to try to add its symbols to
the surrounding namespace. In this one special case, permit the namespace to be
reopened as inline, and patch up the name lookup tables to match.
llvm-svn: 165263
- General C++11 attributes were previously parsed and ignored. Now they are parsed and stored in AST.
- Add support to parse arguments of attributes that in 'gnu' namespace.
- Differentiate unknown attributes and known attributes that can't be applied to statements when emitting diagnostic.
llvm-svn: 165082
an explicitly-defaulted default constructor would be constexpr. This is
necessary in weird (but well-formed) cases where a class has more than one copy
or move constructor.
Cleanup of now-unused parts of CXXRecordDecl to follow.
llvm-svn: 158289
* In C++11, '[[' is ill-formed unless it starts an attribute-specifier. Reject
array sizes and array indexes which begin with a lambda-expression. Recover by
parsing the lambda as a lambda.
* In Objective-C++11, either '[' could be the start of a message-send.
Fully disambiguate this case: it turns out that the grammars of message-sends,
lambdas and attributes do not actually overlap. Accept any occurrence of '[['
where either '[' starts a message send, but reject a lambda in an array index
just like in C++11 mode.
Implement a couple of changes to the attribute wording which occurred after our
attributes implementation landed:
* In a function-declaration, the attributes go after the exception specification,
not after the right paren.
* A reference type can have attributes applied.
* An 'identifier' in an attribute can also be a keyword. Support for alternative
tokens (iso646 keywords) in attributes to follow.
And some bug fixes:
* Parse attributes after declarator-ids, even if they are not simple identifiers.
* Do not accept attributes after a parenthesized declarator.
* Accept attributes after an array size in a new-type-id.
* Partially disamiguate 'delete' followed by a lambda. More work is required
here for the case where the lambda-introducer is '[]'.
llvm-svn: 154369
a constant expression' error into a DefaultError ExtWarn, so that it can be
disabled and is suppressed in system headers. libstdc++4.7 contains some such
functions which we currently can't evaluate as constant expressions.
llvm-svn: 154115
The deferred lookup table building step couldn't accurately tell which Decls
should be included in the lookup table, and consequently built different tables
in some cases.
Fix this by removing lazy building of DeclContext name lookup tables. In
practice, the laziness was frequently not worthwhile in C++, because we
performed lookup into most DeclContexts. In C, it had a bit more value,
since there is no qualified lookup.
In the place of lazy lookup table building, we simply don't build lookup tables
for function DeclContexts at all. Such name lookup tables are not useful, since
they don't capture the scoping information required to correctly perform name
lookup in a function scope.
The resulting performance delta is within the noise on my testing, but appears
to be a very slight win for C++ and a very slight loss for C. The C performance
can probably be recovered (if it is a measurable problem) by avoiding building
the lookup table for the translation unit.
llvm-svn: 152608
being defined here: [] () -> struct S {} does not define struct S.
In passing, implement DR1318 (syntactic disambiguation of 'final').
llvm-svn: 152551
defined here, but not semantically, so
new struct S {};
is always ill-formed, even if there is a struct S in scope.
We also had a couple of bugs in ParseOptionalTypeSpecifier caused by it being
under-loved (due to it only being used in a few places) so merge it into
ParseDeclarationSpecifiers with a new DeclSpecContext. To avoid regressing, this
required improving ParseDeclarationSpecifiers' diagnostics in some cases. This
also required teaching ParseSpecifierQualifierList about constexpr... which
incidentally fixes an issue where we'd allow the constexpr specifier in other
bad places.
llvm-svn: 152549
function call (or a comma expression with a function call on its right-hand
side), possibly parenthesized, then the return type is not required to be
complete and a temporary is not bound. Other subexpressions inside a decltype
expression do not get this treatment.
This is implemented by deferring the relevant checks for all calls immediately
within a decltype expression, then, when the expression is fully-parsed,
checking the relevant constraints and stripping off any top-level temporary
binding.
Deferring the completion of the return type exposed a bug in overload
resolution where completion of the argument types was not attempted, which
is also fixed by this change.
llvm-svn: 151117
explicit specialization of a function template, mark the instantiation as
constexpr if the specialization is, rather than requiring them to match.
llvm-svn: 151001
* Fix bug when determining whether && / || are potential constant expressions
* Try harder when determining whether ?: is a potential constant expression
* Produce a diagnostic on sizeof(VLA) to provide a better source location
llvm-svn: 150657
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
[dcl.type.simple]p4, which treats all xvalues as returning T&&. We had
previously implemented a pre-standard variant of decltype() that
doesn't cope with, e.g., static_ast<T&&>(e) very well.
llvm-svn: 150348
o Correct the handling of the restrictions on usage of cv-qualified and
ref-qualified function types.
o Fix a bug where such types were rejected in template type parameter default
arguments, due to such arguments not being treated as a template type arg
context.
o Remove the ExtWarn for usage of such types as template arguments; that was
a standard defect, not a GCC extension.
o Improve the wording and unify the code for diagnosing cv-qualifiers with the
code for diagnosing ref-qualifiers.
llvm-svn: 150244
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
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
* support the gcc __builtin_constant_p() ? ... : ... folding hack in C++11
* check for unspecified values in pointer comparisons and pointer subtractions
llvm-svn: 149578
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
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
- If the declarator is at the start of a line, and the previous line contained
another declarator and ended with a comma, then that comma was probably a
typo for a semicolon:
int n = 0, m = 1, l = 2, // k = 5;
myImportantFunctionCall(); // oops!
- If removing the parentheses would correctly initialize the object, then
produce a note suggesting that fix.
- Otherwise, if there is a simple initializer we can suggest which performs
value-initialization, then provide a note suggesting a correction to that
initializer.
Sema::Declarator now tracks the location of the comma prior to the declarator in
the declaration, if there is one, to facilitate providing the note. The code to
determine an appropriate initializer from the -Wuninitialized warning has been
factored out to allow use in both that and -Wvexing-parse.
llvm-svn: 148072
- reject definitions of enums within friend declarations
- require 'enum', not 'enum class', for non-declaring references to scoped
enumerations
llvm-svn: 147824
the Semantic Powers to only warn on class types (or dependent types), where the
constructor or destructor could do something interesting.
llvm-svn: 147642
scope, when no other indication is provided that the user intended to declare a
function rather than a variable.
Remove some false positives from the existing 'parentheses disambiguated as a
function' warning by suppressing it when the declaration is marked as 'typedef'
or 'extern'.
Add a new warning group -Wvexing-parse containing both of these warnings.
The new warning is enabled by default; despite a number of false positives (and
one bug) in clang's test-suite, I have only found genuine bugs with it when
running it over a significant quantity of real C++ code.
llvm-svn: 147599
variable is initialized by a non-constant expression, and pass in the variable
being declared so that earlier-initialized fields' values can be used.
Rearrange VarDecl init evaluation to make this possible, and in so doing fix a
long-standing issue in our C++ constant expression handling, where we would
mishandle cases like:
extern const int a;
const int n = a;
const int a = 5;
int arr[n];
Here, n is not initialized by a constant expression, so can't be used in an ICE,
even though the initialization expression would be an ICE if it appeared later
in the TU. This requires computing whether the initializer is an ICE eagerly,
and saving that information in PCH files.
llvm-svn: 146856
diagnostic message are compared. If either is a substring of the other, then
no error is given. This gives rise to an unexpected case:
// expect-error{{candidate function has different number of parameters}}
will match the following error messages from Clang:
candidate function has different number of parameters (expected 1 but has 2)
candidate function has different number of parameters
It will also match these other error messages:
candidate function
function has different number of parameters
number of parameters
This patch will change so that the verification string must be a substring of
the diagnostic message before accepting. Also, all the failing tests from this
change have been corrected. Some stats from this cleanup:
87 - removed extra spaces around verification strings
70 - wording updates to diagnostics
40 - extra leading or trailing characters (typos, unmatched parens or quotes)
35 - diagnostic level was included (error:, warning:, or note:)
18 - flag name put in the warning (-Wprotocol)
llvm-svn: 146619
or MemberExpr which refers to it. As a side-effect, MemberExprs which refer to
static member functions and static data members are now emitted as constant
expressions.
llvm-svn: 144468
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
We'd also like for "C++11" or "c++11" to be used for the warning
groups, but without removing the old warning flags. Patches welcome;
I've run out of time to work on this today.
llvm-svn: 141801
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
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
cast type has no ownership specified, implicitly "transfer" the ownership of the cast'ed type
to the cast type:
id x;
static_cast<NSString**>(&x); // Casting as (__strong NSString**).
This currently only works for C++ named casts, C casts to follow.
llvm-svn: 134273
storage specifier is different from the storage specifier on the
template. If that storage specifier is the same, then we only warn.
Thanks to John for the prodding.
llvm-svn: 133236
to a warning, since apparently libstdc++'s debug mode does this (and
we can recover safely). Add a Fix-It to insert the "inline", just for kicks.
llvm-svn: 131732
Richard Smith