Commit Graph

1212 Commits

Author SHA1 Message Date
Richard Smith db05f1fb08 PR9546, DR1268: A prvalue cannot be reinterpret_cast to an rvalue reference
type. But a glvalue can be reinterpret_cast to either flavor of reference.

llvm-svn: 155789
2012-04-29 08:24:44 +00:00
Richard Smith 4f402bd985 PR12688: ParseCXXClassMemberDeclaration's sometimes-null ThisDecl takes another
victim. Don't crash if we have a delay-parsed exception specification for a
class member which is invalid in a way which precludes building a FunctionDecl.

llvm-svn: 155788
2012-04-29 07:31:09 +00:00
Richard Smith c5f98f343b [class.copy]p23: Fix an assertion caused by incorrect argument numbering in a
diagnostic, add a test for this paragraph, and tighten up the diagnostic wording
a little.

llvm-svn: 155784
2012-04-29 06:32:34 +00:00
Richard Smith d494c500a0 PR12224 (sort of): Diagnose inheriting constructor declarations in C++11 mode.
We do not support IRGen for these, and get some parts of the semantic analysis
wrong.

llvm-svn: 155728
2012-04-27 19:33:05 +00:00
Richard Smith 6ca73133ca If a type is non-literal by virtue of being incomplete produce notes
explaining that.

llvm-svn: 155598
2012-04-25 23:23:48 +00:00
Richard Smith 1ad04d95bc PR12625: Cope with classes which have incomplete base or member types:
Don't try to query whether an incomplete type has a trivial copy constructor
when determining whether a move constructor should be declared.

llvm-svn: 155575
2012-04-25 18:28:49 +00:00
Richard Smith 2cc2b46683 Don't try to delay parsing the exception specification for a data member of a
class; we would never actually parse it and attach it to the type.

llvm-svn: 155426
2012-04-24 05:48:42 +00:00
Richard Smith 4e42bc8365 PR12629: Cope with parenthesized function types when attaching a delayed
exception specification to a function.

llvm-svn: 155424
2012-04-24 05:06:35 +00:00
Richard Smith 83c478d389 Fix bug where a class's (deleted) copy constructor would be implicitly given a
non-const reference parameter type if the class had any subobjects with deleted
copy constructors. This causes a rejects-valid if the class's copy constructor
is explicitly defaulted (as happens for some implementations of std::pair etc).

llvm-svn: 155218
2012-04-20 18:46:14 +00:00
Richard Smith f623c96260 Implement DR1330 in C++11 mode, to support libstdc++4.7 which uses it.
We have a new flavor of exception specification, EST_Uninstantiated. A function
type with this exception specification carries a pointer to a FunctionDecl, and
the exception specification for that FunctionDecl is instantiated (if needed)
and used in the place of the function type's exception specification.

When a function template declaration with a non-trivial exception specification
is instantiated, the specialization's exception specification is set to this
new 'uninstantiated' kind rather than being instantiated immediately.

Expr::CanThrow has migrated onto Sema, so it can instantiate exception specs
on-demand. Also, any odr-use of a function triggers the instantiation of its
exception specification (the exception specification could be needed by IRGen).
In passing, fix two places where a DeclRefExpr was created but the corresponding
function was not actually marked odr-used. We used to get away with this, but
don't any more.

Also fix a bug where instantiating an exception specification which refers to
function parameters resulted in a crash. We still have the same bug in default
arguments, which I'll be looking into next.

This, plus a tiny patch to fix libstdc++'s common_type, is enough for clang to
parse (and, in very limited testing, support) all of libstdc++4.7's standard
headers.

llvm-svn: 154886
2012-04-17 00:58:00 +00:00
Douglas Gregor 433e05306f Implement the last part of C++ [class.mem]p2, delaying the parsing of
exception specifications on member functions until after the closing
'}' for the containing class. This allows, for example, a member
function to throw an instance of its own class. Fixes PR12564 and a
fairly embarassing oversight in our C++98/03 support.

llvm-svn: 154844
2012-04-16 18:27:27 +00:00
Douglas Gregor 3024f07c12 Implement C++11 [expr.prim.general]p3, which permits the use of 'this'
in the declaration of a non-static member function after the
(optional) cv-qualifier-seq, which in practice means in the exception
specification and late-specified return type. 

The new scheme here used to manage 'this' outside of a member function
scope is more general than the Scope-based mechanism previously used
for non-static data member initializers and late-parsesd attributes,
because it can also handle the cv-qualifiers on the member
function. Note, however, that a separate pass is required for static
member functions to determine whether 'this' was used, because we
might not know that we have a static function until after declaration
matching.

Finally, this introduces name mangling for 'this' and for the implicit
'this', which is intended to match GCC's mangling. Independent
verification for the new mangling test case would be appreciated.

Fixes PR10036 and PR12450.

llvm-svn: 154799
2012-04-16 07:05:22 +00:00
Richard Smith 822698412b PR12500: Improve the wording of the diagnostic for a redefinition of a name
in the wrong namespace scope. Patch by Jonathan Sauer!

llvm-svn: 154656
2012-04-13 04:07:40 +00:00
Douglas Gregor 350880c4d8 Improve diagnostics in C++11 when a non-type template argument for a
non-type template parameter of pointer type is not a constant expression.

llvm-svn: 154424
2012-04-10 19:03:30 +00:00
Douglas Gregor 20fdef32dd Rework implementation of null non-type template arguments based on
Richard's feedback, to properly catch non-constant expressions and
type mismatches. Finishes <rdar://problem/11193097>.

llvm-svn: 154407
2012-04-10 17:08:25 +00:00
Richard Smith 7bdcc4a9da Disambiguation of '[[':
* 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
2012-04-10 01:32:12 +00:00
John McCall dd1eca34b5 My original patch missed the virtual-base case for destroying
base-class subojects.

Incidentally, thinking about virtual bases makes it clear to me that
we're not appropriately computing the access to the virtual base's
member because we're not computing the best possible access to the
virtual base at all;  in fact, we're basically assuming it's public.
I'll file a separate PR about that.

llvm-svn: 154346
2012-04-09 21:51:56 +00:00
John McCall d42742143c Fix the access check performed as part of the determination of whether
to define a special member function as deleted so that it properly
establishes an object context for the accesses to the base subobject
members.

llvm-svn: 154343
2012-04-09 20:53:23 +00:00
John McCall 5dadb65e07 Fix several problems with protected access control:
- The [class.protected] restriction is non-trivial for any instance
    member, even if the access lacks an object (for example, if it's
    a pointer-to-member constant).  In this case, it is equivalent to
    requiring the naming class to equal the context class.
  - The [class.protected] restriction applies to accesses to constructors
    and destructors.  A protected constructor or destructor can only be
    used to create or destroy a base subobject, as a direct result.
  - Several places were dropping or misapplying object information.

The standard could really be much clearer about what the object type is
supposed to be in some of these accesses.  Usually it's easy enough to
find a reasonable answer, but still, the standard makes a very confident
statement about accesses to instance members only being possible in
either pointer-to-member literals or member access expressions, which
just completely ignores concepts like constructor and destructor
calls, using declarations, unevaluated field references, etc.

llvm-svn: 154248
2012-04-07 03:04:20 +00:00
Douglas Gregor 31f55dced5 Implement support for null non-type template arguments for non-type
template parameters of pointer, pointer-to-member, or nullptr_t
type in C++11. Fixes PR9700 / <rdar://problem/11193097>.

llvm-svn: 154219
2012-04-06 22:40:38 +00:00
Richard Smith d8b8effa6e Temporary workaround for bug#12457: turn the 'constexpr function never produces
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
2012-04-05 18:57:10 +00:00
Richard Smith fa0a1f531f Improve diagnostics for invalid use of non-static members / this:
* s/nonstatic/non-static/ in the diagnostics, since the latter form outvoted
  the former by 28-2 in our diagnostics.
* Fix the "use of member in static member function" diagnostic to correctly
  detect this situation inside a block or lambda.
* Produce a more specific "invalid use of non-static member" diagnostic for
  the case where a nested class member refers to a member of a
  lexically-surrounding class.

llvm-svn: 154073
2012-04-05 01:13:04 +00:00
David Blaikie 09ffc9b473 Enable warn_impcast_literal_float_to_integer by default.
This diagnostic seems to be production ready, it's just an oversight that it
wasn't turned on by default.

The test changes are a bit of a mixed bag. Some tests that seemed like they
clearly didn't need to use this behavior have been modified not to use it.
Others that I couldn't be sure about, I added the necessary expected-warnings
to.

It's possible the diagnostic message could be improved to make it clearer that
this warning can be suppressed by using a value that won't lose precision when
converted to the target type (but can still be a floating point literal, such
as "bool b = 1.0;").

llvm-svn: 154068
2012-04-05 00:16:44 +00:00
Richard Smith 60f4f86a79 Hardcode a triple to prevent the test failing on targets which don't support __thread.
llvm-svn: 154058
2012-04-04 21:54:03 +00:00
Richard Smith 9380e0ea23 Implement C++11 [temp.arg.nontype]'s permission to use the address of an object
or function with internal linkage as a non-type template argument.

llvm-svn: 154053
2012-04-04 21:11:30 +00:00
Douglas Gregor bf13895a4b Dependent-sequence initialization of a single element can be direct
list-initialization. Loosen an over-eager assertion to fix PR12453.

llvm-svn: 153995
2012-04-04 04:06:51 +00:00
John McCall b73bc9af60 When computing the conversion sequence in overload resolution
for converting an empty list to a scalar, be sure to initialize
the source and destination types so that comparison of conversion
sequences will work in case there are multiple viable candidates.

llvm-svn: 153993
2012-04-04 02:40:27 +00:00
Richard Smith f989e51cb6 PR10217 diagnostic fix: don't say 'copy constructor' when we mean
'copy assignment operator'.

llvm-svn: 153897
2012-04-02 21:07:48 +00:00
Richard Smith 6f1e2c6d19 Finish PR10217: Ensure we say that a special member was implicitly, not
explicitly, deleted in all relevant cases, and explain why.

llvm-svn: 153894
2012-04-02 20:59:25 +00:00
Richard Smith cf8ec8dad6 Implement DR1402: if a field or base class is not movable, the derived class's
move constructor/move assignment operator are not declared, rather than being
defined as deleted, so move operations on the derived class fall back to
copying rather than moving.

If a move operation on the derived class is explicitly defaulted, the
unmovable subobject will be copied instead of being moved.

llvm-svn: 153883
2012-04-02 18:40:40 +00:00
Richard Smith 23d55873cb Basic semantic analysis support for inheriting constructor declarations in
dependent contexts.

llvm-svn: 153858
2012-04-02 01:30:27 +00:00
Richard Smith 852265ff1c PR10217: Provide diagnostics explaining why an implicitly-deleted special
member function is deleted.

llvm-svn: 153773
2012-03-30 20:53:28 +00:00
Eli Friedman 2b22a6e61c Extend -Wc++11-narrowing to cover converted constant expressions as well as braced-initializers. <rdar://problem/11121178>.
llvm-svn: 153703
2012-03-29 23:39:39 +00:00
Douglas Gregor b7d17ddbf9 Unify and fix our checking of C++ [dcl.meaning]p1's requirements
concerning qualified declarator-ids. We now diagnose extraneous
qualification at namespace scope (which we had previously missed) and
diagnose these qualification errors for all kinds of declarations; it
was rather uneven before. Fixes <rdar://problem/11135644>.

llvm-svn: 153577
2012-03-28 16:01:27 +00:00
Richard Smith 7d137e3b98 Support for definitions of member enumerations of class templates outside the
class template's definition, and for explicit specializations of such enum
members.

llvm-svn: 153304
2012-03-23 03:33:32 +00:00
Douglas Gregor 31feb337a6 Diagnose tag and class template declarations with qualified
declarator-ids that occur at class scope. Fixes PR8019.

llvm-svn: 153002
2012-03-17 23:06:31 +00:00
David Blaikie aeef2ae8f9 Unpluralize -Wfoo-conversions warnings for consistency.
Err on the side of brevity and rename (while providing aliases for the original
name) -Wbool-conversions, -Wint-conversions, and -Wvector-conversions for
consistency with constant, literal, string, and sign conversion warnings. And
name the diagnostic groups explicitly while I'm here rather than rewriting the
string in the groups and sema td files.

Curiously, vector-conversion is not under -Wconversion. Perhaps it should be.

llvm-svn: 152776
2012-03-15 05:09:31 +00:00
Richard Smith 4b38ded66a Instantiating a class template should not instantiate the definition of any
scoped enumeration members. Later uses of an enumeration temploid as a nested
name specifier should cause its instantiation. Plus some groundwork for
explicit specialization of member enumerations of class templates.

llvm-svn: 152750
2012-03-14 23:13:10 +00:00
Richard Smith d0e1c95dcc Implement [temp.param]p5: the top-level cv-qualifiers on a non-type template
parameter's declaration are ignored when determining the parameter's type.

llvm-svn: 152619
2012-03-13 07:21:50 +00:00
Richard Smith 9479a2e35e PR11850 + duplicates: don't assume that a function parameter pack expansion is
at the end of the parameter list.

llvm-svn: 152618
2012-03-13 06:56:52 +00:00
Richard Smith 05afe5e084 Fix PR10447: lazily building name lookup tables for DeclContexts was broken.
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
2012-03-13 03:12:56 +00:00
Douglas Gregor 8409ccd8f6 C++11 [temp.deduct.call]p6 tweak: when given a set of overlaoded
functions that includes an explicit template argument list, perform
an inner deduction against each of the function templates in that list
and, if successful, use the result of that deduction for the outer
template argument deduction. Fixes PR11713.

llvm-svn: 152575
2012-03-12 21:09:16 +00:00
Richard Smith bfdb108fc5 Fix parsing of trailing-return-type. Types are syntactically prohibited from
being defined here: [] () -> struct S {} does not define struct S.

In passing, implement DR1318 (syntactic disambiguation of 'final').

llvm-svn: 152551
2012-03-12 08:56:40 +00:00
Richard Smith c5b0552055 Fix parsing of type-specifier-seq's. Types are syntactically allowed to be
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
2012-03-12 07:56:15 +00:00
Douglas Gregor 194ea69d62 When template argument deduction is ignoring qualifiers, perform deep
structural comparison of non-dependent types. Otherwise, we end up
rejecting cases where the non-dependent types don't match due to
qualifiers in, e.g., a pointee type. Fixes PR12132.

llvm-svn: 152529
2012-03-11 03:29:50 +00:00
Douglas Gregor 50a3cdddda When determining whether an identifier followed by a '<' in a member
access expression is the start of a template-id, ignore function
templates found in the context of the entire postfix-expression. Fixes
PR11856.

llvm-svn: 152520
2012-03-10 23:52:41 +00:00
David Blaikie 631a486e6a Fix crash & accepts-invalid for array of arrays of user defined type.
Test case/other help by Richard Smith.
Code review by John McCall.

llvm-svn: 152519
2012-03-10 23:40:02 +00:00
Richard Smith 5731c75414 PR12225: The requirement that literal operators be namespace-scope functions
does not imply that such functions can't be declared at block scope.

llvm-svn: 152509
2012-03-10 22:18:57 +00:00
Richard Smith 2a70e65436 Improve diagnostics for UCNs referring to control characters and members of the
basic source character set in C++98. Add -Wc++98-compat diagnostics for same in
literals in C++11. Extend such support to cover string literals as well as
character literals, and mark N2170 as done.

This seems too minor to warrant a release note to me. Let me know if you disagree.

llvm-svn: 152444
2012-03-09 22:27:51 +00:00
Benjamin Kramer 1f5568c55f Harden test for 32 bit platforms, where size_t is unsigned int (not unsigned long).
llvm-svn: 152404
2012-03-09 13:17:27 +00:00
Richard Smith c1b0565a26 Literal operator suffixes and regular names live in separate namespaces.
llvm-svn: 152395
2012-03-09 08:37:16 +00:00
Richard Smith 768ceccc75 Literal operators can't have default arguments.
llvm-svn: 152394
2012-03-09 08:16:22 +00:00
Richard Smith bcc22fc4e1 Support for raw and template forms of numeric user-defined literals,
and lots of tidying up.

llvm-svn: 152392
2012-03-09 08:00:36 +00:00
Richard Smith bf79fc49b3 Remove a test FIXME for a case which is already fixed.
llvm-svn: 152349
2012-03-08 23:08:29 +00:00
Richard Smith 0df56f4a90 Implement C++11 [lex.ext]p10 for string and character literals: a ud-suffix not
starting with an underscore is ill-formed.

Since this rule rejects programs that were using <inttypes.h>'s macros, recover
from this error by treating the ud-suffix as a separate preprocessing-token,
with a DefaultError ExtWarn. The approach of treating such cases as two tokens
is under discussion for standardization, but is in any case a conforming
extension and allows existing codebases to keep building while the committee
makes up its mind.

Reword the warning on the definition of literal operators not starting with
underscores (which are, strangely, legal) to more explicitly state that such
operators can't be called by literals. Remove the special-case diagnostic for
hexfloats, since it was both triggering in the wrong cases and incorrect.

llvm-svn: 152287
2012-03-08 02:39:21 +00:00
Richard Smith c67fdd4eb9 AST representation for user-defined literals, plus just enough of semantic
analysis to make the AST representation testable. They are represented by a
new UserDefinedLiteral AST node, which is a sugared CallExpr. All semantic
properties, including full CodeGen support, are achieved for free by this
representation.

UserDefinedLiterals can never be dependent, so no custom instantiation
behavior is required. They are mangled as if they were direct calls to the
underlying literal operator. This matches g++'s apparent behavior (but not its
actual mangling, which is broken for literal-operator-ids).

User-defined *string* literals are now fully-operational, but the semantic
analysis is quite hacky and needs more work. No other forms of user-defined
literal are created yet, but the AST support for them is present.

This patch committed after midnight because we had already hit the quota for
new kinds of literal yesterday.

llvm-svn: 152211
2012-03-07 08:35:16 +00:00
Richard Smith d67aea28f6 User-defined literals: reject string and character UDLs in all places where the
grammar requires a string-literal and not a user-defined-string-literal. The
two constructs are still represented by the same TokenKind, in order to prevent
a combinatorial explosion of different kinds of token. A flag on Token tracks
whether a ud-suffix is present, in order to prevent clients from needing to look
at the token's spelling.

llvm-svn: 152098
2012-03-06 03:21:47 +00:00
Richard Smith f506eaf36d static_assert: Allow any string-literal as the message, not just a character
string literal, and adjust the diagnostic code to match. This also causes us
to escape any control characters in the message.

llvm-svn: 152069
2012-03-05 23:20:05 +00:00
Richard Smith 2a1b1c68f3 More tests for r152012.
llvm-svn: 152013
2012-03-05 04:06:25 +00:00
Richard Smith e18f0faff2 Lexing support for user-defined literals. Currently these lex as the same token
kinds as the underlying string literals, and we silently drop the ud-suffix;
those issues will be fixed by subsequent patches.

llvm-svn: 152012
2012-03-05 04:02:15 +00:00
Richard Smith 72eebee0cb Add tests for [over.literal]. Fix a few bugs which were exposed by the tests.
llvm-svn: 151997
2012-03-04 09:41:16 +00:00
Richard Smith 522fa53703 Add a pile of tests for unrestricted unions, and advertise support for them.
llvm-svn: 151992
2012-03-03 23:51:05 +00:00
Richard Smith 35ecb36fcd Ensure that we instantiate static reference data members of class templates
early, since their values can be used in constant expressions in C++11. For
odr-use checking, the opposite change is required, since references are
odr-used whether or not they satisfy the requirements for appearing in a
constant expression.

llvm-svn: 151881
2012-03-02 04:14:40 +00:00
Richard Smith 5e0cac784a Reject 'a = {0} = {0}' rather than parsing it as '(a = {0}) = {0}'. Also
improve the diagnostics for some attempts to use initializer lists in
expressions.

llvm-svn: 151794
2012-03-01 02:59:17 +00:00
Eli Friedman c6237c6e05 Make the odr-use logic work correctly for constant-expressions. PR12006.
llvm-svn: 151699
2012-02-29 03:16:56 +00:00
Sebastian Redl 6776673f09 Convert initializer lists to temporaries in CreateBuiltinBinOp. Allows assignment of init lists to built-in types and resolves PR12088.
llvm-svn: 151551
2012-02-27 20:34:02 +00:00
Richard Smith 619ecdc80f Ensure that we delete default constructors in the right cases. Don't delete the
default constructor of a union if it has a const member with no user-provided
default constructor.

llvm-svn: 151516
2012-02-27 06:07:25 +00:00
Richard Smith 2fbb3d84a2 Tests for r151508.
llvm-svn: 151509
2012-02-26 23:49:01 +00:00
Richard Smith 8e1c932ffb Don't assert when trying to diagnose why a class with a constructor template is
non-trivial.

llvm-svn: 151486
2012-02-26 10:50:32 +00:00
Richard Smith 921bd20ddd Ensure that we delete destructors in the right cases. Specifically:
- variant members with nontrivial destructors make the containing class's
   destructor deleted
 - check for a virtual destructor after checking for overridden methods in the
   base class(es)
 - check for an inaccessible operator delete for a class with a virtual
   destructor.

Do not try to call an anonymous union field's destructor from the destructor of
the containing class.

llvm-svn: 151483
2012-02-26 09:11:52 +00:00
Richard Smith 0d1f3cb1b5 Special members which are defaulted or deleted on their first declaration are
trivial if the implicit declaration would be. Don't forget to set the Trivial
flag on the special member as well as on the class. It doesn't seem ideal that
we have two separate mechanisms for storing this information, but this patch
does not attempt to address that.

This leaves us in an interesting position where the has_trivial_X trait for a
class says 'yes' for a deleted but trivial X, but is_trivially_Xable says 'no'.
This seems to be what the standard requires.

llvm-svn: 151465
2012-02-26 00:31:33 +00:00
Richard Smith eae99680e3 PR11956: C++11's special exception for accessing non-static data members from
unevaluated operands applies within member functions, too.

llvm-svn: 151443
2012-02-25 10:04:07 +00:00
Douglas Gregor f8ab049f17 Add test for C++ DR899.
llvm-svn: 151411
2012-02-24 23:57:42 +00:00
Douglas Gregor 6073dcab38 Implement C++11 [over.match.copy]p1b2, which allows the use of
explicit conversion functions to initialize the argument to a
copy/move constructor that itself is the subject of direct
initialization. Since we don't have that much context in overload
resolution, we end up threading more flags :(.

Fixes <rdar://problem/10903741> / PR10456. 

llvm-svn: 151409
2012-02-24 23:56:31 +00:00
Douglas Gregor 2837aa2932 Teach overload resolution to prefer user-defined conversion via a
lambda closure type's function pointer conversion over user-defined
conversion via a lambda closure type's block pointer conversion,
always. This is a preference for more-standard code (since blocks
are an extension)  and a nod to efficiency, since function pointers
don't require any memory management. Fixes PR12063.

llvm-svn: 151170
2012-02-22 17:32:19 +00:00
Richard Smith 2a15b74605 Accept braced-init-lists in conditions, and, in passing, dramatically improve
the diagnostic for using a parenthesized direct-initializer in a condition.

llvm-svn: 151137
2012-02-22 06:49:09 +00:00
Douglas Gregor ed90df3800 Generate an AST for the conversion from a lambda closure type to a
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
2012-02-22 05:02:47 +00:00
Eli Friedman 7cd4a9ba48 Improve diagnostics a bit for bad member initializers, and fix an obscure bug involving packs. Fixes PR12049.
llvm-svn: 151130
2012-02-22 04:49:04 +00:00
Richard Smith fd555f6b1f Implement C++11 [expr.call]p11: If the operand to a decltype-specifier is a
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
2012-02-22 02:04:18 +00:00
Douglas Gregor b8389976b2 In the conflict between C++11 [expr.prim.general]p4, which declares
that 'this' can be used in the brace-or-equal-initializer of a
non-static data member, and C++11 [expr.prim.lambda]p9, which says
that lambda expressions not in block scope can have no captures, side
fully with C++11 [expr.prim.general]p4 by allowing 'this' to be
captured within these initializers. This seems to be the intent of
non-static data member initializers.

llvm-svn: 151101
2012-02-21 22:51:27 +00:00
Douglas Gregor 680e9e018d Improve our handling of lambda expressions that occur within default
arguments. There are two aspects to this:

  - Make sure that when marking the declarations referenced in a
  default argument, we don't try to mark local variables, both because
  it's a waste of time and because the semantics are wrong: we're not
  in a place where we could capture these variables again even if it
  did make sense.
  - When a lambda expression occurs in a default argument of a
  function template, make sure that the corresponding closure type is
  considered dependent, so that it will get properly instantiated. The
  second bit is a bit of a hack; to fix it properly, we may have to
  rearchitect our handling of default arguments, parsing them only
  after creating the function definition. However, I'd like to
  separate that work from the lambdas work.

llvm-svn: 151076
2012-02-21 19:11:17 +00:00
Eli Friedman 932b0b1a13 Make RequireLiteralType work correctly with incomplete array types. PR12037.
llvm-svn: 151005
2012-02-20 23:58:14 +00:00
Richard Smith 5b8b3db5c9 Fix a constexpr FIXME: When implicitly instantiating the primary template for an
explicit specialization of a function template, mark the instantiation as
constexpr if the specialization is, rather than requiring them to match.

llvm-svn: 151001
2012-02-20 23:28:05 +00:00
Douglas Gregor fdf598eaf3 Rewrite variable capture within lambda expressions and blocks,
eliminating a bunch of redundant code and properly modeling how the
captures of outside blocks/lambdas affect the types seen by inner
captures.

This new scheme makes two passes over the capturing scope stack. The
first pass goes up the stack (from innermost to outermost), assessing
whether the capture looks feasible and stopping when it either hits
the scope where the variable is declared or when it finds an existing
capture. The second pass then walks down the stack (from outermost to
innermost), capturing the variable at each step and updating the
captured type and the type that an expression referring to that
captured variable would see. It also checks type-specific
restrictions, such as the inability to capture an array within a
block. Note that only the first odr-use of each
variable needs to do the full walk; subsequent uses will find the
capture immediately, so multiple walks need not occur.

The same routine that builds the captures can also compute the type of
the captures without signaling errors and without actually performing
the capture. This functionality is used to determine the type of
declaration references as well as implementing the weird decltype((x))
rule within lambda expressions.

The capture code now explicitly takes sides in the debate over C++
core issue 1249, which concerns the type of captures within nested
lambdas. We opt to use the more permissive, more useful definition
implemented by GCC rather than the one implemented by EDG.

llvm-svn: 150875
2012-02-18 09:37:24 +00:00
Douglas Gregor 812d8f6387 Unify our computation of the type of a captured reference to a
variable; it was previously duplicated, and one of the copies failed
to account for outer non-mutable lambda captures.

llvm-svn: 150872
2012-02-18 05:51:20 +00:00
Douglas Gregor 7ae3c75d97 Only add 'const' to the type of variables captured in a lambda when
we're capturing it by value in a non-mutable lambda.

llvm-svn: 150791
2012-02-17 04:02:59 +00:00
Douglas Gregor a86bc00d3e Lambda closure types are always considered to be like "local" classes,
even if they are not within a function scope. Teach template
instantiation to treat them as such, and make sure that we have a
local instantiation scope when instantiating default arguments and
static data members.

llvm-svn: 150725
2012-02-16 21:36:18 +00:00
Richard Smith 4fa6aec9fe Make sure we still reject static data members in anonymous unions in C++11.
llvm-svn: 150724
2012-02-16 21:23:54 +00:00
Richard Smith 4297375561 C++11 allows unions to have static data members. Remove the corresponding
restriction and add some tests.

llvm-svn: 150721
2012-02-16 20:41:22 +00:00
Richard Smith 17100bad0a constexpr tidyups:
* 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
2012-02-16 02:46:34 +00:00
Douglas Gregor d3b672c385 Implicitly define a lambda's conversion functions (to function
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
2012-02-16 01:06:16 +00:00
Douglas Gregor 33e863cfc8 Lambda closure types have a conversion function to a block pointer
with the same parameter types and return type as the function call
operator. This is the real answer to

  http://stackoverflow.com/questions/4148242/is-it-possible-to-convert-a-c0x-lambda-to-a-clang-block

:)

llvm-svn: 150620
2012-02-15 22:08:38 +00:00
Douglas Gregor 74f7d50f6a When overload resolution picks an implicitly-deleted special member
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
2012-02-15 19:33:52 +00:00
Douglas Gregor 02267a8e48 A little more lambda capture initialization diagnostics cleanup
llvm-svn: 150589
2012-02-15 17:05:32 +00:00
Douglas Gregor 19666fb1aa Introduce a new initialization entity for lambda captures, and
specialize location information and diagnostics for this entity.

llvm-svn: 150588
2012-02-15 16:57:26 +00:00
Douglas Gregor cf11eb76ed Specialize noreturn diagnostics for lambda expressions.
llvm-svn: 150586
2012-02-15 16:20:15 +00:00
Douglas Gregor b9e38f19f7 Specialize the diagnostic complaining about conflicting types of
return statements within a lambda; this diagnostic previously referred
to blocks.

llvm-svn: 150584
2012-02-15 15:57:22 +00:00
Richard Smith b228a86fcf Implement DR1454. This allows all intermediate results in constant expressions
to be core constant expressions (including pointers and references to
temporaries), and makes constexpr calculations Turing-complete. A Turing machine
simulator is included as a testcase.

This opens up the possibilty of removing CCValue entirely, and removing some
copies from the constant evaluator in the process, but that cleanup is not part
of this change.

llvm-svn: 150557
2012-02-15 02:18:13 +00:00
Douglas Gregor adb376ec33 Implement C++ core issue 974, which permits default arguments for
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
2012-02-14 22:28:59 +00:00
Douglas Gregor 621003e7b9 Check the return type of lambda expressions.
llvm-svn: 150503
2012-02-14 21:20:44 +00:00
Douglas Gregor 3e308b1fba Implement support for lambda capture pack expansions, e.g.,
[&values...] { print(values...); }

llvm-svn: 150497
2012-02-14 19:27:52 +00:00
Douglas Gregor 1b66d8c287 Simple test ensuring that we perform direct initialization when copy-capturing in lambdas
llvm-svn: 150442
2012-02-14 00:03:38 +00:00
Douglas Gregor b4328233c1 Link together the call operator produced from transforming a lambda
expression with the original call operator, so that we don't try to
separately instantiate the call operator. Test and tweak a few more
bits for template instantiation of lambda expressions.

llvm-svn: 150440
2012-02-14 00:00:48 +00:00
Richard Smith 6331c408b5 Deal with a horrible C++11 special case. If a non-literal type has a constexpr
constructor, and that constructor is used to initialize an object of static
storage duration such that all members and bases are initialized by constant
expressions, constant initialization is performed. In this case, the object
can still have a non-trivial destructor, and if it does, we must emit a dynamic
initializer which performs no initialization and instead simply registers that
destructor.

llvm-svn: 150419
2012-02-13 22:16:19 +00:00
Douglas Gregor 0c46b2b7ce Introduce support for template instantiation of lambda
expressions. This is mostly a simple refact, splitting the main "start
a lambda expression" function into smaller chunks that are driven
either from the parser (Sema::ActOnLambdaExpr) or during AST
transformation (TreeTransform::TransformLambdaExpr). A few minor
interesting points:

  - Added new entry points for TreeTransform, so that we can
  explicitly establish the link between the lambda closure type in the
  template and the lambda closure type in the instantiation.
  - Added a bit into LambdaExpr specifying whether it had an explicit
  result type or not. We should have had this anyway.

This code is 'lightly' tested.

llvm-svn: 150417
2012-02-13 22:00:16 +00:00
Richard Smith 3607ffee5c Update constexpr implementation to match CWG's chosen approach for core issues
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
2012-02-13 03:54:03 +00:00
Douglas Gregor e096a35518 Implement the standard decltype() semantics described in C++11
[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
2012-02-12 18:57:57 +00:00
Douglas Gregor 81495f341d Within the body of a lambda expression, decltype((x)) for an
id-expression 'x' will compute the type based on the assumption that
'x' will be captured, even if it isn't captured, per C++11
[expr.prim.lambda]p18. There are two related refactors that go into
implementing this:

  1) Split out the check that determines whether we should capture a
  particular variable reference, along with the computation of the
  type of the field, from the actual act of capturing the
  variable. 
  2) Always compute the result of decltype() within Sema, rather than
  AST, because the decltype() computation is now context-sensitive.

llvm-svn: 150347
2012-02-12 18:42:33 +00:00
Douglas Gregor 1a22d2889b Lambdas have a deleted default constructor and a deleted copy
assignment operator, per C++ [expr.prim.lambda]p19. Make it so.

llvm-svn: 150345
2012-02-12 17:34:23 +00:00
Sebastian Redl a935179ab7 Represent C++ direct initializers as ParenListExprs before semantic analysis
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
2012-02-11 23:51:47 +00:00
Eli Friedman c9751069f5 Make sure Sema creates a field for 'this' captures. (Doug, please double-check that this is correct.)
llvm-svn: 150292
2012-02-11 02:51:16 +00:00
Douglas Gregor 28be7c5e20 Add simple semantic test for C++11 [expr.prim.lambda]p16, which covers recursive capture. This is far more interesting for IRgen.
llvm-svn: 150283
2012-02-10 23:38:02 +00:00
Douglas Gregor f0d495100c Implement C++11 [expr.lambda.prim]p13, which prohibits lambdas in
default arguments if in fact those lambdas capture any entity.

llvm-svn: 150282
2012-02-10 23:30:22 +00:00
Douglas Gregor a1bffa26ca Allow implicit capture of 'this' in a lambda even when the capture
default is '=', and reword the warning about explicitly capturing
'this' in such lambdas to indicate that only explicit capture is
banned. 

Introduce Fix-Its for this and other "save the programmer from
themself" rules regarding what can be explicitly captured and what
must be implicitly captured.

llvm-svn: 150256
2012-02-10 17:46:20 +00:00
Douglas Gregor 01db64f0ac Add test from [expr.prim.lambda]p12, which deals with odr-use and
nested captures. We currently don't get odr-use correct in array
bounds, so that bit is commented out while we sort out what we need to
do.

llvm-svn: 150255
2012-02-10 16:48:36 +00:00
Douglas Gregor 04bbab586b Don't introduce a lambda's operator() into the class until after we
have finished parsing the body, so that name lookup will never find
anything within the closure type. Then, add this operator() and the
conversion function (if available) before completing the class.

llvm-svn: 150252
2012-02-10 16:13:20 +00:00
Richard Smith 63168c7533 PR11684, core issue 1417:
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
2012-02-10 11:05:11 +00:00
Douglas Gregor 136b2f24f0 Add a lambda example from the working draft.
llvm-svn: 150239
2012-02-10 09:37:05 +00:00
Douglas Gregor f02455e5ee Add various tests for captures and the reaching scope of the lambda
expression. Implement C++11 [expr.prim.lambda]p12's requirement that
capturing a variable will odr-use it.

llvm-svn: 150237
2012-02-10 09:26:04 +00:00
Douglas Gregor 12695101ec Implement the conversion to a function pointer for lambda expressions,
per C++ [expr.prim.lambda]p6.

llvm-svn: 150236
2012-02-10 08:36:38 +00:00
Richard Smith 0cd4ab194b Update to new resolution for DR1458. When taking the address of an object of
incomplete class type which has an overloaded operator&, it's now just
unspecified whether the overloaded operator or the builtin is used.

llvm-svn: 150234
2012-02-10 07:41:06 +00:00
Douglas Gregor 940a550f0d Don't allow deduction of a lambda result type from an initializer
list; it is not an expression.

llvm-svn: 150194
2012-02-09 18:40:39 +00:00
Douglas Gregor a30a0bc1db Tests for C++ [expr.prim.lambda]p5. We already implement all of these
semantics. 

llvm-svn: 150190
2012-02-09 18:19:44 +00:00
Douglas Gregor 7345626a5b Implement return type deduction for lambdas per C++11
[expr.prim.lambda]p4, including the current suggested resolution of
core isue 975, which allows multiple return statements so long as the
types match. ExtWarn when user code is actually making use of this
extension.

llvm-svn: 150168
2012-02-09 10:18:50 +00:00
Douglas Gregor 656bc62a73 Remove the "unsupported" error for lambda expressions. It's annoying,
and rapidly becoming untrue.

llvm-svn: 150165
2012-02-09 08:26:42 +00:00
Douglas Gregor 291af2b7e6 Add a test for the non-aggregaticity of lambda types per C++11
[expr.prim.lambda].

llvm-svn: 150164
2012-02-09 08:15:36 +00:00
Douglas Gregor 8962549164 Implement C++ [expr.prim.lambda]p2, which bans lambda expressions in
unevaluated operands. Be certain that we're marking everything
referenced within a capture initializer as odr-used.

llvm-svn: 150163
2012-02-09 08:14:43 +00:00
Richard Smith 4d59eebb49 DR1359: A constexpr constructor does not need to initialize an empty struct or
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
2012-02-09 06:40:58 +00:00
Richard Smith 5a294e6a2c CWG issue 1405: mutable members are allowed in literal types, but can't undergo
lvalue-to-rvalue conversions in constant expressions.

llvm-svn: 150145
2012-02-09 03:29:58 +00:00
Douglas Gregor 199cec7673 Implement capture-by-copy for arrays in lambdas.
llvm-svn: 150138
2012-02-09 02:45:47 +00:00
Douglas Gregor 3d23f78852 When we create a non-static data member in the closure object for a
capture, make sure we actually add the field.

llvm-svn: 150135
2012-02-09 02:12:34 +00:00
Douglas Gregor 8c50e7c5e3 Various interrelated cleanups for lambdas:
- Complete the lambda class when we finish the lambda expression
    (previously, it was left in the "being completed" state)
  - Actually return the LambdaExpr object and bind to the resulting
  temporary when needed.
  - Detect when cleanups are needed while capturing a variable into a
  lambda (e.g., due to default arguments in the copy constructor), and
  make sure those cleanups apply for the whole of the lambda
  expression.
    

llvm-svn: 150123
2012-02-09 00:47:04 +00:00
Douglas Gregor 8390afde4e Minor comment fix
llvm-svn: 150090
2012-02-08 21:19:04 +00:00
Douglas Gregor c70fe353ea When computing the type of a local variable reference within a lambda,
only add 'const' for variables captured by copy in potentially
evaluated expressions of non-mutable lambdas. (The "by copy" part was
missing).

llvm-svn: 150088
2012-02-08 20:56:50 +00:00
Douglas Gregor 21f4692c62 When completing a lambda expression, make sure to check and attach the
body of the lambda to the function call operator.

llvm-svn: 150087
2012-02-08 20:17:14 +00:00
Richard Smith 90cacbbf3e Implement DR1458: Taking the address of an object of incomplete class type is
not a constant expression, because we can't tell whether the complete class type
will have an overloaded operator&.

llvm-svn: 150066
2012-02-08 08:11:33 +00:00
Richard Smith 3c7ad4e01b Add more testing for r149776.
llvm-svn: 150061
2012-02-08 06:41:34 +00:00
Richard Smith da7c4ba1af Implement the agreed resolution to DR1457: a signed left shift of a 1 bit into
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
2012-02-08 06:14:53 +00:00
Douglas Gregor e31e606ff3 Introduce basic ASTs for lambda expressions. This covers:
- Capturing variables by-reference and by-copy within a lambda
  - The representation of lambda captures
  - The creation of the non-static data members in the lambda class
  that store the captured variables
  - The initialization of the non-static data members from the
  captured variables
  - Pretty-printing lambda expressions

There are a number of FIXMEs, both explicit and implied, including:
  - Creating a field for a capture of 'this'
  - Improved diagnostics for initialization failures when capturing
  variables by copy
  - Dealing with temporaries created during said initialization
  - Template instantiation
  - AST (de-)serialization
  - Binding and returning the lambda expression; turning it into a
  proper temporary
  - Lots and lots of semantic constraints
  - Parameter pack captures

llvm-svn: 149977
2012-02-07 10:09:13 +00:00
Eli Friedman dd053f6fba Misc improvements to the diagnostic when a variable is odr-used in a context that is not allowed to capture variables.
Fixes PR11883.

llvm-svn: 149937
2012-02-07 00:15:00 +00:00
Richard Smith 2de5a939e2 constexpr: Implement DR1358: An instantiation of a constexpr function which
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
2012-02-05 02:30:54 +00:00
Richard Smith c82fae6070 constexpr: Fix implementation of DR1311: check for volatile qualifiers in
lvalue-to-rvalue conversions on the source type of the conversion, not the
target type (which has them removed for non-class types).

llvm-svn: 149796
2012-02-05 01:23:16 +00:00
Richard Smith f4c51d9d76 In C++11 mode, when an integral constant expression is desired and we have a
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
2012-02-04 09:53:13 +00:00
Richard Smith 3f333f2edf Disallow constexpr main.
llvm-svn: 149770
2012-02-04 06:10:17 +00:00
Eli Friedman 24af850470 Implement implicit capture for lambda expressions.
Still left: explicit captures in lambdas need to cause implicit capture, and I need to take a look at the diagnostics for some cases.

llvm-svn: 149718
2012-02-03 22:47:37 +00:00
Douglas Gregor 1f79ca839c When a pack expansion occurs in the template argument list of an alias
template without a corresponding parameter pack, don't immediately
substitute the alias template. This is under discussion in the C++
committee, and may become ill-formed, but for now we match GCC.

llvm-svn: 149697
2012-02-03 17:16:23 +00:00
Douglas Gregor 8e07261362 Implement support for a pack expansion into a fixed-length
template. Such pack expansions can easily fail at template
instantiation time, if the expanded parameter packs are of the wrong
length. Fixes <rdar://problem/10040867>, PR9021, and the example that
came up today at Going Native.

llvm-svn: 149685
2012-02-03 07:34:46 +00:00
Richard Smith 84f6dcf2b5 constexpr:
* support the gcc __builtin_constant_p() ? ... : ... folding hack in C++11
  * check for unspecified values in pointer comparisons and pointer subtractions

llvm-svn: 149578
2012-02-02 01:16:57 +00:00
Douglas Gregor 6b8ef34f84 Diagnose the restriction on default arguments in C++11 [expr.prim.lambda]p5.
llvm-svn: 149517
2012-02-01 17:18:19 +00:00
Richard Smith 1b470417e4 constexpr: check for overflow in pointer subtraction.
This is a mess. According to the C++11 standard, pointer subtraction only has
undefined behavior if the difference of the array indices does not fit into a
ptrdiff_t.

However, common implementations effectively perform a char* subtraction first,
and then divide the result by the element size, which can cause overflows in
some cases. Those cases are not considered to be undefined behavior by this
change; perhaps they should be.

llvm-svn: 149490
2012-02-01 08:10:20 +00:00