- 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
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
Language-design credit goes to a lot of people, but I particularly want
to single out Blaine Garst and Patrick Beard for their contributions.
Compiler implementation credit goes to Argyrios, Doug, Fariborz, and myself,
in no particular order.
llvm-svn: 133103
behind implicit moves. We now correctly identify move constructors and
assignment operators and update bits on the record correctly. Generation
of implicit moves (declarations or definitions) is not yet supported.
llvm-svn: 132080
hasTrivialDefaultConstructor() really really means it now.
Also implement a fun standards bug regarding aggregates. Doug, if you'd
like, I can un-implement that bug if you think it is truly a defect.
The bug is that non-special-member constructors are never considered
user-provided, so the following is an aggregate:
struct foo {
foo(int);
};
It's kind of bad, but the solution isn't obvious - should
struct foo {
foo (int) = delete;
};
be an aggregate or not?
Lastly, add a missing initialization to FunctionDecl.
llvm-svn: 131101
type trait. The previous implementation suffered from several problems:
1) It implemented all of the logic in RecordType by walking over every
base and field in a CXXRecordDecl and validating the constraints of
the standard. This made for very straightforward code, but is
extremely inefficient. It also is conceptually wrong, the logic tied
to the C++ definition of standard-layout classes should be in
CXXRecordDecl, not RecordType.
2) To address the performance problems with #1, a cache bit was added to
CXXRecordDecl, and at the completion of every C++ class, the
RecordType was queried to determine if it was a standard layout
class, and that state was cached. Two things went very very wrong
with this. First, the caching version of the query *was never
called*. Even within the recursive steps of the walk over all fields
and bases the caching variant was not called, making each query
a full *recursive* walk. Second, despite the cache not being used, it
was computed for every class declared, even when the trait was never
used in the program. This probably significantly regressed compile
time performance for edge-case files.
3) An ASTContext was required merely to query the type trait because
querying it performed the actual computations.
4) The caching bit wasn't managed correctly (uninitialized).
The new implementation follows the system for all the other traits on
C++ classes by encoding all the state needed in the definition data and
building up the trait incrementally as each base and member are added to
the definition of the class.
The idiosyncracies of the specification of standard-layout classes
requires more state than I would like; currently 5 bits. I could
eliminate one of the bits easily at the expense of both clarity and
resilience of the code. I might be able to eliminate one of the other
bits by computing its state in terms of other state bits in the
definition. I've already done that in one place where there was a fairly
simple way to achieve it.
It's possible some of the bits could be moved out of the definition data
and into some other structure which isn't serialized if the serialized
bloat is a problem. That would preclude serialization of a partial class
declaration, but that's likely already precluded.
Comments on any of these issues welcome.
llvm-svn: 130601
Patch authored by John Wiegley.
These type traits are used for parsing code that employs certain features of
the Embarcadero C++ compiler. Several of these constructs are also desired by
libc++, according to its project pages (such as __is_standard_layout).
llvm-svn: 130342
operators in C++ record declarations.
This patch starts off by updating a bunch of the standard citations to
refer to the draft 0x standard so that the semantics intended for move
varianst is clear. Where necessary these are duplicated so they'll be
available in doxygen.
It adds bit fields to keep track of the state for the move constructs,
and updates all the code necessary to track this state (I think) as
members are declared for a class. It also wires the state into the
various trait-like accessors in the AST's API, and tests that the type
trait expressions now behave correctly in the presence of move
constructors and move assignment operators.
This isn't complete yet due to these glaring FIXMEs:
1) No synthesis of implicit move constructors or assignment operators.
2) I don't think we correctly enforce the new logic for both copy and
move trivial checks: that the *selected* copy/move
constructor/operator is trivial. Currently this requires *all* of them
to be trivial.
3) Some of the trait logic needs to be folded into the fine-grained
trivial bits to more closely match the wording of the standard. For
example, many of the places we currently set a bit to track POD-ness
could be removed by querying other more fine grained traits on
demand.
llvm-svn: 130076
This introduces a few APIs on the AST to bundle up the standard-based
logic so that programmatic clients have access to exactly the same
behavior.
There is only one serious FIXME here: checking for non-trivial move
constructors and move assignment operators. Those bits need to be added
to the declaration and accessors provided.
This implementation should be enough for the uses of __is_trivial in
libstdc++ 4.6's C++98 library implementation.
Ideas for more thorough test cases or any edge cases missing would be
appreciated. =D
llvm-svn: 130057
out-of-line destructors can result in the addition of redundant
destructors to a class. It's not harmful to the AST. Fixes
<rdar://problem/9158632>.
llvm-svn: 129860
This successfully performs constructor lookup and verifies that a
delegating initializer is the only initializer present.
This does not perform loop detection in the initialization, but it also
doesn't codegen delegating constructors at all, so this won't cause
runtime infinite loops yet.
llvm-svn: 126552
UnresolvedUsingValueDecl to use NestedNameSpecifierLoc rather than the
extremely-lossy NestedNameSpecifier/SourceRange pair it used to use,
improving source-location information.
Various infrastructure updates to support NestedNameSpecifierLoc:
- AST/PCH (de-)serialization
- Recursive AST visitor
- libclang traversal (including the first tests of this
functionality)
llvm-svn: 126459
lead to a serious slowdown (4%) on parsing of Cocoa.h. This memory
optimization should be revisited later, when we have time to look at
the generated code.
llvm-svn: 126033
when returning an NRVO candidate expression. For example, this
properly picks the move constructor when dealing with code such as
MoveOnlyType f() { MoveOnlyType mot; return mot; }
The previously-XFAIL'd rvalue-references test case now works, and has
been moved into the appropriate paragraph-specific test case.
llvm-svn: 123992
Richard Smith