Specifically, the following features are not included in this commit:
- any sort of capturing within generic lambdas
- nested lambdas
- conversion operator for captureless lambdas
- ensuring all visitors are generic lambda aware
As an example of what compiles:
template <class F1, class F2>
struct overload : F1, F2 {
using F1::operator();
using F2::operator();
overload(F1 f1, F2 f2) : F1(f1), F2(f2) { }
};
auto Recursive = [](auto Self, auto h, auto ... rest) {
return 1 + Self(Self, rest...);
};
auto Base = [](auto Self, auto h) {
return 1;
};
overload<decltype(Base), decltype(Recursive)> O(Base, Recursive);
int num_params = O(O, 5, 3, "abc", 3.14, 'a');
Please see attached tests for more examples.
Some implementation notes:
- Add a new Declarator context => LambdaExprParameterContext to
clang::Declarator to allow the use of 'auto' in declaring generic
lambda parameters
- Augment AutoType's constructor (similar to how variadic
template-type-parameters ala TemplateTypeParmDecl are implemented) to
accept an IsParameterPack to encode a generic lambda parameter pack.
- Add various helpers to CXXRecordDecl to facilitate identifying
and querying a closure class
- LambdaScopeInfo (which maintains the current lambda's Sema state)
was augmented to house the current depth of the template being
parsed (id est the Parser calls Sema::RecordParsingTemplateParameterDepth)
so that Sema::ActOnLambdaAutoParameter may use it to create the
appropriate list of corresponding TemplateTypeParmDecl for each
auto parameter identified within the generic lambda (also stored
within the current LambdaScopeInfo). Additionally,
a TemplateParameterList data-member was added to hold the invented
TemplateParameterList AST node which will be much more useful
once we teach TreeTransform how to transform generic lambdas.
- SemaLambda.h was added to hold some common lambda utility
functions (this file is likely to grow ...)
- Teach Sema::ActOnStartOfFunctionDef to check whether it
is being called to instantiate a generic lambda's call
operator, and if so, push an appropriately prepared
LambdaScopeInfo object on the stack.
- Teach Sema::ActOnStartOfLambdaDefinition to set the
return type of a lambda without a trailing return type
to 'auto' in C++1y mode, and teach the return type
deduction machinery in SemaStmt.cpp to process either
C++11 and C++14 lambda's correctly depending on the flag.
- various tests were added - but much more will be needed.
A greatful thanks to all reviewers including Eli Friedman,
James Dennett and the ever illuminating Richard Smith. And
yet I am certain that I have allowed unidentified bugs to creep in;
bugs, that I will do my best to slay, once identified!
Thanks!
llvm-svn: 188977
*that* easy...
Try a bit harder to disambiguate. This is mostly straightforward, but for
=-style initializers, we actually need to know where an expression ends:
[foo = bar baz]
is a message send, whereas
[foo = bar + baz]
is a lambda-introducer. Handle this by parsing the expression eagerly, and
replacing it with an annotation token. By chance, we use the *exact same*
parsing rules in both cases (except that we need to assume we're inside a
message send for the parse, to turn off various forms of inapplicable
error recovery).
llvm-svn: 182432
a FieldDecl from it, and propagate both into the closure type and the
LambdaExpr.
You can't do much useful with them yet -- you can't use them within the body
of the lambda, because we don't have a representation for "the this of the
lambda, not the this of the enclosing context". We also don't have support or a
representation for a nested capture of an init-capture yet, which was intended
to work despite not being allowed by the current standard wording.
llvm-svn: 181985
are now two distinct canonical 'AutoType's: one is the undeduced 'auto'
placeholder type, and the other is a deduced-but-dependent type. All
deduced-to-a-non-dependent-type cases are still non-canonical.
llvm-svn: 180789
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
uncovered.
This required manually correcting all of the incorrect main-module
headers I could find, and running the new llvm/utils/sort_includes.py
script over the files.
I also manually added quite a few missing headers that were uncovered by
shuffling the order or moving headers up to be main-module-headers.
llvm-svn: 169237
typeid (and a couple other non-standard places where we can transform an
unevaluated expression into an evaluated expression) is special
because it introduces an an expression evaluation context,
which conflicts with the mechanism to compute the current
lambda mangling context. PR12123.
I would appreciate if someone would double-check that we get the mangling
correct with this patch.
llvm-svn: 164658
nested names as id-expressions, using the annot_primary_expr annotation, where
possible. This removes some redundant lookups, and also allows us to
typo-correct within tentative parsing, and to carry on disambiguating past an
identifier which we can determine will fail lookup as both a type and as a
non-type, allowing us to disambiguate more declarations (and thus offer
improved error recovery for such cases).
This also introduces to the parser the notion of a tentatively-declared name,
which is an identifier which we *might* have seen a declaration for in a
tentative parse (but only if we end up disambiguating the tokens as a
declaration). This is necessary to correctly disambiguate cases where a
variable is used within its own initializer.
llvm-svn: 162159
lambda-introducer in Objective-C++11, fall back to treating the tokens
as an Objective-C message send to provide those (more likely)
completions. Fixes <rdar://problem/11980263>.
llvm-svn: 161015
accurate by asking the parser whether there was an ambiguity rather than trying
to reverse-engineer it from the DeclSpec. Make the with-parameters case have
better diagnostics by using semantic information to drive the warning,
improving the diagnostics and adding a fixit.
Patch by Nikola Smiljanic. Some minor changes by me to suppress diagnostics for
declarations of the form 'T (*x)(...)', which seem to have a very high false
positive rate, and to reduce indentation in 'warnAboutAmbiguousFunction'.
llvm-svn: 160998
attributes in more places where we didn't and catching a lot more issues.
This implements nearly every aspect of C++11 attribute parsing, except for:
- Attributes are permitted on explicit instantiations inside the declarator
(but not preceding the decl-spec)
- Attributes are permitted on friend declarations of functions.
- Multiple instances of the same attribute in an attribute-list (e.g.
[[noreturn, noreturn]], not [[noreturn]] [[noreturn]] which is conforming)
are allowed.
The first two are marked as expected-FIXME in the test file and the latter
is probably a defect and is currently untested.
Thanks to Richard Smith for providing the lion's share of the testcases.
llvm-svn: 159072
also deal with '>>>' (in CUDA), '>=', and '>>='. Fix the FixItHints logic to
deal with cases where the token is followed by an adjacent '=', '==', '>=',
'>>=', or '>>>' token, where a naive fix-it would result in a differing token
stream on a re-lex.
llvm-svn: 158652
refactorings in that revision, and some of the subsequent bugfixes, which
seem to be relevant even without delayed exception specification parsing.
llvm-svn: 156031
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
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
Instead, make it the allocation function's responsibility to add them
to a list and clear it when a top-level decl is finished.
This plugs leakage of TemplateAnnotationIds. DelayedCleanupPool is
ugly and unused, remove it.
llvm-svn: 154743
* 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 type specifier and can be combined with unsigned. This allows libstdc++4.7 to
be used with clang in c++98 mode.
Several other changes are still required for libstdc++4.7 to work with clang in
c++11 mode.
llvm-svn: 153999
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
for a few kinds of error. Specifically:
Since we're after translation phase 6, the "" token might be formed by multiple
source-level string literals. Checking the token width is not a correct way of
detecting empty string literals, due to escaped newlines. Diagnose and recover
from a missing space between "" and suffix, and from string literals other than
"", which are followed by a suffix.
llvm-svn: 152348
