Somewhat surprisingly, signature help is emitted as a side-effect of
computing the expected type of a function argument.
The reason is that both actions require enumerating the possible
function signatures and running partial overload resolution, and doing
this twice would be wasteful and complicated.
Change #1: document this, it's subtle :-)
However, sometimes we need to compute the expected type without having
reached the code completion cursor yet - in particular to allow
completion of designators.
eb4ab3358c did this but introduced a
regression - it emits signature help in the wrong location as a side-effect.
Change #2: only emit signature help if the code completion cursor was reached.
Currently there is PP.isCodeCompletionReached(), but we can't use it
because it's set *after* running code completion.
It'd be nice to set this implicitly when the completion token is lexed,
but ConsumeCodeCompletionToken() makes this complicated.
Change #3: call cutOffParsing() *first* when seeing a completion token.
After this, the fact that the Sema::Produce*SignatureHelp() functions
are even more confusing, as they only sometimes do that.
I don't want to rename them in this patch as it's another large
mechanical change, but we should soon.
Change #4: prepare to rename ProduceSignatureHelp() to GuessArgumentType() etc.
Differential Revision: https://reviews.llvm.org/D98488
lambda from within the lambda-declarator.
Instead of trying to reconstruct whether a parameter pack was declared
inside a lambda (which we can't do correctly in general because we might
not have attached parameters to their declaration contexts yet), track
the set of parameter packs introduced in each live lambda scope, and
require only those parameters to be immediately expanded when they
appear inside that lambda.
In passing, fix incorrect disambiguation of a lambda-expression starting
with an init-capture pack in a braced-init-list. We previously
incorrectly parsed that as a designated initializer.
llvm-svn: 369985
message sends, designators, and attributes.
Instead of having the tentative parsing phase sometimes return an
indicator to say what diagnostic to produce if parsing fails and
sometimes ask the caller to run it again, consistently ask the caller to
try parsing again if tentative parsing would fail or is otherwise unable
to completely parse the lambda-introducer without producing an
irreversible semantic effect.
Mostly NFC, but we should recover marginally better in some error cases
(avoiding duplicate diagnostics).
llvm-svn: 361182
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
We haven't supported compiling ObjC1 for a long time (and never will again), so
there isn't any reason to keep these separate. This patch replaces
LangOpts::ObjC1 and LangOpts::ObjC2 with LangOpts::ObjC.
Differential revision: https://reviews.llvm.org/D53547
llvm-svn: 345637
This implements something like the current direction of DR1581: we use a narrow
syntactic check to determine the set of places where a constant expression
could be evaluated, and only instantiate a constexpr function or variable if
it's referenced in one of those contexts, or is odr-used.
It's not yet clear whether this is the right set of syntactic locations; we
currently consider all contexts within templates that would result in odr-uses
after instantiation, and contexts within list-initialization (narrowing
conversions take another victim...), as requiring instantiation. We could in
principle restrict the former cases more (only const integral / reference
variable initializers, and contexts in which a constant expression is required,
perhaps). However, this is sufficient to allow us to accept libstdc++ code,
which relies on GCC's behavior (which appears to be somewhat similar to this
approach).
llvm-svn: 291318
Teach C++'s tentative parsing to handle specializations of Objective-C
class types (e.g., NSArray<NSString *>) as well as Objective-C
protocol qualifiers (id<NSCopying>) by extending type-annotation
tokens to handle this case. As part of this, remove Objective-C
protocol qualifiers from the declaration specifiers, which never
really made sense: instead, provide Sema entry points to make them
part of the type annotation token. Among other things, this properly
diagnoses bogus types such as "<NSCopying> id" which should have been
written as "id <NSCopying>".
Implements template instantiation support for, e.g., NSArray<T>*
in C++. Note that parameterized classes are not templates in the C++
sense, so that cannot (for example) be used as a template argument for
a template template parameter. Part of rdar://problem/6294649.
llvm-svn: 241545
When messaging a method that was defined in an Objective-C class (or
category or extension thereof) that has type parameters, substitute
the type arguments for those type parameters. Similarly, substitute
into property accesses, instance variables, and other references.
This includes general infrastructure for substituting the type
arguments associated with an ObjCObject(Pointer)Type into a type
referenced within a particular context, handling all of the
substitutions required to deal with (e.g.) inheritance involving
parameterized classes. In cases where no type arguments are available
(e.g., because we're messaging via some unspecialized type, id, etc.),
we substitute in the type bounds for the type parameters instead.
Example:
@interface NSSet<T : id<NSCopying>> : NSObject <NSCopying>
- (T)firstObject;
@end
void f(NSSet<NSString *> *stringSet, NSSet *anySet) {
[stringSet firstObject]; // produces NSString*
[anySet firstObject]; // produces id<NSCopying> (the bound)
}
When substituting for the type parameters given an unspecialized
context (i.e., no specific type arguments were given), substituting
the type bounds unconditionally produces type signatures that are too
strong compared to the pre-generics signatures. Instead, use the
following rule:
- In covariant positions, such as method return types, replace type
parameters with “id” or “Class” (the latter only when the type
parameter bound is “Class” or qualified class, e.g,
“Class<NSCopying>”)
- In other positions (e.g., parameter types), replace type
parameters with their type bounds.
- When a specialized Objective-C object or object pointer type
contains a type parameter in its type arguments (e.g.,
NSArray<T>*, but not NSArray<NSString *> *), replace the entire
object/object pointer type with its unspecialized version (e.g.,
NSArray *).
llvm-svn: 241543
Now that SmallString is a first-class citizen, most SmallString::str()
calls are not required. This patch removes a whole bunch of them, yet
there are lots more.
There are two use cases where str() is really needed:
1) To use one of StringRef member functions which is not available in
SmallString.
2) To convert to std::string, as StringRef implicitly converts while
SmallString do not. We may wish to change this, but it may introduce
ambiguity.
llvm-svn: 232622
Introduce proper facilities to render token spellings using the diagnostic
formatter.
Replaces most of the hard-coded diagnostic messages related to expected tokens,
which all shared the same semantics but had to be multiply defined due to
variations in token order or quote marks.
The associated parser changes are largely mechanical but they expose
commonality in whole chunks of the parser that can now be factored away.
This commit uses C++11 typed enums along with a speculative legacy fallback
until the transition is complete.
Requires corresponding changes in LLVM r197895.
llvm-svn: 197972
module. Use the marker to diagnose cases where we try to transition between
submodules when not at the top level (most likely because a closing brace was
missing at the end of a header file, but is also possible if submodule headers
attempt to do something fundamentally non-modular, like our .def files).
llvm-svn: 195543
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
* 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
designators in the parser. In the worst case, this disambiguation
requires tentative parsing just past the closing ']', but for most
cases we'll be able to tell by looking ahead just one token (without
going into the heavyweight tentative parsing machinery).
llvm-svn: 150790
Necessary to parse Microsoft ATL code.
Example:
int array[] = {
0,
__if_exists(CLASS::Type) {2, }
3
};
will declare an array of 2 or 3 elements depending on if CLASS::Type exists or not.
llvm-svn: 146447
part of parser recovery. For example, given:
a method1:arg];
we detect after parsing the expression "a" that we have the start of a
message send expression. We pretend we've seen a '[' prior to the a,
then parse the remainder as a message send. We'll then give a
diagnostic+fix-it such as:
fixit-objc-message.m:17:3: error: missing '[' at start of message
send expression
a method1:arg];
^
[
The algorithm here is very simple, and always assumes that the open
bracket goes at the beginning of the message send. It also only works
for non-super instance message sends at this time.
llvm-svn: 113968
One who seeks the Tao unlearns something new every day.
Less and less remains until you arrive at non-action.
When you arrive at non-action,
nothing will be left undone.
llvm-svn: 112244
Sam McCall