Specifically, the following features are not included in this commit:
- any sort of capturing within generic lambdas
- generic lambdas within template functions and nested
within other generic lambdas
- conversion operator for captureless lambdas
- ensuring all visitors are generic lambda aware
(Although I have gotten some useful feedback on my patches of the above and will be incorporating that as I submit those patches for commit)
As an example of what compiles through this commit:
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.
This patch has been reviewed by Doug and Richard. Minor changes (non-functionality affecting) have been made since both of them formally looked at it, but the changes involve removal of supernumerary return type deduction changes (since they are now redundant, with richard having committed a recent patch to address return type deduction for C++11 lambdas using C++14 semantics).
Some implementation notes:
- Add a new Declarator context => LambdaExprParameterContext to
clang::Declarator to allow the use of 'auto' in declaring generic
lambda parameters
- 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 SemaType.cpp::ConvertDeclSpecToType may use it to immediately
generate a template-parameter-type when 'auto' is parsed in a generic
lambda parameter context. (i.e we do NOT use AutoType deduced to
a template parameter type - Richard seemed ok with this approach).
We encode that this template type was generated from an auto by simply
adding $auto to the name which can be used for better diagnostics if needed.
- 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.
- various tests were added - but much more will be needed.
There is obviously more work to be done, and both Richard (weakly) and Doug (strongly)
have requested that LambdaExpr be removed form the CXXRecordDecl LambdaDefinitionaData
in a future patch which is forthcoming.
A greatful thanks to all reviewers including Eli Friedman, James Dennett,
and especially the two gracious wizards (Richard Smith and Doug Gregor)
who spent hours providing feedback (in person in Chicago and on the mailing lists).
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: 191453
Unlike with namespaces, searching inside of classes requires also
checking the access to correction candidates (i.e. don't suggest a
correction to a private class member for a correction occurring outside
that class and its methods or friends).
Included is a small (one line) fix for a bug, that was uncovered while
cleaning up the unit tests, where the decls from a TypoCorrection candidate
were preserved in new TypoCorrection candidates that are derived (copied)
from the old TypoCorrection--notably when creating a new candidate by
changing the NestedNameSpecifier associated with the base idenitifer.
llvm-svn: 191449
fields in the class. This allows a better checking of member intiailizers and
in class initializers in regards to initialization ordering.
For instance, this code will now produce warnings:
class A {
int x;
int y;
A() : x(y) {} // y is initialized after x, warn here
A(int): y(x) {} // default initialization of leaves x uninitialized, warn here
};
Several test cases were updated with -Wno-uninitialized to silence this warning.
llvm-svn: 191068
variable from being the function to being the enclosing namespace scope (in
C++) or the TU (in C). This allows us to fix a selection of related issues
where we would build incorrect redeclaration chains for such declarations, and
fail to notice type mismatches.
Such declarations are put into a new IdentifierNamespace, IDNS_LocalExtern,
which is only found when searching scopes, and not found when searching
DeclContexts. Such a declaration is only made visible in its DeclContext if
there are no non-LocalExtern declarations.
llvm-svn: 191064
non-member function, the number of arguments in the two candidate calls
will be different (the non-member call will have one extra argument).
We used to get confused by this, and fail to compare the last argument
when testing whether the member is better, resulting in us always
thinking it is, even if the non-member is more specialized in the last
argument.
llvm-svn: 190470
Exception specs are not part of the canonical type, but we shouldn't
drop them just because we merged a noreturn attribute.
Fixes PR17110.
llvm-svn: 190206
Consider something like the following:
struct X {
virtual void foo(float x);
};
struct Y : X {
void foo(double x) override;
};
The error is almost certainly that Y::foo() has the wrong signature,
rather than incorrect usage of the override keyword. This patch
adds an appropriate diagnostic for that case.
Fixes <rdar://problem/14785106>.
llvm-svn: 190109
been an oversight, as it definitely works. Every test which changed had
the const written on the LHS of the auto already.
Notably, this also makes things like cpp11-migrate's formation of 'const
auto &' variables much more familiar.
Yes, many people feel that 'const' and other qualifiers belong on the
RHS of the type. I'm not going to argue about that because Clang already
*overwhelming* places the qualifiers on the LHS when it can and on the
RHS when it must. We shouldn't diverge for auto. We should add a tool to
clang-tidy that fixes this in either direction, and then wire up
clang-tidy to tools like cpp11-migrate to fix their placement after
transforms.
llvm-svn: 189769
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
When a local extern declaration redeclares some other entity, the type of that
entity is merged with the prior type if the prior declaration is visible (in C)
or is declared in the same scope (in C++).
- Make LookupRedeclarationWithLinkage actually work in C++, use it in the right
set of cases, and make it track whether it found a shadowed declaration.
- Track whether we found a declaration in the same scope (for C++) including
across serialization and template instantiation.
llvm-svn: 188307
of local classes. We were previously handling this by performing qualified
lookup within a function declaration(!!); replace it with the proper scope
lookup.
llvm-svn: 188050
function: it can't be 'void' and it can't be an initializer list. We give a
hard error for these rather than treating them as undefined behavior (we can
and probably should do the same for non-POD types in C++11, but as of this
change we don't).
Slightly rework the checking of variadic arguments in a function with a format
attribute to ensure that certain kinds of format string problem (non-literal
string, too many/too few arguments, ...) don't suppress this error.
llvm-svn: 187735
We would disallow the case where the overloaded member expression is
coming from an address-of operator but we wouldn't issue any diagnostics
when the overloaded member expression comes by way of a function to
pointer decay cast.
Clang's implementation of DR61 is now seemingly complete.
llvm-svn: 187559
Switch some warnings over to errors which should never have been warnings
in the first place. (Also, a minor fix to the preprocessor rules for
integer literals while I'm here.)
llvm-svn: 186903
This patch essentially removes all the FIXMEs following calls to DeduceTemplateArguments() that want to keep track of deduction failure info.
llvm-svn: 186730
r186331).
Original commit log:
If we friend a declaration twice, that should not make it visible to
name lookup in the surrounding context. Slightly rework how we handle
friend declarations to inherit the visibility of the prior
declaration, rather than setting a friend declaration to be visible
whenever there was a prior declaration.
llvm-svn: 186546
This breaks the build of basic patterns with repeated friend
declarations. See the added test case in SemaCXX/friend.cpp or the test
case reported to the original commit log.
Original commit log:
If we friend a declaration twice, that should not make it visible to
name lookup in the surrounding context. Slightly rework how we handle
friend declarations to inherit the visibility of the prior
declaration, rather than setting a friend declaration to be visible
whenever there was a prior declaration.
llvm-svn: 186331
does not substitute a sizeof-pack expression.
The solution is proposed by Richard Smith.
Differential Revision: http://llvm-reviews.chandlerc.com/D869
llvm-svn: 186306
Test coverage for non-dependent pack expansions doesn't demonstrate a
failure prior to this patch (a follow-up commit improving debug info
will cover this commit specifically) but covers a related hole in our
test coverage.
Reviewed by Richard Smith & Eli Friedman.
llvm-svn: 186261
Original commit log:
If we friend a declaration twice, that should not make it visible to
name lookup in the surrounding context. Slightly rework how we handle
friend declarations to inherit the visibility of the prior
declaration, rather than setting a friend declaration to be visible
whenever there was a prior declaration.
llvm-svn: 186199
fix is.
Original commit log:
If we friend a declaration twice, that should not make it visible to
name lookup in the surrounding context. Slightly rework how we handle
friend declarations to inherit the visibility of the prior
declaration, rather than setting a friend declaration to be visible
whenever there was a prior declaration.
llvm-svn: 186185
lookup in the surrounding context. Slightly rework how we handle friend
declarations to inherit the visibility of the prior declaration, rather
than setting a friend declaration to be visible whenever there was a prior
declaration.
llvm-svn: 186040
Sema::MergeFunctionDecl attempts merging two decls even if the old decl
is invalid. This can lead to interesting circumstances where we
successfully merge the decls but the result makes no sense.
Take the following for example:
template <typename T>
int main(void);
int main(void);
Sema will not consider these to be overloads of the same name because
main can't be overloaded, which means that this must be a redeclaration.
In this case the templated decl is compatible with the non-templated
decl allowing the Sema::CheckFunctionDeclaration machinery to move on
and do bizarre things like setting the previous decl of a non-templated
decl to a templated decl!
The way I see it, we should just bail from MergeFunctionDecl if the old
decl is invalid.
This fixes PR16531.
llvm-svn: 185779
This boils down to us sending invalid function decls to
CheckFunctionDeclaration becauswe we did not consider that CheckMain
could cause the decl to be invalid. Instead, interogate the new decl's
main-validity and *then* send it over to get CheckFunctionDeclaration'd
if it was still valid after calling CheckMain.
llvm-svn: 185745
The test was passing because clang would still print the ast before exiting
with an error. Since that didn't seem to be the intent of the test, I change
the test instead of adding 'not' to the command line.
llvm-svn: 185634
The removal is tried by retrying the failed lookup of a correction
candidate with either the MemberContext or SS (CXXScopeSpecifier) or
both set to NULL if they weren't already. If the candidate identifier
is then looked up successfully, make a note in the candidate that the
SourceRange should include any existing nested name specifier even if
the candidate isn't adding a different one (i.e. the candidate has a
NULL NestedNameSpecifier).
Also tweak the diagnostic messages to differentiate between a suggestion
that just replaces the identifer but leaves the existing nested name
specifier intact and one that replaces the entire qualified identifier,
in cases where the suggested replacement is unqualified.
llvm-svn: 185487
Make sure we properly treat names defined inside a block as local
names. There are basically three fixes here. One, correctly
treat blocks as a context where we need to use local-name mangling using
the new isLocalContainerContext helper. Two, make
CXXNameMangler::manglePrefix handle local names in a consistent way.
Three, extend CXXNameMangler::mangleLocalName so it can mangle a block
correctly.
llvm-svn: 185450
This commit rearranges the logic in CXXNameMangler::mangleLocalName and
GetLocalClassDecl so that it doesn't accidentally skip over lambdas. It
also reduces code duplication a bit.
llvm-svn: 185402
Blocks, like lambdas, can be written in contexts which are required to be
treated as the same under ODR. Unlike lambdas, it isn't possible to actually
take the address of a block, so the mangling of the block itself doesn't
matter. However, objects like static variables inside a block do need to
be mangled in a consistent way.
There are basically three components here. One, block literals need a
consistent numbering. Two, objects/types inside a block literal need
to be mangled using it. Three, objects/types inside a block literal need
to have their linkage computed correctly.
llvm-svn: 185372
standard's rule that an extern "C" declaration conflicts with any entity in the
global scope with the same name. Now we only care if the global scope entity is
a variable declaration (and so might have the same mangled name as the extern
"C" declaration). This has been reported as a standard defect.
Original commit message:
PR7927, PR16247: Reimplement handling of matching extern "C" declarations
across scopes.
When we declare an extern "C" name that is not a redeclaration of an entity in
the same scope, check whether it redeclares some extern "C" entity from another
scope, and if not, check whether it conflicts with a (non-extern-"C") entity in
the translation unit.
When we declare a name in the translation unit that is not a redeclaration,
check whether it conflicts with any extern "C" entities (possibly from other
scopes).
llvm-svn: 185281
across scopes.
When we declare an extern "C" name that is not a redeclaration of an entity in
the same scope, check whether it redeclares some extern "C" entity from another
scope, and if not, check whether it conflicts with a (non-extern-"C") entity in
the translation unit.
When we declare a name in the translation unit that is not a redeclaration,
check whether it conflicts with any extern "C" entities (possibly from other
scopes).
llvm-svn: 185229
A default template-argument shall not be specified in a friend template
declaration.
Interestingly, we properly handled default template arguments on friend
class members but not on just friend classes.
llvm-svn: 184882
This changes the mangling of local static variables/etc. inside blocks
to do something simple and sane. This avoids depending on the way we mangle
blocks, which isn't really appropriate here.
John, please take a look at this to make sure the mangling I chose is sane.
Fixes <rdar://problem/14074423>.
llvm-svn: 184780
The problem with r183462 was that we assumed that a diagnostic id of
zero would be silent.
This small correction to CheckDerivedToBaseConversion changes it's
behavior to omit the diagnostic when given a diagnostic id of zero.
This fix passes the test case added in r184402.
llvm-svn: 184631
the result of a cast-to-reference-type lifetime-extends the object to which the
reference inside the cast binds.
This requires us to look for subobject adjustments on both the inside and the
outside of the MaterializeTemporaryExpr when looking for a temporary to
lifetime-extend (which we also need for core issue 616, and possibly 1213).
llvm-svn: 184024
- 'register' storage class
- dynamic exception specifications
Only the former check is enabled by default for now (the latter might be quite noisy).
llvm-svn: 183881
Introduce CXXStdInitializerListExpr node, representing the implicit
construction of a std::initializer_list<T> object from its underlying array.
The AST representation of such an expression goes from an InitListExpr with a
flag set, to a CXXStdInitializerListExpr containing a MaterializeTemporaryExpr
containing an InitListExpr (possibly wrapped in a CXXBindTemporaryExpr).
This more detailed representation has several advantages, the most important of
which is that the new MaterializeTemporaryExpr allows us to directly model
lifetime extension of the underlying temporary array. Using that, this patch
*drastically* simplifies the IR generation of this construct, provides IR
generation support for nested global initializer_list objects, fixes several
bugs where the destructors for the underlying array would accidentally not get
invoked, and provides constant expression evaluation support for
std::initializer_list objects.
llvm-svn: 183872
CXXCtorInitializers to the point where we perform the questionable lifetime
extension. This exposed a selection of false negatives in the warning.
llvm-svn: 183869
places which weren't setting it up properly. This allows us to get the right
cv-qualifiers for 'this' when it appears outside a method body in a class
template.
llvm-svn: 183483
Disallowing deriving from classes that have private virtual base classes
except in instances where the deriving class would be able to cast
itself to the private virtual base via a different derivation.
llvm-svn: 183462
Still missing cases for templates, but this is a step in the right
direction. Also omits suggestions that would be ambiguous (eg: void
func(int = 0); + void func(float = 0); func;)
llvm-svn: 183173
materialized temporary with the corresponding MaterializeTemporaryExpr. This is
groundwork for providing C++11's guaranteed static initialization for global
references bound to lifetime-extended temporaries (if the initialization is a
constant expression).
In passing, fix a couple of bugs where some evaluation failures didn't trigger
diagnostics, and a rejects-valid where potential constant expression testing
would assume that it knew the dynamic type of *this and would reject programs
which relied on it being some derived type.
llvm-svn: 183093
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
- References to ObjC bit-field ivars are bit-field lvalues;
fixes rdar://13794269, which got me started down this.
- Introduce Expr::refersToBitField, switch a couple users to
it where semantically important, and comment the difference
between this and the existing API.
- Discourage Expr::getBitField by making it a bit longer and
less general-sounding.
- Lock down on const_casts of bit-field gl-values until we
hear back from the committee as to whether they're allowed.
llvm-svn: 181252
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
Add a CXXDefaultInitExpr, analogous to CXXDefaultArgExpr, and use it both in
CXXCtorInitializers and in InitListExprs to represent a default initializer.
There's an additional complication here: because the default initializer can
refer to the initialized object via its 'this' pointer, we need to make sure
that 'this' points to the right thing within the evaluation.
llvm-svn: 179958
For this source:
const int &ref = someStruct.bitfield;
We used to generate this AST:
DeclStmt [...]
`-VarDecl [...] ref 'const int &'
`-MaterializeTemporaryExpr [...] 'const int' lvalue
`-ImplicitCastExpr [...] 'const int' lvalue <NoOp>
`-MemberExpr [...] 'int' lvalue bitfield .bitfield [...]
`-DeclRefExpr [...] 'struct X' lvalue ParmVar [...] 'someStruct' 'struct X'
Notice the lvalue inside the MaterializeTemporaryExpr, which is very
confusing (and caused an assertion to fire in the analyzer - PR15694).
We now generate this:
DeclStmt [...]
`-VarDecl [...] ref 'const int &'
`-MaterializeTemporaryExpr [...] 'const int' lvalue
`-ImplicitCastExpr [...] 'int' <LValueToRValue>
`-MemberExpr [...] 'int' lvalue bitfield .bitfield [...]
`-DeclRefExpr [...] 'struct X' lvalue ParmVar [...] 'someStruct' 'struct X'
Which makes a lot more sense. This allows us to remove code in both
CodeGen and AST that hacked around this special case.
The commit also makes Clang accept this (legal) C++11 code:
int &&ref = std::move(someStruct).bitfield
PR15694 / <rdar://problem/13600396>
llvm-svn: 179250
constructor. This isn't quite perfect (as usual, we don't handle default
arguments correctly yet, and we don't deal with copy/move constructors for
arguments correctly either, but this will be fixed when we implement core issue
1351.
This completes our support for inheriting constructors.
llvm-svn: 179154
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
This fixes a regression I introduced in r178136, where we would not
consider the using directives from the semantic declaration contexts
that aren't represented by the lexical scopes (Scope) when performing
unqualified name lookup. This lead to horribly funny diagnostics like
"no identifier named 'foo'; did you mean 'foo'?".
llvm-svn: 179067
overriding a non-deleted virtual function. The existing check for this doesn't
catch this case, because it fires before we mark the method as deleted.
llvm-svn: 178563
visible. There's a lot of potential badness in how we're modelling
these things, but getting this much correct is reasonably easy.
rdar://13535367
llvm-svn: 178488
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
accessible in its declaring class; otherwise we might
fail to apply [class.protected] when considering
accessibility in derived classes.
Noticed by inspection; <rdar://13270329>.
I had an existing test wrong. Here's why it's wrong:
Follow the rules (and notation) of [class.access]p5.
The naming class (N) is B and the context (R) is D::getX.
- 'x' as a member of B is protected, but R does not occur
in a member or friend of a class derived from B.
- There does exist a base class of B, A, which is accessible
from R, and 'x' is accessible at R when named in A because
'x' as a member of A is protected and R occurs in a member
of a class, D, that is derived from A; however, by
[class.protected], the class of the object expression must
be equal to or derived from that class, and A does not
derive from D.
llvm-svn: 175858
MSVC accepts this:
class A {
A::A();
};
Clang accepts regular member functions with extra qualification as an MS
extension, but not constructors. This changes the parser to defer rejecting
qualified constructors so that the same Sema logic can apply to constructors as
regular member functions. This also improves the error message when MS
extensions are disabled (in my opinion). Before it was:
/Users/jason/Desktop/test.cpp:2:8: error: expected member name or ';' after declaration specifiers
A::A();
~~~~ ^
1 error generated.
After:
/Users/jason/Desktop/test.cpp:2:6: error: extra qualification on member 'A'
A::A();
~~~^
1 error generated.
Patch by Jason Haslam.
llvm-svn: 174980
have a direct mismatch between some component of the template and some
component of the argument. The diagnostic now says what the mismatch was, but
doesn't yet say which part of the template doesn't match.
llvm-svn: 174039
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
Faisal Vali