Summary:
This feature was discussed but not yet proposed. It allows a structured binding to appear as a //condition//
if (auto [ok, val] = f(...))
So the user can save an extra //condition// if the statement can test the value to-be-decomposed instead. Formally, it makes the value of the underlying object of the structured binding declaration also the value of a //condition// that is an initialized declaration.
Considering its logicality which is entirely evident from its trivial implementation, I think it might be acceptable to land it as an extension for now before I write the paper.
Reviewers: rsmith, faisalv, aaron.ballman
Reviewed By: rsmith
Subscribers: aaron.ballman, cfe-commits
Differential Revision: https://reviews.llvm.org/D39284
llvm-svn: 320011
This is a recommit of r312781; in some build configurations
variable names are omitted, so changed the new regression
test accordingly.
llvm-svn: 312794
This adds _Float16 as a source language type, which is a 16-bit floating point
type defined in C11 extension ISO/IEC TS 18661-3.
In follow up patches documentation and more tests will be added.
Differential Revision: https://reviews.llvm.org/D33719
llvm-svn: 312781
This is the same assertion as in https://reviews.llvm.org/D25206 that is
triggered when RecordLayoutBuilder tries to compute the size of a field
(for capture "typo_boo" in the test case) whose type hasn't been
deduced.
The fix is to add CorrectDelayedTyposInExpr call to the cases when we
aren't disambiguating between an Obj-C message send and a lambda
expression.
rdar://problem/31760839
Reviewers: rsmith, ahatanak
Reviewed By: arphaman
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D36853
llvm-svn: 311480
Such implicitly declared functions behave as if the enclosing block
contained the declaration extern int name() (C90, 6.3.3.2 Function calls),
thus their names should have block scope (C90, 6.1.2.1 Scope of identifiers).
This patch fixes https://bugs.llvm.org/show_bug.cgi?id=33224
Differential Revision: https://reviews.llvm.org/D33676
llvm-svn: 310616
A refactoring of TemplateIdAnnotation that uses TrailingObjects to create a variably-sized object on the heap.
https://reviews.llvm.org/D31414
Thanks to Aaron B for the review!
llvm-svn: 303594
We were incorrectly setting PrevTokLocation to the first token in the
annotation token instead of the last when consuming it. To fix this without
adding a complex switch to the hot path through ConsumeToken, we now have a
ConsumeAnnotationToken function for consuming annotation tokens in addition
to the other Consume*Token special case functions.
llvm-svn: 303372
- also replace direct equality checks against the ConstantEvaluated enumerator with isConstantEvaluted(), in anticipation of adding finer granularity to the various ConstantEvaluated contexts and reinstating certain restrictions on where lambda expressions can occur in C++17.
- update the clang tablegen backend that uses these Enumerators, and add the relevant scope where needed.
llvm-svn: 299316
Summary:
3.4.6 [basic.lookup.udir] paragraph 1:
In a using-directive or namespace-alias-definition, during the lookup for a namespace-name or for a name in a nested-name-specifier, only namespace names are considered.
Reviewers: rsmith, aaron.ballman
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D30848
llvm-svn: 298126
nested-name-specifier (as the standard appears to require), treat it as the
type specifier 'decltype(auto)' followed by a nested-name-specifier starting
with '::'.
llvm-svn: 294506
We model deduction-guides as functions with a new kind of name that identifies
the template whose deduction they guide; the bulk of this patch is adding the
new name kind. This gives us a clean way to attach an extensible list of guides
to a class template in a way that doesn't require any special handling in AST
files etc (and we're going to need these functions we come to performing
deduction).
llvm-svn: 294266
This change adds a new type node, DeducedTemplateSpecializationType, to
represent a type template name that has been used as a type. This is modeled
around AutoType, and shares a common base class for representing a deduced
placeholder type.
We allow deduced class template types in a few more places than the standard
does: in conditions and for-range-declarators, and in new-type-ids. This is
consistent with GCC and with discussion on the core reflector. This patch
does not yet support deduced class template types being named in typename
specifiers.
llvm-svn: 293207
Under this defect resolution, the injected-class-name of a class or class
template cannot be used except in very limited circumstances (when declaring a
constructor, in a nested-name-specifier, in a base-specifier, or in an
elaborated-type-specifier). This is apparently done to make parsing easier, but
it's a pain for us since we don't know whether a template-id using the
injected-class-name is valid at the point when we annotate it (we don't yet
know whether the template-id will become part of an elaborated-type-specifier).
As a tentative resolution to a perceived language defect, mem-initializer-ids
are added to the list of exceptions here (they generally follow the same rules
as base-specifiers).
When the reference to the injected-class-name uses the 'typename' or 'template'
keywords, we permit it to be used to name a type or template as an extension;
other compilers also accept some cases in this area. There are also a couple of
corner cases with dependent template names that we do not yet diagnose, but
which will also get this treatment.
llvm-svn: 292518
This flag serves no purpose other than to prevent us walking through a type to
check whether it contains an 'auto' specifier; this duplication of information
is error-prone, does not appear to provide any performance benefit, and will
become less practical once we support C++1z deduced class template types and
eventually constrained types from the Concepts TS.
No functionality change intended.
llvm-svn: 291737
This patch fixes an assertion that is triggered when RecordLayoutBuilder
tries to compute the size of a field (for capture "name" in the test
case) whose type hasn't been deduced. The patch fixes the bug by
correcting the typo of the capture initializer after the initializer is
parsed and before setting the expression for the annotation token.
Fixes PR30566.
rdar://problem/23380132
Differential Revision: https://reviews.llvm.org/D25206
llvm-svn: 290156
The code pattern used to implement the token rewriting hack doesn't
interact well with token caching in the pre-processor. As a result,
clang would crash on 'int f(::(id));' while doing a tenative parse of
the contents of the outer parentheses. The original code from PR11852
still doesn't crash the compiler.
This error recovery also often does the wrong thing with member function
pointers. The test case from the original PR doesn't recover the right
way either:
void S::(*pf)() = S::f; // should be 'void (S::*pf)()'
Instead we were recovering as 'void S::*pf()', which is still wrong.
If we still think that users mistakenly parenthesize identifiers in
nested name specifiers, we should change clang to intentionally parse
that form with an error, rather than doing a token rewrite.
Fixes PR26623, but I think there will be many more bugs like this around
token rewriting in the parser.
Reviewers: rsmith, rtrieu
Differential Revision: https://reviews.llvm.org/D25882
llvm-svn: 289273
This saves two pointers from FunctionDecl that were being used for some
rare and questionable C-only functionality. The DeclsInPrototypeScope
ArrayRef was added in r151712 in order to parse this kind of C code:
enum e {x, y};
int f(enum {y, x} n) {
return x; // should return 1, not 0
}
The challenge is that we parse 'int f(enum {y, x} n)' it its own
function prototype scope that gets popped before we build the
FunctionDecl for 'f'. The original change was doing two questionable
things:
1. Saving all tag decls introduced in prototype scope on a TU-global
Sema variable. This is problematic when you have cases like this, where
'x' and 'y' shouldn't be visible in 'f':
void f(void (*fp)(enum { x, y } e)) { /* no x */ }
This patch fixes that, so now 'f' can't see 'x', which is consistent
with GCC.
2. Storing the decls in FunctionDecl in ActOnFunctionDeclarator so that
they could be used in ActOnStartOfFunctionDef. This is just an
inefficient way to move information around. The AST lives forever, but
the list of non-parameter decls in prototype scope is short lived.
Moving these things to the Declarator solves both of these issues.
Reviewers: rsmith
Subscribers: jmolloy, cfe-commits
Differential Revision: https://reviews.llvm.org/D27279
llvm-svn: 289225
Summary:
This is probably the sane place for the attribute to go, but nvcc
specifically rejects it. Other GNU-style attributes are allowed in this
position (although judging from the warning it emits for
host/device/global, those attributes are applied to the lambda's
anonymous struct, not to the function itself).
It would be nice to have a FixIt message here, but doing so, or even
just getting the correct range for the attribute, including its '((' and
'))'s, is apparently Hard.
Reviewers: rnk
Subscribers: cfe-commits, tra
Differential Revision: https://reviews.llvm.org/D25115
llvm-svn: 282911
Summary: There's an overload that we can use to make this a bit cleaner.
Reviewers: rnk
Subscribers: cfe-commits, tra
Differential Revision: https://reviews.llvm.org/D25114
llvm-svn: 282910
Summary: This is ugh, but it makes us compatible with NVCC. Fixes bug 26341.
Reviewers: rnk
Subscribers: cfe-commits, tra
Differential Revision: https://reviews.llvm.org/D25103
llvm-svn: 282879
Functions of Sema that work with building of nested name specifiers have too
many parameters (BuildCXXNestedNameSpecifier already expects 10 arguments).
With this change the information about identifier and its context is packed
into a structure, which is then passes to the semantic functions.
llvm-svn: 277976
decomposition declarations.
There are a couple of things in the wording that seem strange here:
decomposition declarations are permitted at namespace scope (which we partially
support here) and they are permitted as the declaration in a template (which we
reject).
llvm-svn: 276492
No semantic analysis yet.
This is a pain to disambiguate correctly, because the parsing rules for the
declaration form of a condition and of an init-statement are quite different --
for a token sequence that looks like a declaration, we frequently need to
disambiguate all the way to the ')' or ';'.
We could do better here in some cases by stopping disambiguation once we've
decided whether we've got an expression or not (rather than keeping going until
we know whether it's an init-statement declaration or a condition declaration),
by unifying our parsing code for the two types of declaration and moving the
syntactic checks into Sema; if this has a measurable impact on parsing
performance, I'll look into that.
llvm-svn: 274169
-Wfor-loop-analysis warnings for a for-loop with a condition variable. In such
a case, the loop condition variable is modified on each iteration of the loop
by definition.
Original commit message:
Rearrange condition handling so that semantic checks on a condition variable
are performed before the other substatements of the construct are parsed,
rather than deferring them until the end. This allows better error recovery
from semantic errors in the condition, improves diagnostic order, and is a
prerequisite for C++17 constexpr if.
llvm-svn: 273600
are performed before the other substatements of the construct are parsed,
rather than deferring them until the end. This allows better error recovery
from semantic errors in the condition, improves diagnostic order, and is a
prerequisite for C++17 constexpr if.
llvm-svn: 273548
If a closing ')' isn't found for a macro instantiation inside a '[',
the next token is EOF, this leads to crashes if we try to look ahead of
that. This could be triggered whenever trying to parse lambdas or objs
message expressions.
Differential Revision: http://reviews.llvm.org/D20451
rdar://problem/25662647
llvm-svn: 271314
This patch corresponds to reviews:
http://reviews.llvm.org/D15120http://reviews.llvm.org/D19125
It adds support for the __float128 keyword, literals and target feature to
enable it. Based on the latter of the two aforementioned reviews, this feature
is enabled on Linux on i386/X86 as well as SystemZ.
This is also the second attempt in commiting this feature. The first attempt
did not enable it on required platforms which caused failures when compiling
type_traits with -std=gnu++11.
If you see failures with compiling this header on your platform after this
commit, it is likely that your platform needs to have this feature enabled.
llvm-svn: 268898
Since this patch provided support for the __float128 type but disabled it
on all platforms by default, some platforms can't compile type_traits with
-std=gnu++11 since there is a specialization with __float128.
This reverts the patch until D19125 is approved (i.e. we know which platforms
need this support enabled).
llvm-svn: 266460
This patch corresponds to review:
http://reviews.llvm.org/D15120
It adds support for the __float128 keyword, literals and a target feature to
enable it. This support is disabled by default on all targets and any target
that has support for this type is free to add it.
Based on feedback that I've received from target maintainers, this appears to
be the right thing for most targets. I have not heard from the maintainers of
X86 which I believe supports this type. I will subsequently investigate the
impact of enabling this on X86.
llvm-svn: 266186
Support the constexpr specifier on lambda expressions - and support its inference from the lambda call operator's body.
i.e.
auto L = [] () constexpr { return 5; };
static_assert(L() == 5); // OK
auto Implicit = [] (auto a) { return a; };
static_assert(Implicit(5) == 5);
We do not support evaluation of lambda's within constant expressions just yet.
Implementation Strategy:
- teach ParseLambdaExpressionAfterIntroducer to expect a constexpr specifier and mark the invented function call operator's declarator's decl-specifier with it; Have it emit fixits for multiple decl-specifiers (mutable or constexpr) in this location.
- for cases where constexpr is not explicitly specified, have buildLambdaExpr check whether the invented function call operator satisfies the requirements of a constexpr function, by calling CheckConstexprFunctionDecl/Body.
Much obliged to Richard Smith for his patience and his care, in ensuring the code is clang-worthy.
llvm-svn: 264513
Implement lambda capture of *this by copy.
For e.g.:
struct A {
int d = 10;
auto foo() { return [*this] (auto a) mutable { d+=a; return d; }; }
};
auto L = A{}.foo(); // A{}'s lifetime is gone.
// Below is still ok, because *this was captured by value.
assert(L(10) == 20);
assert(L(100) == 120);
If the capture was implicit, or [this] (i.e. *this was captured by reference), this code would be otherwise undefined.
Implementation Strategy:
- amend the parser to accept *this in the lambda introducer
- add a new king of capture LCK_StarThis
- teach Sema::CheckCXXThisCapture to handle by copy captures of the
enclosing object (i.e. *this)
- when CheckCXXThisCapture does capture by copy, the corresponding
initializer expression for the closure's data member
direct-initializes it thus making a copy of '*this'.
- in codegen, when assigning to CXXThisValue, if *this was captured by
copy, make sure it points to the corresponding field member, and
not, unlike when captured by reference, what the field member points
to.
- mark feature as implemented in svn
Much gratitude to Richard Smith for his carefully illuminating reviews!
llvm-svn: 263921
While this won't help fix things like the bug that r260219 addressed, it
seems like good tidy up to have anyway.
(it might be nice if "makeArrayRef" always produced a MutableArrayRef &
let it decay to an ArrayRef when needed - then I'd use that for the
MutableArrayRefs in this patch)
If we had std::dynarray I'd use that instead of unique_ptr+size_t,
ideally (but then it'd have to be threaded down through the Preprocessor
all the way - no idea how painful that would be)
llvm-svn: 260246
Faisal Vali