For an init capture, process the initialization expression
right away. For lambda init-captures such as the following:
const int x = 10;
auto L = [i = x+1](int a) {
return [j = x+2,
&k = x](char b) { };
};
keep in mind that each lambda init-capture has to have:
- its initialization expression executed in the context
of the enclosing/parent decl-context.
- but the variable itself has to be 'injected' into the
decl-context of its lambda's call-operator (which has
not yet been created).
Each init-expression is a full-expression that has to get
Sema-analyzed (for capturing etc.) before its lambda's
call-operator's decl-context, scope & scopeinfo are pushed on their
respective stacks. Thus if any variable is odr-used in the init-capture
it will correctly get captured in the enclosing lambda, if one exists.
The init-variables above are created later once the lambdascope and
call-operators decl-context is pushed onto its respective stack.
Since the lambda init-capture's initializer expression occurs in the
context of the enclosing function or lambda, therefore we can not wait
till a lambda scope has been pushed on before deciding whether the
variable needs to be captured. We also need to process all
lvalue-to-rvalue conversions and discarded-value conversions,
so that we can avoid capturing certain constant variables.
For e.g.,
void test() {
const int x = 10;
auto L = [&z = x](char a) { <-- don't capture by the current lambda
return [y = x](int i) { <-- don't capture by enclosing lambda
return y;
}
};
If x was not const, the second use would require 'L' to capture, and
that would be an error.
Make sure TranformLambdaExpr is also aware of this.
Patch approved by Richard (Thanks!!)
http://llvm-reviews.chandlerc.com/D2092
llvm-svn: 196454
nested-name-specifier, rather than crashing. (In fact, reject all
literal-operator-ids that have a non-namespace nested-name-specifier). The
grammar doesn't allow these in some cases, and in other cases does allow them
but instantiation will always fail.
llvm-svn: 196443
See http://lists.cs.uiuc.edu/pipermail/cfe-dev/2013-November/033369.html for discussion on cfe-dev.
This fix explicitly checks whether we are within the declcontext of a lambda's call operator - which is what I had intended to be true (and assumed would be true if getCurLambda returns a valid pointer) before checking whether a lambda can capture the potential-captures of the innermost lambda.
A deeper fix (that addresses why getCurLambda() returns a valid pointer when perhaps it shouldn't?) - as proposed by Richard Smith in http://llvm.org/bugs/show_bug.cgi?id=17877 - has been suggested as a FIXME.
Patch was LGTM'd by Richard (just barely :)
http://llvm-reviews.chandlerc.com/D2144
llvm-svn: 194448
Both Richard and I felt that the current wording in the working paper needed some tweaking - Please see http://llvm-reviews.chandlerc.com/D2035 for additional context and references to core-reflector messages that discuss wording tweaks.
What is implemented is what we had intended to specify in Bristol; but, recently felt that the specification might benefit from some tweaking and fleshing.
As a rough attempt to explain the semantics: If a nested lambda with a default-capture names a variable within its body, and if the enclosing full expression that contains the name of that variable is instantiation-dependent - then an enclosing lambda that is capture-ready (i.e. within a non-dependent context) must capture that variable, if all intervening nested lambdas can potentially capture that variable if they need to, and all intervening parent lambdas of the capture-ready lambda can and do capture the variable.
Of note, 'this' capturing is also currently underspecified in the working paper for generic lambdas. What is implemented here is if the set of candidate functions in a nested generic lambda includes both static and non-static member functions (regardless of viability checking - i.e. num and type of parameters/arguments) - and if all intervening nested-inner lambdas between the capture-ready lambda and the function-call containing nested lambda can capture 'this' and if all enclosing lambdas of the capture-ready lambda can capture 'this', then 'this' is speculatively captured by that capture-ready lambda.
Hopefully a paper for the C++ committee (that Richard and I had started some preliminary work on) is forthcoming.
This essentially makes generic lambdas feature complete, except for known bugs. The more prominent ones (and the ones I am currently aware of) being:
- generic lambdas and init-captures are broken - but a patch that fixes this is already in the works ...
- nested variadic expansions such as:
auto K = [](auto ... OuterArgs) {
vp([=](auto ... Is) {
decltype(OuterArgs) OA = OuterArgs;
return 0;
}(5)...);
return 0;
};
auto M = K('a', ' ', 1, " -- ", 3.14);
currently cause crashes. I think I know how to fix this (since I had done so in my initial implementation) - but it will probably take some work and back & forth with Doug and Richard.
A warm thanks to all who provided feedback - and especially to Doug Gregor and Richard Smith for their pivotal guidance: their insight and prestidigitation in such matters is boundless!
Now let's hope this commit doesn't upset the buildbot gods ;)
Thanks!
llvm-svn: 194188
would be deleted are still declared, but are ignored by overload resolution.
Also, don't delete such members if a subobject has no corresponding move
operation and a non-trivial copy. This causes us to implicitly declare move
operations in more cases, but risks move-assigning virtual bases multiple
times in some circumstances (a warning for that is to follow).
llvm-svn: 193969
Summary: Some MS headers use these features.
Reviewers: rnk, rsmith
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1948
llvm-svn: 192936
This is a fix to PR12778: in erroneous code an allocation function
can be declared with no arguments, quering the first argument in this case
causes assertion violation.
llvm-svn: 190751
Summary:
__uuidof on templated types should exmaine if any of its template
parameters have a uuid declspec. If exactly one does, then take it.
Otherwise, issue an appropriate error.
Reviewers: rsmith, thakis, rnk
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1419
llvm-svn: 190240
In addition to storing more useful information in the AST, this
fixes a semantic check in template instantiation which checks whether
the l-paren location is valid.
Fixes PR16903.
llvm-svn: 188495
global allocation or deallocation function, that should not cause that global
allocation or deallocation function to become unavailable.
llvm-svn: 186270
clang would incorrectly not allow the following:
int x = true ? (throw 1) : 2;
The problem exists because we don't see beyond the parens.
This, in turn, causes us to believe that we are choosing between void
and int which we diagnose as an error.
Instead, allow clang to see the 'throw' inside the parens.
llvm-svn: 183085
* Treat _Atomic(T) as a literal type if T is a literal type.
* Evaluate expressions of this type properly.
* Fix a lurking bug where we built completely bogus ASTs for converting to
_Atomic types in C++ in some cases, caught by the tests for this change.
llvm-svn: 182541
common function. The C++1y contextual implicit conversion rules themselves are
not yet implemented, however.
This also fixes a subtle bug where template instantiation context notes were
dropped for diagnostics coming from conversions for integral constant
expressions -- we were implicitly slicing a SemaDiagnosticBuilder into a
DiagnosticBuilder when producing these diagnostics, and losing their context
notes in the process.
llvm-svn: 182406
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
the actual parser and support arbitrary id-expressions.
We're actually basically set up to do arbitrary expressions here
if we wanted to.
Assembly operands permit things like A::x to be written regardless
of language mode, which forces us to embellish the evaluation
context logic somewhat. The logic here under template instantiation
is incorrect; we need to preserve the fact that an expression was
unevaluated. Of course, template instantiation in general is fishy
here because we have no way of delaying semantic analysis in the
MC parser. It's all just fishy.
I've also fixed the serialization of MS asm statements.
This commit depends on an LLVM commit.
llvm-svn: 180976
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
Add a CapturedStmt.h similar to Lambda.h to reduce the typing required to get
to the CapturedRegionKind enum. This also allows codegen to access this enum
without including Sema/ScopeInfo.h.
Also removes some duplicated code for capturing 'this' between CapturedStmt and
Lambda.
Differential Revision: http://llvm-reviews.chandlerc.com/D712
llvm-svn: 180710
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
Add CapturedDecl to be the DeclContext for CapturedStmt, and perform semantic
analysis. Currently captures all variables by reference.
TODO: templates
Author: Ben Langmuir <ben.langmuir@intel.com>
Differential Revision: http://llvm-reviews.chandlerc.com/D433
llvm-svn: 179618
http://lab.llvm.org:8011/builders/clang-x86_64-darwin10-gdb went back green
before it processed the reverted 178663, so it could not have been the culprit.
Revert "Revert 178663."
This reverts commit 4f8a3eb2ce5d4ba422483439e20c8cbb4d953a41.
llvm-svn: 178682
For variables and functions clang used to store two storage classes. The one
"as written" in the code and a patched one, which, for example, propagates
static to the following decls.
This apparently is from the days clang lacked linkage computation. It is now
redundant and this patch removes it.
llvm-svn: 178663
MarkMemberReferenced instead of marking functions referenced directly. An audit
of callers to MarkFunctionReferenced and DiagnoseUseOfDecl also caused a few
other changes:
* don't mark functions odr-used when considering them for an initialization
sequence. Do mark them referenced though.
* the function nominated by the cleanup attribute should be diagnosed.
* operator new/delete should be diagnosed when building a 'new' expression.
llvm-svn: 174951
expressions which have undefined behavior due to multiple unsequenced
modifications or an unsequenced modification and use of a variable.
llvm-svn: 172690
ActOnFinishFullExpr that some of its checks only apply to discarded-value
expressions. This adds missing checks for unexpanded variadic template
parameter packs to a handful of constructs.
llvm-svn: 172485
copy-list-initialization (and doesn't add an additional copy step):
Fill in the ListInitialization bit when creating a CXXConstructExpr. Use it
when instantiating initializers in order to correctly handle instantiation of
copy-list-initialization. Teach TreeTransform that function arguments are
initializations, and so need this special treatment too. Finally, remove some
hacks which were working around SubstInitializer's shortcomings.
llvm-svn: 170489
This does limit these typedefs to being sequences, but no current usage
requires them to be contiguous (we could expand this to a more general
iterator pair range concept at some point).
Also, it'd be nice if SmallVector were constructible directly from an ArrayRef
but this is a bit tricky since ArrayRef depends on SmallVectorBaseImpl for the
inverse conversion. (& generalizing over all range-like things, while nice,
would require some nontrivial SFINAE I haven't thought about yet)
llvm-svn: 170482
Remove pre-standard restriction on explicitly-defaulted copy constructors with
'incorrect' parameter types, and instead just make those special members
non-trivial as the standard requires.
This required making CXXRecordDecl correctly handle classes which have both a
trivial and a non-trivial special member of the same kind.
This also fixes PR13217 by reimplementing DiagnoseNontrivial in terms of the
new triviality computation technology.
llvm-svn: 169667
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
initialization, don't rebuild it. Remove a couple of hacks which were trying to
work around this. Fix the special case for one-argument CXXConstructExprs to
not apply if the one argument is a default argument.
llvm-svn: 168582
It may become a dangling pointer if the underlying SmallVector reallocates.
Sadly the testcase is really large and doesn't reduce well because of
SmallVector's reallocation patterns.
Fixes PR14336.
llvm-svn: 168045
Spent longer than reasonable looking for a nice way to test this & decided to
give up for now. Open to suggestions/requests. Richard Smith suggested adding
something to ASTMatchers but it wasn't readily apparent how to test this with
that.
llvm-svn: 167507
Clang will now honor the FP_CONTRACT pragma and emit LLVM
fmuladd intrinsics for expressions of the form A * B + C (when they occur in a
single statement).
llvm-svn: 164989
integral promotions to both its underlying type and to its underlying type's
promoted type. This matters now that boolean conversions aren't permitted in
converted constant expressions (a la DR1407): an enumerator with a fixed
underlying type of bool still can be.
llvm-svn: 163841
A couple of missing "RequireNonAbstractType" calls in conditional operator
handling. I looked for opportunities to tie this check in to all relevant
callers of PerformCopyInitialization (couldn't be all callers since this is
called for base subobject copying too, where it's acceptable to copy abstract
types) but the callers varied too much & in many cases had substantial code
or conditionals on the RequireNonAbstractType call, the
PerformCopyInitialization call, or the code between the two calls.
llvm-svn: 163555
A conditional operator between glvalues of types cv1 T and cv2 T produces a
glvalue if the expressions are of the same value kind and one of cv1 and cv2
is a subset of the other.
A conditional operator between two null pointer constants is permitted if one
of them is of type std::nullptr_t.
llvm-svn: 161476
and the other is a glvalue of class type, don't forget to copy-initialize a
temporary when performing the lvalue-to-rvalue conversion on the glvalue.
Strangely, DefaultLvalueConversions misses this part of the lvalue-to-rvalue
conversions.
llvm-svn: 161450
expressions to have complete return types (or accessible destructors). If the
return type is required to be complete for some other reason (for instance, if
it is needed by overload resolution), then it will still be required to be
complete. This is apparently required in order to parse a MSVC11 header.
llvm-svn: 160924
a defaulted special member function until the exception specification is needed
(using the same criteria used for the delayed instantiation of exception
specifications for function temploids).
EST_Delayed is now EST_Unevaluated (using 1330's terminology), and, like
EST_Uninstantiated, carries a pointer to the FunctionDecl which will be used to
resolve the exception specification.
This is enabled for all C++ modes: it's a little faster in the case where the
exception specification isn't used, allows our C++11-in-C++98 extensions to
work, and is still correct for C++98, since in that mode the computation of the
exception specification can't fail.
The diagnostics here aren't great (in particular, we should include implicit
evaluation of exception specifications for defaulted special members in the
template instantiation backtraces), but they're not much worse than before.
Our approach to the problem of cycles between in-class initializers and the
exception specification for a defaulted default constructor is modified a
little by this change -- we now reject any odr-use of a defaulted default
constructor if that constructor uses an in-class initializer and the use is in
an in-class initialzer which is declared lexically earlier. This is a closer
approximation to the current draft solution in core issue 1351, but isn't an
exact match (but the current draft wording isn't reasonable, so that's to be
expected).
llvm-svn: 160847
type traits that assignment to/construction of a lifetime-qualified
object under ARC is *not* trivial. Fixes <rdar://problem/11738725>.
llvm-svn: 159401
Faisal Vali