pointers and block pointers). We use dummy definitions to keep the
invariant that an implicit, used definition has a body; IR generation
will substitute the actual contents, since they can't be represented
as C++.
For the block pointer case, compute the copy-initialization needed to
capture the lambda object in the block, which IR generation will need
later.
llvm-svn: 150645
function, provide a specialized diagnostic that indicates the kind of
special member function (default constructor, copy assignment
operator, etc.) and that it was implicitly deleted. Add a hook where
we can provide more detailed information later.
llvm-svn: 150611
to be core constant expressions (including pointers and references to
temporaries), and makes constexpr calculations Turing-complete. A Turing machine
simulator is included as a testcase.
This opens up the possibilty of removing CCValue entirely, and removing some
copies from the constant evaluator in the process, but that cleanup is not part
of this change.
llvm-svn: 150557
lambda expressions. Because these issue was pulled back from Ready
status at the Kona meeting, we still emit an ExtWarn when using
default arguments for lambda expressions.
llvm-svn: 150519
expression with the original call operator, so that we don't try to
separately instantiate the call operator. Test and tweak a few more
bits for template instantiation of lambda expressions.
llvm-svn: 150440
expressions. This is mostly a simple refact, splitting the main "start
a lambda expression" function into smaller chunks that are driven
either from the parser (Sema::ActOnLambdaExpr) or during AST
transformation (TreeTransform::TransformLambdaExpr). A few minor
interesting points:
- Added new entry points for TreeTransform, so that we can
explicitly establish the link between the lambda closure type in the
template and the lambda closure type in the instantiation.
- Added a bit into LambdaExpr specifying whether it had an explicit
result type or not. We should have had this anyway.
This code is 'lightly' tested.
llvm-svn: 150417
1358, 1360, 1452 and 1453.
- Instantiations of constexpr functions are always constexpr. This removes the
need for separate declaration/definition checking, which is now gone.
- This makes it possible for a constexpr function to be virtual, if they are
only dependently virtual. Virtual calls to such functions are not constant
expressions.
- Likewise, it's now possible for a literal type to have virtual base classes.
A constexpr constructor for such a type cannot actually produce a constant
expression, though, so add a special-case diagnostic for a constructor call
to such a type rather than trying to evaluate it.
- Classes with trivial default constructors (for which value initialization can
produce a fully-initialized value) are considered literal types.
- Classes with volatile members are not literal types.
- constexpr constructors can be members of non-literal types. We do not yet use
static initialization for global objects constructed in this way.
llvm-svn: 150359
id-expression 'x' will compute the type based on the assumption that
'x' will be captured, even if it isn't captured, per C++11
[expr.prim.lambda]p18. There are two related refactors that go into
implementing this:
1) Split out the check that determines whether we should capture a
particular variable reference, along with the computation of the
type of the field, from the actual act of capturing the
variable.
2) Always compute the result of decltype() within Sema, rather than
AST, because the decltype() computation is now context-sensitive.
llvm-svn: 150347
default is '=', and reword the warning about explicitly capturing
'this' in such lambdas to indicate that only explicit capture is
banned.
Introduce Fix-Its for this and other "save the programmer from
themself" rules regarding what can be explicitly captured and what
must be implicitly captured.
llvm-svn: 150256
nested captures. We currently don't get odr-use correct in array
bounds, so that bit is commented out while we sort out what we need to
do.
llvm-svn: 150255
have finished parsing the body, so that name lookup will never find
anything within the closure type. Then, add this operator() and the
conversion function (if available) before completing the class.
llvm-svn: 150252
incomplete class type which has an overloaded operator&, it's now just
unspecified whether the overloaded operator or the builtin is used.
llvm-svn: 150234
[expr.prim.lambda]p4, including the current suggested resolution of
core isue 975, which allows multiple return statements so long as the
types match. ExtWarn when user code is actually making use of this
extension.
llvm-svn: 150168
- Complete the lambda class when we finish the lambda expression
(previously, it was left in the "being completed" state)
- Actually return the LambdaExpr object and bind to the resulting
temporary when needed.
- Detect when cleanups are needed while capturing a variable into a
lambda (e.g., due to default arguments in the copy constructor), and
make sure those cleanups apply for the whole of the lambda
expression.
llvm-svn: 150123
only add 'const' for variables captured by copy in potentially
evaluated expressions of non-mutable lambdas. (The "by copy" part was
missing).
llvm-svn: 150088
the sign bit doesn't have undefined behavior, but a signed left shift of a 1 bit
out of the sign bit still does. As promised to Howard :)
The suppression of the potential constant expression checking in system headers
is also removed, since the problem it was working around is gone.
llvm-svn: 150059
- Capturing variables by-reference and by-copy within a lambda
- The representation of lambda captures
- The creation of the non-static data members in the lambda class
that store the captured variables
- The initialization of the non-static data members from the
captured variables
- Pretty-printing lambda expressions
There are a number of FIXMEs, both explicit and implied, including:
- Creating a field for a capture of 'this'
- Improved diagnostics for initialization failures when capturing
variables by copy
- Dealing with temporaries created during said initialization
- Template instantiation
- AST (de-)serialization
- Binding and returning the lambda expression; turning it into a
proper temporary
- Lots and lots of semantic constraints
- Parameter pack captures
llvm-svn: 149977
value of class type, look for a unique conversion operator converting to
integral or unscoped enumeration type and use that. Implements [expr.const]p5.
Sema::VerifyIntegerConstantExpression now performs the conversion and returns
the converted result. Some important callers of Expr::isIntegralConstantExpr
have been switched over to using it (including all of those required for C++11
conformance); this switch brings a side-benefit of improved diagnostics and, in
several cases, simpler code. However, some language extensions and attributes
have not been moved across and will not perform implicit conversions on
constant expressions of literal class type where an ICE is required.
In passing, fix static_assert to perform a contextual conversion to bool on its
argument.
llvm-svn: 149776
* support the gcc __builtin_constant_p() ? ... : ... folding hack in C++11
* check for unspecified values in pointer comparisons and pointer subtractions
llvm-svn: 149578
This is a mess. According to the C++11 standard, pointer subtraction only has
undefined behavior if the difference of the array indices does not fit into a
ptrdiff_t.
However, common implementations effectively perform a char* subtraction first,
and then divide the result by the element size, which can cause overflows in
some cases. Those cases are not considered to be undefined behavior by this
change; perhaps they should be.
llvm-svn: 149490
- Actually building the var -> capture mapping properly (there was an off-by-one error)
- Keeping track of the source location of each capture
- Minor QoI improvements, e.g, highlighing the prior capture if
there are multiple captures, pointing at the variable declaration we
found if we reject it.
As part of this, add standard citations for the various semantic
checks we perform, and note where we're not performing those checks as
we should.
llvm-svn: 149462
values and non-type template arguments of integral and enumeration types.
This change causes some legal C++98 code to no longer compile in C++11 mode, by
enforcing the C++11 rule that narrowing integral conversions are not permitted
in the final implicit conversion sequence for the above cases.
llvm-svn: 148439
not integer constant expressions. In passing, fix the 'folding is an extension'
diagnostic to not claim we're accepting the code, since that's not true in
-pedantic-errors mode, and add this diagnostic to -Wgnu.
llvm-svn: 148209
pointer-arithmetic-related undefined behavior and unspecified results. We
continue to fold such values, but now notice they aren't constant expressions.
llvm-svn: 147659
Also temporarily remove the assumption from IR gen that we can emit IR for every
constant we can fold, since it isn't currently true in C++11, to fix PR11676.
Original comment from r147271:
constexpr: perform zero-initialization prior to / instead of performing a
constructor call when appropriate. Thanks to Eli for spotting this.
llvm-svn: 147384
Split out a new ExpressionEvaluationContext flag for this case, and don't treat
it as unevaluated in C++11. This fixes some crash-on-invalids where we would
allow references to class members in potentially-evaluated constant expressions
in static member functions, and also fixes half of PR10177.
The fix to PR10177 exposed a case where template instantiation failed to provide
a source location for a diagnostic, so TreeTransform has been tweaked to supply
source locations when transforming a type. The source location is still not very
good, but MarkDeclarationsReferencedInType would need to operate on a TypeLoc to
improve it further.
Also fix MarkDeclarationReferenced in C++98 mode to trigger instantiation for
static data members of class templates which are used in constant expressions.
This fixes a link-time problem, but we still incorrectly treat the member as
non-constant. The rest of the fix for that issue is blocked on PCH support for
early-instantiated static data members, which will be added in a subsequent
patch.
llvm-svn: 146955
variable is initialized by a non-constant expression, and pass in the variable
being declared so that earlier-initialized fields' values can be used.
Rearrange VarDecl init evaluation to make this possible, and in so doing fix a
long-standing issue in our C++ constant expression handling, where we would
mishandle cases like:
extern const int a;
const int n = a;
const int a = 5;
int arr[n];
Here, n is not initialized by a constant expression, so can't be used in an ICE,
even though the initialization expression would be an ICE if it appeared later
in the TU. This requires computing whether the initializer is an ICE eagerly,
and saving that information in PCH files.
llvm-svn: 146856
fails within a call to a constexpr function. Add -fconstexpr-backtrace-limit
argument to driver and frontend, to control the maximum number of notes so
produced (default 10). Fix APValue printing to be able to pretty-print all
APValue types, and move the testing for this functionality from a unittest to
a -verify test now that it's visible in clang's output.
llvm-svn: 146749
freebsd bots happy. In the longer term, we should have a mechanism for moving
constexpr recursion off the call stack, to support the default limit of 512
suggested by the standard.
llvm-svn: 146596
through varargs. This only happens when we're in an unevaluated
context, where we don't want to trigger an error anyway. Fixes PR11131
/ <rdar://problem/10288375>.
llvm-svn: 141986
and DefaultFunctionArrayLvalueConversion. To prevent
significant regression for should-this-be-a-call fixits,
and to repair some such regression from the introduction of
bound member placeholders, make those placeholder checks
try to build calls appropriately. Harden the build-a-call
logic while we're at it.
llvm-svn: 141738
that the unevaluated subexpressions of &&, ||, and ? : are not
considered when determining whether the expression is a constant
expression. Also, turn the "used in its own initializer" warning into
a runtime-behavior warning, so that it doesn't fire when a variable is
used as part of an unevaluated subexpression of its own initializer.
Fixes PR9999.
llvm-svn: 131968
overload, so that we actually do the resolution for full expressions
and emit more consistent, useful diagnostics. Also fixes an IRGen
crasher, where Sema wouldn't diagnose a resolvable bound member
function template-id used in a full-expression (<rdar://problem/9108698>).
llvm-svn: 127747
a scoped enumeration type to an integral or floating type,
properly. There was an over-eager assertion, and it was missing the
floating-point case.
Fixes PR9107/<rdar://problem/8937402>.
llvm-svn: 125825
- BlockDeclRefExprs always store VarDecls
- BDREs no longer store copy expressions
- BlockDecls now store a list of captured variables, information about
how they're captured, and a copy expression if necessary
With that in hand, change IR generation to use the captures data in
blocks instead of walking the block independently.
Additionally, optimize block layout by emitting fields in descending
alignment order, with a heuristic for filling in words when alignment
of the end of the block header is insufficient for the most aligned
field.
llvm-svn: 125005
derived-to-base cast that also casts away constness (one of the cases
for static_cast followed by const_cast) would be treated as a bit-cast
rather than a derived-to-base class, causing miscompiles and
heartburn.
Fixes <rdar://problem/8913298>.
llvm-svn: 124340
Remove -faccess-control from -cc1; add -fno-access-control.
Make the driver pass -fno-access-control by default.
Update a bunch of tests to be correct under access control.
llvm-svn: 100880
how we find the operator delete that matches withe operator new we
found in a C++ new-expression.
This will also need CodeGen support. On a happy note, we're now a
"nans" away from building tramp3d-v4.
llvm-svn: 97209
Sema::ActOnUninitializedDecl over to InitializationSequence (with
default initialization), eliminating redundancy. More importantly, we
now check that a const definition in C++ has an initilizer, which was
an #if 0'd code for many, many months. A few other tweaks were needed
to get everything working again:
- Fix all of the places in the testsuite where we defined const
objects without initializers (now that we diagnose this issue)
- Teach instantiation of static data members to find the previous
declaration, so that we build proper redeclaration
chains. Previously, we had the redeclaration chain but built it
too late to be useful, because...
- Teach instantiation of static data member definitions not to try
to check an initializer if a previous declaration already had an
initializer. This makes sure that we don't complain about static
const data members with in-class initializers and out-of-line
definitions.
- Move all of the incomplete-type checking logic out of
Sema::FinalizeDeclaratorGroup; it makes more sense in
ActOnUnitializedDecl.
There may still be a few places where we can improve these
diagnostics. I'll address that as a separate commit.
llvm-svn: 95657
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
Douglas Gregor