Summary: @rsmith Is there a better place to put this test?
Reviewers: GorNishanov, rsmith
Reviewed By: GorNishanov
Subscribers: cfe-commits, rsmith
Differential Revision: https://reviews.llvm.org/D33660
llvm-svn: 304331
Summary:
The expression `await_ready` is required to be contextually convertible to bool and `await_suspend` must be a prvalue of either `void` or `bool`.
This patch adds diagnostics for when those requirements are violated.
It also correctly performs the contextual conversion to bool on the result of `await_ready`
Reviewers: GorNishanov, rsmith
Reviewed By: GorNishanov
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D33625
llvm-svn: 304094
We were leaving the SubobjectDesignator in a surprising situation, where
it was allegedly valid but didn't actually refer to a type. This caused
a crash later on.
This patch fills out the SubobjectDesignator with the pointee type (as
happens in other evaluations of constant pointers) so that we don't
crash later.
llvm-svn: 303957
member function" context notes to registering an entry on the context stack.
Also reorder the steps within defining special members to be consistent.
This has a few benefits: if multiple diagnostics are produced while checking
such a member, the note is now attached to the first such diagnostic rather
than the last, this prepares us for persisting these diagnostics between the
point at which we require the implicit instantiation of a template and the
point at which that instantiation is actually performed, and this fixes some
cases where we would fail to produce a full note stack leading back to user
code in the case of such a diagnostic.
The reordering exposed a case where we could recursively attempt to define a
defaulted destructor while we're already defining one (and other such cases
also appear to be possible, with or without this change), so this change also
reuses the "willHaveBody" flag on function declarations to track that we're in
the middle of synthesizing a body for the function and bails out if we try to
define a function that we're already defining.
llvm-svn: 303930
Summary:
According to the PDTS it's perfectly legal to have a promise type that defines neither `return_value` nor `return_void`. However a coroutine that uses such a promise type will almost always have UB, because it can never `co_return`.
This patch changes Clang to diagnose such cases as an error. It also cleans up some of the diagnostic messages relating to member lookup in the promise type.
Reviewers: GorNishanov, rsmith
Reviewed By: GorNishanov
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D33534
llvm-svn: 303868
Summary:
This patch fixes a number of issues with the analysis warnings emitted when a coroutine may reach the end of the function w/o returning.
* Fix bug where coroutines with `return_value` are incorrectly diagnosed as missing `co_return`'s.
* Rework diagnostic message to no longer say "non-void coroutine", because that implies the coroutine doesn't have a void return type, which it might. In this case a non-void coroutine is one who's promise type does not contain `return_void()`
As a side-effect of this patch, coroutine bodies that contain an invalid coroutine promise objects are marked as invalid.
Reviewers: GorNishanov, rsmith, aaron.ballman, majnemer
Reviewed By: GorNishanov
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D33532
llvm-svn: 303831
Summary: Now we helpfully provide a note pointing at the promise_type in question.
Reviewers: EricWF, GorNishanov
Reviewed By: GorNishanov
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D33481
llvm-svn: 303752
C++14 added user-defined literal support for complex numbers so that you can
write something like "complex<double> val = 2i". However, there is an existing
GNU extension supporting this syntax and interpreting the result as a _Complex
type.
This changes parsing so that such literals are interpreted in terms of C++14's
operators if an overload is present but otherwise falls back to the original
GNU extension.
llvm-svn: 303694
Summary:
If unhandled_exception member function is present in the coroutine promise,
wrap the body of the coroutine in:
```
try {
body
} catch(...) { promise.unhandled_exception(); }
```
Reviewers: EricWF, rnk, rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D31692
llvm-svn: 303583
Summary:
1. build declaration of the gro local variable that keeps the result of get_return_object.
2. build return statement returning the gro variable
3. emit them during CodeGen
4. sema and CodeGen tests updated
Reviewers: EricWF, rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D31646
llvm-svn: 303573
This patch ensures that clang processes the expression-nodes that are generated when disambiguating between types and expressions within template arguments as constant-expressions by installing the ConstantEvaluated ExpressionEvaluationContext just before attempting the disambiguation - and then making sure that Context carries through into ParseConstantExpression (by refactoring it out into a function that does not create its own EvaluationContext: ParseConstantExpressionInExprEvalContext)
Note, prior to this patch, trunk would correctly disambiguate and identify the expression as an expression - and while it would annotate the token with the expression - it would fail to complete the odr-use processing (specifically, failing to trigger Sema::UpdateMarkingForLValueToRValue as is done for all Constant Expressions, which would remove it from being considered odr-used). By installing the ConstantExpression Evaluation Context prior to disambiguation, and making sure it carries though, we ensure correct processing of the expression-node.
For e.g:
template<int> struct X { };
void f() {
const int N = 10;
X<N> x; // should be OK.
[] { return X<N>{}; }; // Should be OK - no capture - but clang errors!
}
See a related bug: https://bugs.llvm.org//show_bug.cgi?id=25627
In summary (and reiteration), the fix is as follows:
- Remove the EnteredConstantEvaluatedContext action from ParseTemplateArgumentList (relying on ParseTemplateArgument getting it right)
- Add the EnteredConstantEvaluatedContext action just prior to undergoing the disambiguating parse, and if the parse succeeds for an expression, carry the context though into a refactored version of ParseConstantExpression that does not create its own ExpressionEvaluationContext.
See https://reviews.llvm.org/D31588 for additional context regarding some of the more fragile and complicated approaches attempted, and Richard's feedback that eventually shaped the simpler and more robust rendition that is being committed.
Thanks Richard!
llvm-svn: 303492
inferring based on the current module at the point of creation.
This should result in no functional change except when building a preprocessed
module (or more generally when using #pragma clang module begin/end to switch
module in the middle of a file), in which case it allows us to correctly track
the owning module for declarations. We can't map from FileID to module in the
preprocessed module case, since all modules would have the same FileID.
There are still a couple of remaining places that try to infer a module from a
source location; I'll clean those up in follow-up changes.
llvm-svn: 303322
This commit fixes a bug that's tracked by PR 10758 and duplicates like PR 30343.
The bug causes clang to crash with a stack overflow while recursing infinitely
trying to perform copy-initialization on a type without a copy constructor but
with a constructor that accepts another type that can be constructed using the
original type.
The commit fixes this bug by detecting the recursive behavior and failing
correctly with an appropriate error message. It also tries to provide a
meaningful diagnostic note about the constructor which leads to this behavior.
rdar://28483944
Differential Revision: https://reviews.llvm.org/D25051
llvm-svn: 303156
https://bugs.llvm.org/show_bug.cgi?id=32933
Turns out clang wasn't really handling vla's (*) in C++11's for-range entirely correctly.
For e.g. This would lead to generation of buggy IR:
void foo(int b) {
int vla[b];
b = -1; // This store would affect the '__end = vla + b'
for (int &c : vla)
c = 0;
}
Additionally, code-gen would get confused when VLA's were reference-captured by lambdas, and then used in a for-range, which would result in an attempt to generate IR for '__end = vla + b' within the lambda's body - without any capture of 'b' - hence the assertion.
This patch modifies clang, so that for VLA's it translates the end pointer approximately into:
__end = __begin + sizeof(vla)/sizeof(vla->getElementType())
As opposed to the __end = __begin + b;
I considered passing a magic value into codegen - or having codegen special case the '__end' variable when it referred to a variably-modified type, but I decided against that approach, because it smelled like I would be increasing a complicated form of coupling, that I think would be even harder to maintain than the above approach (which can easily be optimized (-O1) to refer to the run-time bound that was calculated upon array's creation or copied into the lambda's closure object).
(*) why oh why gcc would you enable this by default?! ;)
llvm-svn: 303026
This patch teaches clang to perform implicit scalar to vector conversions
when one of the operands of a binary vector expression is a scalar which
can be converted to the element type of the vector without truncation
following GCC's implementation.
If the (constant) scalar is can be casted safely, it is implicitly casted to the
vector elements type and splatted to produce a vector of the same type.
Contributions from: Petar Jovanovic
Reviewers: bruno, vkalintiris
Differential Revision: https://reviews.llvm.org/D25866
llvm-svn: 302935
Diagnostics related to redefinition errors that point to the same header
file do not provide much information that helps users fixing the issue.
- In the modules context, it usually happens because of non modular
includes.
- When modules aren't involved it might happen because of the lack of
header guards.
Enhance diagnostics in these scenarios.
Differential Revision: https://reviews.llvm.org/D28832
rdar://problem/31669175
llvm-svn: 302765
When an undeclared identifier in a context that requires a type is followed by
'<', only look for type templates when typo-correcting, tweak the diagnostic
text to say that a template name (not a type name) was undeclared, and parse
the template arguments when recovering from the error.
llvm-svn: 302732
The heuristic that we use here is:
* the left-hand side must be a simple identifier or a class member access
* the right-hand side must be '<' followed by either a '>' or by a type-id that
cannot be an expression (in particular, not followed by '(' or '{')
* there is a '>' token matching the '<' token
The second condition guarantees the expression would otherwise be ill-formed.
If we're confident that the user intended the name before the '<' to be
interpreted as a template, diagnose the fact that we didn't interpret it
that way, rather than diagnosing that the template arguments are not valid
expressions.
llvm-svn: 302615
This fixes the bug: https://bugs.llvm.org/show_bug.cgi?id=32638
int main()
{
[](auto x) noexcept(noexcept(x)) { } (0);
}
In the above code, prior to this patch, when substituting into the noexcept expression, i.e. transforming the DeclRefExpr that represents 'x' - clang attempts to capture 'x' because Sema's CurContext is still pointing to the pattern FunctionDecl (i.e. the templated-decl set in FinishTemplateArgumentDeduction) which does not match the substituted 'x's DeclContext, which leads to an attempt to capture and an assertion failure.
We fix this by adjusting Sema's CurContext to point to the substituted FunctionDecl under which the noexcept specifier's argument should be transformed, and so the ParmVarDecl that 'x' refers to has the same declcontext and no capture is attempted.
I briefly investigated whether the SwitchContext should occur right after VisitMethodDecl creates the new substituted FunctionDecl, instead of only during instantiating the exception specification - but seeing no other code that seemed to rely on that, I decided to leave it just for the duration of the exception specification instantiation.
llvm-svn: 302507
We were sometimes doing a function->pointer conversion in
Sema::CheckPlaceholderExpr, which isn't the job of CheckPlaceholderExpr.
So, when we saw typeof(OverloadedFunctionName), where
OverloadedFunctionName referenced a name with only one function that
could have its address taken, we'd give back a function pointer type
instead of a function type. This is incorrect.
I kept the logic for doing the function pointer conversion in
resolveAndFixAddressOfOnlyViableOverloadCandidate because it was more
consistent with existing ResolveAndFix* methods.
llvm-svn: 302506
Add an opt-in warning that fires when 0 is used as a null pointer.
gcc has this warning, and there's some demand for it.
https://reviews.llvm.org/D32914
llvm-svn: 302247
Summary:
First, getCurFunction looks through blocks and lambdas, which is wrong.
Inside a lambda, va_start should refer to the lambda call operator
prototype. This fixes PR32737.
Second, we shouldn't use any of the getCur* methods, because they look
through contexts that we don't want to look through (EnumDecl,
CapturedStmtDecl). We can use CurContext directly as the calling
context.
Finally, this code assumed that CallExprs would never appear outside of
code contexts (block, function, obj-c method), which is wrong. Struct
member initializers are an easy way to create and parse exprs in a
non-code context.
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D32761
llvm-svn: 302188
- this is added just for completeness sake (though the general case should be represented by the test added in the revision to that patch: https://reviews.llvm.org/rL301972 )
llvm-svn: 301973
When computing the appropriate cv-qualifiers for the 'this' capture, we have to examine each enclosing lambda - but when using the FunctionScopeInfo stack we have to ensure that the lambda below (outer) is the decl-context of the closure-class of the current lambda.
https://bugs.llvm.org/show_bug.cgi?id=32831
This patch was initially committed here: https://reviews.llvm.org/rL301735
Then reverted here: https://reviews.llvm.org/rL301916
The issue with the original patch was a failure to check that the closure type has been created within the LambdaScopeInfo before querying its DeclContext - instead of just assuming it has (silly!). A reduced example such as this highlights the problem:
struct X {
int data;
auto foo() { return [] { return [] -> decltype(data) { return 0; }; }; }
};
When 'data' within decltype(data) tries to determine the type of 'this', none of the LambdaScopeInfo's have their closure types created at that point.
llvm-svn: 301972
handling of constexprs with unknown bounds.
This triggers a corner case of the language where it's not yet clear
whether this should be an error:
struct A {
static void *const a[];
static void *const b[];
};
constexpr void *A::a[] = {&b[0]};
constexpr void *A::b[] = {&a[0]};
When discovering the initializer for A::a, the bounds of A::b aren't known yet.
It is unclear whether warning about errors should be deferred until the end of
the translation unit, possibly resolving errors that can be resolved. In
practice, the compiler can know the bounds of all arrays in this example.
Credits for reproducers and explanation go to Richard Smith. Richard, please
add more info in case my explanation is wrong.
llvm-svn: 301963
It leads to clang crashing, e.g. on this short code fragment (added to
test/SemaCXX/warn-thread-safety-parsing.cpp):
class SomeClass {
public:
void foo() {
auto l = [this] { auto l = [] EXCLUSIVE_LOCKS_REQUIRED(mu_) {}; };
}
Mutex mu_;
};
llvm-svn: 301916
The fix is that ExprEvaluatorBase::VisitInitListExpr should handle transparent exprs instead of exprs with one element. Fixing that uncovers one testcase failure because the AST for "constexpr _Complex float test2 = {1};" is wrong (the _Complex prvalue should not be const-qualified), and a number of test failures in test/OpenMP where the captured stmt contains an InitListExpr that is in syntactic form.
llvm-svn: 301891
Do not spuriously reject constexpr functions that access elements of an array
of unknown bound; this may later become valid once the bound is known. Permit
array-to-pointer decay on such arrays, but disallow pointer arithmetic (since
we do not know whether it will have defined behavior).
The standard is not clear on how this should work, but this seems to be a
decent answer.
Patch by Robert Haberlach!
llvm-svn: 301822
When computing the appropriate cv-qualifiers for the 'this' capture, we have to examine each enclosing lambda - but when using the FunctionScopeInfo stack we have to ensure that the lambda below (outer) is the decl-context of the closure-class of the current lambda.
https://bugs.llvm.org/show_bug.cgi?id=32831
llvm-svn: 301735
The previous algorithm processed one character at a time, which is very
painful on a modern CPU. Replace it with xxHash64, which both already
exists in the codebase and is fairly fast.
Patch from Scott Smith!
Differential Revision: https://reviews.llvm.org/D32509
llvm-svn: 301487
isMicrosoftMissingTypename() uses a Type pointer without first checking
that it's non-null. PR32750 reports a case where the pointer is in fact
null. This patch adds in a defensive check and a regression test.
Differential Revision: https://reviews.llvm.org/D32519
llvm-svn: 301420
This switches from the prototype syntax in P0273R0 ('module' and 'module
implementation') to the consensus syntax 'export module' and 'module'.
In passing, drop the "module declaration must be first" enforcement, since EWG
seems to have changed its mind on that.
llvm-svn: 301056
clang-cl sets MicrosoftCompat. In that mode, we always give enums a fixed
underlying type, and for enums with fixed underlying type we never enter the
block that tries to emit ext_ms_forward_ref_enum. Fix this by requiring an
explicit underlying type when we're skipping this diagnostic.
We had a test for this warning, but it only ran in C++98 mode. clang-cl always
enables -std=c++14, so MicrosoftCompatibiliy-cxx98.cpp is a fairly useless
test. Fold it into MicrosoftCompatibility.cpp -- that way, the test checks if
-Wmicrosoft-enum-forward-reference can fire in clang-cl builds.
https://reviews.llvm.org/D32369
llvm-svn: 301032
The original idea was that if the attribute on an operator,
that the return-value unused-ness wouldn't matter. However,
all of the operators except postfix inc/dec return
references! References don't result in this warning
anyway, so those are already excluded.
Differential Revision: https://reviews.llvm.org/D32207
llvm-svn: 300764
Summary:
This patch implements [dcl.fct.def.coroutine]p8:
> The unqualified-id get_return_object_on_allocation_failure is looked up in the scope of
> class P by class member access lookup (3.4.5). If a declaration is found, ..., and if a
> global allocation function is selected, the ::operator new(size_t, nothrow_t) form shall be used.
> [...]
> The allocation function used in this case must have a non-throwing noexcept-specification.
Reviewers: GorNishanov, rsmith, majnemer, aaron.ballman
Reviewed By: GorNishanov
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D31562
llvm-svn: 300524
Eric Fiselier