Also add testcases for a bunch of expression forms that cause our evaluator to
crash. See PR33140 and PR32864 for crashes that this was causing.
This reverts r305287, which reverted r305239, which reverted r301742. The
previous revert claimed that buildbots were broken, but did not add any
testcases and the buildbots have lost all memory of what was wrong here.
Changes to test/OpenMP are not reverted; another change has triggered those
tests to change their output in the same way that r301742 did.
llvm-svn: 306346
definition or non-reference class type.
The crash occurs when there is a template parameter list in a class that
is missing the closing angle bracket followed by a definition of a
struct. For example:
class C0 {
public:
template<typename T, typename T1 = T // missing closing angle bracket
struct S0 {};
C0() : m(new S0<int>) {}
S0<int> *m;
};
This happens because the parsed struct is added to the scope of the
enclosing class without having its access specifier set, which results
in an assertion failure in SemaAccess.cpp later.
This commit fixes the crash by adding the parsed struct to the enclosing
file scope and marking structs as invalid if they are defined in
template parameter lists.
rdar://problem/31783961
rdar://problem/19570630
Differential Revision: https://reviews.llvm.org/D33606
llvm-svn: 306317
While a function body is being parsed, the function declaration is not considered
as a definition because it does not have a body yet. In some cases it leads to
incorrect interpretation, the case is presented in
https://bugs.llvm.org/show_bug.cgi?id=14785:
```
template<typename T> struct Somewhat {
void internal() const {}
friend void operator+(int const &, Somewhat<T> const &) {}
};
void operator+(int const &, Somewhat<char> const &x) { x.internal(); }
```
When statement `x.internal()` in the body of global `operator+` is parsed, the type
of `x` must be completed, so the instantiation of `Somewhat<char>` is started. It
instantiates the declaration of `operator+` defined inline, and makes a check for
redefinition. The check does not detect another definition because the declaration
of `operator+` is still not defining as does not have a body yet.
To solves this problem the function `isThisDeclarationADefinition` considers
a function declaration as a definition if it has flag `WillHaveBody` set.
This change fixes PR14785.
Differential Revision: https://reviews.llvm.org/D30375
This is a recommit of 305379, reverted in 305381, with small changes.
llvm-svn: 305903
As the bug report says,
struct A
{
template<typename T> operator T();
};
void foo()
{
A().operator auto();
}
causes: "undeduced type in IR-generation
UNREACHABLE executed at llvm/tools/clang/lib/CodeGen/CodeGenFunction.cpp:208!"
The problem is that in this case, "T" is being deduced as "auto",
which I believe is incorrect.
The 'operator auto' implementation in Clang is standards compliant, however
there is a defect report against core (1670).
Differential Revision: https://reviews.llvm.org/D34370
llvm-svn: 305812
While a function body is being parsed, the function declaration is not considered
as a definition because it does not have a body yet. In some cases it leads to
incorrect interpretation, the case is presented in
https://bugs.llvm.org/show_bug.cgi?id=14785:
```
template<typename T> struct Somewhat {
void internal() const {}
friend void operator+(int const &, Somewhat<T> const &) {}
};
void operator+(int const &, Somewhat<char> const &x) { x.internal(); }
```
When statement `x.internal()` in the body of global `operator+` is parsed, the type
of `x` must be completed, so the instantiation of `Somewhat<char>` is started. It
instantiates the declaration of `operator+` defined inline, and makes a check for
redefinition. The check does not detect another definition because the declaration
of `operator+` is still not defining as does not have a body yet.
To solves this problem the function `isThisDeclarationADefinition` considers
a function declaration as a definition if it has flag `WillHaveBody` set.
This change fixes PR14785.
Differential Revision: https://reviews.llvm.org/D30375
llvm-svn: 305379
Summary:
Currently we build the co_await expressions on the wrong implicit statements of the implicit ranged for; Specifically we build the co_await expression wrapping the range declaration, but it should wrap the begin expression.
This patch fixes co_await on range for.
Reviewers: rsmith, GorNishanov
Reviewed By: GorNishanov
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D34021
llvm-svn: 305363
Summary:
This way, the behavior of that warning flag
more closely resembles that of GCC.
Do note that there is at least one false-negative (see FIXME in tests).
Fixes PR4802.
Testing:
```
ninja check-clang-sema check-clang-semacxx
```
Reviewers: dblaikie, majnemer, rnk
Reviewed By: dblaikie, rnk
Subscribers: cfe-commits, alexfh, rnk
Differential Revision: https://reviews.llvm.org/D33102
llvm-svn: 305147
This is not required by the standard (yet), but there seems to be reasonable
support for this being a defect according to CWG discussion, and libstdc++ 7.1
relies on it working.
llvm-svn: 304946
RecursiveASTVisitor was not properly recursing through a
SubstTemplateTypeParmTypes, resulting in crashes in pack expansion where we
couldn't always find an unexpanded pack within a pack expansion.
We also have an issue where substitution of deduced template arguments for an
implicit deduction guide creates the "impossible" case of naming a
non-dependent member of the current instantiation, but within a specialization
that is actually instantiated from a different (partial/explicit)
specialization of the template. We resolve this by declaring that constructors
that do so can only be used to deduce specializations of the primary template.
I'm running this past CWG to see if people agree this is the right thing to do.
llvm-svn: 304862
Modifies FunctionDecl::isThisDeclarationADefinition so that it covers
all the cases checked by FunctionDecl::isDefined. Implements the latter
method by call to isThisDeclarationADefinition.
This change is a part of the patch D30170.
llvm-svn: 304684
Summary:
We were not handling correctly rebuilding of parameter and were not creating copies for them.
Now we will always rebuild parameter moves in TreeTransform's TransformCoroutineBodyStmt.
Reviewers: rsmith, GorNishanov
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D33797
llvm-svn: 304620
Summary:
This hooks up the detailed diagnostics of why constant initialization was
not possible if require_constant_initialization reports an error.
I have updated the test to account for the new notes.
Reviewed By: EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D24371
llvm-svn: 304451
Unlike the GCC-compatible __has_trivial_destructor trait, this one computes the
right answer rather than performing the quirky set of checks described in GCC's
documentation (https://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html).
MSVC also has a __has_trivial_destructor trait which is the same as its (and
now Clang's) __is_trivially_destructible trait; we might want to consider
changing the behavior of __has_trivial_destructor if we're targeting an MSVC
platform, but I'm not doing so for now.
While implementing this I found that we were incorrectly rejecting
__is_destructible queries on arrays of unknown bound of incomplete types; that
too is fixed, and I've added similar tests for other traits for good measure.
llvm-svn: 304376
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
Richard Smith