Commit Graph

1501 Commits

Author SHA1 Message Date
Richard Smith 04ba185633 PR37556: Don't diagnose conflicts between instantiated unqualified
friend declarations and declarations found in inline namespaces within
the target context.
2020-08-24 23:26:15 -07:00
Haojian Wu 09e7fe9859 [AST][RecoveryAST] Preserve the type by default for recovery expression.
Differential Revision: https://reviews.llvm.org/D82657
2020-08-24 14:28:28 +02:00
Richard Smith 6f33936719 Explain why the array bound is non-constant in VLA diagnostics.
In passing, also use a more precise diagnostic to explain why an
expression is not an ICE if it's not of integral type.
2020-08-19 15:45:51 -07:00
Richard Smith fb943696cb PR47025, PR47043: Diagnose unexpanded parameter packs in concept
declarations and requires-expressions.
2020-08-07 18:19:39 -07:00
Haojian Wu 67174765db [AST][RecoveryExpr] Fix the missing type when rebuilding RecoveryExpr in TreeTransform.
Differential Revision: https://reviews.llvm.org/D85423
2020-08-07 11:15:19 +02:00
Richard Smith ed5a18fc03 PR30738: Implement two-phase name lookup for fold-expressions. 2020-08-06 16:56:39 -07:00
Richard Smith a648834313 PR46729: Reject explicit and partial specializations with C linkage. 2020-07-29 17:44:32 -07:00
Richard Smith 1cbdf932b4 PR46231: Promote diagnostic for 'template<...>;' from ExtWarn to Error.
No other compiler accepts this as an extension, not even in permissive
mode. We're not doing anyone any favors by allowing this, and it's
unlikely to be at all common, even in Clang-only code, in the wild.
2020-07-29 12:35:18 -07:00
Alexey Bader 8d27be8dba [OpenCL] Add global_device and global_host address spaces
This patch introduces 2 new address spaces in OpenCL: global_device and global_host
which are a subset of a global address space, so the address space scheme will be
looking like:

```
generic->global->host
                          ->device
             ->private
             ->local
constant
```

Justification: USM allocations may be associated with both host and device memory. We
want to give users a way to tell the compiler the allocation type of a USM pointer for
optimization purposes. (Link to the Unified Shared Memory extension:
https://github.com/intel/llvm/blob/sycl/sycl/doc/extensions/USM/cl_intel_unified_shared_memory.asciidoc)

Before this patch USM pointer could be only in opencl_global
address space, hence a device backend can't tell if a particular pointer
points to host or device memory. On FPGAs at least we can generate more
efficient hardware code if the user tells us where the pointer can point -
being able to distinguish between these types of pointers at compile time
allows us to instantiate simpler load-store units to perform memory
transactions.

Patch by Dmitry Sidorov.

Reviewed By: Anastasia

Differential Revision: https://reviews.llvm.org/D82174
2020-07-29 17:24:53 +03:00
Richard Smith 9cf98d26e7 PR46637: Fix handling of placeholder types in trailing-return-types.
Only permit a placeholder type in a trailing-return-type if it would
also have been permitted in the decl-specifier sequence of a
corresponding declaration with no trailing-return-type. The standard
doesn't actually say this, but this is the only thing that makes sense.

Also fix handling of an 'auto' in a trailing-return-type in a parameter
of a generic lambda. We used to crash if we saw such a thing.
2020-07-28 15:54:10 -07:00
Richard Smith 740a164dec PR46377: Fix dependence calculation for function types and typedef
types.

We previously did not treat a function type as dependent if it had a
parameter pack with a non-dependent type -- such a function type depends
on the arity of the pack so is dependent even though none of the
parameter types is dependent. In order to properly handle this, we now
treat pack expansion types as always being dependent types (depending on
at least the pack arity), and always canonically being pack expansion
types, even in the unusual case when the pattern is not a dependent
type. This does mean that we can have canonical types that are pack
expansions that contain no unexpanded packs, which is unfortunate but
not inaccurate.

We also previously did not treat a typedef type as
instantiation-dependent if its canonical type was not
instantiation-dependent. That's wrong because instantiation-dependence
is a property of the type sugar, not of the type; an
instantiation-dependent type can have a non-instantiation-dependent
canonical type.
2020-07-28 13:23:13 -07:00
Richard Smith 23d6525cbd Don't form a 'context-independent expr' reference to a member during
name annotation.

Instead, defer forming the member access expression or DeclRefExpr until
we build the use of ClassifyName's result. Just build an
UnresolvedLookupExpr to track the LookupResult until we're ready to
consume it.

This also reverts commit 2f7269b677 (other
than its testcase). That change was an attempted workaround for the same
problem.
2020-07-27 19:38:22 -07:00
Haojian Wu 684e416ef1 [AST][RecoveryExpr] Preserve the AST for invalid conditions.
Adjust an existing diagnostic test, which is an improvement of secondary diagnostic.

Differential Revision: https://reviews.llvm.org/D81163
2020-07-20 14:58:36 +02:00
Richard Smith bfd643353e Fix merging of two arity-only pack deductions.
If we deduced the arity of a pack in two different ways, but didn't
deduce an element of the pack in either of those deductions, we'd merge
that element to produce a null template argument, which we'd incorrectly
interpret as the merge having failed.

Testcase based on one supplied by Hubert Tong.
2020-07-14 10:02:07 -07:00
Vitaly Buka c06417b24d Fix check-all with -DLLVM_USE_SANITIZER=Address 2020-07-10 01:47:51 -07:00
Richard Smith f721e0582b PR46648: Do not eagerly instantiate default arguments for a generic
lambda when instantiating a call operator specialization.

We previously incorrectly thought that such substitution was happening
in the context of substitution into a local scope, which is a context
where we should perform eager default argument instantiation.
2020-07-09 17:24:20 -07:00
Richard Smith a5569f0898 Push parameters into the local instantiation scope before instantiating
a default argument.

Default arguments can (after recent language changes) refer to
parameters of the same function. Make sure they're added to the local
instantiation scope before transforming a default argument so that we
can remap such references to them properly.
2020-07-09 17:24:20 -07:00
Richard Smith 4544c2d95a Recover more gracefully from stack exhaustion during template argument
deduction.

Template argument deduction can trigger substitution, both with
explicitly-specified template arguments and with deduced template
arguments in various ways. We previously had no check for stack
exhaustion along some of those codepaths, making it fairly easy to crash
clang with a template resulting in a substitution that referred back to
that same template. We should now produce a proper diagnostic for such
cases rather than crashing.
2020-07-08 13:08:38 -07:00
Haojian Wu d285f29317 [AST][RecoveryExpr] Avoid spurious 'missing typename' diagnostic when the NNS contains errors.
Differential Revision: https://reviews.llvm.org/D82631
2020-06-30 16:18:32 +02:00
Richard Smith a6308c0ad9 When performing a substitution into a dependent alias template, mark the
outer levels as retained rather than omitting their arguments.

This better reflects what's going on (we're performing a substitution
while still inside a template), and in theory is more correct, but I've
not found a testcase where it matters in practice (largely because we
don't allow alias templates to be declared inside a function).

Fixed AST dumping of SubstNonTypeTemplateParm[Pack]Expr to demonstrate
that we're properly substituting through dependent alias templates. (We
can't deduce properly through these yet, but we can at least produce the
right input to template argument deduction.)

No functionality change intended.
2020-06-23 14:43:04 -07:00
Richard Smith 2a3b86c157 Fix rejects-valid when referencing an implicit operator== from within a
templated class.

When a defaulted operator<=> results in the injection of a defaulted
operator==, that operator== can be named by unqualified name within the
same class, even if the class is templated. To make this work, perform
the transform from defaulted operator<=> to defaulted operator== in the
template definition context instead of the template instantiation
context.

This results in our substituting into a declaration from a context where
we don't have a full list of template arguments (or indeed any), for
which we are now more careful to not spuriously instantiate declarations
that are not dependent on the arguments we're substituting.
2020-06-22 20:19:20 -07:00
Richard Smith 9f9373f86d Distinguish between template parameter substitutions that are forming
specializations and those that are done as part of rewrites.

Do not create Subst* nodes in the latter. We previously had a hybrid of
these two behaviors where we would only create some Subst* nodes but not
others during deduction guide rewrites.

No functional change intended, but the resulting ASTs are more
principled.
2020-06-22 19:34:52 -07:00
Richard Smith 009c9b83ac Fix multilevel deduction where an outer pack is used in the type of an
inner non-type pack at a different index.

We previously considered the index of the outer pack (which would refer
to an unrelated template parameter) to be deduced by deducing the inner
pack, because we inspected the (largely meaningless) type of an expanded
non-type template parameter pack.
2020-06-22 16:47:51 -07:00
Richard Smith e135cf8a03 Add -ast-dump-decl-types flag to include types of value and type
declarations in AST dumps.

Includes a testcase for deduction guide transformation that makes use of
this new dumping feature.
2020-06-22 16:47:51 -07:00
Richard Smith c36b03e325 The type of a reference to a non-type template parameter pack should
not be a pack expansion type.

Using a pack expansion type for a pack declaration makes sense, but
general expressions should never have pack expansion types. If we have a
pack `T *...V`, then the type of `V` is the type `T *`, which contains
an unexpanded pack, and is a pointer type.

This allows us to better diagnose issues where a template is invalid due
to some non-dependent portion of a dependent type of a non-type template
parameter pack.
2020-06-18 17:52:13 -07:00
Richard Smith 55b6f68f4b Revert "Fix rejects-valid when referencing an implicit operator== from within a"
This change may have caused some self-host failures. Reverting while
investigating.

This reverts commit c7fbe2191b.
2020-06-17 16:05:26 -07:00
Richard Smith c7fbe2191b Fix rejects-valid when referencing an implicit operator== from within a
templated class.

When a defaulted operator<=> results in the injection of a defaulted
operator==, that operator== can be named by unqualified name within the
same class, even if the class is templated. To make this work, perform
the transform from defaulted operator<=> to defaulted operator== in the
template definition context instead of the template instantiation
context.

This results in our substituting into a declaration from a context where
we don't have a full list of template arguments (or indeed any), for
which we are now more careful to not spuriously instantiate declarations
that are not dependent on the arguments we're substituting.
2020-06-17 15:12:04 -07:00
Richard Smith 1b8125b041 Don't assert if we find a dependently-typed variable in the
redeclaration chain for an array.

A prior attempt to fix this in r280330 didn't handle the case where the
old variable is dependent and the new one is not.

It is notable and worrying that the test case in this example forms a
redeclaration chain for a non-dependent variable that includes a
declaration with a dependent type. We should probably fix that too.
2020-06-16 19:41:13 -07:00
Haojian Wu 58ea1059df [AST][RecoveryExpr] Build recovery expressions by default for C++.
Reland https://reviews.llvm.org/D76696
All known crashes have been fixed, another attemption.

We have rolled out this to all internal users for a while, didn't see
big issues, we consider it is stable enough.

Reviewed By: sammccall

Subscribers: rsmith, hubert.reinterpretcast, ebevhan, jkorous, arphaman, kadircet, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D78350
2020-06-12 15:21:38 +02:00
Bruno Ricci 40ea01f654
[clang] Convert a default argument expression to the parameter type...
...before checking that the default argument is valid with
CheckDefaultArgumentVisitor.

Currently the restrictions on a default argument are checked with the visitor
CheckDefaultArgumentVisitor in ActOnParamDefaultArgument before
performing the conversion to the parameter type in SetParamDefaultArgument.

This was fine before the previous patch but now some valid code post-CWG 2346
is rejected:

void test() {
  const int i2 = 0;
  extern void h2a(int x = i2);     // FIXME: ok, not odr-use
  extern void h2b(int x = i2 + 0); // ok, not odr-use
}

This is because the reference to i2 in h2a has not been marked yet with
NOUR_Constant. i2 is marked NOUR_Constant when the conversion to the parameter
type is done, which is done just after.

The solution is to do the conversion to the parameter type before checking
the restrictions on default arguments with CheckDefaultArgumentVisitor.
This has the side-benefit of improving some diagnostics.

Differential Revision: https://reviews.llvm.org/D81616

Reviewed By: rsmith
2020-06-11 13:18:45 +01:00
Richard Smith 6c29073efb PR45589: Properly decompose overloaded `&&` and `||` operators in
constraint expressions.

We create overloaded `&&` and `||` operators to hold the possible
unqualified lookup results (if any) when the operands are dependent. We
could avoid building these in some cases (we will never use the stored
lookup results, and it would be better to not store them or perform the
lookups), but in the general case we will probably still need to handle
overloaded operators even with that optimization.
2020-05-12 13:45:45 -07:00
Florian Hahn ffcaed32ef [Matrix] Check non-dependent elt type before creating DepSizedMatrix.
We should check non-dependent element types before creating a
DependentSizedMatrixType. Otherwise we do not generate an error message
for dependent-sized matrix types with invalid non-dependent element
types, if the template is never instantiated. See the make5 struct in
the tests.

It also moves the SEMA template tests to
clang/test/SemaTemplate/matrix-type.cpp and introduces a few more test
cases.
2020-05-12 16:46:37 +01:00
Richard Smith d6425e2c14 Properly implement 'enum class' parsing.
The 'class' or 'struct' keyword is only permitted as part of either an
enum definition or a standalone opaque-enum-declaration, not as part of
an elaborated type specifier. We previously failed to diagnose this, and
generally didn't properly implement the restrictions on elaborated type
specifiers for enumeration types.

In passing, also fixed incorrect parsing for enum-bases, which we
previously parsed as a type-name, but are actually a type-specifier-seq.
This matters for cases like 'enum E : int *p;', which is valid as a
Microsoft extension.

Plus some minor parse diagnostic improvements.

Bumped the recently-added ExtWarn for 'enum E : int x;' to be
DefaultError; this is not an intentional extension, so producing an
error by default seems appropriate, but the warning flag to disable it
may still be useful for code written against old Clang. The same
treatment is given here to the diagnostic for 'enum class E x;', which
we similarly have incorrectly accepted for many years. These diagnostics
continue to be suppressed under -fms-extensions and when compiling
Objective-C code. We will need to decide separately whether Objective-C
should follow the C++ rules or the (older) MSVC rules.
2020-05-10 13:21:04 -07:00
Aaron Puchert f43859a099 PR45000: Let Sema::SubstParmVarDecl handle default args of lambdas in initializers
Summary:
We extend the behavior for local functions and methods of local classes
to lambdas in variable initializers. The initializer is not a separate
scope, but we treat it as such.

We also remove the (faulty) instantiation of default arguments in
TreeTransform::TransformLambdaExpr, because it doesn't do proper
initialization, and if it did, we would do it twice (and thus also emit
eventual errors twice).

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D76038
2020-04-22 22:37:21 +02:00
Richard Smith c56975e299 Fix template instantiation of a non-dependent call to an inherited
constructor with default arguments.

We used to try to rebuild the call as a call to the faked-up inherited
constructor, which is only a placeholder and lacks (for example) default
arguments. Instead, build the call by reference to the original
constructor.

In passing, add a note to say where a call that recursively uses a
default argument from within itself occurs. This is usually pretty
obvious, but still at least somewhat useful, and would have saved
significant debugging time for this particular bug.
2020-04-06 19:20:30 -07:00
Richard Smith 499b2a8d63 PR45294: Fix handling of assumed template names looked up in the lexical
scope.

There are a few contexts in which we assume a name is a template name;
if such a context is one where we should perform an unqualified lookup,
and lookup finds nothing, we would form a dependent template name even
if the name is not dependent. This happens in particular for the lookup
of a pseudo-destructor.

In passing, rename ActOnDependentTemplateName to just ActOnTemplateName
given that we apply it for non-dependent template names too.
2020-03-27 21:07:06 -07:00
Richard Smith 88c7ffaf94 Form invalid template-id annotations when parsing a construct that is
required to be a template-id but names an undeclared identifier.
2020-03-27 20:27:42 -07:00
Richard Smith 0c42539df3 Improve error recovery from missing '>' in template argument list.
Produce the conventional "to match this '<'" note, so that the user
knows why we expected a '>', and properly handle '>>' in C++11 onwards.
2020-03-27 18:59:01 -07:00
Richard Smith b3f6e3d6d6 Improve recovery from invalid template-ids.
Instead of bailing out of parsing when we encounter an invalid
template-name or template arguments in a template-id, produce an
annotation token describing the invalid construct.

This avoids duplicate errors and generally allows us to recover better.
In principle we should be able to extend this to store some kinds of
invalid template-id in the AST for tooling use, but that isn't handled
as part of this change.
2020-03-27 17:11:04 -07:00
Haojian Wu 62dea6e9be Revert "[AST] Build recovery expressions by default for C++."
This reverts commit 0788acbccb.
This reverts commit c2d7a1f79cedfc9fcb518596aa839da4de0adb69:  Revert "[clangd] Add test for FindTarget+RecoveryExpr (which already works). NFC"

It causes a crash on invalid code:

class X {
  decltype(unresolved()) foo;
};
constexpr int s = sizeof(X);
2020-03-26 16:25:32 +01:00
Sam McCall 159a9f7e76 [AST] Print a<b<c>> without extra spaces in C++11 or later.
Summary: It's not 1998 anymore.

Reviewers: kadircet

Subscribers: jkorous, arphaman, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76801
2020-03-26 09:53:54 +01:00
Haojian Wu 0788acbccb [AST] Build recovery expressions by default for C++.
Update the existing tests.

Reviewers: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76696
2020-03-25 09:00:48 +01:00
Haojian Wu 733edf9750 [AST] Add RecoveryExpr to retain expressions on semantic errors
Normally clang avoids creating expressions when it encounters semantic
errors, even if the parser knows which expression to produce.

This works well for the compiler. However, this is not ideal for
source-level tools that have to deal with broken code, e.g. clangd is
not able to provide navigation features even for names that compiler
knows how to resolve.

The new RecoveryExpr aims to capture the minimal set of information
useful for the tools that need to deal with incorrect code:

source range of the expression being dropped,
subexpressions of the expression.
We aim to make constructing RecoveryExprs as simple as possible to
ensure writing code to avoid dropping expressions is easy.

Producing RecoveryExprs can result in new code paths being taken in the
frontend. In particular, clang can produce some new diagnostics now and
we aim to suppress bogus ones based on Expr::containsErrors.

We deliberately produce RecoveryExprs only in the parser for now to
minimize the code affected by this patch. Producing RecoveryExprs in
Sema potentially allows to preserve more information (e.g. type of an
expression), but also results in more code being affected. E.g.
SFINAE checks will have to take presence of RecoveryExprs into account.

Initial implementation only works in C++ mode, as it relies on compiler
postponing diagnostics on dependent expressions. C and ObjC often do not
do this, so they require more work to make sure we do not produce too
many bogus diagnostics on the new expressions.

See documentation of RecoveryExpr for more details.

original patch from Ilya
This change is based on https://reviews.llvm.org/D61722

Reviewers: sammccall, rsmith

Reviewed By: sammccall, rsmith

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69330
2020-03-24 09:20:37 +01:00
Richard Smith b20ab412bf Teach TreeTransform to substitute into resolved TemplateArguments.
This comes up when substituting into an already-substituted template
argument during constraint satisfaction checking.
2020-03-19 12:43:11 -07:00
Haojian Wu 0dd0b1017c [Parser] Avoid spurious 'missing template' error in presence of typos.
Suppress those diagnostics if lhs of a member expression contains
errors. Typo correction produces dependent expressions even in
non-template code, that led to spurious diagnostics before.

previous:
    /tmp/t.cpp:6:17: error: use 'template' keyword to treat 'f' as a dependent template name
    auto a = bilder.f<int>();
                    ^
                    template
    /tmp/t.cpp:6:10: error: use of undeclared identifier 'bilder'; did you mean 'builder'?
    auto a = bilder.f<int>();
             ^~~~~~
             builder

vs now:

    /tmp/t.cpp:6:10: error: use of undeclared identifier 'bilder'; did you mean 'builder'?
    auto a = bilder.f<int>();
             ^~~~~~
             builder

Original patch from Ilya.

Reviewers: sammccall

Reviewed By: sammccall

Tags: #clang

Differential Revision: https://reviews.llvm.org/D65592
2020-03-19 16:15:27 +01:00
Richard Smith c48442c9f3 PR45207: Fix crash if constrained-type-specifier annotation forms a
template_id annotation when parsing a type.
2020-03-17 13:18:23 -07:00
Saar Raz 19fccc52ff [Concepts] Fix incorrect control flow when TryAnnotateTypeConstraint annotates an invalid template-id
TryAnnotateTypeConstraint could annotate a template-id which doesn't end up being a type-constraint,
in which case control flow would incorrectly flow into ParseImplicitInt.

Reenter the loop in this case.
Enable relevant tests for C++20. This required disabling typo-correction during TryAnnotateTypeConstraint
and changing a test case which is broken due to a separate bug (will be reported and handled separately).
2020-03-17 01:49:42 +02:00
Richard Smith 5c845c1c50 PR45083: Mark statement expressions as being dependent if they appear in
a dependent context.

This matches the GCC behavior.

We track the enclosing template depth when determining whether a
statement expression is within a dependent context; there doesn't appear
to be any other reliable way to determine this.

We previously assumed they were neither value- nor
instantiation-dependent under any circumstances, which would lead to
crashes and other misbehavior.
2020-03-10 14:45:04 -07:00
Saar Raz 9769e1ee9a [Concepts] Fix incorrect DeclContext for transformed RequiresExprBodyDecl
We would assign the incorrect DeclContext when transforming the RequiresExprBodyDecl, causing incorrect
handling of 'this' inside RequiresExprBodyDecls (bug #45162).

Assign the current context as the DeclContext of the transformed decl.
2020-03-10 23:17:00 +02:00
Richard Smith 6333cc2a12 Revert "PR45083: Mark statement expressions as being dependent if they contain"
This reverts commit 2669e41b7b, which was
pushed by mistake.
2020-03-09 17:03:56 -07:00