Commit Graph

1369 Commits

Author SHA1 Message Date
Hans Wennborg 2d9d270e77 Revert 3e782bf809 "[Sema][MSVC] warn at dynamic_cast when /GR- is given"
This caused more warnings than expected, see https://crbug.com/1126019

Also reverts the follow-up 7907e5516.

> Differential Revision: https://reviews.llvm.org/D86369
2020-09-08 16:10:18 +02:00
Zequan Wu 3e782bf809 [Sema][MSVC] warn at dynamic_cast when /GR- is given
Differential Revision: https://reviews.llvm.org/D86369
2020-09-07 16:46:58 -07:00
Cullen Rhodes feed5a7239 [Sema][AArch64] Support arm_sve_vector_bits attribute
This patch implements the semantics for the 'arm_sve_vector_bits' type
attribute, defined by the Arm C Language Extensions (ACLE) for SVE [1].
The purpose of this attribute is to define vector-length-specific (VLS)
versions of existing vector-length-agnostic (VLA) types.

The semantics were already implemented by D83551, although the
implementation approach has since changed to represent VLSTs as
VectorType in the AST and fixed-length vectors in the IR everywhere
except in function args/returns. This is described in the prototype
patch D85128 demonstrating the new approach.

The semantic changes added in D83551 are changed since the
AttributedType is replaced by VectorType in the AST. Minimal changes
were necessary in the previous patch as the canonical type for both VLA
and VLS was the same (i.e. sizeless), except in constructs such as
globals and structs where sizeless types are unsupported. This patch
reverts the changes that permitted VLS types that were represented as
sizeless types in such circumstances, and adds support for implicit
casting between VLA <-> VLS types as described in section 3.7.3.2 of the
ACLE.

Since the SVE builtin types for bool and uint8 are both represented as
BuiltinType::UChar in VLSTs, two new vector kinds are implemented to
distinguish predicate and data vectors.

[1] https://developer.arm.com/documentation/100987/latest

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D85736
2020-08-27 10:38:32 +00:00
Richard Smith c1c1bed5d0 [c++14] Implement missed piece of N3323: use "converted constant" rules
for array bounds, not "integer constant" rules.

For an array bound of class type, this causes us to perform an implicit
conversion to size_t, instead of looking for a unique conversion to
integral or unscoped enumeration type. This affects which cases are
valid when a class has multiple implicit conversion functions to
different types.
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
Serge Pavlov 70e7aa4a4e [AST][FPEnv] Keep FP options in trailing storage of CallExpr
This change allow a CallExpr to have optional FPOptionsOverride object,
stored in trailing storage. The implementaion is made similar to the way
used in BinaryOperator.

Differential Revision: https://reviews.llvm.org/D84343
2020-07-24 12:04:19 +07:00
David Blaikie 36036aa70e Reapply "Rename/refactor isIntegerConstantExpression to getIntegerConstantExpression"
Reapply 49e5f603d4
which had been reverted in c94332919b.

Originally reverted because I hadn't updated it in quite a while when I
got around to committing it, so there were a bunch of missing changes to
new code since I'd written the patch.

Reviewers: aaron.ballman

Differential Revision: https://reviews.llvm.org/D76646
2020-07-21 20:57:12 -07:00
David Goldman dde98c82c0 Fix issue in typo handling which could lead clang to hang
Summary:
We need to detect when certain TypoExprs are not being transformed
due to invalid trees, otherwise we risk endlessly trying to fix it.

Reviewers: rsmith

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D84067
2020-07-20 11:42:11 -04:00
Benjamin Kramer 33c9d0320e Upgrade SmallSets of pointer-like types to SmallPtrSet
This is slightly more efficient. NFC.
2020-07-20 16:54:29 +02:00
Haojian Wu 17ef788df5 [AST][RecoveryExpr] Preserve the AST for invalid class constructions.
Differential Revision: https://reviews.llvm.org/D81090
2020-07-20 13:11:15 +02:00
David Blaikie c94332919b Revert "Rename/refactor isIntegerConstantExpression to getIntegerConstantExpression"
Broke buildbots since I hadn't updated this patch in a while. Sorry for
the noise.

This reverts commit 49e5f603d4.
2020-07-12 20:29:19 -07:00
David Blaikie 49e5f603d4 Rename/refactor isIntegerConstantExpression to getIntegerConstantExpression
There is a version that just tests (also called
isIntegerConstantExpression) & whereas this version is specifically used
when the value is of interest (a few call sites were actually refactored
to calling the test-only version) so let's make the API look more like
it.

Reviewers: aaron.ballman

Differential Revision: https://reviews.llvm.org/D76646
2020-07-12 19:43:24 -07:00
Richard Smith 065fc1eafe PR45521: Preserve the value kind when performing a standard conversion
sequence on a glvalue expression.

If the sequence is supposed to perform an lvalue-to-rvalue conversion,
then one will be specified as the first conversion in the sequence.
Otherwise, one should not be invented.
2020-07-07 18:28:28 -07:00
Haojian Wu 910689f0aa [AST] Move the "fallback to recovery expr" mechanism to CorrectDelayedTyposInExpr, NFC
Summary: Also delete two overloads, which don't seem necessary.

Reviewers: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82047
2020-06-18 08:20:05 +02:00
Richard Smith 56a872947a Remove improper uses of DiagnosticErrorTrap and hasErrorOccurred.
DiagnosticErrorTrap is usually inappropriate because it indicates
whether an error message was rendered in a given region (and is
therefore affected by -ferror-limit and by suppression of errors if we
see an invalid declaration).

hasErrorOccurred() is usually inappropriate because it indicates
whethere an "error:" message was displayed, regardless of whether the
message was a warning promoted to an error, and therefore depends on
things like -Werror that are usually irrelevant.

Where applicable, CodeSynthesisContexts are used to attach notes to
the first diagnostic produced in a region of code, isnstead of using an
error trap and then attaching a note to whichever diagnostic happened to
be produced last (or suppressing the note if the final diagnostic is a
disabled warning!).

This is mostly NFC.
2020-06-08 14:19:57 -07:00
Haojian Wu 28c2bdf18f [AST] Record SourceLocation for TypoExpr.
Reviewers: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D81008
2020-06-05 17:03:32 +02:00
Haojian Wu 21ccc684ff [AST][RecoveryExpr] Build RecoveryExpr for "undef_var" cases.
Summary:
For a none-function-like unresolved expression, clang builds a TypoExpr
for it, and tries to correct it afterwards. If the typo-correction
fails, clang just drops the whole expr.

This patch improves the recovery strategy -- if the typo-correction
fails, we preserve the AST by degrading the typo exprs to recovery
exprs.

This would improve toolings for "undef_var" broken cases:
```
void foo();
void test() {
  fo^o(undef_var); // go-to-def, hover still works.
}
```

TESTED=ran tests with this patch + turn-on-recovery-ast patch, it breaks
one declare_variant_messages testcase (the diagnostics are slightly
changed), I think it is acceptable.

```
Error: 'error' diagnostics seen but not expected:
  File llvm-project/clang/test/OpenMP/declare_variant_messages.cpp Line 16: expected 'match' clause on 'omp declare variant' directive
  File llvm-project/clang/test/OpenMP/declare_variant_messages.cpp Line 57: expected 'match' clause on 'omp declare variant' directive
error: 'warning' diagnostics expected but not seen:
  File llvm-project/clang/test/OpenMP/declare_variant_messages.cpp Line 47: the context selector 'kind' in the context set 'device' cannot have a score ('<invalid>'); score ignored
  File llvm-project/clang/test/OpenMP/declare_variant_messages.cpp Line 87: the context selector 'kind' in the context set 'device' cannot have a score ('<invalid>'); score ignored
error: 'warning' diagnostics seen but not expected:
  File llvm-project/clang/test/OpenMP/declare_variant_messages.cpp Line 47: the context selector 'kind' in the context set 'device' cannot have a score ('<recovery-expr>()'); score ignored
  File llvm-project/clang/test/OpenMP/declare_variant_messages.cpp Line 87: the context selector 'kind' in the context set 'device' cannot have a score ('<recovery-expr>()'); score ignored
6 errors generated.
```

Reviewers: sammccall, jdoerfert

Subscribers: sstefan1, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D80733
2020-06-02 15:58:56 +02:00
Richard Smith 00e5d38d40 Do not warn that an expression of the form (void)arr; is unused when
arr is a volatile non-local array.

This fixes a recent regression exposed by removing lvalue-to-rvalue
conversion of discarded volatile arrays. In passing, regularize the
rules we use to determine whether '(void)expr;' warns when expr is a
volatile glvalue.
2020-05-27 17:26:29 -07:00
Benjamin Kramer c0f210d636 Don't stash types that aren't copyable or moveable into a SmallVector
This seems to be working by accident.
2020-05-02 19:13:06 +02:00
Aaron Ballman 6a30894391 C++2a -> C++20 in some identifiers; NFC. 2020-04-21 15:37:19 -04:00
Benjamin Kramer 3ee1ec0b9d LangOptions cannot depend on ASTContext, make it not use ASTContext directly
Fixes a layering violation introduced in 2ba4e3a459.
2020-04-16 11:46:35 +02:00
Melanie Blower 2ba4e3a459 Move BinaryOperators.FPOptions to trailing storage
Reviewers: rjmccall

Differential Revision: https://reviews.llvm.org/D76384
2020-04-15 12:57:31 -07:00
Richard Smith bab6df86ae Rework how UuidAttr, CXXUuidofExpr, and GUID template arguments and constants are represented.
Summary:
Previously, we treated CXXUuidofExpr as quite a special case: it was the
only kind of expression that could be a canonical template argument, it
could be a constant lvalue base object, and so on. In addition, we
represented the UUID value as a string, whose source form we did not
preserve faithfully, and that we partially parsed in multiple different
places.

With this patch, we create an MSGuidDecl object to represent the
implicit object of type 'struct _GUID' created by a UuidAttr. Each
UuidAttr holds a pointer to its 'struct _GUID' and its original
(as-written) UUID string. A non-value-dependent CXXUuidofExpr behaves
like a DeclRefExpr denoting that MSGuidDecl object. We cache an APValue
representation of the GUID on the MSGuidDecl and use it from constant
evaluation where needed.

This allows removing a lot of the special-case logic to handle these
expressions. Unfortunately, many parts of Clang assume there are only
a couple of interesting kinds of ValueDecl, so the total amount of
special-case logic is not really reduced very much.

This fixes a few bugs and issues:
 * PR38490: we now support reading from GUID objects returned from
   __uuidof during constant evaluation.
 * Our Itanium mangling for a non-instantiation-dependent template
   argument involving __uuidof no longer depends on which CXXUuidofExpr
   template argument we happened to see first.
 * We now predeclare ::_GUID, and permit use of __uuidof without
   any header inclusion, better matching MSVC's behavior. We do not
   predefine ::__s_GUID, though; that seems like a step too far.
 * Our IR representation for GUID constants now uses the correct IR type
   wherever possible. We will still fall back to using the
      {i32, i16, i16, [8 x i8]}
   layout if a definition of struct _GUID is not available. This is not
   ideal: in principle the two layouts could have different padding.

Reviewers: rnk, jdoerfert

Subscribers: arphaman, cfe-commits, aeubanks

Tags: #clang

Differential Revision: https://reviews.llvm.org/D78171
2020-04-15 12:20:42 -07:00
zoecarver b25ec45809 Fix __is_pointer builtin type trait to work with Objective-C pointer types.
Summary: 5ade17e broke __is_pointer for Objective-C pointer types. This patch fixes the builtin and re-applies the change to type_traits.

Tags: #clang, #libc

Differential Revision: https://reviews.llvm.org/D77519
2020-04-08 10:02:53 -07:00
Akira Hatanaka d35a454170 [CodeGen] Emit destructor calls to destruct non-trivial C struct objects
returned by function calls or loaded from volatile objects

rdar://problem/51867864

Differential Revision: https://reviews.llvm.org/D66094
2020-03-20 18:34:22 -07:00
Richard Sandiford 4ece6f051b [Sema][SVE] Reject "delete" with sizeless types
Sizeless types can't be used with "new", so it doesn't make sense
to use them with "delete" either.  The SVE ACLE therefore doesn't
allow that.

This is slightly stronger than for normal incomplete types, since:

  struct S;
  void f(S *s) { delete s; }

is (by necessity) just a default-on warning rather than an error.

Differential Revision: https://reviews.llvm.org/D76219
2020-03-17 12:45:00 +00:00
Richard Sandiford 506406c4d5 [Sema][SVE] Reject "new" with sizeless types
new-expressions for a type T require sizeof(T) to be computable,
so the SVE ACLE does not allow them for sizeless types.  At the moment:

  auto f() { return new __SVInt8_t; }

creates a call to operator new with a zero size:

  %call = call noalias nonnull i8* @_Znwm(i64 0)

This patch reports an appropriate error instead.

Differential Revision: https://reviews.llvm.org/D76218
2020-03-17 12:23:46 +00:00
Richard Sandiford c47f971694 [Sema][SVE] Don't allow sizeless objects to be thrown
Summary:
The same rules for throwing and catching incomplete types also apply
to sizeless types.  This patch enforces that for throw statements.
It also make sure that we use "sizeless type" rather "incomplete type"
in the associated message.  (Both are correct, but "sizeless type" is
more specific and hopefully more user-friendly.)

The SVE ACLE simply extends the rule for incomplete types to
sizeless types.  However, throwing pointers to sizeless types
should not pose any real difficulty, so as an extension,
the clang implementation allows that.

Reviewers: sdesmalen, efriedma, rovka, rjmccall

Subscribers: tschuett, rkruppe, psnobl, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76088
2020-03-17 11:52:37 +00:00
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
Benjamin Kramer 66addf8e80 Revert "Fix regression in bdad0a1: force rebuilding of StmtExpr nodes in", "PR45083: Mark statement expressions as being dependent if they appear in"
This reverts commit f545ede91c.
This reverts commit bdad0a1b79.

This crashes clang. I'll follow up with reproduction instructions.
2020-03-05 14:14:31 +01:00
Simon Pilgrim 94885431e1 Fix some getAs/castAs null dereference static analyzer warnings.
Use castAs if we know the cast should succeed (or we're dereferencing without check), the castAs will assert as well so we can remove local non-null asserts.
2020-03-04 11:25:50 +00:00
Richard Smith bdad0a1b79 PR45083: Mark statement expressions as being dependent if they appear in
dependent contexts.

We previously assumed they were neither value- nor
instantiation-dependent under any circumstances, which would lead to
crashes and other misbehavior.
2020-03-03 15:20:40 -08:00
Richard Smith 98ed0c5475 PR44978: Accept as an extension some cases where destructor name lookup
is ambiguous, but only one of the possible lookup results could possibly
be right.

Clang recently started diagnosing ambiguity in more cases, and this
broke the build of Firefox. GCC, ICC, MSVC, and previous versions of
Clang all accept some forms of ambiguity here (albeit different ones in
each case); this patch mostly accepts anything any of those compilers
accept.
2020-02-26 14:55:31 -08:00
Roman Lebedev 3dd5a298bf
[clang] Annotating C++'s `operator new` with more attributes
Summary:
Right now we annotate C++'s `operator new` with `noalias` attribute,
which very much is healthy for optimizations.

However as per [[ http://eel.is/c++draft/basic.stc.dynamic.allocation | `[basic.stc.dynamic.allocation]` ]],
there are more promises on global `operator new`, namely:
* non-`std::nothrow_t` `operator new` *never* returns `nullptr`
* If `std::align_val_t align` parameter is taken, the pointer will also be `align`-aligned
* ~~global `operator new`-returned pointer is `__STDCPP_DEFAULT_NEW_ALIGNMENT__`-aligned ~~ It's more caveated than that.

Supplying this information may not cause immediate landslide effects
on any specific benchmarks, but it for sure will be healthy for optimizer
in the sense that the IR will better reflect the guarantees provided in the source code.

The caveat is `-fno-assume-sane-operator-new`, which currently prevents emitting `noalias`
attribute, and is automatically passed by Sanitizers ([[ https://bugs.llvm.org/show_bug.cgi?id=16386 | PR16386 ]]) - should it also cover these attributes?
The problem is that the flag is back-end-specific, as seen in `test/Modules/explicit-build-flags.cpp`.
But while it is okay to add `noalias` metadata in backend, we really should be adding at least
the alignment metadata to the AST, since that allows us to perform sema checks on it.

Reviewers: erichkeane, rjmccall, jdoerfert, eugenis, rsmith

Reviewed By: rsmith

Subscribers: xbolva00, jrtc27, atanasyan, nlopes, cfe-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D73380
2020-02-26 01:37:17 +03:00
Roman Lebedev b8fdafe68c
[Sema] Perform call checking when building CXXNewExpr
Summary:
There was even a TODO for this.
The main motivation is to make use of call-site based
`__attribute__((alloc_align(param_idx)))` validation (D72996).

Reviewers: rsmith, erichkeane, aaron.ballman, jdoerfert

Reviewed By: rsmith

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D73020
2020-02-26 01:36:44 +03:00
Anastasia Stulova fa755d3e71 [Sema][C++] Propagate conversion kind to specialize the diagnostics
Compute and propagate conversion kind to diagnostics helper in C++
to provide more specific diagnostics about incorrect implicit
conversions in assignments, initializations, params, etc...

Duplicated some diagnostics as errors because C++ is more strict.

Tags: #clang

Differential Revision: https://reviews.llvm.org/D74116
2020-02-25 16:05:37 +00:00
Richard Smith 76f888d0a5 Fix handling of destructor names that name typedefs.
1) Fix a regression in llvmorg-11-init-2485-g0e3a4877840 that would
reject some cases where a class name is shadowed by a typedef-name
causing a destructor declaration to be rejected. Prefer a tag type over
a typedef in destructor name lookup.

2) Convert the "type in destructor declaration is a typedef" error to an
error-by-default ExtWarn to allow codebases to turn it off. GCC and MSVC
do not enforce this rule.
2020-02-10 02:21:01 -08:00
Richard Smith 0e3a487784 PR12350: Handle remaining cases permitted by CWG DR 244.
Also add extension warnings for the cases that are disallowed by the
current rules for destructor name lookup, refactor and simplify the
lookup code, and improve the diagnostic quality when lookup fails.

The special case we previously supported for converting
p->N::S<int>::~S() from naming a class template into naming a
specialization thereof is subsumed by a more general rule here (which is
also consistent with Clang's historical behavior and that of other
compilers): if we can't find a suitable S in N, also look in N::S<int>.

The extension warnings are off by default, except for a warning when
lookup for p->N::S::~T() looks for T in scope instead of in N (or N::S).
That seems sufficiently heinous to warn on by default, especially since
we can't support it for a dependent nested-name-specifier.
2020-02-07 18:40:41 -08:00
Saar Raz 713562f548 [Concepts] Transform constraints of non-template functions to ConstantEvaluated
We would previously try to evaluate atomic constraints of non-template functions as-is,
and since they are now unevaluated at first, this would cause incorrect evaluation (bugs #44657, #44656).

Substitute into atomic constraints of non-template functions as we would atomic constraints
of template functions, in order to rebuild the expressions in a constant-evaluated context.
2020-01-25 23:00:24 +02:00
Richard Smith 13fa4e2e5a PR42108 Consistently diagnose binding a reference template parameter to
a temporary.

We previously failed to materialize a temporary when performing an
implicit conversion to a reference type, resulting in our thinking the
argument was a value rather than a reference in some cases.
2020-01-19 18:16:36 -08:00
Saar Raz a0f50d7316 [Concepts] Requires Expressions
Implement support for C++2a requires-expressions.

Re-commit after compilation failure on some platforms due to alignment issues with PointerIntPair.

Differential Revision: https://reviews.llvm.org/D50360
2020-01-19 00:23:26 +02:00
Saar Raz baa84d8cde Revert "[Concepts] Requires Expressions"
This reverts commit 0279318997.

There have been some failing tests on some platforms, reverting while investigating.
2020-01-18 14:58:01 +02:00
Saar Raz 0279318997 [Concepts] Requires Expressions
Implement support for C++2a requires-expressions.

Differential Revision: https://reviews.llvm.org/D50360
2020-01-18 09:15:36 +02:00
Richard Smith a42fd84cff Remove redundant CXXScopeSpec from TemplateIdAnnotation.
A TemplateIdAnnotation represents only a template-id, not a
nested-name-specifier plus a template-id. Don't make a redundant copy of
the CXXScopeSpec and store it on the template-id annotation.

This slightly improves error recovery by more properly handling the case
where we would form an invalid CXXScopeSpec while parsing a typename
specifier, instead of accidentally putting the token stream into a
broken "annot_template_id with a scope specifier, but with no preceding
annot_cxxscope token" state.
2020-01-17 15:47:21 -08:00
Amy Huang 44560762c6 Revert "Further implement CWG 2292"
This reverts commit ee0f1f1edc because it
causes an error on valid code.
See https://reviews.llvm.org/rGee0f1f1edc3ec0d4e698d50cc3180217448802b7.
2020-01-15 15:46:07 -08:00
Soumi Manna ee0f1f1edc Further implement CWG 2292
The core issue is that simple-template-id is ambiguous between class-name
and type-name. This fixes PR43966.
2020-01-15 08:49:44 -05:00
Erich Keane 349636d2bf Implement VectorType conditional operator GNU extension.
GCC supports the conditional operator on VectorTypes that acts as a
'select' in C++ mode. This patch implements the support. Types are
converted as closely to GCC's behavior as possible, though in a few
places consistency with our existing vector type support was preferred.

Note that this implementation is different from the OpenCL version in a
number of ways, so it unfortunately required a different implementation.

First, the SEMA rules and promotion rules are significantly different.

Secondly, GCC implements COND[i] != 0 ? LHS[i] : RHS[i] (where i is in
the range 0- VectorSize, for each element).  In OpenCL, the condition is
COND[i] < 0 ? LHS[i]: RHS[i].

In the process of implementing this, it was also required to make the
expression COND ? LHS : RHS type dependent if COND is type dependent,
since the type is now dependent on the condition.  For example:

    T ? 1 : 2;

Is not typically type dependent, since the result can be deduced from
the operands.  HOWEVER, if T is a VectorType now, it could change this
to a 'select' (basically a swizzle with a non-constant mask) with the 1
and 2 being promoted to vectors themselves.

While this is a change, it is NOT a standards incompatible change. Based
on my (and D. Gregor's, at the time of writing the code) reading of the
standard, the expression is supposed to be type dependent if ANY
sub-expression is type dependent.

Differential Revision: https://reviews.llvm.org/D71463
2020-01-13 13:27:20 -08:00
Richard Smith 9a6f4d451c Clean up and slightly generalize implementation of composite pointer
type computation, in preparation for P0388R4, which adds another few
cases here.

We now properly handle forming multi-level composite pointer types
involving nested Objective-C pointer types (as is consistent with
including them as part of the notion of 'similar types' on which this
rule is based). We no longer lose non-CVR qualifiers on nested pointer
types.
2020-01-10 16:12:00 -08:00
Richard Smith f041e9ad70 CWG2352: Allow qualification conversions during reference binding.
The language wording change forgot to update overload resolution to rank
implicit conversion sequences based on qualification conversions in
reference bindings. The anticipated resolution for that oversight is
implemented here -- we order candidates based on qualification
conversion, not only on top-level cv-qualifiers, including ranking
reference bindings against non-reference bindings if they differ in
non-top-level qualification conversions.

For OpenCL/C++, this allows reference binding between pointers with
differing (nested) address spaces. This makes the behavior of reference
binding consistent with that of implicit pointer conversions, as is the
purpose of this change, but that pre-existing behavior for pointer
conversions is itself probably not correct. In any case, it's now
consistently the same behavior and implemented in only one place.

This reinstates commit de21704ba9,
reverted in commit d8018233d1, with
workarounds for some overload resolution ordering problems introduced by
CWG2352.
2020-01-09 18:24:06 -08:00
David Blaikie d8018233d1 Revert "CWG2352: Allow qualification conversions during reference binding."
This reverts commit de21704ba9.

Regressed/causes this to error due to ambiguity:

  void f(const int * const &);
  void f(int *);
  int main() {
    int * x;
    f(x);
  }

(in case it's important - the original case where this turned up was a
member function overload in a class template with, essentially:

  f(const T1&)
  f(T2*)

(where T1 == X const *, T2 == X))

It's not super clear to me if this ^ is expected behavior, in which case
I'm sorry about the revert & happy to look into ways to fix the original
code.
2019-12-27 12:27:20 -08:00
Richard Smith de21704ba9 CWG2352: Allow qualification conversions during reference binding.
The language wording change forgot to update overload resolution to rank
implicit conversion sequences based on qualification conversions in
reference bindings. The anticipated resolution for that oversight is
implemented here -- we order candidates based on qualification
conversion, not only on top-level cv-qualifiers.

For OpenCL/C++, this allows reference binding between pointers with
differing (nested) address spaces. This makes the behavior of reference
binding consistent with that of implicit pointer conversions, as is the
purpose of this change, but that pre-existing behavior for pointer
conversions is itself probably not correct. In any case, it's now
consistently the same behavior and implemented in only one place.
2019-12-19 18:37:55 -08:00
Richard Smith 3ced23976a Refactor CompareReferenceRelationship and its callers in preparation for
implementing the resolution of CWG2352.

No functionality change, except that we now convert the referent of a
reference binding to the underlying type of the reference in more cases;
we used to happen to preserve the type sugar from the referent if the
only type change was in the cv-qualifiers.

This exposed a bug in how we generate code for trivial assignment
operators: if the type sugar (particularly the may_alias attribute)
got lost during reference binding, we'd use the "wrong" TBAA information
for the load during the assignment.
2019-12-18 14:05:57 -08:00
Richard Smith 4b00299958 [c++20] Add deprecation warnings for the expression forms deprecated by P1120R0.
This covers:
 * usual arithmetic conversions (comparisons, arithmetic, conditionals)
   between different enumeration types
 * usual arithmetic conversions between enums and floating-point types
 * comparisons between two operands of array type

The deprecation warnings are on-by-default (in C++20 compilations); it
seems likely that these forms will become ill-formed in C++23, so
warning on them now by default seems wise.

For the first two bullets, off-by-default warnings were also added for
all the cases where we didn't already have warnings (covering language
modes prior to C++20). These warnings are in subgroups of the existing
-Wenum-conversion (except that the first case is not warned on if either
enumeration type is anonymous, consistent with our existing
-Wenum-conversion warnings).
2019-12-16 17:49:45 -08:00
Sven van Haastregt 6236496561 [OpenCL] Fix address space for implicit conversion (PR43145)
Clang was creating a DerivedToBase ImplicitCastExpr that was also
casting between address spaces as part of the second step in the
standard conversion sequence.  Defer the address space conversion to
the third step in the sequence instead, such that we get a separate
ImplicitCastExpr for the address space conversion.

Differential Revision: https://reviews.llvm.org/D70605
2019-12-02 14:20:15 +00:00
Reid Kleckner 812bdb3c13 [MS] Don't reference deleted copy ctors from catchable types
When throwing objects with deleted copy constructors, the copy ctor
field of the catchable type should remain null and the mangle name
changes. This already worked in simple cases, but in cases involving
non-trivial subobjects, sometimes LookupCopyingConstructor could return
a non-null but deleted constructor decl. Skip those and don't reference
them.

Fixes PR43680
2019-10-30 15:06:26 -07:00
David Goldman 7a2b704bf0 [Sema][Typo Correction] Fix another infinite loop on ambiguity
See also: D67515

- For the given call expression we would end up repeatedly
   trying to transform the same expression over and over again

- Fix is to keep the old TransformCache when checking for ambiguity

Differential Revision: https://reviews.llvm.org/D69060
2019-10-25 13:20:27 -04:00
Richard Smith 70f59b5bbc When diagnosing an ambiguity, only note the candidates that contribute
to the ambiguity, rather than noting all viable candidates.
2019-10-24 14:58:29 -07:00
Peter Collingbourne 766f15814a Sema: Create a no-op implicit cast for lvalue function conversions.
This fixes an assertion failure in the case where an implicit conversion for a
function call involves an lvalue function conversion, and makes the AST for
initializations involving implicit lvalue function conversions more accurate.

Differential Revision: https://reviews.llvm.org/D66437

llvm-svn: 375313
2019-10-19 00:34:54 +00:00
Simon Pilgrim e14851259e SemaExprCXX - silence static analyzer getAs<> null dereference warnings. NFCI.
The static analyzer is warning about potential null dereferences, but in these cases we should be able to use castAs<> directly and if not assert will fire for us.

llvm-svn: 375101
2019-10-17 11:12:31 +00:00
Richard Smith 1e3a8d12a1 Suppress false-positive -Wdeprecated-volatile warning from __is_*_assignable(volatile T&, U).
llvm-svn: 374580
2019-10-11 17:59:09 +00:00
Richard Smith 4a6861a7e5 [c++20] P1152R4: warn on any simple-assignment to a volatile lvalue
whose value is not ignored.

We don't warn on all the cases that are deprecated: specifically, we
choose to not warn for now if there are parentheses around the
assignment but its value is not actually used. This seems like a more
defensible rule, particularly for cases like sizeof(v = a), where the
parens are part of the operand rather than the sizeof syntax.

llvm-svn: 374135
2019-10-09 02:04:54 +00:00
Richard Smith 772e266fbf Properly handle instantiation-dependent array bounds.
We previously failed to treat an array with an instantiation-dependent
but not value-dependent bound as being an instantiation-dependent type.
We now track the array bound expression as part of a constant array type
if it's an instantiation-dependent expression.

llvm-svn: 373685
2019-10-04 01:25:59 +00:00
Richard Smith 5d96b4ce28 Check for qualified function types after substituting into the operand
of 'typeid'.

This is a rare place where it's valid for a function type to be
substituted but not valid for a qualified function type to be
substituted, so needs a special check.

llvm-svn: 373648
2019-10-03 18:55:23 +00:00
Simon Pilgrim 1cd399c915 Silence static analyzer getAs<RecordType> null dereference warnings. NFCI.
The static analyzer is warning about potential null dereferences, but in these cases we should be able to use castAs<RecordType> directly and if not assert will fire for us.

llvm-svn: 373584
2019-10-03 11:22:48 +00:00
Zoe Carver 511dbd83d6 Fix __is_signed builtin
Summary: This patch fixes the __is_signed builtin type trait to work with floating point types and enums. Now, the builtin will return true if it is passed a floating point type and false for an enum type.

    Reviewers: EricWF, rsmith, erichkeane, craig.topper, efriedma

    Subscribers: cfe-commits

    Tags: #clang

    Differential Revision: https://reviews.llvm.org/D67897

llvm-svn: 372621
2019-09-23 15:41:20 +00:00
David Goldman 6d18650421 [Sema][Typo Correction] Fix potential infite loop on ambiguity checks
Summary:
This fixes a bug introduced in D62648, where Clang could infinite loop
if it became stuck on a single TypoCorrection when it was supposed to
be testing ambiguous corrections. Although not a common case, it could
happen if there are multiple possible corrections with the same edit
distance.

The fix is simply to wipe the TypoExpr from the `TransformCache` so that
the call to `TransformTypoExpr` doesn't use the `CachedEntry`.

Reviewers: rsmith

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67515

llvm-svn: 371859
2019-09-13 14:43:24 +00:00
David Goldman fd4d77707f [Sema][Typo] Fix assertion failure for expressions with multiple typos
Summary:
As Typo Resolution can create new TypoExprs while resolving typos,
it is necessary to recurse through the expression to search for more
typos.

This should fix the assertion failure in `clang::Sema::~Sema()`:
  `DelayedTypos.empty() && "Uncorrected typos!"`

Notes:
- In case some TypoExprs are created but thrown away, Sema
  now has a Vector that is used to keep track of newly created
  typos.
- For expressions with multiple typos, we only give suggestions
  if we are able to resolve all typos in the expression
- This patch is similar to D37521 except that it does not eagerly
  commit to a correction for the first typo in the expression.
  Instead, it will search for corrections which fix all of the
  typos in the expression.

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D62648

llvm-svn: 369427
2019-08-20 19:03:15 +00:00
Richard Smith 9e77f524b5 Fix handling of class member access into a vector type.
When handling a member access into a non-class, non-ObjC-object type, we
would perform a lookup into the surrounding scope as if for an
unqualified lookup. If the member access was followed by a '<' and this
lookup (or the typo-correction for it) found a template name, we'd treat
the member access as naming that template.

Now we treat such accesses as never naming a template if the type of the
object expression is of vector type, so that vector component accesses
are never misinterpreted as naming something else. This is not entirely
correct, since it is in fact valid to name a template from the enclosing
scope in this context, when invoking a pseudo-destructor for the vector
type via an alias template, but that's very much a corner case, and this
change leaves that case only as broken as the corresponding case for
Objective-C types is.

This incidentally adds support for dr2292, which permits a 'template'
keyword at the start of a member access naming a pseudo-destructor.

llvm-svn: 368940
2019-08-14 22:57:50 +00:00
Jan Korous e72321f38e [clang][NFCI] Fix random typos
llvm-svn: 366823
2019-07-23 16:54:11 +00:00
Anastasia Stulova 46b55fa58d [OpenCL] Update comments/diagnostics to refer to C++ for OpenCL
Clang doesn't implement OpenCL C++, change the comments to
reflect that.

Differential Revision: https://reviews.llvm.org/D64867

llvm-svn: 366421
2019-07-18 10:02:35 +00:00
Marco Antognini 9eb95903da [OpenCL][Sema] Minor refactoring and constraint checking
Summary:
Simplify code a bit and add assertion to address post-landing comments
from D64083.

Subscribers: yaxunl, Anastasia, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64804

llvm-svn: 366306
2019-07-17 08:52:09 +00:00
Rui Ueyama 49a3ad21d6 Fix parameter name comments using clang-tidy. NFC.
This patch applies clang-tidy's bugprone-argument-comment tool
to LLVM, clang and lld source trees. Here is how I created this
patch:

$ git clone https://github.com/llvm/llvm-project.git
$ cd llvm-project
$ mkdir build
$ cd build
$ cmake -GNinja -DCMAKE_BUILD_TYPE=Debug \
    -DLLVM_ENABLE_PROJECTS='clang;lld;clang-tools-extra' \
    -DCMAKE_EXPORT_COMPILE_COMMANDS=On -DLLVM_ENABLE_LLD=On \
    -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ../llvm
$ ninja
$ parallel clang-tidy -checks='-*,bugprone-argument-comment' \
    -config='{CheckOptions: [{key: StrictMode, value: 1}]}' -fix \
    ::: ../llvm/lib/**/*.{cpp,h} ../clang/lib/**/*.{cpp,h} ../lld/**/*.{cpp,h}

llvm-svn: 366177
2019-07-16 04:46:31 +00:00
Marco Antognini d36e130a86 [OpenCL][Sema] Improve address space support for blocks
Summary:
This patch ensures that the following code is compiled identically with
-cl-std=CL2.0 and -fblocks -cl-std=c++.

    kernel void test(void) {
      void (^const block_A)(void) = ^{
        return;
      };
    }

A new test is not added because cl20-device-side-enqueue.cl will cover
this once blocks are further improved for C++ for OpenCL.

The changes to Sema::PerformImplicitConversion are based on
the parts of Sema::CheckAssignmentConstraints on block pointer
conversions.

Reviewers: rjmccall, Anastasia

Subscribers: yaxunl, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64083

llvm-svn: 365500
2019-07-09 15:04:27 +00:00
Reid Kleckner 345708b681 Revert [Sema] Resolve placeholder types before type deduction to silence spurious `-Warc-repeated-use-of-weak` warnings
This reverts r365382 (git commit 8b1becf2e3)

Appears to regress this semi-reduced fragment of valid code from windows
SDK headers:

  #define InterlockedIncrement64 _InterlockedIncrement64
  extern "C" __int64 InterlockedIncrement64(__int64 volatile *Addend);
  #pragma intrinsic(_InterlockedIncrement64)
  unsigned __int64 InterlockedIncrement(unsigned __int64 volatile *Addend) {
    return (unsigned __int64)(InterlockedIncrement64)((volatile __int64 *)Addend);
  }

Found on a buildbot here, but no mail was sent due to it already being
red:
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/48067

llvm-svn: 365393
2019-07-08 21:59:07 +00:00
Akira Hatanaka 8b1becf2e3 [Sema] Resolve placeholder types before type deduction to silence
spurious `-Warc-repeated-use-of-weak` warnings

The spurious -Warc-repeated-use-of-weak warnings are issued when an
initializer expression uses a weak ObjC pointer.

My first attempt to silence the warnings (r350917) caused clang to
reject code that is legal in C++17. The patch is based on the feedback I
received from Richard when the patch was reverted.

http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20190422/268945.html
http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20190422/268943.html

Differential Revision: https://reviews.llvm.org/D62645

llvm-svn: 365382
2019-07-08 20:04:39 +00:00
Sven van Haastregt 1006a068c6 [OpenCL] Improve diagnostic for placement new
Without an explicit declaration for placement new, clang would reject
uses of placement new with "'default new' is not supported in OpenCL
C++".  This may mislead users into thinking that placement new is not
supported, see e.g. PR42060.

Clarify that placement new requires an explicit declaration.

Differential Revision: https://reviews.llvm.org/D63561

llvm-svn: 364423
2019-06-26 13:31:24 +00:00
Gauthier Harnisch ef629c7ef8 [clang] Don't segfault on incorrect using directive (PR41400)
Summary:
this is a bugfixe for [[ https://bugs.llvm.org/show_bug.cgi?id=41400 | PR41400 ]]

added nullptr check at the relevent place and test

Reviewers: rsmith, riccibruno

Reviewed By: rsmith

Subscribers: jkooker, jkorous, riccibruno, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D60523

llvm-svn: 363360
2019-06-14 08:25:52 +00:00
Richard Smith 715f7a1bd0 For DR712: store on a DeclRefExpr whether it constitutes an odr-use.
Begin restructuring to support the forms of non-odr-use reference
permitted by DR712.

llvm-svn: 363086
2019-06-11 17:50:32 +00:00
Richard Smith 84be998497 Factor out duplicated code building a MemberExpr and marking it
referenced.

This reinstates r362563, reverted in r362597.

llvm-svn: 362757
2019-06-06 23:24:18 +00:00
Richard Smith dcf17ded66 Convert MemberExpr creation and serialization to work the same way as
most / all other Expr subclasses.

This reinstates r362551, reverted in r362597, with a fix to a bug that
caused MemberExprs to sometimes have a null FoundDecl after a round-trip
through an AST file.

llvm-svn: 362756
2019-06-06 23:24:15 +00:00
Benjamin Kramer 9b2b8ad8b1 Revert "Factor out duplicated code building a MemberExpr and marking it" and "Convert MemberExpr creation and serialization to work the same way as"
This reverts commits r362551 and r362563. Crashes during modules selfhost.

llvm-svn: 362597
2019-06-05 11:46:57 +00:00
Richard Smith 8ca5455764 Factor out duplicated code building a MemberExpr and marking it
referenced.

llvm-svn: 362563
2019-06-05 00:21:47 +00:00
Richard Smith c32ef4bc0b Convert MemberExpr creation and serialization to work the same way as
most / all other Expr subclasses.

llvm-svn: 362551
2019-06-04 21:29:28 +00:00
Richard Smith 7dcd73340b Factor out repeated code to build a DeclRefExpr and mark it referenced.
llvm-svn: 362537
2019-06-04 18:30:46 +00:00
Richard Smith 7bf8f6fa8a PR42104: Support instantiations of lambdas that implicitly capture
packs.

Two changes:
 * Track odr-use via FunctionParmPackExprs to properly handle dependent
   odr-uses of packs in generic lambdas.
 * Do not instantiate implicit captures; instead, regenerate them by
   instantiating the body of the lambda. This is necessary to
   distinguish between cases where only one element of a pack is
   captured and cases where the entire pack is captured.

This reinstates r362358 (reverted in r362375) with a fix for an
uninitialized variable use in UpdateMarkingForLValueToRValue.

llvm-svn: 362531
2019-06-04 17:17:20 +00:00
Simon Pilgrim c716e5d6de Revert rL362358 : PR42104: Support instantiations of lambdas that implicitly capture packs.
Two changes:
 * Track odr-use via FunctionParmPackExprs to properly handle dependent
   odr-uses of packs in generic lambdas.
 * Do not instantiate implicit captures; instead, regenerate them by
   instantiating the body of the lambda. This is necessary to
   distinguish between cases where only one element of a pack is
   captured and cases where the entire pack is captured.
........
Fixes http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win buildbot failures

llvm-svn: 362375
2019-06-03 09:56:09 +00:00
Richard Smith ea0c66be55 PR42104: Support instantiations of lambdas that implicitly capture
packs.

Two changes:
 * Track odr-use via FunctionParmPackExprs to properly handle dependent
   odr-uses of packs in generic lambdas.
 * Do not instantiate implicit captures; instead, regenerate them by
   instantiating the body of the lambda. This is necessary to
   distinguish between cases where only one element of a pack is
   captured and cases where the entire pack is captured.

llvm-svn: 362358
2019-06-03 06:02:10 +00:00
Richard Smith b5a45bb77e Defer building 'this' captures until we have left the capturing region
and returned to the context in which 'this' should be captured.

This means we now always mark 'this' referenced from the context in
which it's actually referenced, rather than potentially from some
context nested within that.

llvm-svn: 362182
2019-05-31 01:17:04 +00:00
Erich Keane d02f4a1043 Add Attribute NoThrow as an Exception Specifier Type
In response to https://bugs.llvm.org/show_bug.cgi?id=33235, it became
clear that the current mechanism of hacking through checks for the
exception specification of a function gets confused really quickly when
there are alternate exception specifiers.

This patch introcues EST_NoThrow, which is the equivilent of
EST_noexcept when caused by EST_noThrow. The existing implementation is
left in place to cover functions with no FunctionProtoType.

Differential Revision: https://reviews.llvm.org/D62435

llvm-svn: 362119
2019-05-30 17:31:54 +00:00
Richard Smith 30116531b8 Defer creating fields for captures until we finish building the
capturing expression or statement.

No functionality change yet. The intent is that we will also delay
building the initialization expression until the enclosing context, so
that:
a) we build the initialization expression in the right context, and
b) we can elide captures that are not odr-used, as suggested by P0588R1.

This also consolidates some duplicated code building capture fields into
a single place.

llvm-svn: 361893
2019-05-28 23:09:46 +00:00
Richard Smith 94ef686f57 Move code to mark a variable as odr-used adjacement to all the related
code.

No functional change intended.

llvm-svn: 361890
2019-05-28 23:09:42 +00:00
Richard Smith 8458c9ef42 Factor out repeated code to build 'this' expressions and mark them
referenced.

llvm-svn: 361588
2019-05-24 01:35:07 +00:00
Erich Keane 000228183b Ensure builtins use the target default Calling Convention
r355317 changed builtins/allocation functions to use the default calling
convention in order to support platforms that use non-cdecl calling
conventions by default.

However the default calling convention is overridable on Windows 32 bit
implementations with some of the /G options. The intent is to permit the
user to set the calling convention of normal functions, however it
should NOT apply to builtins and C++ allocation functions.

This patch ensures that the builtin/allocation functions always use the
Target specific Calling Convention, ignoring the user overridden version
of said default.

llvm-svn: 361507
2019-05-23 16:05:21 +00:00
Marshall Clow ce78105558 Make more friendly with unions. Reviewed as https://reviews.llvm.org/D61858
llvm-svn: 360614
2019-05-13 19:29:23 +00:00
Erik Pilkington f8ccf05293 [Sema] Mark array element destructors referenced during initialization
This fixes a crash where we would neglect to mark a destructor referenced for an
__attribute__((no_destory)) array. The destructor is needed though, since if an
exception is thrown we need to cleanup the elements.

rdar://48462498

Differential revision: https://reviews.llvm.org/D61165

llvm-svn: 360446
2019-05-10 17:52:26 +00:00
Akira Hatanaka c39a243da6 Assume `__cxa_allocate_exception` returns an under-aligned memory on
Darwin if the version of libc++abi isn't new enough to include the fix
in r319123

This patch resurrects r264998, which was committed to work around a bug
in libc++abi that was causing _cxa_allocate_exception to return a memory
that wasn't double-word aligned.

http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20160328/154332.html

In addition, this patch makes clang issue a warning if the type of the
thrown object requires an alignment that is larger than the minimum
guaranteed by the target C++ runtime.

rdar://problem/49864414

Differential Revision: https://reviews.llvm.org/D61667

llvm-svn: 360404
2019-05-10 02:16:37 +00:00
Richard Smith 8900944109 Remember to decay arrays to pointers before checking whether the
left-hand side of an -> operator is a pointer to class type.

llvm-svn: 360387
2019-05-09 22:22:48 +00:00
Richard Smith b23c5e8c3d [c++20] Implement P0846R0: allow (ADL-only) calls to template-ids whose
template name is not visible to unqualified lookup.

In order to support this without a severe degradation in our ability to
diagnose typos in template names, this change significantly restructures
the way we handle template-id-shaped syntax for which lookup of the
template name finds nothing.

Instead of eagerly diagnosing an undeclared template name, we now form a
placeholder template-name representing a name that is known to not find
any templates. When the parser sees such a name, it attempts to
disambiguate whether we have a less-than comparison or a template-id.
Any diagnostics or typo-correction for the name are delayed until its
point of use.

The upshot should be a small improvement of our diagostic quality
overall: we now take more syntactic context into account when trying to
resolve an undeclared identifier on the left hand side of a '<'. In
fact, this works well enough that the backwards-compatible portion (for
an undeclared identifier rather than a lookup that finds functions but
no function templates) is enabled in all language modes.

llvm-svn: 360308
2019-05-09 03:31:27 +00:00
Richard Smith b9fb121a62 [c++20] Implement P1009R2: allow omitting the array bound in an array
new expression.

This was voted into C++20 as a defect report resolution, so we
retroactively apply it to all prior language modes (though it can never
actually be used before C++11 mode).

llvm-svn: 360006
2019-05-06 03:47:15 +00:00
David Blaikie 5e32805050 SemaOverload: Complete candidates before emitting the error, to ensure diagnostics emitted (or suppressed) during completion don't interfere with the overload notes
Because diagnostics and their notes are not connected at the API level,
if the error message for an overload is emitted, then the overload
candidates are completed - if a diagnostic is emitted during that work,
the notes related to overload candidates would be attached to the latter
diagnostic, not the original error. Sort of worse, if the latter
diagnostic was disabled, the notes are disabled.

Reviewers: rsmith

Differential Revision: https://reviews.llvm.org/D61357

llvm-svn: 359854
2019-05-03 00:44:50 +00:00