Commit Graph

912 Commits

Author SHA1 Message Date
Aaron Puchert 825f80e111 [Sema] Introduce function reference conversion, NFC
Technically 'noexcept' isn't a qualifier, so this should be a separate conversion.

Also make the test a pure frontend test.

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D67112
2020-11-22 20:51:57 +01:00
Richard Smith 2177e4555a PR47861: Expand dangling reference warning to look through copy
construction, and to assume that assignment operators return *this.
2020-10-30 10:19:50 -07:00
Richard Smith ba4768c966 [c++20] For P0732R2 / P1907R1: Basic frontend support for class types as
non-type template parameters.

Create a unique TemplateParamObjectDecl instance for each such value,
representing the globally unique template parameter object to which the
template parameter refers.

No IR generation support yet; that will follow in a separate patch.
2020-10-21 13:21:41 -07:00
Richard Smith 79cb179b14 PR47870: Properly mangle placeholders for deduced class template
specializations that have no deduced type.
2020-10-18 13:57:41 -07:00
Richard Smith fc031d29be Switch the default of VerifyIntegerConstantExpression from constant
folding to not constant folding.

Constant folding of ICEs is done as a GCC compatibility measure, but new
code was picking it up, presumably by accident, due to the bad default.

While here, also switch the flag from a bool to an enum to make it more
obvious what it means at call sites. This highlighted a couple of places
where our behavior is different between C++11 and C++14 due to switching
from checking for an ICE to checking for a converted constant
expression (where there is no 'fold' codepath).
2020-10-15 16:58:47 -07:00
Mark de Wever 0ce6d6b46e [Sema] List conversion validate character array.
The function `TryListConversion` didn't properly validate the following
part of the standard:

    Otherwise, if the parameter type is a character array [... ]
    and the initializer list has a single element that is an
    appropriately-typed string literal (8.5.2 [dcl.init.string]), the
    implicit conversion sequence is the identity conversion.

This caused the following call to `f()` to be ambiguous.
    void f(int(&&)[1]);
    void f(unsigned(&&)[1]);

    void g(unsigned i) {
      f({i});
    }

This issue only occurs when the initializer list had one element.

Differential Revision: https://reviews.llvm.org/D87561
2020-10-03 14:33:28 +02:00
Richard Smith 0f6facca97 Don't build a StringLiteral expression with reference type when
performing list-initialization of a char array reference from a braced
string literal of a smaller size.
2020-09-21 15:25:19 -07:00
Serge Pavlov f1cd6593da [AST][FPEnv] Keep FP options in trailing storage of CastExpr
This is recommit of 6c8041aa0f, reverted in de044f7562 because of some
fails. Original commit message is below.

This change allow a CastExpr to have optional FPOptionsOverride object,
stored in trailing storage. Of all cast nodes only ImplicitCastExpr,
CStyleCastExpr, CXXFunctionalCastExpr and CXXStaticCastExpr are allowed
to have FPOptions.

Differential Revision: https://reviews.llvm.org/D85960
2020-09-14 12:15:21 +07:00
Serge Pavlov de044f7562 Revert "[AST][FPEnv] Keep FP options in trailing storage of CastExpr"
This reverts commit 6c8041aa0f.
It caused some fails on buildbots.
2020-09-12 17:06:42 +07:00
Serge Pavlov 6c8041aa0f [AST][FPEnv] Keep FP options in trailing storage of CastExpr
This change allow a CastExpr to have optional FPOptionsOverride object,
stored in trailing storage. Of all cast nodes only ImplicitCastExpr,
CStyleCastExpr, CXXFunctionalCastExpr and CXXStaticCastExpr are allowed
to have FPOptions.

Differential Revision: https://reviews.llvm.org/D85960
2020-09-12 14:30:44 +07:00
Aleksandr Platonov 3fa0a039ab [clang] Check `expr` inside `InitListChecker::UpdateStructuredListElement()`
- Prevent nullptr-deference at try to emit warning for invalid `expr`
- Simplify `InitListChecker::UpdateStructuredListElement()` usages. We do not need to check `expr` and increment `StructuredIndex` (for invalid `expr`) before the call anymore.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D85193
2020-08-12 22:12:43 +03:00
Zequan Wu c354b2e3bf [Clang] Add note for bad conversion when expression is pointer to forward-declared type
Differential Revision: https://reviews.llvm.org/D85390
2020-08-07 11:06:08 -07:00
Haojian Wu 566b49884d [clang] Set the error-bit for ill-formed semantic InitListExpr.
When a semantic checking fails on a syntactic InitListExpr, we will
get an ill-formed semantic InitListExpr (e.g. some inits are nullptr),
using this semantic InitListExpr in clang (without setting the err-bits) is crashy.

Differential Revision: https://reviews.llvm.org/D84140
2020-07-21 09:39:44 +02:00
Aleksandr Platonov 1ba6fb9293
[clang] Fix a crash when passing a C structure of incompatible type to a function with a reference parameter.
__builtin_va_*() and __builtin_ms_va_*() are declared as functions with a
parameter of reference type.

This patch fixes a crash when using these functions in C where an argument
of structure type is incompatible with the parameter type.

Differential Revision: https://reviews.llvm.org/D82805

Reviewed By: riccibruno

Patch by: Aleksandr Platonov <platonov.aleksandr@huawei.com>
2020-07-08 16:57:54 +01:00
Leonard Chan 2f6bb2a692 [clang][Attribute] Fix noderef attribute false-negatives
`noderef` was failing to trigger warnings in some cases related to c++ style
casting. This patch addresses them.

Differential Revision: https://reviews.llvm.org/D77836
2020-06-10 12:20:54 -07:00
Haojian Wu 97b8dabba5 [AST] Fix a null initializer crash for InitListExpr
Summary:
The Initializer of a InitListExpr can be reset to null, which leads to
nullptr-acces crashes.

Reviewers: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D80980
2020-06-02 10:48:48 +02:00
Florian Hahn 8f3f88d2f5 [Matrix] Implement matrix index expressions ([][]).
This patch implements matrix index expressions
(matrix[RowIdx][ColumnIdx]).

It does so by introducing a new MatrixSubscriptExpr(Base, RowIdx, ColumnIdx).
MatrixSubscriptExprs are built in 2 steps in ActOnMatrixSubscriptExpr. First,
if the base of a subscript is of matrix type, we create a incomplete
MatrixSubscriptExpr(base, idx, nullptr). Second, if the base is an incomplete
MatrixSubscriptExpr, we create a complete
MatrixSubscriptExpr(base->getBase(), base->getRowIdx(), idx)

Similar to vector elements, it is not possible to take the address of
a MatrixSubscriptExpr.
For CodeGen, a new MatrixElt type is added to LValue, which is very
similar to VectorElt. The only difference is that we may need to cast
the type of the base from an array to a vector type when accessing it.

Reviewers: rjmccall, anemet, Bigcheese, rsmith, martong

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D76791
2020-06-01 20:08:49 +01:00
Richard Sandiford 69ab8b46b8 [Sema][SVE] Fix handling of initialisers for built-in SVE types
The built-in SVE types are supposed to be treated as opaque types.
This means that for initialisation purposes they should be treated
as a single unit, much like a scalar type.

However, as Eli pointed out, actually using "scalar" in the diagnostics
is likely to cause confusion, given the types are logically vectors.
The patch therefore uses custom diagnostics or generalises existing
ones.  Some of the messages use the word "indivisible" to try to make
it clear(er) that these types can't be initialised elementwise.

I don't think it's possible to trigger warn_braces_around_(scalar_)init
for sizeless types as things stand, since the types can't be used as
members or elements of more complex types.  But it seemed better to be
consistent with ext_many_braces_around_(scalar_)init, so the patch
changes it anyway.

Differential Revision: https://reviews.llvm.org/D76689
2020-05-06 12:24:27 +01:00
Aaron Ballman 1b3f1f4436 Rename warning identifiers from cxx2a to cxx20; NFC. 2020-04-22 14:31:13 -04:00
Aaron Ballman 6a30894391 C++2a -> C++20 in some identifiers; NFC. 2020-04-21 15:37:19 -04:00
Erik Pilkington 85cca945b4 [SemaObjC] Forbid storing an unboxed integer literal in an NSNumber
This fixes a common mistake (the 3 should be @3): NSNumber *n = 3. This extends
an existing check for NSString. Also, this only errs if the initializer isn't a
null pointer constant, so NSNumber *n = 0; continues to work. rdar://47029572

Differential revision: https://reviews.llvm.org/D78066
2020-04-20 15:22:51 -04:00
Tyker 180581cfcf [clang] Add support for consteval constructors
Summary:
Changes:
 - handle immediate invocations for constructors.
 - add tests

after this patch i believe the implementation of consteval is nearly standard compliant, but IR-gen still needs to be taught not to emit consteval declarations.

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: wchilders

Differential Revision: https://reviews.llvm.org/D74007
2020-03-20 11:33:54 +01:00
Reid Kleckner 86565c1309 Avoid SourceManager.h include in RawCommentList.h, add missing incs
SourceManager.h includes FileManager.h, which is expensive due to
dependencies on LLVM FS headers.

Remove dead BeforeThanCompare specialization.

Sink ASTContext::addComment to cpp file.

This reduces the time to compile a file that does nothing but include
ASTContext.h from ~3.4s to ~2.8s for me.

Saves these includes:
    219 -    ../clang/include/clang/Basic/SourceManager.h
    204 -    ../clang/include/clang/Basic/FileSystemOptions.h
    204 -    ../clang/include/clang/Basic/FileManager.h
    165 -    ../llvm/include/llvm/Support/VirtualFileSystem.h
    164 -    ../llvm/include/llvm/Support/SourceMgr.h
    164 -    ../llvm/include/llvm/Support/SMLoc.h
    161 -    ../llvm/include/llvm/Support/Path.h
    141 -    ../llvm/include/llvm/ADT/BitVector.h
    128 -    ../llvm/include/llvm/Support/MemoryBuffer.h
    124 -    ../llvm/include/llvm/Support/FileSystem.h
    124 -    ../llvm/include/llvm/Support/Chrono.h
    124 -    .../MSVCSTL/include/stack
    122 -    ../llvm/include/llvm-c/Types.h
    122 -    ../llvm/include/llvm/Support/NativeFormatting.h
    122 -    ../llvm/include/llvm/Support/FormatProviders.h
    122 -    ../llvm/include/llvm/Support/CBindingWrapping.h
    122 -    .../MSVCSTL/include/xtimec.h
    122 -    .../MSVCSTL/include/ratio
    122 -    .../MSVCSTL/include/chrono
    121 -    ../llvm/include/llvm/Support/FormatVariadicDetails.h
    118 -    ../llvm/include/llvm/Support/MD5.h
    109 -    .../MSVCSTL/include/deque
    105 -    ../llvm/include/llvm/Support/Host.h
    105 -    ../llvm/include/llvm/Support/Endian.h

Reviewed By: aaron.ballman, hans

Differential Revision: https://reviews.llvm.org/D75279
2020-02-27 13:49:40 -08:00
Richard Smith 9ce6dc9872 CWG1423: don't permit implicit conversion of nullptr_t to bool.
The C++ rules briefly allowed this, but the rule changed nearly 10 years
ago and we never updated our implementation to match. However, we've
warned on this by default for a long time, and no other compiler accepts
(even as an extension).
2020-02-11 06:52:45 -08:00
Richard Smith d28763cad0 Replace 'AllowExplicit' bool with an enum. No functionality change.
In passing, split it up into three values (no explicit functions /
explicit conversion functions only / any explicit functions) in
preparation for using that in a future change.
2020-01-30 17:16:50 -08:00
Richard Smith 1b5404aff3 PR44540: Prefer an inherited default constructor over an initializer
list constructor when initializing from {}.

We would previously pick between calling an initializer list constructor
and calling a default constructor unstably in this situation, depending
on whether the inherited default constructor had already been used
elsewhere in the program.
2020-01-14 19:29:50 -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
Richard Smith 2519554134 When diagnosing the lack of a viable conversion function, also list
explicit functions that are not candidates.

It's not always obvious that the reason a conversion was not possible is
because the function you wanted to call is 'explicit', so explicitly say
if that's the case.

It would be nice to rank the explicit candidates higher in the
diagnostic if an implicit conversion sequence exists for their
arguments, but unfortunately we can't determine that without potentially
triggering non-immediate-context errors that we're not permitted to
produce.
2020-01-09 15:15:02 -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
Michael Liao f2ace9d600 Add `QualType::hasAddressSpace`. NFC.
- Add that as a shorthand of <T>.getQualifiers().hasAddressSpace().
- Simplify related code.
2019-12-06 13:08:55 -05:00
Gabor Horvath bcd0798c47 [LifetimeAnalysis] Fix PR44150
References need somewhat special treatment. While copying a gsl::Pointer
will propagate the points-to set, creating an object from a reference
often behaves more like a dereference operation.

Differential Revision: https://reviews.llvm.org/D70755
2019-11-27 09:15:14 -08:00
Tyker b0561b3346 [NFC] Refactor representation of materialized temporaries
Summary:
this patch refactor representation of materialized temporaries to prevent an issue raised by rsmith in https://reviews.llvm.org/D63640#inline-612718

Reviewers: rsmith, martong, shafik

Reviewed By: rsmith

Subscribers: thakis, sammccall, ilya-biryukov, rnkovacs, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69360
2019-11-19 18:20:45 +01:00
Nico Weber c9276fbfdf Revert "[NFC] Refactor representation of materialized temporaries"
This reverts commit 08ea1ee2db.
It broke ./ClangdTests/FindExplicitReferencesTest.All
on the bots, see comments on https://reviews.llvm.org/D69360
2019-11-17 02:09:25 -05:00
Tyker 08ea1ee2db [NFC] Refactor representation of materialized temporaries
Summary:
this patch refactor representation of materialized temporaries to prevent an issue raised by rsmith in https://reviews.llvm.org/D63640#inline-612718

Reviewers: rsmith, martong, shafik

Reviewed By: rsmith

Subscribers: rnkovacs, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69360
2019-11-16 17:56:09 +01:00
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
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
Simon Pilgrim 920ff02ece SemaInit - 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: 373474
2019-10-02 14:02:18 +00:00
Richard Trieu e388725316 Revert r368237 - Update fix-it hints for std::move warnings.
r368237 attempted to improve fix-its for move warnings, but introduced some
regressions to -Wpessimizing-move.  Revert that change and add the missing
test cases to the pessimizing move test to prevent future regressions.

llvm-svn: 373421
2019-10-02 02:32:15 +00:00
Matthias Gehre f64f488670 Reland [LifetimeAnalysis] Support more STL idioms (template forward declaration and DependentNameType)
Reland after https://reviews.llvm.org/D66806 fixed the false-positive diagnostics.

Summary:
This fixes inference of gsl::Pointer on std::set::iterator with libstdc++ (the typedef for iterator
on the template is a DependentNameType - we can only put the gsl::Pointer attribute
on the underlaying record after instantiation)

inference of gsl::Pointer on std::vector::iterator with libc++ (the class was forward-declared,
we added the gsl::Pointer on the canonical decl (the forward decl), and later when the
template was instantiated, there was no attribute on the definition so it was not instantiated).

and a duplicate gsl::Pointer on some class with libstdc++ (we first added an attribute to
a incomplete instantiation, and then another was copied from the template definition
when the instantiation was completed).

We now add the attributes to all redeclarations to fix thos issues and make their usage easier.

Reviewers: gribozavr

Subscribers: Szelethus, xazax.hun, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66179

llvm-svn: 371182
2019-09-06 08:56:30 +00:00
Gabor Horvath 6f98400189 [LifetimeAnalysis] Fix some false positives
Differential Revision: https://reviews.llvm.org/D66806

llvm-svn: 370773
2019-09-03 16:17:24 +00:00
Simon Pilgrim b65370cf05 Fix variable HasArrayDesignator set but not used warning. NFCI.
llvm-svn: 370609
2019-09-01 13:10:08 +00:00
Richard Smith ff9bf925e7 [c++20] Add support for designated direct-list-initialization syntax.
This completes the implementation of P0329R4.

llvm-svn: 370558
2019-08-31 01:00:37 +00:00
Richard Smith 5030928d60 [c++20] Implement semantic restrictions for C++20 designated
initializers.

This has some interesting interactions with our existing extensions to
support C99 designated initializers as an extension in C++. Those are
resolved as follows:

 * We continue to permit the full breadth of C99 designated initializers
   in C++, with the exception that we disallow a partial overwrite of an
   initializer with a non-trivially-destructible type. (Full overwrite
   is OK, because we won't run the first initializer at all.)

 * The C99 extensions are disallowed in SFINAE contexts and during
   overload resolution, where they could change the meaning of valid
   programs.

 * C++20 disallows reordering of initializers. We only check for that for
   the simple cases that the C++20 rules permit (designators of the form
   '.field_name =' and continue to allow reordering in other cases).
   It would be nice to improve this behavior in future.

 * All C99 designated initializer extensions produce a warning by
   default in C++20 mode. People are going to learn the C++ rules based
   on what Clang diagnoses, so it's important we diagnose these properly
   by default.

 * In C++ <= 17, we apply the C++20 rules rather than the C99 rules, and
   so still diagnose C99 extensions as described above. We continue to
   accept designated C++20-compatible initializers in C++ <= 17 silently
   by default (but naturally still reject under -pedantic-errors).

This is not a complete implementation of P0329R4. In particular, that
paper introduces new non-C99-compatible syntax { .field { init } }, and
we do not support that yet.

This is based on a previous patch by Don Hinton, though I've made
substantial changes when addressing the above interactions.

Differential Revision: https://reviews.llvm.org/D59754

llvm-svn: 370544
2019-08-30 22:52:55 +00:00
Richard Smith cd839ccf99 Fix silent wrong-code bugs and crashes with designated initialization.
We failed to correctly handle the 'holes' left behind by designated
initializers in VerifyOnly mode. This would result in us thinking that a
designated initialization would be valid, only to find that it is not
actually valid when we come to build it. In a +Asserts build, that would
assert, and in a -Asserts build, that would silently lose some part of
the initialization or crash.

With this change, when an InitListExpr contains any designators, we now
always build a structured list so that we can track the locations of the
'holes' that we need to go back and fill in.

We could in principle do better: we only need the structured form if
there is a designator that jumps backwards (and can otherwise check for
the holes as we progress through the initializer list), but dealing with
that turns out to be rather complicated, so it's not done as part of
this patch.

llvm-svn: 370419
2019-08-29 22:49:34 +00:00
Richard Smith 33e9be6c8b Refactor InitListChecker to check only a single (explicit) initializer
list, rather than recursively checking multiple lists in C.

This simplification is in preparation for making InitListChecker
maintain more state that's specific to the explicit initializer list,
particularly when handling designated initialization.

llvm-svn: 370418
2019-08-29 22:49:33 +00:00
Richard Smith 8823dbc552 Refactor InitListChecker to make it a bit clearer that hasError is only
set to true in VerifyOnly mode in cases where it's also set to true when
actually building the initializer list.

Add FIXMEs for the two cases where that's not true. No functionality
change intended.

llvm-svn: 370417
2019-08-29 22:49:32 +00:00
Richard Smith 26a92d5852 Improve behavior in the case of stack exhaustion.
Summary:
Clang performs various recursive operations (such as template instantiation),
and may use non-trivial amounts of stack space in each recursive step (for
instance, due to recursive AST walks). While we try to keep the stack space
used by such steps to a minimum and we have explicit limits on the number of
such steps we perform, it's impractical to guarantee that we won't blow out the
stack on deeply recursive template instantiations on complex ASTs, even with
only a moderately high instantiation depth limit.

The user experience in these cases is generally terrible: we crash with
no hint of what went wrong. Under this patch, we attempt to do better:

 * Detect when the stack is nearly exhausted, and produce a warning with a
   nice template instantiation backtrace, telling the user that we might
   run slowly or crash.

 * For cases where we're forced to trigger recursive template
   instantiation in arbitrarily-deeply-nested contexts, check whether
   we're nearly out of stack space and allocate a new stack (by spawning
   a new thread) after producing the warning.

Reviewers: rnk, aaron.ballman

Subscribers: mgorny, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66361

llvm-svn: 369940
2019-08-26 18:18:07 +00:00