Commit Graph

473 Commits

Author SHA1 Message Date
Akira Hatanaka f466f0beda Disallow trivial_abi on a class if all copy and move constructors are
deleted

Instead of forcing the class to be passed in registers, which was what
r350920 did, issue a warning and inform the user that the attribute
cannot be used.

For more background, see this discussion:
http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20190128/259907.html

This fixes PR39683.

rdar://problem/47308221

Differential Revision: https://reviews.llvm.org/D57626
2020-06-10 14:12:13 -07:00
Richard Smith 825e3bb580 PR46209: properly determine whether a copy assignment operator is
trivial.

We previously took a shortcut by assuming that if a subobject had a
trivial copy assignment operator (with a few side-conditions), we would
always invoke it, and could avoid going through overload resolution.
That turns out to not be correct in the presenve of ref-qualifiers (and
also won't be the case for copy-assignments with requires-clauses
either). Use the same logic for lazy declaration of copy-assignments
that we use for all other special member functions.

Previously committed as c57f8a3a20. This
now also includes an extension of LLDB's workaround for handling special
members without the help of Sema to cover copy assignments.
2020-06-05 16:05:32 -07:00
Jonas Devlieghere df53f09056 Revert "PR46209: properly determine whether a copy assignment operator is"
This reverts commit c57f8a3a20.
2020-06-04 23:45:36 -07:00
Richard Smith c57f8a3a20 PR46209: properly determine whether a copy assignment operator is
trivial.

We previously took a shortcut by assuming that if a subobject had a
trivial copy assignment operator (with a few side-conditions), we would
always invoke it, and could avoid going through overload resolution.
That turns out to not be correct in the presenve of ref-qualifiers (and
also won't be the case for copy-assignments with requires-clauses
either). Use the same logic for lazy declaration of copy-assignments
that we use for all other special member functions.
2020-06-04 19:19:01 -07:00
Haojian Wu 89d9912cbf [AST] dont invaliate VarDecl when the initializer contains errors.
Summary:
This patch contains 2 separate changes:
1) the initializer of a variable should play no part in decl "invalid" bit;
2) preserve the invalid initializer via recovery exprs;

With 1), we will regress the diagnostics (one big regression is that we loose
the "selected 'begin' function with iterator type" diagnostic in for-range stmt;
but with 2) together, we don't have regressions (the new diagnostics seems to be
improved).

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D78116
2020-04-21 10:53:35 +02:00
Haojian Wu 9657385960 [AST] Dont invalide VarDecl even the default initializaiton is failed.
Summary:
This patch would cause clang emit more diagnostics, but it is much better than https://reviews.llvm.org/D76831

```cpp
struct A {
  A(int);
  ~A() = delete;
};
void k() {
  A a;
}

```

before the patch:

/tmp/t3.cpp:24:5: error: no matching constructor for initialization of 'A'
  A a;
    ^
/tmp/t3.cpp:20:3: note: candidate constructor not viable: requires 1 argument, but 0 were provided
  A(int);
  ^
/tmp/t3.cpp:19:8: note: candidate constructor (the implicit copy constructor) not viable: requires 1 argument, but 0 were provided
struct A {

After the patch:

/tmp/t3.cpp:24:5: error: no matching constructor for initialization of 'A'
  A a;
    ^
/tmp/t3.cpp:20:3: note: candidate constructor not viable: requires 1 argument, but 0 were provided
  A(int);
  ^
/tmp/t3.cpp:19:8: note: candidate constructor (the implicit copy constructor) not viable: requires 1 argument, but 0 were provided
struct A {
       ^
/tmp/t3.cpp:24:5: error: attempt to use a deleted function
  A a;
    ^
/tmp/t3.cpp:21:3: note: '~A' has been explicitly marked deleted here
  ~A() = delete;

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D77395
2020-04-14 12:58:48 +02:00
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
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
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 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 fbf915f01d Add a FIXME and corresponding test coverage for some suspicious behavior
forming composite ObjC pointer types in comparisons.
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
James Y Knight ccc4d83cda [ObjC] Diagnose implicit type coercion from ObjC 'Class' to object
pointer types.

For example, in Objective-C mode, the initialization of 'x' in:
```
  @implementation MyType
  + (void)someClassMethod {
    MyType *x = self;
  }
  @end
```
is correctly diagnosed with an incompatible-pointer-types warning, but
in Objective-C++ mode, it is not diagnosed at all -- even though
incompatible pointer conversions generally become an error in C++.

This patch fixes that oversight, allowing implicit conversions
involving Class only to/from unqualified-id, and between qualified and
unqualified Class, where the protocols are compatible.

Note that this does change some behaviors in Objective-C, as well, as
shown by the modified tests.

Of particular note is that assignment from from 'Class<MyProtocol>' to
'id<MyProtocol>' now warns. (Despite appearances, those are not
compatible types. 'Class<MyProtocol>' is not expected to have instance
methods defined by 'MyProtocol', while 'id<MyProtocol>' is.)

Differential Revision: https://reviews.llvm.org/D67983

llvm-svn: 375125
2019-10-17 15:27:04 +00:00
James Y Knight 1c982af059 [ObjC] Add some additional test cases around pointer conversions.
This is especially important for Objective-C++, which is entirely
missing this testing at the moment.

This annotates with "FIXME" the cases which I change in the next
patch -- I primarily wanted to document the current state of things so
that the effect of the code change is made clear.

Differential Revision: https://reviews.llvm.org/D67982

llvm-svn: 375124
2019-10-17 15:18:59 +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 8cb63232d9 If capturing a variable fails, add a capture anyway (and mark it
invalid) so that we can avoid repeated diagnostics for the same capture.

llvm-svn: 361891
2019-05-28 23:09:44 +00:00
Leonard Chan c72aaf62d3 Recommit r359859 "[Attribute/Diagnostics] Print macro if definition is an attribute declaration"
Updated with fix for read of uninitialized memory.

llvm-svn: 360109
2019-05-07 03:20:17 +00:00
Leonard Chan ef2dc25a96 Revert "[Attribute/Diagnostics] Print macro if definition is an attribute declaration"
This reverts commit fc40cbd9d8.

llvm-svn: 359859
2019-05-03 03:28:06 +00:00
Leonard Chan fc40cbd9d8 [Attribute/Diagnostics] Print macro if definition is an attribute declaration
If an address_space attribute is defined in a macro, print the macro instead
when diagnosing a warning or error for incompatible pointers with different
address_spaces.

We allow this for all attributes (not just address_space), and for multiple
attributes declared in the same macro.

Differential Revision: https://reviews.llvm.org/D51329

llvm-svn: 359826
2019-05-02 20:38:14 +00:00
Akira Hatanaka ac57af3284 [Sema][ObjC] Don't warn about an implicitly retained self if the
retaining block and all of the enclosing blocks are non-escaping.

If the block implicitly retaining self doesn't escape, there is no risk
of creating retain cycles, so clang shouldn't diagnose it and force
users to add self-> to silence the diagnostic.

Also, fix a bug where clang was failing to diagnose an implicitly
retained self inside a c++ lambda nested inside a block.

rdar://problem/25059955

Differential Revision: https://reviews.llvm.org/D60736

llvm-svn: 358624
2019-04-17 23:14:44 +00:00
JF Bastien cefafc4999 Thread Safety: also look at ObjC methods
Summary:
SExprBuilder::translateDeclRefExpr was only looking at FunctionDecl and not also looking at ObjCMethodDecl. It should consider both because the attributes can be used on Objective-C as well.

<rdar://problem/48941331>

Reviewers: dexonsmith, erik.pilkington

Subscribers: jkorous, jdoerfert, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D59523

llvm-svn: 356940
2019-03-25 20:06:32 +00:00
Erik Pilkington 13ee62f7d7 [Sema] Deduplicate some availability checking logic
Before this commit, we emit unavailable errors for calls to functions during
overload resolution, and for references to all other declarations in
DiagnoseUseOfDecl. The early checks during overload resolution aren't as good as
the DiagnoseAvailabilityOfDecl based checks, as they error on the code from
PR40991. This commit fixes this by removing the early checking.

llvm.org/PR40991
rdar://48564179

Differential revision: https://reviews.llvm.org/D59394

llvm-svn: 356599
2019-03-20 19:26:33 +00:00
Akira Hatanaka 1488ee4bd5 [ObjC] Emit a boxed expression as a compile-time constant if the
expression inside the parentheses is a valid UTF-8 string literal.

Previously clang emitted an expression like @("abc") as a message send
to stringWithUTF8String. This commit makes clang emit the boxed
expression as a compile-time constant instead.

This commit also has the effect of silencing the nullable-to-nonnull
conversion warning clang started emitting after r317727, which
originally motivated this commit (see https://oleb.net/2018/@keypath).

rdar://problem/42684601

Differential Revision: https://reviews.llvm.org/D58729

llvm-svn: 355662
2019-03-08 04:45:37 +00:00
Aaron Ballman 7eb66ba14a expected-no-diagnostics@ does not make sense, switching to a more idiomatic form; NFC.
llvm-svn: 355601
2019-03-07 15:03:06 +00:00
Akira Hatanaka a50489754a [Sema][ObjC] Allow declaring ObjC pointer members with non-trivial
ownership qualifications in C++ unions under ARC.

An ObjC pointer member with non-trivial ownership qualifications causes
all of the defaulted special functions of the enclosing union to be
defined as deleted, except when the member has an in-class initializer,
the default constructor isn't defined as deleted.

rdar://problem/34213306

Differential Revision: https://reviews.llvm.org/D57438

llvm-svn: 352949
2019-02-02 02:23:40 +00:00
Akira Hatanaka 957accaef0 [Sema][ObjC] Check whether a DelayedDiagnosticPool has been pushed
before adding a delayed diagnostic to DelayedDiagnostics.

This fixes an assertion failure in Sema::DelayedDiagnostics::add that
was caused by the changes made in r141037.

rdar://problem/42782323

llvm-svn: 351911
2019-01-23 00:55:48 +00:00
Akira Hatanaka 8e57b07f66 Distinguish `__block` variables that are captured by escaping blocks
from those that aren't.

This patch changes the way __block variables that aren't captured by
escaping blocks are handled:

- Since non-escaping blocks on the stack never get copied to the heap
  (see https://reviews.llvm.org/D49303), Sema shouldn't error out when
  the type of a non-escaping __block variable doesn't have an accessible
  copy constructor.

- IRGen doesn't have to use the specialized byref structure (see
  https://clang.llvm.org/docs/Block-ABI-Apple.html#id8) for a
  non-escaping __block variable anymore. Instead IRGen can emit the
  variable as a normal variable and copy the reference to the block
  literal. Byref copy/dispose helpers aren't needed either.

This reapplies r343518 after fixing a use-after-free bug in function
Sema::ActOnBlockStmtExpr where the BlockScopeInfo was dereferenced after
it was popped and deleted.

rdar://problem/39352313

Differential Revision: https://reviews.llvm.org/D51564

llvm-svn: 343542
2018-10-01 21:51:28 +00:00
Akira Hatanaka 3197484701 Revert r343518.
Bots are still failing.

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/24420
http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win/builds/12958

llvm-svn: 343531
2018-10-01 20:29:34 +00:00
Akira Hatanaka 2bf09ccfd5 Distinguish `__block` variables that are captured by escaping blocks
from those that aren't.

This patch changes the way __block variables that aren't captured by
escaping blocks are handled:

- Since non-escaping blocks on the stack never get copied to the heap
  (see https://reviews.llvm.org/D49303), Sema shouldn't error out when
  the type of a non-escaping __block variable doesn't have an accessible
  copy constructor.

- IRGen doesn't have to use the specialized byref structure (see
  https://clang.llvm.org/docs/Block-ABI-Apple.html#id8) for a
  non-escaping __block variable anymore. Instead IRGen can emit the
  variable as a normal variable and copy the reference to the block
  literal. Byref copy/dispose helpers aren't needed either.

This reapplies r341754, which was reverted in r341757 because it broke a
couple of bots. r341754 was calling markEscapingByrefs after the call to
PopFunctionScopeInfo, which caused the popped function scope to be
cleared out when the following code was compiled, for example:

$ cat test.m
struct A {
  id data[10];
};

void foo() {
  __block A v;
  ^{ (void)v; };
}

This commit calls markEscapingByrefs before calling PopFunctionScopeInfo
to prevent that from happening.

rdar://problem/39352313

Differential Revision: https://reviews.llvm.org/D51564

llvm-svn: 343518
2018-10-01 18:50:14 +00:00
Richard Smith 8baa50013c [cxx2a] P0614R1: Support init-statements in range-based for loops.
We don't yet support this for the case where a range-based for loop is
implicitly rewritten to an ObjC for..in statement.

llvm-svn: 343350
2018-09-28 18:44:09 +00:00
Aaron Puchert b081f44e17 Thread safety analysis: Handle ObjCIvarRefExpr in SExprBuilder::translate
Summary:
This imitates the code for MemberExpr.

Fixes PR38896.

Reviewers: aaron.ballman, delesley, lukasza, rjmccall

Reviewed By: delesley

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D52200

llvm-svn: 342600
2018-09-19 23:57:38 +00:00
Akira Hatanaka 9bd2452708 Revert r341754.
The commit broke a couple of bots:

http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win/builds/12347
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/7310

llvm-svn: 341757
2018-09-09 05:22:49 +00:00
Akira Hatanaka 2e00b98027 Distinguish `__block` variables that are captured by escaping blocks
from those that aren't.

This patch changes the way __block variables that aren't captured by
escaping blocks are handled:

- Since non-escaping blocks on the stack never get copied to the heap
  (see https://reviews.llvm.org/D49303), Sema shouldn't error out when
  the type of a non-escaping __block variable doesn't have an accessible
  copy constructor.

- IRGen doesn't have to use the specialized byref structure (see
  https://clang.llvm.org/docs/Block-ABI-Apple.html#id8) for a
  non-escaping __block variable anymore. Instead IRGen can emit the
  variable as a normal variable and copy the reference to the block
  literal. Byref copy/dispose helpers aren't needed either.

rdar://problem/39352313

Differential Revision: https://reviews.llvm.org/D51564

llvm-svn: 341754
2018-09-08 20:03:00 +00:00
Erik Pilkington ca019e745d [Sema] Relax a failing assert in TemplateArgumentLoc
Any of these template argument kinds can be represented with an expression, so
accept them in this constructor.

Patch by Balaji Iyer!

rdar://41459965

Differential revision: https://reviews.llvm.org/D49766

llvm-svn: 338338
2018-07-31 00:18:30 +00:00
Akira Hatanaka a6b5e00361 [Sema][ObjC] Warn when a method declared in a protocol takes a
non-escaping parameter but the implementation's method takes an escaping
parameter.

rdar://problem/39548196

Differential Revision: https://reviews.llvm.org/D49119

llvm-svn: 338189
2018-07-28 04:06:13 +00:00
Akira Hatanaka ea798aa7f5 [Sema] Produce diagnostics for attribute 'trivial_abi' that appears
after the closing brace of a class declaration.

Merge the two call sites of checkIllFormedTrivialABIStruct and sink it
into CheckCompletedCXXClass so that it is called after the attribute has
been attached to the CXXRecordDecl.

rdar://problem/40873297

llvm-svn: 335021
2018-06-19 05:04:44 +00:00
Richard Smith 7981004eb7 Improve diagnostics and error recovery for template name lookup.
For 'x::template y', consistently give a "no member named 'y' in 'x'"
diagnostic if there is no such member, and give a 'template keyword not
followed by a template' name error if there is such a member but it's not a
template. In the latter case, add a note pointing at the non-template.

Don't suggest inserting a 'template' keyword in 'X::Y<' if X is dependent
if the lookup of X::Y was actually not a dependent lookup and found only
non-templates.

llvm-svn: 332076
2018-05-11 02:43:08 +00:00
Akira Hatanaka ff6c4f3702 [Sema][ObjC] Ensure that the return type of an ObjC method is a complete
type.

Copy the code in ActOnStartOfFunctionDef that checks a function's return
type to ActOnStartOfObjCMethodDef. This fixes an assertion failure in
IRGen caused by an uninstantiated return type.

rdar://problem/38691818

llvm-svn: 329879
2018-04-12 06:01:41 +00:00
Akira Hatanaka 02914dc127 Add support for attribute 'trivial_abi'.
The 'trivial_abi' attribute can be applied to a C++ class, struct, or
union. It makes special functions of the annotated class (the destructor
and copy/move constructors) to be trivial for the purpose of calls and,
as a result, enables the annotated class or containing classes to be
passed or returned using the C ABI for the underlying type.

When a type that is considered trivial for the purpose of calls despite
having a non-trivial destructor (which happens only when the class type
or one of its subobjects is a 'trivial_abi' class) is passed to a
function, the callee is responsible for destroying the object.

For more background, see the discussions that took place on the mailing
list:

http://lists.llvm.org/pipermail/cfe-dev/2017-November/055955.html
http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20180101/thread.html#214043

rdar://problem/35204524

Differential Revision: https://reviews.llvm.org/D41039

llvm-svn: 324269
2018-02-05 20:23:22 +00:00
Aaron Ballman 8c20828b5c Re-commit r321223, which adds a printing policy to the ASTDumper.
This allows you to dump C++ code that spells bool instead of _Bool, leaves off the elaborated type specifiers when printing struct or class names, and other C-isms.

Fixes the -Wreorder issue and fixes the ast-dump-color.cpp test.

llvm-svn: 321310
2017-12-21 21:42:42 +00:00
Aaron Ballman 9d6501f6cd Reverting r321223 and its follow-up commit because of failing bots due to Misc/ast-dump-color.cpp.
llvm-svn: 321229
2017-12-20 23:17:29 +00:00
Aaron Ballman 207ee3d0a7 Add a printing policy to the ASTDumper.
This allows you to dump C++ code that spells bool instead of _Bool, leaves off the elaborated type specifiers when printing struct or class names, and other C-isms.

llvm-svn: 321223
2017-12-20 22:04:54 +00:00
Alex Lorenz bbe51d86ec [ObjC++] Don't warn about pessimizing move for __block variables
rdar://33316951

llvm-svn: 317620
2017-11-07 21:40:11 +00:00
Alex Lorenz c38ba6697f Typo correct the condition of 'do-while' before exiting its scope
rdar://35172419

llvm-svn: 316966
2017-10-30 22:55:11 +00:00
Akira Hatanaka bc1d56eafa [Sema][ObjC] Look for either objc_bridge or objc_bridge_mutable when
determining whether a RecordDecl is CFError.

CFErrorRef used to be declared with "objc_bridge(NSError)" but is now
declared with "objc_bridge_mutable(NSError)". Look for either when
checking whether a RecordDecl is CFError.

rdar://problem/35034779

llvm-svn: 316531
2017-10-24 23:38:14 +00:00
Volodymyr Sapsai 30680e9437 [Sema] Add support for flexible array members in Obj-C.
Allow Obj-C ivars with incomplete array type but only as the last ivar.
Also add a requirement for ivars that contain a flexible array member to
be at the end of class too. It is possible to add in a subclass another
ivar at the end but we'll emit a warning in this case. Also we'll emit a
warning if a variable sized ivar is declared in class extension or in
implementation because subclasses won't know they should avoid adding
new ivars.

In ARC incomplete array objects are treated as __unsafe_unretained so
require them to be marked as such.

Prohibit synthesizing ivars with flexible array members because order of
synthesized ivars is not obvious and tricky to control. Spelling out
ivar explicitly gives control to developers and helps to avoid surprises
with unexpected ivar ordering.

For C and C++ changed diagnostic to tell explicitly a field is not the
last one and point to the next field. It is not as useful as in Obj-C
but it is an improvement and it is consistent with Obj-C. For C for
unions emit more specific err_flexible_array_union instead of generic
err_field_incomplete.

rdar://problem/21054495

Reviewers: rjmccall, theraven

Reviewed By: rjmccall

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D38773

llvm-svn: 316381
2017-10-23 22:01:41 +00:00
Volodymyr Sapsai 43e6f7bee5 [Sema] Put nullability fix-it after the end of the pointer.
Fixes nullability fix-it for `id<SomeProtocol>`. With this change
nullability specifier is inserted after ">" instead of between
"id" and "<".

rdar://problem/34260995

Reviewers: jordan_rose, doug.gregor, ahatanak, arphaman

Reviewed By: jordan_rose

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D38327

llvm-svn: 314473
2017-09-28 23:18:49 +00:00
Akira Hatanaka 6c2dbc69a7 Add test cases that weren't committed in r313945.
llvm-svn: 313952
2017-09-22 01:54:36 +00:00