While working around a bug in certain standard library implementations,
we would try to diagnose the issue so that library implementors would
fix their code. However, we assumed an entity being initialized was
a non-static data member subobject when other circumstances are
possible.
This fixes PR24526.
llvm-svn: 245675
Without DR1579 implemented, the only case for -Wredundant-move is for a
parameter being returned with the same type as the function return type. Also
include a check to verify that the move constructor will be used by matching
nodes in the AST dump.
llvm-svn: 243594
Dependent types can throw off the analysis for these warnings, possibly giving
conflicting warnings and fix-its. Disabling the warning in template
instantiations will prevent this problem, and will still catch the
non-dependent cases in templates.
llvm-svn: 243538
error.
If the object being moved has a move constructor and a deleted copy constructor,
std::move is required, otherwise Clang will give a deleted constructor error.
llvm-svn: 243463
If we're returning a function parameter, copy elision isn't possible,
so we now warn for redundant move.
PR: 23819
Differential Revision: http://reviews.llvm.org/D11305
llvm-svn: 242600
The patch is generated using this command:
$ tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
work/llvm/tools/clang
To reduce churn, not touching namespaces spanning less than 10 lines.
llvm-svn: 240270
Based on previous discussion on the mailing list, clang currently lacks support
for C99 partial re-initialization behavior:
Reference: http://lists.cs.uiuc.edu/pipermail/cfe-dev/2013-April/029188.html
Reference: http://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_253.htm
This patch attempts to fix this problem.
Given the following code snippet,
struct P1 { char x[6]; };
struct LP1 { struct P1 p1; };
struct LP1 l = { .p1 = { "foo" }, .p1.x[2] = 'x' };
// this example is adapted from the example for "struct fred x[]" in DR-253;
// currently clang produces in l: { "\0\0x" },
// whereas gcc 4.8 produces { "fox" };
// with this fix, clang will also produce: { "fox" };
Differential Review: http://reviews.llvm.org/D5789
llvm-svn: 239446
The error has the form ... 'int' ... 'const int' ... dropped qualifiers. At
first glance, it appears that the const qualifier is added. Reverse the types
so that the second type is less qualified than the first.
llvm-svn: 237482
-Wpessimizing-move warns when a call to std::move would prevent copy elision
if the argument was not wrapped in a call. This happens when moving a local
variable in a return statement when the variable is the same type as the
return type or using a move to create a new object from a temporary object.
-Wredundant-move warns when an implicit move would already be made, so the
std::move call is not needed, such as when moving a local variable in a return
that is different from the return type.
Differential Revision: http://reviews.llvm.org/D7633
llvm-svn: 236075
We could probably make this work if we cared enough. However, we are
far outside any language rules at this point.
This fixes PR21834.
llvm-svn: 235818
r235046 turned "extern __declspec(selectany) int a;" from a declaration into
a definition to fix PR23242 (required for compatibility with mc.exe output).
However, this broke parsing Windows headers: A d3d11 headers contain something
like
struct SomeStruct {};
extern const __declspec(selectany) SomeStruct some_struct;
This is now a definition, and const objects either need an explicit default
ctor or an initializer so this errors out with
d3d11.h(1065,48) :
error: default initialization of an object of const type
'const CD3D11_DEFAULT' without a user-provided default constructor
(cl.exe just doesn't implement this rule, independent of selectany.)
To work around this, weaken this error into a warning for selectany decls
in microsoft mode, and recover with zero-initialization.
Doing this is a bit hairy since it adds a fixit on an error emitted
by InitializationSequence – this means it needs to build a correct AST, which
in turn means InitializationSequence::Failed() cannot return true when this
fixit is applied. As a workaround, the patch adds a fixit member to
InitializationSequence, and InitializationSequence::Perform() prints the
diagnostic if the fixit member is set right after its call to Diagnose.
That function is usually called when InitializationSequences are used –
InitListChecker::PerformEmptyInit() doesn't call it, but the InitListChecker
case never performs default-initialization, so this is technically OK.
This is the alternative, original fix for PR20208 that got reviewed in the
thread "[patch] Improve diagnostic on default-initializing const variables
(PR20208)". This change basically reverts r213725, adds the original fix for
PR20208, and makes the error a warning in Microsoft mode.
llvm-svn: 235166
Given something like 'int({}, 1)', we would try to emit a diagnostic
regarding the excess element in the scalar initializer. However, we
assumed that the initializer list had an element in it.
llvm-svn: 234565
invalidate lookup_iterators and lookup_results for some name within a
DeclContext if the lookup results for a *different* name change.
llvm-svn: 230121
subobject initialization is not possible, be sure to note the overall
initialization as having failed so that overload resolution knows that the
relevant candidate is not viable.
llvm-svn: 229353
always use the normal copy-initialization rules. Remove a special case that
tries to stay within the list initialization checker here; that makes us do the
wrong thing when list-initialization of an aggregate would not perform
aggregate initialization.
llvm-svn: 228897
based on whether "redundant" braces are ever reasonable as part of the
initialization of the entity, rather than whether the initialization is
"top-level". In passing, add a warning flag for it.
llvm-svn: 228896
initializer of the form {x}, where x is of type C or a type derived from C,
perform *non-list* initialization of the entity from x, but create a
CXXConstructExpr that knows that we used list-initialization syntax.
Plus some fixes to ensure we mangle correctly in this and related cases.
llvm-svn: 228276
... when the variable's type is a typedef of a ConstantArrayType. Just
look through the typedef (and any other sugar). We only use the
constant array type here to get the element count.
llvm-svn: 227115
clang currently calls MarkVTableUsed() for classes that get their virtual
methods called or that participate in a dynamic_cast. This is unnecessary,
since CodeGen only emits vtables when it generates constructor, destructor, and
vtt code. (*)
Note that Sema::MarkVTableUsed() doesn't cause the emission of a vtable.
Its main user-visible effect is that it instantiates virtual member functions
of template classes, to make sure that if codegen decides to write a vtable
all the entries in the vtable are defined.
While this shouldn't change the behavior of codegen (other than being faster),
it does make clang more permissive: virtual methods of templates (in particular
destructors) end up being instantiated less often. In particular, classes that
have members that are smart pointers to incomplete types will now get their
implicit virtual destructor instantiated less frequently. For example, this
used to not compile but does now compile:
template <typename T> struct OwnPtr {
~OwnPtr() { static_assert((sizeof(T) > 0), "TypeMustBeComplete"); }
};
class ScriptLoader;
struct Base { virtual ~Base(); };
struct Sub : public Base {
virtual void someFun() const {}
OwnPtr<ScriptLoader> m_loader;
};
void f(Sub *s) { s->someFun(); }
The more permissive behavior matches both gcc (where this is not often
observable, since in practice most things with virtual methods have a key
function, and Sema::DefineUsedVTables() skips vtables for classes with key
functions) and cl (which is my motivation for this change) – this fixes
PR20337. See this issue and the review thread for some discussions about
optimizations.
This is similar to r213109 in spirit. r225761 was a prerequisite for this
change.
Various tests relied on "a->f()" marking a's vtable as used (in the sema
sense), switch these to just construct a on the stack. This forces
instantiation of the implicit constructor, which will mark the vtable as used.
(*) The exception is -fapple-kext mode: In this mode, qualified calls to
virtual functions (`a->Base::f()`) still go through the vtable, and since the
vtable pointer off this doesn't point to Base's vtable, this needs to reference
Base's vtable directly. To keep this working, keep referencing the vtable for
virtual calls in apple kext mode.
llvm-svn: 227073
Only the first two items for now, changing Sections 8.5.4 [dcl.init.list] paragraph 3 and 13.3.1.7 [over.match.list] paragraph 1,
so that defining class objects and character arrays using uniform initialization syntax is actually treated as list initialization
and before it is treated aggregate initialization.
llvm-svn: 227022
Specifically, when we have this situation:
struct A {
template <typename T> struct B {
int m1 = sizeof(A);
};
B<int> m2;
};
We can't parse m1's initializer eagerly because we need A to be
complete. Therefore we wait until the end of A's class scope to parse
it. However, we can trigger instantiation of B before the end of A,
which will attempt to instantiate the field decls eagerly, and it would
build a bad field decl instantiation that said it had an initializer but
actually lacked one.
Fixed by deferring instantiation of default member initializers until
they are needed during constructor analysis. This addresses a long
standing FIXME in the code.
Fixes PR19195.
Reviewed By: rsmith
Differential Revision: http://reviews.llvm.org/D5690
llvm-svn: 222192
The check for unnamed members was intended to skip unnamed bitfields,
but it ended up skipping unnamed structs. This lead to an assertion in
IRGen.
llvm-svn: 221818
before retrying the initialization to produce diagnostics. Otherwise, we may
fail to produce any diagnostics, and silently produce invalid AST in a -Asserts
build. Also add a note to this codepath to make it more clear why we were
trying to create a temporary.
llvm-svn: 217197
Clang used a custom implementation of lookup when handling designated
initializers. The custom code was not particularly optimized and relied
on standard lookup for typo-correction anyway.
This custom code has to go, it doesn't properly support MSVC-style
anonymous structs embedded inside other records; replace it with the
typo-correction path.
This has the side effect of speeding up semantic handling of the fields
for a designated initializer while simplifying the code at the same
time.
This fixes PR20573.
Differential Revision: http://reviews.llvm.org/D4839
llvm-svn: 215372
or a class derived from T. We already supported this when initializing
_Atomic(T) from T for most (and maybe all) other reasonable values of T.
llvm-svn: 214390
This tweaks the diagnostic wording slighly, and adds a fixit on a note.
An alternative would be to add the fixit directly on the diagnostic, see
the review thread linked to from the bug for a few notes on that approach.
llvm-svn: 213725
ExtWarn/Warnings. Mostly the name of the warning was changed to match the
semantics, but in the PR20356 cases, the warning was about valid code, so the
diagnostic was changed from ExtWarn to Warning instead.
llvm-svn: 213443
If, during the initial parse of a template, we perform aggregate initialization
and form an implicit value initialization for an array type, then when we come
to instantiate the template and redo the initialization step, we would try to
match the implicit value initialization up against an array *element*, not to
the complete array.
Remarkably, we've had this bug since ~the dawn of time, but only noticed it
recently.
llvm-svn: 213332
-- a constructor list initialization that unpacked an initializer list into
constructor arguments and
-- a list initialization that created as std::initializer_list and passed it
as the first argument to a constructor
in the AST. Use this flag while instantiating templates to provide the right
semantics for the resulting initialization.
llvm-svn: 213224
constructor (and pass it an implicitly-generated std::initializer_list object),
be sure to mark the resulting construction as list-initialization. This fixes
an assert in template instantiation where we previously thought we'd got direct
non-list initialization without any parentheses.
llvm-svn: 213201
Nick Lewycky