Essentially, as a base class constructor does not construct virtual bases, such
a constructor for an abstract class does not need the corresponding base class
construction to be valid, and likewise for destructors.
This creates an awkward situation: clang will sometimes generate references to
the complete object and deleting destructors for an abstract class (it puts
them in the construction vtable for a derived class). But we can't generate a
"correct" version of these because we can't generate references to base class
constructors any more (if they're template specializations, say, we might not
have instantiated them and can't assume any other TU will emit a copy).
Fortunately, we don't need to, since no correct program can ever invoke them,
so instead emit symbols that just trap.
We should stop emitting references to these symbols, but still need to emit
definitions for compatibility.
llvm-svn: 296275
instantiation.
In preparation for converting the template stack to a more general context
stack (so we can include context notes for other kinds of context).
llvm-svn: 295686
Add a warning for shadowed variables across records. Referencing a
shadow'ed variable may not give the desired variable. Add an optional
warning for the shadowing.
Patch by James Sun!
llvm-svn: 294401
We model deduction-guides as functions with a new kind of name that identifies
the template whose deduction they guide; the bulk of this patch is adding the
new name kind. This gives us a clean way to attach an extensible list of guides
to a class template in a way that doesn't require any special handling in AST
files etc (and we're going to need these functions we come to performing
deduction).
llvm-svn: 294266
Fixes a regression introduced in r291045, which would lead to link
errors. While we should no longer encounter unparsed or uninstantiated
default arguments in this codepath, we still need to call
CheckCXXDefaultArgExpr to mark the default argument expressions as
ODR-used.
llvm-svn: 291453
This implements something like the current direction of DR1581: we use a narrow
syntactic check to determine the set of places where a constant expression
could be evaluated, and only instantiate a constexpr function or variable if
it's referenced in one of those contexts, or is odr-used.
It's not yet clear whether this is the right set of syntactic locations; we
currently consider all contexts within templates that would result in odr-uses
after instantiation, and contexts within list-initialization (narrowing
conversions take another victim...), as requiring instantiation. We could in
principle restrict the former cases more (only const integral / reference
variable initializers, and contexts in which a constant expression is required,
perhaps). However, this is sufficient to allow us to accept libstdc++ code,
which relies on GCC's behavior (which appears to be somewhat similar to this
approach).
llvm-svn: 291318
Summary:
Replace some old code that probably pre-dated the change to delay
emission of dllexported code until after the closing brace of the
outermost record type. Only uninstantiated default argument expressions
need to be handled now. It is enough to instantiate default argument
expressions when instantiating dllexported default ctors. This also
fixes some double-diagnostic issues in this area.
Fixes PR31500
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D28274
llvm-svn: 291045
This change introduces UsingPackDecl as a marker for the set of UsingDecls
produced by pack expansion of a single (unresolved) using declaration. This is
not strictly necessary (we just need to be able to map from the original using
declaration to its expansions somehow), but it's useful to maintain the
invariant that each declaration reference instantiates to refer to one
declaration.
This is a re-commit of r290080 (reverted in r290092) with a fix for a
use-after-lifetime bug.
llvm-svn: 290203
This change introduces UsingPackDecl as a marker for the set of UsingDecls
produced by pack expansion of a single (unresolved) using declaration. This is
not strictly necessary (we just need to be able to map from the original using
declaration to its expansions somehow), but it's useful to maintain the
invariant that each declaration reference instantiates to refer to one
declaration.
llvm-svn: 290080
* a dependent non-type using-declaration within a function template can be
valid, as it can refer to an enumerator, so don't reject it in the template
definition
* we can partially substitute into a dependent using-declaration if it appears
within a (local class in a) generic lambda within a function template, which
means an UnresolvedUsing*Decl doesn't necessarily instantiate to a UsingDecl.
llvm-svn: 290071
copy constructors of classes with array members, instead using
ArrayInitLoopExpr to represent the initialization loop.
This exposed a bug in the static analyzer where it was unable to differentiate
between zero-initialized and unknown array values, which has also been fixed
here.
llvm-svn: 289618
tuple-like interpretation of decomposition declaration even if there is no
::value member. We already did this, anticipating this resolution, just update
comments and tweak a testcase.
llvm-svn: 289021
Our -Wweak-vtables diagnostic is powered by our key function
calculation, which checks if key functions are enabled. We won't find
any key functions in C++ ABIs that lack key functions, so -Wweak-vtables
was warning on every dynamic class before this change. So, turn off this
warning in ABIs without key functions.
Addresses PR31220
llvm-svn: 288850
Summary:
Similar to r288685.
getExceptionSpec returned structure with pointers to temporarily object created
by computeImplicitExceptionSpec.
Reviewers: rsmith
Subscribers: aizatsky, cfe-commits
Differential Revision: https://reviews.llvm.org/D27422
llvm-svn: 288689
Summary:
We don't need a side table in ASTContext to hold CXXDefaultArgExprs. The
important part of building the CXXDefaultArgExprs was to ODR use the
default argument expressions, not to make AST nodes. Refactor the code
to only check the default argument, and remove the side table in
ASTContext which wasn't being serialized.
Fixes PR31121
Reviewers: thakis, rsmith, majnemer
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D27007
llvm-svn: 287774
This is needed because whether the constructor is deleted can control whether
we pass structs by value directly.
To fix this properly we probably want a more direct way for CodeGen to ask
whether the constructor was deleted.
Fixes PR31049.
Differential Revision: https://reviews.llvm.org/D26822
llvm-svn: 287600
Summary:
This changes pointers to cached tokens for default arguments in C++ from raw pointers to unique_ptrs. There was a fixme in the code where the cached tokens are created about using a smart pointer.
The change is straightforward, though I did have to track down and fix a memory corruption caused by the change. memcpy was being used to copy parameter information. This duplicated the unique_ptr, which led to the cached token buffer being deleted prematurely.
Patch by David Tarditi!
Reviewers: malcolm.parsons
Subscribers: arphaman, malcolm.parsons, cfe-commits
Differential Revision: https://reviews.llvm.org/D26435
llvm-svn: 287241
This commit improves the "must have C++ linkage" error diagnostics that are
emitted for C++ declarations like templates and literal operators by adding an
additional note that points to the appropriate extern "C" linkage specifier.
rdar://19021120
Differential Revision: https://reviews.llvm.org/D26189
llvm-svn: 285823
Summary: When merging definitions with ModulesLocalVisibility enabled it's important to make deleted definitions implicitly inline, otherwise they'll be diagnosed as a redefinition.
Reviewers: silvas, manmanren, rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D26143
llvm-svn: 285655
If two modules contain duplicate class definitions the lookup result can contain
more than 2 elements. Sift the lookup results until we find a field decl.
It is not necessary to do ODR checks in place as they done elsewhere.
This should fix issues when compiling with libstdc++ 5.2 and 6.2.
Patch developed in collaboration with Richard Smith!
llvm-svn: 285184
