Summary:
Trying to use structure binding with a structure that doesn't implement
std::tuple_size, should unpack the data members. When the struct is a
template though, clang might hit an assertion (if the type has not been
completed before), because CXXRecordDecl::DefinitionData is nullptr.
This commit fixes the problem by completing the type while trying to
decompose the structured binding.
The ICE happens in real world code, for example, when trying to iterate
a protobuf generated map with a range-based for loop and structure
bindings (because google::protobuf::MapPair is a template and doesn't
support std::tuple_size).
Reported-by: nicholas.sun@nlsun.com
Patch by Daniele Di Proietto
Reviewers: #clang, rsmith
Reviewed By: #clang, rsmith
Subscribers: cpplearner, Rakete1111, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D56974
llvm-svn: 352323
In order to match our mangling scheme, use a different set of numbers for
decomposition declarations, and consider all binding names when forming the
numbering. This does not yet affect any mangled names we produce, because
local decomposition declarations can't yet have linkage, but a C++ standard
proposal to change that is currently being processed.
llvm-svn: 331692
Most code paths would already bail out in this case, but certain paths,
particularly overload resolution and typo correction, would not. Carrying on
with an invalid declaration could in some cases result in crashes due to
downstream code relying on declaration invariants that are not necessarily
met for invalid declarations, and in other cases just resulted in undesirable
follow-on diagnostics.
llvm-svn: 291030
decomposition declarations.
There are a couple of things in the wording that seem strange here:
decomposition declarations are permitted at namespace scope (which we partially
support here) and they are permitted as the declaration in a template (which we
reject).
llvm-svn: 276492
Nicolas Lesser