When two modules contain interfaces with the same name, check the
definitions are equivalent and diagnose if they are not.
Differential Revision: https://reviews.llvm.org/D140073
With the old approach we were updating `ObjCInterfaceType.Decl` to the
last encountered definition. But during loading modules
`ASTDeclReader::VisitObjCInterfaceDecl` keeps the *first* encountered
definition. So with multiple definitions imported there would be a
disagreement between expected definition in `ObjCInterfaceType.Decl` and
actual definition `ObjCInterfaceDecl::getDefinition` which can lead to
incorrect diagnostic.
Fix by not tracking definition in `ObjCInterfaceType` explicitly but by
getting it from redeclaration chain.
Partially reverted 919fc50034b44c48aae8b80283f253ec2ee17f45 keeping the
modified test case as the correct behavior is achieved in a different
way.
Differential Revision: https://reviews.llvm.org/D110452
Fix a few bugs where we would fail to properly determine header to
module correspondence when determining whether to suggest a #include or
import, and suggest a #include more often in language modes where there
is no import syntax. Generally, if the target is in a header with
include guards or #pragma once, we should suggest either #including or
importing that header, and not importing a module that happens to
textually include it.
In passing, improve the notes we attach to the corresponding
diagnostics: calling an entity that we couldn't see "previous" is
confusing.
Summary:
Otherwise the definition (first found) for ObjCInterfaceDecl's might
precede the module one, which will eventually lead to crash, since
diagnoseMissingImport needs one coming from a module.
This behavior changed after Richard's r342018, which started to look
into the definition of ObjCInterfaceDecls.
rdar://problem/49237144
Reviewers: rsmith, arphaman
Subscribers: jkorous, dexonsmith, ributzka, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D66982
llvm-svn: 372039
