[PATCH] D118525: [modules] Merge ObjC interface ivars with anonymous types.

[Volodymyr Sapsai via Phabricator via cfe-commits]

vsapsai created this revision.
vsapsai added reviewers: ahatanak, rsmith.
vsapsai added a project: clang-modules.
Herald added a subscriber: ributzka.
vsapsai requested review of this revision.

Without the fix ivars with anonymous types can trigger errors like

> error: 'TestClass::structIvar' from module 'Target' is not present in definition of 'TestClass' provided earlier
> [...]
> note: declaration of 'structIvar' does not match

It happens because types of ivars from different modules are considered
to be different. And it is caused by not merging anonymous `TagDecl`
from different modules.

To fix that I've changed `serialization::needsAnonymousDeclarationNumber`
to handle anonymous `TagDecl` inside `ObjCInterfaceDecl`. But that's not
sufficient as C code inside `ObjCInterfaceDecl` doesn't use interface
decl as a decl context but switches to its parent (TranslationUnit in
most cases).  I'm changing that to make `ObjCContainerDecl` the lexical
decl context but keeping the semantic decl context intact.  Though for
anonymous `TagDecl` `ObjCContainerDecl` is both a lexical and a semantic
decl context now. But it doesn't affect the lookup because such
`TagDecl`s don't have a name to use for the lookup.

Test "check-dup-decls-inside-objc.m" doesn't reflect a change in
functionality but captures the existing behavior to prevent regressions.

rdar://85563013


Repository:
  rC Clang

https://reviews.llvm.org/D118525

Files:
  clang/lib/Parse/ParseObjc.cpp
  clang/lib/Sema/SemaDecl.cpp
  clang/lib/Serialization/ASTCommon.cpp
  clang/lib/Serialization/ASTReaderDecl.cpp
  clang/test/AST/ast-dump-decl.mm
  clang/test/Modules/merge-anon-record-definition-in-objc.m
  clang/test/SemaObjC/check-dup-decls-inside-objc.m

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