Redeclare Objective-C property accessors inside the ObjCImplDecl in which they are synthesized.

This patch is motivated by (and factored out from)
https://reviews.llvm.org/D66121 which is a debug info bugfix. Starting
with DWARF 5 all Objective-C methods are nested inside their
containing type, and that patch implements this for synthesized
Objective-C properties.

1. SemaObjCProperty populates a list of synthesized accessors that may
   need to inserted into an ObjCImplDecl.

2. SemaDeclObjC::ActOnEnd inserts forward-declarations for all
   accessors for which no override was provided into their
   ObjCImplDecl. This patch does *not* synthesize AST function
   *bodies*. Moving that code from the static analyzer into Sema may
   be a good idea though.

3. Places that expect all methods to have bodies have been updated.

I did not update the static analyzer's inliner for synthesized
properties to point back to the property declaration (see
test/Analysis/Inputs/expected-plists/nullability-notes.m.plist), which
I believed to be more bug than a feature.

Differential Revision: https://reviews.llvm.org/D68108

rdar://problem/53782400

1 files changed, 5 insertions, 0 deletions

diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
index 48e8b615158..ada5d7551d7 100644
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -629,6 +629,11 @@ bool CursorVisitor::VisitDeclContext(DeclContext *DC) {
     Decl *D = *I;
     if (D->getLexicalDeclContext() != DC)
       continue;
+    // Filter out synthesized property accessor redeclarations.
+    if (isa<ObjCImplDecl>(DC))
+      if (auto *OMD = dyn_cast<ObjCMethodDecl>(D))
+        if (OMD->isSynthesizedAccessorStub())
+          continue;
     const Optional<bool> V = handleDeclForVisitation(D);
     if (!V.hasValue())
       continue;