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, 10 insertions, 0 deletions

diff --git a/clang/lib/Analysis/BodyFarm.cpp b/clang/lib/Analysis/BodyFarm.cpp
index 43f9e715b3d..be065ed9330 100644
--- a/clang/lib/Analysis/BodyFarm.cpp
+++ b/clang/lib/Analysis/BodyFarm.cpp
@@ -830,6 +830,16 @@ Stmt *BodyFarm::getBody(const ObjCMethodDecl *D) {
   if (D->param_size() != 0)
     return nullptr;
 
+  // If the property was defined in an extension, search the extensions for
+  // overrides.
+  const ObjCInterfaceDecl *OID = D->getClassInterface();
+  if (dyn_cast<ObjCInterfaceDecl>(D->getParent()) != OID)
+    for (auto *Ext : OID->known_extensions()) {
+      auto *OMD = Ext->getInstanceMethod(D->getSelector());
+      if (OMD && !OMD->isImplicit())
+        return nullptr;
+    }
+
   Val = createObjCPropertyGetter(C, Prop);
 
   return Val.getValue();