Merge pull request #10968 from cachemeifyoucan/eng/PR-155231696-release

[6.2] CAS validation improvements (#10966)

Author: akyrtzi

llvm/include/llvm/CAS/UnifiedOnDiskCache.h

@@ -155,6 +155,8 @@ class UnifiedOnDiskCache {
 
   Error validateActionCache();
 
+  OnDiskGraphDB *getUpstreamGraphDB() const { return UpstreamGraphDB; }
+
 private:
   UnifiedOnDiskCache();
 

llvm/lib/CAS/OnDiskCAS.cpp

@@ -90,13 +90,19 @@ class OnDiskCAS : public BuiltinCAS {
 
 void OnDiskCAS::print(raw_ostream &OS) const { DB->print(OS); }
 Error OnDiskCAS::validate(bool CheckHash) const {
-  return DB->validate(CheckHash, [](ArrayRef<ArrayRef<uint8_t>> Refs,
-                                    ArrayRef<char> Data,
-                                    SmallVectorImpl<uint8_t> &Result) {
+  auto Hasher = [](ArrayRef<ArrayRef<uint8_t>> Refs, ArrayRef<char> Data,
+                   SmallVectorImpl<uint8_t> &Result) {
     auto Hash = BuiltinObjectHasher<llvm::cas::builtin::HasherT>::hashObject(
         Refs, Data);
     Result.assign(Hash.begin(), Hash.end());
-  });
+  };
+
+  if (auto E = DB->validate(CheckHash, Hasher))
+    return E;
+  if (UniDB && UniDB->getUpstreamGraphDB())
+    return UniDB->getUpstreamGraphDB()->validate(CheckHash, Hasher);
+
+  return Error::success();
 }
 
 CASID OnDiskCAS::getID(ObjectRef Ref) const {

llvm/lib/CAS/UnifiedOnDiskCache.cpp

@@ -170,8 +170,6 @@ Error UnifiedOnDiskCache::validateActionCache() {
     };
     if (ID.getOpaqueData() == 0)
       return formatError("zero is not a valid ref");
-    if (!PrimaryGraphDB->containsObject(ID))
-      return formatError("cas does not contain ref");
     return Error::success();
   };
   if (Error E = PrimaryKVDB->validate(ValidateRef))