[clang] [clang][ssaf] Implement TUSummaryBuilder with test infrastructure (PR #181220)

[Aviral Goel via cfe-commits]

================
@@ -9,10 +9,47 @@
 #ifndef LLVM_CLANG_ANALYSIS_SCALABLE_TUSUMMARY_TUSUMMARYBUILDER_H
 #define LLVM_CLANG_ANALYSIS_SCALABLE_TUSUMMARY_TUSUMMARYBUILDER_H
 
+#include "clang/Analysis/Scalable/Model/EntityId.h"
+#include "clang/Analysis/Scalable/TUSummary/EntitySummary.h"
+#include <memory>
+#include <utility>
+
 namespace clang::ssaf {
 
+class EntityName;
+class TUSummary;
+
 class TUSummaryBuilder {
-  // Empty for now.
+public:
+  explicit TUSummaryBuilder(TUSummary &Summary) : Summary(Summary) {}
+
+  /// Add an entity to the summary and return its EntityId.
+  /// If the entity already exists, returns the existing ID (idempotent).
+  EntityId addEntity(const EntityName &E);
+
+  /// Associate the \p Data EntitySummary with the \p Entity.
+  /// This consumes the \p Data only if \p Entity wasn't associated yet with the
+  /// same kind of EntitySummary.
+  /// \returns a pointer to the EntitySummary and whether it inserted or not.
+  template <typename ConcreteEntitySummary,
+            DerivesFromEntitySummary<ConcreteEntitySummary> * = nullptr>
+  std::pair<EntitySummary *, bool>
+  addSummary(EntityId Entity, std::unique_ptr<ConcreteEntitySummary> &&Data) {
+    std::unique_ptr<EntitySummary> TypeErasedData = std::move(Data);
+    auto [It, Inserted] = addSummaryImpl(Entity, std::move(TypeErasedData));
+    // Move it back on failue to keep the `Data` unconsumed.
+    if (!Inserted) {
+      Data = std::unique_ptr<ConcreteEntitySummary>(
+          static_cast<ConcreteEntitySummary *>(TypeErasedData.release()));
+    }
+    return {It, Inserted};
+  }
----------------
aviralg wrote:

When the client adds a conflicting summary, the function moves the data back to keep it unconsumed. That way, the argument to the `Data` parameter remains valid on the client side.

https://github.com/llvm/llvm-project/pull/181220