[clang] [clang][ssaf] Implement JSONFormat (PR #180021)

[Balázs Benics via cfe-commits]

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+//===- unittests/Analysis/Scalable/JSONFormatTest.cpp --------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Unit tests for SSAF JSON serialization format reading and writing.
+//
+//===----------------------------------------------------------------------===//
+
+
+#include "clang/Analysis/Scalable/Serialization/JSONFormat.h"
+#include "clang/Analysis/Scalable/TUSummary/TUSummary.h"
+#include "llvm/ADT/IntrusiveRefCntPtr.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/Registry.h"
+#include "llvm/Support/VirtualFileSystem.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Testing/Support/Error.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include <memory>
+#include <string>
+#include <vector>
+
+using namespace clang::ssaf;
+using namespace llvm;
+using ::testing::AllOf;
+using ::testing::HasSubstr;
+
+namespace {
+
+// ============================================================================
+// Test Analysis - Simple analysis for testing JSON serialization
+// ============================================================================
+
+struct TestAnalysis : EntitySummary {
+  TestAnalysis() : EntitySummary(SummaryName("test_summary")) {}
+  std::vector<std::pair<EntityId, EntityId>> Pairs;
+};
+
+static json::Object
+serializeTestAnalysis(const EntitySummary &Summary,
+                      const JSONFormat::EntityIdConverter &Converter) {
+  const auto &TA = static_cast<const TestAnalysis &>(Summary);
+  json::Array PairsArray;
+  for (const auto &[First, Second] : TA.Pairs) {
+    PairsArray.push_back(json::Object{
+        {"first", Converter.toJSON(First)},
+        {"second", Converter.toJSON(Second)},
+    });
+  }
+  return json::Object{{"pairs", std::move(PairsArray)}};
+}
+
+static Expected<std::unique_ptr<EntitySummary>>
+deserializeTestAnalysis(const json::Object &Obj, EntityIdTable &IdTable,
+                        const JSONFormat::EntityIdConverter &Converter) {
+  auto Result = std::make_unique<TestAnalysis>();
+  const json::Array *PairsArray = Obj.getArray("pairs");
+  if (!PairsArray)
+    return createStringError(inconvertibleErrorCode(),
+                             "missing or invalid field 'pairs'");
+  for (const auto &[Index, Value] : llvm::enumerate(*PairsArray)) {
+    const json::Object *Pair = Value.getAsObject();
+    if (!Pair)
+      return createStringError(
+          inconvertibleErrorCode(),
+          "pairs element at index %zu is not a JSON object", Index);
+    auto FirstOpt = Pair->getInteger("first");
+    if (!FirstOpt)
+      return createStringError(
+          inconvertibleErrorCode(),
+          "missing or invalid 'first' field at index '%zu'", Index);
----------------
steakhal wrote:

Currently this code is dead. Maybe we could craft a test to exercise it.

https://github.com/llvm/llvm-project/pull/180021