Add 'json4cpp/' from commit '9a737481aed085fd289f82dff1fa8c3c66627a7e'

git-subtree-dir: json4cpp
git-subtree-mainline: 292baed7ac0cf84263263966ed32ed113cae857f
git-subtree-split: 9a737481aed085fd289f82dff1fa8c3c66627a7e

1 files changed, 70 insertions, 0 deletions

diff --git a/json4cpp/tests/src/fuzzer-parse_json.cpp b/json4cpp/tests/src/fuzzer-parse_json.cpp
new file mode 100644
index 0000000000..59a278c7bd
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+++ b/json4cpp/tests/src/fuzzer-parse_json.cpp
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+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.12.0
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
+/*
+This file implements a parser test suitable for fuzz testing. Given a byte
+array data, it performs the following steps:
+
+- j1 = parse(data)
+- s1 = serialize(j1)
+- j2 = parse(s1)
+- s2 = serialize(j2)
+- assert(s1 == s2)
+
+The provided function `LLVMFuzzerTestOneInput` can be used in different fuzzer
+drivers.
+*/
+
+#include <iostream>
+#include <sstream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+// see http://llvm.org/docs/LibFuzzer.html
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
+{
+    try
+    {
+        // step 1: parse input
+        json const j1 = json::parse(data, data + size);
+
+        try
+        {
+            // step 2: round trip
+
+            // first serialization
+            std::string const s1 = j1.dump();
+
+            // parse serialization
+            json const j2 = json::parse(s1);
+
+            // second serialization
+            std::string const s2 = j2.dump();
+
+            // serializations must match
+            assert(s1 == s2);
+        }
+        catch (const json::parse_error&)
+        {
+            // parsing a JSON serialization must not fail
+            assert(false);
+        }
+    }
+    catch (const json::parse_error&)
+    {
+        // parse errors are ok, because input may be random bytes
+    }
+    catch (const json::out_of_range&)
+    {
+        // out of range errors may happen if provided sizes are excessive
+    }
+
+    // return 0 - non-zero return values are reserved for future use
+    return 0;
+}