Change: make nlohmann a mandatory library to build OpenTTD (#11235)

.github/workflows/ci-build.yml

@@ -77,20 +77,20 @@ jobs:
         - name: Clang
           compiler: clang
           cxxcompiler: clang++
-          libraries: libsdl2-dev nlohmann-json3-dev
+          libraries: libsdl2-dev
         - name: GCC - SDL2
           compiler: gcc
           cxxcompiler: g++
-          libraries: libsdl2-dev nlohmann-json3-dev
+          libraries: libsdl2-dev
         - name: GCC - SDL1.2
           compiler: gcc
           cxxcompiler: g++
-          libraries: libsdl1.2-dev nlohmann-json3-dev
+          libraries: libsdl1.2-dev
         - name: GCC - Dedicated
           compiler: gcc
           cxxcompiler: g++
           extra-cmake-parameters: -DOPTION_DEDICATED=ON -DCMAKE_CXX_FLAGS_INIT="-DRANDOM_DEBUG" -DCMAKE_DISABLE_PRECOMPILE_HEADERS=ON
-          # Compile without SDL / SDL2 / nlohmann-json, as that should compile fine too.
+          # Compile without SDL / SDL2, as that should compile fine too.
 
     name: Linux (${{ matrix.name }})
 
@@ -118,6 +118,7 @@ jobs:
           libicu-dev \
           liblzma-dev \
           liblzo2-dev \
+          nlohmann-json3-dev \
           ${{ matrix.libraries }} \
           zlib1g-dev \
           # EOF

CMakeLists.txt

@@ -119,12 +119,13 @@ endif()
 set(CMAKE_THREAD_PREFER_PTHREAD YES)
 # Make sure we have Threads available.
 find_package(Threads REQUIRED)
+# nlohmann is used for all our JSON needs.
+find_package(nlohmann_json REQUIRED)
 
 find_package(ZLIB)
 find_package(LibLZMA)
 find_package(LZO)
 find_package(PNG)
-find_package(nlohmann_json)
 
 if(WIN32 OR EMSCRIPTEN)
     # Windows uses WinHttp for HTTP requests.
@@ -309,7 +310,7 @@ link_package(PNG TARGET PNG::PNG ENCOURAGED)
 link_package(ZLIB TARGET ZLIB::ZLIB ENCOURAGED)
 link_package(LIBLZMA TARGET LibLZMA::LibLZMA ENCOURAGED)
 link_package(LZO)
-link_package(nlohmann_json ENCOURAGED)
+link_package(nlohmann_json)
 
 if(NOT WIN32 AND NOT EMSCRIPTEN)
     link_package(CURL ENCOURAGED)

COMPILING.md

@@ -4,7 +4,7 @@
 
 OpenTTD makes use of the following external libraries:
 
-- (encouraged) nlohmann-json: JSON handling
+- (required) nlohmann-json: JSON handling
 - (encouraged) breakpad: creates minidumps on crash
 - (encouraged) zlib: (de)compressing of old (0.3.0-1.0.5) savegames, content downloads,
    heightmaps

src/network/network_survey.cpp

@@ -31,9 +31,7 @@
 #include "../base_media_base.h"
 #include "../blitter/factory.hpp"
 
-#ifdef WITH_NLOHMANN_JSON
 #include <nlohmann/json.hpp>
-#endif /* WITH_NLOHMANN_JSON */
 
 #include "../safeguards.h"
 
@@ -41,8 +39,6 @@ extern std::string _savegame_id;
 
 NetworkSurveyHandler _survey = {};
 
-#ifdef WITH_NLOHMANN_JSON
-
 NLOHMANN_JSON_SERIALIZE_ENUM(NetworkSurveyHandler::Reason, {
 	{NetworkSurveyHandler::Reason::PREVIEW, "preview"},
 	{NetworkSurveyHandler::Reason::LEAVE, "leave"},
@@ -334,8 +330,6 @@ std::string SurveyMemoryToText(uint64_t memory)
 	return fmt::format("{} MiB", Ceil(memory, 4));
 }
 
-#endif /* WITH_NLOHMANN_JSON */
-
 /**
  * Create the payload for the survey.
  *
@@ -345,9 +339,6 @@ std::string SurveyMemoryToText(uint64_t memory)
  */
 std::string NetworkSurveyHandler::CreatePayload(Reason reason, bool for_preview)
 {
-#ifndef WITH_NLOHMANN_JSON
-	return "";
-#else
 	nlohmann::json survey;
 
 	survey["schema"] = NETWORK_SURVEY_VERSION;
@@ -381,7 +372,6 @@ std::string NetworkSurveyHandler::CreatePayload(Reason reason, bool for_preview)
 	/* For preview, we indent with 4 whitespaces to make things more readable. */
 	int indent = for_preview ? 4 : -1;
 	return survey.dump(indent);
-#endif /* WITH_NLOHMANN_JSON */
 }
 
 /**

src/network/network_survey.h

@@ -36,12 +36,7 @@ public:
 
 	constexpr static bool IsSurveyPossible()
 	{
-#ifndef WITH_NLOHMANN_JSON
-		/* Without JSON library, we cannot send a payload; so we disable the survey. */
-		return false;
-#else
 		return true;
-#endif /* WITH_NLOHMANN_JSON */
 	}
 
 private:

src/os/macosx/survey_osx.cpp

@@ -7,8 +7,6 @@
 
 /** @file survey_osx.cpp OSX implementation of OS-specific survey information. */
 
-#ifdef WITH_NLOHMANN_JSON
-
 #include "../../stdafx.h"
 
 #include "../../3rdparty/fmt/format.h"
@@ -38,5 +36,3 @@ void SurveyOS(nlohmann::json &json)
 	json["memory"] = SurveyMemoryToText(MacOSGetPhysicalMemory());
 	json["hardware_concurrency"] = std::thread::hardware_concurrency();
 }
-
-#endif /* WITH_NLOHMANN_JSON */

src/os/unix/survey_unix.cpp

@@ -7,8 +7,6 @@
 
 /** @file survey_unix.cpp Unix implementation of OS-specific survey information. */
 
-#ifdef WITH_NLOHMANN_JSON
-
 #include "../../stdafx.h"
 
 #include <nlohmann/json.hpp>
@@ -38,5 +36,3 @@ void SurveyOS(nlohmann::json &json)
 	json["memory"] = SurveyMemoryToText(pages * page_size);
 	json["hardware_concurrency"] = std::thread::hardware_concurrency();
 }
-
-#endif /* WITH_NLOHMANN_JSON */

src/os/windows/survey_win.cpp

@@ -7,8 +7,6 @@
 
 /** @file survey_win.cpp Windows implementation of OS-specific survey information. */
 
-#ifdef WITH_NLOHMANN_JSON
-
 #include "../../stdafx.h"
 
 #include "../../3rdparty/fmt/format.h"
@@ -37,5 +35,3 @@ void SurveyOS(nlohmann::json &json)
 	json["memory"] = SurveyMemoryToText(status.ullTotalPhys);
 	json["hardware_concurrency"] = std::thread::hardware_concurrency();
 }
-
-#endif /* WITH_NLOHMANN_JSON */