Fixes for Project Manager on Linux

- Fix error with EngineFinder using the wrong path to locate project.json
- Simplified and expanded clang detection
- Remove forcing clang-12 for builds and will rely on the new cmake detection of clang by default

Signed-off-by: Steve Pham <82231385+spham-amzn@users.noreply.github.com>

Code/Tools/ProjectManager/Platform/Linux/ProjectBuilderWorker_linux.cpp

@@ -23,25 +23,11 @@ namespace O3DE::ProjectManager
         QString cmakeGenerator = (whichNinjaResult.IsSuccess()) ? "Ninja Multi-Config" : "Unix Makefiles";
         bool    compileProfileOnBuild = (whichNinjaResult.IsSuccess());
 
-        // On Linux the default compiler is gcc. For O3DE, it is clang, so we need to specify the version of clang that is detected
-        // in order to get the compiler option.
-        auto compilerOptionResult = ProjectUtils::FindSupportedCompilerForPlatform();
-        if (!compilerOptionResult.IsSuccess())
-        {
-            return AZ::Failure(compilerOptionResult.GetError());
-        }
-        auto clangCompilers = compilerOptionResult.GetValue().split('|');
-        AZ_Assert(clangCompilers.length()==2, "Invalid clang compiler pair specification");
-
-        QString clangCompilerOption = clangCompilers[0];
-        QString clangPPCompilerOption = clangCompilers[1];
         QString targetBuildPath = QDir(m_projectInfo.m_path).filePath(ProjectBuildPathPostfix);
         QStringList generateProjectArgs = QStringList{ProjectCMakeCommand,
                                                       "-B", ProjectBuildPathPostfix,
                                                       "-S", ".",
                                                       QString("-G%1").arg(cmakeGenerator),
-                                                      QString("-DCMAKE_C_COMPILER=").append(clangCompilerOption),
-                                                      QString("-DCMAKE_CXX_COMPILER=").append(clangPPCompilerOption),
                                                       QString("-DLY_3RDPARTY_PATH=").append(thirdPartyPath)};
         if (!compileProfileOnBuild)
         {

Code/Tools/ProjectManager/Platform/Linux/ProjectUtils_linux.cpp

@@ -17,13 +17,11 @@ namespace O3DE::ProjectManager
     namespace ProjectUtils
     {
         // The list of clang C/C++ compiler command lines to validate on the host Linux system
-        const QStringList SupportedClangCommands = {"clang-12|clang++-12"};
+        const QStringList SupportedClangVersions = {"13", "12", "11", "10", "9", "8", "7", "6.0"};
 
         AZ::Outcome<QProcessEnvironment, QString> GetCommandLineProcessEnvironment()
         {
             QProcessEnvironment currentEnvironment(QProcessEnvironment::systemEnvironment());
-            currentEnvironment.insert("CC", "clang-12");
-            currentEnvironment.insert("CXX", "clang++-12");
             return AZ::Success(currentEnvironment);
         }
 
@@ -39,16 +37,13 @@ namespace O3DE::ProjectManager
             }
 
             // Look for the first compatible version of clang. The list below will contain the known clang compilers that have been tested for O3DE.
-            for (const QString& supportClangCommand : SupportedClangCommands)
+            for (const QString& supportClangVersion : SupportedClangVersions)
             {
-                auto clangCompilers = supportClangCommand.split('|');
-                AZ_Assert(clangCompilers.length()==2, "Invalid clang compiler pair specification");
-
-                auto whichClangResult = ProjectUtils::ExecuteCommandResult("which", QStringList{clangCompilers[0]}, QProcessEnvironment::systemEnvironment());
-                auto whichClangPPResult = ProjectUtils::ExecuteCommandResult("which", QStringList{clangCompilers[1]}, QProcessEnvironment::systemEnvironment());
+                auto whichClangResult = ProjectUtils::ExecuteCommandResult("which", QStringList{QString("clang-%1").arg(supportClangVersion)}, QProcessEnvironment::systemEnvironment());
+                auto whichClangPPResult = ProjectUtils::ExecuteCommandResult("which", QStringList{QString("clang++-%1").arg(supportClangVersion)}, QProcessEnvironment::systemEnvironment());
                 if (whichClangResult.IsSuccess() && whichClangPPResult.IsSuccess())
                 {
-                    return AZ::Success(supportClangCommand);
+                    return AZ::Success(QString("clang-%1").arg(supportClangVersion));
                 }
             }
             return AZ::Failure(QObject::tr("Clang not found. <br><br>"

Templates/DefaultProject/Template/cmake/EngineFinder.cmake

@@ -13,8 +13,8 @@
 include_guard()
 
 # Read the engine name from the project_json file
-file(READ ${CMAKE_CURRENT_LIST_DIR}/project.json project_json)
-set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS ${CMAKE_CURRENT_LIST_DIR}/project.json)
+file(READ ${CMAKE_CURRENT_SOURCE_DIR}/project.json project_json)
+set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/project.json)
 
 string(JSON LY_ENGINE_NAME_TO_USE ERROR_VARIABLE json_error GET ${project_json} engine)
 if(json_error)

Templates/MinimalProject/Template/cmake/EngineFinder.cmake

@@ -13,8 +13,8 @@
 include_guard()
 
 # Read the engine name from the project_json file
-file(READ ${CMAKE_CURRENT_LIST_DIR}/project.json project_json)
-set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS ${CMAKE_CURRENT_LIST_DIR}/project.json)
+file(READ ${CMAKE_CURRENT_SOURCE_DIR}/project.json project_json)
+set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/project.json)
 
 string(JSON LY_ENGINE_NAME_TO_USE ERROR_VARIABLE json_error GET ${project_json} engine)
 if(json_error)