yuzu_cmd: Allow user to specify config file location

Adds an option `-c` or `--config` with one required argument that allows
the user to specify to where the config file is located. Useful for
scripts that run specific games with different preferences for settings.

src/yuzu_cmd/config.cpp

@@ -3,6 +3,7 @@
 // Refer to the license.txt file included.
 
 #include <memory>
+#include <optional>
 #include <sstream>
 
 // Ignore -Wimplicit-fallthrough due to https://github.com/libsdl-org/SDL/issues/4307
@@ -29,11 +30,12 @@
 
 namespace FS = Common::FS;
 
-Config::Config() {
+const std::filesystem::path default_config_path =
-    // TODO: Don't hardcode the path; let the frontend decide where to put the config files.
+    FS::GetYuzuPath(FS::YuzuPath::ConfigDir) / "sdl2-config.ini";
-    sdl2_config_loc = FS::GetYuzuPath(FS::YuzuPath::ConfigDir) / "sdl2-config.ini";
-    sdl2_config = std::make_unique<INIReader>(FS::PathToUTF8String(sdl2_config_loc));
 
+Config::Config(std::optional<std::filesystem::path> config_path)
+    : sdl2_config_loc{config_path.value_or(default_config_path)},
+      sdl2_config{std::make_unique<INIReader>(FS::PathToUTF8String(sdl2_config_loc))} {
     Reload();
 }
 

src/yuzu_cmd/config.h

@@ -6,6 +6,7 @@
 
 #include <filesystem>
 #include <memory>
+#include <optional>
 #include <string>
 
 #include "common/settings.h"
@@ -13,14 +14,14 @@
 class INIReader;
 
 class Config {
-    std::unique_ptr<INIReader> sdl2_config;
     std::filesystem::path sdl2_config_loc;
+    std::unique_ptr<INIReader> sdl2_config;
 
     bool LoadINI(const std::string& default_contents = "", bool retry = true);
     void ReadValues();
 
 public:
-    Config();
+    explicit Config(std::optional<std::filesystem::path> config_path);
     ~Config();
 
     void Reload();

src/yuzu_cmd/yuzu.cpp

@@ -66,7 +66,8 @@ static void PrintHelp(const char* argv0) {
                  "-f, --fullscreen      Start in fullscreen mode\n"
                  "-h, --help            Display this help and exit\n"
                  "-v, --version         Output version information and exit\n"
-                 "-p, --program         Pass following string as arguments to executable\n";
+                 "-p, --program         Pass following string as arguments to executable\n"
+                 "-c, --config          Load the specified configuration file\n";
 }
 
 static void PrintVersion() {
@@ -78,7 +79,6 @@ int main(int argc, char** argv) {
     Common::Log::Initialize();
     Common::Log::SetColorConsoleBackendEnabled(true);
     Common::DetachedTasks detached_tasks;
-    Config config;
 
     int option_index = 0;
 #ifdef _WIN32
@@ -91,19 +91,24 @@ int main(int argc, char** argv) {
     }
 #endif
     std::string filepath;
+    std::optional<std::string> config_path;
+    std::string program_args;
 
     bool fullscreen = false;
 
     static struct option long_options[] = {
+        // clang-format off
         {"fullscreen", no_argument, 0, 'f'},
         {"help", no_argument, 0, 'h'},
         {"version", no_argument, 0, 'v'},
         {"program", optional_argument, 0, 'p'},
+        {"config", required_argument, 0, 'c'},
         {0, 0, 0, 0},
+        // clang-format on
     };
 
     while (optind < argc) {
-        int arg = getopt_long(argc, argv, "g:fhvp::", long_options, &option_index);
+        int arg = getopt_long(argc, argv, "g:fhvp::c:", long_options, &option_index);
         if (arg != -1) {
             switch (static_cast<char>(arg)) {
             case 'f':
@@ -117,9 +122,12 @@ int main(int argc, char** argv) {
                 PrintVersion();
                 return 0;
             case 'p':
-                Settings::values.program_args = argv[optind];
+                program_args = argv[optind];
                 ++optind;
                 break;
+            case 'c':
+                config_path = optarg;
+                break;
             }
         } else {
 #ifdef _WIN32
@@ -131,6 +139,12 @@ int main(int argc, char** argv) {
         }
     }
 
+    Config config{config_path};
+
+    if (!program_args.empty()) {
+        Settings::values.program_args = program_args;
+    }
+
 #ifdef _WIN32
     LocalFree(argv_w);
 #endif