file_util: Use an enum class for GetUserPath()

Instead of using an unsigned int as a parameter and expecting a user to
always pass in the correct values, we can just convert the enum into an
enum class and use that type as the parameter type instead, which makes
the interface more type safe.

We also get rid of the bookkeeping "NUM_" element in the enum by just
using an unordered map. This function is generally low-frequency in
terms of calls (and I'd hope so, considering otherwise would mean we're
slamming the disk with IO all the time) so I'd consider this acceptable
in this case.

3 files changed, 51 insertions, 50 deletions

diff --git a/src/common/common_paths.h b/src/common/common_paths.h
index 9bf3efaf2..6799a357a 100644
--- a/src/common/common_paths.h
+++ b/src/common/common_paths.h
@@ -26,7 +26,7 @@
 #define USA_DIR "USA"
 #define JAP_DIR "JAP"
 
-// Subdirs in the User dir returned by GetUserPath(D_USER_IDX)
+// Subdirs in the User dir returned by GetUserPath(UserPath::UserDir)
 #define CONFIG_DIR "config"
 #define CACHE_DIR "cache"
 #define SDMC_DIR "sdmc"
@@ -35,11 +35,11 @@
 #define LOG_DIR "log"
 
 // Filenames
-// Files in the directory returned by GetUserPath(D_CONFIG_IDX)
+// Files in the directory returned by GetUserPath(UserPath::ConfigDir)
 #define EMU_CONFIG "emu.ini"
 #define DEBUGGER_CONFIG "debugger.ini"
 #define LOGGER_CONFIG "logger.ini"
-// Files in the directory returned by GetUserPath(D_LOGS_IDX)
+// Files in the directory returned by GetUserPath(UserPath::LogDir)
 #define LOG_FILE "yuzu_log.txt"
 
 // Sys files
diff --git a/src/common/file_util.cpp b/src/common/file_util.cpp
index c882ab39f..1e28f7cbb 100644
--- a/src/common/file_util.cpp
+++ b/src/common/file_util.cpp
@@ -3,6 +3,7 @@
 // Refer to the license.txt file included.
 
 #include <sstream>
+#include <unordered_map>
 #include "common/assert.h"
 #include "common/common_funcs.h"
 #include "common/common_paths.h"
@@ -681,67 +682,68 @@ std::string GetSysDirectory() {
 
 // Returns a string with a yuzu data dir or file in the user's home
 // directory. To be used in "multi-user" mode (that is, installed).
-const std::string& GetUserPath(const unsigned int DirIDX, const std::string& newPath) {
-    static std::string paths[NUM_PATH_INDICES];
+const std::string& GetUserPath(UserPath path, const std::string& new_path) {
+    static std::unordered_map<UserPath, std::string> paths;
+    auto& user_path = paths[UserPath::UserDir];
 
     // Set up all paths and files on the first run
-    if (paths[D_USER_IDX].empty()) {
+    if (user_path.empty()) {
 #ifdef _WIN32
-        paths[D_USER_IDX] = GetExeDirectory() + DIR_SEP USERDATA_DIR DIR_SEP;
-        if (!FileUtil::IsDirectory(paths[D_USER_IDX])) {
-            paths[D_USER_IDX] = AppDataRoamingDirectory() + DIR_SEP EMU_DATA_DIR DIR_SEP;
+        user_path = GetExeDirectory() + DIR_SEP USERDATA_DIR DIR_SEP;
+        if (!FileUtil::IsDirectory(user_path)) {
+            user_path = AppDataRoamingDirectory() + DIR_SEP EMU_DATA_DIR DIR_SEP;
         } else {
             LOG_INFO(Common_Filesystem, "Using the local user directory");
         }
 
-        paths[D_CONFIG_IDX] = paths[D_USER_IDX] + CONFIG_DIR DIR_SEP;
-        paths[D_CACHE_IDX] = paths[D_USER_IDX] + CACHE_DIR DIR_SEP;
+        paths.emplace(UserPath::ConfigDir, user_path + CONFIG_DIR DIR_SEP);
+        paths.emplace(UserPath::CacheDir, user_path + CACHE_DIR DIR_SEP);
 #else
         if (FileUtil::Exists(ROOT_DIR DIR_SEP USERDATA_DIR)) {
-            paths[D_USER_IDX] = ROOT_DIR DIR_SEP USERDATA_DIR DIR_SEP;
-            paths[D_CONFIG_IDX] = paths[D_USER_IDX] + CONFIG_DIR DIR_SEP;
-            paths[D_CACHE_IDX] = paths[D_USER_IDX] + CACHE_DIR DIR_SEP;
+            user_path = ROOT_DIR DIR_SEP USERDATA_DIR DIR_SEP;
+            paths.emplace(UserPath::ConfigDir, user_path + CONFIG_DIR DIR_SEP);
+            paths.emplace(UserPath::CacheDir, user_path + CACHE_DIR DIR_SEP);
         } else {
             std::string data_dir = GetUserDirectory("XDG_DATA_HOME");
             std::string config_dir = GetUserDirectory("XDG_CONFIG_HOME");
             std::string cache_dir = GetUserDirectory("XDG_CACHE_HOME");
 
-            paths[D_USER_IDX] = data_dir + DIR_SEP EMU_DATA_DIR DIR_SEP;
-            paths[D_CONFIG_IDX] = config_dir + DIR_SEP EMU_DATA_DIR DIR_SEP;
-            paths[D_CACHE_IDX] = cache_dir + DIR_SEP EMU_DATA_DIR DIR_SEP;
+            user_path = data_dir + DIR_SEP EMU_DATA_DIR DIR_SEP;
+            paths.emplace(UserPath::ConfigDir, config_dir + DIR_SEP EMU_DATA_DIR DIR_SEP);
+            paths.emplace(UserPath::CacheDir, cache_dir + DIR_SEP EMU_DATA_DIR DIR_SEP);
         }
 #endif
-        paths[D_SDMC_IDX] = paths[D_USER_IDX] + SDMC_DIR DIR_SEP;
-        paths[D_NAND_IDX] = paths[D_USER_IDX] + NAND_DIR DIR_SEP;
-        paths[D_SYSDATA_IDX] = paths[D_USER_IDX] + SYSDATA_DIR DIR_SEP;
+        paths.emplace(UserPath::SDMCDir, user_path + SDMC_DIR DIR_SEP);
+        paths.emplace(UserPath::NANDDir, user_path + NAND_DIR DIR_SEP);
+        paths.emplace(UserPath::SysDataDir, user_path + SYSDATA_DIR DIR_SEP);
         // TODO: Put the logs in a better location for each OS
-        paths[D_LOGS_IDX] = paths[D_USER_IDX] + LOG_DIR DIR_SEP;
+        paths.emplace(UserPath::LogDir, user_path + LOG_DIR DIR_SEP);
     }
 
-    if (!newPath.empty()) {
-        if (!FileUtil::IsDirectory(newPath)) {
-            LOG_ERROR(Common_Filesystem, "Invalid path specified {}", newPath);
-            return paths[DirIDX];
+    if (!new_path.empty()) {
+        if (!FileUtil::IsDirectory(new_path)) {
+            LOG_ERROR(Common_Filesystem, "Invalid path specified {}", new_path);
+            return paths[path];
         } else {
-            paths[DirIDX] = newPath;
+            paths[path] = new_path;
         }
 
-        switch (DirIDX) {
-        case D_ROOT_IDX:
-            paths[D_USER_IDX] = paths[D_ROOT_IDX] + DIR_SEP;
+        switch (path) {
+        case UserPath::RootDir:
+            user_path = paths[UserPath::RootDir] + DIR_SEP;
             break;
 
-        case D_USER_IDX:
-            paths[D_USER_IDX] = paths[D_ROOT_IDX] + DIR_SEP;
-            paths[D_CONFIG_IDX] = paths[D_USER_IDX] + CONFIG_DIR DIR_SEP;
-            paths[D_CACHE_IDX] = paths[D_USER_IDX] + CACHE_DIR DIR_SEP;
-            paths[D_SDMC_IDX] = paths[D_USER_IDX] + SDMC_DIR DIR_SEP;
-            paths[D_NAND_IDX] = paths[D_USER_IDX] + NAND_DIR DIR_SEP;
+        case UserPath::UserDir:
+            user_path = paths[UserPath::RootDir] + DIR_SEP;
+            paths[UserPath::ConfigDir] = user_path + CONFIG_DIR DIR_SEP;
+            paths[UserPath::CacheDir] = user_path + CACHE_DIR DIR_SEP;
+            paths[UserPath::SDMCDir] = user_path + SDMC_DIR DIR_SEP;
+            paths[UserPath::NANDDir] = user_path + NAND_DIR DIR_SEP;
             break;
         }
     }
 
-    return paths[DirIDX];
+    return paths[path];
 }
 
 size_t WriteStringToFile(bool text_file, const std::string& str, const char* filename) {
diff --git a/src/common/file_util.h b/src/common/file_util.h
index 1f38b1560..ff01bf0ff 100644
--- a/src/common/file_util.h
+++ b/src/common/file_util.h
@@ -16,21 +16,20 @@
 #include "common/string_util.h"
 #endif
 
-// User directory indices for GetUserPath
-enum {
-    D_USER_IDX,
-    D_ROOT_IDX,
-    D_CONFIG_IDX,
-    D_CACHE_IDX,
-    D_SDMC_IDX,
-    D_NAND_IDX,
-    D_SYSDATA_IDX,
-    D_LOGS_IDX,
-    NUM_PATH_INDICES
-};
-
 namespace FileUtil {
 
+// User paths for GetUserPath
+enum class UserPath {
+    CacheDir,
+    ConfigDir,
+    LogDir,
+    NANDDir,
+    RootDir,
+    SDMCDir,
+    SysDataDir,
+    UserDir,
+};
+
 // FileSystem tree node/
 struct FSTEntry {
     bool isDirectory;
@@ -123,7 +122,7 @@ bool SetCurrentDir(const std::string& directory);
 
 // Returns a pointer to a string with a yuzu data dir in the user's home
 // directory. To be used in "multi-user" mode (that is, installed).
-const std::string& GetUserPath(const unsigned int DirIDX, const std::string& newPath = "");
+const std::string& GetUserPath(UserPath path, const std::string& new_path = "");
 
 // Returns the path to where the sys file are
 std::string GetSysDirectory();