6 files changed, 40 insertions, 27 deletions

diff --git a/src/frontend/qt_sdl/Platform.cpp b/src/frontend/qt_sdl/Platform.cpp
index 6b48335..f626c88 100644
--- a/src/frontend/qt_sdl/Platform.cpp
+++ b/src/frontend/qt_sdl/Platform.cpp
@@ -288,7 +288,7 @@ bool GetConfigArray(ConfigEntry entry, void* data)
 }
 
 
-FILE* OpenFile(std::string path, std::string mode, bool mustexist)
+FILE* OpenFile(const std::string& path, const std::string& mode, bool mustexist)
 {
     QFile f(QString::fromStdString(path));
 
@@ -322,7 +322,7 @@ FILE* OpenFile(std::string path, std::string mode, bool mustexist)
     return file;
 }
 
-FILE* OpenLocalFile(std::string path, std::string mode)
+FILE* OpenLocalFile(const std::string& path, const std::string& mode)
 {
     QString qpath = QString::fromStdString(path);
 	QDir dir(qpath);
diff --git a/src/frontend/qt_sdl/ROMManager.cpp b/src/frontend/qt_sdl/ROMManager.cpp
index ac525b7..cb671e2 100644
--- a/src/frontend/qt_sdl/ROMManager.cpp
+++ b/src/frontend/qt_sdl/ROMManager.cpp
@@ -58,7 +58,7 @@ ARCodeFile* CheatFile = nullptr;
 bool CheatsOn = false;
 
 
-int LastSep(std::string path)
+int LastSep(const std::string& path)
 {
     int i = path.length() - 1;
     while (i >= 0)
@@ -72,32 +72,45 @@ int LastSep(std::string path)
     return -1;
 }
 
-std::string GetAssetPath(bool gba, std::string configpath, std::string ext, std::string file="")
+std::string GetAssetPath(bool gba, const std::string& configpath, const std::string& ext, const std::string& file = "")
 {
-    if (configpath.empty())
-        configpath = gba ? BaseGBAROMDir : BaseROMDir;
+    std::string result;
 
-    if (file.empty())
-    {
-        file = gba ? BaseGBAAssetName : BaseAssetName;
-        if (file.empty())
-            file = "firmware";
-    }
+    if (configpath.empty())
+        result = gba ? BaseGBAROMDir : BaseROMDir;
+    else
+        result = configpath;
 
+    // cut off trailing slashes
     for (;;)
     {
-        int i = configpath.length() - 1;
+        int i = result.length() - 1;
         if (i < 0) break;
-        if (configpath[i] == '/' || configpath[i] == '\\')
-            configpath = configpath.substr(0, i);
+        if (result[i] == '/' || result[i] == '\\')
+            result.resize(i);
         else
             break;
     }
 
-    if (!configpath.empty())
-        configpath += "/";
+    if (!result.empty())
+        result += '/';
+
+    if (file.empty())
+    {
+        std::string& baseName = gba ? BaseGBAAssetName : BaseAssetName;
+        if (baseName.empty())
+            result += "firmware";
+        else
+            result += baseName;
+    }
+    else
+    {
+        result += file;
+    }
+
+    result += ext;
 
-    return configpath + file + ext;
+    return result;
 }
 
 
@@ -288,7 +301,7 @@ bool SavestateExists(int slot)
     return Platform::FileExists(ssfile);
 }
 
-bool LoadState(std::string filename)
+bool LoadState(const std::string& filename)
 {
     // backup
     Savestate* backup = new Savestate("timewarp.mln", true);
@@ -335,7 +348,7 @@ bool LoadState(std::string filename)
     return true;
 }
 
-bool SaveState(std::string filename)
+bool SaveState(const std::string& filename)
 {
     Savestate* state = new Savestate(filename, true);
     if (state->Error)
diff --git a/src/frontend/qt_sdl/ROMManager.h b/src/frontend/qt_sdl/ROMManager.h
index 9e82a5b..efaed36 100644
--- a/src/frontend/qt_sdl/ROMManager.h
+++ b/src/frontend/qt_sdl/ROMManager.h
@@ -49,8 +49,8 @@ QString GBACartLabel();
 
 std::string GetSavestateName(int slot);
 bool SavestateExists(int slot);
-bool LoadState(std::string filename);
-bool SaveState(std::string filename);
+bool LoadState(const std::string& filename);
+bool SaveState(const std::string& filename);
 void UndoStateLoad();
 
 void EnableCheats(bool enable);
diff --git a/src/frontend/qt_sdl/SaveManager.cpp b/src/frontend/qt_sdl/SaveManager.cpp
index 31d2a68..005219b 100644
--- a/src/frontend/qt_sdl/SaveManager.cpp
+++ b/src/frontend/qt_sdl/SaveManager.cpp
@@ -25,7 +25,7 @@
 using Platform::Log;
 using Platform::LogLevel;
 
-SaveManager::SaveManager(std::string path) : QThread()
+SaveManager::SaveManager(const std::string& path) : QThread()
 {
     SecondaryBuffer = nullptr;
     SecondaryBufferLength = 0;
@@ -71,7 +71,7 @@ std::string SaveManager::GetPath()
     return Path;
 }
 
-void SaveManager::SetPath(std::string path, bool reload)
+void SaveManager::SetPath(const std::string& path, bool reload)
 {
     Path = path;
 
diff --git a/src/frontend/qt_sdl/SaveManager.h b/src/frontend/qt_sdl/SaveManager.h
index 0d38f4b..33035ed 100644
--- a/src/frontend/qt_sdl/SaveManager.h
+++ b/src/frontend/qt_sdl/SaveManager.h
@@ -34,11 +34,11 @@ class SaveManager : public QThread
     void run() override;
 
 public:
-    SaveManager(std::string path);
+    SaveManager(const std::string& path);
     ~SaveManager();
 
     std::string GetPath();
-    void SetPath(std::string path, bool reload);
+    void SetPath(const std::string& path, bool reload);
 
     void RequestFlush(const u8* savedata, u32 savelen, u32 writeoffset, u32 writelen);
     void CheckFlush();
diff --git a/src/frontend/qt_sdl/main.cpp b/src/frontend/qt_sdl/main.cpp
index 7015c6d..518d5f5 100644
--- a/src/frontend/qt_sdl/main.cpp
+++ b/src/frontend/qt_sdl/main.cpp
@@ -279,7 +279,7 @@ void micClose()
     micDevice = 0;
 }
 
-void micLoadWav(std::string name)
+void micLoadWav(const std::string& name)
 {
     SDL_AudioSpec format;
     memset(&format, 0, sizeof(SDL_AudioSpec));