(svn r1805) Teach the driver layer a few things about const correctness

dedicated.c

@@ -128,7 +128,8 @@ void CloseWindowsConsoleThread(void)
 
 #endif
 
-static const char *DedicatedVideoStart(char **parm) {
+static const char *DedicatedVideoStart(const char * const *parm)
+{
 	_screen.width = _screen.pitch = _cur_resolution[0];
 	_screen.height = _cur_resolution[1];
 	_dedicated_video_mem = malloc(_cur_resolution[0]*_cur_resolution[1]);
@@ -306,7 +307,8 @@ const HalVideoDriver _dedicated_video_driver = {
 
 static void *_dedicated_video_mem;
 
-static const char *DedicatedVideoStart(char **parm) {
+static const char *DedicatedVideoStart(const char **parm)
+{
 	DEBUG(misc,0)("OpenTTD compiled without network-support, quiting...");
 
 	return NULL;

extmidi.c

@@ -26,7 +26,7 @@ static void extmidi_kill(void)
 	_pid = 0;
 }
 
-static char *extmidi_start(char **parm)
+static const char *extmidi_start(const char * const *parm)
 {
 	_pid = 0;
 	return NULL;

hal.h

@@ -2,12 +2,12 @@
 #define HAL_H
 
 typedef struct {
-	char *(*start)(char **parm);
+	const char *(*start)(const char * const *parm);
 	void (*stop)(void);
 } HalCommonDriver;
 
 typedef struct {
-	const char *(*start)(char **parm);
+	const char *(*start)(const char * const *parm);
 	void (*stop)(void);
 	void (*make_dirty)(int left, int top, int width, int height);
 	int (*main_loop)(void);
@@ -20,12 +20,12 @@ enum {
 };
 
 typedef struct {
-	char *(*start)(char **parm);
+	const char *(*start)(const char * const *parm);
 	void (*stop)(void);
 } HalSoundDriver;
 
 typedef struct {
-	char *(*start)(char **parm);
+	const char *(*start)(const char * const *parm);
 	void (*stop)(void);
 
 	void (*play_song)(const char *filename);
@@ -88,9 +88,9 @@ extern bool _dbg_screen_rect;
 
 void LoadDriver(int driver, const char *name);
 
-char *GetDriverParam(char **parm, const char *name);
-bool GetDriverParamBool(char **parm, const char *name);
-int GetDriverParamInt(char **parm, const char *name, int def);
+const char *GetDriverParam(const char * const *parm, const char *name);
+bool GetDriverParamBool(const char * const *parm, const char *name);
+int GetDriverParamInt(const char * const *parm, const char *name, int def);
 
 
 

os/beos/bemidi.cpp

@@ -9,7 +9,7 @@
 
 BMidiSynthFile midiSynthFile;
 
-static char *bemidi_start(char **parm)
+static const char *bemidi_start(const char * const *parm)
 {
 	return NULL;
 }

os2.c

@@ -656,7 +656,7 @@ static bool OS2MidiIsSongPlaying()
 	return strcmp(buf, "playing") == 0 || strcmp(buf, "seeking") == 0;
 }
 
-static char *OS2MidiStart(char **parm)
+static const char *OS2MidiStart(const char * const *parm)
 {
 	return 0;
 }

sdl.c

@@ -103,7 +103,7 @@ static const char sdl_files[] =
 
 static SDLProcs _proc;
 
-static char *LoadSdlDLL(void)
+static const char *LoadSdlDLL(void)
 {
 	if (_proc.SDL_Init != NULL)
 		return NULL;
@@ -138,11 +138,11 @@ static void SdlAbort(int sig)
 #endif
 
 
-static char *SdlOpen(uint32 x)
+static const char *SdlOpen(uint32 x)
 {
 #if defined(DYNAMICALLY_LOADED_SDL) && defined(WIN32)
 	{
-		char *s = LoadSdlDLL();
+		const char *s = LoadSdlDLL();
 		if (s != NULL) return s;
 	}
 #endif
@@ -540,7 +540,7 @@ static int PollEvent(void)
 	return -1;
 }
 
-static const char *SdlVideoStart(char **parm)
+static const char *SdlVideoStart(const char * const *parm)
 {
 	char buf[30];
 
@@ -654,11 +654,11 @@ static void CDECL fill_sound_buffer(void *userdata, Uint8 *stream, int len)
 	MxMixSamples(_mixer, stream, len / 4);
 }
 
-static char *SdlSoundStart(char **parm)
+static const char *SdlSoundStart(const char * const *parm)
 {
 	SDL_AudioSpec spec;
 
-	char *s = SdlOpen(SDL_INIT_AUDIO);
+	const char *s = SdlOpen(SDL_INIT_AUDIO);
 	if (s != NULL) return s;
 
 	spec.freq = GetDriverParamInt(parm, "hz", 11025);

ttd.c

@@ -100,7 +100,7 @@ char * CDECL str_fmt(const char *str, ...)
 
 
 // NULL midi driver
-static char *NullMidiStart(char **parm) { return NULL; }
+static const char *NullMidiStart(const char * const *parm) { return NULL; }
 static void NullMidiStop(void) {}
 static void NullMidiPlaySong(const char *filename) {}
 static void NullMidiStopSong(void) {}
@@ -118,7 +118,8 @@ const HalMusicDriver _null_music_driver = {
 
 // NULL video driver
 static void *_null_video_mem;
-static const char *NullVideoStart(char **parm) {
+static const char *NullVideoStart(const char * const *parm)
+{
 	_screen.width = _screen.pitch = _cur_resolution[0];
 	_screen.height = _cur_resolution[1];
 	_null_video_mem = malloc(_cur_resolution[0]*_cur_resolution[1]);
@@ -149,7 +150,7 @@ const HalVideoDriver _null_video_driver = {
 };
 
 // NULL sound driver
-static char *NullSoundStart(char **parm) { return NULL; }
+static const char *NullSoundStart(const char * const *parm) { return NULL; }
 static void NullSoundStop(void) {}
 const HalSoundDriver _null_sound_driver = {
 	NullSoundStart,
@@ -254,7 +255,7 @@ void LoadDriver(int driver, const char *name)
 	const char *err;
 	char *parm;
 	char buffer[256];
-	char *parms[32];
+	const char *parms[32];
 
 	parms[0] = NULL;
 
@@ -330,9 +331,9 @@ static void showhelp(void)
 }
 
 
-char *GetDriverParam(char **parm, const char *name)
+const char *GetDriverParam(const char * const *parm, const char *name)
 {
-	char *p;
+	const char *p;
 	int len = strlen(name);
 	while ((p = *parm++) != NULL) {
 		if (!strncmp(p,name,len)) {
@@ -343,15 +344,15 @@ char *GetDriverParam(char **parm, const char *name)
 	return NULL;
 }
 
-bool GetDriverParamBool(char **parm, const char *name)
+bool GetDriverParamBool(const char * const *parm, const char *name)
 {
-	char *p = GetDriverParam(parm, name);
+	const char *p = GetDriverParam(parm, name);
 	return p != NULL;
 }
 
-int GetDriverParamInt(char **parm, const char *name, int def)
+int GetDriverParamInt(const char * const *parm, const char *name, int def)
 {
-	char *p = GetDriverParam(parm, name);
+	const char *p = GetDriverParam(parm, name);
 	return p != NULL ? atoi(p) : def;
 }
 

w32dm.c

@@ -32,7 +32,7 @@
 #include "sound.h"
 #include "hal.h"
 
-static char * DMusicMidiStart(char **parm);
+static const char * DMusicMidiStart(const char * const *parm);
 static void DMusicMidiStop(void);
 static void DMusicMidiPlaySong(const char *filename);
 static void DMusicMidiStopSong(void);
@@ -60,7 +60,7 @@ extern void SetVolume (long);
 
 bool seeking = false;
 
-static char * DMusicMidiStart(char **parm)
+static const char * DMusicMidiStart(const char * const *parm)
 {
 	if (InitDirectMusic() == true)
 		return(0);

win32.c

@@ -606,7 +606,7 @@ static void FindResolutions(void)
 }
 
 
-static const char *Win32GdiStart(char **parm)
+static const char *Win32GdiStart(const char * const *parm)
 {
 	memset(&_wnd, 0, sizeof(_wnd));
 	_wnd.cursor_visible = true;
@@ -879,7 +879,7 @@ static DWORD WINAPI MidiThread(LPVOID arg)
 	return 0;
 }
 
-static char *Win32MidiStart(char **parm)
+static const char *Win32MidiStart(const char * const *parm)
 {
 	DWORD threadId;
 	memset(&_midi, 0, sizeof(_midi));
@@ -939,7 +939,7 @@ static void CALLBACK waveOutProc(HWAVEOUT hwo, UINT uMsg, DWORD dwInstance, DWOR
 	}
 }
 
-static char *Win32SoundStart(char **parm)
+static const char *Win32SoundStart(const char * const *parm)
 {
 	WAVEFORMATEX wfex;
 	int hz;