Warning fixes/supressions

With this there are no more warnings when compiling with mingw and with
clang from android-ndk.

There are some remaining implicit declaration and int conversion
warnings in libretro-common when compiling using latest gcc on linux.
But maybe they should be first fixed first in the upstream
libretro-common so they are not reintroduced later on.

deps/libmad/frame.c

@@ -299,7 +299,7 @@ int mad_header_decode(struct mad_header *header, struct mad_stream *stream)
     if (!stream->sync)
       ptr = stream->this_frame;
 
-    if (end - ptr < stream->skiplen) {
+    if ((unsigned)(end - ptr) < stream->skiplen) {
       stream->skiplen   -= end - ptr;
       stream->next_frame = end;
 
@@ -384,7 +384,7 @@ int mad_header_decode(struct mad_header *header, struct mad_stream *stream)
   }
 
   /* verify there is enough data left in buffer to decode this frame */
-  if (N + MAD_BUFFER_GUARD > end - stream->this_frame) {
+  if (N + MAD_BUFFER_GUARD > (unsigned)(end - stream->this_frame)) {
     stream->next_frame = stream->this_frame;
 
     stream->error = MAD_ERROR_BUFLEN;

deps/libmad/layer3.c

@@ -880,7 +880,7 @@ mad_fixed_t III_requantize(unsigned int value, signed int exp)
   exp += power->exponent;
 
   if (exp < 0) {
-    if (-exp >= sizeof(mad_fixed_t) * CHAR_BIT) {
+    if (-exp >= (int)sizeof(mad_fixed_t) * CHAR_BIT) {
       /* underflow */
       requantized = 0;
     }
@@ -1035,7 +1035,7 @@ enum mad_error III_huffdecode(struct mad_bitptr *ptr, mad_fixed_t xr[576],
 	  break;
 
 	case 15:
-	  if (cachesz < linbits + 2) {
+	  if (cachesz < (int)linbits + 2) {
 	    bitcache   = (bitcache << 16) | mad_bit_read(&peek, 16);
 	    cachesz   += 16;
 	    bits_left -= 16;
@@ -1070,7 +1070,7 @@ enum mad_error III_huffdecode(struct mad_bitptr *ptr, mad_fixed_t xr[576],
 	  break;
 
 	case 15:
-	  if (cachesz < linbits + 1) {
+	  if (cachesz < (int)linbits + 1) {
 	    bitcache   = (bitcache << 16) | mad_bit_read(&peek, 16);
 	    cachesz   += 16;
 	    bits_left -= 16;

libretro/libretro.c

@@ -498,7 +498,7 @@ static void extract_directory(char *buf, const char *path, size_t size)
 static char* remove_extension(char *buf, const char *path, size_t size)
 {
   char *base;
-  strncpy(buf, path, size - 1);
+  memcpy(buf, path, size - 1);
   buf[size - 1] = '\0';
 
   base = strrchr(buf, '.');
@@ -515,7 +515,8 @@ static wadinfo_t get_wadinfo(const char *path)
    wadinfo_t header;
    if (fp != NULL)
    {
-      fread(&header, sizeof(header), 1, fp);
+      if(fread(&header, sizeof(header), 1, fp) != 1)
+         I_Error("get_wadinfo: error reading file header");
       fclose(fp);
    }
    else
@@ -542,7 +543,7 @@ bool retro_load_game(const struct retro_game_info *info)
       wadinfo_t header;
       char *deh, *extension, *baseconfig;
 
-      char name_without_ext[4096];
+      char name_without_ext[1023];
       bool use_external_savedir = false;
       const char *base_save_dir = NULL;
 
@@ -559,7 +560,8 @@ bool retro_load_game(const struct retro_game_info *info)
       else
       {
         header = get_wadinfo(info->path);
-        if(header.identification == NULL)
+        // header.identification is static array, always non-NULL, but it might be empty if it couldn't be read
+        if(header.identification[0] == 0)
         {
           I_Error("retro_load_game: couldn't read WAD header from '%s'", info->path);
           goto failed;
@@ -574,9 +576,8 @@ bool retro_load_game(const struct retro_game_info *info)
           argv[argc++] = strdup("-file");
           argv[argc++] = strdup(info->path);
         }
-        else
-        {
-          I_Error("retro_load_game: invalid WAD header '%s'", header.identification);
+        else {
+          I_Error("retro_load_game: invalid WAD header '%.*s'", 4, header.identification);
           goto failed;
         }
 

libretro/libretro_sound.c

@@ -143,7 +143,8 @@ static void* I_SndLoadSample (const char* sfxname, int* len)
 {
     int i, x, padded_sfx_len, sfxlump_num, sfxlump_len;
     char sfxlump_name[20];
-    uint8_t *sfxlump_data, *sfxlump_sound, *padded_sfx_data;
+    const uint8_t *sfxlump_data, *sfxlump_sound;
+    uint8_t *padded_sfx_data;
     uint16_t orig_rate;
     float times;
 
@@ -185,7 +186,7 @@ static void* I_SndLoadSample (const char* sfxname, int* len)
             padded_sfx_data[i] = 128; // fill the rest with silence
     }
 
-    Z_Free (sfxlump_data); //  free original lump
+    Z_Free ((void*) sfxlump_data); //  free original lump
 
     *len = padded_sfx_len;
     return (void *)(padded_sfx_data);
@@ -619,7 +620,7 @@ int I_RegisterSong(const void* data, size_t len)
     {
       music_handle = music_players[i]->registersong(data, len);
       if (music_handle) {
-        current_player = music_players[i];
+        current_player = (music_player_t*)music_players[i];
         break;
       }
     }
@@ -673,7 +674,7 @@ int I_RegisterSong(const void* data, size_t len)
       mem_get_buf(outstream, &outbuf, &outbuf_len);
       music_handle = opl_synth_player.registersong(outbuf, outbuf_len);
       if(music_handle)
-        current_player = &opl_synth_player;
+        current_player = (music_player_t*)&opl_synth_player;
     }
 
     mem_fclose(instream);

src/am_map.c

@@ -596,7 +596,7 @@ static void AM_maxOutWindowScale(void)
 boolean AM_Responder
 ( event_t*  ev )
 {
-   static int cheatstate=0;
+   //static int cheatstate=0;
    static int bigstate=0;
    int ch;                                                       // phares
    int rc = FALSE;
@@ -694,7 +694,7 @@ boolean AM_Responder
       }
       else                                                        // phares
       {
-         cheatstate=0;
+         //cheatstate=0;
          rc = FALSE;
       }
    }