Merge other top-level C code

Change-Id: I0ff77f51595599cc3de5183c6c655fd261e3d925

args.c

@@ -52,7 +52,7 @@ int arg_match(struct arg *arg_, const struct arg_def *def, char **argv) {
     arg.val = def->has_val ? arg.argv[1] : NULL;
     arg.argv_step = def->has_val ? 2 : 1;
   } else if (def->long_name) {
-    int name_len = strlen(def->long_name);
+    const size_t name_len = strlen(def->long_name);
 
     if (strlen(arg.argv[0]) >= name_len + 2
         && arg.argv[0][1] == '-'

tools_common.c

@@ -9,14 +9,20 @@
  */
 #include <stdio.h>
 #include "tools_common.h"
-#ifdef _WIN32
+#if defined(_WIN32) || defined(__OS2__)
 #include <io.h>
 #include <fcntl.h>
+
+#ifdef __OS2__
+#define _setmode    setmode
+#define _fileno     fileno
+#define _O_BINARY   O_BINARY
+#endif
 #endif
 
 FILE *set_binary_mode(FILE *stream) {
   (void)stream;
-#ifdef _WIN32
+#if defined(_WIN32) || defined(__OS2__)
   _setmode(_fileno(stream), _O_BINARY);
 #endif
   return stream;

y4minput.c

@@ -669,7 +669,7 @@ int y4m_input_open(y4m_input *_y4m, FILE *_fin, char *_skip, int _nskip) {
       buffer[i] = *_skip++;
       _nskip--;
     } else {
-      ret = fread(buffer + i, 1, 1, _fin);
+      ret = (int)fread(buffer + i, 1, 1, _fin);
       if (ret < 1)return -1;
     }
     if (buffer[i] == '\n')break;
@@ -815,7 +815,7 @@ int y4m_input_fetch_frame(y4m_input *_y4m, FILE *_fin, vpx_image_t *_img) {
   int  c_sz;
   int  ret;
   /*Read and skip the frame header.*/
-  ret = fread(frame, 1, 6, _fin);
+  ret = (int)fread(frame, 1, 6, _fin);
   if (ret < 6)return 0;
   if (memcmp(frame, "FRAME", 5)) {
     fprintf(stderr, "Loss of framing in Y4M input data\n");