Move common test functions to separate module

This resolves warnings for missing function prototypes.

test/tests.c

@@ -0,0 +1,46 @@
+/* Common functions for our test programs. */
+
+#include "tests.h"
+
+size_t lineno = 0;
+
+void check(int cond, const char *format, ...)
+{
+     if (!cond) {
+          va_list args;
+          fprintf(stderr, "line %zd: ", lineno);
+          va_start(args, format);
+          vfprintf(stderr, format, args);
+          va_end(args);
+          fprintf(stderr, "\n");
+          exit(1);
+     }
+}
+
+size_t skipspaces(const char *buf, size_t i)
+{
+    while (isspace(buf[i])) ++i;
+    return i;
+}
+
+/* if buf points to a sequence of codepoints encoded as hexadecimal strings,
+   separated by whitespace, and terminated by any character not in
+   [0-9a-fA-F] or whitespace, then stores the corresponding utf8 string
+   in dest, returning the number of bytes read from buf */
+size_t encode(char *dest, const char *buf)
+{
+     size_t i = 0, j, d = 0;
+     for (;;) {
+          int c;
+          i = skipspaces(buf, i);
+          for (j=i; buf[j] && strchr("0123456789abcdef", tolower(buf[j])); ++j)
+               ; /* find end of hex input */
+          if (j == i) { /* no codepoint found */
+               dest[d] = 0; /* NUL-terminate destination string */
+               return i + 1;
+          }
+          check(sscanf(buf + i, "%x", (unsigned int *)&c) == 1, "invalid hex input %s", buf+i);
+          i = j; /* skip to char after hex input */
+          d += utf8proc_encode_char(c, (utf8proc_uint8_t *) (dest + d));
+     }
+}

test/tests.h

@@ -8,46 +8,8 @@
 
 #include "../utf8proc.h"
 
-size_t lineno = 0;
-
-void check(int cond, const char *format, ...)
-{
-     if (!cond) {
-          va_list args;
-          fprintf(stderr, "line %zd: ", lineno);
-          va_start(args, format);
-          vfprintf(stderr, format, args);
-          va_end(args);
-          fprintf(stderr, "\n");
-          exit(1);
-     }
-}
-
-size_t skipspaces(const char *buf, size_t i)
-{
-    while (isspace(buf[i])) ++i;
-    return i;
-}
-
-/* if buf points to a sequence of codepoints encoded as hexadecimal strings,
-   separated by whitespace, and terminated by any character not in
-   [0-9a-fA-F] or whitespace, then stores the corresponding utf8 string
-   in dest, returning the number of bytes read from buf */
-size_t encode(char *dest, const char *buf)
-{
-     size_t i = 0, j, d = 0;
-     for (;;) {
-          int c;
-          i = skipspaces(buf, i);
-          for (j=i; buf[j] && strchr("0123456789abcdef", tolower(buf[j])); ++j)
-               ; /* find end of hex input */
-          if (j == i) { /* no codepoint found */
-               dest[d] = 0; /* NUL-terminate destination string */
-               return i + 1;
-          }
-          check(sscanf(buf + i, "%x", (unsigned int *)&c) == 1, "invalid hex input %s", buf+i);
-          i = j; /* skip to char after hex input */
-          d += utf8proc_encode_char(c, (utf8proc_uint8_t *) (dest + d));
-     }
-}
+extern size_t lineno;
 
+void check(int cond, const char *format, ...);
+size_t skipspaces(const char *buf, size_t i);
+size_t encode(char *dest, const char *buf);