fcft: adapt to API changes in fcft-3.x

char32.c

@@ -0,0 +1,78 @@
+#include "char32.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include <wchar.h>
+
+#define LOG_MODULE "char32"
+#define LOG_ENABLE_DBG 0
+#include "log.h"
+
+/*
+ * For now, assume we can map directly to the corresponding wchar_t
+ * functions. This is true if:
+ *
+ *  - both data types have the same size
+ *  - both use the same encoding (though we require that encoding to be UTF-32)
+ */
+
+_Static_assert(
+    sizeof(wchar_t) == sizeof(char32_t), "wchar_t vs. char32_t size mismatch");
+
+#if !defined(__STDC_UTF_32__) || !__STDC_UTF_32__
+ #error "char32_t does not use UTF-32"
+#endif
+#if (!defined(__STDC_ISO_10646__) || !__STDC_ISO_10646__) && !defined(__FreeBSD__)
+ #error "wchar_t does not use UTF-32"
+#endif
+
+size_t
+c32len(const char32_t *s)
+{
+    return wcslen((const wchar_t *)s);
+}
+
+char32_t *
+ambstoc32(const char *src)
+{
+    if (src == NULL)
+        return NULL;
+
+    const size_t src_len = strlen(src);
+
+    char32_t *ret = malloc((src_len + 1) * sizeof(ret[0]));
+    if (ret == NULL)
+        return NULL;
+
+    mbstate_t ps = {0};
+    char32_t *out = ret;
+    const char *in = src;
+    const char *const end = src + src_len + 1;
+
+    size_t chars = 0;
+    size_t rc;
+
+    while ((rc = mbrtoc32(out, in, end - in, &ps)) != 0) {
+        switch (rc) {
+        case (size_t)-1:
+        case (size_t)-2:
+        case (size_t)-3:
+            goto err;
+        }
+
+        in += rc;
+        out++;
+        chars++;
+    }
+
+    *out = U'\0';
+
+    ret = realloc(ret, (chars + 1) * sizeof(ret[0]));
+    return ret;
+
+err:
+    free(ret);
+    return NULL;
+}