1 files changed, 54 insertions, 0 deletions
diff --git a/src/nvim/iconv.h b/src/nvim/iconv.h
new file mode 100644
index 0000000000..4ac0d3fdd4
--- /dev/null
+++ b/src/nvim/iconv.h
@@ -0,0 +1,54 @@
+#ifndef NVIM_ICONV_H
+#define NVIM_ICONV_H
+
+// iconv can be linked at compile-time as well as loaded at runtime. In the
+// latter case, some function pointers need to be initialized after loading
+// the library (see `iconv_enabled()` in mbyte.c). These function pointers
+// are stored in globals.h. Since globals.h includes iconv.h to get the
+// definition of USE_ICONV, we can't include it from iconv.h. One way to
+// solve this conundrum would be perhaps to let cmake decide the value of
+// USE_ICONV, or to put the USE_ICONV definition in config.h.in directly. As
+// it stands, globals.h needs to be included alongside iconv.h.
+
+#ifdef HAVE_CONFIG_H
+# include "auto/config.h"
+#endif
+
+// Use iconv() when it's available, either by linking to the library at
+// compile time or by loading it at runtime.
+#if (defined(HAVE_ICONV_H) && defined(HAVE_ICONV)) || defined(DYNAMIC_ICONV)
+# define USE_ICONV
+#endif
+
+// If we don't have the actual iconv header files present but USE_ICONV was
+// defined, we provide a type shim (pull in errno.h and define iconv_t).
+// This enables us to still load and use iconv dynamically at runtime.
+#ifdef USE_ICONV
+#  ifdef HAVE_ICONV_H
+#    include <iconv.h>
+#  else
+#    include <errno.h>
+typedef void *iconv_t;
+#  endif
+#endif
+
+// define some missing constants if necessary
+# ifdef USE_ICONV
+#  ifndef EILSEQ
+#   define EILSEQ 123
+#  endif
+#  ifdef DYNAMIC_ICONV
+// on win32 iconv.dll is dynamically loaded
+#   define ICONV_ERRNO (*iconv_errno())
+#   define ICONV_E2BIG  7
+#   define ICONV_EINVAL 22
+#   define ICONV_EILSEQ 42
+#  else
+#   define ICONV_ERRNO errno
+#   define ICONV_E2BIG  E2BIG
+#   define ICONV_EINVAL EINVAL
+#   define ICONV_EILSEQ EILSEQ
+#  endif
+# endif
+
+#endif  // NVIM_ICONV_H