Windows: redirect standard I/O and convert text to UTF-16

Preprocessor magic is used to redirect putc/fputc/fputs/printf/fprintf
to custom implementations.

The custom implementations try to figure out if we are printing to the
console and, if so, convert the resulting strings to UTF-16 and print
them through ConsoleWriteW. If the output is redirected to a file or
a pipe, the original (presummed) UTF-8 is kept.

Simply setting the console output codepage to UTF-8 does not work,
because the standard I/O facilities of MSVCRT either does not support
unicode (in non-wchar mode), or has half-broken support through fputs,
which can still break up multi-byte sequences through its internal
buffering.

Likewise, changing the codepage and using ConsoleWriteA, or trying to
use fputws did not work in a test VM either.

This approach is the one that worked most consistently among the
ones tried, but also has problems. E.g. it breaks when setting the
codepage to UTF-8 manually (using `chcp 65001`).

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 14 insertions, 2 deletions

diff --git a/include/compat.h b/include/compat.h
index 59133c9..65872ec 100644
--- a/include/compat.h
+++ b/include/compat.h
@@ -8,9 +8,11 @@
 #define COMPAT_H
 
 #include "sqfs/predef.h"
+#include "fstream.h"
 #include "config.h"
 
 #include <limits.h>
+#include <stdio.h>
 
 #if defined(__GNUC__) && __GNUC__ >= 5
 #	define SZ_ADD_OV __builtin_add_overflow
@@ -228,9 +230,19 @@ int fnmatch(const char *, const char *, int);
 #endif
 
 #if defined(_WIN32) || defined(__WINDOWS__)
-#define main sqfs_tools_main
-
 extern int sqfs_tools_main(int argc, char **argv);
+
+int stfs_tools_fputc(int c, FILE *strm);
+int stfs_tools_fputs(const char *str, FILE *strm);
+int stfs_tools_printf(const char *fmt, ...) PRINTF_ATTRIB(1, 2);
+int stfs_tools_fprintf(FILE *strm, const char *fmt, ...) PRINTF_ATTRIB(2, 3);
+
+#define main sqfs_tools_main
+#define printf stfs_tools_printf
+#define fprintf stfs_tools_fprintf
+#define fputs stfs_tools_fputs
+#define fputc stfs_tools_fputc
+#define putc stfs_tools_fputc
 #endif
 
 #endif /* COMPAT_H */