MSVC: Fix an "incompatible pointer types" compiler warning

In particular, the following warning is issued while compiling
compat/msvc.c:

...mingw.c(223) : warning C4133: 'function' : incompatible \
types - from '_stati64 *' to '_stat64 *'

which relates to a call of _fstati64() in the mingw_fstat()
function definition.

This is caused by various layers of macro magic and attempts to
avoid macro redefinition compiler warnings. For example, the call
to _fstati64() mentioned above is actually a call to _fstat64(),
and expects a pointer to a struct _stat64 rather than the struct
_stati64 which is passed to mingw_fstat().

The definition of struct _stati64 given in compat/msvc.h had the
same "shape" as the definition of struct _stat64, so the call to
_fstat64() does not actually cause any runtime errors, but the
structure types are indeed incompatible.

In order to avoid the compiler warning, we add declarations for the
mingw_lstat() and mingw_fstat() functions and supporting macros to
msvc.h, suppressing the corresponding declarations in mingw.h, so
that we can use the appropriate structure type (and function) names
from the msvc headers.

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/compat/mingw.h b/compat/mingw.h
index a105dc9a271bdddc14b5de4c20cd94cc404a72d4..afe12ea55469f7a40e35edf8bcf8493e91e0980c 100644 (file)
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -209,13 +209,15 @@ int mingw_getpagesize(void);
  * mingw_fstat() instead of fstat() on Windows.
  */
 #define off_t off64_t
  * mingw_fstat() instead of fstat() on Windows.
  */
 #define off_t off64_t

-#define stat _stati64

 #define lseek _lseeki64
 #define lseek _lseeki64

+#ifndef ALREADY_DECLARED_STAT_FUNCS
+#define stat _stati64

 int mingw_lstat(const char *file_name, struct stat *buf);
 int mingw_fstat(int fd, struct stat *buf);
 #define fstat mingw_fstat
 #define lstat mingw_lstat
 #define _stati64(x,y) mingw_lstat(x,y)
 int mingw_lstat(const char *file_name, struct stat *buf);
 int mingw_fstat(int fd, struct stat *buf);
 #define fstat mingw_fstat
 #define lstat mingw_lstat
 #define _stati64(x,y) mingw_lstat(x,y)

+#endif

 
 int mingw_utime(const char *file_name, const struct utimbuf *times);
 #define utime mingw_utime
 
 int mingw_utime(const char *file_name, const struct utimbuf *times);
 #define utime mingw_utime

diff --git a/compat/msvc.h b/compat/msvc.h
index 9c753a560fcadb44a6e4afb22828584b6fd20db3..023aba0238c844f79f2662a4b885058acbfc91fd 100644 (file)
--- a/compat/msvc.h
+++ b/compat/msvc.h
@@ -21,30 +21,22 @@ static __inline int strcasecmp (const char *s1, const char *s2)
 }
 
 #undef ERROR
 }
 
 #undef ERROR

-#undef stat
-#undef _stati64
-#include "compat/mingw.h"
-#undef stat
-#define stat _stati64
+
+/* Use mingw_lstat() instead of lstat()/stat() and mingw_fstat() instead
+ * of fstat(). We add the declaration of these functions here, suppressing
+ * the corresponding declarations in mingw.h, so that we can use the
+ * appropriate structure type (and function) names from the msvc headers.
+ */
+#define stat _stat64
+int mingw_lstat(const char *file_name, struct stat *buf);
+int mingw_fstat(int fd, struct stat *buf);
+#define fstat mingw_fstat
+#define lstat mingw_lstat

 #define _stat64(x,y) mingw_lstat(x,y)
 #define _stat64(x,y) mingw_lstat(x,y)

+#define ALREADY_DECLARED_STAT_FUNCS
+
+#include "compat/mingw.h"
+
+#undef ALREADY_DECLARED_STAT_FUNCS

 
 

-/*
-   Even though _stati64 is normally just defined at _stat64
-   on Windows, we specify it here as a proper struct to avoid
-   compiler warnings about macro redefinition due to magic in
-   mingw.h. Struct taken from ReactOS (GNU GPL license).
-*/
-struct _stati64 {
-       _dev_t  st_dev;
-       _ino_t  st_ino;
-       unsigned short st_mode;
-       short   st_nlink;
-       short   st_uid;
-       short   st_gid;
-       _dev_t  st_rdev;
-       __int64 st_size;
-       time_t  st_atime;
-       time_t  st_mtime;
-       time_t  st_ctime;
-};

 #endif
 #endif