Files
git/compat/win32.h
Karsten Blees bc0f684bfe Win32: simplify loading of DLL functions
Dynamic loading of DLL functions is duplicated in several places.

Add a set of macros to simplify the process.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-10-13 14:26:35 +02:00

82 lines
2.0 KiB
C

#ifndef WIN32_H
#define WIN32_H
/* common Win32 functions for MinGW and Cygwin */
#ifndef GIT_WINDOWS_NATIVE /* Not defined for Cygwin */
#include <windows.h>
#endif
static inline int file_attr_to_st_mode (DWORD attr, DWORD tag)
{
int fMode = S_IREAD;
if ((attr & FILE_ATTRIBUTE_REPARSE_POINT) && tag == IO_REPARSE_TAG_SYMLINK)
fMode |= S_IFLNK;
else if (attr & FILE_ATTRIBUTE_DIRECTORY)
fMode |= S_IFDIR;
else
fMode |= S_IFREG;
if (!(attr & FILE_ATTRIBUTE_READONLY))
fMode |= S_IWRITE;
return fMode;
}
static inline int get_file_attr(const char *fname, WIN32_FILE_ATTRIBUTE_DATA *fdata)
{
if (GetFileAttributesExA(fname, GetFileExInfoStandard, fdata))
return 0;
switch (GetLastError()) {
case ERROR_ACCESS_DENIED:
case ERROR_SHARING_VIOLATION:
case ERROR_LOCK_VIOLATION:
case ERROR_SHARING_BUFFER_EXCEEDED:
return EACCES;
case ERROR_BUFFER_OVERFLOW:
return ENAMETOOLONG;
case ERROR_NOT_ENOUGH_MEMORY:
return ENOMEM;
default:
return ENOENT;
}
}
/* simplify loading of DLL functions */
struct proc_addr {
const char *const dll;
const char *const function;
FARPROC pfunction;
unsigned initialized : 1;
};
/* Declares a function to be loaded dynamically from a DLL. */
#define DECLARE_PROC_ADDR(dll, rettype, function, ...) \
static struct proc_addr proc_addr_##function = \
{ #dll, #function, NULL, 0 }; \
static rettype (WINAPI *function)(__VA_ARGS__)
/*
* Loads a function from a DLL (once-only).
* Returns non-NULL function pointer on success.
* Returns NULL + errno == ENOSYS on failure.
*/
#define INIT_PROC_ADDR(function) (function = get_proc_addr(&proc_addr_##function))
static inline void *get_proc_addr(struct proc_addr *proc)
{
/* only do this once */
if (!proc->initialized) {
HANDLE hnd;
proc->initialized = 1;
hnd = LoadLibraryA(proc->dll);
if (hnd)
proc->pfunction = GetProcAddress(hnd, proc->function);
}
/* set ENOSYS if DLL or function was not found */
if (!proc->pfunction)
errno = ENOSYS;
return proc->pfunction;
}
#endif