file.c: handle long pathnames on Windows

Windows supports pathnames up to 32767 UTF-16 characters, but using
the standard interfaces only up to 260 characters. Wrap the functions
that take filenames on Windows.

Clean up the compatiblity layers some more for reduced #ifdefs.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
This commit is contained in:
H. Peter Anvin (Intel) 2019-05-15 13:07:21 -07:00
parent a7afe276da
commit 471120f485
3 changed files with 298 additions and 104 deletions

View File

@ -137,7 +137,6 @@ AC_CHECK_FUNCS([_fseeki64])
AC_CHECK_FUNCS([ftruncate _chsize _chsize_s])
AC_CHECK_FUNCS([fileno _fileno])
AC_CHECK_FUNCS(_filelengthi64)
AC_FUNC_MMAP
AC_CHECK_FUNCS(getpagesize)
AC_CHECK_FUNCS(sysconf)
@ -165,6 +164,7 @@ AC_CHECK_TYPES([struct _stati64])
AC_CHECK_TYPES([struct stat])
AC_CHECK_FUNCS([stat _stati64])
AC_CHECK_FUNCS([fstat _fstati64])
AC_CHECK_FUNCS([S_ISREG])
dnl Check for functions that might not be declared in the headers for
dnl various idiotic reasons (mostly because of library authors

View File

@ -78,15 +78,17 @@ void fwritezero(off_t bytes, FILE *fp)
{
size_t blksize;
#ifdef nasm_ftruncate
#ifdef os_ftruncate
if (bytes >= BUFSIZ && !ferror(fp) && !feof(fp)) {
off_t pos = ftello(fp);
if (pos >= 0) {
pos += bytes;
if (!fflush(fp) &&
!nasm_ftruncate(fileno(fp), pos) &&
!fseeko(fp, pos, SEEK_SET))
return;
if (pos != (off_t)-1) {
off_t end = pos + bytes;
if (!fflush(fp) && !os_ftruncate(fileno(fp), end)) {
fseeko(fp, 0, SEEK_END);
pos = ftello(fp);
if (pos != (off_t)-1)
bytes = end - pos; /* This SHOULD be zero */
}
}
}
#endif
@ -99,24 +101,89 @@ void fwritezero(off_t bytes, FILE *fp)
}
}
#ifdef _WIN32
/*
* On Windows, we want to use _wfopen(), as fopen() has a much smaller limit
* on the path length that it supports. Furthermore, we want to prefix the
* path name with \\?\ in order to let the Windows kernel know that
* we are not limited to PATH_MAX characters.
*/
os_filename os_mangle_filename(const char *filename)
{
mbstate_t ps;
size_t wclen;
wchar_t *buf;
const char *p;
/* If the filename is already prefixed with \\?\, don't add it again */
if ((filename[0] == '\\' || filename[0] == '/') &&
(filename[1] == '\\' || filename[1] == '/') &&
filename[2] == '?' &&
(filename[3] == '\\' || filename[3] == '/'))
filename += 4;
/*
* Note: mbsrtowcs() return (size_t)-1 on error, otherwise
* the length of the string *without* final NUL in wchar_t
* units. Thus we add 1 for the final NUL; the error value
* now becomes 0.
*/
memset(&ps, 0, sizeof ps); /* Begin in the initial state */
p = filename;
wclen = mbsrtowcs(NULL, &p, 0, &ps) + 1;
if (!wclen)
return NULL;
buf = nasm_malloc((wclen+4) * sizeof(wchar_t));
memcpy(buf, L"\\\\?\\", 4*sizeof(wchar_t));
memset(&ps, 0, sizeof ps); /* Begin in the initial state */
p = filename;
if (mbsrtowcs(buf+4, &p, wclen, &ps) + 1 != wclen || p) {
nasm_free(buf);
return NULL;
}
return buf;
}
#endif
FILE *nasm_open_read(const char *filename, enum file_flags flags)
{
FILE *f = NULL;
bool again = true;
os_filename osfname;
#ifdef __GLIBC__
/*
* Try to open this file with memory mapping for speed, unless we are
* going to do it "manually" with nasm_map_file()
*/
if (!(flags & NF_FORMAP)) {
f = fopen(filename, (flags & NF_TEXT) ? "rtm" : "rbm");
again = (!f) && (errno == EINVAL); /* Not supported, try without m */
}
osfname = os_mangle_filename(filename);
if (osfname) {
os_fopenflag fopen_flags[4];
memset(fopen_flags, 0, sizeof fopen_flags);
fopen_flags[0] = 'r';
fopen_flags[1] = (flags & NF_TEXT) ? 't' : 'b';
#if defined(__GLIBC__) || defined(__linux__)
/*
* Try to open this file with memory mapping for speed, unless we are
* going to do it "manually" with nasm_map_file()
*/
if (!(flags & NF_FORMAP))
fopen_flags[2] = 'm';
#endif
if (again)
f = fopen(filename, (flags & NF_TEXT) ? "rt" : "rb");
while (true) {
f = os_fopen(osfname, fopen_flags);
if (f || errno != EINVAL || !fopen_flags[2])
break;
/* We got EINVAL but with 'm'; try again without 'm' */
fopen_flags[2] = '\0';
}
os_free_filename(osfname);
}
if (!f && (flags & NF_FATAL))
nasm_fatalf(ERR_NOFILE, "unable to open input file: `%s': %s",
@ -127,9 +194,20 @@ FILE *nasm_open_read(const char *filename, enum file_flags flags)
FILE *nasm_open_write(const char *filename, enum file_flags flags)
{
FILE *f;
FILE *f = NULL;
os_filename osfname;
f = fopen(filename, (flags & NF_TEXT) ? "wt" : "wb");
osfname = os_mangle_filename(filename);
if (osfname) {
os_fopenflag fopen_flags[3];
fopen_flags[0] = 'w';
fopen_flags[1] = (flags & NF_TEXT) ? 't' : 'b';
fopen_flags[2] = '\0';
f = os_fopen(osfname, fopen_flags);
os_free_filename(osfname);
}
if (!f && (flags & NF_FATAL))
nasm_fatalf(ERR_NOFILE, "unable to open output file: `%s': %s",
@ -143,43 +221,66 @@ FILE *nasm_open_write(const char *filename, enum file_flags flags)
*/
bool nasm_file_exists(const char *filename)
{
#if defined(HAVE_FACCESSAT) && defined(AT_EACCESS)
return faccessat(AT_FDCWD, filename, R_OK, AT_EACCESS) == 0;
#elif defined(HAVE_ACCESS)
return access(filename, R_OK) == 0;
os_filename osfname;
bool exists;
osfname = os_mangle_filename(filename);
if (!osfname)
return false;
#ifdef os_access
exists = os_access(osfname, R_OK) == 0;
#else
FILE *f;
f = fopen(filename, "rb");
if (f) {
f = os_fopen(osfname, "rb");
exists = f != NULL;
if (f)
fclose(f);
return true;
} else {
return false;
}
#endif
os_free_filename(osfname);
return exists;
}
/*
* Report file size. This MAY move the file pointer.
* Report the file size of an open file. This MAY move the file pointer.
*/
off_t nasm_file_size(FILE *f)
{
#ifdef HAVE__FILELENGTHI64
return _filelengthi64(fileno(f));
#elif defined(nasm_fstat)
nasm_struct_stat st;
off_t where, end;
os_struct_stat st;
if (nasm_fstat(fileno(f), &st))
return (off_t)-1;
if (!os_fstat(fileno(f), &st) && S_ISREG(st.st_mode))
return st.st_size;
/* Do it the hard way... this tests for seekability */
if (fseeko(f, 0, SEEK_CUR))
goto fail; /* Not seekable, don't even try */
where = ftello(f);
if (where == (off_t)-1)
goto fail;
return st.st_size;
#else
if (fseeko(f, 0, SEEK_END))
return (off_t)-1;
goto fail;
return ftello(f);
#endif
end = ftello(f);
if (end == (off_t)-1)
goto fail;
/*
* Move the file pointer back. If this fails, this is probably
* not a plain file.
*/
if (fseeko(f, where, SEEK_SET))
goto fail;
return end;
fail:
return -1;
}
/*
@ -187,26 +288,28 @@ off_t nasm_file_size(FILE *f)
*/
off_t nasm_file_size_by_path(const char *pathname)
{
#ifdef nasm_stat
nasm_struct_stat st;
if (nasm_stat(pathname, &st))
return (off_t)-1;
return st.st_size;
#else
os_filename osfname;
off_t len = -1;
os_struct_stat st;
FILE *fp;
off_t len;
os_fopenflag fopen_flags[3];
fp = nasm_open_read(pathname, NF_BINARY);
if (!fp)
return (off_t)-1;
osfname = os_mangle_filename(pathname);
len = nasm_file_size(fp);
fclose(fp);
if (!os_stat(osfname, &st) && S_ISREG(st.st_mode))
len = st.st_size;
fopen_flags[0] = 'r';
fopen_flags[1] = 'b';
fopen_flags[2] = '\0';
fp = os_fopen(osfname, fopen_flags);
if (fp) {
len = nasm_file_size(fp);
fclose(fp);
}
return len;
#endif
}
/*
@ -214,14 +317,20 @@ off_t nasm_file_size_by_path(const char *pathname)
*/
bool nasm_file_time(time_t *t, const char *pathname)
{
#ifdef nasm_stat
nasm_struct_stat st;
#ifdef os_stat
os_filename osfname;
os_struct_stat st;
bool rv = false;
if (nasm_stat(pathname, &st))
osfname = os_mangle_filename(pathname);
if (!osfname)
return false;
rv = !os_stat(osfname, &st);
*t = st.st_mtime;
return true;
os_free_filename(osfname);
return rv;
#else
return false; /* No idea how to do this on this OS */
#endif

View File

@ -58,70 +58,155 @@
# include <sys/mman.h>
#endif
#if !defined(HAVE_ACCESS) && defined(HAVE__ACCESS)
# define HAVE_ACCESS 1
# define access _access
#endif
#ifndef R_OK
# define R_OK 4 /* Classic Unix constant, same on Windows */
#endif
/* Can we adjust the file size without actually writing all the bytes? */
#ifdef HAVE__CHSIZE_S
# define nasm_ftruncate(fd,size) _chsize_s(fd,size)
# define os_ftruncate(fd,size) _chsize_s(fd,size)
#elif defined(HAVE__CHSIZE)
# define nasm_ftruncate(fd,size) _chsize(fd,size)
# define os_ftruncate(fd,size) _chsize(fd,size)
#elif defined(HAVE_FTRUNCATE)
# define nasm_ftruncate(fd,size) ftruncate(fd,size)
# define os_ftruncate(fd,size) ftruncate(fd,size)
#endif
/*
* On Win32/64, stat has a 32-bit file size but _stati64 has a 64-bit file
* size. Things get complicated because some of these may be macros,
* which autoconf won't pick up on as the standard autoconf tests do
* #undef.
* On Windows, we want to use _wfopen(), as fopen() has a much smaller limit
* on the path length that it supports. Furthermore, we want to prefix the
* path name with \\?\ in order to let the Windows kernel know that
* we are not limited to PATH_MAX characters. Thus, we wrap all the functions
* which take filenames...
*/
#ifdef _stati64
# define HAVE_STRUCT__STATI64 1
# define HAVE__STATI64 1
#endif
#ifdef _fstati64
# define HAVE__FSTATI64 1
#ifdef _WIN32
# include <wchar.h>
typedef wchar_t *os_filename;
typedef wchar_t os_fopenflag;
os_filename os_mangle_filename(const char *filename);
static inline void os_free_filename(os_filename filename)
{
nasm_free(filename);
}
# define os_fopen _wfopen
# define os_access _waccess
/*
* On Win32/64, we have to use the _wstati64() function. Note that
* we can't use _wstat64() without depending on a needlessly new
* version os MSVCRT.
*/
typedef struct _stati64 os_struct_stat;
# define os_stat _wstati64
# define os_fstat _fstati64
#else /* not _WIN32 */
typedef const char *os_filename;
typedef char os_fopenflag;
static inline os_filename os_mangle_filename(const char *filename)
{
return filename;
}
static inline void os_free_filename(os_filename filename)
{
(void)filename; /* Nothing to do */
}
# define os_fopen fopen
#if defined(HAVE_FACCESSAT) && defined(AT_EACCESS)
static inline int os_access(os_filename pathname, int mode)
{
return faccessat(AT_FDCWD, pathname, mode, AT_EACCESS);
}
# define os_access os_access
#elif defined(HAVE_ACCESS)
# define os_access access
#endif
#ifdef HAVE_STRUCT__STATI64
typedef struct _stati64 nasm_struct_stat;
# ifdef HAVE__STATI64
# define nasm_stat _stati64
# endif
# ifdef HAVE__FSTATI64
# define nasm_fstat _fstati64
# endif
#elif defined(HAVE_STRUCT_STAT)
typedef struct stat nasm_struct_stat;
#ifdef HAVE_STRUCT_STAT
typedef struct stat os_struct_stat;
# ifdef HAVE_STAT
# define nasm_stat stat
# define os_stat stat
# endif
# ifdef HAVE_FSTAT
# define nasm_fstat fstat
# define os_fstat fstat
# endif
#else
struct dummy_struct_stat {
int st_mode;
int st_size;
};
typedef struct dummy_struct_stat os_struct_stat;
#endif
#ifndef HAVE_FILENO
# ifdef fileno /* autoconf doesn't always pick up macros */
# define HAVE_FILENO 1
# elif defined(HAVE__FILENO)
# define HAVE_FILENO 1
# define fileno _fileno
# endif
#endif /* Not _WIN32 */
#ifdef S_ISREG
/* all good */
#elif defined(HAVE_S_ISREG)
/* exists, but not a macro */
# define S_ISREG S_ISREG
#elif defined(S_IFMT) && defined(S_IFREG)
# define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
#elif defined(_S_IFMT) && defined(_S_IFREG)
# define S_ISREG(m) (((m) & _S_IFMT) == _S_IFREG)
#endif
/* These functions are utterly useless without fileno() */
#ifndef HAVE_FILENO
# undef nasm_fstat
# undef nasm_ftruncate
#ifdef fileno
/* all good */
#elif defined(HAVE_FILENO)
/* exists, but not a macro */
# define fileno fileno
#elif defined(_fileno) || defined(HAVE__FILENO)
# define fileno _fileno
#endif
#ifndef S_ISREG
# undef os_stat
# undef os_fstat
#endif
/* Disable these functions if they don't support something we need */
#ifndef fileno
# undef os_fstat
# undef os_ftruncate
# undef HAVE_MMAP
# undef HAVE__FILELENGTHI64
#endif
/*
* If we don't have functional versions of these functions,
* stub them out so we don't need so many #ifndefs
*/
#ifndef os_stat
static inline int os_stat(os_filename osfname, os_struct_stat *st)
{
(void)osfname;
(void)st;
return -1;
}
#endif
#ifndef os_fstat
static inline int os_fstat(int fd, os_struct_stat *st)
{
(void)osfname;
(void)st;
return -1;
}
#endif
#ifndef S_ISREG
static inline bool S_ISREG(int m)
{
(void)m;
return false;
}
#endif
#endif /* NASMLIB_FILE_H */