Support _FILE_OFFSET_BITS=64 for most of <stdio.h>.
This doesn't address funopen, but does add fgetpos/fsetpos/fseeko/ftello.
Bug: http://b/24807045
Change-Id: Ibff6f00df5fb699c8e8f13b91a75caf024540b73
diff --git a/libc/stdio/stdio.cpp b/libc/stdio/stdio.cpp
index 7749e0e..23b6971 100644
--- a/libc/stdio/stdio.cpp
+++ b/libc/stdio/stdio.cpp
@@ -433,11 +433,10 @@
}
}
-// TODO: _FILE_OFFSET_BITS=64.
-static off_t __ftello_unlocked(FILE* fp) {
+static off64_t __ftello64_unlocked(FILE* fp) {
// Find offset of underlying I/O object, then adjust for buffered bytes.
__sflush(fp); // May adjust seek offset on append stream.
- fpos_t result = __seek_unlocked(fp, 0, SEEK_CUR);
+ off64_t result = __seek_unlocked(fp, 0, SEEK_CUR);
if (result == -1) {
return -1;
}
@@ -457,29 +456,34 @@
return result;
}
-// TODO: _FILE_OFFSET_BITS=64.
-int fseeko(FILE* fp, off_t offset, int whence) {
+int __fseeko64(FILE* fp, off64_t offset, int whence, int off_t_bits) {
ScopedFileLock sfl(fp);
// Change any SEEK_CUR to SEEK_SET, and check `whence` argument.
// After this, whence is either SEEK_SET or SEEK_END.
if (whence == SEEK_CUR) {
- fpos_t current_offset = __ftello_unlocked(fp);
+ fpos64_t current_offset = __ftello64_unlocked(fp);
if (current_offset == -1) {
- return EOF;
+ return -1;
}
offset += current_offset;
whence = SEEK_SET;
} else if (whence != SEEK_SET && whence != SEEK_END) {
errno = EINVAL;
- return EOF;
+ return -1;
+ }
+
+ // If our caller has a 32-bit interface, refuse to go past a 32-bit file offset.
+ if (off_t_bits == 32 && offset > LONG_MAX) {
+ errno = EOVERFLOW;
+ return -1;
}
if (fp->_bf._base == NULL) __smakebuf(fp);
// Flush unwritten data and attempt the seek.
if (__sflush(fp) || __seek_unlocked(fp, offset, whence) == -1) {
- return EOF;
+ return -1;
}
// Success: clear EOF indicator and discard ungetc() data.
@@ -491,34 +495,46 @@
return 0;
}
-// TODO: _FILE_OFFSET_BITS=64.
-int fseek(FILE* fp, long offset, int whence) {
- return fseeko(fp, offset, whence);
+int fseeko(FILE* fp, off_t offset, int whence) {
+ static_assert(sizeof(off_t) == sizeof(long), "sizeof(off_t) != sizeof(long)");
+ return __fseeko64(fp, offset, whence, 8*sizeof(off_t));
+}
+__strong_alias(fseek, fseeko);
+
+int fseeko64(FILE* fp, off64_t offset, int whence) {
+ return __fseeko64(fp, offset, whence, 8*sizeof(off_t));
}
-// TODO: _FILE_OFFSET_BITS=64.
+int fsetpos(FILE* fp, const fpos_t* pos) {
+ return fseeko(fp, *pos, SEEK_SET);
+}
+
+int fsetpos64(FILE* fp, const fpos64_t* pos) {
+ return fseeko64(fp, *pos, SEEK_SET);
+}
+
off_t ftello(FILE* fp) {
- ScopedFileLock sfl(fp);
- return __ftello_unlocked(fp);
-}
-
-// TODO: _FILE_OFFSET_BITS=64
-long ftell(FILE* fp) {
- off_t offset = ftello(fp);
- if (offset > LONG_MAX) {
+ static_assert(sizeof(off_t) == sizeof(long), "sizeof(off_t) != sizeof(long)");
+ off64_t result = ftello64(fp);
+ if (result > LONG_MAX) {
errno = EOVERFLOW;
return -1;
}
- return offset;
+ return result;
+}
+__strong_alias(ftell, ftello);
+
+off64_t ftello64(FILE* fp) {
+ ScopedFileLock sfl(fp);
+ return __ftello64_unlocked(fp);
}
-// TODO: _FILE_OFFSET_BITS=64
int fgetpos(FILE* fp, fpos_t* pos) {
*pos = ftello(fp);
return (*pos == -1);
}
-// TODO: _FILE_OFFSET_BITS=64
-int fsetpos(FILE* fp, const fpos_t* pos) {
- return fseeko(fp, *pos, SEEK_SET);
+int fgetpos64(FILE* fp, fpos64_t* pos) {
+ *pos = ftello64(fp);
+ return (*pos == -1);
}