Implement funopen64.
Bug: http://b/24807045
Change-Id: I161920978161389be34b707cc6ce8e05f760d552
diff --git a/libc/stdio/local.h b/libc/stdio/local.h
index 524e6de..7fe339a 100644
--- a/libc/stdio/local.h
+++ b/libc/stdio/local.h
@@ -72,7 +72,6 @@
// Function pointers used by `funopen`.
// Note that `_seek` is ignored if `_seek64` (in __sfileext) is set.
- // TODO: implement `funopen64`.
// TODO: NetBSD has `funopen2` which corrects the `int`s to `size_t`s.
// TODO: glibc has `fopencookie` which passes the function pointers in a struct.
void* _cookie; /* cookie passed to io functions */
diff --git a/libc/stdio/stdio.cpp b/libc/stdio/stdio.cpp
index 23b6971..2139621 100644
--- a/libc/stdio/stdio.cpp
+++ b/libc/stdio/stdio.cpp
@@ -538,3 +538,56 @@
*pos = ftello64(fp);
return (*pos == -1);
}
+
+static FILE* __funopen(const void* cookie,
+ int (*read_fn)(void*, char*, int),
+ int (*write_fn)(void*, const char*, int),
+ int (*close_fn)(void*)) {
+ if (read_fn == nullptr && write_fn == nullptr) {
+ errno = EINVAL;
+ return nullptr;
+ }
+
+ FILE* fp = __sfp();
+ if (fp == nullptr) return nullptr;
+
+ if (read_fn != nullptr && write_fn != nullptr) {
+ fp->_flags = __SRW;
+ } else if (read_fn != nullptr) {
+ fp->_flags = __SRD;
+ } else if (write_fn != nullptr) {
+ fp->_flags = __SWR;
+ }
+
+ fp->_file = -1;
+ fp->_cookie = const_cast<void*>(cookie); // The funopen(3) API is incoherent.
+ fp->_read = read_fn;
+ fp->_write = write_fn;
+ fp->_close = close_fn;
+
+ return fp;
+}
+
+FILE* funopen(const void* cookie,
+ int (*read_fn)(void*, char*, int),
+ int (*write_fn)(void*, const char*, int),
+ fpos_t (*seek_fn)(void*, fpos_t, int),
+ int (*close_fn)(void*)) {
+ FILE* fp = __funopen(cookie, read_fn, write_fn, close_fn);
+ if (fp != nullptr) {
+ fp->_seek = seek_fn;
+ }
+ return fp;
+}
+
+FILE* funopen64(const void* cookie,
+ int (*read_fn)(void*, char*, int),
+ int (*write_fn)(void*, const char*, int),
+ fpos64_t (*seek_fn)(void*, fpos64_t, int),
+ int (*close_fn)(void*)) {
+ FILE* fp = __funopen(cookie, read_fn, write_fn, close_fn);
+ if (fp != nullptr) {
+ _EXT(fp)->_seek64 = seek_fn;
+ }
+ return fp;
+}