Move the declaration of create_file_from_fd to linux/file.h

Author: simonzgx

libc/src/__support/File/file.h

@@ -304,8 +304,6 @@ class File {
 // library.
 ErrorOr<File *> openfile(const char *path, const char *mode);
 
-ErrorOr<File *> create_file_from_fd(int fd, const char *mode);
-
 // The platform_file library should implement it if it relevant for that
 // platform.
 int get_fileno(File *f);

libc/src/__support/File/linux/file.cpp

@@ -119,7 +119,7 @@ ErrorOr<File *> openfile(const char *path, const char *mode) {
   return file;
 }
 
-ErrorOr<File *> create_file_from_fd(int fd, const char *mode) {
+ErrorOr<LinuxFile *> create_file_from_fd(int fd, const char *mode) {
   using ModeFlags = File::ModeFlags;
   ModeFlags modeflags = File::mode_flags(mode);
   if (modeflags == 0) {

libc/src/__support/File/linux/file.h

@@ -29,4 +29,7 @@ class LinuxFile : public File {
   int get_fd() const { return fd; }
 };
 
+// Create a File object and associate it with a fd.
+ErrorOr<LinuxFile *> create_file_from_fd(int fd, const char *mode);
+
 } // namespace LIBC_NAMESPACE

libc/src/stdio/linux/fdopen.cpp

@@ -8,7 +8,7 @@
 
 #include "src/stdio/fdopen.h"
 
-#include "src/__support/File/file.h"
+#include "src/__support/File/linux/file.h"
 #include "src/errno/libc_errno.h"
 
 namespace LIBC_NAMESPACE {