699b4bbab9
To quote jscipione (from95e8362c52), "Let me tell you a story about a bug" -- though this tale spans a much lesser time than that one did. In5e19679ea3, I enabled libroot_build for Haiku, instead of using the system libroot as we had before. There were a number of bugs introduced along with this that I hadn't fixed (and there may be more after this), but most of the obvious ones (crashes on x86_64...) were fixed shortly enough. Attribute usage, though, was a different story. Unlike most of the POSIX calls in libroot, which were aliasing system functions no matter what the platform, the attribute calls were not, as they are specific to Haiku. Initially I had completely forgot about them, and it wasn't until a few days later when I noticed that I had an "attributes" directory in my generated that I realized that the "generic" attribute layer was being used on Haiku. I attempted a fix for this in5e19679ea3, thinking that would clear the problem up, but I didn't actually run a test beyond seeing that my BuildConfig had been updated properly. In fact, BuildSetup was hard-wired to not even pass that definition through on Haiku, and so that commit had in effect caused nothing. My initial "fix" of just changing BuildSetup then caused a build failure, as while libroot_build itself compiled, it ran into errors whenever attributes were used, because in letting the real libroot's attribute calls shine through, I had bypassed libroot_build's FD emulation/shim layer. Then I tried and failed at three separate attempts to solve this with code: - a version of the "fs_attr_...h" interface for Haiku. This proved possible in theory, but in practice I would need to reimplement a lot of attribute handling code in it, because all I had access to from there was syscalls. - a version of "fs_attr_untyped" that bypassed its reimplementations of the "fs*attr" functions for the libroot ones, only using the FD shim layer. This proved possibly not even theoretically possible because it would have caused preprocessor hell in some of the build headers, and also assumptions about how attributes are read were totally different. - a completely new "fs_attr_haiku" that was a completely new interface to the fs*attr functions. This proved practically impossible because of the need to include structures from the system libroot to call out to readdir, etc. that attempts to solve would also have caused preprocessor hell. Then I realized that the Linux xattr emulation library, which I'd used as a reference when attempting the first solution, was shipped by default as a system library in all builds of Haiku ... and so I could just tell fs_attr_untyped to use the Linux xattr handler, and then link against libgnu. So that is how I arrived at this strange and decidedly unorthodox solution to a problem of my own creation.
65 lines
1.9 KiB
C
65 lines
1.9 KiB
C
/*
|
|
* Copyright 2002-2009, Haiku Inc. All Rights Reserved.
|
|
* Distributed under the terms of the MIT License.
|
|
*/
|
|
#ifndef _FS_ATTR_H
|
|
#define _FS_ATTR_H
|
|
|
|
|
|
#include <OS.h>
|
|
#include <dirent.h>
|
|
|
|
|
|
typedef struct attr_info {
|
|
uint32 type;
|
|
off_t size;
|
|
} attr_info;
|
|
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
|
|
/* Since libroot_build is also used on Haiku and linked against the real
|
|
* libroot which also has the fs*attr functions, these must be shadowed. */
|
|
#define fs_read_attr build_fs_read_attr
|
|
#define fs_write_attr build_fs_write_attr
|
|
#define fs_remove_attr build_fs_remove_attr
|
|
#define fs_stat_attr build_fs_stat_attr
|
|
#define fs_open_attr build_fs_open_attr
|
|
#define fs_fopen_attr build_fs_fopen_attr
|
|
#define fs_close_attr build_fs_close_attr
|
|
#define fs_open_attr_dir build_fs_open_attr_dir
|
|
#define fs_fopen_attr_dir build_fs_fopen_attr_dir
|
|
#define fs_close_attr_dir build_fs_close_attr_dir
|
|
#define fs_read_attr_dir build_fs_read_attr_dir
|
|
#define fs_rewind_attr_dir build_fs_rewind_attr_dir
|
|
|
|
|
|
extern ssize_t fs_read_attr(int fd, const char *attribute, uint32 type,
|
|
off_t pos, void *buffer, size_t readBytes);
|
|
extern ssize_t fs_write_attr(int fd, const char *attribute, uint32 type,
|
|
off_t pos, const void *buffer, size_t readBytes);
|
|
extern int fs_remove_attr(int fd, const char *attribute);
|
|
extern int fs_stat_attr(int fd, const char *attribute,
|
|
struct attr_info *attrInfo);
|
|
|
|
extern int fs_open_attr(const char *path, const char *attribute,
|
|
uint32 type, int openMode);
|
|
extern int fs_fopen_attr(int fd, const char *attribute, uint32 type,
|
|
int openMode);
|
|
extern int fs_close_attr(int fd);
|
|
|
|
extern DIR *fs_open_attr_dir(const char *path);
|
|
extern DIR *fs_fopen_attr_dir(int fd);
|
|
extern int fs_close_attr_dir(DIR *dir);
|
|
extern struct dirent *fs_read_attr_dir(DIR *dir);
|
|
extern void fs_rewind_attr_dir(DIR *dir);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* _FS_ATTR_H */
|