Avoid using unions for LongDirEntry.

GCC still assumes that the dirent has no data past the end for some
scenarios here and still mis-optimizes things. Therefore, drop the
usages of unions altogether, and instead use a casted character array.

Additionally, use B_FILE_NAME_LENGTH for the array, not B_PATH_NAME_LENGTH,
and make sure to add 1 for the NULL terminator.

libroot_build: Use a union for dirent structures.

Same fixe as applied to the rest of the Storage Kit a few commits ago.

libroot_build: Full passthrough to system attributes.

As it turns out, using the xattr emulation layer plus "libgnu"
causes some strange mixups at package build time, and so packages
built with it were winding up with no attributes at all.

So I've just bitten the bullet and written a full passthrough layer
to the system attributes. Verified using a full build of haiku.hpkg
this time ... after a lot of painful debugging of symlink mixups.

Hopefully I am finally rid of this plague...

libroot_build: *Actually* fix attribute usage on Haiku.

To quote jscipione (from 95e8362c52af35a4012ca4d0facd62fb9856b619),
"Let me tell you a story about a bug" -- though this tale spans a much
lesser time than that one did.

In 5e19679ea35a79a26477c6215c7abba9bb7c4d00, 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 in 5e19679ea35a79a26477c6215c7abba9bb7c4d00,
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.

libroot_build: Fix fs_read_attr() in fs_attr_untyped.cpp

* With a specified buffer size smaller than the attribute size the
function would fail with ERANGE on Linux although it should just read
as much as possible. Now we always read into our temporary data buffer
with the full buffer size.
* Fix return value in case pos is > 0. pos must be subtracted from the
bytes actually read.

fs_write_attr(): Allow 0-length NULL buffer

Open/close attribute support for xattrs backend

For the xattr/BSD (untyped) attribute backend implement fs_fopen_attr()
and fs_close_attr(). A new AttributeDescriptor is created. It is
currently used in write_pos() only.

fs_write_attr(): Allow 0-length NULL buffer

Open/close attribute support for xattrs backend

For the xattr/BSD (untyped) attribute backend implement fs_fopen_attr()
and fs_close_attr(). A new AttributeDescriptor is created. It is
currently used in write_pos() only.

Fixed warning when building with 64 bit compiler.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34200 a95241bf-73f2-0310-859d-f6bbb57e9c96

Patch by Vincent Duvert: Added support for BSDish xattrs.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32841 a95241bf-73f2-0310-859d-f6bbb57e9c96

Refactored the BeOS attribute emulation using xattr a bit:
* Renamed fs_attr_xattr.cpp to libroot/fs_attr_untyped.cpp.
* Pulled the xattr specifics into a separate fs_attr_xattr.h.
* Added fs_attr_extattr.h, interfacing with FreeBSD's extattr support.
Totally untested yet. Might not even compile.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27350 a95241bf-73f2-0310-859d-f6bbb57e9c96

libroot_build: Fix fs_read_attr() in fs_attr_untyped.cpp

* With a specified buffer size smaller than the attribute size the
function would fail with ERANGE on Linux although it should just read
as much as possible. Now we always read into our temporary data buffer
with the full buffer size.
* Fix return value in case pos is > 0. pos must be subtracted from the
bytes actually read.

fs_write_attr(): Allow 0-length NULL buffer

Open/close attribute support for xattrs backend

For the xattr/BSD (untyped) attribute backend implement fs_fopen_attr()
and fs_close_attr(). A new AttributeDescriptor is created. It is
currently used in write_pos() only.

fs_write_attr(): Allow 0-length NULL buffer

Open/close attribute support for xattrs backend

For the xattr/BSD (untyped) attribute backend implement fs_fopen_attr()
and fs_close_attr(). A new AttributeDescriptor is created. It is
currently used in write_pos() only.

Fixed warning when building with 64 bit compiler.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34200 a95241bf-73f2-0310-859d-f6bbb57e9c96

Patch by Vincent Duvert: Added support for BSDish xattrs.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32841 a95241bf-73f2-0310-859d-f6bbb57e9c96

Refactored the BeOS attribute emulation using xattr a bit:
* Renamed fs_attr_xattr.cpp to libroot/fs_attr_untyped.cpp.
* Pulled the xattr specifics into a separate fs_attr_xattr.h.
* Added fs_attr_extattr.h, interfacing with FreeBSD's extattr support.
Totally untested yet. Might not even compile.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27350 a95241bf-73f2-0310-859d-f6bbb57e9c96