The class NonCopyable is, like the name says, supposed to disallow
copying. But should it allow moving?
For a long time, NonCopyable used to not allow moving. (It declared
a deleted copy constructor and assigment operator without declaring
a move constructor and assignment operator, making the compiler
implicitly delete the move constructor and assignment operator.)
That's fine if the classes that inherit from NonCopyable don't need
to be movable or if writing the move constructor and assignment
operator by hand is fine, but that's not the case for all classes,
as I discovered when I was working on the DirectoryBlob PR.
Because of that, I decided to make NonCopyable movable in c7602cc,
allowing me to use NonCopyable in DirectoryBlob.h. That was however
an unfortunate decision, because some of the classes that inherit
from NonCopyable have incorrect behavior when moved by default-
generated move constructors and assignment operators, and do not
explicitly delete the move constructors and assignment operators,
relying on NonCopyable being non-movable.
So what can we do about this? There are four solutions that I can
think of:
1. Make NonCopyable non-movable and tell DirectoryBlob to suck it.
2. Keep allowing moving NonCopyable, and expect that classes that
don't support moving will delete the move constructor and
assignment operator manually. Not only is this inconsistent
(having classes disallow copying one way and disallow moving
another way), but deleting the move constructor and assignment
operator manually is too easy to forget compared to how tricky
the resulting problems are.
3. Have one "MovableNonCopyable" and one "NonMovableNonCopyable".
It works, but it feels rather silly...
4. Don't have a NonCopyable class at all. Considering that deleting
the copy constructor and assignment operator only takes two lines
of code, I don't see much of a reason to keep NonCopyable. I
suppose that there was more of a point in having NonCopyable back
in the pre-C++11 days, when it wasn't possible to use "= delete".
I decided to go with the fourth one (like the commit title says).
The implementation of the commit is fairly straight-forward, though
I would like to point out that I skipped adding "= delete" lines
for classes whose only reason for being uncopyable is that they
contain uncopyable classes like File::IOFile and std::unique_ptr,
because the compiler makes such classes uncopyable automatically.
Some code was calling more than one of these functions in a row
(in particular, FileUtil.cpp itself did it a lot...), which is
a waste since it's possible to call stat a single time and then
read all three values from the stat struct. This commit adds a
File::FileInfo class that calls stat once on construction and
then lets Exists/IsDirectory/GetSize be executed very quickly.
The performance improvement mostly matters for functions that
can be handling a lot of files, such as File::ScanDirectoryTree.
I've also done some cleanup in code that uses these functions.
For instance, some code had checks like !Exists() || !IsDirectory(),
which is functionally equivalent to !IsDirectory(), and some
code was using File::GetSize even though there was an IOFile
object that the code could call GetSize on.
Certain parts of the standard library try to determine whether or not a
transfer operation should either be a copy or a move. The prevalent notion
of move constructors/assignment operators is that they should not throw,
they simply move an already existing resource somewhere else.
This is typically done with 'std::move_if_noexcept'. Like the name says,
if a type's move constructor is noexcept, then the functions retrieves an
r-value reference (for move semantics), or an l-value (for copy semantics)
if it is not noexcept.
As IOFile deletes the copy constructor and copy assignment operators,
using IOFile with certain parts of the standard library can fail in
unexcepted ways (especially when used with various container
implementations). This prevents that.
'operator void*' is basically a pre-C++11-ism that was used, as C++03
only had the notion of implicit type-conversion operators, but not explicit type
conversion operators (allowing implicit conversion of a file handle to
bool can go downhill pretty quickly).
This reverts commit 141f3bfb3a.
The implementation of getting absolute paths wasn't working
on non-Windows systems, which is a huge problem for IOS HLE.
- Change the path of the Sys folder to the executable's location
- Add LINUX_LOCAL_DEV flag to use relocatable version on Linux
- Add CMake definition for relocatable build
Currently only works on unix, but can be extended to other systems. Can
also be extended to do wiimotes.
Searches the Pipes folder for readable named pipes and creates a dolphin
input device out of them. Send controller inputs to the game by writing
to the file. Commands are described in Pipes.h.
Eventually, netplay will be able to use the host's NAND, but this could
still be useful in some cases; for TAS it definitely makes sense to have
a way to avoid using any preexisting NAND.
In terms of implementation: remove D_WIIUSER_IDX, which was just WIIROOT
+ "/", as well as some other indices which are pointless to have as
separate variables rather than just using the actual path (fixed, since
they're actual Wii NAND paths) at the call site. Then split off
D_SESSION_WIIROOT_IDX, which can point to the dummy NAND directory, from
D_WIIROOT_IDX, which always points to the "real" one the user
configured.
- FileSearch is now just one function, and it converts the original glob
into a regex on all platforms rather than relying on native Windows
pattern matching on there and a complete hack elsewhere. It now
supports recursion out of the box rather than manually expanding
into a full list of directories in multiple call sites.
- This adds a GCC >= 4.9 dependency due to older versions having
outright broken <regex>. MSVC is fine with it.
- ScanDirectoryTree returns the parent entry rather than filling parts
of it in via reference. The count is now stored in the entry like it
was for subdirectories.
- .glsl file search is now done with DoFileSearch.
- IOCTLV_READ_DIR now uses ScanDirectoryTree directly and sorts the
results after replacements for better determinism.
With my previous changes Dolphin would fail to create the user directory if it didn't exist, and would dump all the configuration options in to the cwdir.
This was a bit more complicated to fix in a clean fashion, so I took to moving around code concerning user directories.
Instead of having GetUserPath serve a dual purpose of both getting and setting our user directories, break out to a new SetUserPath function.
GetUserPath will know only get the configured user path.
SetUserPath will set our user paths and setup the internal user path state.
This ending up being a lot cleaner overall, which is nice. Also less mind bending when attempting to read the code.
So now we won't dump all of our configuration in to the cwdir if ~/.dolphin-emu isn't found.
Fixes issue 8371.
Pierre Bourdon