Fixes https://bugs.dolphin-emu.org/issues/12327.
When we started using fmt in CheckExternalExceptions, JitArm64
mysteriously stopped working even though the code path where
fmt was used never was reached. This is because the compiler
added a function prologue and epilogue to set up the stack,
since the code path that used fmt required the use of the stack.
However, the breakage didn't actually have anything to do
with the usage of the stack in itself, but rather with the
compiler's insertion of a stack canary. In the function
epilogue, a cmp instruction was inserted to check that the
stack canary had not been overwritten during the execution
of the function. This cmp instruction overwriting the status
flags ended up having a disastrous side effect once execution
returned to code emitted by JitArm64::WriteExceptionExit.
JitArm64's dispatcher contains a branch to the "do_timing"
code which is intended to be taken if the PPC downcount is
negative. However, the dispatcher doesn't update the status
flags on its own before this conditional branch, but rather
expects the calling code to have set them as a side effect
of DoDownCount. The root cause of our bug was that
JitArm64::WriteExceptionExit was calling DoDownCount before
Check(External)Exceptions instead of after.
1. Comparing string_views does not behave the same as strncmp
in the case where SConfig's game ID is longer than 6 chars.
2. DTMHeader::GetGameID wasn't excluding null bytes for game IDs
shorter than 6 chars.
3. == was accidentally used instead of !=.
This issue is both severe and surprisingly difficult to find
the root cause of, so I think it would make sense to add a simple
hotfix for now. https://bugs.dolphin-emu.org/issues/12327
Fallback Region
A user-selected fallback to use instead of the default PAL
This is used for unknown region or region free titles to give them
the ability to force region to use. This replaces the current fallback region
of PAL. This can be useful if a user is trying to play a region free
tilte that is originally NTSC and expects to be run at NTSC speeds. This
may be done when a user attempts to dump a WAD of their own without
understanding the settings they have chosen, or could be an intentional
decision by a developer of a ROM hack that can be injected into a
Virtual Console WAD.
Remove using System Menu region being checked in GetFallbackRegion
Use DiscIO::Region instead of std::String for fallback
Add explanation text for Fallback Region
Unfortunately, adding a DEBUG_ASSERT_MSG_FMT isn't actually possible
right now because of compiler bugs:
https://github.com/dolphin-emu/dolphin/pull/9284
We could require a newer version of GCC (10) but that would require
updating GCC on the build machines.
For what it's worth, older versions of GCC (8, 9) are broken in
many ways: adding constexpr to some Matrix functions causes GCC 8
to generate bugged code that causes the Wii IR pointer to disappear,
which means that the generated builds are already unusable
(see https://dolp.in/i12324).
Additionally, we've already had to add workarounds for those versions
in the format macros to fix compilation bugs. This time, it looks like
workarounds won't cut it; even applying the workaround
described in https://github.com/fmtlib/fmt/pull/1580 does not help.
Converts the remaining PowerPC code over to fmt-capable logging.
Now, all that's left to convert over are the lingering remnants within
the frontend code.
gameID isn't null terminated since it is just an std::array<char, 6>
and .data() returns a char* so {fmt} would go way beyond the bounds of
the array when it attempts to determine the length of the string.
The fix is to pass a std::string_view to {fmt}. This commit adds
a GetGameID() function that can also be used to simplify
string comparisons.
PR #9260 made the MsgAlert macros use lambdas so that local
constexpr variables can be added while keeping the ability to
return a boolean from the macros.
Unfortunately, C++17 forbids referring to structured bindings in lambda
captures. This is fixed in P1091R3 but we cannot rely on C++20 yet...
We want to use positional arguments in translatable strings
that have more than one argument so that translators can change
the order of them, but the question is: Should we also use
positional arguments in translatable strings with only one
argument? I think it makes most sense that way, partially
so that translators don't even have to be aware of the
non-positional syntax and partially because "translatable
strings use positional arguments" is an easier rule for us
to remember than "transitional strings which have more than
one argument use positional arguments". But let me know if
you have a different opinion.
Time for yet another new iteration of working around the
"surface destruction during boot" problem...
This time, the strategy is to use a mutex in MainAndroid.cpp.
