Problem:
- Constructors and conversion operators are not `constexpr`,
but they can be.
- `constexpr` is needed here so that other classes can add `constexpr`
evaluation.
Solution:
- Add the `constexpr` keyword to the constructors and
conversion operators.
- Add `static_assert` tests which ensure the capability works.
Previously, when a loop detected an unwind of type ScopeType::Function
(which means a return statement was executed inside of the loop), it
would just return undefined. This set the VM's last_value to undefined,
when it should have been the returned value. This patch makes all loop
statements return the appropriate value in the above case.
This matches behavior on Linux, macOS, Windows, and it makes it possible
to hit ctrl-L arrow-right ctrl-backspace to edit the last component of
an URL in browser, or of the current path in File Manager.
Also make it so that ctrl-left/right does a word movement that starts
at the edge of the selection. This matches Linux and macOS, but not
Windows (which instead does a word movement relative to the cursor,
not the selection edge).
Previously we'd only pick up background-image when it was part of the
background shorthand.
CSS property application remains hackish, lots of room for improvement
in this area. :^)
'continue' is no longer allowed outside of a loop, and an unlabeled
'break' is not longer allowed outside of a loop or switch statement.
Labeled 'break' statements are still allowed everywhere, even if the
label does not exist.
Problem: Defining the destructor violates the "rule of 0" and prevents
the copy/move constructor/assignment operators from being provided by
the compiler.
Solution: Change the constructor and destructor to be the default
compiler-provided definition.
In case we want to rely more on TSC in time keeping in the future, idk
This adds:
- RDTSCP, for when the RDTSCP instruction is available
- CONSTANT_TSC, for when the TSC has a constant frequency, invariant
under things like the CPU boosting its frequency.
- NONSTOP_TSC, for when the TSC doesn't pause when the CPU enters
sleep states.
AMD cpus and newer intel cpus set the INVSTC bit (bit 8 in edx of
extended cpuid 0x8000000008), which implies both CONSTANT_TSC and
NONSTOP_TSC. Some older intel processors have CONSTANT_TSC but not
NONSTOP_TSC; this is set based on cpu model checks.
There isn't a ton of documentation on this, so this follows Linux
terminology and http://blog.tinola.com/?e=54
CONSTANT_TSC:
39b3a79105
NONSTOP_TSC:
40fb17152c
qemu disables invtsc (bit 8 in edx of extended cpuid 0x8000000008)
by default even if the host cpu supports it. It can be enabled by
running with `SERENITY_QEMU_CPU=host,migratable=off` set.
Problem:
- m_data is being passed to the constructor of the parent class before
it is initialized. This is not really a problem because the compiler
knows the location and it is only a span being constructed, but it
triggers a warning in clang for use-before-init.
Solution:
- Initialize using a default constructed array and then overwrite it
inside the constructor after the member is initialized.
Formatter is specialized in the header file. The definition in the
implementation file is extraneous and has no effect. Simply removing
it so that there is no confusion.
The block group indices are 1-based for some reason. Because of that,
we were forgetting to check in the very last block group when doing
block allocation. This caused block allocation to fail even when the
superblock indicated that we had free blocks.
Fixes#3674.
