Do the alignment dance by ourselves whenever posix_memalign is not
available.
Don't try to use malloc as it has too many edge cases, figuring out
whether a block of memory is manually aligned by the mechanism above or
is directly coming from malloc becomes too hard to be valuable.
Comparisons with absolute epsilons are usually useful when comparing
numbers to zero, for non-zero numbers it's advised to switch to relative
epsilons instead to obtain meaningful results (check [1] for more
details).
The new API introduces approxEqAbs and approxEqRel, where the former
aliases and deprecated the old `approxEq`, allowing the user to pick the
right tool for the job.
The documentation is meant to guide the user in the choice of the
correct alternative.
[1] https://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/
There's no guarantee for the kernel definition to be ABI compatible with
the libc one (and vice versa).
There's also no guarantee of ABI compatibility between musl/glibc.
Fun, isn't it?
With this commit, the function tries to use more efficient syscalls, and
then falls back to non-positional reads.
The motivating use case for this change is to support something like the
following:
try io.getStdOut().writeFileAll(dest_file, .{});
We are checking that two identical, constant values, are stored at
different addresses.
But sharing a unique location doesn't look like something the compiler
wouldn't do.
It may make more sense to check that a const variable and a mutable
variable set to the same value have different addresses.
We read and write bytes directly from the state, but in the init
function, we potentially endian-swap them.
Initialize bytes in native format since we will be reading them
in native format as well later.
Also use the public interface in the "permute" test rather than an
internal interface. The state itself is not meant to be accessed directly,
even in tests.
On Darwin, according to the man pages for setrlimit(), when adjusting
max number of open fds, the reported hard max by getrlimit() is only
theoretical, while the actual maximum, set in the kernel, is hardcoded
in the header file. Therefore, the reported max has to be adjusted
as `min(OPEN_MAX, lim.max)`.
Signed-off-by: Jakub Konka <kubkon@jakubkonka.com>
This commit fixes linking issue on macOS 11 BigSur by appending
a prefix path to all lib and framework search paths known as
`-syslibroot`.
The reason this is needed is that in macOS 11, the system libraries
and frameworks are no longer readily available in the filesystem.
Instead, the new macOS ships with a built-in dynamic linker cache
of all system-provided libraries, and hence, when linking with either
`lld.ld64` or `ld64`, it is required to pass in `-syslibroot [dir]`.
The latter can usually be obtained by invoking `xcrun --show-sdk-path`.
With this commit, Zig will do this automatically when compiling natively
on macOS. However, it also provides a flag `-syslibroot` which can be
used to overwrite the automtically populated value.
To summarise, with this change, the user of Zig is not required to
generate and append their own syslibroot path. Standard invocations
such as `zig build-exe hello.zig` or `zig build` for projects will
work out of the box. The only missing bit is `zig cc` and `zig c++`
since the addition of the `-syslibroot` option would be a mismatch
between the values provided by `clang` itself and Zig's wrapper.
Both `offset` and `len` are `off_t`.
Like the rest of the std lib we assume that `_FILE_OFFSET_BITS == 64`
is always true, so that `off_t` is a `u64`.
When passing to 32-bit kernels, we split these into two `u32`
parameters.
