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.
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?
* rework os.sendfile and add macosx support, and a fallback
implementation for any OS.
* fix sendto compile error
* std.os write functions support partial writes. closes#3443.
* std.os pread / pwrite functions can now return `error.Unseekable`.
* std.fs.File read/write functions now have readAll/writeAll variants
which loop to complete operations even when partial reads/writes
happen.
* Audit std.os read/write functions with respect to Linux returning
EINVAL for lengths greater than 0x7fff0000.
* std.os read/write shim functions do not unnecessarily loop. Since
partial reads/writes are part of the API, the caller will be forced
to loop anyway, and so that would just be code bloat.
* Improve doc comments
* Add a non-trivial test for std.os.sendfile
* Fix std.os.pread on 32 bit Linux
* Add missing SYS_sendfile bit on aarch64
This changset adds a `sendfile(2)` syscall bindings to the linux bits
component. Where available, the `sendfile64(2)` syscall will be
transparently called.
A wrapping function has also been added to the std.os to transform
errno returns to Zig errors.
Change-Id: I86769fc4382c0771e3656e7b21137bafd99a4411
* re-introduce `std.build.Target` which is distinct from `std.Target`.
`std.build.Target` wraps `std.Target` so that it can be annotated as
"the native target" or an explicitly specified target.
* `std.Target.Os` is moved to `std.Target.Os.Tag`. The former is now a
struct which has the tag as well as version range information.
* `std.elf` gains some more ELF header constants.
* `std.Target.parse` gains the ability to parse operating system
version ranges as well as glibc version.
* Added `std.Target.isGnuLibC()`.
* self-hosted dynamic linker detection and glibc version detection.
This also adds the improved logic using `/usr/bin/env` rather than
invoking the system C compiler to find the dynamic linker when zig
is statically linked. Related: #2084
Note: this `/usr/bin/env` code is work-in-progress.
* `-target-glibc` CLI option is removed in favor of the new `-target`
syntax. Example: `-target x86_64-linux-gnu.2.27`
closes#1907
