This function is needed for Go 1.22, and is used from various packages
like math/rand.
When there is no random number generator available, it falls back to a
static sequence of numbers. I think this is fine, because as far as I
can see it is only used for non-cryptographic needs.
Instead of markGlobals calling markRoots unconditionally (which doesn't
make sense for -gc=none and -gc=leaking), provide markRoots as a
callback function.
This is in preparation for -gc=boehm, where the previous design is even
more awkward and a callback makes far more sense.
I've tested the size impact using `make smoketest XTENSA=0`. There is
none, except for two cases:
* One with `-opt=0` so const-propagation for the callback didn't take
place.
* One other on AVR, I don't know why but as it's only 16 bytes in a
very specific case I'm going to assume it's just a random change in
compiler output that caused a size difference.
We have an optimization for this specific pattern, but it's really just
a hack. With the addition of unsafe.Add in Go 1.17 we can directly
specify the intent instead and eventually remove this special case.
The code is also easier to read.
Unfortunately the calling convention for variadic functions is different from
the calling convention of regular functions on darwin/arm64, and open happens
to be such a variadic function. The syscall package treated it like a regular
function, which resulted in buggy behavior.
This fix introduces a wrapper function. This is the cleanest change I could
come up with.
Go 1.19 started reformatting code in a way that makes it more obvious
how it will be rendered on pkg.go.dev. It gets it almost right, but not
entirely. Therefore, I had to modify some of the comments so that they
are formatted correctly.
This replaces "precise" global scanning in LLVM with conservative
scanning of writable MachO segments. Eventually I'd like to get rid of
the AddGlobalsBitmap pass, and this is one step towards that goal.
Do it all at once in preparation for Go 1.18 support.
To make this commit, I've simply modified the `fmt-check` Makefile
target to rewrite files instead of listing the differences. So this is a
fully mechanical change, it should not have introduced any errors.
This function previously returned the atomic time, that isn't affected
by system time changes but also has a time base at some arbitrary time
in the past. This makes sense for baremetal platforms (which typically
don't know the wall time) but it gives surprising results on Linux and
macOS: time.Now() usually returns a time somewhere near the start of
1970.
This commit fixes this by obtaining both time values: the monotonic time
and the wall clock time. This is also how the Go runtime implements the
time.now function.
This commit does two things:
1. It makes it possible to grow the heap on Linux and MacOS by
allocating 1GB of virtual memory on startup and then slowly using it
as necessary, when running out of available heap space.
2. It switches the default GC to be the conservative GC (previously
extalloc). This is good for consistency with other platforms that
all use this same GC.
This makes the extalloc GC unused by default.
dkegel-fastly
Ayke van Laethem
Yurii Soldak