Add fallback paths for when the getrandom(2) system call is not
available. Try /dev/urandom first and sysctl(RANDOM_UUID) second.
The sysctl issues a warning in the system logs with some kernels but
that seems like an acceptable tradeoff for the fallback of a fallback.
These are on the slower side and could be improved. No performance optimizations
yet have been done.
```
Cpu: Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz
```
-- Sha3-256
```
Zig --release-fast
93 Mb/s
Zig --release-safe
99 Mb/s
Zig
4 Mb/s
```
-- Sha3-512
```
Zig --release-fast
49 Mb/s
Zig --release-safe
54 Mb/s
Zig
2 Mb/s
```
Interestingly, release-safe is producing slightly better code than
release-fast.
Some performance comparisons to C.
We take the fastest time measurement taken across multiple runs.
The block hashing functions use the same md5/sha1 methods.
```
Cpu: Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz
Gcc: 7.2.1 20171224
Clang: 5.0.1
Zig: 0.1.1.304f6f1d
```
See https://www.nayuki.io/page/fast-md5-hash-implementation-in-x86-assembly:
```
gcc -O2
661 Mb/s
clang -O2
490 Mb/s
zig --release-fast and zig --release-safe
570 Mb/s
zig
50 Mb/s
```
See https://www.nayuki.io/page/fast-sha1-hash-implementation-in-x86-assembly:
```
gcc -O2
588 Mb/s
clang -O2
563 Mb/s
zig --release-fast and zig --release-safe
610 Mb/s
zig
21 Mb/s
```
In short, zig provides pretty useful tools for writing this sort of
code. We are in the lead against clang (which uses the same LLVM
backend) with us being slower only against md5 with GCC.
* Merge io.InStream and io.OutStream into io.File
* Introduce io.OutStream and io.InStream interfaces
- io.File implements both of these
* Move mem.IncrementingAllocator to heap.IncrementingAllocator
Instead of:
```
%return std.io.stderr.printf("hello\n");
```
now do:
```
std.debug.warn("hello\n");
```
To print to stdout, see `io.getStdOut()`.
* Rename std.ArrayList.resizeDown to std.ArrayList.shrink.
* skip installing std/rand_test.zig as it's not needed beyond running
the std lib tests
* add std.math.floor function
* add setFloatMode builtin function to choose between
builtin.FloatMode.Optimized (default) and builtin.FloatMode.Strict
(Optimized is equivalent to -ffast-math in gcc)
See #329
Supporting work:
* move std.cstr.Buffer0 to std.buffer.Buffer
* add build.zig to example/shared_library/ and add an automated test
for it
* add std.list.List.resizeDown
* improve std.os.makePath
- no longer recursive
- takes into account . and ..
* add std.os.path.isAbsolute
* add std.os.path.resolve
* reimplement std.os.path.dirname
- no longer requires an allocator
- handles edge cases correctly
* `zig build --export [obj|lib|exe]` changed to `zig build_obj`,
`zig build_lib` and `zig build_exe` respectively.
* `--name` parameter is optional when it can be inferred from the
root source filename. closes#207
* `zig build` now looks for `build.zig` which interacts with
`std.build.Builder` to describe the targets, and then the zig
build system prints TODO: build these targets. See #204
* add `@bitcast` which is mainly used for pointer reinterpret
casting and make explicit casting not do pointer reinterpretation.
Closes#290
* fix debug info for byval parameters
* sort command line help options
* `std.debug.panic` supports format string printing
* add `std.mem.IncrementingAllocator`
* fix const ptr to a variable with data changing at runtime.
closes#289
* introduce zigrt file. it contains only weak symbols so that
multiple instances can be merged. it contains __zig_panic
so that multiple .o files can call the same panic function.
* remove `@setFnVisible` builtin and add @setGlobalLinkage builtin
which is more powerful
* add `@panic` builtin function.
* fix collision of symbols with extern prototypes and internal
function names
* add stack protector safety when linking against libc. To add
the safety mechanism without libc requires implementing
Thread Local Storage. See #276
* standard library knows if it is linking against libc and will
sometimes call libc functions in that case instead of providing
redundant definitions
* fix infinite loop bug when resolving use declarations
* allow calling the same C function from different C imports.
closes#277
* push more logic from compiler to std/bootstrap.zig
* standard library provides way to access errno
closes#274
* fix compile error in standard library for windows
* add implementation of getRandomBytes for windows
remove "unnecessary if statement" error
this "depends on compile variable" code is too hard to validate,
and has false negatives. not worth it right now.
std.str removed, instead use std.mem.
std.mem.eql and std.mem.sliceEql merged and do not require explicit
type argument.
* instead of emitting a breakpoint for a debug safety crash,
zig calls a panic function which prints an error message
and a stack trace and then calls abort.
* on freestanding OS, this panic function has a default
implementation of a simple infinite loop.
* users can override the panic implementation by providing
`pub fn panic(message: []const u8) -> unreachable { }`
* workaround for LLVM segfaulting when you try to use cold
calling convention on ARM.
closes#245
