Use std.heap.FixedBufferAllocator combined with
std.heap.DirectAllocator instead.
std.mem.FixedBufferAllocator is moved to std.heap.FixedBufferAllocator
* DirectAllocator does the underlying syscall for every allocation.
* ArenaAllocator takes another allocator as an argument and
allocates bytes up front, falling back to DirectAllocator with
increasingly large allocation sizes, to avoid calling it too often.
Then the entire arena can be freed at once.
The self hosted parser is updated to take advantage of ArenaAllocator
for the AST that it returns. This significantly reduces the complexity
of cleanup code.
docgen and build runner are updated to use the combination of
ArenaAllocator and DirectAllocator instead of IncrementingAllocator,
which is now deprecated in favor of FixedBufferAllocator combined
with DirectAllocator.
The C allocator calls aligned_alloc instead of malloc, in order to
respect the alignment parameter.
Added asserts in Allocator to ensure that implementors of the
interface return slices of the correct size.
Fixed a bug in Allocator when you call realloc to grow the allocation.
The purpose of this is:
* Only one way to do things
* Changing a function with void return type to return a possible
error becomes a 1 character change, subtly encouraging
people to use errors.
See #632
Here are some imperfect sed commands for performing this update:
remove arrow:
```
sed -i 's/\(\bfn\b.*\)-> /\1/g' $(find . -name "*.zig")
```
add void:
```
sed -i 's/\(\bfn\b.*\))\s*{/\1) void {/g' $(find ../ -name "*.zig")
```
Some cleanup may be necessary, but this should do the bulk of the work.
* add @noInlineCall - see #640
This fixes a crash in --release-safe and --release-fast modes
where the optimizer inlines everything into _start and
clobbers the command line argument data.
If we were able to verify that the user's code never reads
command line args, we could leave off this "no inline"
attribute.
* add i29 and u29 primitive types. u29 is the type of alignment,
so it makes sense to be a primitive.
probably in the future we'll make any `i` or `u` followed by
digits into a primitive.
* add `aligned` functions to Allocator interface
* add `os.argsAlloc` and `os.argsFree` so that you can get
a `[]const []u8`, do whatever arg parsing you want, and then free
it. For now this uses the other API under the hood, but it could
be reimplemented to do a single allocation.
* add tests to make sure command line argument parsing works.
* 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.