If `r.end` is updated in the `stream` implementation, then it's possible that `r.end += ...` will behave unexpectedly. What seems to happen is that it reverts back to its value before the function call and then the increment happens. Here's a reproduction:
```zig
test "fill when stream modifies `end` and returns 0" {
var buf: [3]u8 = undefined;
var zero_reader = infiniteZeroes(&buf);
_ = try zero_reader.fill(1);
try std.testing.expectEqual(buf.len, zero_reader.end);
}
pub fn infiniteZeroes(buf: []u8) std.Io.Reader {
return .{
.vtable = &.{
.stream = stream,
},
.buffer = buf,
.end = 0,
.seek = 0,
};
}
fn stream(r: *std.Io.Reader, _: *std.Io.Writer, _: std.Io.Limit) std.Io.Reader.StreamError!usize {
@memset(r.buffer[r.seek..], 0);
r.end = r.buffer.len;
return 0;
}
```
When `fill` is called, it will call into `vtable.readVec` which in this case is `defaultReadVec`. In `defaultReadVec`:
- Before the `r.end += r.vtable.stream` line, `r.end` will be 0
- In `r.vtable.stream`, `r.end` is modified to 3 and it returns 0
- After the `r.end += r.vtable.stream` line, `r.end` will be 0 instead of the expected 3
Separating the `r.end += stream();` into two lines fixes the problem (and this separation is done elsewhere in `Reader` so it seems possible that this class of bug has been encountered before).
Potentially related issues:
- https://github.com/ziglang/zig/issues/4021
- https://github.com/ziglang/zig/issues/12064
This clarifies that it is legal to return an invalid pointer from a
function, provided that such pointer is not dereferenced.
This matches current status quo of the language. Any change to this
should be a proposal that argues for different semantics.
It is also legal in C to return a pointer to a local. The C backend
lowers such thing directly, so the corresponding warning in C must be
disabled (`-Wno-return-stack-address`).
Adds `addFileContentArg` and `addPrefixedFileContentArg` to pass the content
of a file with a lazy path as an argument to a `std.Build.Step.Run`.
This enables replicating shell `$()` / cmake `execute_process` with `OUTPUT_VARIABLE`
as an input to another `execute_process` in conjuction with `captureStdOut`/`captureStdErr`.
To also be able to replicate `$()` automatically trimming trailing newlines and cmake
`OUTPUT_STRIP_TRAILING_WHITESPACE`, this patch adds an `options` arg to those functions
which allows specifying the desired handling of surrounding whitespace.
The `options` arg also allows to specify a custom `basename` for the output. e.g.
to add a file extension (concrete use case: Zig `@import()` requires files to have a
`.zig`/`.zon` extension to recognize them as valid source files).
The data structure was originally added in
41e1cd185b and then removed in
50a336fff8, but brought back in
711bf55eaa for Decl in the compiler
frontend, and then the last reference to it was eliminated in
548a087faf which removed Decl in favor of
Nav and Cau.
When building on macOS Tahoe, binaries were getting duplicate LC_RPATH
load commands which caused dyld to refuse to run them with a
"duplicate LC_RPATH" error that has become a hard error.
The duplicates occurred when library directories were being added
to rpath_list twice:
- from lib_directories
- from native system paths detection which includes the same dirs
This can be re-evaluated at a later time, but at the moment the
performance and stability concerns hold it back. Additionally, it
promotes a non-smithing approach to fuzz tests.
This PR significantly improves the capabilities of the fuzzer.
The changes made to the fuzzer to accomplish this feat mostly include
tracking memory reads from .rodata to determine fresh inputs, new
mutations (especially the ones that insert const values from .rodata
reads and __sanitizer_conv_const_cmp), and minimizing found inputs.
Additionally, the runs per second has greatly been increased due to
generating smaller inputs and avoiding clearing the 8-bit pc counters.
An additional feature added is that the length of the input file is now
stored and the old input file is rerun upon start.
Other changes made to the fuzzer include more logical initialization,
using one shared file `in` for inputs, creating corpus files with
proper sizes, and using hexadecimal-numbered corpus files for
simplicity.
Furthermore, I added several new fuzz tests to gauge the fuzzer's
efficiency. I also tried to add a test for zstandard decompression,
which it crashed within 60,000 runs (less than a second.)
Bug fixes include:
* Fixed a race conditions when multiple fuzzer processes needed to use
the same coverage file.
* Web interface stats now update even when unique runs is not changing.
* Fixed tokenizer.testPropertiesUpheld to allow stray carriage returns
since they are valid whitespace.
I’ve been typing `zig fmt **/.zig` for a long time, until I discovered
that the argument can actually be a directory.
Mention this feature explicitly in the help message.
* Remove the generic model; we already have generic_la32 and generic_la64 and
pick appropriately based on bitness.
* Remove the loongarch64 model. We used this as our baseline for 64-bit, but it's
actually pretty misleading and useless; it doesn't represent any real CPU and
has less features than generic_la64.
* Add la64v1_0 and la64v1_1 models.
* Change our baseline CPU model for 64-bit to be la64v1_0, thus adding LSX to
the baseline feature set.
Ascon is the family of cryptographic constructions standardized by NIST
for lightweight cryptography.
The Zig standard library already included the Ascon permutation itself,
but higher-level constructions built on top of it were intentionally
postponed until NIST released the final specification.
That specification has now been published as NIST SP 800-232:
https://csrc.nist.gov/pubs/sp/800/232/final
With this publication, we can now confidently include these constructions
in the standard library.
Andrew Kelley