This helps prevent errors related to undefined pointers being passed
through to some OS apis when slices have 0 length.
Tests have also been added to catch these cases.
The PCG32 fill function seems to have been copy-pasted from code using u64, so requesting `n` bytes where `(n & 7) > 4` bytes would cause the last few bytes to be all 0.
This fixes a class of bugs on macOS where a segfault happening in
a loaded dylib with no debug info would cause a panic in the panic
handler instead of simply noting that the dylib has no valid debug
info via `error.MissingDebugInfo`. An example could be code linking
some system dylib and causing some routine to segfault on say invalid
pointer value, which should normally cause Zig to print an incomplete
stack trace anchored at the currently loaded image and backtrace all
the way back to the Zig binary with valid debug info. Currently, in
a situation like this we would trigger a panic within a panic.
We definitely want a shared lock on a cache hit. Without this, we get a
deadlock when Zig is asked to compile the same C source file multiple
times as part of the same compilation.
This is a partial revert of 8ccb9a6ad327a4d7fbc321b33d4aa66a27a1f5ee.
cc @kcbanner
- C compilation flows didn't hold an exclusive lock on the cache manifest file when writing to it in all cases
- On windows, explicitly unlock the file lock before closing it
Before this commit, I observe a crash from this abiSize call because the
element type is a struct that is not yet resolved. This is triggered by
running the behavior tests with -ofmt=c -target x86_64-windows.
This is a partial revert of 0d533433e21621177fb291e2a4901bee11834501,
which regressed this behavior. The idea here is to avoid aliases, which
happens when the same function is exported with multiple names. The
problem with aliases is that weak aliases don't seem to work, causing
symbol collisions when multiple of the same symbol are provided, despite
the desired behavior that weak symbols are overridden.
In this case we export redundant functions with different names. Thanks
to -ffunction-sections, the unused functions will be garbage-collected
at link time. This leaves us with the best of both worlds: Zig's
compiler-rt will provide both sets of symbols, and it will be
binary-compatible with different compilers that expect different names,
while still resulting in binaries without garbage.
Override the cache directories because they won't actually help other CI
runs which will be testing alternate versions of zig, and ultimately
would just fill up space on the hard drive for no reason.
In practice we did see one of the CI servers fill up too many files
inside ~/.cache/zig, which caused certain file system operations to
start returning ENOSPC, despite the hard drive having plenty of space
left.
Ran into this when using a program that uses CreateFileMapping and then trying to call `std.fs.createFile` on the mapped file. More info can be found here:
https://stackoverflow.com/questions/41844842/when-error-1224-error-user-mapped-file-occurs
Before:
```
error.Unexpected NTSTATUS=0xc0000243
C:\Users\Ryan\Programming\Zig\zig\lib\std\os\windows.zig:138:40: 0x7ff74e957466 in OpenFile (test.exe.obj)
else => return unexpectedStatus(rc),
^
```
After:
```
FAIL (AccessDenied)
C:\Users\Ryan\Programming\Zig\zig\lib\std\os\windows.zig:137:30: 0x7ff7f5b776ea in OpenFile (test.exe.obj)
.USER_MAPPED_FILE => return error.AccessDenied,
^
```
Test coverage was lacking for chdir() on WASI, allowing this to
regress.
This change makes os.chdir() compile again, and improves the test
logic to use our standard CWD support for WASI.
If a parse node is reserved but never set the node remains
uninitialized and can crash tools doing a linear scan of the nodes
(like ZLS) when switching on the tag.
