Can occur when trying to open a directory for iteration but the 'List folder contents' permission of the directory is set to 'Deny'.
This was found because it was being triggered during PATH searching in ChildProcess.spawnWindows if a PATH entry did not have 'List folder contents' permission, so this fixes that as well (note: the behavior on hitting this during PATH searching is to treat it as the directory not existing and therefore will fail to find any executables in a directory in the PATH without 'List folder contents' permission; this matches Windows behavior which also fails to find commands in directories that do not have 'List folder contents' permission).
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.
This is a partial revert of 0d533433e2,
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.
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.
While it is already mentioned on the `items` attributes of the structs, it is
interesting to comment in every method potentially invalidating pointers to items
that they may do so.
