When calling QueryObjectName, NT namespaced paths can be returned. This
change appropriately strips the prefix to turn it into an absolute path.
(The above behaviour was observed at least in Wine so far)
Co-authored-by: Ryan Liptak <squeek502@hotmail.com>
Previously, fs.path handled a few of the Windows path types, but not all of them, and only a few of them correctly/consistently. This commit aims to make `std.fs.path` correct and consistent in handling all possible Win32 path types.
This commit also slightly nudges the codebase towards a separation of Win32 paths and NT paths, as NT paths are not actually distinguishable from Win32 paths from looking at their contents alone (i.e. `\Device\Foo` could be an NT path or a Win32 rooted path, no way to tell without external context). This commit formalizes `std.fs.path` being fully concerned with Win32 paths, and having no special detection/handling of NT paths.
Resources on Windows path types, and Win32 vs NT paths:
- https://googleprojectzero.blogspot.com/2016/02/the-definitive-guide-on-win32-to-nt.html
- https://chrisdenton.github.io/omnipath/Overview.html
- https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file
API additions/changes/deprecations
- `std.os.windows.getWin32PathType` was added (it is analogous to `RtlDetermineDosPathNameType_U`), while `std.os.windows.getNamespacePrefix` and `std.os.windows.getUnprefixedPathType` were deleted. `getWin32PathType` forms the basis on which the updated `std.fs.path` functions operate.
- `std.fs.path.parsePath`, `std.fs.path.parsePathPosix`, and `std.fs.path.parsePathWindows` were added, while `std.fs.path.windowsParsePath` was deprecated. The new `parsePath` functions provide the "root" and the "kind" of a path, which is platform-specific. The now-deprecated `windowsParsePath` did not handle all possible path types, while the new `parsePathWindows` does.
- `std.fs.path.diskDesignator` has been deprecated in favor of `std.fs.path.parsePath`, and same deal with `diskDesignatorWindows` -> `parsePathWindows`
- `relativeWindows` is now a compile error when *not* targeting Windows, while `relativePosix` is now a compile error when targeting Windows. This is because those functions read/use the CWD path which will behave improperly when used from a system with different path semantics (e.g. calling `relativePosix` from a Windows system with a CWD like `C:\foo\bar` will give you a bogus result since that'd be treated as a single relative component when using POSIX semantics). This also allows `relativeWindows` to use Windows-specific APIs for getting the CWD and environment variables to cut down on allocations.
- `componentIterator`/`ComponentIterator.init` have been made infallible. These functions used to be able to error on UNC paths with an empty server component, and on paths that were assumed to be NT paths, but now:
+ We follow the lead of `RtlDetermineDosPathNameType_U`/`RtlGetFullPathName_U` in how it treats a UNC path with an empty server name (e.g. `\\\share`) and allow it, even if it'll be invalid at the time of usage
+ Now that `std.fs.path` assumes paths are Win32 paths and not NT paths, we don't have to worry about NT paths
Behavior changes
- `std.fs.path` generally: any combinations of mixed path separators for UNC paths are universally supported, e.g. `\/server/share`, `/\server\share`, `/\server/\\//share` are all seen as equivalent UNC paths
- `resolveWindows` handles all path types more appropriately/consistently.
+ `//` and `//foo` used to be treated as a relative path, but are now seen as UNC paths
+ If a rooted/drive-relative path cannot be resolved against anything more definite, the result will remain a rooted/drive-relative path.
+ I've created [a script to generate the results of a huge number of permutations of different path types](https://gist.github.com/squeek502/9eba7f19cad0d0d970ccafbc30f463bf) (the result of running the script is also included for anyone that'd like to vet the behavior).
- `dirnameWindows` now treats the drive-relative root as the dirname of a drive-relative path with a component, e.g. `dirname("C:foo")` is now `C:`, whereas before it would return null. `dirnameWindows` also handles local device paths appropriately now.
- `basenameWindows` now handles all path types more appropriately. The most notable change here is `//a` being treated as a partial UNC path now and therefore `basename` will return `""` for it, whereas before it would return `"a"`
- `relativeWindows` will now do its best to resolve against the most appropriate CWD for each path, e.g. relative for `D:foo` will look at the CWD to check if the drive letter matches, and if not, look at the special environment variable `=D:` to get the shell-defined CWD for that drive, and if that doesn't exist, then it'll resolve against `D:\`.
Implementation details
- `resolveWindows` previously looped through the paths twice to build up the relevant info before doing the actual resolution. Now, `resolveWindows` iterates backwards once and keeps track of which paths are actually relevant using a bit set, which also allows it to break from the loop when it's no longer possible for earlier paths to matter.
- A standalone test was added to test parts of `relativeWindows` since the CWD resolution logic depends on CWD information from the PEB and environment variables
Edge cases worth noting
- A strange piece of trivia that I found out while working on this is that it's technically possible to have a drive letter that it outside the intended A-Z range, or even outside the ASCII range entirely. Since we deal with both WTF-8 and WTF-16 paths, `path[0]`/`path[1]`/`path[2]` will not always refer to the same bits of information, so to get consistent behavior, some decision about how to deal with this edge case had to be made. I've made the choice to conform with how `RtlDetermineDosPathNameType_U` works, i.e. treat the first WTF-16 code unit as the drive letter. This means that when working with WTF-8, checking for drive-relative/drive-absolute paths is a bit more complicated. For more details, see the lengthy comment in `std.os.windows.getWin32PathType`
- `relativeWindows` will now almost always be able to return either a fully-qualified absolute path or a relative path, but there's one scenario where it may return a rooted path: when the CWD gotten from the PEB is not a drive-absolute or UNC path (if that's actually feasible/possible?). An alternative approach to this scenario might be to resolve against the `HOMEDRIVE` env var if available, and/or default to `C:\` as a last resort in order to guarantee the result of `relative` is never a rooted path.
- Partial UNC paths (e.g. `\\server` instead of `\\server\share`) are a bit awkward to handle, generally. Not entirely sure how best to handle them, so there may need to be another pass in the future to iron out any issues that arise. As of now the behavior is:
+ For `relative`, any part of a UNC disk designator is treated as the "root" and therefore isn't applicable for relative paths, e.g. calling `relative` with `\\server` and `\\server\share` will result in `\\server\share` rather than just `share` and if `relative` is called with `\\server\foo` and `\\server\bar` the result will be `\\server\bar` rather than `..\bar`
+ For `resolve`, any part of a UNC disk designator is also treated as the "root", but relative and rooted paths are still elligable for filling in missing portions of the disk designator, e.g. `resolve` with `\\server` and `foo` or `\foo` will result in `\\server\foo`
Fixes#25703Closes#25702
This is relevant to PIEs, which are notably enabled by default on macOS.
The build system needs to only see virtual addresses, that is, those
which do not have the slide applied; but the fuzzer itself naturally
sees relocated addresses (i.e. with the slide applied). We just need to
subtract the slide when we communicate addresses to the build system.
Like ELF, we now have `std.debug.MachOFile` for the host-independent
parts, and `std.debug.SelfInfo.MachO` for logic requiring the file to
correspond to the running program.
Little-endian is what `std.zig.Server` expects, but the old logic just
send the raw bytes of the struct, so sent in native endian (causing a
crash on big-endian targets).
- Affects the following functions:
+ `std.fs.Dir.readLinkW`
+ `std.os.windows.ReadLink`
+ `std.os.windows.ntToWin32Namespace`
+ `std.posix.readlinkW`
+ `std.posix.readlinkatW`
Each of these functions (except `ntToWin32Namespace`) took WTF-16 as input and would output WTF-8, which makes optimal buffer re-use difficult at callsites and could force unnecessary WTF-16 <-> WTF-8 conversion during an intermediate step.
The functions have been updated to output WTF-16, and also allow for the path and the output to re-use the same buffer (i.e. in-place modification), which can reduce the stack usage at callsites. For example, all of `std.fs.Dir.readLink`/`readLinkZ`/`std.posix.readlink`/`readlinkZ`/`readlinkat`/`readlinkatZ` have had their stack usage reduced by one PathSpace struct (64 KiB) when targeting Windows.
The new `ntToWin32Namespace` takes an output buffer and returns a slice from that instead of returning a PathSpace, which is necessary to make the above possible.
The reasoning in the comment deleted by this commit no longer applies, since that same benefit can be obtained by using OpenFile with `.filter = .any`.
Also removes a stray debug.print
The build runner was previously forcing child processes to have their
stderr colorization match the build runner by setting `CLICOLOR_FORCE`
or `NO_COLOR`. This is a nice idea in some cases---for instance a simple
`Run` step which we just expect to exit with code 0 and whose stderr is
not being programmatically inspected---but is a bad idea in others, for
instance if there is a check on stderr or if stderr is captured, in
which case forcing color on the child could cause checks to fail.
Instead, this commit adds a field to `std.Build.Step.Run` which
specifies a behavior for the build runner to employ in terms of
assigning the `CLICOLOR_FORCE` and `NO_COLOR` environment variables. The
default behavior is to set `CLICOLOR_FORCE` if the build runner's output
is colorized and the step's stderr is not captured, and to set
`NO_COLOR` otherwise. Alternatively, colors can be always enabled,
always disabled, always match the build runner, or the environment
variables can be left untouched so they can be manually controlled
through `env_map`.
Notably, this fixes a failure when running `zig build test-cli` in a
TTY (or with colors explicitly enabled). GitHub CI hadn't caught this
because it does not request color, but Codeberg CI now does, and we were
seeing a failure in the `zig init` test because the actual output had
color escape codes in it due to 6d280dc.
