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Rollup merge of rust-lang#92519 - ChrisDenton:command-maybe-verbatim,…
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… r=dtolnay

Use verbatim paths for `process::Command` if necessary

In rust-lang#89174, the standard library started using verbatim paths so longer paths are usable by default. However, `Command` was originally left out because of the way `CreateProcessW` was being called. This was changed as a side effect of rust-lang#87704 so now `Command` paths can be converted to verbatim too (if necessary).
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@Dylan-DPC
Dylan-DPC authored Mar 19, 2022
2 parents 9b701e7 + 93f627d commit ba2d5ed
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Showing 2 changed files with 44 additions and 30 deletions.
67 changes: 39 additions & 28 deletions library/std/src/sys/windows/process.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,12 +19,12 @@ use crate::path::{Path, PathBuf};
use crate::ptr;
use crate::sys::c;
use crate::sys::c::NonZeroDWORD;
use crate::sys::cvt;
use crate::sys::fs::{File, OpenOptions};
use crate::sys::handle::Handle;
use crate::sys::path;
use crate::sys::pipe::{self, AnonPipe};
use crate::sys::stdio;
use crate::sys::{cvt, to_u16s};
use crate::sys_common::mutex::StaticMutex;
use crate::sys_common::process::{CommandEnv, CommandEnvs};
use crate::sys_common::{AsInner, IntoInner};
Expand Down Expand Up @@ -269,8 +269,13 @@ impl Command {
None
};
let program = resolve_exe(&self.program, || env::var_os("PATH"), child_paths)?;
// Case insensitive "ends_with" of UTF-16 encoded ".bat" or ".cmd"
let is_batch_file = matches!(
program.len().checked_sub(5).and_then(|i| program.get(i..)),
Some([46, 98 | 66, 97 | 65, 116 | 84, 0] | [46, 99 | 67, 109 | 77, 100 | 68, 0])
);
let mut cmd_str =
make_command_line(program.as_os_str(), &self.args, self.force_quotes_enabled)?;
make_command_line(&program, &self.args, self.force_quotes_enabled, is_batch_file)?;
cmd_str.push(0); // add null terminator

// stolen from the libuv code.
Expand Down Expand Up @@ -309,7 +314,6 @@ impl Command {
si.hStdOutput = stdout.as_raw_handle();
si.hStdError = stderr.as_raw_handle();

let program = to_u16s(&program)?;
unsafe {
cvt(c::CreateProcessW(
program.as_ptr(),
Expand Down Expand Up @@ -366,7 +370,7 @@ fn resolve_exe<'a>(
exe_path: &'a OsStr,
parent_paths: impl FnOnce() -> Option<OsString>,
child_paths: Option<&OsStr>,
) -> io::Result<PathBuf> {
) -> io::Result<Vec<u16>> {
// Early return if there is no filename.
if exe_path.is_empty() || path::has_trailing_slash(exe_path) {
return Err(io::const_io_error!(
Expand All @@ -388,19 +392,19 @@ fn resolve_exe<'a>(
if has_exe_suffix {
// The application name is a path to a `.exe` file.
// Let `CreateProcessW` figure out if it exists or not.
return Ok(exe_path.into());
return path::maybe_verbatim(Path::new(exe_path));
}
let mut path = PathBuf::from(exe_path);

// Append `.exe` if not already there.
path = path::append_suffix(path, EXE_SUFFIX.as_ref());
if program_exists(&path) {
if let Some(path) = program_exists(&path) {
return Ok(path);
} else {
// It's ok to use `set_extension` here because the intent is to
// remove the extension that was just added.
path.set_extension("");
return Ok(path);
return path::maybe_verbatim(&path);
}
} else {
ensure_no_nuls(exe_path)?;
Expand All @@ -415,7 +419,7 @@ fn resolve_exe<'a>(
if !has_extension {
path.set_extension(EXE_EXTENSION);
}
if program_exists(&path) { Some(path) } else { None }
program_exists(&path)
});
if let Some(path) = result {
return Ok(path);
Expand All @@ -431,10 +435,10 @@ fn search_paths<Paths, Exists>(
parent_paths: Paths,
child_paths: Option<&OsStr>,
mut exists: Exists,
) -> Option<PathBuf>
) -> Option<Vec<u16>>
where
Paths: FnOnce() -> Option<OsString>,
Exists: FnMut(PathBuf) -> Option<PathBuf>,
Exists: FnMut(PathBuf) -> Option<Vec<u16>>,
{
// 1. Child paths
// This is for consistency with Rust's historic behaviour.
Expand Down Expand Up @@ -486,17 +490,18 @@ where
}

/// Check if a file exists without following symlinks.
fn program_exists(path: &Path) -> bool {
fn program_exists(path: &Path) -> Option<Vec<u16>> {
unsafe {
to_u16s(path)
.map(|path| {
// Getting attributes using `GetFileAttributesW` does not follow symlinks
// and it will almost always be successful if the link exists.
// There are some exceptions for special system files (e.g. the pagefile)
// but these are not executable.
c::GetFileAttributesW(path.as_ptr()) != c::INVALID_FILE_ATTRIBUTES
})
.unwrap_or(false)
let path = path::maybe_verbatim(path).ok()?;
// Getting attributes using `GetFileAttributesW` does not follow symlinks
// and it will almost always be successful if the link exists.
// There are some exceptions for special system files (e.g. the pagefile)
// but these are not executable.
if c::GetFileAttributesW(path.as_ptr()) == c::INVALID_FILE_ATTRIBUTES {
None
} else {
Some(path)
}
}
}

Expand Down Expand Up @@ -730,7 +735,12 @@ enum Quote {

// Produces a wide string *without terminating null*; returns an error if
// `prog` or any of the `args` contain a nul.
fn make_command_line(prog: &OsStr, args: &[Arg], force_quotes: bool) -> io::Result<Vec<u16>> {
fn make_command_line(
prog: &[u16],
args: &[Arg],
force_quotes: bool,
is_batch_file: bool,
) -> io::Result<Vec<u16>> {
// Encode the command and arguments in a command line string such
// that the spawned process may recover them using CommandLineToArgvW.
let mut cmd: Vec<u16> = Vec::new();
Expand All @@ -739,17 +749,18 @@ fn make_command_line(prog: &OsStr, args: &[Arg], force_quotes: bool) -> io::Resu
// need to add an extra pair of quotes surrounding the whole command line
// so they are properly passed on to the script.
// See issue #91991.
let is_batch_file = Path::new(prog)
.extension()
.map(|ext| ext.eq_ignore_ascii_case("cmd") || ext.eq_ignore_ascii_case("bat"))
.unwrap_or(false);
if is_batch_file {
cmd.push(b'"' as u16);
}

// Always quote the program name so CreateProcess doesn't interpret args as
// part of the name if the binary wasn't found first time.
append_arg(&mut cmd, prog, Quote::Always)?;
// Always quote the program name so CreateProcess to avoid ambiguity when
// the child process parses its arguments.
// Note that quotes aren't escaped here because they can't be used in arg0.
// But that's ok because file paths can't contain quotes.
cmd.push(b'"' as u16);
cmd.extend_from_slice(prog.strip_suffix(&[0]).unwrap_or(prog));
cmd.push(b'"' as u16);

for arg in args {
cmd.push(' ' as u16);
let (arg, quote) = match arg {
Expand Down
7 changes: 5 additions & 2 deletions library/std/src/sys/windows/process/tests.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,11 +3,12 @@ use super::Arg;
use crate::env;
use crate::ffi::{OsStr, OsString};
use crate::process::Command;
use crate::sys::to_u16s;

#[test]
fn test_raw_args() {
let command_line = &make_command_line(
OsStr::new("quoted exe"),
&to_u16s("quoted exe").unwrap(),
&[
Arg::Regular(OsString::from("quote me")),
Arg::Raw(OsString::from("quote me *not*")),
Expand All @@ -16,6 +17,7 @@ fn test_raw_args() {
Arg::Regular(OsString::from("optional-quotes")),
],
false,
false,
)
.unwrap();
assert_eq!(
Expand All @@ -28,9 +30,10 @@ fn test_raw_args() {
fn test_make_command_line() {
fn test_wrapper(prog: &str, args: &[&str], force_quotes: bool) -> String {
let command_line = &make_command_line(
OsStr::new(prog),
&to_u16s(prog).unwrap(),
&args.iter().map(|a| Arg::Regular(OsString::from(a))).collect::<Vec<_>>(),
force_quotes,
false,
)
.unwrap();
String::from_utf16(command_line).unwrap()
Expand Down

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