Rollup merge of #126488 - ChrisDenton:absolute, r=albertlarsan68

Use `std::path::absolute` in bootstrap

`std::path::absolute` is now stable in 1.79 so we can get rid of the copy-pasted version.

Author: matthiaskrgr

src/bootstrap/src/core/config/config.rs

@@ -10,7 +10,7 @@ use std::env;
 use std::fmt::{self, Display};
 use std::fs;
 use std::io::IsTerminal;
-use std::path::{Path, PathBuf};
+use std::path::{absolute, Path, PathBuf};
 use std::process::Command;
 use std::str::FromStr;
 use std::sync::OnceLock;
@@ -1437,7 +1437,7 @@ impl Config {
         // To avoid writing to random places on the file system, `config.out` needs to be an absolute path.
         if !config.out.is_absolute() {
             // `canonicalize` requires the path to already exist. Use our vendored copy of `absolute` instead.
-            config.out = crate::utils::helpers::absolute(&config.out);
+            config.out = absolute(&config.out).expect("can't make empty path absolute");
         }
 
         config.initial_rustc = if let Some(rustc) = rustc {

src/bootstrap/src/utils/helpers.rs

@@ -331,115 +331,6 @@ fn dir_up_to_date(src: &Path, threshold: SystemTime) -> bool {
     })
 }
 
-/// Copied from `std::path::absolute` until it stabilizes.
-///
-/// FIXME: this shouldn't exist.
-pub(crate) fn absolute(path: &Path) -> PathBuf {
-    if path.as_os_str().is_empty() {
-        panic!("can't make empty path absolute");
-    }
-    #[cfg(unix)]
-    {
-        t!(absolute_unix(path), format!("could not make path absolute: {}", path.display()))
-    }
-    #[cfg(windows)]
-    {
-        t!(absolute_windows(path), format!("could not make path absolute: {}", path.display()))
-    }
-    #[cfg(not(any(unix, windows)))]
-    {
-        println!("WARNING: bootstrap is not supported on non-unix platforms");
-        t!(std::fs::canonicalize(t!(std::env::current_dir()))).join(path)
-    }
-}
-
-#[cfg(unix)]
-/// Make a POSIX path absolute without changing its semantics.
-fn absolute_unix(path: &Path) -> io::Result<PathBuf> {
-    // This is mostly a wrapper around collecting `Path::components`, with
-    // exceptions made where this conflicts with the POSIX specification.
-    // See 4.13 Pathname Resolution, IEEE Std 1003.1-2017
-    // https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13
-
-    use std::os::unix::prelude::OsStrExt;
-    let mut components = path.components();
-    let path_os = path.as_os_str().as_bytes();
-
-    let mut normalized = if path.is_absolute() {
-        // "If a pathname begins with two successive <slash> characters, the
-        // first component following the leading <slash> characters may be
-        // interpreted in an implementation-defined manner, although more than
-        // two leading <slash> characters shall be treated as a single <slash>
-        // character."
-        if path_os.starts_with(b"//") && !path_os.starts_with(b"///") {
-            components.next();
-            PathBuf::from("//")
-        } else {
-            PathBuf::new()
-        }
-    } else {
-        env::current_dir()?
-    };
-    normalized.extend(components);
-
-    // "Interfaces using pathname resolution may specify additional constraints
-    // when a pathname that does not name an existing directory contains at
-    // least one non- <slash> character and contains one or more trailing
-    // <slash> characters".
-    // A trailing <slash> is also meaningful if "a symbolic link is
-    // encountered during pathname resolution".
-
-    if path_os.ends_with(b"/") {
-        normalized.push("");
-    }
-
-    Ok(normalized)
-}
-
-#[cfg(windows)]
-fn absolute_windows(path: &std::path::Path) -> std::io::Result<std::path::PathBuf> {
-    use std::ffi::OsString;
-    use std::io::Error;
-    use std::os::windows::ffi::{OsStrExt, OsStringExt};
-    use std::ptr::null_mut;
-    #[link(name = "kernel32")]
-    extern "system" {
-        fn GetFullPathNameW(
-            lpFileName: *const u16,
-            nBufferLength: u32,
-            lpBuffer: *mut u16,
-            lpFilePart: *mut *const u16,
-        ) -> u32;
-    }
-
-    unsafe {
-        // encode the path as UTF-16
-        let path: Vec<u16> = path.as_os_str().encode_wide().chain([0]).collect();
-        let mut buffer = Vec::new();
-        // Loop until either success or failure.
-        loop {
-            // Try to get the absolute path
-            let len = GetFullPathNameW(
-                path.as_ptr(),
-                buffer.len().try_into().unwrap(),
-                buffer.as_mut_ptr(),
-                null_mut(),
-            );
-            match len as usize {
-                // Failure
-                0 => return Err(Error::last_os_error()),
-                // Buffer is too small, resize.
-                len if len > buffer.len() => buffer.resize(len, 0),
-                // Success!
-                len => {
-                    buffer.truncate(len);
-                    return Ok(OsString::from_wide(&buffer).into());
-                }
-            }
-        }
-    }
-}
-
 /// Adapted from <https://github.com/llvm/llvm-project/blob/782e91224601e461c019e0a4573bbccc6094fbcd/llvm/cmake/modules/HandleLLVMOptions.cmake#L1058-L1079>
 ///
 /// When `clang-cl` is used with instrumentation, we need to add clang's runtime library resource

src/bootstrap/src/utils/helpers/tests.rs

@@ -25,27 +25,6 @@ fn test_make() {
     }
 }
 
-#[cfg(unix)]
-#[test]
-fn test_absolute_unix() {
-    use crate::utils::helpers::absolute_unix;
-
-    // Test an absolute path
-    let path = PathBuf::from("/home/user/file.txt");
-    assert_eq!(absolute_unix(&path).unwrap(), PathBuf::from("/home/user/file.txt"));
-
-    // Test an absolute path with double leading slashes
-    let path = PathBuf::from("//root//file.txt");
-    assert_eq!(absolute_unix(&path).unwrap(), PathBuf::from("//root/file.txt"));
-
-    // Test a relative path
-    let path = PathBuf::from("relative/path");
-    assert_eq!(
-        absolute_unix(&path).unwrap(),
-        std::env::current_dir().unwrap().join("relative/path")
-    );
-}
-
 #[test]
 fn test_beta_rev_parsing() {
     // single digit revision