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Mercurial > core / rust/lib/util/src/bs/git.rs

changeset 698: 96958d3eb5b0
parent: 0ccbbd142694
author: Richard Westhaver <ellis@rwest.io>
date: Fri, 04 Oct 2024 22:04:59 -0400
permissions: -rw-r--r--
description: fixes 
     1 use std::{env, fs, fs::File, io, io::Read, path::PathBuf};
     2 /// Make sure the calling `build.rs` script is rerun when `.git/HEAD` or the ref
     3 /// of `.git/HEAD` changed.
     4 ///
     5 /// The file is searched from the `CARGO_MANIFEST_DIR` upwards. If the file can
     6 /// not be found, a warning is generated.
     7 pub fn rerun_if_git_head_changed() {
     8   let mut manifest_dir = PathBuf::from(
     9     env::var("CARGO_MANIFEST_DIR")
    10       .expect("`CARGO_MANIFEST_DIR` is always set by cargo."),
    11   );
    12   let manifest_dir_copy = manifest_dir.clone();
    13 
    14   while manifest_dir.parent().is_some() {
    15     match get_git_paths(&manifest_dir) {
    16       Err(err) => {
    17         eprintln!("cargo:warning=Unable to read the Git repository: {}", err);
    18 
    19         return;
    20       }
    21       Ok(None) => {}
    22       Ok(Some(paths)) => {
    23         for p in paths {
    24           println!("cargo:rerun-if-changed={}", p.display());
    25         }
    26 
    27         return;
    28       }
    29     }
    30 
    31     manifest_dir.pop();
    32   }
    33 
    34   println!(
    35     "cargo:warning=Could not find `.git/HEAD` searching from `{}` upwards!",
    36     manifest_dir_copy.display(),
    37   );
    38 }
    39 
    40 // Code taken from https://github.com/rustyhorde/vergen/blob/8d522db8c8e16e26c0fc9ea8e6b0247cbf5cca84/src/output/envvar.rs
    41 fn get_git_paths(path: &PathBuf) -> Result<Option<Vec<PathBuf>>, io::Error> {
    42   let git_dir_or_file = path.join(".git");
    43 
    44   if let Ok(metadata) = fs::metadata(&git_dir_or_file) {
    45     if metadata.is_dir() {
    46       // Echo the HEAD path
    47       let git_head_path = git_dir_or_file.join("HEAD");
    48 
    49       // Determine where HEAD points and echo that path also.
    50       let mut f = File::open(&git_head_path)?;
    51       let mut git_head_contents = String::new();
    52       let _ = f.read_to_string(&mut git_head_contents)?;
    53       let ref_vec: Vec<&str> = git_head_contents.split(": ").collect();
    54 
    55       if ref_vec.len() == 2 {
    56         let current_head_file = ref_vec[1];
    57         let git_refs_path = git_dir_or_file.join(current_head_file);
    58 
    59         Ok(Some(vec![git_head_path, git_refs_path]))
    60       } else {
    61         Err(io::Error::new(
    62           io::ErrorKind::Other,
    63           "You are most likely in a detached HEAD state",
    64         ))
    65       }
    66     } else if metadata.is_file() {
    67       // We are in a worktree, so find out where the actual
    68       // worktrees/<name>/HEAD file is.
    69       let mut git_file = File::open(&git_dir_or_file)?;
    70       let mut git_contents = String::new();
    71       let _ = git_file.read_to_string(&mut git_contents)?;
    72       let dir_vec: Vec<&str> = git_contents.split(": ").collect();
    73       let git_path = dir_vec[1].trim();
    74 
    75       // Echo the HEAD psth
    76       let git_head_path = PathBuf::from(git_path).join("HEAD");
    77 
    78       // Find out what the full path to the .git dir is.
    79       let mut actual_git_dir = PathBuf::from(git_path);
    80       actual_git_dir.pop();
    81       actual_git_dir.pop();
    82 
    83       // Determine where HEAD points and echo that path also.
    84       let mut f = File::open(&git_head_path)?;
    85       let mut git_head_contents = String::new();
    86       let _ = f.read_to_string(&mut git_head_contents)?;
    87       let ref_vec: Vec<&str> = git_head_contents.split(": ").collect();
    88 
    89       if ref_vec.len() == 2 {
    90         let current_head_file = ref_vec[1];
    91         let git_refs_path = actual_git_dir.join(current_head_file);
    92 
    93         Ok(Some(vec![git_head_path, git_refs_path]))
    94       } else {
    95         Err(io::Error::new(
    96           io::ErrorKind::Other,
    97           "You are most likely in a detached HEAD state",
    98         ))
    99       }
   100     } else {
   101       Err(io::Error::new(
   102         io::ErrorKind::Other,
   103         "Invalid .git format (Not a directory or a file)",
   104       ))
   105     }
   106   } else {
   107     Ok(None)
   108   }
   109 }