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Diffstat (limited to 'crates/ra_env/src/lib.rs')
-rw-r--r-- | crates/ra_env/src/lib.rs | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/crates/ra_env/src/lib.rs b/crates/ra_env/src/lib.rs new file mode 100644 index 000000000..413da1982 --- /dev/null +++ b/crates/ra_env/src/lib.rs | |||
@@ -0,0 +1,66 @@ | |||
1 | //! This crate contains a single public function | ||
2 | //! [`get_path_for_executable`](fn.get_path_for_executable.html). | ||
3 | //! See docs there for more information. | ||
4 | |||
5 | use anyhow::{bail, Result}; | ||
6 | use std::env; | ||
7 | use std::path::{Path, PathBuf}; | ||
8 | use std::process::Command; | ||
9 | |||
10 | /// Return a `PathBuf` to use for the given executable. | ||
11 | /// | ||
12 | /// E.g., `get_path_for_executable("cargo")` may return just `cargo` if that | ||
13 | /// gives a valid Cargo executable; or it may return a full path to a valid | ||
14 | /// Cargo. | ||
15 | pub fn get_path_for_executable(executable_name: impl AsRef<str>) -> Result<PathBuf> { | ||
16 | // The current implementation checks three places for an executable to use: | ||
17 | // 1) Appropriate environment variable (erroring if this is set but not a usable executable) | ||
18 | // example: for cargo, this checks $CARGO environment variable; for rustc, $RUSTC; etc | ||
19 | // 2) `<executable_name>` | ||
20 | // example: for cargo, this tries just `cargo`, which will succeed if `cargo` is on the $PATH | ||
21 | // 3) `~/.cargo/bin/<executable_name>` | ||
22 | // example: for cargo, this tries ~/.cargo/bin/cargo | ||
23 | // It seems that this is a reasonable place to try for cargo, rustc, and rustup | ||
24 | let executable_name = executable_name.as_ref(); | ||
25 | let env_var = executable_name.to_ascii_uppercase(); | ||
26 | if let Ok(path) = env::var(&env_var) { | ||
27 | if is_valid_executable(&path) { | ||
28 | Ok(path.into()) | ||
29 | } else { | ||
30 | bail!( | ||
31 | "`{}` environment variable points to something that's not a valid executable", | ||
32 | env_var | ||
33 | ) | ||
34 | } | ||
35 | } else { | ||
36 | if is_valid_executable(executable_name) { | ||
37 | return Ok(executable_name.into()); | ||
38 | } | ||
39 | if let Some(mut path) = ::home::home_dir() { | ||
40 | path.push(".cargo"); | ||
41 | path.push("bin"); | ||
42 | path.push(executable_name); | ||
43 | if is_valid_executable(&path) { | ||
44 | return Ok(path); | ||
45 | } | ||
46 | } | ||
47 | // This error message may also be caused by $PATH or $CARGO/$RUSTC/etc not being set correctly | ||
48 | // for VSCode, even if they are set correctly in a terminal. | ||
49 | // On macOS in particular, launching VSCode from terminal with `code <dirname>` causes VSCode | ||
50 | // to inherit environment variables including $PATH, $CARGO, $RUSTC, etc from that terminal; | ||
51 | // but launching VSCode from Dock does not inherit environment variables from a terminal. | ||
52 | // For more discussion, see #3118. | ||
53 | bail!( | ||
54 | "Failed to find `{}` executable. Make sure `{}` is in `$PATH`, or set `${}` to point to a valid executable.", | ||
55 | executable_name, executable_name, env_var | ||
56 | ) | ||
57 | } | ||
58 | } | ||
59 | |||
60 | /// Does the given `Path` point to a usable executable? | ||
61 | /// | ||
62 | /// (assumes the executable takes a `--version` switch and writes to stdout, | ||
63 | /// which is true for `cargo`, `rustc`, and `rustup`) | ||
64 | fn is_valid_executable(p: impl AsRef<Path>) -> bool { | ||
65 | Command::new(p.as_ref()).arg("--version").output().is_ok() | ||
66 | } | ||