Update cargo-xbuild to new rust directory layout (#87)

Author: phil-opp

README.md

@@ -81,7 +81,7 @@ In addition to the above configuration keys, `cargo-xbuild` can be also configur
 If you want to use a local Rust source instead of `rust-src` rustup component, you can set the `XARGO_RUST_SRC` environment variable.
 
 ```
-# The source of the `core` crate must be in `$XARGO_RUST_SRC/libcore`
+# The source of the `core` crate must be in `$XARGO_RUST_SRC/core`
 $ export XARGO_RUST_SRC=/path/to/rust/src
 
 $ cargo xbuild --target msp430-none-elf.json

src/rustc.rs

@@ -1,5 +1,4 @@
 use std::env;
-use std::ffi::OsStr;
 use std::hash::{Hash, Hasher};
 use std::path::{Path, PathBuf};
 use std::process::Command;
@@ -8,7 +7,6 @@ pub use rustc_version::version_meta as version;
 
 use serde_json;
 use serde_json::Value;
-use walkdir::WalkDir;
 
 use errors::*;
 use extensions::CommandExt;
@@ -65,38 +63,17 @@ impl Sysroot {
         &self.path
     }
 
-    /// Returns the path to Rust source, `$SRC`, where `$SRC/libstd/Carg.toml`
+    /// Returns the path to Rust source, `$SRC`, where `$SRC/std/Cargo.toml`
     /// exists
     pub fn src(&self) -> Result<Src> {
         let src = self.path().join("lib").join("rustlib").join("src");
 
-        if src.join("rust/src/libstd/Cargo.toml").is_file() {
+        if src.join("rust/library/std/Cargo.toml").is_file() {
             return Ok(Src {
-                path: src.join("rust/src"),
+                path: src.join("rust/library"),
             });
         }
 
-        if src.exists() {
-            for e in WalkDir::new(src) {
-                let e = e.chain_err(|| "couldn't walk the sysroot")?;
-
-                // Looking for $SRC/libstd/Cargo.toml
-                if e.file_type().is_file() && e.file_name() == "Cargo.toml" {
-                    let toml = e.path();
-
-                    if let Some(std) = toml.parent() {
-                        if let Some(src) = std.parent() {
-                            if std.file_name() == Some(OsStr::new("libstd")) {
-                                return Ok(Src {
-                                    path: src.to_owned(),
-                                });
-                            }
-                        }
-                    }
-                }
-            }
-        }
-
         Err("`rust-src` component not found. Run `rustup component add \
              rust-src`.")?
     }

src/sysroot.rs

@@ -177,7 +177,7 @@ version = "0.1.0"
     stoml.push_str("[dependencies.core]\n");
     stoml.push_str(&format!(
         "path = '{}'\n",
-        src.path().join("libcore").display()
+        src.path().join("core").display()
     ));
 
     if config.panic_immediate_abort {
@@ -187,10 +187,10 @@ version = "0.1.0"
     stoml.push_str("[patch.crates-io.rustc-std-workspace-core]\n");
     stoml.push_str(&format!(
         "path = '{}'\n",
-        src.path().join("tools/rustc-std-workspace-core").display()
+        src.path().join("rustc-std-workspace-core").display()
     ));
 
-    let path = src.path().join("liballoc/lib.rs").display().to_string();
+    let path = src.path().join("alloc/src/lib.rs").display().to_string();
     let mut map = Table::new();
     let mut lib = Table::new();
     lib.insert("name".to_owned(), Value::String("alloc".to_owned()));