Factor out BinDir code into llvm-tools crate

Author: phil-opp

Cargo.lock

@@ -22,6 +22,9 @@ version = "0.2.4"
 default-features = false
 features = ["unicode"]
 
+[build-dependencies]
+llvm-tools = "0.1"
+
 [features]
 default = []
 vga_320x200 = []

Cargo.toml

@@ -24,11 +24,22 @@ fn main() {
     let kernel_out_path = out_dir.join(format!("kernel_bin-{}.o", kernel_file_name));
     let kernel_archive_path = out_dir.join(format!("libkernel_bin-{}.a", kernel_file_name));
 
+    let llvm_tools = match llvm_tools::LlvmTools::new() {
+        Ok(tools) => tools,
+        Err(llvm_tools::Error::NotFound) => {
+            eprintln!("Error: llvm-tools not found");
+            eprintln!("Maybe the rustup component `llvm-tools-preview` is missing?");
+            eprintln!("  Install it through: `rustup component add llvm-tools-preview`");
+            process::exit(1);
+        }
+        Err(err) => {
+            eprintln!("Failed to retrieve llvm-tools component: {:?}", err);
+            process::exit(1);
+        }
+    };
+    let objcopy = llvm_tools.tool(&llvm_tools::exe("llvm-objcopy")).expect("llvm-objcopy not found in llvm-tools");
 
-    let bin_dir = BinDir::new();
-    let objcopy = bin_dir.tool(&LlvmTool::tool_name("objcopy")).expect("llvm-objcopy not found in llvm-tools");
-
-    let mut cmd = Command::new(objcopy.path());
+    let mut cmd = Command::new(objcopy);
     cmd.arg("-I").arg("binary");
     cmd.arg("-O").arg("elf64-x86-64");
     cmd.arg("--binary-architecture=i386:x86-64");
@@ -45,8 +56,13 @@ fn main() {
         process::exit(1);
     }
 
-    let ar = bin_dir.tool(&LlvmTool::tool_name("ar")).expect("llvm-ar not found in llvm-tools");
-    let mut cmd = Command::new(ar.path());
+    let ar = llvm_tools.tool(&llvm_tools::exe("llvm-ar")).unwrap_or_else(|| {
+        eprintln!("Failed to retrieve llvm-ar component");
+        eprint!("This component is available since nightly-XXXX-XX-XX,");
+        eprintln!("so try updating your toolchain if you're using an older nightly");
+        process::exit(1);
+    });
+    let mut cmd = Command::new(ar);
     cmd.arg("crs");
     cmd.arg(&kernel_archive_path);
     cmd.arg(&kernel_out_path);
@@ -61,75 +77,3 @@ fn main() {
     println!("cargo:rustc-link-search=native={}", out_dir.display());
     println!("cargo:rustc-link-lib=static=kernel_bin-{}", kernel_file_name);
 }
-
-#[derive(Debug)]
-struct BinDir {
-    bin_dir: PathBuf,
-}
-
-impl BinDir {
-    fn new() -> Self {
-        let example_tool_name = LlvmTool::tool_name("objdump");
-        let output = Command::new("rustc")
-            .arg("--print")
-            .arg("sysroot")
-            .output()
-            .expect("failed to print sysroot");
-        if !output.status.success() {
-            eprintln!("Failed to execute `rustc --print sysroot`");
-            eprintln!("Stderr: {}", String::from_utf8(output.stderr).expect("error not valid unicode"));
-            process::exit(1);
-        }
-
-        let sysroot = PathBuf::from(String::from_utf8(output.stdout).expect("sysroot not valid unicode").trim());
-
-        let rustlib = sysroot.join("lib").join("rustlib");
-        for entry in rustlib.read_dir().expect("read_dir on sysroot dir failed") {
-            let bin_dir = entry.expect("failed to read sysroot dir entry").path().join("bin");
-            let tool_path = bin_dir.join(&example_tool_name);
-            if tool_path.exists() {
-                return Self { bin_dir };
-            }
-        }
-
-        eprintln!("Error: llvm-tools not found");
-        eprintln!("Maybe the rustup component `llvm-tools-preview` is missing?");
-        eprintln!("  Install it through: `rustup component add llvm-tools-preview`");
-        process::exit(1);
-    }
-
-    fn tool(&self, tool_name: &str) -> Option<LlvmTool> {
-        let tool_path = self.bin_dir.join(&tool_name);
-        
-        if tool_path.exists() {
-            Some(LlvmTool {
-                name: tool_name.to_owned(),
-                path: tool_path,
-            })
-        } else {
-            None
-        }
-    }
-}
-
-#[derive(Debug)]
-struct LlvmTool {
-    name: String,
-    path: PathBuf,
-}
-
-impl LlvmTool {
-    fn path(&self) -> &Path {
-        &self.path
-    }
-
-    #[cfg(target_os = "windows")]
-    fn tool_name(tool: &str) -> String {
-        format!("llvm-{}.exe", tool)
-    }
-
-    #[cfg(not(target_os = "windows"))]
-    fn tool_name(tool: &str) -> String {
-        format!("llvm-{}", tool)
-    }
-}