1 files changed, 31 insertions, 0 deletions
diff --git a/src/tools/error_index_generator/build.rs b/src/tools/error_index_generator/build.rs
new file mode 100644
index 000000000..70b00b36c
--- /dev/null
+++ b/src/tools/error_index_generator/build.rs
@@ -0,0 +1,31 @@
+use std::path::PathBuf;
+use std::{env, fs};
+use walkdir::WalkDir;
+
+fn main() {
+    // The src directory (we are in src/tools/error_index_generator)
+    // Note that we could skip one of the .. but this ensures we at least loosely find the right
+    // directory.
+    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
+
+    let error_codes_path = "../../../compiler/rustc_error_codes/src/error_codes.rs";
+
+    println!("cargo:rerun-if-changed={}", error_codes_path);
+    let file = fs::read_to_string(error_codes_path)
+        .unwrap()
+        .replace(": include_str!(\"./error_codes/", ": include_str!(\"./");
+    let contents = format!("(|| {{\n{}\n}})()", file);
+    fs::write(&out_dir.join("all_error_codes.rs"), &contents).unwrap();
+
+    // We copy the md files as well to the target directory.
+    for entry in WalkDir::new("../../../compiler/rustc_error_codes/src/error_codes") {
+        let entry = entry.unwrap();
+        match entry.path().extension() {
+            Some(s) if s == "md" => {}
+            _ => continue,
+        }
+        println!("cargo:rerun-if-changed={}", entry.path().to_str().unwrap());
+        let md_content = fs::read_to_string(entry.path()).unwrap();
+        fs::write(&out_dir.join(entry.file_name()), &md_content).unwrap();
+    }
+}