Add replace-version-placeholder tool

This tool is to be ran at specific points in the release process to replace
the version place holder made by stabilizations with the version number.

2 files changed, 40 insertions, 0 deletions

diff --git a/src/tools/replace-version-placeholder/Cargo.toml b/src/tools/replace-version-placeholder/Cargo.toml
new file mode 100644
index 00000000000..346ce6bd1db
--- /dev/null
+++ b/src/tools/replace-version-placeholder/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "replace-version-placeholder"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+tidy = { path = "../tidy" }
+walkdir = "2"
diff --git a/src/tools/replace-version-placeholder/src/main.rs b/src/tools/replace-version-placeholder/src/main.rs
new file mode 100644
index 00000000000..146e53f2e9a
--- /dev/null
+++ b/src/tools/replace-version-placeholder/src/main.rs
@@ -0,0 +1,30 @@
+use std::path::PathBuf;
+use tidy::{t, walk};
+
+pub const VERSION_PLACEHOLDER: &str = "CURRENT_RUSTC_VERSION";
+
+fn main() {
+    let root_path: PathBuf = std::env::args_os().nth(1).expect("need path to root of repo").into();
+    let version_path = root_path.join("src").join("version");
+    let version_str = t!(std::fs::read_to_string(&version_path), version_path);
+    let version_str = version_str.trim();
+    walk::walk(
+        &root_path,
+        &mut |path| {
+            walk::filter_dirs(path)
+                // We exempt these as they require the placeholder
+                // for their operation
+                || path.ends_with("compiler/rustc_passes/src/lib_features.rs")
+                || path.ends_with("src/tools/tidy/src/features/version.rs")
+                || path.ends_with("src/tools/replace-version-placeholder")
+        },
+        &mut |entry, contents| {
+            if !contents.contains(VERSION_PLACEHOLDER) {
+                return;
+            }
+            let new_contents = contents.replace(VERSION_PLACEHOLDER, version_str);
+            let path = entry.path();
+            t!(std::fs::write(&path, new_contents), path);
+        },
+    );
+}