Merge #5120

5120: Add a simple SSR subcommand to the rust-analyzer command line binary r=davidlattimore a=davidlattimore

Is adding the dependency on ra_ide_db OK? It's needed for the call to `db.local_roots()`

Co-authored-by: David Lattimore <dml@google.com>

crates/rust-analyzer/src/cli/ssr.rs

@@ -0,0 +1,33 @@
+//! Applies structured search replace rules from the command line.
+
+use crate::cli::{load_cargo::load_cargo, Result};
+use ra_ide::SourceFileEdit;
+use ra_ssr::{MatchFinder, SsrRule};
+
+pub fn apply_ssr_rules(rules: Vec<SsrRule>) -> Result<()> {
+    use ra_db::SourceDatabaseExt;
+    use ra_ide_db::symbol_index::SymbolsDatabase;
+    let (host, vfs) = load_cargo(&std::env::current_dir()?, true, true)?;
+    let db = host.raw_database();
+    let mut match_finder = MatchFinder::new(db);
+    for rule in rules {
+        match_finder.add_rule(rule);
+    }
+    let mut edits = Vec::new();
+    for &root in db.local_roots().iter() {
+        let sr = db.source_root(root);
+        for file_id in sr.iter() {
+            if let Some(edit) = match_finder.edits_for_file(file_id) {
+                edits.push(SourceFileEdit { file_id, edit });
+            }
+        }
+    }
+    for edit in edits {
+        if let Some(path) = vfs.file_path(edit.file_id).as_path() {
+            let mut contents = db.file_text(edit.file_id).to_string();
+            edit.edit.apply(&mut contents);
+            std::fs::write(path, contents)?;
+        }
+    }
+    Ok(())
+}