Add an ra_cli command that analyses all crates in the current workspace

... and prints various stats about how many expressions have a type etc.

crates/ra_cli/src/analysis_stats.rs

@@ -0,0 +1,100 @@
+use std::collections::HashSet;
+
+use ra_db::SourceDatabase;
+use ra_batch::BatchDatabase;
+use ra_hir::{Crate, ModuleDef, Ty, ImplItem};
+use ra_syntax::AstNode;
+
+use crate::Result;
+
+pub fn run(verbose: bool) -> Result<()> {
+    let (db, roots) = BatchDatabase::load_cargo(".")?;
+    println!("Database loaded, {} roots", roots.len());
+    let mut num_crates = 0;
+    let mut visited_modules = HashSet::new();
+    let mut visit_queue = Vec::new();
+    for root in roots {
+        for krate in Crate::source_root_crates(&db, root) {
+            num_crates += 1;
+            let module = krate.root_module(&db).expect("crate in source root without root module");
+            visit_queue.push(module);
+        }
+    }
+    println!("Crates in this dir: {}", num_crates);
+    let mut num_decls = 0;
+    let mut funcs = Vec::new();
+    while let Some(module) = visit_queue.pop() {
+        if visited_modules.insert(module) {
+            visit_queue.extend(module.children(&db));
+
+            for decl in module.declarations(&db) {
+                num_decls += 1;
+                match decl {
+                    ModuleDef::Function(f) => funcs.push(f),
+                    _ => {}
+                }
+            }
+
+            for impl_block in module.impl_blocks(&db) {
+                for item in impl_block.items() {
+                    num_decls += 1;
+                    match item {
+                        ImplItem::Method(f) => funcs.push(*f),
+                        _ => {}
+                    }
+                }
+            }
+        }
+    }
+    println!("Total modules found: {}", visited_modules.len());
+    println!("Total declarations: {}", num_decls);
+    println!("Total functions: {}", funcs.len());
+    let bar = indicatif::ProgressBar::new(funcs.len() as u64);
+    bar.tick();
+    let mut num_exprs = 0;
+    let mut num_exprs_unknown = 0;
+    let mut num_exprs_partially_unknown = 0;
+    for f in funcs {
+        if verbose {
+            let (file_id, source) = f.source(&db);
+            let original_file = file_id.original_file(&db);
+            let path = db.file_relative_path(original_file);
+            let syntax_range = source.syntax().range();
+            let name = f.name(&db);
+            println!("{} ({:?} {})", name, path, syntax_range);
+        }
+        let body = f.body(&db);
+        let inference_result = f.infer(&db);
+        for (expr_id, _) in body.exprs() {
+            let ty = &inference_result[expr_id];
+            num_exprs += 1;
+            if let Ty::Unknown = ty {
+                num_exprs_unknown += 1;
+            } else {
+                let mut is_partially_unknown = false;
+                ty.walk(&mut |ty| {
+                    if let Ty::Unknown = ty {
+                        is_partially_unknown = true;
+                    }
+                });
+                if is_partially_unknown {
+                    num_exprs_partially_unknown += 1;
+                }
+            }
+        }
+        bar.inc(1);
+    }
+    bar.finish_and_clear();
+    println!("Total expressions: {}", num_exprs);
+    println!(
+        "Expressions of unknown type: {} ({}%)",
+        num_exprs_unknown,
+        (num_exprs_unknown * 100 / num_exprs)
+    );
+    println!(
+        "Expressions of partially unknown type: {} ({}%)",
+        num_exprs_partially_unknown,
+        (num_exprs_partially_unknown * 100 / num_exprs)
+    );
+    Ok(())
+}