Merge #774

774: Batch crate & command r=matklad a=flodiebold

This adds a new crate, `ra_batch`, which is intended for scenarios where you're loading a workspace once and then running some analyses using the HIR API. Also, it adds a command to `ra_cli` which uses that to type-check all crates in a workspace and print some statistics:

E.g. in rust-analyzer:
```
> $ time target/release/ra_cli analysis-stats
Database loaded, 21 roots
Crates in this dir: 28
Total modules found: 231
Total declarations: 3694
Total functions: 2408
Total expressions: 47017
Expressions of unknown type: 19826 (42%)
Expressions of partially unknown type: 4482 (9%)
target/release/ra_cli analysis-stats  3,23s user 0,60s system 100% cpu 3,821 total
```

Or in rust-lang/rust:
```
> $ time ../opensource/rust-analyzer/target/release/ra_cli analysis-stats
Database loaded, 77 roots
Crates in this dir: 130
Total modules found: 1820
Total declarations: 35038
Total functions: 25914
Total expressions: 753678
Expressions of unknown type: 337975 (44%)
Expressions of partially unknown type: 92314 (12%)
../opensource/rust-analyzer/target/release/ra_cli analysis-stats  13,45s user 2,08s system 100% cpu 15,477 total
```

~This still needs a test. Type-checking all of rust-analyzer sadly takes almost a minute when compiled in debug mode :sweat_smile: So I'll need to add something simpler (maybe just looking at a few modules).~

Co-authored-by: Florian Diebold <[email protected]>

3 files changed, 92 insertions, 3 deletions

diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index cafc5279d..19f103855 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -1,7 +1,7 @@
 use std::sync::Arc;
 
 use relative_path::RelativePathBuf;
-use ra_db::{CrateId, FileId};
+use ra_db::{CrateId, FileId, SourceRootId};
 use ra_syntax::{ast::self, TreeArc, SyntaxNode};
 
 use crate::{
@@ -16,7 +16,7 @@ use crate::{
     docs::{Documentation, Docs, docs_from_ast},
     module_tree::ModuleId,
     ids::{FunctionId, StructId, EnumId, AstItemDef, ConstId, StaticId, TraitId, TypeId},
-    impl_block::ImplId,
+    impl_block::{ImplId, ImplBlock},
     resolve::Resolver,
 };
 
@@ -44,6 +44,15 @@ impl Crate {
     pub fn root_module(&self, db: &impl PersistentHirDatabase) -> Option<Module> {
         self.root_module_impl(db)
     }
+
+    // TODO: should this be in source_binder?
+    pub fn source_root_crates(
+        db: &impl PersistentHirDatabase,
+        source_root: SourceRootId,
+    ) -> Vec<Crate> {
+        let crate_ids = db.source_root_crates(source_root);
+        crate_ids.iter().map(|&crate_id| Crate { crate_id }).collect()
+    }
 }
 
 #[derive(Debug)]
@@ -168,6 +177,27 @@ impl Module {
         let item_map = db.item_map(self.krate);
         Resolver::default().push_module_scope(item_map, *self)
     }
+
+    pub fn declarations(self, db: &impl HirDatabase) -> Vec<ModuleDef> {
+        let (lowered_module, _) = db.lower_module(self);
+        lowered_module
+            .declarations
+            .values()
+            .cloned()
+            .flat_map(|per_ns| {
+                per_ns.take_types().into_iter().chain(per_ns.take_values().into_iter())
+            })
+            .collect()
+    }
+
+    pub fn impl_blocks(self, db: &impl HirDatabase) -> Vec<ImplBlock> {
+        let module_impl_blocks = db.impls_in_module(self);
+        module_impl_blocks
+            .impls
+            .iter()
+            .map(|(impl_id, _)| ImplBlock::from_id(module_impl_blocks.clone(), impl_id))
+            .collect()
+    }
 }
 
 impl Docs for Module {
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index b30e11abb..4e73590d0 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -70,6 +70,14 @@ impl Body {
         self.owner
     }
 
+    pub fn exprs(&self) -> impl Iterator<Item = (ExprId, &Expr)> {
+        self.exprs.iter()
+    }
+
+    pub fn pats(&self) -> impl Iterator<Item = (PatId, &Pat)> {
+        self.pats.iter()
+    }
+
     pub fn syntax_mapping(&self, db: &impl HirDatabase) -> Arc<BodySyntaxMapping> {
         db.body_syntax_mapping(self.owner)
     }
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index 7203a8a10..2dc1de41a 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -449,6 +449,49 @@ impl Ty {
         Ty::Tuple(Arc::new([]))
     }
 
+    pub fn walk(&self, f: &mut impl FnMut(&Ty)) {
+        f(self);
+        match self {
+            Ty::Slice(t) | Ty::Array(t) => t.walk(f),
+            Ty::RawPtr(t, _) => t.walk(f),
+            Ty::Ref(t, _) => t.walk(f),
+            Ty::Tuple(ts) => {
+                for t in ts.iter() {
+                    t.walk(f);
+                }
+            }
+            Ty::FnPtr(sig) => {
+                for input in &sig.input {
+                    input.walk(f);
+                }
+                sig.output.walk(f);
+            }
+            Ty::FnDef { substs, sig, .. } => {
+                for input in &sig.input {
+                    input.walk(f);
+                }
+                sig.output.walk(f);
+                for t in substs.0.iter() {
+                    t.walk(f);
+                }
+            }
+            Ty::Adt { substs, .. } => {
+                for t in substs.0.iter() {
+                    t.walk(f);
+                }
+            }
+            Ty::Bool
+            | Ty::Char
+            | Ty::Int(_)
+            | Ty::Float(_)
+            | Ty::Str
+            | Ty::Never
+            | Ty::Param { .. }
+            | Ty::Infer(_)
+            | Ty::Unknown => {}
+        }
+    }
+
     fn walk_mut(&mut self, f: &mut impl FnMut(&mut Ty)) {
         f(self);
         match self {
@@ -491,7 +534,15 @@ impl Ty {
                 }
                 substs.0 = v.into();
             }
-            _ => {}
+            Ty::Bool
+            | Ty::Char
+            | Ty::Int(_)
+            | Ty::Float(_)
+            | Ty::Str
+            | Ty::Never
+            | Ty::Param { .. }
+            | Ty::Infer(_)
+            | Ty::Unknown => {}
         }
     }