From 406f366ccc8b903f457cc694dc1214794c0cfc88 Mon Sep 17 00:00:00 2001
From: "Jeremy A. Kolb" <jkolb@ara.com>
Date: Wed, 24 Oct 2018 14:24:32 -0400
Subject: [PATCH] Add DeclarationDescriptor and ReferenceDescriptor

Fixes #142
Fixes #146
---
 crates/ra_analysis/src/descriptors/mod.rs | 57 +++++++++++++++++++++--
 crates/ra_analysis/src/imp.rs             | 13 +++++-
 crates/ra_analysis/tests/tests.rs         | 11 +++++
 3 files changed, 77 insertions(+), 4 deletions(-)

diff --git a/crates/ra_analysis/src/descriptors/mod.rs b/crates/ra_analysis/src/descriptors/mod.rs
index 0c4991757d..e27f8314ad 100644
--- a/crates/ra_analysis/src/descriptors/mod.rs
+++ b/crates/ra_analysis/src/descriptors/mod.rs
@@ -5,16 +5,17 @@ use std::sync::Arc;
 
 use ra_syntax::{
     SmolStr,
-    ast::{FnDefNode},
+    ast::{self, AstNode, FnDefNode},
+    TextRange
 };
 
 use crate::{
     FileId, Cancelable,
     db::SyntaxDatabase,
     descriptors::module::{ModuleTree, ModuleId, ModuleScope},
-    descriptors::function::{FnId, FnScopes},
+    descriptors::function::{FnId, FnScopes, resolve_local_name},
     input::SourceRootId,
-    syntax_ptr::SyntaxPtrDatabase,
+    syntax_ptr::{SyntaxPtrDatabase, LocalSyntaxPtr},
 };
 
 
@@ -44,3 +45,53 @@ salsa::query_group! {
         }
     }
 }
+
+#[derive(Debug)]
+pub struct ReferenceDescriptor {
+    pub range: TextRange,
+    pub name: String
+}
+
+#[derive(Debug)]
+pub struct DeclarationDescriptor<'a> {
+    pat: ast::BindPat<'a>,
+    pub range: TextRange
+}
+
+impl<'a> DeclarationDescriptor<'a> {
+    pub fn new(pat: ast::BindPat) -> DeclarationDescriptor {
+        let range = pat.syntax().range();
+
+        DeclarationDescriptor {
+            pat,
+            range
+        }
+    }
+
+    pub fn find_all_refs(&self) -> Vec<ReferenceDescriptor> {
+        let name_ptr = LocalSyntaxPtr::new(self.pat.syntax());
+
+        let fn_def = match self.pat.syntax().ancestors().find_map(ast::FnDef::cast) {
+            Some(def) => def,
+            None => return Default::default()
+        };
+
+        let fn_scopes = FnScopes::new(fn_def);
+
+        let refs : Vec<_> = fn_def.syntax().descendants()
+            .filter_map(ast::NameRef::cast)
+            .filter(|name_ref| {
+                match resolve_local_name(*name_ref, &fn_scopes) {
+                    None => false,
+                    Some(entry) => entry.ptr() == name_ptr,
+                }
+            })
+            .map(|name_ref| ReferenceDescriptor {
+                name: name_ref.syntax().text().to_string(),
+                range : name_ref.syntax().range(),
+            })
+            .collect();
+
+        refs
+    }
+}
diff --git a/crates/ra_analysis/src/imp.rs b/crates/ra_analysis/src/imp.rs
index b3c094041c..f950a79957 100644
--- a/crates/ra_analysis/src/imp.rs
+++ b/crates/ra_analysis/src/imp.rs
@@ -22,7 +22,7 @@ use crate::{
     },
     input::{SourceRootId, FilesDatabase, SourceRoot, WORKSPACE},
     descriptors::{
-        DescriptorDatabase,
+        DescriptorDatabase, DeclarationDescriptor,
         module::{ModuleTree, Problem},
         function::{FnDescriptor, FnId},
     },
@@ -327,6 +327,17 @@ impl AnalysisImpl {
 
         let mut ret = vec![];
 
+        if let Some(binding) = find_node_at_offset::<ast::BindPat>(syntax, offset) {
+            let decl = DeclarationDescriptor::new(binding);
+
+            ret.push((file_id, decl.range));
+
+            ret.extend(decl.find_all_refs().into_iter()
+                .map(|ref_desc| (file_id, ref_desc.range )));
+
+            return ret;
+        }
+
         // Find the symbol we are looking for
         if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(syntax, offset) {
 
diff --git a/crates/ra_analysis/tests/tests.rs b/crates/ra_analysis/tests/tests.rs
index 9e2478d9e8..22d27cdbe8 100644
--- a/crates/ra_analysis/tests/tests.rs
+++ b/crates/ra_analysis/tests/tests.rs
@@ -377,6 +377,17 @@ fn test_find_all_refs_for_param_inside() {
     assert_eq!(refs.len(), 2);
 }
 
+#[test]
+fn test_find_all_refs_for_fn_param() {
+    let code = r#"
+    fn foo(i<|> : u32) -> u32 {
+        i
+    }"#;
+
+    let refs = get_all_refs(code);
+    assert_eq!(refs.len(), 2);
+}
+
 #[test]
 fn test_complete_crate_path() {
     let (analysis, position) = analysis_and_position("