1 files changed, 281 insertions, 125 deletions

diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index 182ed4c91..bd035ced9 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -5,16 +5,21 @@
 ///
 /// So, this modules should not be used during hir construction, it exists
 /// purely for "IDE needs".
+use std::sync::Arc;
+
+use rustc_hash::{FxHashSet, FxHashMap};
 use ra_db::{FileId, FilePosition};
 use ra_syntax::{
-    SyntaxNode,
+    SyntaxNode, AstPtr, TextUnit, SyntaxNodePtr, TextRange,
     ast::{self, AstNode, NameOwner},
-    algo::{find_node_at_offset, find_token_at_offset},
+    algo::find_node_at_offset,
+    SyntaxKind::*,
 };
 
 use crate::{
-    HirDatabase, Function, Struct, Enum,Const,Static,
+    HirDatabase, Function, Struct, Enum, Const, Static, Either, DefWithBody, PerNs, Name,
     AsName, Module, HirFileId, Crate, Trait, Resolver,
+    expr::{BodySourceMap, scope::{ScopeId, ExprScopes}},
     ids::LocationCtx,
     expr, AstId
 };
@@ -87,63 +92,6 @@ fn module_from_source(
     )
 }
 
-pub fn const_from_source(
-    db: &impl HirDatabase,
-    file_id: FileId,
-    const_def: &ast::ConstDef,
-) -> Option<Const> {
-    let module = module_from_child_node(db, file_id, const_def.syntax())?;
-    let res = const_from_module(db, module, const_def);
-    Some(res)
-}
-
-pub fn const_from_module(
-    db: &impl HirDatabase,
-    module: Module,
-    const_def: &ast::ConstDef,
-) -> Const {
-    let (file_id, _) = module.definition_source(db);
-    let file_id = file_id.into();
-    let ctx = LocationCtx::new(db, module, file_id);
-    Const { id: ctx.to_def(const_def) }
-}
-
-pub fn function_from_position(db: &impl HirDatabase, position: FilePosition) -> Option<Function> {
-    let file = db.parse(position.file_id);
-    let fn_def = find_node_at_offset::<ast::FnDef>(file.syntax(), position.offset)?;
-    function_from_source(db, position.file_id, fn_def)
-}
-
-pub fn function_from_source(
-    db: &impl HirDatabase,
-    file_id: FileId,
-    fn_def: &ast::FnDef,
-) -> Option<Function> {
-    let module = module_from_child_node(db, file_id, fn_def.syntax())?;
-    let res = function_from_module(db, module, fn_def);
-    Some(res)
-}
-
-pub fn function_from_module(
-    db: &impl HirDatabase,
-    module: Module,
-    fn_def: &ast::FnDef,
-) -> Function {
-    let (file_id, _) = module.definition_source(db);
-    let file_id = file_id.into();
-    let ctx = LocationCtx::new(db, module, file_id);
-    Function { id: ctx.to_def(fn_def) }
-}
-
-pub fn function_from_child_node(
-    db: &impl HirDatabase,
-    file_id: FileId,
-    node: &SyntaxNode,
-) -> Option<Function> {
-    let fn_def = node.ancestors().find_map(ast::FnDef::cast)?;
-    function_from_source(db, file_id, fn_def)
-}
-
 pub fn struct_from_module(
     db: &impl HirDatabase,
     module: Module,
@@ -155,27 +103,6 @@ pub fn struct_from_module(
     Struct { id: ctx.to_def(struct_def) }
 }
 
-pub fn static_from_source(
-    db: &impl HirDatabase,
-    file_id: FileId,
-    static_def: &ast::StaticDef,
-) -> Option<Static> {
-    let module = module_from_child_node(db, file_id, static_def.syntax())?;
-    let res = static_from_module(db, module, static_def);
-    Some(res)
-}
-
-pub fn static_from_module(
-    db: &impl HirDatabase,
-    module: Module,
-    static_def: &ast::StaticDef,
-) -> Static {
-    let (file_id, _) = module.definition_source(db);
-    let file_id = file_id.into();
-    let ctx = LocationCtx::new(db, module, file_id);
-    Static { id: ctx.to_def(static_def) }
-}
-
 pub fn enum_from_module(db: &impl HirDatabase, module: Module, enum_def: &ast::EnumDef) -> Enum {
     let (file_id, _) = module.definition_source(db);
     let file_id = file_id.into();
@@ -194,48 +121,6 @@ pub fn trait_from_module(
     Trait { id: ctx.to_def(trait_def) }
 }
 
-pub fn resolver_for_position(db: &impl HirDatabase, position: FilePosition) -> Resolver {
-    let file_id = position.file_id;
-    let file = db.parse(file_id);
-    find_token_at_offset(file.syntax(), position.offset)
-        .find_map(|token| {
-            token.parent().ancestors().find_map(|node| {
-                if ast::Expr::cast(node).is_some() || ast::Block::cast(node).is_some() {
-                    if let Some(func) = function_from_child_node(db, file_id, node) {
-                        let scopes = func.scopes(db);
-                        let scope = scopes.scope_for_offset(position.offset);
-                        Some(expr::resolver_for_scope(func.body(db), db, scope))
-                    } else {
-                        // FIXME const/static/array length
-                        None
-                    }
-                } else {
-                    try_get_resolver_for_node(db, file_id, node)
-                }
-            })
-        })
-        .unwrap_or_default()
-}
-
-pub fn resolver_for_node(db: &impl HirDatabase, file_id: FileId, node: &SyntaxNode) -> Resolver {
-    node.ancestors()
-        .find_map(|node| {
-            if ast::Expr::cast(node).is_some() || ast::Block::cast(node).is_some() {
-                if let Some(func) = function_from_child_node(db, file_id, node) {
-                    let scopes = func.scopes(db);
-                    let scope = scopes.scope_for(&node);
-                    Some(expr::resolver_for_scope(func.body(db), db, scope))
-                } else {
-                    // FIXME const/static/array length
-                    None
-                }
-            } else {
-                try_get_resolver_for_node(db, file_id, node)
-            }
-        })
-        .unwrap_or_default()
-}
-
 fn try_get_resolver_for_node(
     db: &impl HirDatabase,
     file_id: FileId,
@@ -251,10 +136,281 @@ fn try_get_resolver_for_node(
     } else if let Some(e) = ast::EnumDef::cast(node) {
         let module = module_from_child_node(db, file_id, e.syntax())?;
         Some(enum_from_module(db, module, e).resolver(db))
-    } else if let Some(f) = ast::FnDef::cast(node) {
-        function_from_source(db, file_id, f).map(|f| f.resolver(db))
+    } else if node.kind() == FN_DEF || node.kind() == CONST_DEF || node.kind() == STATIC_DEF {
+        Some(def_with_body_from_child_node(db, file_id, node)?.resolver(db))
     } else {
         // FIXME add missing cases
         None
     }
 }
+
+fn def_with_body_from_child_node(
+    db: &impl HirDatabase,
+    file_id: FileId,
+    node: &SyntaxNode,
+) -> Option<DefWithBody> {
+    let module = module_from_child_node(db, file_id, node)?;
+    let ctx = LocationCtx::new(db, module, file_id.into());
+    node.ancestors().find_map(|node| {
+        if let Some(def) = ast::FnDef::cast(node) {
+            return Some(Function { id: ctx.to_def(def) }.into());
+        }
+        if let Some(def) = ast::ConstDef::cast(node) {
+            return Some(Const { id: ctx.to_def(def) }.into());
+        }
+        if let Some(def) = ast::StaticDef::cast(node) {
+            return Some(Static { id: ctx.to_def(def) }.into());
+        }
+        None
+    })
+}
+
+/// `SourceAnalyzer` is a convenience wrapper which exposes HIR API in terms of
+/// original source files. It should not be used inside the HIR itself.
+#[derive(Debug)]
+pub struct SourceAnalyzer {
+    resolver: Resolver,
+    body_source_map: Option<Arc<BodySourceMap>>,
+    infer: Option<Arc<crate::ty::InferenceResult>>,
+    scopes: Option<Arc<crate::expr::ExprScopes>>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum PathResolution {
+    /// An item
+    Def(crate::ModuleDef),
+    /// A local binding (only value namespace)
+    LocalBinding(Either<AstPtr<ast::Pat>, AstPtr<ast::SelfParam>>),
+    /// A generic parameter
+    GenericParam(u32),
+    SelfType(crate::ImplBlock),
+    AssocItem(crate::ImplItem),
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct ScopeEntryWithSyntax {
+    pub(crate) name: Name,
+    pub(crate) ptr: Either<AstPtr<ast::Pat>, AstPtr<ast::SelfParam>>,
+}
+
+impl ScopeEntryWithSyntax {
+    pub fn name(&self) -> &Name {
+        &self.name
+    }
+
+    pub fn ptr(&self) -> Either<AstPtr<ast::Pat>, AstPtr<ast::SelfParam>> {
+        self.ptr
+    }
+}
+
+#[derive(Debug)]
+pub struct ReferenceDescriptor {
+    pub range: TextRange,
+    pub name: String,
+}
+
+impl SourceAnalyzer {
+    pub fn new(
+        db: &impl HirDatabase,
+        file_id: FileId,
+        node: &SyntaxNode,
+        offset: Option<TextUnit>,
+    ) -> SourceAnalyzer {
+        let def_with_body = def_with_body_from_child_node(db, file_id, node);
+        if let Some(def) = def_with_body {
+            let source_map = def.body_source_map(db);
+            let scopes = db.expr_scopes(def);
+            let scope = match offset {
+                None => scope_for(&scopes, &source_map, &node),
+                Some(offset) => scope_for_offset(&scopes, &source_map, offset),
+            };
+            let resolver = expr::resolver_for_scope(def.body(db), db, scope);
+            SourceAnalyzer {
+                resolver,
+                body_source_map: Some(source_map),
+                infer: Some(def.infer(db)),
+                scopes: Some(scopes),
+            }
+        } else {
+            SourceAnalyzer {
+                resolver: node
+                    .ancestors()
+                    .find_map(|node| try_get_resolver_for_node(db, file_id, node))
+                    .unwrap_or_default(),
+                body_source_map: None,
+                infer: None,
+                scopes: None,
+            }
+        }
+    }
+
+    pub fn type_of(&self, _db: &impl HirDatabase, expr: &ast::Expr) -> Option<crate::Ty> {
+        let expr_id = self.body_source_map.as_ref()?.node_expr(expr)?;
+        Some(self.infer.as_ref()?[expr_id].clone())
+    }
+
+    pub fn type_of_pat(&self, _db: &impl HirDatabase, pat: &ast::Pat) -> Option<crate::Ty> {
+        let pat_id = self.body_source_map.as_ref()?.node_pat(pat)?;
+        Some(self.infer.as_ref()?[pat_id].clone())
+    }
+
+    pub fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
+        let expr_id = self.body_source_map.as_ref()?.node_expr(call.into())?;
+        self.infer.as_ref()?.method_resolution(expr_id)
+    }
+
+    pub fn resolve_field(&self, field: &ast::FieldExpr) -> Option<crate::StructField> {
+        let expr_id = self.body_source_map.as_ref()?.node_expr(field.into())?;
+        self.infer.as_ref()?.field_resolution(expr_id)
+    }
+
+    pub fn resolve_hir_path(
+        &self,
+        db: &impl HirDatabase,
+        path: &crate::Path,
+    ) -> PerNs<crate::Resolution> {
+        self.resolver.resolve_path(db, path)
+    }
+
+    pub fn resolve_path(&self, db: &impl HirDatabase, path: &ast::Path) -> Option<PathResolution> {
+        if let Some(path_expr) = path.syntax().parent().and_then(ast::PathExpr::cast) {
+            let expr_id = self.body_source_map.as_ref()?.node_expr(path_expr.into())?;
+            if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_expr(expr_id) {
+                return Some(PathResolution::AssocItem(assoc));
+            }
+        }
+        if let Some(path_pat) = path.syntax().parent().and_then(ast::PathPat::cast) {
+            let pat_id = self.body_source_map.as_ref()?.node_pat(path_pat.into())?;
+            if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_pat(pat_id) {
+                return Some(PathResolution::AssocItem(assoc));
+            }
+        }
+        let hir_path = crate::Path::from_ast(path)?;
+        let res = self.resolver.resolve_path(db, &hir_path);
+        let res = res.clone().take_types().or_else(|| res.take_values())?;
+        let res = match res {
+            crate::Resolution::Def(it) => PathResolution::Def(it),
+            crate::Resolution::LocalBinding(it) => {
+                PathResolution::LocalBinding(self.body_source_map.as_ref()?.pat_syntax(it)?)
+            }
+            crate::Resolution::GenericParam(it) => PathResolution::GenericParam(it),
+            crate::Resolution::SelfType(it) => PathResolution::SelfType(it),
+        };
+        Some(res)
+    }
+
+    pub fn resolve_local_name(&self, name_ref: &ast::NameRef) -> Option<ScopeEntryWithSyntax> {
+        let mut shadowed = FxHashSet::default();
+        let name = name_ref.as_name();
+        let source_map = self.body_source_map.as_ref()?;
+        let scopes = self.scopes.as_ref()?;
+        let scope = scope_for(scopes, source_map, name_ref.syntax());
+        let ret = scopes
+            .scope_chain(scope)
+            .flat_map(|scope| scopes.entries(scope).iter())
+            .filter(|entry| shadowed.insert(entry.name()))
+            .filter(|entry| entry.name() == &name)
+            .nth(0);
+        ret.and_then(|entry| {
+            Some(ScopeEntryWithSyntax {
+                name: entry.name().clone(),
+                ptr: source_map.pat_syntax(entry.pat())?,
+            })
+        })
+    }
+
+    pub fn all_names(&self, db: &impl HirDatabase) -> FxHashMap<Name, PerNs<crate::Resolution>> {
+        self.resolver.all_names(db)
+    }
+
+    pub fn find_all_refs(&self, pat: &ast::BindPat) -> Vec<ReferenceDescriptor> {
+        // FIXME: at least, this should work with any DefWithBody, but ideally
+        // this should be hir-based altogether
+        let fn_def = pat.syntax().ancestors().find_map(ast::FnDef::cast).unwrap();
+        let ptr = Either::A(AstPtr::new(pat.into()));
+        fn_def
+            .syntax()
+            .descendants()
+            .filter_map(ast::NameRef::cast)
+            .filter(|name_ref| match self.resolve_local_name(*name_ref) {
+                None => false,
+                Some(entry) => entry.ptr() == ptr,
+            })
+            .map(|name_ref| ReferenceDescriptor {
+                name: name_ref.text().to_string(),
+                range: name_ref.syntax().range(),
+            })
+            .collect()
+    }
+
+    #[cfg(test)]
+    pub(crate) fn body_source_map(&self) -> Arc<BodySourceMap> {
+        self.body_source_map.clone().unwrap()
+    }
+
+    #[cfg(test)]
+    pub(crate) fn inference_result(&self) -> Arc<crate::ty::InferenceResult> {
+        self.infer.clone().unwrap()
+    }
+
+    #[cfg(test)]
+    pub(crate) fn scopes(&self) -> Arc<ExprScopes> {
+        self.scopes.clone().unwrap()
+    }
+}
+
+fn scope_for(
+    scopes: &ExprScopes,
+    source_map: &BodySourceMap,
+    node: &SyntaxNode,
+) -> Option<ScopeId> {
+    node.ancestors()
+        .map(SyntaxNodePtr::new)
+        .filter_map(|ptr| source_map.syntax_expr(ptr))
+        .find_map(|it| scopes.scope_for(it))
+}
+
+fn scope_for_offset(
+    scopes: &ExprScopes,
+    source_map: &BodySourceMap,
+    offset: TextUnit,
+) -> Option<ScopeId> {
+    scopes
+        .scope_by_expr()
+        .iter()
+        .filter_map(|(id, scope)| Some((source_map.expr_syntax(*id)?, scope)))
+        // find containing scope
+        .min_by_key(|(ptr, _scope)| {
+            (!(ptr.range().start() <= offset && offset <= ptr.range().end()), ptr.range().len())
+        })
+        .map(|(ptr, scope)| adjust(scopes, source_map, ptr, offset).unwrap_or(*scope))
+}
+
+// XXX: during completion, cursor might be outside of any particular
+// expression. Try to figure out the correct scope...
+fn adjust(
+    scopes: &ExprScopes,
+    source_map: &BodySourceMap,
+    ptr: SyntaxNodePtr,
+    offset: TextUnit,
+) -> Option<ScopeId> {
+    let r = ptr.range();
+    let child_scopes = scopes
+        .scope_by_expr()
+        .iter()
+        .filter_map(|(id, scope)| Some((source_map.expr_syntax(*id)?, scope)))
+        .map(|(ptr, scope)| (ptr.range(), scope))
+        .filter(|(range, _)| range.start() <= offset && range.is_subrange(&r) && *range != r);
+
+    child_scopes
+        .max_by(|(r1, _), (r2, _)| {
+            if r2.is_subrange(&r1) {
+                std::cmp::Ordering::Greater
+            } else if r1.is_subrange(&r2) {
+                std::cmp::Ordering::Less
+            } else {
+                r1.start().cmp(&r2.start())
+            }
+        })
+        .map(|(_ptr, scope)| *scope)
+}