Add new LSP extension for workspace symbol lookup

The new extension allows filtering of workspace symbool lookup
results by search scope or search kind.

Filtering can be configured in 3 different ways:

 - The '#' or '*' markers can be added inline with the symbol lookup
   query.

   The '#' marker means symbols should be looked up in the current
   workspace and any dependencies. If not specified, only current
   workspace is considered.

   The '*' marker means all kinds of symbols should be looked up
   (types, functions, etc). If not specified, only type symbols are
   returned.

 - Each LSP request can take an optional search_scope or search_kind
   argument query parameter.

 - Finally there are 2 global config options that can be set for all
   requests served by the active RA instance.

Add support for setting the global config options to the VSCode
extension.
The extension does not use the per-request way, but it's useful for
other IDEs.

The latest version of VSCode filters out the inline markers, so
currently the only reasonable way to use the new functionality is
via the global config.

5 files changed, 153 insertions, 7 deletions

diff --git a/crates/ide_db/src/symbol_index.rs b/crates/ide_db/src/symbol_index.rs
index da427d686..0f5c4abc4 100644
--- a/crates/ide_db/src/symbol_index.rs
+++ b/crates/ide_db/src/symbol_index.rs
@@ -161,6 +161,11 @@ impl<DB: ParallelDatabase> Clone for Snap<salsa::Snapshot<DB>> {
 // That is, `#` switches from "types" to all symbols, `*` switches from the current
 // workspace to dependencies.
 //
+// Note that filtering does not currently work in VSCode due to the editor never
+// sending the special symbols to the language server. Instead, you can configure
+// the filtering via the `rust-analyzer.workspace.symbol.search.scope` and
+// `rust-analyzer.workspace.symbol.search.kind` settings.
+//
 // |===
 // | Editor  | Shortcut
 //
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index a3866c1ba..339014fd3 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -24,7 +24,8 @@ use vfs::AbsPathBuf;
 
 use crate::{
     caps::completion_item_edit_resolve, diagnostics::DiagnosticsMapConfig,
-    line_index::OffsetEncoding, lsp_ext::supports_utf8,
+    line_index::OffsetEncoding, lsp_ext::supports_utf8, lsp_ext::WorkspaceSymbolSearchKind,
+    lsp_ext::WorkspaceSymbolSearchScope,
 };
 
 // Defines the server-side configuration of the rust-analyzer. We generate
@@ -215,6 +216,11 @@ config_data! {
         /// Advanced option, fully override the command rust-analyzer uses for
         /// formatting.
         rustfmt_overrideCommand: Option<Vec<String>> = "null",
+
+        /// Workspace symbol search scope.
+        workspace_symbol_search_scope: WorskpaceSymbolSearchScopeDef = "\"workspace\"",
+        /// Workspace symbol search kind.
+        workspace_symbol_search_kind: WorskpaceSymbolSearchKindDef = "\"only_types\"",
     }
 }
 
@@ -309,6 +315,15 @@ pub struct RunnablesConfig {
     pub cargo_extra_args: Vec<String>,
 }
 
+/// Configuration for workspace symbol search requests.
+#[derive(Debug, Clone)]
+pub struct WorkspaceSymbolConfig {
+    /// In what scope should the symbol be searched in.
+    pub search_scope: WorkspaceSymbolSearchScope,
+    /// What kind of symbol is being search for.
+    pub search_kind: WorkspaceSymbolSearchKind,
+}
+
 impl Config {
     pub fn new(root_path: AbsPathBuf, caps: ClientCapabilities) -> Self {
         Config { caps, data: ConfigData::default(), discovered_projects: None, root_path }
@@ -687,6 +702,22 @@ impl Config {
             .contains(&MarkupKind::Markdown),
         }
     }
+
+    pub fn workspace_symbol(&self) -> WorkspaceSymbolConfig {
+        WorkspaceSymbolConfig {
+            search_scope: match self.data.workspace_symbol_search_scope {
+                WorskpaceSymbolSearchScopeDef::Workspace => WorkspaceSymbolSearchScope::Workspace,
+                WorskpaceSymbolSearchScopeDef::WorkspaceAndDependencies => {
+                    WorkspaceSymbolSearchScope::WorkspaceAndDependencies
+                }
+            },
+            search_kind: match self.data.workspace_symbol_search_kind {
+                WorskpaceSymbolSearchKindDef::OnlyTypes => WorkspaceSymbolSearchKind::OnlyTypes,
+                WorskpaceSymbolSearchKindDef::AllSymbols => WorkspaceSymbolSearchKind::AllSymbols,
+            },
+        }
+    }
+
     pub fn semantic_tokens_refresh(&self) -> bool {
         try_or!(self.caps.workspace.as_ref()?.semantic_tokens.as_ref()?.refresh_support?, false)
     }
@@ -733,6 +764,20 @@ enum ImportPrefixDef {
     ByCrate,
 }
 
+#[derive(Deserialize, Debug, Clone)]
+#[serde(rename_all = "snake_case")]
+enum WorskpaceSymbolSearchScopeDef {
+    Workspace,
+    WorkspaceAndDependencies,
+}
+
+#[derive(Deserialize, Debug, Clone)]
+#[serde(rename_all = "snake_case")]
+enum WorskpaceSymbolSearchKindDef {
+    OnlyTypes,
+    AllSymbols,
+}
+
 macro_rules! _config_data {
     (struct $name:ident {
         $(
@@ -903,6 +948,22 @@ fn field_props(field: &str, ty: &str, doc: &[&str], default: &str) -> serde_json
             "type": "array",
             "items": { "type": ["string", "object"] },
         },
+        "WorskpaceSymbolSearchScopeDef" => set! {
+            "type": "string",
+            "enum": ["workspace", "workspace_and_dependencies"],
+            "enumDescriptions": [
+                "Search in current workspace only",
+                "Search in current workspace and dependencies"
+            ],
+        },
+        "WorskpaceSymbolSearchKindDef" => set! {
+            "type": "string",
+            "enum": ["only_types", "all_symbols"],
+            "enumDescriptions": [
+                "Search for types only",
+                "Search for all symbols kinds"
+            ],
+        },
         _ => panic!("{}: {}", ty, default),
     }
 
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index 8fe97fd7c..51041d7a0 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -38,7 +38,7 @@ use crate::{
     from_proto,
     global_state::{GlobalState, GlobalStateSnapshot},
     line_index::LineEndings,
-    lsp_ext::{self, InlayHint, InlayHintsParams},
+    lsp_ext::{self, InlayHint, InlayHintsParams, WorkspaceSymbolParams},
     lsp_utils::all_edits_are_disjoint,
     to_proto, LspError, Result,
 };
@@ -380,11 +380,12 @@ pub(crate) fn handle_document_symbol(
 
 pub(crate) fn handle_workspace_symbol(
     snap: GlobalStateSnapshot,
-    params: lsp_types::WorkspaceSymbolParams,
+    params: WorkspaceSymbolParams,
 ) -> Result<Option<Vec<SymbolInformation>>> {
     let _p = profile::span("handle_workspace_symbol");
-    let all_symbols = params.query.contains('#');
-    let libs = params.query.contains('*');
+
+    let (all_symbols, libs) = decide_search_scope_and_kind(&params, &snap);
+
     let query = {
         let query: String = params.query.chars().filter(|&c| c != '#' && c != '*').collect();
         let mut q = Query::new(query);
@@ -406,6 +407,45 @@ pub(crate) fn handle_workspace_symbol(
 
     return Ok(Some(res));
 
+    fn decide_search_scope_and_kind(
+        params: &WorkspaceSymbolParams,
+        snap: &GlobalStateSnapshot,
+    ) -> (bool, bool) {
+        // Support old-style parsing of markers in the query.
+        let mut all_symbols = params.query.contains('#');
+        let mut libs = params.query.contains('*');
+
+        let config = snap.config.workspace_symbol();
+
+        // If no explicit marker was set, check request params. If that's also empty
+        // use global config.
+        if !all_symbols {
+            let search_kind = if let Some(ref search_kind) = params.search_kind {
+                search_kind
+            } else {
+                &config.search_kind
+            };
+            all_symbols = match search_kind {
+                lsp_ext::WorkspaceSymbolSearchKind::OnlyTypes => false,
+                lsp_ext::WorkspaceSymbolSearchKind::AllSymbols => true,
+            }
+        }
+
+        if !libs {
+            let search_scope = if let Some(ref search_scope) = params.search_scope {
+                search_scope
+            } else {
+                &config.search_scope
+            };
+            libs = match search_scope {
+                lsp_ext::WorkspaceSymbolSearchScope::Workspace => false,
+                lsp_ext::WorkspaceSymbolSearchScope::WorkspaceAndDependencies => true,
+            }
+        }
+
+        (all_symbols, libs)
+    }
+
     fn exec_query(snap: &GlobalStateSnapshot, query: Query) -> Result<Vec<SymbolInformation>> {
         let mut res = Vec::new();
         for nav in snap.analysis.symbol_search(query)? {
diff --git a/crates/rust-analyzer/src/lsp_ext.rs b/crates/rust-analyzer/src/lsp_ext.rs
index 3bd098058..34b53a7a8 100644
--- a/crates/rust-analyzer/src/lsp_ext.rs
+++ b/crates/rust-analyzer/src/lsp_ext.rs
@@ -4,7 +4,8 @@ use std::{collections::HashMap, path::PathBuf};
 
 use lsp_types::request::Request;
 use lsp_types::{
-    notification::Notification, CodeActionKind, Position, Range, TextDocumentIdentifier,
+    notification::Notification, CodeActionKind, PartialResultParams, Position, Range,
+    TextDocumentIdentifier, WorkDoneProgressParams,
 };
 use serde::{Deserialize, Serialize};
 
@@ -438,3 +439,42 @@ pub enum MoveItemDirection {
     Up,
     Down,
 }
+
+#[derive(Debug)]
+pub enum WorkspaceSymbol {}
+
+impl Request for WorkspaceSymbol {
+    type Params = WorkspaceSymbolParams;
+    type Result = Option<Vec<lsp_types::SymbolInformation>>;
+    const METHOD: &'static str = "workspace/symbol";
+}
+
+#[derive(Debug, Eq, PartialEq, Clone, Default, Deserialize, Serialize)]
+pub struct WorkspaceSymbolParams {
+    #[serde(flatten)]
+    pub partial_result_params: PartialResultParams,
+
+    #[serde(flatten)]
+    pub work_done_progress_params: WorkDoneProgressParams,
+
+    /// A non-empty query string
+    pub query: String,
+
+    pub search_scope: Option<WorkspaceSymbolSearchScope>,
+
+    pub search_kind: Option<WorkspaceSymbolSearchKind>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, Eq, PartialEq)]
+#[serde(rename_all = "camelCase")]
+pub enum WorkspaceSymbolSearchScope {
+    Workspace,
+    WorkspaceAndDependencies,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, Eq, PartialEq)]
+#[serde(rename_all = "camelCase")]
+pub enum WorkspaceSymbolSearchKind {
+    OnlyTypes,
+    AllSymbols,
+}
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index c7bd7eee1..4e0791611 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -525,9 +525,9 @@ impl GlobalState {
             .on::<lsp_ext::ExternalDocs>(handlers::handle_open_docs)
             .on::<lsp_ext::OpenCargoToml>(handlers::handle_open_cargo_toml)
             .on::<lsp_ext::MoveItem>(handlers::handle_move_item)
+            .on::<lsp_ext::WorkspaceSymbol>(handlers::handle_workspace_symbol)
             .on::<lsp_types::request::OnTypeFormatting>(handlers::handle_on_type_formatting)
             .on::<lsp_types::request::DocumentSymbolRequest>(handlers::handle_document_symbol)
-            .on::<lsp_types::request::WorkspaceSymbol>(handlers::handle_workspace_symbol)
             .on::<lsp_types::request::GotoDefinition>(handlers::handle_goto_definition)
             .on::<lsp_types::request::GotoImplementation>(handlers::handle_goto_implementation)
             .on::<lsp_types::request::GotoTypeDefinition>(handlers::handle_goto_type_definition)