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.

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),
     }