zigtools · SuperAuguste · Jul 8, 2022 · Jul 8, 2022 · Jul 8, 2022 · Jul 8, 2022
diff --git a/README.md b/README.md
@@ -9,15 +9,27 @@ Zig Language Server, or `zls`, is a language server for Zig. The Zig wiki states
 ## Table Of Contents
 
 - [Installation](#installation)
-  - [Build Options](#build-options)
+  - [Installing binaries](#installing-binaries)
+    - [MacOS](#macos)
+    - [Linux](#linux)
+  - [From Source](#from-source)
+    - [Build Options](#build-options)
+    - [Updating Data Files](#updating-data-files)
   - [Configuration Options](#configuration-options)
-- [Usage](#usage)
+- [Features](#features)
   - [VSCode](#vscode)
   - [Sublime Text](#sublime-text)
+    - [Sublime Text 3](#sublime-text-3)
+    - [Sublime Text 4](#sublime-text-4)
   - [Kate](#kate)
   - [Neovim/Vim8](#neovimvim8)
+    - [CoC](#coc)
+    - [YouCompleteMe](#youcompleteme)
+    - [nvim-lspconfig](#nvim-lspconfig)
+    - [LanguageClient-neovim](#languageclient-neovim)
   - [Emacs](#emacs)
   - [Doom Emacs](#doom-emacs)
+  - [Spacemacs](#spacemacs)
 - [Related Projects](#related-projects)
 - [License](#license)
 
@@ -88,6 +100,7 @@ The following options are currently available.
 | Option | Type | Default value | What it Does |
 | --- | --- | --- | --- |
 | `enable_snippets` | `bool` | `false` | Enables snippet completions when the client also supports them. |
+| `enable_unused_variable_warnings` | `bool` | `false`| Enables warnings for local variables that aren't used. |
 | `zig_lib_path` | `?[]const u8` | `null` | zig library path, e.g. `/path/to/zig/lib/zig`, used to analyze std library imports. |
 | `zig_exe_path` | `?[]const u8` | `null` | zig executable path, e.g. `/path/to/zig/zig`, used to run the custom build runner. If `null`, zig is looked up in `PATH`. Will be used to infer the zig standard library path if none is provided. |
 | `warn_style` | `bool` | `false` | Enables warnings for style *guideline* mismatches |
@@ -125,7 +138,7 @@ Install the `zls-vscode` extension from [here](https://github.com/zigtools/zls-v
 - Install the `LSP` package from [here](https://github.com/sublimelsp/LSP/releases) or via Package Control.
 - Add this snippet to `LSP's` user settings:
 
-#### For Sublime Text 3:
+#### Sublime Text 3
 
 ```json
 {
@@ -141,7 +154,7 @@ Install the `zls-vscode` extension from [here](https://github.com/zigtools/zls-v
 }
 ```
 
-#### For Sublime Text 4:
+#### Sublime Text 4
 
 ```json
 {

diff --git a/src/Config.zig b/src/Config.zig
@@ -3,6 +3,9 @@
 /// Whether to enable snippet completions
 enable_snippets: bool = false,
 
+/// Whether to enable unused variable warnings
+enable_unused_variable_warnings: bool = false,
+
 /// zig library path
 zig_lib_path: ?[]const u8 = null,
 

diff --git a/src/main.zig b/src/main.zig
@@ -229,11 +229,68 @@ fn publishDiagnostics(arena: *std.heap.ArenaAllocator, handle: DocumentStore.Han
         });
     }
 
+    if (config.enable_unused_variable_warnings) {
+        for (handle.document_scope.scopes) |scope| {
+            const scope_data = switch (scope.data) {
+                .function => |f| f,
+                .block => |b| b,
+                else => continue,
+            };
+
+            var decl_iterator = scope.decls.iterator();
+            while (decl_iterator.next()) |decl| {
+                var identifier_count: usize = 0;
+
+                var name_token_index = switch (decl.value_ptr.*) {
+                    .ast_node => |an| s: {
+                        const an_tag = tree.nodes.items(.tag)[an];
+                        switch (an_tag) {
+                            .simple_var_decl => {
+                                break :s tree.nodes.items(.main_token)[an] + 1;
+                            },
+                            else => continue,
+                        }
+                    },
+                    .param_decl => |param| param.name_token orelse continue,
+                    else => continue,
+                };
+
+                const pit_start = tree.firstToken(scope_data);
+                const pit_end = ast.lastToken(tree, scope_data);
+
+                for (tree.tokens.items(.tag)[pit_start..pit_end]) |tag, index| {
+                    if (tag == .identifier and std.mem.eql(u8, tree.tokenSlice(pit_start + @intCast(u32, index)), tree.tokenSlice(name_token_index))) identifier_count += 1;
+                }
+
+                if (identifier_count <= 1)
+                    try diagnostics.append(.{
+                        .range = astLocationToRange(tree.tokenLocation(0, name_token_index)),
+                        .severity = .Error,
+                        .code = "unused_variable",
+                        .source = "zls",
+                        .message = "Unused variable! Either remove the variable or use '_ = ' on the variable to bypass this error.",
+                    });
+            }
+        }
+    }
+
     // TODO: style warnings for types, values and declarations below root scope
     if (tree.errors.len == 0) {
         for (tree.rootDecls()) |decl_idx| {
             const decl = tree.nodes.items(.tag)[decl_idx];
             switch (decl) {
+                // .simple_var_decl => {
+                //     // var d = ast.varDecl(tree, decl_idx).?;
+                //     const loc = tree.tokenLocation(0, decl_idx);
+
+                // try diagnostics.append(.{
+                //     .range = astLocationToRange(loc),
+                //     .severity = .Information,
+                //     .code = "unused_variable",
+                //     .source = "zls",
+                //     .message = "Unused variable",
+                // });
+                // },
                 .fn_proto,
                 .fn_proto_multi,
                 .fn_proto_one,
@@ -255,15 +312,15 @@ fn publishDiagnostics(arena: *std.heap.ArenaAllocator, handle: DocumentStore.Han
                                 try diagnostics.append(.{
                                     .range = astLocationToRange(loc),
                                     .severity = .Information,
-                                    .code = "BadStyle",
+                                    .code = "bad-style",
                                     .source = "zls",
                                     .message = "Functions should be camelCase",
                                 });
                             } else if (is_type_function and !analysis.isPascalCase(func_name)) {
                                 try diagnostics.append(.{
                                     .range = astLocationToRange(loc),
                                     .severity = .Information,
-                                    .code = "BadStyle",
+                                    .code = "bad-style",
                                     .source = "zls",
                                     .message = "Type functions should be PascalCase",
                                 });
@@ -1192,7 +1249,7 @@ fn completeFieldAccess(arena: *std.heap.ArenaAllocator, id: types.RequestId, han
         truncateCompletions(completions.items, config.max_detail_length);
         if (client_capabilities.label_details_support) {
             for (completions.items) |*item| {
-               try formatDetailledLabel(item, arena.allocator());
+                try formatDetailledLabel(item, arena.allocator());
             }
         }
     }
@@ -1375,7 +1432,6 @@ fn formatDetailledLabel(item: *types.CompletionItem, alloc: std.mem.Allocator) !
     //     logger.info("labelDetails: {s}  ::  {s}", .{item.labelDetails.?.detail, item.labelDetails.?.description});
 }
 
-
 fn completeError(arena: *std.heap.ArenaAllocator, id: types.RequestId, handle: *DocumentStore.Handle, config: *const Config) !void {
     const tracy_zone = tracy.trace(@src());
     defer tracy_zone.end();
@@ -1396,36 +1452,35 @@ fn completeError(arena: *std.heap.ArenaAllocator, id: types.RequestId, handle: *
     });
 }
 
-fn kindToSortScore(kind: types.CompletionItem.Kind) [] const u8 {
-    return switch (kind)
-    {
+fn kindToSortScore(kind: types.CompletionItem.Kind) []const u8 {
+    return switch (kind) {
         .Constant => "1_",
 
         .Variable => "2_",
         .Field => "3_",
         .Function => "4_",
-
-        .Keyword,
-        .EnumMember => "5_",
-
+
+        .Keyword, .EnumMember => "5_",
+
         .Class,
         .Interface,
         .Struct,
         // Union?
-        .TypeParameter => "6_",
-
-        else => "9_"
+        .TypeParameter,
+        => "6_",
+
+        else => "9_",
     };
 }
 
 fn sortCompletionItems(completions: []types.CompletionItem, _: *const Config, alloc: std.mem.Allocator) void {
     // TODO: config for sorting rule?
     for (completions) |*c| {
         c.sortText = kindToSortScore(c.kind);
-        
+
         if (alloc.alloc(u8, 2 + c.label.len)) |it| {
             std.mem.copy(u8, it, c.sortText.?);
-            std.mem.copy(u8, it[2 .. ], c.label);
+            std.mem.copy(u8, it[2..], c.label);
             c.sortText = it;
         } else |_| {}
     }
@@ -1554,13 +1609,7 @@ fn initializeHandler(arena: *std.heap.ArenaAllocator, id: types.RequestId, req:
                     },
                     .textDocumentSync = .Full,
                     .renameProvider = true,
-                    .completionProvider = .{
-                        .resolveProvider = false,
-                        .triggerCharacters = &[_][]const u8{ ".", ":", "@" },
-                        .completionItem = .{
-                            .labelDetailsSupport = true
-                        }
-                    },
+                    .completionProvider = .{ .resolveProvider = false, .triggerCharacters = &[_][]const u8{ ".", ":", "@" }, .completionItem = .{ .labelDetailsSupport = true } },
                     .documentHighlightProvider = false,
                     .hoverProvider = true,
                     .codeActionProvider = false,

diff --git a/src/requests.zig b/src/requests.zig
@@ -263,6 +263,7 @@ pub const Configuration = struct {
     params: struct {
         settings: struct {
             enable_snippets: ?bool,
+            enable_unused_variable_warnings: ?bool,
             zig_lib_path: ?[]const u8,
             zig_exe_path: ?[]const u8,
             warn_style: ?bool,

diff --git a/src/types.zig b/src/types.zig
@@ -251,11 +251,11 @@ pub const CompletionItem = struct {
 
     insertTextFormat: ?InsertTextFormat = .PlainText,
     documentation: ?MarkupContent = null,
-    
+
     // FIXME: i commented this out, because otherwise the vscode client complains about *ranges*
     // and breaks code completion entirely
     // see: https://github.com/zigtools/zls-vscode/pull/33
-    // textEdit: ?TextEdit = null, 
+    // textEdit: ?TextEdit = null,
 };
 
 pub const CompletionItemLabelDetails = struct {

diff --git a/tests/sessions.zig b/tests/sessions.zig
@@ -186,7 +186,7 @@ test "Request completion with no trailing whitespace" {
     try server.request("textDocument/completion",
         \\{"textDocument":{"uri":"file:///test.zig"}, "position":{"line":1,"character":1}}
     ,
-         \\{"isIncomplete":false,"items":[{"label":"std","kind":21,"textEdit":null,"filterText":null,"insertText":"std","insertTextFormat":1,"detail":"const std = @import(\"std\")","documentation":null,"sortText":"1_std"}]}
+        \\{"isIncomplete":false,"items":[{"label":"std","labelDetails":{"detail":"","description":"@import(\"std\")","sortText":null},"kind":21,"detail":"std","sortText":"1_std","filterText":null,"insertText":"std","insertTextFormat":1,"documentation":null}]}
     );
 }
 
@@ -214,7 +214,7 @@ test "Self-referential definition" {
     try server.request("textDocument/completion",
         \\{"textDocument":{"uri":"file:///test.zig"}, "position":{"line":1,"character":1}}
     ,
-        \\{"isIncomplete":false,"items":[{"label":"h","kind":21,"textEdit":null,"filterText":null,"insertText":"h","insertTextFormat":1,"detail":"const h = h(0)","documentation":null}]}
+        \\{"isIncomplete":false,"items":[{"label":"h","labelDetails":{"detail":"","description":"h(0)","sortText":null},"kind":21,"detail":"h","sortText":"1_h","filterText":null,"insertText":"h","insertTextFormat":1,"documentation":null}]}
     );
 }
 
@@ -245,13 +245,13 @@ test "Pointer and optional deref" {
     try server.request("textDocument/completion",
         \\{"textDocument":{"uri":"file:///test.zig"}, "position":{"line":1,"character":18}}
     ,
-        \\{"isIncomplete":false,"items":[{"label":"data","kind":5,"textEdit":null,"filterText":null,"insertText":"data","insertTextFormat":1,"detail":"data: i32 = 5","documentation":null}]}
+        \\{"isIncomplete":false,"items":[{"label":"data","labelDetails":{"detail":"","description":"i32 ","sortText":null},"kind":5,"detail":"data","sortText":"3_data","filterText":null,"insertText":"data","insertTextFormat":1,"documentation":null}]}
     );
 }
 
 test "Request utf-8 offset encoding" {
     var server = try Server.start(initialize_msg_offs,
-        \\{"offsetEncoding":"utf-8","capabilities":{"signatureHelpProvider":{"triggerCharacters":["("],"retriggerCharacters":[","]},"textDocumentSync":1,"renameProvider":true,"completionProvider":{"resolveProvider":false,"triggerCharacters":[".",":","@"]},"documentHighlightProvider":false,"hoverProvider":true,"codeActionProvider":false,"declarationProvider":true,"definitionProvider":true,"typeDefinitionProvider":true,"implementationProvider":false,"referencesProvider":true,"documentSymbolProvider":true,"colorProvider":false,"documentFormattingProvider":true,"documentRangeFormattingProvider":false,"foldingRangeProvider":false,"selectionRangeProvider":false,"workspaceSymbolProvider":false,"rangeProvider":false,"documentProvider":true,"workspace":{"workspaceFolders":{"supported":false,"changeNotifications":false}},"semanticTokensProvider":{"full":true,"range":false,"legend":{"tokenTypes":["type","parameter","variable","enumMember","field","errorTag","function","keyword","comment","string","number","operator","builtin","label","keywordLiteral"],"tokenModifiers":["namespace","struct","enum","union","opaque","declaration","async","documentation","generic"]}}},"serverInfo":{"name":"zls","version":"0.1.0"}}
+        \\{"offsetEncoding":"utf-8","capabilities":{"signatureHelpProvider":{"triggerCharacters":["("],"retriggerCharacters":[","]},"textDocumentSync":1,"renameProvider":true,"completionProvider":{"resolveProvider":false,"triggerCharacters":[".",":","@"],"completionItem":{"labelDetailsSupport":true}},"documentHighlightProvider":false,"hoverProvider":true,"codeActionProvider":false,"declarationProvider":true,"definitionProvider":true,"typeDefinitionProvider":true,"implementationProvider":false,"referencesProvider":true,"documentSymbolProvider":true,"colorProvider":false,"documentFormattingProvider":true,"documentRangeFormattingProvider":false,"foldingRangeProvider":false,"selectionRangeProvider":false,"workspaceSymbolProvider":false,"rangeProvider":false,"documentProvider":true,"workspace":{"workspaceFolders":{"supported":false,"changeNotifications":false}},"semanticTokensProvider":{"full":true,"range":false,"legend":{"tokenTypes":["type","parameter","variable","enumMember","field","errorTag","function","keyword","comment","string","number","operator","builtin","label","keywordLiteral"],"tokenModifiers":["namespace","struct","enum","union","opaque","declaration","async","documentation","generic"]}}},"serverInfo":{"name":"zls","version":"0.1.0"}}
     );
     defer server.shutdown();
 }