Add preferences to handle clang-tidy functionality when clangd v9+ is…

… used.

Fixes issue #4579
This is a new linter for C/C++. There are two ways to initiate the linter:
  - From the preferences
  - Adding a new file located in the same folder of the files or a parent folder: .clang-tidy

Signed-off-by: Jacques Bouthillier <jacques.bouthillier@ericsson.com>

CHANGELOG.md

@@ -1,15 +1,19 @@
 # Change Log
 
 ## v0.5.0
+
+- [cpp] added new clang-tidy and clang-tidy-checks preferences to lint cpp program when clangd v9+ is used.
 - [plugin] `workspace.openTextDocument` API now respects the contributed `FileSystemProviders`
 
 Breaking changes:
+
 - [editor] computation of resource context keys moved to core [#4531](https://github.com/theia-ide/theia/pull/4531)
 - [plugin] support multiple windows per a backend [#4509](https://github.com/theia-ide/theia/issues/4509)
   - Some plugin bindings are scoped per a connection now. Clients, who contribute/rebind these bindings, will need to scope them per a connection as well.
 - [quick-open] disable separate fuzzy matching by default [#4549](https://github.com/theia-ide/theia/pull/4549)
 
 ## v0.4.0
+
 - [application-manager] added support for pre-load HTML templates
 - [console] added support for console `when` contexts
 - [core] added support for os `when` contexts
@@ -86,6 +90,7 @@ Breaking changes:
 
 
 Breaking changes:
+
 - menus aligned with built-in VS Code menus [#4173](https://github.com/theia-ide/theia/pull/4173)
   - navigator context menu group changes:
     - `1_open` and `4_new` replaced by `navigation` group
@@ -123,6 +128,7 @@ Breaking changes:
 
 
 ## v0.3.19
+
 - [core] added `hostname` alias
 - [core] added new `editor.formatOnSave` preference, to format documents on manual save
 - [core] added support for setting end of line character
@@ -164,6 +170,7 @@ Breaking changes:
 
 
 ## v0.3.18
+
 - [core] added a preference to define how to handle application exit
 - [core] added a way to prevent application exit from extensions
 - [core] added functionality to prevent application exit if some editors are dirty
@@ -203,6 +210,7 @@ Breaking changes:
 
 
 ## v0.3.17
+
 - Added better widget error handling for different use cases (ex: no workspace present, no repository present, ...)
 - Addressed multiple backend memory leaks
 - Prefixed quick-open commands for easier categorization and searching
@@ -241,6 +249,7 @@ Breaking changes:
 
 
 ## v0.3.16
+
 - Reverted [cpp] Add debugging for C/C++ programs. This feature will come back in its own cpp-specific repo
 - [callhierarchy][typescript] adapt to hierarchical document symbols
 - [core] added methods to un-register menus, commands and keybindings
@@ -254,6 +263,7 @@ Breaking changes:
 
 
 ## v0.3.15
+
 - [cpp] added debugging for C/C++ programs
 - [debug] added debug toolbar
 - [debug] resolved variables in configurations
@@ -265,6 +275,7 @@ Breaking changes:
 
 
 ## v0.3.13
+
 - Re-implemented additional widgets using React
 - Re-implemented miscellaneous components using React
 - [cpp] added a status bar button to select an active cpp build configuration
@@ -280,6 +291,7 @@ Breaking changes:
 
 
 ## v0.3.12
+
 - New Plugin system !
     - See [design](https://github.com/theia-ide/theia/issues/1482) and [documentation](https://github.com/theia-ide/theia/blob/master/packages/plugin/API.md) for more details.
 - Introducing [Task API](https://github.com/theia-ide/theia/pull/2086).
@@ -299,6 +311,7 @@ Breaking changes:
 - `HTML` files now open in the editor by default
 
 ## v0.3.11
+
 - Added search and replace widget
 - Added the ability to delete files on OSX with cmd+backspace
 - Added the ability to set more finely grained logger levels

packages/cpp/README.md

@@ -79,6 +79,30 @@ To get this working, you need to enable clangd's global index using the
             "cpp.clangdArgs": "--background-index"
         }
 
+## Using the clang-tidy linter
+
+Note: This functionality is available when using clangd 9 and later.
+
+You can set the preference 'cpp.clangTidy' to enable the clang-tidy linter included in clangd. When the preference is set, there are two ways to chose which of its built-in checks clang-tidy will use:
+
+- using the preferences:  'cpp.clangTidyChecks'
+- using the file '.clang-tidy' . The file is located in the same folder of the files or a parent folder.
+
+Note: using the preference checks will supersede the value found in the .clang-tidy file.
+
+The syntax used to fill the checks can be found at http://clang.llvm.org/extra/clang-tidy/
+
+clang-tidy has its own checks and can also run Clang static analyzer checks. Each check has a name ([see link above for full list](http://clang.llvm.org/extra/clang-tidy/)). Clang-tidy takes as input the checks that should run, in the form of a comma-separated list of positive and negative (prefixed with -) globs. Positive globs add subsets of checks, negative globs remove them.
+
+There are two ways to configure clang-tidy's checks: through a Theia preference or using a .clang-tidy config file. Here are examples for both:"
+
+    - for the preferences: "cpp.clangTidyChecks": "*,-readability-*"
+        - Meaning: enables all list-checks and disable all readability-* checks
+
+    - for the .clang-tidy file: Checks: -*,readability-*
+        - Meaning: disable all list-checks and enable all readability-* checks
+
 ## License
+
 - [Eclipse Public License 2.0](http://www.eclipse.org/legal/epl-2.0/)
 - [一 (Secondary) GNU General Public License, version 2 with the GNU Classpath Exception](https://projects.eclipse.org/license/secondary-gpl-2.0-cp)

packages/cpp/src/browser/cpp-language-client-contribution.ts

@@ -140,7 +140,9 @@ export class CppLanguageClientContribution extends BaseLanguageClientContributio
     protected getStartParameters(): CppStartParameters {
         return {
             clangdExecutable: this.cppPreferences['cpp.clangdExecutable'],
-            clangdArgs: this.cppPreferences['cpp.clangdArgs']
+            clangdArgs: this.cppPreferences['cpp.clangdArgs'],
+            clangTidy: this.cppPreferences['cpp.clangTidy'],
+            clangTidyChecks: this.cppPreferences['cpp.clangTidyChecks']
         };
     }
 }

packages/cpp/src/browser/cpp-preferences.ts

@@ -61,6 +61,16 @@ export const cppPreferencesSchema: PreferenceSchema = {
             description: 'Specify the arguments to pass to clangd when starting the language server.',
             default: '',
             type: 'string'
+        },
+        'cpp.clangTidy': {
+            description: 'Enable/disable C/C++ linting.',
+            default: false,
+            type: 'boolean'
+        },
+        'cpp.clangTidyChecks': {
+            description: 'Specify comma separated arguments to pass to clang-tidy. Activated only if cpp.clang-tidy is enabled',
+            default: '',
+            type: 'string'
         }
     }
 };
@@ -70,6 +80,8 @@ export class CppConfiguration {
     'cpp.experimentalCommands': boolean;
     'cpp.clangdExecutable': string;
     'cpp.clangdArgs': string;
+    'cpp.clangTidy': boolean;
+    'cpp.clangTidyChecks': string;
 }
 
 export const CppPreferences = Symbol('CppPreferences');

packages/cpp/src/common/index.ts

@@ -27,4 +27,6 @@ export const CLANGD_EXECUTABLE_DEFAULT = 'clangd';
 export interface CppStartParameters {
     clangdExecutable: string;
     clangdArgs: string;
+    clangTidy?: boolean;
+    clangTidyChecks?: string;
 }

packages/cpp/src/node/cpp-contribution.ts

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (C) 2017 Ericsson and others.
+ * Copyright (C) 2017-2019 Ericsson and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -42,7 +42,34 @@ export class CppContribution extends BaseLanguageServerContribution {
             || undefined
         );
 
+        const clangTidy = parameters && parameters.clangTidy;
+        const clangTidyChecks = parameters && parameters.clangTidyChecks;
+
+        if (clangTidy) {
+            const supportsClangTidy = await this.testSupportsClangTidy(command);
+            if (supportsClangTidy) {
+                args.push('-clang-tidy');
+                if (typeof clangTidyChecks === 'string' && clangTidyChecks.length > 0) {
+                    args.push(`-clang-tidy-checks=${clangTidyChecks}`);
+                }
+            }
+        }
         const serverConnection = await this.createProcessStreamConnectionAsync(command, args);
         this.forward(clientConnection, serverConnection);
     }
+
+    protected async testSupportsClangTidy(command: string): Promise<boolean> {
+        // clangd should fail if -clang-tidy flag is not supported
+        // but if it is supported, it will run forever until killed/stopped.
+        // to avoid that, we pass -version flag which makes it exit early.
+        const process = await super.spawnProcessAsync(command, ['-clang-tidy', '-version']);
+        return new Promise<boolean>(resolve => {
+            process.errorOutput.on('data', (data: string) => {
+                if (data.includes('-clang-tidy')) {
+                    resolve(false);
+                }
+            });
+            process.errorOutput.once('close', () => resolve(true));
+        });
+    }
 }