use clang-tidy command with task to generate items in problem's view.

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

packages/cpp/README.md

@@ -88,8 +88,9 @@ You can set the preference 'cpp.clangTidy' to enable the clang-tidy linter inclu
 - 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.
-
+```
+Note: When the "cpp.clangTidyChecks" is used in the preference settings, the configs will be merged with the configuration found in ".clang-tidy" file. If you want to drop the configs from ".clang-tidy", you'd need to disable it in "cpp.clangTidyChecks", which is "cpp.clangTidyChecks": "-*".
+```
 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.
@@ -102,6 +103,27 @@ There are two ways to configure clang-tidy's checks: through a Theia preference
     - for the .clang-tidy file: Checks: "-*,readability-*"
         - Meaning: disable all list-checks and enable all readability-* checks
 
+### Using clang-tidy as a task
+In .theia/tasks.json, add the following:
+```
+   {
+        "label": "[Task] clang-tidy",
+        "type": "shell",
+        "cwd": "${workspaceFolder}",
+        "command": "clang-tidy",
+        "args": [
+            "*"
+        ],
+        "options": {},
+        "problemMatcher": [
+            "$clangTidyMatcher"
+        ]
+   }
+```
+
+If you want a description for each task field, see [theia/packages/task/src/browser/task-schema-updater.ts]( https://github.com/theia-ide/theia/blob/531aa3bde8dea7f022ea41beaee3aace65ce54de/packages/task/src/browser/task-schema-updater.ts#L62 )
+
+
 ## License
 
 - [Eclipse Public License 2.0](http://www.eclipse.org/legal/epl-2.0/)

packages/cpp/src/browser/cpp-task-provider.ts

@@ -16,6 +16,7 @@
 
 import parseArgv = require('string-argv');
 import { inject, injectable, postConstruct } from 'inversify';
+import { ProblemMatcherRegistry, ProblemPatternRegistry } from '@theia/task/lib/common/task-protocol';
 import { ProcessTaskConfiguration } from '@theia/task/lib/common/process/task-protocol';
 import { TaskContribution, TaskProvider, TaskProviderRegistry, TaskResolver, TaskResolverRegistry } from '@theia/task/lib/browser/task-contribution';
 import { CppBuildConfigurationManager, CppBuildConfiguration } from './cpp-build-configurations';
@@ -37,10 +38,33 @@ export class CppTaskProvider implements TaskContribution, TaskProvider, TaskReso
     @inject(TaskResolverRegistry) protected readonly taskResolverRegistry: TaskResolverRegistry;
     @inject(TaskDefinitionRegistry) protected readonly taskDefinitionRegistry: TaskDefinitionRegistry;
     @inject(CppBuildConfigurationManager) protected readonly cppBuildConfigurationManager: CppBuildConfigurationManager;
+    @inject(ProblemMatcherRegistry) protected readonly problemMatcherRegistry: ProblemMatcherRegistry;
+    @inject(ProblemPatternRegistry) protected readonly problemPatternRegistry: ProblemPatternRegistry;
 
     @postConstruct()
     protected init(): void {
         this.registerTaskDefinition();
+        this.problemPatternRegistry.register({
+            'name': 'clangTidyPattern',
+            'regexp': '^(.+):(\\d+):(\\d+):\\s+(error|warning|info|note):\\s+(.+?)\\s+\\[(.+)\\]$',
+            'file': 1,
+            'line': 2,
+            'character': 3,
+            'severity': 4,
+            'message': 5,
+            'code': 6
+        });
+        this.problemMatcherRegistry.register({
+            'name': 'clangTidyMatcher',
+            'label': 'for clangd',
+            'owner': 'clang-tidy',
+            'source': 'clang-tidy-task',
+            'applyTo': 'alldocuments',
+            'fileLocation': [
+                'absolute'
+            ],
+            'pattern': 'clangTidyPattern'
+        });
     }
 
     registerProviders(registry: TaskProviderRegistry) {
@@ -122,7 +146,7 @@ export class CppTaskProvider implements TaskContribution, TaskProvider, TaskReso
             properties: {
                 label: {
                     type: 'string',
-                    description: 'Lable of the cpp build configuration task'
+                    description: 'Label of the cpp build configuration task'
                 }
             }
         });