WIP: Dataflow

package.json

@@ -56,6 +56,11 @@
           "name": "Inheritance Hierarchy",
           "when": "extension.ccls.inheritanceHierarchyVisible"
         },
+        {
+          "id": "ccls.dataFlowInto",
+          "name": "Data Flow Hierarchy",
+          "when": "extension.ccls.dataFlowHierarchyVisible"
+        },
         {
           "id": "ccls.memberHierarchy",
           "name": "Member Hierarchy",
@@ -89,6 +94,11 @@
           "command": "ccls.base",
           "when": "resourceLangId == cpp",
           "group": "navigation@1.34"
+        },
+        {
+          "command": "ccls.dataFlowInto",
+          "when": "resourceLangId == cpp",
+          "group": "navigation@1.35"
         }
       ],
       "view/title": [
@@ -107,6 +117,11 @@
           "when": "view == ccls.callHierarchy",
           "group": "navigation"
         },
+        {
+          "command": "ccls.closeDataFlowHierarchy",
+          "when": "view == ccls.dataFlowInto",
+          "group": "navigation"
+        },
         {
           "command": "ccls.closeInheritanceHierarchy",
           "when": "view == ccls.inheritanceHierarchy",
@@ -137,6 +152,10 @@
           "command": "ccls.closeMemberHierarchy",
           "when": "false"
         },
+        {
+          "command": "ccls.closeDataFlowHierarchy",
+          "when": "false"
+        },
         {
           "command": "ccls.gotoForTreeView",
           "when": "false"
@@ -229,6 +248,20 @@
         "category": "ccls",
         "command": "ccls.vars"
       },
+      {
+        "title": "Show Data Flow Into",
+        "category": "ccls",
+        "command": "ccls.dataFlowInto"
+      },
+      {
+        "title": "Close",
+        "category": "ccls",
+        "command": "ccls.closeDataFlowHierarchy",
+        "icon": {
+          "light": "resources/close-light.svg",
+          "dark": "resources/close-dark.svg"
+        }
+      },
       {
         "title": "Show Cross References",
         "category": "ccls",

src/hierarchies/dataFlowHierarchy.ts

@@ -0,0 +1,70 @@
+import {
+  commands,
+  Disposable,
+  Event,
+  EventEmitter,
+  Position,
+  Range,
+  TextEditor,
+  TreeDataProvider,
+  TreeItem,
+  TreeItemCollapsibleState,
+  Uri,
+  workspace
+} from "vscode";
+import { LanguageClient } from "vscode-languageclient/lib/main";
+import { Icon, IHierarchyNode } from "../types";
+import { disposeAll, resourcePath, setContext } from "../utils";
+import { Hierarchy } from "./hierarchy";
+
+interface DataFlowHierarchyNode extends IHierarchyNode {
+  children: DataFlowHierarchyNode[];
+}
+
+export class DataFlowHierarchyProvider extends Hierarchy<DataFlowHierarchyNode> {
+  protected contextValue = 'extension.ccls.dataFlowHierarchyVisible';
+  private icon: Icon;
+
+  constructor(
+    readonly languageClient: LanguageClient,
+  ) {
+    super(languageClient, 'ccls.dataFlowInto', 'ccls.closeDataFlowHierarchy');
+    this.icon = {
+      dark: resourcePath("base-dark.svg"),
+      light: resourcePath("base-light.svg")
+    };
+  }
+
+  protected async onTreeItem(ti: TreeItem, element: DataFlowHierarchyNode) {
+
+    const parentFile = await workspace.openTextDocument(Uri.parse(element.location.uri));
+    ti.label = parentFile.getText(
+      new Range(
+        new Position(element.location.range.start.line, element.location.range.start.character),
+        new Position(element.location.range.end.line, element.location.range.end.character)
+      )
+    );
+
+    ti.iconPath = this.icon;
+    ti.contextValue = 'cclsGoto';
+
+  }
+
+  protected async onGetChildren(
+    element: DataFlowHierarchyNode
+  ): Promise<DataFlowHierarchyNode[]> {
+    return element.children;
+  }
+
+  protected async onReveal(uri: Uri, position: Position): Promise<DataFlowHierarchyNode> {
+    return this.languageClient.sendRequest<DataFlowHierarchyNode>(
+      '$ccls/dataFlowInto',
+      {
+        position,
+        textDocument: {
+          uri: uri.toString(true),
+        },
+      }
+    );
+  }
+}

src/serverContext.ts

@@ -29,6 +29,7 @@ import * as ls from "vscode-languageserver-types";
 import { CclsErrorHandler } from "./cclsErrorHandler";
 import { cclsChan, logChan } from './globalContext';
 import { CallHierarchyProvider } from "./hierarchies/callHierarchy";
+import { DataFlowHierarchyProvider } from "./hierarchies/dataFlowHierarchy";
 import { InheritanceHierarchyProvider } from "./hierarchies/inheritanceHierarchy";
 import { MemberHierarchyProvider } from "./hierarchies/memberHierarchy";
 import { InactiveRegionsProvider } from "./inactiveRegions";
@@ -262,6 +263,12 @@ export class ServerContext implements Disposable {
         'ccls.memberHierarchy', memberHierarchyProvider
     ));
 
+    const dfProvier = new DataFlowHierarchyProvider(this.client);
+    this._dispose.push(dfProvier);
+    this._dispose.push(window.registerTreeDataProvider(
+        'ccls.dataFlowInto', dfProvier
+    ));
+
     // Common between tree views.
     this._dispose.push(commands.registerCommand(
         "ccls.gotoForTreeView", this.gotoForTreeView, this