Merge d57c96a500f8531a46f98cc70f933e75c8186dc3 into 0e34de6d9b898d9ac1330c653668d0e1832f054egh-1402

10 files changed, 296 insertions, 22 deletions

diff --git a/lib/base-compiler.js b/lib/base-compiler.js
index 9730bc1a7..86f23c0f0 100644
--- a/lib/base-compiler.js
+++ b/lib/base-compiler.js
@@ -809,22 +809,45 @@ export class BaseCompiler {
     }
 
     async processGnatDebugOutput(inputFilename, result) {
-        const content = [];
+        const contentDebugExpanded = [];
+        const contentDebugTree = [];
+
         const keep_stdout = [];
 
-        // Everything before this stays in stdout.
-        // Everything after is considered expanded code and is moved to the
-        // corresponding pane.
-        const startOfExpandedCode = /^Source recreated/;
+        // stdout layout:
+        //
+        // ----- start
+        // everything here stays
+        // ... in stdout
+        // ... until :
+        // Source recreated from tree...
+        // everything here is
+        // ... sent in expanded
+        // ... pane... until :
+        // Tree created for ...
+        // everything after is
+        // ... sent in Tree pane
+        // ----- EOF
+        const startOfExpandedCode = /^Source recreated from tree/;
+        const startOfTree = /^Tree created for/;
+
         let isInExpandedCode = false;
+        let isInTree = false;
 
         for (const obj of Object.values(result.stdout)) {
             if (!isInExpandedCode && startOfExpandedCode.test(obj.text)) {
                 isInExpandedCode = true;
             }
 
+            if (!isInTree && startOfTree.test(obj.text)) {
+                isInExpandedCode = false;
+                isInTree = true;
+            }
+
             if (isInExpandedCode)
-                content.push(obj);
+                contentDebugExpanded.push(obj);
+            else if (isInTree)
+                contentDebugTree.push(obj);
             else
                 keep_stdout.push(obj);
         }
@@ -833,15 +856,23 @@ export class BaseCompiler {
         // compiler may exit with an error after the emission. This dump is also
         // very usefull to debug error message.
 
-        if (content.length === 0)
+        if (contentDebugExpanded.length === 0)
             if (result.code !== 0) {
                 return [{text: 'GNAT exited with an error and did not create the expanded code'}];
             } else {
                 return [{text: 'GNAT exited successfully but the expanded code is missing, something is wrong'}];
             }
 
+        if (contentDebugTree.length === 0)
+            if (result.code !== 0) {
+                return [{text: 'GNAT exited with an error and did not create the Tree'}];
+            } else {
+                return [{text: 'GNAT exited successfully but the Tree is missing, something is wrong'}];
+            }
+
         result.stdout = keep_stdout;
-        return content;
+
+        return [contentDebugExpanded, contentDebugTree];
     }
 
     /**
@@ -1216,7 +1247,8 @@ export class BaseCompiler {
         execOptions.ldPath = this.getSharedLibraryPathsAsLdLibraryPaths([]);
 
         const makeAst = backendOptions.produceAst && this.compiler.supportsAstView;
-        const makeGnatDebug = backendOptions.produceGnatDebug && this.compiler.supportsGnatDebugView;
+        const makeGnatDebug = backendOptions.produceGnatDebug && this.compiler.supportsGnatDebugViews;
+        const makeGnatDebugTree = backendOptions.produceGnatDebugTree && this.compiler.supportsGnatDebugViews;
         const makeIr = backendOptions.produceIr && this.compiler.supportsIrView;
         const makeRustMir = backendOptions.produceRustMir && this.compiler.supportsRustMirView;
         const makeRustMacroExp = backendOptions.produceRustMacroExp && this.compiler.supportsRustMacroExpView;
@@ -1247,9 +1279,10 @@ export class BaseCompiler {
 
         // GNAT, GCC and rustc can produce their extra output files along
         // with the main compilation command.
-        const gnatDebugResult = (makeGnatDebug ?
-                                 await this.processGnatDebugOutput(inputFilenameSafe, asmResult)
-                                 : '');
+        const [gnatDebugResult, gnatDebugTreeResult] = (makeGnatDebug || makeGnatDebugTree ?
+                                                        await this.processGnatDebugOutput(inputFilenameSafe, asmResult)
+                                                        : ['', '']);
+
         const gccDumpResult = (makeGccDump ?
                                await this.processGccDumpOutput(backendOptions.produceGccDump,
                                                                asmResult, this.compiler.removeEmptyGccDump,
@@ -1267,9 +1300,16 @@ export class BaseCompiler {
             asmResult.gccDumpOutput = gccDumpResult;
         }
 
-        if (this.compiler.supportsGnatDebugView && gnatDebugResult) {
-            asmResult.hasGnatDebugOutput = true;
-            asmResult.gnatDebugOutput = gnatDebugResult;
+        if (this.compiler.supportsGnatDebugViews) {
+            if (gnatDebugResult) {
+                asmResult.hasGnatDebugOutput = true;
+                asmResult.gnatDebugOutput = gnatDebugResult;
+            }
+
+            if (gnatDebugTreeResult) {
+                asmResult.hasGnatDebugTreeOutput = true;
+                asmResult.gnatDebugTreeOutput = gnatDebugTreeResult;
+            }
         }
 
         asmResult.tools = toolsResult;
diff --git a/lib/compilers/ada.js b/lib/compilers/ada.js
index 47b2f27b0..daa6d538e 100644
--- a/lib/compilers/ada.js
+++ b/lib/compilers/ada.js
@@ -35,7 +35,9 @@ export class AdaCompiler extends BaseCompiler {
         this.compiler.supportsGccDump = true;
         this.compiler.removeEmptyGccDump = true;
         this.compiler.supportsIntel = true;
-        this.compiler.supportsGnatDebugView = true;
+
+        // used for all GNAT related panes (Expanded code, Tree)
+        this.compiler.supportsGnatDebugViews = true;
     }
 
     getExecutableFilename(dirPath) {
@@ -50,10 +52,14 @@ export class AdaCompiler extends BaseCompiler {
         // super is needed as it handles the GCC Dump files.
         const opts = super.optionsForBackend (backendOptions, outputFilename);
 
-        if (backendOptions.produceGnatDebug && this.compiler.supportsGnatDebugView)
+        if (backendOptions.produceGnatDebug && this.compiler.supportsGnatDebugViews)
             // This is using stdout
             opts.push('-gnatGL');
 
+        if (backendOptions.produceGnatDebugTree && this.compiler.supportsGnatDebugViews)
+            // This is also using stdout
+            opts.push('-gnatdt');
+
         return opts;
     }
 
diff --git a/static/components.js b/static/components.js
index 882ce1e75..3148a2558 100644
--- a/static/components.js
+++ b/static/components.js
@@ -310,6 +310,28 @@ module.exports = {
             },
         };
     },
+
+    getGnatDebugTreeView: function () {
+        return {
+            type: 'component',
+            componentName: 'gnatdebugtree',
+            componentState: {},
+        };
+    },
+    getGnatDebugTreeViewWith: function (id, source, gnatDebugTreeOutput, compilerName, editorid) {
+        return {
+            type: 'component',
+            componentName: 'gnatdebugtree',
+            componentState: {
+                id: id,
+                source: source,
+                gnatDebugTreeOutput: gnatDebugTreeOutput,
+                compilerName: compilerName,
+                editorid: editorid,
+            },
+        };
+    },
+
     getGnatDebugView: function () {
         return {
             type: 'component',
diff --git a/static/hub.js b/static/hub.js
index 5b3f5d890..e7f4ea3c6 100644
--- a/static/hub.js
+++ b/static/hub.js
@@ -42,6 +42,7 @@ var irView = require('./panes/ir-view');
 var deviceView = require('./panes/device-view');
 var rustMirView = require('./panes/rustmir-view');
 var gnatDebugView = require('./panes/gnatdebug-view');
+var gnatDebugTreeView = require('./panes/gnatdebugtree-view');
 var rustMacroExpView = require('./panes/rustmacroexp-view');
 var rustHirView = require('./panes/rusthir-view');
 var gccDumpView = require('./panes/gccdump-view');
@@ -146,6 +147,10 @@ function Hub(layout, subLangId, defaultLangId) {
         function (container, state) {
             return self.rustMirViewFactory(container, state);
         });
+    layout.registerComponent(Components.getGnatDebugTreeView().componentName,
+        function (container, state) {
+            return self.gnatDebugTreeViewFactory(container, state);
+        });
     layout.registerComponent(Components.getGnatDebugView().componentName,
         function (container, state) {
             return self.gnatDebugViewFactory(container, state);
@@ -328,6 +333,10 @@ Hub.prototype.deviceViewFactory = function (container, state) {
     return new deviceView.DeviceAsm(this, container, state);
 };
 
+Hub.prototype.gnatDebugTreeViewFactory = function (container, state) {
+    return new gnatDebugTreeView.GnatDebugTree(this, container, state);
+};
+
 Hub.prototype.gnatDebugViewFactory = function (container, state) {
     return new gnatDebugView.GnatDebug(this, container, state);
 };
diff --git a/static/panes/compiler.js b/static/panes/compiler.js
index ed79d2d15..93160f392 100644
--- a/static/panes/compiler.js
+++ b/static/panes/compiler.js
@@ -204,6 +204,7 @@ Compiler.prototype.close = function () {
     this.outputEditor.dispose();
 };
 
+// eslint-disable-next-line max-statements
 Compiler.prototype.initPanerButtons = function () {
     var outputConfig = _.bind(function () {
         return Components.getOutput(this.id, this.sourceEditorId, this.sourceTreeId);
@@ -274,6 +275,11 @@ Compiler.prototype.initPanerButtons = function () {
             this.lastResult.gccDumpOutput);
     }, this);
 
+    var createGnatDebugTreeView = _.bind(function () {
+        return Components.getGnatDebugTreeViewWith(this.id, this.source, this.lastResult.gnatDebugTreeOutput,
+            this.getCompilerName(), this.sourceEditorId);
+    }, this);
+
     var createGnatDebugView = _.bind(function () {
         return Components.getGnatDebugViewWith(this.id, this.source, this.lastResult.gnatDebugOutput,
             this.getCompilerName(), this.sourceEditorId);
@@ -408,6 +414,16 @@ Compiler.prototype.initPanerButtons = function () {
     }, this));
 
     this.container.layoutManager
+        .createDragSource(this.gnatDebugTreeButton, createGnatDebugTreeView)
+        ._dragListener.on('dragStart', togglePannerAdder);
+
+    this.gnatDebugTreeButton.click(_.bind(function () {
+        var insertPoint = this.hub.findParentRowOrColumn(this.container) ||
+            this.container.layoutManager.root.contentItems[0];
+        insertPoint.addChild(createGnatDebugTreeView);
+    }, this));
+
+    this.container.layoutManager
         .createDragSource(this.gnatDebugButton, createGnatDebugView)
         ._dragListener.on('dragStart', togglePannerAdder);
 
@@ -715,6 +731,7 @@ Compiler.prototype.compile = function (bypassCache, newTools) {
             },
             produceOptInfo: this.wantOptInfo,
             produceCfg: this.cfgViewOpen,
+            produceGnatDebugTree: this.gnatDebugTreeViewOpen,
             produceGnatDebug: this.gnatDebugViewOpen,
             produceIr: this.irViewOpen,
             produceDevice: this.deviceViewOpen,
@@ -1299,6 +1316,21 @@ Compiler.prototype.onRustMirViewClosed = function (id) {
     }
 };
 
+Compiler.prototype.onGnatDebugTreeViewOpened = function (id) {
+    if (this.id === id) {
+        this.gnatDebugTreeButton.prop('disabled', true);
+        this.gnatDebugTreeViewOpen = true;
+        this.compile();
+    }
+};
+
+Compiler.prototype.onGnatDebugTreeViewClosed = function (id) {
+    if (this.id === id) {
+        this.gnatDebugTreeButton.prop('disabled', false);
+        this.gnatDebugTreeViewOpen = false;
+    }
+};
+
 Compiler.prototype.onGnatDebugViewOpened = function (id) {
     if (this.id === id) {
         this.gnatDebugButton.prop('disabled', true);
@@ -1480,12 +1512,12 @@ Compiler.prototype.initButtons = function (state) {
     this.astButton = this.domRoot.find('.btn.view-ast');
     this.irButton = this.domRoot.find('.btn.view-ir');
     this.deviceButton = this.domRoot.find('.btn.view-device');
+    this.gnatDebugTreeButton = this.domRoot.find('.btn.view-gnatdebugtree');
     this.gnatDebugButton = this.domRoot.find('.btn.view-gnatdebug');
     this.rustMirButton = this.domRoot.find('.btn.view-rustmir');
     this.rustMacroExpButton = this.domRoot.find('.btn.view-rustmacroexp');
     this.rustHirButton = this.domRoot.find('.btn.view-rusthir');
     this.gccDumpButton = this.domRoot.find('.btn.view-gccdump');
-    this.gnatDebugButton = this.domRoot.find('.btn.view-gnatdebug');
     this.cfgButton = this.domRoot.find('.btn.view-cfg');
     this.executorButton = this.domRoot.find('.create-executor');
     this.libsButton = this.domRoot.find('.btn.show-libs');
@@ -1702,6 +1734,7 @@ Compiler.prototype.updateButtons = function () {
     this.rustHirButton.prop('disabled', this.rustHirViewOpen);
     this.cfgButton.prop('disabled', this.cfgViewOpen);
     this.gccDumpButton.prop('disabled', this.gccDumpViewOpen);
+    this.gnatDebugTreeButton.prop('disabled', this.gnatDebugTreeViewOpen);
     this.gnatDebugButton.prop('disabled', this.gnatDebugViewOpen);
     // The executorButton does not need to be changed here, because you can create however
     // many executors as you want.
@@ -1715,7 +1748,8 @@ Compiler.prototype.updateButtons = function () {
     this.rustHirButton.toggle(!!this.compiler.supportsRustHirView);
     this.cfgButton.toggle(!!this.compiler.supportsCfg);
     this.gccDumpButton.toggle(!!this.compiler.supportsGccDump);
-    this.gnatDebugButton.toggle(!!this.compiler.supportsGnatDebugView);
+    this.gnatDebugTreeButton.toggle(!!this.compiler.supportsGnatDebugViews);
+    this.gnatDebugButton.toggle(!!this.compiler.supportsGnatDebugViews);
     this.executorButton.toggle(!!this.compiler.supportsExecute);
 
     this.enableToolButtons();
@@ -1816,6 +1850,8 @@ Compiler.prototype.initListeners = function () {
     this.eventHub.on('gccDumpViewClosed', this.onGccDumpViewClosed, this);
     this.eventHub.on('gccDumpUIInit', this.onGccDumpUIInit, this);
 
+    this.eventHub.on('gnatDebugTreeViewOpened', this.onGnatDebugTreeViewOpened, this);
+    this.eventHub.on('gnatDebugTreeViewClosed', this.onGnatDebugTreeViewClosed, this);
     this.eventHub.on('gnatDebugViewOpened', this.onGnatDebugViewOpened, this);
     this.eventHub.on('gnatDebugViewClosed', this.onGnatDebugViewClosed, this);
 
diff --git a/static/panes/diff.js b/static/panes/diff.js
index 19523c061..6f804af42 100644
--- a/static/panes/diff.js
+++ b/static/panes/diff.js
@@ -41,7 +41,8 @@ var
     DiffType_CompilerStdErr = 2,
     DiffType_ExecStdOut = 3,
     DiffType_ExecStdErr = 4,
-    DiffType_GNAT_ExpandedCode = 5;
+    DiffType_GNAT_ExpandedCode = 5,
+    DiffType_GNAT_Tree = 6;
 
 function State(id, model, difftype) {
     this.id = id;
@@ -85,6 +86,11 @@ State.prototype.refresh = function () {
                 if (this.result.hasGnatDebugOutput)
                     output = this.result.gnatDebugOutput || [];
                 break;
+            case DiffType_GNAT_Tree:
+                if (this.result.hasGnatDebugTreeOutput)
+                    output = this.result.gnatDebugTreeOutput || [];
+                break;
+
         }
     }
     this.model.setValue(_.pluck(output, 'text').join('\n'));
@@ -136,6 +142,7 @@ function Diff(hub, container, state) {
                 {id: DiffType_ExecStdOut, name: 'Execution stdout'},
                 {id: DiffType_ExecStdErr, name: 'Execution stderr'},
                 {id: DiffType_GNAT_ExpandedCode, name: 'GNAT Expanded Code'},
+                {id: DiffType_GNAT_Tree, name: 'GNAT Tree Code'},
             ],
             items: [],
             render: {
diff --git a/static/panes/gnatdebug-view.ts b/static/panes/gnatdebug-view.ts
index 0fa0f44fe..46a4e5c53 100644
--- a/static/panes/gnatdebug-view.ts
+++ b/static/panes/gnatdebug-view.ts
@@ -79,7 +79,7 @@ export class GnatDebug extends Pane<monaco.editor.IStandaloneCodeEditor, GnatDeb
         if (this.compilerInfo.compilerId !== compilerId) return;
         if (result.hasGnatDebugOutput) {
             this.showGnatDebugResults(result.gnatDebugOutput);
-        } else if (compiler.supportsGnatDebugView) {
+        } else if (compiler.supportsGnatDebugViews) {
             this.showGnatDebugResults([{text: '<No output>'}]);
         }
     }
@@ -89,7 +89,7 @@ export class GnatDebug extends Pane<monaco.editor.IStandaloneCodeEditor, GnatDeb
             this.compilerInfo.compilerName = compiler ? compiler.name : '';
             this.compilerInfo.editorId = editorId;
             this.setTitle();
-            if (compiler && !compiler.supportsGnatDebugView) {
+            if (compiler && !compiler.supportsGnatDebugViews) {
                 this.showGnatDebugResults([{text: '<GNAT Debug output is not supported for this compiler>'}]);
             }
         }
diff --git a/static/panes/gnatdebugtree-view.interfaces.ts b/static/panes/gnatdebugtree-view.interfaces.ts
new file mode 100644
index 000000000..67a51ec7b
--- /dev/null
+++ b/static/panes/gnatdebugtree-view.interfaces.ts
@@ -0,0 +1,27 @@
+// Copyright (c) 2021, Compiler Explorer Authors
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//     * Redistributions of source code must retain the above copyright notice,
+//       this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above copyright
+//       notice, this list of conditions and the following disclaimer in the
+//       documentation and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+export interface GnatDebugTreeState {
+    gnatDebugTreeOutput: any;
+}
diff --git a/static/panes/gnatdebugtree-view.ts b/static/panes/gnatdebugtree-view.ts
new file mode 100644
index 000000000..258700dce
--- /dev/null
+++ b/static/panes/gnatdebugtree-view.ts
@@ -0,0 +1,119 @@
+// Copyright (c) 2021, Compiler Explorer Authors
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//     * Redistributions of source code must retain the above copyright notice,
+//       this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above copyright
+//       notice, this list of conditions and the following disclaimer in the
+//       documentation and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+import _ from 'underscore';
+import * as monaco from 'monaco-editor';
+import { Container } from 'golden-layout';
+
+import { Pane } from './pane';
+import { GnatDebugTreeState } from './gnatdebugtree-view.interfaces';
+import { BasePaneState } from './pane.interfaces';
+
+import { ga } from '../analytics';
+import { extendConfig } from '../monaco-config';
+
+export class GnatDebugTree extends Pane<monaco.editor.IStandaloneCodeEditor, GnatDebugTreeState> {
+    constructor(hub: any, container: Container, state: GnatDebugTreeState & BasePaneState) {
+        super(hub, container, state);
+        if (state && state.gnatDebugTreeOutput) {
+            this.showGnatDebugTreeResults(state.gnatDebugTreeOutput);
+        }
+    }
+
+    override getInitialHTML(): string {
+        return $('#gnatdebugtree').html();
+    }
+
+    override createEditor(editorRoot: HTMLElement): monaco.editor.IStandaloneCodeEditor {
+        return monaco.editor.create(editorRoot, extendConfig({
+            language: 'plainText',
+            readOnly: true,
+            glyphMargin: true,
+            lineNumbersMinChars: 3,
+        }));
+    }
+
+    override registerOpeningAnalyticsEvent(): void {
+        ga.proxy('send', {
+            hitType: 'event',
+            eventCategory: 'OpenViewPane',
+            eventAction: 'GnatDebugTree',
+        });
+    }
+
+    override getPaneName(): string {
+        return `GNAT Debug Tree Viewer ${this.compilerInfo.compilerName}` +
+            `(Editor #${this.compilerInfo.editorId}, ` +
+            `Compiler #${this.compilerInfo.compilerId})`;
+    }
+
+    override registerCallbacks(): void {
+        const throttleFunction = _.throttle((event) => this.onDidChangeCursorSelection(event), 500);
+        this.editor.onDidChangeCursorSelection((event) => throttleFunction(event));
+        this.eventHub.emit('gnatDebugTreeViewOpened', this.compilerInfo.compilerId);
+        this.eventHub.emit('requestSettings');
+    }
+
+    override onCompileResult(compilerId: number, compiler: any, result: any): void {
+        if (this.compilerInfo.compilerId !== compilerId) return;
+        if (result.hasGnatDebugTreeOutput) {
+            this.showGnatDebugTreeResults(result.gnatDebugTreeOutput);
+        } else if (compiler.supportsGnatDebugViews) {
+            this.showGnatDebugTreeResults([{text: '<No output>'}]);
+        }
+    }
+
+    override onCompiler(compilerId: number, compiler: any, options: any, editorId: number): void {
+        if (this.compilerInfo.compilerId === compilerId) {
+            this.compilerInfo.compilerName = compiler ? compiler.name : '';
+            this.compilerInfo.editorId = editorId;
+            this.setTitle();
+            if (compiler && !compiler.supportsGnatDebugViews) {
+                this.showGnatDebugTreeResults([{text: '<GNAT Debug Tree output is not supported for this compiler>'}]);
+            }
+        }
+    }
+
+    showGnatDebugTreeResults(result: any[]): void {
+        if (!this.editor) return;
+        this.editor.getModel().setValue(result.length
+            ? _.pluck(result, 'text').join('\n')
+            : '<No GNAT Debug Tree generated>');
+
+        if (!this.isAwaitingInitialResults) {
+            if (this.selection) {
+                this.editor.setSelection(this.selection);
+                this.editor.revealLinesInCenter(this.selection.selectionStartLineNumber,
+                    this.selection.endLineNumber);
+            }
+            this.isAwaitingInitialResults = true;
+        }
+    }
+
+    override close(): void {
+        this.eventHub.unsubscribe();
+        this.eventHub.emit('gnatDebugTreeViewClosed', this.compilerInfo.compilerId);
+        this.editor.dispose();
+    }
+}
diff --git a/views/templates.pug b/views/templates.pug
index 6b7cf0dd1..879ca0020 100644
--- a/views/templates.pug
+++ b/views/templates.pug
@@ -114,6 +114,9 @@
           button.dropdown-item.btn.btn-sm.btn-light.view-gccdump(title="Show Tree/RTL dump (GCC only)")
             span.dropdown-icon.fas.fa-tree
             | GCC Tree/RTL output
+          button.dropdown-item.btn.btn-sm.btn-light.view-gnatdebugtree(title="Show GNAT Debug Tree")
+              span.dropdown-icon.fas.fa-tree
+              | GNAT Debug Tree
           button.dropdown-item.btn.btn-sm.btn-light.view-gnatdebug(title="Show GNAT Debug Expanded Code")
             span.dropdown-icon.fas.fa-tree
             | GNAT Debug Expanded Code
@@ -294,6 +297,11 @@
         select.change-device(placeholder="Select a device...")
     .monaco-placeholder
 
+  #gnatdebugtree
+    .top-bar.btn-toolbar.bg-light(role="toolbar")
+      include font-size
+    .monaco-placeholder
+
   #gnatdebug
     .top-bar.btn-toolbar.bg-light(role="toolbar")
       include font-size