Add rustc Macro Expansion view (#2932)

Adds a new pane for producing the macro expansion of Rust code compiled with rustc.

8 files changed, 238 insertions, 4 deletions

diff --git a/lib/base-compiler.js b/lib/base-compiler.js
index ce4d887ae..5074d541b 100644
--- a/lib/base-compiler.js
+++ b/lib/base-compiler.js
@@ -637,10 +637,11 @@ export class BaseCompiler {
         const execOptions = this.getDefaultExecOptions();
         // TODO: reconsider this value
         execOptions.maxOutput = 1024 ** 3;
+        const mirPath = this.getRustMirOutputFilename(inputFilename);
         const rustcOptions = [
             inputFilename,
             '-o',
-            this.getRustMirOutputFilename(inputFilename),
+            mirPath,
             '--emit=mir',
             '--crate-type',
             'rlib',
@@ -651,7 +652,6 @@ export class BaseCompiler {
         if (output.code !== 0) {
             return [{text: 'Failed to run compiler to get Rust MIR'}];
         }
-        const mirPath = this.getRustMirOutputFilename(inputFilename);
         if (await fs.exists(mirPath)) {
             const content = await fs.readFile(mirPath, 'utf-8');
             return content.split('\n').map((line) => ({
@@ -661,6 +661,32 @@ export class BaseCompiler {
         return [{text: 'Internal error; unable to open output path'}];
     }
 
+    async generateRustMacroExpansion(inputFilename) {
+        const execOptions = this.getDefaultExecOptions();
+        const macroExpPath = this.getRustMacroExpansionOutputFilename(inputFilename);
+        const rustcOptions = [
+            inputFilename,
+            '-o',
+            macroExpPath,
+            '-Zunpretty=expanded',
+            '--crate-type',
+            'rlib',
+        ];
+
+        const output = await this.runCompiler(this.compiler.exe, rustcOptions, this.filename(inputFilename),
+            execOptions);
+        if (output.code !== 0) {
+            return [{text: 'Failed to run compiler to get Rust Macro Expansion'}];
+        }
+        if (await fs.exists(macroExpPath)) {
+            const content = await fs.readFile(macroExpPath, 'utf-8');
+            return content.split('\n').map((line) => ({
+                text: line,
+            }));
+        }
+        return [{text: 'Internal error; unable to open output path'}];
+    }
+
     getIrOutputFilename(inputFilename) {
         return inputFilename.replace(path.extname(inputFilename), '.ll');
     }
@@ -669,6 +695,10 @@ export class BaseCompiler {
         return inputFilename.replace(path.extname(inputFilename), '.mir');
     }
 
+    getRustMacroExpansionOutputFilename(inputFilename) {
+        return inputFilename.replace(path.extname(inputFilename), '.expanded.rs');
+    }
+
     getOutputFilename(dirPath, outputFilebase, key) {
         let filename;
         if (key && key.backendOptions && key.backendOptions.customOutputFilename) {
@@ -1087,16 +1117,18 @@ export class BaseCompiler {
         const makeAst = backendOptions.produceAst && this.compiler.supportsAstView;
         const makeIr = backendOptions.produceIr && this.compiler.supportsIrView;
         const makeRustMir = backendOptions.produceRustMir && this.compiler.supportsRustMirView;
+        const makeRustMacroExp = backendOptions.produceRustMacroExp && this.compiler.supportsRustMacroExpView;
         const makeGccDump = backendOptions.produceGccDump && backendOptions.produceGccDump.opened
             && this.compiler.supportsGccDump;
 
         const downloads = await buildEnvironment;
-        const [asmResult, astResult, gccDumpResult, irResult, rustMirResult, toolsResult] = await Promise.all([
+        const [asmResult, astResult, gccDumpResult, irResult, rustMirResult, rustMacroExpResult, toolsResult] = await Promise.all([
             this.runCompiler(this.compiler.exe, options, inputFilenameSafe, execOptions),
             (makeAst ? this.generateAST(inputFilename, options) : ''),
             (makeGccDump ? this.generateGccDump(inputFilename, options, backendOptions.produceGccDump) : ''),
             (makeIr ? this.generateIR(inputFilename, options, filters) : ''),
             (makeRustMir ? this.generateRustMir(inputFilename, options) : ''),
+            (makeRustMacroExp ? this.generateRustMacroExpansion(inputFilename, options) : ''),
             Promise.all(this.runToolsOfType(tools, 'independent', this.getCompilationInfo(key, {
                 inputFilename,
                 dirPath,
@@ -1137,6 +1169,10 @@ export class BaseCompiler {
             asmResult.hasRustMirOutput = true;
             asmResult.rustMirOutput = rustMirResult;
         }
+        if (rustMacroExpResult) {
+            asmResult.hasRustMacroExpOutput = true;
+            asmResult.rustMacroExpOutput = rustMacroExpResult;
+        }
 
         return this.checkOutputFileAndDoPostProcess(asmResult, outputFilename, filters);
     }
diff --git a/lib/compilers/rust.js b/lib/compilers/rust.js
index d6be3b5c7..3072e8db4 100644
--- a/lib/compilers/rust.js
+++ b/lib/compilers/rust.js
@@ -39,6 +39,8 @@ export class RustCompiler extends BaseCompiler {
         this.compiler.supportsIntel = true;
         this.compiler.supportsIrView = true;
         this.compiler.supportsRustMirView = true;
+        // Macro expansion through -Zunpretty=expanded is only available for Nightly
+        this.compiler.supportsRustMacroExpView = info.name === 'nightly' || info.semver === 'nightly';
         this.compiler.irArg = ['--emit', 'llvm-ir'];
         this.linker = this.compilerProps('linker');
     }
diff --git a/static/components.js b/static/components.js
index 4a23e7264..bc7360485 100644
--- a/static/components.js
+++ b/static/components.js
@@ -310,6 +310,26 @@ module.exports = {
             },
         };
     },
+    getRustMacroExpView: function() {
+        return {
+            type: 'component',
+            componentName: 'rustmacroexp',
+            componentState: {},
+        };
+    },
+    getRustMacroExpViewWith: function (id, source, rustMacroExpOutput, compilerName, editorid) {
+        return {
+            type: 'component',
+            componentName: 'rustmacroexp',
+            componentState: {
+                id: id,
+                source: source,
+                rustMacroExpOutput: rustMacroExpOutput,
+                compilerName: compilerName,
+                editorid: editorid,
+            },
+        };
+    },
     getDeviceView: function () {
         return {
             type: 'component',
diff --git a/static/hub.js b/static/hub.js
index edd3854de..5327450d6 100644
--- a/static/hub.js
+++ b/static/hub.js
@@ -41,6 +41,7 @@ var astView = require('./panes/ast-view');
 var irView = require('./panes/ir-view');
 var deviceView = require('./panes/device-view');
 var rustMirView = require('./panes/rustmir-view');
+var rustMacroExpView = require('./panes/rustmacroexp-view');
 var gccDumpView = require('./panes/gccdump-view');
 var cfgView = require('./panes/cfg-view');
 var conformanceView = require('./panes/conformance-view');
@@ -143,6 +144,10 @@ function Hub(layout, subLangId, defaultLangId) {
         function (container, state) {
             return self.rustMirViewFactory(container, state);
         });
+    layout.registerComponent(Components.getRustMacroExpView().componentName,
+        function (container, state) {
+            return self.rustMacroExpViewFactory(container, state);
+        });
     layout.registerComponent(Components.getGccDumpView().componentName,
         function (container, state) {
             return self.gccDumpViewFactory(container, state);
@@ -317,6 +322,10 @@ Hub.prototype.rustMirViewFactory = function (container, state) {
     return new rustMirView.RustMir(this, container, state);
 };
 
+Hub.prototype.rustMacroExpViewFactory = function (container, state) {
+    return new rustMacroExpView.RustMacroExp(this, container, state);
+};
+
 Hub.prototype.gccDumpViewFactory = function (container, state) {
     return new gccDumpView.GccDump(this, container, state);
 };
diff --git a/static/panes/compiler.js b/static/panes/compiler.js
index 87520592c..e0ab3a0f9 100644
--- a/static/panes/compiler.js
+++ b/static/panes/compiler.js
@@ -258,6 +258,11 @@ Compiler.prototype.initPanerButtons = function () {
             this.getCompilerName(), this.sourceEditorId);
     }, this);
 
+    var createRustMacroExpView = _.bind(function () {
+        return Components.getRustMacroExpViewWith(this.id, this.source, this.lastResult.rustMacroExpOutput,
+            this.getCompilerName(), this.sourceEditorId);
+    }, this);
+
     var createGccDumpView = _.bind(function () {
         return Components.getGccDumpViewWith(this.id, this.getCompilerName(), this.sourceEditorId,
             this.lastResult.gccDumpOutput);
@@ -362,6 +367,16 @@ Compiler.prototype.initPanerButtons = function () {
     }, this));
 
     this.container.layoutManager
+        .createDragSource(this.rustMacroExpButton, createRustMacroExpView)
+        ._dragListener.on('dragStart', togglePannerAdder);
+
+    this.rustMacroExpButton.click(_.bind(function () {
+        var insertPoint = this.hub.findParentRowOrColumn(this.container) ||
+            this.container.layoutManager.root.contentItems[0];
+        insertPoint.addChild(createRustMacroExpView);
+    }, this));
+
+    this.container.layoutManager
         .createDragSource(this.gccDumpButton, createGccDumpView)
         ._dragListener.on('dragStart', togglePannerAdder);
 
@@ -672,6 +687,7 @@ Compiler.prototype.compile = function (bypassCache, newTools) {
             produceIr: this.irViewOpen,
             produceDevice: this.deviceViewOpen,
             produceRustMir: this.rustMirViewOpen,
+            produceRustMacroExp: this.rustMacroExpViewOpen,
         },
         filters: this.getEffectiveFilters(),
         tools: this.getActiveTools(newTools),
@@ -1242,6 +1258,21 @@ Compiler.prototype.onRustMirViewClosed = function (id) {
     }
 };
 
+Compiler.prototype.onRustMacroExpViewOpened = function (id) {
+    if (this.id === id) {
+        this.rustMacroExpButton.prop('disabled', true);
+        this.rustMacroExpViewOpen = true;
+        this.compile();
+    }
+};
+
+Compiler.prototype.onRustMacroExpViewClosed = function (id) {
+    if (this.id === id) {
+        this.rustMacroExpButton.prop('disabled', false);
+        this.rustMacroExpViewOpen = false;
+    }
+};
+
 Compiler.prototype.onGccDumpUIInit = function (id) {
     if (this.id === id) {
         this.compile();
@@ -1379,6 +1410,7 @@ Compiler.prototype.initButtons = function (state) {
     this.irButton = this.domRoot.find('.btn.view-ir');
     this.deviceButton = this.domRoot.find('.btn.view-device');
     this.rustMirButton = this.domRoot.find('.btn.view-rustmir');
+    this.rustMacroExpButton = this.domRoot.find('.btn.view-rustmacroexp');
     this.gccDumpButton = this.domRoot.find('.btn.view-gccdump');
     this.cfgButton = this.domRoot.find('.btn.view-cfg');
     this.executorButton = this.domRoot.find('.create-executor');
@@ -1591,6 +1623,7 @@ Compiler.prototype.updateButtons = function () {
     this.irButton.prop('disabled', this.irViewOpen);
     this.deviceButton.prop('disabled', this.deviceViewOpen);
     this.rustMirButton.prop('disabled', this.rustMirViewOpen);
+    this.rustMacroExpButton.prop('disabled', this.rustMacroExpViewOpen);
     this.cfgButton.prop('disabled', this.cfgViewOpen);
     this.gccDumpButton.prop('disabled', this.gccDumpViewOpen);
     // The executorButton does not need to be changed here, because you can create however
@@ -1601,6 +1634,7 @@ Compiler.prototype.updateButtons = function () {
     this.irButton.toggle(!!this.compiler.supportsIrView);
     this.deviceButton.toggle(!!this.compiler.supportsDeviceAsmView);
     this.rustMirButton.toggle(!!this.compiler.supportsRustMirView);
+    this.rustMacroExpButton.toggle(!!this.compiler.supportsRustMacroExpView);
     this.cfgButton.toggle(!!this.compiler.supportsCfg);
     this.gccDumpButton.toggle(!!this.compiler.supportsGccDump);
     this.executorButton.toggle(!!this.compiler.supportsExecute);
@@ -1688,6 +1722,8 @@ Compiler.prototype.initListeners = function () {
     this.eventHub.on('deviceViewClosed', this.onDeviceViewClosed, this);
     this.eventHub.on('rustMirViewOpened', this.onRustMirViewOpened, this);
     this.eventHub.on('rustMirViewClosed', this.onRustMirViewClosed, this);
+    this.eventHub.on('rustMacroExpViewOpened', this.onRustMacroExpViewOpened, this);
+    this.eventHub.on('rustMacroExpViewClosed', this.onRustMacroExpViewClosed, this);
     this.eventHub.on('outputOpened', this.onOutputOpened, this);
     this.eventHub.on('outputClosed', this.onOutputClosed, this);
 
diff --git a/static/panes/rustmacroexp-view.ts b/static/panes/rustmacroexp-view.ts
new file mode 100644
index 000000000..b81099638
--- /dev/null
+++ b/static/panes/rustmacroexp-view.ts
@@ -0,0 +1,122 @@
+// 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 { BasePaneState } from './pane.interfaces';
+
+import ga from '../analytics';
+import { extendConfig } from '../monaco-config';
+
+export interface RustMacroExpState extends BasePaneState {
+    rustMacroExpOutput: any;
+}
+
+export class RustMacroExp extends Pane<monaco.editor.IStandaloneCodeEditor> {
+    constructor(hub: any, container: Container, state: RustMacroExpState) {
+        super(hub, container, state);
+        if (state && state.rustMacroExpOutput) {
+            this.showRustMacroExpResults(state.rustMacroExpOutput);
+        }
+    }
+
+    override initializeDOMRoot(): void {
+        this.domRoot.html($('#rustmacroexp').html());
+    }
+
+    override createEditor(editorRoot: HTMLElement): void {
+        this.editor = monaco.editor.create(editorRoot, extendConfig({
+            language: 'rust',
+            readOnly: true,
+            glyphMargin: true,
+            lineNumbersMinChars: 3,
+        }))
+    }
+
+    override registerOpeningAnalyticsEvent(): void {
+        ga.proxy('send', {
+            hitType: 'event',
+            eventCategory: 'OpenViewPane',
+            eventAction: 'RustMacroExp',
+        });
+    }
+
+    override getPaneName(): string {
+        return `Rust Macro Expansion 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('rustMacroExpViewOpened', this.compilerInfo.compilerId);
+        this.eventHub.emit('requestSettings');
+    }
+
+    override onCompileResult(id: unknown, compiler: unknown, result: any): void {
+        if (this.compilerInfo.compilerId !== id) return;
+        if (result.hasRustMacroExpOutput) {
+            this.showRustMacroExpResults(result.rustMacroExpOutput);
+        } else {
+            this.showRustMacroExpResults([{text: '<No output>'}]);
+        }
+    }
+
+    override onCompiler(id: number, compiler: any, options: any, editorId: number): void {
+        if (this.compilerInfo.compilerId === id) {
+            this.compilerInfo.compilerName = compiler ? compiler.name : '';
+            this.compilerInfo.editorId = editorId;
+            this.setTitle();
+            if (compiler && !compiler.supportsRustMacroExpView) {
+                this.editor.setValue('<Rust Macro Expansion output is not supported for this compiler>');
+            }
+        }
+    }
+
+    showRustMacroExpResults(result: any[]): void {
+        if (!this.editor) return;
+        this.editor.getModel().setValue(result.length
+            ? _.pluck(result, 'text').join('\n')
+            : '<No Rust Macro Expansion 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('rustMacroExpViewClosed', this.compilerInfo.compilerId);
+        this.editor.dispose();
+    }
+}
diff --git a/static/tsconfig.json b/static/tsconfig.json
index d9d4096bb..238b655c9 100644
--- a/static/tsconfig.json
+++ b/static/tsconfig.json
@@ -19,6 +19,7 @@
 		"panes/tree.ts",
 		"panes/pane.ts",
 		"panes/pane.interfaces.ts",
+		"panes/rustmacroexp-view.ts",
 		"panes/rustmir-view.ts",
 		"settings.interfaces.ts",
 		"sharing.ts",
diff --git a/views/templates.pug b/views/templates.pug
index 0a5496aa8..08cdd32db 100644
--- a/views/templates.pug
+++ b/views/templates.pug
@@ -104,6 +104,9 @@
           button.dropdown-item.btn.btn-sm.btn-light.view-rustmir(title="Show Rust Mid-level Intermediate Representation")
             span.dropdown-icon.fas.fa-water
             | Rust MIR output
+          button.dropdown-item.btn.btn-sm.btn-light.view-rustmacroexp(title="Show Rust Macro Expansion")
+            span.dropdown-icon.fas.fa-arrows-alt
+            | Rust Macro Expansion output
           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
@@ -286,7 +289,12 @@
 
   #rustmir
     .top-bar.btn-toolbar.bg-light(role="toolbar")
-      include font-size.pug
+      include font-size
+    .monaco-placeholder
+
+  #rustmacroexp
+    .top-bar.btn-toolbar.bg-light(role="toolbar")
+      include font-size
     .monaco-placeholder
 
   #gccdump