Merge #8801

8801: feat: Allow viewing the crate graph in a webview r=jonas-schievink a=jonas-schievink

This uses `dot` to render the crate graph as an SVD file, and displays it in a VS Code panel. For simple crate graphs, it works quite well:

![screenshot-2021-05-11-16:19:32](https://user-images.githubusercontent.com/1786438/117831361-c4a48980-b274-11eb-9276-240cdf6919aa.png)

Unfortunately, on rust-analyzer itself (and most medium-sized dependency graphs), `dot` runs for around a minute and then produces this mess:

![screenshot-2021-05-11-16:41:37](https://user-images.githubusercontent.com/1786438/117834831-c754ae00-b277-11eb-850b-138495dbeba8.png)


Co-authored-by: Jonas Schievink <[email protected]>

4 files changed, 16 insertions, 0 deletions

diff --git a/editors/code/package.json b/editors/code/package.json
index f35d30898..0f38a1673 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -110,6 +110,11 @@
                 "category": "Rust Analyzer"
             },
             {
+                "command": "rust-analyzer.viewCrateGraph",
+                "title": "View Crate Graph",
+                "category": "Rust Analyzer"
+            },
+            {
                 "command": "rust-analyzer.expandMacro",
                 "title": "Expand macro recursively",
                 "category": "Rust Analyzer"
diff --git a/editors/code/src/commands.ts b/editors/code/src/commands.ts
index 4092435db..8ab259af2 100644
--- a/editors/code/src/commands.ts
+++ b/editors/code/src/commands.ts
@@ -429,6 +429,14 @@ export function viewHir(ctx: Ctx): Cmd {
     };
 }
 
+export function viewCrateGraph(ctx: Ctx): Cmd {
+    return async () => {
+        const panel = vscode.window.createWebviewPanel("rust-analyzer.crate-graph", "rust-analyzer crate graph", vscode.ViewColumn.Two);
+        const svg = await ctx.client.sendRequest(ra.viewCrateGraph);
+        panel.webview.html = svg;
+    };
+}
+
 // Opens the virtual file that will show the syntax tree
 //
 // The contents of the file come from the `TextDocumentContentProvider`
diff --git a/editors/code/src/lsp_ext.ts b/editors/code/src/lsp_ext.ts
index f78de894b..aa745a65c 100644
--- a/editors/code/src/lsp_ext.ts
+++ b/editors/code/src/lsp_ext.ts
@@ -27,6 +27,8 @@ export const syntaxTree = new lc.RequestType<SyntaxTreeParams, string, void>("ru
 
 export const viewHir = new lc.RequestType<lc.TextDocumentPositionParams, string, void>("rust-analyzer/viewHir");
 
+export const viewCrateGraph = new lc.RequestType0<string, void>("rust-analyzer/viewCrateGraph");
+
 export interface ExpandMacroParams {
     textDocument: lc.TextDocumentIdentifier;
     position: lc.Position;
diff --git a/editors/code/src/main.ts b/editors/code/src/main.ts
index 643fb643f..516322d03 100644
--- a/editors/code/src/main.ts
+++ b/editors/code/src/main.ts
@@ -106,6 +106,7 @@ async function tryActivate(context: vscode.ExtensionContext) {
     ctx.registerCommand('parentModule', commands.parentModule);
     ctx.registerCommand('syntaxTree', commands.syntaxTree);
     ctx.registerCommand('viewHir', commands.viewHir);
+    ctx.registerCommand('viewCrateGraph', commands.viewCrateGraph);
     ctx.registerCommand('expandMacro', commands.expandMacro);
     ctx.registerCommand('run', commands.run);
     ctx.registerCommand('copyRunCommandLine', commands.copyRunCommandLine);