Merge commit '37f84c101bca43b11027f30ab0c2852f9325bc3d' into sync-from-ra

3 files changed, 72 insertions, 25 deletions

diff --git a/src/tools/rust-analyzer/docs/dev/lsp-extensions.md b/src/tools/rust-analyzer/docs/dev/lsp-extensions.md
index bc58aa7220d..024acb87709 100644
--- a/src/tools/rust-analyzer/docs/dev/lsp-extensions.md
+++ b/src/tools/rust-analyzer/docs/dev/lsp-extensions.md
@@ -1,5 +1,5 @@
 <!---
-lsp_ext.rs hash: 2d60bbffe70ae198
+lsp_ext.rs hash: 149a5be3c5e469d1
 
 If you need to change the above hash to make the test pass, please check if you
 need to adjust this doc as well and ping this issue:
@@ -886,3 +886,48 @@ export interface FetchDependencyListResult {
 }
 ```
 Returns all crates from this workspace, so it can be used create a viewTree to help navigate the dependency tree.
+
+## View Recursive Memory Layout
+
+**Method:** `rust-analyzer/viewRecursiveMemoryLayout`
+
+**Request:** `TextDocumentPositionParams`
+
+**Response:**
+
+```typescript
+export interface RecursiveMemoryLayoutNode = {
+    /// Name of the item, or [ROOT], `.n` for tuples
+    item_name: string;
+    /// Full name of the type (type aliases are ignored)
+    typename: string;
+    /// Size of the type in bytes
+    size: number;
+    /// Alignment of the type in bytes
+    alignment: number;
+    /// Offset of the type relative to its parent (or 0 if its the root)
+    offset: number;
+    /// Index of the node's parent (or -1 if its the root)
+    parent_idx: number;
+    /// Index of the node's children (or -1 if it does not have children)
+    children_start: number;
+    /// Number of child nodes (unspecified it does not have children)
+    children_len: number;
+};
+
+export interface RecursiveMemoryLayout = {
+    nodes: RecursiveMemoryLayoutNode[];
+};
+```
+
+Returns a vector of nodes representing items in the datatype as a tree, `RecursiveMemoryLayout::nodes[0]` is the root node.
+
+If `RecursiveMemoryLayout::nodes::length == 0` we could not find a suitable type.
+
+Generic Types do not give anything because they are incomplete. Fully specified generic types do not give anything if they are selected directly but do work when a child of other types [this is consistent with other behavior](https://github.com/rust-lang/rust-analyzer/issues/15010).
+
+### Unresolved questions:
+
+- How should enums/unions be represented? currently they do not produce any children because they have multiple distinct sets of children.
+- Should niches be represented? currently they are not reported.
+- A visual representation of the memory layout is not specified, see the provided implementation for an example, however it may not translate well to terminal based editors or other such things.
diff --git a/src/tools/rust-analyzer/docs/dev/style.md b/src/tools/rust-analyzer/docs/dev/style.md
index d2a03fba40d..786127639ce 100644
--- a/src/tools/rust-analyzer/docs/dev/style.md
+++ b/src/tools/rust-analyzer/docs/dev/style.md
@@ -869,6 +869,19 @@ type   -> ty
 
 **Rationale:** consistency.
 
+## Error Handling Trivia
+
+Use `anyhow::Result` rather than just `Result`.
+
+**Rationale:** makes it immediately clear what result that is.
+
+Use `anyhow::format_err!` rather than `anyhow::anyhow`.
+
+**Rationale:** consistent, boring, avoids stuttering.
+
+There's no specific guidance on the formatting of error messages, see [anyhow/#209](https://github.com/dtolnay/anyhow/issues/209).
+Do not end error and context messages with `.` though. 
+
 ## Early Returns
 
 Do use early returns
diff --git a/src/tools/rust-analyzer/docs/user/manual.adoc b/src/tools/rust-analyzer/docs/user/manual.adoc
index b5c095fd9d8..31035c4b729 100644
--- a/src/tools/rust-analyzer/docs/user/manual.adoc
+++ b/src/tools/rust-analyzer/docs/user/manual.adoc
@@ -64,22 +64,8 @@ You can install the latest release of the plugin from
 https://marketplace.visualstudio.com/items?itemName=rust-lang.rust-analyzer[the marketplace].
 
 Note that the plugin may cause conflicts with the
-https://marketplace.visualstudio.com/items?itemName=rust-lang.rust[official Rust plugin].
-It is recommended to disable the Rust plugin when using the rust-analyzer extension.
-
-By default, the plugin will prompt you to download the matching version of the server as well:
-
-image::https://user-images.githubusercontent.com/9021944/75067008-17502500-54ba-11ea-835a-f92aac50e866.png[]
-
-[NOTE]
-====
-To disable this notification put the following to `settings.json`
-
-[source,json]
-----
-{ "rust-analyzer.updates.askBeforeDownload": false }
-----
-====
+https://marketplace.visualstudio.com/items?itemName=rust-lang.rust[previous official Rust plugin].
+The latter is no longer maintained and should be uninstalled.
 
 The server binary is stored in the extension install directory, which starts with `rust-lang.rust-analyzer-` and is located under:
 
@@ -141,6 +127,9 @@ If you're not using Code, you can compile and install only the LSP server:
 $ cargo xtask install --server
 ----
 
+Make sure that `.cargo/bin` is in `$PATH` and precedes paths where `rust-analyzer` may also be installed.
+Specifically, `rustup` includes a proxy called `rust-analyzer`, which can cause problems if you're planning to use a source build or even a downloaded binary.
+
 === rust-analyzer Language Server Binary
 
 Other editors generally require the `rust-analyzer` binary to be in `$PATH`.
@@ -280,12 +269,12 @@ Also see the https://emacs-lsp.github.io/lsp-mode/page/lsp-rust-analyzer/[rust-a
 
 Note the excellent https://robert.kra.hn/posts/2021-02-07_rust-with-emacs/[guide] from https://github.com/rksm[@rksm] on how to set-up Emacs for Rust development with LSP mode and several other packages.
 
-=== Vim/NeoVim
+=== Vim/Neovim
 
 Prerequisites: You have installed the <<rust-analyzer-language-server-binary,`rust-analyzer` binary>>.
 Not needed if the extension can install/update it on its own, coc-rust-analyzer is one example.
 
-There are several LSP client implementations for vim or neovim:
+There are several LSP client implementations for Vim or Neovim:
 
 ==== coc-rust-analyzer
 
@@ -308,7 +297,7 @@ Note: for code actions, use `coc-codeaction-cursor` and `coc-codeaction-selected
    https://github.com/autozimu/LanguageClient-neovim[here]
    * The GitHub project wiki has extra tips on configuration
 
-2. Configure by adding this to your vim/neovim config file (replacing the existing Rust-specific line if it exists):
+2. Configure by adding this to your Vim/Neovim config file (replacing the existing Rust-specific line if it exists):
 +
 [source,vim]
 ----
@@ -335,7 +324,7 @@ let g:ale_linters = {'rust': ['analyzer']}
 
 ==== nvim-lsp
 
-NeoVim 0.5 has built-in language server support.
+Neovim 0.5 has built-in language server support.
 For a quick start configuration of rust-analyzer, use https://github.com/neovim/nvim-lspconfig#rust_analyzer[neovim/nvim-lspconfig].
 Once `neovim/nvim-lspconfig` is installed, use `+lua require'lspconfig'.rust_analyzer.setup({})+` in your `init.vim`.
 
@@ -376,7 +365,7 @@ EOF
 
 See https://sharksforarms.dev/posts/neovim-rust/ for more tips on getting started.
 
-Check out https://github.com/simrat39/rust-tools.nvim for a batteries included rust-analyzer setup for neovim.
+Check out https://github.com/simrat39/rust-tools.nvim for a batteries included rust-analyzer setup for Neovim.
 
 ==== vim-lsp
 
@@ -933,17 +922,17 @@ For example:
 More about `when` clause contexts https://code.visualstudio.com/docs/getstarted/keybindings#_when-clause-contexts[here].
 
 ==== Setting runnable environment variables
-You can use "rust-analyzer.runnableEnv" setting to define runnable environment-specific substitution variables.
+You can use "rust-analyzer.runnables.extraEnv" setting to define runnable environment-specific substitution variables.
 The simplest way for all runnables in a bunch:
 ```jsonc
-"rust-analyzer.runnableEnv": {
+"rust-analyzer.runnables.extraEnv": {
     "RUN_SLOW_TESTS": "1"
 }
 ```
 
 Or it is possible to specify vars more granularly:
 ```jsonc
-"rust-analyzer.runnableEnv": [
+"rust-analyzer.runnables.extraEnv": [
     {
         // "mask": null, // null mask means that this rule will be applied for all runnables
         env: {