Extract examples from reference and display their results in a dashboard.

.gitignore

@@ -76,3 +76,6 @@ __pycache__/
 src/test/rustdoc-gui/src/**.lock
 
 # Before adding new lines, see the comment at the top.
+/src/test/ref
+/src/tools/dashboard/Cargo.lock
+/src/tools/dashboard/target

Cargo.toml

@@ -49,6 +49,7 @@ exclude = [
   "src/tools/x",
   # stdarch has its own Cargo workspace
   "library/stdarch",
+  "src/tools/dashboard",
 ]
 
 [profile.release.package.compiler_builtins]

scripts/display-dashboard.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0 OR MIT
+
+SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+RUST_DIR=$SCRIPT_DIR/..
+export PATH=$SCRIPT_DIR:$PATH
+
+cargo build --manifest-path src/tools/dashboard/Cargo.toml
+cargo run --manifest-path src/tools/dashboard/Cargo.toml

src/bootstrap/builder.rs

@@ -461,6 +461,7 @@ impl<'a> Builder<'a> {
                 test::SMACK,
                 test::CargoRMC,
                 test::Expected,
+                test::Ref,
                 // Run run-make last, since these won't pass without make on Windows
                 test::RunMake,
             ),

src/bootstrap/test.rs

@@ -1203,6 +1203,8 @@ default_test!(CargoRMC { path: "src/test/cargo-rmc", mode: "cargo-rmc", suite: "
 
 default_test!(Expected { path: "src/test/expected", mode: "expected", suite: "expected" });
 
+default_test!(Ref { path: "src/test/ref", mode: "rmc", suite: "ref" });
+
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 struct Compiletest {
     compiler: Compiler,

src/tools/dashboard/Cargo.toml

@@ -0,0 +1,10 @@
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0 OR MIT
+
+[package]
+name = "dashboard"
+version = "0.1.0"
+edition = "2018"
+
+[dependencies]
+pulldown-cmark = { version = "0.8.0", default-features = false }

src/tools/dashboard/print.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0 OR MIT
+
+# `rustdoc` treats this script as `rustc` and sends code extracted from markdown
+# files to stdin of this script. Instead of compiling the code, this scripts
+# simply copies the contents of stdin to the location where `rustdoc` caches the
+# "compiled" output.
+
+FILE="$6"
+BASE=`basename "$FILE"`
+mkdir -p "$BASE"
+cp "/dev/stdin" "$FILE"

src/tools/dashboard/src/dashboard.rs

@@ -0,0 +1,95 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+//! Data structures representing the dashboard and their utilities.
+
+use std::fmt::{Display, Formatter, Result, Write};
+
+/// This data structure holds the results of running a test or a suite.
+#[derive(Clone, Debug)]
+pub struct Node {
+    pub name: String,
+    pub num_pass: u32,
+    pub num_fail: u32,
+}
+
+impl Node {
+    /// Creates a new test [`Node`].
+    pub fn new(name: String, num_pass: u32, num_fail: u32) -> Node {
+        Node { name, num_pass, num_fail }
+    }
+}
+
+/// Tree data structure representing a confidence dashboard. `children`
+/// represent sub-tests and sub-suites of the current test suite. This tree
+/// structure allows us to collect and display a summary for test results in an
+/// organized manner.
+#[derive(Clone, Debug)]
+pub struct Tree {
+    pub data: Node,
+    pub children: Vec<Tree>,
+}
+
+impl Tree {
+    /// Creates a new [`Tree`] representing a dashboard or a part of it.
+    pub fn new(data: Node, children: Vec<Tree>) -> Tree {
+        Tree { data, children }
+    }
+
+    /// Merges two trees, if their root have equal node names, and returns the
+    /// merged tree.
+    pub fn merge(mut l: Tree, r: Tree) -> Option<Tree> {
+        if l.data.name != r.data.name {
+            return None;
+        }
+        // For each subtree of `r`...
+        for cnr in r.children {
+            // Look for a subtree of `l` with an equal root node name.
+            let index = l.children.iter().position(|cnl| cnl.data.name == cnr.data.name);
+            if let Some(index) = index {
+                // If you find one, merge it with `r`'s subtree.
+                let cnl = l.children.remove(index);
+                l.children.insert(index, Tree::merge(cnl, cnr)?);
+            } else {
+                // Otherwise, `r`'s subtree is new. So, add it to `l`'s
+                // list of subtrees.
+                l.children.push(cnr);
+            }
+        }
+        Some(Tree::new(
+            Node::new(
+                l.data.name,
+                l.data.num_pass + r.data.num_pass,
+                l.data.num_fail + r.data.num_fail,
+            ),
+            l.children,
+        ))
+    }
+
+    /// A helper format function that indents each level of the tree.
+    fn fmt_aux(&self, p: usize, f: &mut Formatter<'_>) -> Result {
+        // Do not print line numbers.
+        if self.children.len() == 0 {
+            return Ok(());
+        }
+        // Write `p` spaces into the formatter.
+        f.write_fmt(format_args!("{:1$}", "", p))?;
+        f.write_str(&self.data.name)?;
+        if self.data.num_pass > 0 {
+            f.write_fmt(format_args!(" ✔️ {}", self.data.num_pass))?;
+        }
+        if self.data.num_fail > 0 {
+            f.write_fmt(format_args!(" ❌ {}", self.data.num_fail))?;
+        }
+        f.write_char('\n')?;
+        for cn in &self.children {
+            cn.fmt_aux(p + 2, f)?;
+        }
+        Ok(())
+    }
+}
+
+impl Display for Tree {
+    fn fmt(&self, f: &mut Formatter<'_>) -> Result {
+        self.fmt_aux(0, f)
+    }
+}

src/tools/dashboard/src/main.rs

@@ -0,0 +1,9 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+mod dashboard;
+mod reference;
+
+fn main() {
+    reference::display_reference_dashboard();
+}