Allow user to specify aliasing model for Miri

compiler/base/cargo-miri-playground

@@ -3,5 +3,5 @@
 set -eu
 
 export MIRI_SYSROOT=~/.cache/miri
-export MIRIFLAGS="-Zmiri-disable-isolation"
+export MIRIFLAGS="${MIRIFLAGS:-} -Zmiri-disable-isolation"
 exec cargo miri run

compiler/base/orchestrator/src/coordinator.rs

@@ -239,6 +239,12 @@ pub enum Channel {
     Nightly,
 }
 
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub enum AliasingModel {
+    Stacked,
+    Tree,
+}
+
 impl Channel {
     #[cfg(test)]
     pub(crate) const ALL: [Self; 3] = [Self::Stable, Self::Beta, Self::Nightly];
@@ -654,6 +660,7 @@ pub struct MiriRequest {
     pub channel: Channel,
     pub crate_type: CrateType,
     pub edition: Edition,
+    pub aliasing_model: AliasingModel,
     pub code: String,
 }
 
@@ -667,10 +674,18 @@ impl LowerRequest for MiriRequest {
     }
 
     fn execute_cargo_request(&self) -> ExecuteCommandRequest {
+        let mut miriflags = Vec::new();
+
+        if matches!(self.aliasing_model, AliasingModel::Tree) {
+            miriflags.push("-Zmiri-tree-borrows");
+        }
+
+        let miriflags = miriflags.join(" ");
+
         ExecuteCommandRequest {
             cmd: "cargo".to_owned(),
             args: vec!["miri-playground".to_owned()],
-            envs: Default::default(),
+            envs: HashMap::from_iter([("MIRIFLAGS".to_owned(), miriflags)]),
             cwd: None,
         }
     }
@@ -3939,6 +3954,7 @@ mod tests {
         channel: Channel::Nightly,
         crate_type: CrateType::Binary,
         edition: Edition::Rust2021,
+        aliasing_model: AliasingModel::Stacked,
         code: String::new(),
     };
 

compiler/build.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -euv -o pipefail
 

compiler/fetch.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -euv -o pipefail
 

tests/spec/features/backtrace_spec.rb

@@ -12,7 +12,7 @@
 
   context "backtraces are enabled" do
     before do
-      in_advanced_options_menu { choose 'enabled' }
+      in_advanced_options_menu { within(:config_option, 'Backtrace') { choose 'On' } }
       within(:header) { click_on("Run") }
     end
 

tests/spec/features/tools_spec.rb

@@ -54,6 +54,30 @@ def code_with_undefined_behavior
     EOF
   end
 
+  scenario "configure Miri for tree borrows" do
+    editor.set code_valid_under_tree_borrows_but_not_stacked_borrows
+    in_advanced_options_menu { choose("tree") }
+    in_tools_menu { click_on("Miri") }
+
+    within(:output, :stdout) do
+      expect(page).to have_content %r{[1, 2]}, wait: 10
+    end
+
+    within(:output, :stderr) do
+      expect(page).to_not have_content %r{Undefined Behavior}
+    end
+  end
+
+  def code_valid_under_tree_borrows_but_not_stacked_borrows
+    <<~EOF
+    fn main() {
+        let val = [1u8, 2];
+        let ptr = &val[0] as *const u8;
+        let _val = unsafe { *ptr.add(1) };
+    }
+    EOF
+  end
+
   scenario "expand macros with the nightly compiler" do
     editor.set code_that_uses_macros
     in_tools_menu { click_on("Expand macros") }

tests/spec/spec_helper.rb

@@ -88,6 +88,12 @@
   css { '[data-test-id = "notification"]' }
 end
 
+Capybara.add_selector(:config_option) do
+  xpath do |label|
+    ".//div[span[contains(., '#{label}')]]"
+  end
+end
+
 RSpec.configure do |config|
   config.after(:example, :js) do
     page.execute_script <<~JS

ui/frontend/.prettierignore

@@ -12,8 +12,10 @@ node_modules
 *.scss
 
 # Slowly migrate files that we've touched
+!AdvancedOptionsMenu.tsx
 !BuildMenu.tsx
 !ButtonSet.tsx
+!ConfigElement.tsx
 !Header.tsx
 !HelpExample.tsx
 !Notifications.tsx

ui/frontend/AdvancedOptionsMenu.tsx

@@ -1,46 +1,83 @@
 import React, { useCallback } from 'react';
 
-import * as config from './reducers/configuration';
 import { Either as EitherConfig, Select as SelectConfig } from './ConfigElement';
+import MenuAside from './MenuAside';
 import MenuGroup from './MenuGroup';
-import * as selectors from './selectors';
-import { Backtrace, Edition } from './types';
 import { useAppDispatch, useAppSelector } from './hooks';
+import * as config from './reducers/configuration';
+import * as selectors from './selectors';
+import { AliasingModel, Backtrace, Edition } from './types';
+
+const MIRI_TREE_BORROWS_URL = 'https://github.com/rust-lang/miri#user-content--zmiri-tree-borrows';
+
+const TreeBorrowAside: React.FC = () => (
+  <MenuAside>
+    Code that is accepted by <a href={MIRI_TREE_BORROWS_URL}>Tree Borrows</a> may be declared
+    undefined behavior in the future.
+  </MenuAside>
+);
 
 const AdvancedOptionsMenu: React.FC = () => {
   const isEditionDefault = useAppSelector(selectors.isEditionDefault);
   const edition = useAppSelector((state) => state.configuration.edition);
-  const isBacktraceSet = useAppSelector(selectors.getBacktraceSet);
+  const isBacktraceDefault = useAppSelector(selectors.isBacktraceDefault);
   const backtrace = useAppSelector((state) => state.configuration.backtrace);
+  const isAliasingModelDefault = useAppSelector(selectors.isAliasingModelDefault);
+  const aliasingModel = useAppSelector((state) => state.configuration.aliasingModel);
 
   const dispatch = useAppDispatch();
 
   const changeEdition = useCallback((e: Edition) => dispatch(config.changeEdition(e)), [dispatch]);
-  const changeBacktrace = useCallback((b: Backtrace) => dispatch(config.changeBacktrace(b)), [dispatch]);
+  const changeBacktrace = useCallback(
+    (b: Backtrace) => dispatch(config.changeBacktrace(b)),
+    [dispatch],
+  );
+  const changeAliasingModel = useCallback(
+    (b: AliasingModel) => dispatch(config.changeAliasingModel(b)),
+    [dispatch],
+  );
 
   return (
-    <MenuGroup title="Advanced options">
-      <SelectConfig
-        name="Edition"
-        value={edition}
-        isNotDefault={!isEditionDefault}
-        onChange={changeEdition}
-      >
-        <option value={Edition.Rust2015}>2015</option>
-        <option value={Edition.Rust2018}>2018</option>
-        <option value={Edition.Rust2021}>2021</option>
-        <option value={Edition.Rust2024}>2024</option>
-      </SelectConfig>
-
-      <EitherConfig
-        id="backtrace"
-        name="Backtrace"
-        a={Backtrace.Disabled}
-        b={Backtrace.Enabled}
-        value={backtrace}
-        isNotDefault={isBacktraceSet}
-        onChange={changeBacktrace} />
-    </MenuGroup>
+    <>
+      <MenuGroup title="Advanced options">
+        <SelectConfig
+          name="Edition"
+          value={edition}
+          isDefault={isEditionDefault}
+          onChange={changeEdition}
+        >
+          <option value={Edition.Rust2015}>2015</option>
+          <option value={Edition.Rust2018}>2018</option>
+          <option value={Edition.Rust2021}>2021</option>
+          <option value={Edition.Rust2024}>2024</option>
+        </SelectConfig>
+
+        <EitherConfig
+          id="backtrace"
+          name="Backtrace"
+          a={Backtrace.Enabled}
+          b={Backtrace.Disabled}
+          aLabel="On"
+          bLabel="Off"
+          value={backtrace}
+          isDefault={isBacktraceDefault}
+          onChange={changeBacktrace}
+        />
+      </MenuGroup>
+
+      <MenuGroup title="Miri">
+        <EitherConfig
+          id="aliasingModel"
+          name="Aliasing model"
+          a={AliasingModel.Stacked}
+          b={AliasingModel.Tree}
+          value={aliasingModel}
+          isDefault={isAliasingModelDefault}
+          onChange={changeAliasingModel}
+          aside={<TreeBorrowAside />}
+        />
+      </MenuGroup>
+    </>
   );
 };
 

ui/frontend/ConfigElement.tsx

@@ -14,37 +14,54 @@ interface EitherProps<T extends string> extends ConfigElementProps {
   onChange: (_: T) => void;
 }
 
-export const Either =
-  <T extends string,>({ id, a, b, aLabel = a, bLabel = b, value, onChange, ...rest }: EitherProps<T>) => (
-    <ConfigElement {...rest}>
-      <div className={styles.toggle}>
-        <input id={`${id}-a`}
-          name={id}
-          value={a}
-          type="radio"
-          checked={value === a}
-          onChange={() => onChange(a as T)} />
-        <label htmlFor={`${id}-a`}>{aLabel}</label>
-        <input id={`${id}-b`}
-          name={id}
-          value={b}
-          type="radio"
-          checked={value === b}
-          onChange={() => onChange(b as T)} />
-        <label htmlFor={`${id}-b`}>{bLabel}</label>
-      </div>
-    </ConfigElement>
-  );
+export const Either = <T extends string>({
+  id,
+  a,
+  b,
+  aLabel = a,
+  bLabel = b,
+  value,
+  onChange,
+  ...rest
+}: EitherProps<T>) => (
+  <ConfigElement {...rest}>
+    <div className={styles.toggle}>
+      <input
+        id={`${id}-a`}
+        name={id}
+        value={a}
+        type="radio"
+        checked={value === a}
+        onChange={() => onChange(a as T)}
+      />
+      <label htmlFor={`${id}-a`}>{aLabel}</label>
+      <input
+        id={`${id}-b`}
+        name={id}
+        value={b}
+        type="radio"
+        checked={value === b}
+        onChange={() => onChange(b as T)}
+      />
+      <label htmlFor={`${id}-b`}>{bLabel}</label>
+    </div>
+  </ConfigElement>
+);
 
 interface SelectProps<T extends string> extends ConfigElementProps {
   children: React.ReactNode;
   value: T;
   onChange: (_: T) => void;
 }
 
-export const Select = <T extends string,>({ value, onChange, children, ...rest }: SelectProps<T>) => (
+export const Select = <T extends string>({
+  value,
+  onChange,
+  children,
+  ...rest
+}: SelectProps<T>) => (
   <ConfigElement {...rest}>
-    <select className={styles.select} value={value} onChange={e => onChange(e.target.value as T)}>
+    <select className={styles.select} value={value} onChange={(e) => onChange(e.target.value as T)}>
       {children}
     </select>
   </ConfigElement>
@@ -53,18 +70,21 @@ export const Select = <T extends string,>({ value, onChange, children, ...rest }
 interface ConfigElementProps {
   children?: React.ReactNode;
   name: string;
-  isNotDefault?: boolean;
-  aside?: JSX.Element,
+  isDefault?: boolean;
+  aside?: JSX.Element;
 }
 
-const ConfigElement: React.FC<ConfigElementProps> = ({ name, isNotDefault, aside, children }) => (
-  <MenuItem>
-    <div className={styles.container}>
-      <span className={isNotDefault ? styles.notDefault : styles.name}>{name}</span>
-      <div className={styles.value}>
-        {children}
+const ConfigElement: React.FC<ConfigElementProps> = ({ name, isDefault, aside, children }) => {
+  const actuallyDefault = isDefault ?? true;
+  const defaultStyle = actuallyDefault ? styles.name : styles.notDefault;
+
+  return (
+    <MenuItem>
+      <div className={styles.container}>
+        <span className={defaultStyle}>{name}</span>
+        <div className={styles.value}>{children}</div>
       </div>
-    </div>
-    {aside}
-  </MenuItem>
-);
+      {aside}
+    </MenuItem>
+  );
+};

ui/frontend/reducers/configuration.ts

@@ -1,6 +1,7 @@
 import { PayloadAction, createSlice } from '@reduxjs/toolkit';
 
 import {
+  AliasingModel,
   AssemblyFlavor,
   Backtrace,
   Channel,
@@ -36,6 +37,7 @@ interface State {
   mode: Mode;
   edition: Edition;
   backtrace: Backtrace;
+  aliasingModel: AliasingModel;
 }
 
 const initialState: State = {
@@ -58,6 +60,7 @@ const initialState: State = {
   mode: Mode.Debug,
   edition: Edition.Rust2024,
   backtrace: Backtrace.Disabled,
+  aliasingModel: AliasingModel.Stacked,
 };
 
 const slice = createSlice({
@@ -76,6 +79,10 @@ const slice = createSlice({
       state.backtrace = action.payload;
     },
 
+    changeAliasingModel: (state, action: PayloadAction<AliasingModel>) => {
+      state.aliasingModel = action.payload;
+    },
+
     changeChannel: (state, action: PayloadAction<Channel>) => {
       state.channel = action.payload;
     },
@@ -146,6 +153,7 @@ export const {
   changeAceTheme,
   changeAssemblyFlavor,
   changeBacktrace,
+  changeAliasingModel,
   changeChannel,
   changeDemangleAssembly,
   changeEdition,