Merge commit '61eb38aeda6cb54b93b872bf503d70084c4d621c' into clippyup

4 files changed, 435 insertions, 0 deletions

diff --git a/clippy_dev/src/setup/git_hook.rs b/clippy_dev/src/setup/git_hook.rs
new file mode 100644
index 00000000000..3fbb77d5923
--- /dev/null
+++ b/clippy_dev/src/setup/git_hook.rs
@@ -0,0 +1,85 @@
+use std::fs;
+use std::path::Path;
+
+use super::verify_inside_clippy_dir;
+
+/// Rusts setup uses `git rev-parse --git-common-dir` to get the root directory of the repo.
+/// I've decided against this for the sake of simplicity and to make sure that it doesn't install
+/// the hook if `clippy_dev` would be used in the rust tree. The hook also references this tool
+/// for formatting and should therefor only be used in a normal clone of clippy
+const REPO_GIT_DIR: &str = ".git";
+const HOOK_SOURCE_FILE: &str = "util/etc/pre-commit.sh";
+const HOOK_TARGET_FILE: &str = ".git/hooks/pre-commit";
+
+pub fn install_hook(force_override: bool) {
+    if !check_precondition(force_override) {
+        return;
+    }
+
+    // So a little bit of a funny story. Git on unix requires the pre-commit file
+    // to have the `execute` permission to be set. The Rust functions for modifying
+    // these flags doesn't seem to work when executed with normal user permissions.
+    //
+    // However, there is a little hack that is also being used by Rust itself in their
+    // setup script. Git saves the `execute` flag when syncing files. This means
+    // that we can check in a file with execution permissions and the sync it to create
+    // a file with the flag set. We then copy this file here. The copy function will also
+    // include the `execute` permission.
+    match fs::copy(HOOK_SOURCE_FILE, HOOK_TARGET_FILE) {
+        Ok(_) => {
+            println!("info: the hook can be removed with `cargo dev remove git-hook`");
+            println!("git hook successfully installed");
+        },
+        Err(err) => eprintln!(
+            "error: unable to copy `{}` to `{}` ({})",
+            HOOK_SOURCE_FILE, HOOK_TARGET_FILE, err
+        ),
+    }
+}
+
+fn check_precondition(force_override: bool) -> bool {
+    if !verify_inside_clippy_dir() {
+        return false;
+    }
+
+    // Make sure that we can find the git repository
+    let git_path = Path::new(REPO_GIT_DIR);
+    if !git_path.exists() || !git_path.is_dir() {
+        eprintln!("error: clippy_dev was unable to find the `.git` directory");
+        return false;
+    }
+
+    // Make sure that we don't override an existing hook by accident
+    let path = Path::new(HOOK_TARGET_FILE);
+    if path.exists() {
+        if force_override {
+            return delete_git_hook_file(path);
+        }
+
+        eprintln!("error: there is already a pre-commit hook installed");
+        println!("info: use the `--force-override` flag to override the existing hook");
+        return false;
+    }
+
+    true
+}
+
+pub fn remove_hook() {
+    let path = Path::new(HOOK_TARGET_FILE);
+    if path.exists() {
+        if delete_git_hook_file(path) {
+            println!("git hook successfully removed");
+        }
+    } else {
+        println!("no pre-commit hook was found");
+    }
+}
+
+fn delete_git_hook_file(path: &Path) -> bool {
+    if let Err(err) = fs::remove_file(path) {
+        eprintln!("error: unable to delete existing pre-commit git hook ({})", err);
+        false
+    } else {
+        true
+    }
+}
diff --git a/clippy_dev/src/setup/intellij.rs b/clippy_dev/src/setup/intellij.rs
new file mode 100644
index 00000000000..bf741e6d121
--- /dev/null
+++ b/clippy_dev/src/setup/intellij.rs
@@ -0,0 +1,223 @@
+use std::fs;
+use std::fs::File;
+use std::io::prelude::*;
+use std::path::{Path, PathBuf};
+
+// This module takes an absolute path to a rustc repo and alters the dependencies to point towards
+// the respective rustc subcrates instead of using extern crate xyz.
+// This allows IntelliJ to analyze rustc internals and show proper information inside Clippy
+// code. See https://github.com/rust-lang/rust-clippy/issues/5514 for details
+
+const RUSTC_PATH_SECTION: &str = "[target.'cfg(NOT_A_PLATFORM)'.dependencies]";
+const DEPENDENCIES_SECTION: &str = "[dependencies]";
+
+const CLIPPY_PROJECTS: &[ClippyProjectInfo] = &[
+    ClippyProjectInfo::new("root", "Cargo.toml", "src/driver.rs"),
+    ClippyProjectInfo::new("clippy_lints", "clippy_lints/Cargo.toml", "clippy_lints/src/lib.rs"),
+    ClippyProjectInfo::new("clippy_utils", "clippy_utils/Cargo.toml", "clippy_utils/src/lib.rs"),
+];
+
+/// Used to store clippy project information to later inject the dependency into.
+struct ClippyProjectInfo {
+    /// Only used to display information to the user
+    name: &'static str,
+    cargo_file: &'static str,
+    lib_rs_file: &'static str,
+}
+
+impl ClippyProjectInfo {
+    const fn new(name: &'static str, cargo_file: &'static str, lib_rs_file: &'static str) -> Self {
+        Self {
+            name,
+            cargo_file,
+            lib_rs_file,
+        }
+    }
+}
+
+pub fn setup_rustc_src(rustc_path: &str) {
+    let rustc_source_dir = match check_and_get_rustc_dir(rustc_path) {
+        Ok(path) => path,
+        Err(_) => return,
+    };
+
+    for project in CLIPPY_PROJECTS {
+        if inject_deps_into_project(&rustc_source_dir, project).is_err() {
+            return;
+        }
+    }
+
+    println!("info: the source paths can be removed again with `cargo dev remove intellij`");
+}
+
+fn check_and_get_rustc_dir(rustc_path: &str) -> Result<PathBuf, ()> {
+    let mut path = PathBuf::from(rustc_path);
+
+    if path.is_relative() {
+        match path.canonicalize() {
+            Ok(absolute_path) => {
+                println!("info: the rustc path was resolved to: `{}`", absolute_path.display());
+                path = absolute_path;
+            },
+            Err(err) => {
+                eprintln!("error: unable to get the absolute path of rustc ({})", err);
+                return Err(());
+            },
+        };
+    }
+
+    let path = path.join("compiler");
+    println!("info: looking for compiler sources at: {}", path.display());
+
+    if !path.exists() {
+        eprintln!("error: the given path does not exist");
+        return Err(());
+    }
+
+    if !path.is_dir() {
+        eprintln!("error: the given path is not a directory");
+        return Err(());
+    }
+
+    Ok(path)
+}
+
+fn inject_deps_into_project(rustc_source_dir: &Path, project: &ClippyProjectInfo) -> Result<(), ()> {
+    let cargo_content = read_project_file(project.cargo_file)?;
+    let lib_content = read_project_file(project.lib_rs_file)?;
+
+    if inject_deps_into_manifest(rustc_source_dir, project.cargo_file, &cargo_content, &lib_content).is_err() {
+        eprintln!(
+            "error: unable to inject dependencies into {} with the Cargo file {}",
+            project.name, project.cargo_file
+        );
+        Err(())
+    } else {
+        Ok(())
+    }
+}
+
+/// `clippy_dev` expects to be executed in the root directory of Clippy. This function
+/// loads the given file or returns an error. Having it in this extra function ensures
+/// that the error message looks nice.
+fn read_project_file(file_path: &str) -> Result<String, ()> {
+    let path = Path::new(file_path);
+    if !path.exists() {
+        eprintln!("error: unable to find the file `{}`", file_path);
+        return Err(());
+    }
+
+    match fs::read_to_string(path) {
+        Ok(content) => Ok(content),
+        Err(err) => {
+            eprintln!("error: the file `{}` could not be read ({})", file_path, err);
+            Err(())
+        },
+    }
+}
+
+fn inject_deps_into_manifest(
+    rustc_source_dir: &Path,
+    manifest_path: &str,
+    cargo_toml: &str,
+    lib_rs: &str,
+) -> std::io::Result<()> {
+    // do not inject deps if we have already done so
+    if cargo_toml.contains(RUSTC_PATH_SECTION) {
+        eprintln!(
+            "warn: dependencies are already setup inside {}, skipping file",
+            manifest_path
+        );
+        return Ok(());
+    }
+
+    let extern_crates = lib_rs
+        .lines()
+        // only take dependencies starting with `rustc_`
+        .filter(|line| line.starts_with("extern crate rustc_"))
+        // we have something like "extern crate foo;", we only care about the "foo"
+        // extern crate rustc_middle;
+        //              ^^^^^^^^^^^^
+        .map(|s| &s[13..(s.len() - 1)]);
+
+    let new_deps = extern_crates.map(|dep| {
+        // format the dependencies that are going to be put inside the Cargo.toml
+        format!(
+            "{dep} = {{ path = \"{source_path}/{dep}\" }}\n",
+            dep = dep,
+            source_path = rustc_source_dir.display()
+        )
+    });
+
+    // format a new [dependencies]-block with the new deps we need to inject
+    let mut all_deps = String::from("[target.'cfg(NOT_A_PLATFORM)'.dependencies]\n");
+    new_deps.for_each(|dep_line| {
+        all_deps.push_str(&dep_line);
+    });
+    all_deps.push_str("\n[dependencies]\n");
+
+    // replace "[dependencies]" with
+    // [dependencies]
+    // dep1 = { path = ... }
+    // dep2 = { path = ... }
+    // etc
+    let new_manifest = cargo_toml.replacen("[dependencies]\n", &all_deps, 1);
+
+    // println!("{}", new_manifest);
+    let mut file = File::create(manifest_path)?;
+    file.write_all(new_manifest.as_bytes())?;
+
+    println!("info: successfully setup dependencies inside {}", manifest_path);
+
+    Ok(())
+}
+
+pub fn remove_rustc_src() {
+    for project in CLIPPY_PROJECTS {
+        remove_rustc_src_from_project(project);
+    }
+}
+
+fn remove_rustc_src_from_project(project: &ClippyProjectInfo) -> bool {
+    let mut cargo_content = if let Ok(content) = read_project_file(project.cargo_file) {
+        content
+    } else {
+        return false;
+    };
+    let section_start = if let Some(section_start) = cargo_content.find(RUSTC_PATH_SECTION) {
+        section_start
+    } else {
+        println!(
+            "info: dependencies could not be found in `{}` for {}, skipping file",
+            project.cargo_file, project.name
+        );
+        return true;
+    };
+
+    let end_point = if let Some(end_point) = cargo_content.find(DEPENDENCIES_SECTION) {
+        end_point
+    } else {
+        eprintln!(
+            "error: the end of the rustc dependencies section could not be found in `{}`",
+            project.cargo_file
+        );
+        return false;
+    };
+
+    cargo_content.replace_range(section_start..end_point, "");
+
+    match File::create(project.cargo_file) {
+        Ok(mut file) => {
+            file.write_all(cargo_content.as_bytes()).unwrap();
+            println!("info: successfully removed dependencies inside {}", project.cargo_file);
+            true
+        },
+        Err(err) => {
+            eprintln!(
+                "error: unable to open file `{}` to remove rustc dependencies for {} ({})",
+                project.cargo_file, project.name, err
+            );
+            false
+        },
+    }
+}
diff --git a/clippy_dev/src/setup/mod.rs b/clippy_dev/src/setup/mod.rs
new file mode 100644
index 00000000000..a1e4dd103b8
--- /dev/null
+++ b/clippy_dev/src/setup/mod.rs
@@ -0,0 +1,23 @@
+pub mod git_hook;
+pub mod intellij;
+pub mod vscode;
+
+use std::path::Path;
+
+const CLIPPY_DEV_DIR: &str = "clippy_dev";
+
+/// This function verifies that the tool is being executed in the clippy directory.
+/// This is useful to ensure that setups only modify Clippys resources. The verification
+/// is done by checking that `clippy_dev` is a sub directory of the current directory.
+///
+/// It will print an error message and return `false` if the directory could not be
+/// verified.
+fn verify_inside_clippy_dir() -> bool {
+    let path = Path::new(CLIPPY_DEV_DIR);
+    if path.exists() && path.is_dir() {
+        true
+    } else {
+        eprintln!("error: unable to verify that the working directory is clippys directory");
+        false
+    }
+}
diff --git a/clippy_dev/src/setup/vscode.rs b/clippy_dev/src/setup/vscode.rs
new file mode 100644
index 00000000000..d59001b2c66
--- /dev/null
+++ b/clippy_dev/src/setup/vscode.rs
@@ -0,0 +1,104 @@
+use std::fs;
+use std::path::Path;
+
+use super::verify_inside_clippy_dir;
+
+const VSCODE_DIR: &str = ".vscode";
+const TASK_SOURCE_FILE: &str = "util/etc/vscode-tasks.json";
+const TASK_TARGET_FILE: &str = ".vscode/tasks.json";
+
+pub fn install_tasks(force_override: bool) {
+    if !check_install_precondition(force_override) {
+        return;
+    }
+
+    match fs::copy(TASK_SOURCE_FILE, TASK_TARGET_FILE) {
+        Ok(_) => {
+            println!("info: the task file can be removed with `cargo dev remove vscode-tasks`");
+            println!("vscode tasks successfully installed");
+        },
+        Err(err) => eprintln!(
+            "error: unable to copy `{}` to `{}` ({})",
+            TASK_SOURCE_FILE, TASK_TARGET_FILE, err
+        ),
+    }
+}
+
+fn check_install_precondition(force_override: bool) -> bool {
+    if !verify_inside_clippy_dir() {
+        return false;
+    }
+
+    let vs_dir_path = Path::new(VSCODE_DIR);
+    if vs_dir_path.exists() {
+        // verify the target will be valid
+        if !vs_dir_path.is_dir() {
+            eprintln!("error: the `.vscode` path exists but seems to be a file");
+            return false;
+        }
+
+        // make sure that we don't override any existing tasks by accident
+        let path = Path::new(TASK_TARGET_FILE);
+        if path.exists() {
+            if force_override {
+                return delete_vs_task_file(path);
+            }
+
+            eprintln!(
+                "error: there is already a `task.json` file inside the `{}` directory",
+                VSCODE_DIR
+            );
+            println!("info: use the `--force-override` flag to override the existing `task.json` file");
+            return false;
+        }
+    } else {
+        match fs::create_dir(vs_dir_path) {
+            Ok(_) => {
+                println!("info: created `{}` directory for clippy", VSCODE_DIR);
+            },
+            Err(err) => {
+                eprintln!(
+                    "error: the task target directory `{}` could not be created ({})",
+                    VSCODE_DIR, err
+                );
+            },
+        }
+    }
+
+    true
+}
+
+pub fn remove_tasks() {
+    let path = Path::new(TASK_TARGET_FILE);
+    if path.exists() {
+        if delete_vs_task_file(path) {
+            try_delete_vs_directory_if_empty();
+            println!("vscode tasks successfully removed");
+        }
+    } else {
+        println!("no vscode tasks were found");
+    }
+}
+
+fn delete_vs_task_file(path: &Path) -> bool {
+    if let Err(err) = fs::remove_file(path) {
+        eprintln!("error: unable to delete the existing `tasks.json` file ({})", err);
+        return false;
+    }
+
+    true
+}
+
+/// This function will try to delete the `.vscode` directory if it's empty.
+/// It may fail silently.
+fn try_delete_vs_directory_if_empty() {
+    let path = Path::new(VSCODE_DIR);
+    if path.read_dir().map_or(false, |mut iter| iter.next().is_none()) {
+        // The directory is empty. We just try to delete it but allow a silence
+        // fail as an empty `.vscode` directory is still valid
+        let _silence_result = fs::remove_dir(path);
+    } else {
+        // The directory is not empty or could not be read. Either way don't take
+        // any further actions
+    }
+}