481 lines
19 KiB
Rust
481 lines
19 KiB
Rust
//! A group of attributes that can be attached to Rust code in order
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//! to generate a clippy lint detecting said code automatically.
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#![allow(print_stdout, use_debug)]
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use rustc::lint::*;
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use rustc::hir;
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use rustc::hir::{Expr, QPath, Expr_};
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use rustc::hir::intravisit::{Visitor, NestedVisitorMap};
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use syntax::ast::{self, Attribute, NodeId, LitKind, DUMMY_NODE_ID};
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use syntax::codemap::Span;
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use std::collections::HashMap;
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/// **What it does:** Generates clippy code that detects the offending pattern
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///
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/// **Example:**
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/// ```rust
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/// fn foo() {
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/// // detect the following pattern
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/// #[clippy(author)]
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/// if x == 42 {
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/// // but ignore everything from here on
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/// #![clippy(author = "ignore")]
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/// }
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/// }
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/// ```
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///
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/// prints
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///
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/// ```
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/// if_let_chain!{[
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/// let Expr_::ExprIf(ref cond, ref then, None) = item.node,
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/// let Expr_::ExprBinary(BinOp::Eq, ref left, ref right) = cond.node,
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/// let Expr_::ExprPath(ref path) = left.node,
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/// let Expr_::ExprLit(ref lit) = right.node,
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/// let LitKind::Int(42, _) = lit.node,
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/// ], {
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/// // report your lint here
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/// }}
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/// ```
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declare_lint! {
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pub LINT_AUTHOR,
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Warn,
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"helper for writing lints"
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}
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pub struct Pass;
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impl LintPass for Pass {
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fn get_lints(&self) -> LintArray {
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lint_array!(LINT_AUTHOR)
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}
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}
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fn prelude() {
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println!("if_let_chain!{{[");
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}
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fn done() {
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println!("], {{");
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println!(" // report your lint here");
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println!("}}}}");
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}
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impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
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fn check_item(&mut self, _cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item) {
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if !has_attr(&item.attrs) {
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return;
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}
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prelude();
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PrintVisitor::new("item").visit_item(item);
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done();
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}
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fn check_impl_item(&mut self, _cx: &LateContext<'a, 'tcx>, item: &'tcx hir::ImplItem) {
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if !has_attr(&item.attrs) {
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return;
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}
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prelude();
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PrintVisitor::new("item").visit_impl_item(item);
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done();
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}
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fn check_trait_item(&mut self, _cx: &LateContext<'a, 'tcx>, item: &'tcx hir::TraitItem) {
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if !has_attr(&item.attrs) {
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return;
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}
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prelude();
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PrintVisitor::new("item").visit_trait_item(item);
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done();
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}
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fn check_variant(&mut self, _cx: &LateContext<'a, 'tcx>, var: &'tcx hir::Variant, generics: &hir::Generics) {
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if !has_attr(&var.node.attrs) {
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return;
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}
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prelude();
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PrintVisitor::new("var").visit_variant(var, generics, DUMMY_NODE_ID);
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done();
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}
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fn check_struct_field(&mut self, _cx: &LateContext<'a, 'tcx>, field: &'tcx hir::StructField) {
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if !has_attr(&field.attrs) {
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return;
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}
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prelude();
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PrintVisitor::new("field").visit_struct_field(field);
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done();
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}
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fn check_expr(&mut self, _cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
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if !has_attr(&expr.attrs) {
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return;
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}
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prelude();
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PrintVisitor::new("expr").visit_expr(expr);
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done();
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}
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fn check_arm(&mut self, _cx: &LateContext<'a, 'tcx>, arm: &'tcx hir::Arm) {
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if !has_attr(&arm.attrs) {
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return;
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}
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prelude();
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PrintVisitor::new("arm").visit_arm(arm);
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done();
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}
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fn check_stmt(&mut self, _cx: &LateContext<'a, 'tcx>, stmt: &'tcx hir::Stmt) {
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if !has_attr(stmt.node.attrs()) {
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return;
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}
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prelude();
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PrintVisitor::new("stmt").visit_stmt(stmt);
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done();
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}
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fn check_foreign_item(&mut self, _cx: &LateContext<'a, 'tcx>, item: &'tcx hir::ForeignItem) {
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if !has_attr(&item.attrs) {
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return;
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}
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prelude();
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PrintVisitor::new("item").visit_foreign_item(item);
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done();
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}
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}
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impl PrintVisitor {
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fn new(s: &'static str) -> Self {
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Self {
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ids: HashMap::new(),
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current: s.to_owned(),
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}
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}
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fn next(&mut self, s: &'static str) -> String {
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use std::collections::hash_map::Entry::*;
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match self.ids.entry(s) {
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// already there: start numbering from `1`
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Occupied(mut occ) => {
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let val = occ.get_mut();
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*val += 1;
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format!("{}{}", s, *val)
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},
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// not there: insert and return name as given
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Vacant(vac) => {
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vac.insert(0);
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s.to_owned()
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},
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}
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}
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}
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struct PrintVisitor {
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/// Fields are the current index that needs to be appended to pattern
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/// binding names
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ids: HashMap<&'static str, usize>,
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/// the name that needs to be destructured
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current: String,
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}
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impl<'tcx> Visitor<'tcx> for PrintVisitor {
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fn visit_expr(&mut self, expr: &Expr) {
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print!(" let Expr_::Expr");
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let current = format!("{}.node", self.current);
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match expr.node {
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Expr_::ExprBox(ref inner) => {
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let inner_pat = self.next("inner");
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println!("Box(ref {}) = {},", inner_pat, current);
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self.current = inner_pat;
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self.visit_expr(inner);
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},
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Expr_::ExprArray(ref elements) => {
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let elements_pat = self.next("elements");
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println!("Array(ref {}) = {},", elements_pat, current);
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println!(" {}.len() == {},", elements_pat, elements.len());
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for (i, element) in elements.iter().enumerate() {
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self.current = format!("{}[{}]", elements_pat, i);
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self.visit_expr(element);
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}
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},
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Expr_::ExprCall(ref _func, ref _args) => {
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println!("Call(ref func, ref args) = {},", current);
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println!(" // unimplemented: `ExprCall` is not further destructured at the moment");
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},
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Expr_::ExprMethodCall(ref _method_name, ref _generics, ref _args) => {
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println!("MethodCall(ref method_name, ref generics, ref args) = {},", current);
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println!(" // unimplemented: `ExprMethodCall` is not further destructured at the moment");
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},
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Expr_::ExprTup(ref elements) => {
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let elements_pat = self.next("elements");
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println!("Tup(ref {}) = {},", elements_pat, current);
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println!(" {}.len() == {},", elements_pat, elements.len());
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for (i, element) in elements.iter().enumerate() {
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self.current = format!("{}[{}]", elements_pat, i);
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self.visit_expr(element);
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}
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},
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Expr_::ExprBinary(ref op, ref left, ref right) => {
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let op_pat = self.next("op");
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let left_pat = self.next("left");
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let right_pat = self.next("right");
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println!("Binary(ref {}, ref {}, ref {}) = {},", op_pat, left_pat, right_pat, current);
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println!(" BinOp_::{:?} == {}.node,", op.node, op_pat);
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self.current = left_pat;
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self.visit_expr(left);
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self.current = right_pat;
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self.visit_expr(right);
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},
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Expr_::ExprUnary(ref op, ref inner) => {
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let inner_pat = self.next("inner");
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println!("Unary(UnOp::{:?}, ref {}) = {},", op, inner_pat, current);
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self.current = inner_pat;
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self.visit_expr(inner);
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},
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Expr_::ExprLit(ref lit) => {
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let lit_pat = self.next("lit");
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println!("Lit(ref {}) = {},", lit_pat, current);
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match lit.node {
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LitKind::Bool(val) => println!(" let LitKind::Bool({:?}) = {}.node,", val, lit_pat),
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LitKind::Char(c) => println!(" let LitKind::Char({:?}) = {}.node,", c, lit_pat),
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LitKind::Byte(b) => println!(" let LitKind::Byte({}) = {}.node,", b, lit_pat),
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// FIXME: also check int type
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LitKind::Int(i, _) => println!(" let LitKind::Int({}, _) = {}.node,", i, lit_pat),
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LitKind::Float(..) => println!(" let LitKind::Float(..) = {}.node,", lit_pat),
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LitKind::FloatUnsuffixed(_) => println!(" let LitKind::FloatUnsuffixed(_) = {}.node,", lit_pat),
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LitKind::ByteStr(ref vec) => {
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let vec_pat = self.next("vec");
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println!(" let LitKind::ByteStr(ref {}) = {}.node,", vec_pat, lit_pat);
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println!(" let [{:?}] = **{},", vec, vec_pat);
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},
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LitKind::Str(ref text, _) => {
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let str_pat = self.next("s");
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println!(" let LitKind::Str(ref {}) = {}.node,", str_pat, lit_pat);
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println!(" {}.as_str() == {:?}", str_pat, &*text.as_str())
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},
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}
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},
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Expr_::ExprCast(ref expr, ref _ty) => {
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let cast_pat = self.next("expr");
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println!("Cast(ref {}, _) = {},", cast_pat, current);
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self.current = cast_pat;
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self.visit_expr(expr);
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},
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Expr_::ExprType(ref expr, ref _ty) => {
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let cast_pat = self.next("expr");
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println!("Type(ref {}, _) = {},", cast_pat, current);
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self.current = cast_pat;
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self.visit_expr(expr);
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},
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Expr_::ExprIf(ref cond, ref then, ref opt_else) => {
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let cond_pat = self.next("cond");
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let then_pat = self.next("then");
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if let Some(ref else_) = *opt_else {
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let else_pat = self.next("else_");
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println!("If(ref {}, ref {}, Some(ref {})) = {},", cond_pat, then_pat, else_pat, current);
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self.current = else_pat;
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self.visit_expr(else_);
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} else {
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println!("If(ref {}, ref {}, None) = {},", cond_pat, then_pat, current);
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}
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self.current = cond_pat;
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self.visit_expr(cond);
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self.current = then_pat;
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self.visit_expr(then);
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},
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Expr_::ExprWhile(ref _cond, ref _body, ref _opt_label) => {
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println!("While(ref cond, ref body, ref opt_label) = {},", current);
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println!(" // unimplemented: `ExprWhile` is not further destructured at the moment");
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},
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Expr_::ExprLoop(ref _body, ref _opt_label, ref _desuraging) => {
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println!("Loop(ref body, ref opt_label, ref desugaring) = {},", current);
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println!(" // unimplemented: `ExprLoop` is not further destructured at the moment");
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},
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Expr_::ExprMatch(ref _expr, ref _arms, ref _desugaring) => {
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println!("Match(ref expr, ref arms, ref desugaring) = {},", current);
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println!(" // unimplemented: `ExprMatch` is not further destructured at the moment");
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},
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Expr_::ExprClosure(ref _capture_clause, ref _func, _, _) => {
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println!("Closure(ref capture_clause, ref func, _, _) = {},", current);
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println!(" // unimplemented: `ExprClosure` is not further destructured at the moment");
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},
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Expr_::ExprBlock(ref block) => {
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let block_pat = self.next("block");
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println!("Block(ref {}) = {},", block_pat, current);
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self.current = block_pat;
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self.visit_block(block);
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},
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Expr_::ExprAssign(ref target, ref value) => {
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let target_pat = self.next("target");
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let value_pat = self.next("value");
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println!("Assign(ref {}, ref {}) = {},", target_pat, value_pat, current);
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self.current = target_pat;
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self.visit_expr(target);
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self.current = value_pat;
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self.visit_expr(value);
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},
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Expr_::ExprAssignOp(ref op, ref target, ref value) => {
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let op_pat = self.next("op");
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let target_pat = self.next("target");
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let value_pat = self.next("value");
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println!("AssignOp(ref {}, ref {}, ref {}) = {},", op_pat, target_pat, value_pat, current);
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println!(" BinOp_::{:?} == {}.node,", op.node, op_pat);
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self.current = target_pat;
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self.visit_expr(target);
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self.current = value_pat;
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self.visit_expr(value);
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},
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Expr_::ExprField(ref object, ref field_name) => {
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let obj_pat = self.next("object");
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let field_name_pat = self.next("field_name");
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println!("Field(ref {}, ref {}) = {},", obj_pat, field_name_pat, current);
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println!(" {}.node.as_str() == {:?}", field_name_pat, field_name.node.as_str());
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self.current = obj_pat;
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self.visit_expr(object);
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},
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Expr_::ExprTupField(ref object, ref field_id) => {
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let obj_pat = self.next("object");
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let field_id_pat = self.next("field_id");
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println!("TupField(ref {}, ref {}) = {},", obj_pat, field_id_pat, current);
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println!(" {}.node == {}", field_id_pat, field_id.node);
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self.current = obj_pat;
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self.visit_expr(object);
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},
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Expr_::ExprIndex(ref object, ref index) => {
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let object_pat = self.next("object");
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let index_pat = self.next("index");
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println!("Index(ref {}, ref {}) = {},", object_pat, index_pat, current);
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self.current = object_pat;
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self.visit_expr(object);
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self.current = index_pat;
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self.visit_expr(index);
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},
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Expr_::ExprPath(ref path) => {
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let path_pat = self.next("path");
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println!("Path(ref {}) = {},", path_pat, current);
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self.current = path_pat;
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self.visit_qpath(path, expr.id, expr.span);
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},
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Expr_::ExprAddrOf(mutability, ref inner) => {
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let inner_pat = self.next("inner");
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println!("AddrOf({:?}, ref {}) = {},", mutability, inner_pat, current);
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self.current = inner_pat;
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self.visit_expr(inner);
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},
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Expr_::ExprBreak(ref _destination, ref opt_value) => {
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let destination_pat = self.next("destination");
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if let Some(ref value) = *opt_value {
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let value_pat = self.next("value");
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println!("Break(ref {}, Some(ref {})) = {},", destination_pat, value_pat, current);
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self.current = value_pat;
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self.visit_expr(value);
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} else {
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println!("Break(ref {}, None) = {},", destination_pat, current);
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}
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// FIXME: implement label printing
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},
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Expr_::ExprAgain(ref _destination) => {
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let destination_pat = self.next("destination");
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println!("Again(ref {}) = {},", destination_pat, current);
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// FIXME: implement label printing
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},
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Expr_::ExprRet(ref opt_value) => {
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if let Some(ref value) = *opt_value {
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let value_pat = self.next("value");
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println!("Ret(Some(ref {})) = {},", value_pat, current);
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self.current = value_pat;
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self.visit_expr(value);
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} else {
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println!("Ret(None) = {},", current);
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}
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},
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Expr_::ExprInlineAsm(_, ref _input, ref _output) => {
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println!("InlineAsm(_, ref input, ref output) = {},", current);
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println!(" // unimplemented: `ExprInlineAsm` is not further destructured at the moment");
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},
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Expr_::ExprStruct(ref path, ref fields, ref opt_base) => {
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let path_pat = self.next("path");
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let fields_pat = self.next("fields");
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if let Some(ref base) = *opt_base {
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let base_pat = self.next("base");
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println!(
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"Struct(ref {}, ref {}, Some(ref {})) = {},",
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path_pat,
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fields_pat,
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base_pat,
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current
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);
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self.current = base_pat;
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self.visit_expr(base);
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} else {
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println!("Struct(ref {}, ref {}, None) = {},", path_pat, fields_pat, current);
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}
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self.current = path_pat;
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self.visit_qpath(path, expr.id, expr.span);
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println!(" {}.len() == {},", fields_pat, fields.len());
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println!(" // unimplemented: field checks");
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},
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// FIXME: compute length (needs type info)
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Expr_::ExprRepeat(ref value, _) => {
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let value_pat = self.next("value");
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println!("Repeat(ref {}, _) = {},", value_pat, current);
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println!("// unimplemented: repeat count check");
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self.current = value_pat;
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self.visit_expr(value);
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},
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}
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}
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fn visit_qpath(&mut self, path: &QPath, _: NodeId, _: Span) {
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print!(" match_qpath({}, &[", self.current);
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print_path(path, &mut true);
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println!("]),");
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}
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fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
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NestedVisitorMap::None
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}
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}
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fn has_attr(attrs: &[Attribute]) -> bool {
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attrs.iter().any(|attr| {
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attr.check_name("clippy") &&
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attr.meta_item_list().map_or(false, |list| {
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list.len() == 1 &&
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match list[0].node {
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ast::NestedMetaItemKind::MetaItem(ref it) => it.name == "author",
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ast::NestedMetaItemKind::Literal(_) => false,
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}
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})
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})
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}
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fn print_path(path: &QPath, first: &mut bool) {
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match *path {
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QPath::Resolved(_, ref path) => {
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for segment in &path.segments {
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if *first {
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*first = false;
|
|
} else {
|
|
print!(", ");
|
|
}
|
|
print!("{:?}", segment.name.as_str());
|
|
}
|
|
},
|
|
QPath::TypeRelative(ref ty, ref segment) => {
|
|
match ty.node {
|
|
hir::Ty_::TyPath(ref inner_path) => {
|
|
print_path(inner_path, first);
|
|
if *first {
|
|
*first = false;
|
|
} else {
|
|
print!(", ");
|
|
}
|
|
print!("{:?}", segment.name.as_str());
|
|
},
|
|
ref other => print!("/* unimplemented: {:?}*/", other),
|
|
}
|
|
},
|
|
}
|
|
}
|