Add a BLACKLISTED_NAME lint

src/blacklisted_name.rs

@@ -0,0 +1,45 @@
+use rustc::lint::*;
+use rustc_front::hir::*;
+use utils::span_lint;
+
+/// **What it does:** This lints about usage of blacklisted names.
+///
+/// **Why is this bad?** These names are usually placeholder names and should be avoided.
+///
+/// **Known problems:** None.
+///
+/// **Example:** `let foo = 3.14;`
+declare_lint! {
+    pub BLACKLISTED_NAME,
+    Warn,
+    "usage of a blacklisted/placeholder name"
+}
+
+#[derive(Clone, Debug)]
+pub struct BlackListedName {
+    blacklist: Vec<String>,
+}
+
+impl BlackListedName {
+    pub fn new(blacklist: Vec<String>) -> BlackListedName {
+        BlackListedName {
+            blacklist: blacklist
+        }
+    }
+}
+
+impl LintPass for BlackListedName {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(BLACKLISTED_NAME)
+    }
+}
+
+impl LateLintPass for BlackListedName {
+    fn check_pat(&mut self, cx: &LateContext, pat: &Pat) {
+        if let PatKind::Ident(_, ref ident, _) = pat.node {
+            if self.blacklist.iter().any(|s| s == &*ident.node.name.as_str()) {
+                span_lint(cx, BLACKLISTED_NAME, pat.span, &format!("use of a blacklisted/placeholder name `{}`", ident.node.name));
+            }
+        }
+    }
+}

src/lib.rs

@@ -48,6 +48,7 @@ pub mod approx_const;
 pub mod array_indexing;
 pub mod attrs;
 pub mod bit_mask;
+pub mod blacklisted_name;
 pub mod block_in_if_condition;
 pub mod collapsible_if;
 pub mod copies;
@@ -204,6 +205,7 @@ pub fn plugin_registrar(reg: &mut Registry) {
     reg.register_late_lint_pass(box overflow_check_conditional::OverflowCheckConditional);
     reg.register_late_lint_pass(box unused_label::UnusedLabel);
     reg.register_late_lint_pass(box new_without_default::NewWithoutDefault);
+    reg.register_late_lint_pass(box blacklisted_name::BlackListedName::new(conf.blacklisted_names));
 
     reg.register_lint_group("clippy_pedantic", vec![
         array_indexing::INDEXING_SLICING,
@@ -236,6 +238,7 @@ pub fn plugin_registrar(reg: &mut Registry) {
         attrs::INLINE_ALWAYS,
         bit_mask::BAD_BIT_MASK,
         bit_mask::INEFFECTIVE_BIT_MASK,
+        blacklisted_name::BLACKLISTED_NAME,
         block_in_if_condition::BLOCK_IN_IF_CONDITION_EXPR,
         block_in_if_condition::BLOCK_IN_IF_CONDITION_STMT,
         collapsible_if::COLLAPSIBLE_IF,