Auto merge of rust-lang#8112 - Alexendoo:disallowed_methods_primitives, r=flip1995

Allow primitive types in disallowed_methods

Fixes rust-lang#8079

changelog: `disallowed_methods`: Now can disallow methods of primitive types

Author: bors

clippy_lints/src/disallowed_methods.rs

@@ -59,7 +59,7 @@ declare_clippy_lint! {
 #[derive(Clone, Debug)]
 pub struct DisallowedMethods {
     conf_disallowed: Vec<conf::DisallowedMethod>,
-    disallowed: DefIdMap<Option<String>>,
+    disallowed: DefIdMap<usize>,
 }
 
 impl DisallowedMethods {
@@ -75,17 +75,10 @@ impl_lint_pass!(DisallowedMethods => [DISALLOWED_METHODS]);
 
 impl<'tcx> LateLintPass<'tcx> for DisallowedMethods {
     fn check_crate(&mut self, cx: &LateContext<'_>) {
-        for conf in &self.conf_disallowed {
-            let (path, reason) = match conf {
-                conf::DisallowedMethod::Simple(path) => (path, None),
-                conf::DisallowedMethod::WithReason { path, reason } => (
-                    path,
-                    reason.as_ref().map(|reason| format!("{} (from clippy.toml)", reason)),
-                ),
-            };
-            let segs: Vec<_> = path.split("::").collect();
+        for (index, conf) in self.conf_disallowed.iter().enumerate() {
+            let segs: Vec<_> = conf.path().split("::").collect();
             if let Res::Def(_, id) = clippy_utils::path_to_res(cx, &segs) {
-                self.disallowed.insert(id, reason);
+                self.disallowed.insert(id, index);
             }
         }
     }
@@ -95,15 +88,17 @@ impl<'tcx> LateLintPass<'tcx> for DisallowedMethods {
             Some(def_id) => def_id,
             None => return,
         };
-        let reason = match self.disallowed.get(&def_id) {
-            Some(reason) => reason,
+        let conf = match self.disallowed.get(&def_id) {
+            Some(&index) => &self.conf_disallowed[index],
             None => return,
         };
-        let func_path = cx.tcx.def_path_str(def_id);
-        let msg = format!("use of a disallowed method `{}`", func_path);
+        let msg = format!("use of a disallowed method `{}`", conf.path());
         span_lint_and_then(cx, DISALLOWED_METHODS, expr.span, &msg, |diag| {
-            if let Some(reason) = reason {
-                diag.note(reason);
+            if let conf::DisallowedMethod::WithReason {
+                reason: Some(reason), ..
+            } = conf
+            {
+                diag.note(&format!("{} (from clippy.toml)", reason));
             }
         });
     }

clippy_lints/src/utils/conf.rs

@@ -23,6 +23,14 @@ pub enum DisallowedMethod {
     WithReason { path: String, reason: Option<String> },
 }
 
+impl DisallowedMethod {
+    pub fn path(&self) -> &str {
+        let (Self::Simple(path) | Self::WithReason { path, .. }) = self;
+
+        path
+    }
+}
+
 /// A single disallowed type, used by the `DISALLOWED_TYPES` lint.
 #[derive(Clone, Debug, Deserialize)]
 #[serde(untagged)]

clippy_utils/src/lib.rs

@@ -70,16 +70,16 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::unhash::UnhashMap;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::def_id::DefId;
+use rustc_hir::def_id::{CrateNum, DefId};
 use rustc_hir::hir_id::{HirIdMap, HirIdSet};
 use rustc_hir::intravisit::{walk_expr, ErasedMap, FnKind, NestedVisitorMap, Visitor};
 use rustc_hir::itemlikevisit::ItemLikeVisitor;
 use rustc_hir::LangItem::{OptionNone, ResultErr, ResultOk};
 use rustc_hir::{
-    def, Arm, BindingAnnotation, Block, BlockCheckMode, Body, Constness, Destination, Expr, ExprKind, FnDecl,
-    ForeignItem, GenericArgs, HirId, Impl, ImplItem, ImplItemKind, IsAsync, Item, ItemKind, LangItem, Local,
-    MatchSource, Mutability, Node, Param, Pat, PatKind, Path, PathSegment, PrimTy, QPath, Stmt, StmtKind, TraitItem,
-    TraitItemKind, TraitRef, TyKind, UnOp,
+    def, lang_items, Arm, BindingAnnotation, Block, BlockCheckMode, Body, Constness, Destination, Expr, ExprKind,
+    FnDecl, ForeignItem, GenericArgs, HirId, Impl, ImplItem, ImplItemKind, IsAsync, Item, ItemKind, LangItem, Local,
+    MatchSource, Mutability, Node, Param, Pat, PatKind, Path, PathSegment, PrimTy, QPath, Stmt, StmtKind, Target,
+    TraitItem, TraitItemKind, TraitRef, TyKind, UnOp,
 };
 use rustc_lint::{LateContext, Level, Lint, LintContext};
 use rustc_middle::hir::exports::Export;
@@ -525,18 +525,34 @@ pub fn path_to_res(cx: &LateContext<'_>, path: &[&str]) -> Res {
             .iter()
             .find(|item| item.ident.name.as_str() == name)
     }
+    fn find_primitive(tcx: TyCtxt<'_>, name: &str) -> Option<DefId> {
+        if let Some(&(index, Target::Impl)) = lang_items::ITEM_REFS.get(&Symbol::intern(name)) {
+            tcx.lang_items().items()[index]
+        } else {
+            None
+        }
+    }
+    fn find_crate(tcx: TyCtxt<'_>, name: &str) -> Option<DefId> {
+        tcx.crates(())
+            .iter()
+            .find(|&&num| tcx.crate_name(num).as_str() == name)
+            .map(CrateNum::as_def_id)
+    }
 
-    let (krate, first, path) = match *path {
-        [krate, first, ref path @ ..] => (krate, first, path),
+    let (base, first, path) = match *path {
+        [base, first, ref path @ ..] => (base, first, path),
         [primitive] => {
             return PrimTy::from_name(Symbol::intern(primitive)).map_or(Res::Err, Res::PrimTy);
         },
         _ => return Res::Err,
     };
     let tcx = cx.tcx;
-    let crates = tcx.crates(());
-    let krate = try_res!(crates.iter().find(|&&num| tcx.crate_name(num).as_str() == krate));
-    let first = try_res!(item_child_by_name(tcx, krate.as_def_id(), first));
+    let first = try_res!(
+        find_primitive(tcx, base)
+            .or_else(|| find_crate(tcx, base))
+            .and_then(|id| item_child_by_name(tcx, id, first))
+    );
+
     let last = path
         .iter()
         .copied()

tests/ui-toml/toml_disallowed_methods/clippy.toml

@@ -1,6 +1,8 @@
 disallowed-methods = [
     # just a string is shorthand for path only
     "std::iter::Iterator::sum",
+    "f32::clamp",
+    "slice::sort_unstable",
     # can give path and reason with an inline table
     { path = "regex::Regex::is_match", reason = "no matching allowed" },
     # can use an inline table but omit reason

tests/ui-toml/toml_disallowed_methods/conf_disallowed_methods.rs

@@ -7,6 +7,11 @@ fn main() {
     let re = Regex::new(r"ab.*c").unwrap();
     re.is_match("abc");
 
-    let a = vec![1, 2, 3, 4];
+    let mut a = vec![1, 2, 3, 4];
     a.iter().sum::<i32>();
+
+    a.sort_unstable();
+
+    let _ = 2.0f32.clamp(3.0f32, 4.0f32);
+    let _ = 2.0f64.clamp(3.0f64, 4.0f64);
 }

tests/ui-toml/toml_disallowed_methods/conf_disallowed_methods.stderr

@@ -20,5 +20,17 @@ error: use of a disallowed method `std::iter::Iterator::sum`
 LL |     a.iter().sum::<i32>();
    |     ^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 3 previous errors
+error: use of a disallowed method `slice::sort_unstable`
+  --> $DIR/conf_disallowed_methods.rs:13:5
+   |
+LL |     a.sort_unstable();
+   |     ^^^^^^^^^^^^^^^^^
+
+error: use of a disallowed method `f32::clamp`
+  --> $DIR/conf_disallowed_methods.rs:15:13
+   |
+LL |     let _ = 2.0f32.clamp(3.0f32, 4.0f32);
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 5 previous errors