Reimplement AbsolutePathBuffer

Author: flip1995

clippy_lints/src/attrs.rs

@@ -352,22 +352,22 @@ fn check_clippy_lint_names(cx: &LateContext<'_, '_>, items: &[NestedMetaItem]) {
     }
 }
 
-fn is_relevant_item(tcx: TyCtxt<'_, '_, '_>, item: &Item) -> bool {
+fn is_relevant_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, item: &Item) -> bool {
     if let ItemKind::Fn(_, _, _, eid) = item.node {
         is_relevant_expr(tcx, tcx.body_tables(eid), &tcx.hir().body(eid).value)
     } else {
         true
     }
 }
 
-fn is_relevant_impl(tcx: TyCtxt<'_, '_, '_>, item: &ImplItem) -> bool {
+fn is_relevant_impl<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, item: &ImplItem) -> bool {
     match item.node {
         ImplItemKind::Method(_, eid) => is_relevant_expr(tcx, tcx.body_tables(eid), &tcx.hir().body(eid).value),
         _ => false,
     }
 }
 
-fn is_relevant_trait(tcx: TyCtxt<'_, '_, '_>, item: &TraitItem) -> bool {
+fn is_relevant_trait<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, item: &TraitItem) -> bool {
     match item.node {
         TraitItemKind::Method(_, TraitMethod::Required(_)) => true,
         TraitItemKind::Method(_, TraitMethod::Provided(eid)) => {
@@ -377,7 +377,7 @@ fn is_relevant_trait(tcx: TyCtxt<'_, '_, '_>, item: &TraitItem) -> bool {
     }
 }
 
-fn is_relevant_block(tcx: TyCtxt<'_, '_, '_>, tables: &ty::TypeckTables<'_>, block: &Block) -> bool {
+fn is_relevant_block<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, tables: &ty::TypeckTables<'_>, block: &Block) -> bool {
     if let Some(stmt) = block.stmts.first() {
         match &stmt.node {
             StmtKind::Local(_) => true,
@@ -389,7 +389,7 @@ fn is_relevant_block(tcx: TyCtxt<'_, '_, '_>, tables: &ty::TypeckTables<'_>, blo
     }
 }
 
-fn is_relevant_expr(tcx: TyCtxt<'_, '_, '_>, tables: &ty::TypeckTables<'_>, expr: &Expr) -> bool {
+fn is_relevant_expr<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, tables: &ty::TypeckTables<'_>, expr: &Expr) -> bool {
     match &expr.node {
         ExprKind::Block(block, _) => is_relevant_block(tcx, tables, block),
         ExprKind::Ret(Some(e)) => is_relevant_expr(tcx, tables, e),

clippy_lints/src/consts.rs

@@ -245,7 +245,7 @@ impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> {
                     let def = self.tables.qpath_def(qpath, callee.hir_id);
                     if let Some(def_id) = def.opt_def_id();
                     let def_path = get_def_path(self.tcx, def_id);
-                    if let &["core", "num", impl_ty, "max_value"] = &def_path[..];
+                    if let &["core", "num", impl_ty, "max_value"] = &def_path.iter().map(|s| s.as_str()).collect::<Vec<_>>()[..];
                     then {
                        let value = match impl_ty {
                            "<impl i8>" => i8::max_value() as u128,

clippy_lints/src/fallible_impl_from.rs

@@ -132,7 +132,7 @@ fn lint_impl_body<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, impl_span: Span, impl_it
     }
 }
 
-fn match_type(tcx: ty::TyCtxt<'_, '_, '_>, ty: ty::Ty<'_>, path: &[&str]) -> bool {
+fn match_type<'a, 'tcx>(tcx: ty::TyCtxt<'a, 'tcx, 'tcx>, ty: ty::Ty<'_>, path: &[&str]) -> bool {
     match ty.sty {
         ty::Adt(adt, _) => match_def_path(tcx, adt.did, path),
         _ => false,

clippy_lints/src/lib.rs

@@ -1,6 +1,7 @@
 // error-pattern:cargo-clippy
 
 #![feature(box_syntax)]
+#![feature(never_type)]
 #![feature(rustc_private)]
 #![feature(slice_patterns)]
 #![feature(stmt_expr_attributes)]

clippy_lints/src/types.rs

@@ -12,6 +12,7 @@ use rustc::lint::{in_external_macro, LateContext, LateLintPass, LintArray, LintC
 use rustc::ty::layout::LayoutOf;
 use rustc::ty::{self, InferTy, Ty, TyCtxt, TypeckTables};
 use rustc::{declare_tool_lint, lint_array};
+use rustc::ty::print::Printer;
 use rustc_errors::Applicability;
 use rustc_target::spec::abi::Abi;
 use rustc_typeck::hir_ty_to_ty;
@@ -1135,15 +1136,14 @@ impl LintPass for CastPass {
 
 // Check if the given type is either `core::ffi::c_void` or
 // one of the platform specific `libc::<platform>::c_void` of libc.
-fn is_c_void(tcx: TyCtxt<'_, '_, '_>, ty: Ty<'_>) -> bool {
+fn is_c_void<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'_>) -> bool {
     if let ty::Adt(adt, _) = ty.sty {
-        let mut apb = AbsolutePathBuffer { names: vec![] };
-        tcx.push_item_path(&mut apb, adt.did, false);
+        let names = AbsolutePathBuffer { tcx }.print_def_path(adt.did, &[]).unwrap();
 
-        if apb.names.is_empty() {
+        if names.is_empty() {
             return false;
         }
-        if apb.names[0] == "libc" || apb.names[0] == "core" && *apb.names.last().unwrap() == "c_void" {
+        if names[0] == "libc" || names[0] == "core" && *names.last().unwrap() == "c_void" {
             return true;
         }
     }

clippy_lints/src/utils/mod.rs

@@ -24,6 +24,8 @@ use if_chain::if_chain;
 use matches::matches;
 use rustc::hir;
 use rustc::hir::def::Def;
+use rustc::hir::map::DisambiguatedDefPathData;
+use rustc::hir::def_id::CrateNum;
 use rustc::hir::def_id::{DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
 use rustc::hir::intravisit::{NestedVisitorMap, Visitor};
 use rustc::hir::Node;
@@ -41,7 +43,6 @@ use rustc_errors::Applicability;
 use syntax::ast::{self, LitKind};
 use syntax::attr;
 use syntax::source_map::{Span, DUMMY_SP};
-use syntax::symbol;
 use syntax::symbol::{keywords, Symbol};
 
 use crate::reexport::*;
@@ -97,19 +98,97 @@ pub fn in_macro(span: Span) -> bool {
 /// Used to store the absolute path to a type.
 ///
 /// See `match_def_path` for usage.
-#[derive(Debug)]
-pub struct AbsolutePathBuffer {
-    pub names: Vec<symbol::LocalInternedString>,
+pub struct AbsolutePathBuffer<'a, 'tcx> {
+    pub tcx: TyCtxt<'a, 'tcx, 'tcx>,
 }
 
-impl ty::item_path::ItemPathBuffer for AbsolutePathBuffer {
-    fn root_mode(&self) -> &ty::item_path::RootMode {
-        const ABSOLUTE: &ty::item_path::RootMode = &ty::item_path::RootMode::Absolute;
-        ABSOLUTE
+use rustc::ty::print::Printer;
+
+impl<'tcx> Printer<'tcx, 'tcx> for AbsolutePathBuffer<'_, 'tcx> {
+    type Error = !;
+
+    type Path = Vec<String>;
+    type Region = ();
+    type Type = ();
+    type DynExistential = ();
+
+    fn tcx<'a>(&'a self) -> TyCtxt<'a, 'tcx, 'tcx> {
+        self.tcx
+    }
+
+    fn print_region(
+        self,
+        _region: ty::Region<'_>,
+        ) -> Result<Self::Region, Self::Error> {
+        Ok(())
+    }
+
+    fn print_type(
+        self,
+        _ty: Ty<'tcx>,
+        ) -> Result<Self::Type, Self::Error> {
+        Ok(())
+    }
+
+    fn print_dyn_existential(
+        self,
+        _predicates: &'tcx ty::List<ty::ExistentialPredicate<'tcx>>,
+        ) -> Result<Self::DynExistential, Self::Error> {
+        Ok(())
     }
 
-    fn push(&mut self, text: &str) {
-        self.names.push(symbol::Symbol::intern(text).as_str());
+    fn path_crate(
+        self,
+        cnum: CrateNum,
+        ) -> Result<Self::Path, Self::Error> {
+        Ok(vec![self.tcx.original_crate_name(cnum).to_string()])
+    }
+    fn path_qualified(
+        self,
+        self_ty: Ty<'tcx>,
+        trait_ref: Option<ty::TraitRef<'tcx>>,
+        ) -> Result<Self::Path, Self::Error> {
+        // This shouldn't ever be needed, but just in case:
+        Ok(vec![match trait_ref {
+            Some(trait_ref) => format!("{:?}", trait_ref),
+            None => format!("<{}>", self_ty),
+        }])
+    }
+
+    fn path_append_impl(
+        self,
+        print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
+        _disambiguated_data: &DisambiguatedDefPathData,
+        self_ty: Ty<'tcx>,
+        trait_ref: Option<ty::TraitRef<'tcx>>,
+        ) -> Result<Self::Path, Self::Error> {
+        let mut path = print_prefix(self)?;
+
+        // This shouldn't ever be needed, but just in case:
+        path.push(match trait_ref {
+            Some(trait_ref) => {
+                format!("<impl {} for {}>", trait_ref, self_ty)
+            }
+            None => format!("<impl {}>", self_ty),
+        });
+
+        Ok(path)
+    }
+    fn path_append(
+        self,
+        print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
+        disambiguated_data: &DisambiguatedDefPathData,
+        ) -> Result<Self::Path, Self::Error> {
+        let mut path = print_prefix(self)?;
+        path.push(disambiguated_data.data.as_interned_str().to_string());
+        Ok(path)
+    }
+    fn path_generic_args(
+        self,
+        print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
+        _args: &[Kind<'tcx>],
+        ) -> Result<Self::Path, Self::Error> {
+        print_prefix(self)
     }
 }
 
@@ -121,12 +200,10 @@ impl ty::item_path::ItemPathBuffer for AbsolutePathBuffer {
 /// ```
 ///
 /// See also the `paths` module.
-pub fn match_def_path(tcx: TyCtxt<'_, '_, '_>, def_id: DefId, path: &[&str]) -> bool {
-    let mut apb = AbsolutePathBuffer { names: vec![] };
+pub fn match_def_path<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId, path: &[&str]) -> bool {
+    let names = AbsolutePathBuffer { tcx }.print_def_path(def_id, &[]).unwrap();
 
-    tcx.push_item_path(&mut apb, def_id, false);
-
-    apb.names.len() == path.len() && apb.names.into_iter().zip(path.iter()).all(|(a, &b)| *a == *b)
+    names.len() == path.len() && names.into_iter().zip(path.iter()).all(|(a, &b)| *a == *b)
 }
 
 /// Gets the absolute path of `def_id` as a vector of `&str`.
@@ -138,13 +215,8 @@ pub fn match_def_path(tcx: TyCtxt<'_, '_, '_>, def_id: DefId, path: &[&str]) ->
 ///     // The given `def_id` is that of an `Option` type
 /// };
 /// ```
-pub fn get_def_path(tcx: TyCtxt<'_, '_, '_>, def_id: DefId) -> Vec<&'static str> {
-    let mut apb = AbsolutePathBuffer { names: vec![] };
-    tcx.push_item_path(&mut apb, def_id, false);
-    apb.names
-        .iter()
-        .map(syntax_pos::symbol::LocalInternedString::get)
-        .collect()
+pub fn get_def_path<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> Vec<String> {
+    AbsolutePathBuffer { tcx }.print_def_path(def_id, &[]).unwrap()
 }
 
 /// Checks if type is struct, enum or union type with the given def path.