Move find_all_ret_expressions into utils

rust-lang · Oct 6, 2020 · c4e24c8 · c4e24c8
1 parent 5ae1e97
commit c4e24c8
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Showing 4 changed files with 133 additions and 250 deletions.
diff --git a/clippy_lints/src/methods/bind_instead_of_map.rs b/clippy_lints/src/methods/bind_instead_of_map.rs
@@ -1,14 +1,12 @@
 use super::{contains_return, BIND_INSTEAD_OF_MAP};
 use crate::utils::{
     in_macro, match_qpath, match_type, method_calls, multispan_sugg_with_applicability, paths, remove_blocks, snippet,
-    snippet_with_macro_callsite, span_lint_and_sugg, span_lint_and_then,
+    snippet_with_macro_callsite, span_lint_and_sugg, span_lint_and_then, visitors::find_all_ret_expressions,
 };
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
-use rustc_hir::intravisit::{self, Visitor};
 use rustc_lint::LateContext;
-use rustc_middle::hir::map::Map;
 use rustc_span::Span;
 
 pub(crate) struct OptionAndThenSome;
@@ -186,124 +184,3 @@ pub(crate) trait BindInsteadOfMap {
         }
     }
 }
-
-/// returns `true` if expr contains match expr desugared from try
-fn contains_try(expr: &hir::Expr<'_>) -> bool {
-    struct TryFinder {
-        found: bool,
-    }
-
-    impl<'hir> intravisit::Visitor<'hir> for TryFinder {
-        type Map = Map<'hir>;
-
-        fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {
-            intravisit::NestedVisitorMap::None
-        }
-
-        fn visit_expr(&mut self, expr: &'hir hir::Expr<'hir>) {
-            if self.found {
-                return;
-            }
-            match expr.kind {
-                hir::ExprKind::Match(_, _, hir::MatchSource::TryDesugar) => self.found = true,
-                _ => intravisit::walk_expr(self, expr),
-            }
-        }
-    }
-
-    let mut visitor = TryFinder { found: false };
-    visitor.visit_expr(expr);
-    visitor.found
-}
-
-fn find_all_ret_expressions<'hir, F>(_cx: &LateContext<'_>, expr: &'hir hir::Expr<'hir>, callback: F) -> bool
-where
-    F: FnMut(&'hir hir::Expr<'hir>) -> bool,
-{
-    struct RetFinder<F> {
-        in_stmt: bool,
-        failed: bool,
-        cb: F,
-    }
-
-    struct WithStmtGuarg<'a, F> {
-        val: &'a mut RetFinder<F>,
-        prev_in_stmt: bool,
-    }
-
-    impl<F> RetFinder<F> {
-        fn inside_stmt(&mut self, in_stmt: bool) -> WithStmtGuarg<'_, F> {
-            let prev_in_stmt = std::mem::replace(&mut self.in_stmt, in_stmt);
-            WithStmtGuarg {
-                val: self,
-                prev_in_stmt,
-            }
-        }
-    }
-
-    impl<F> std::ops::Deref for WithStmtGuarg<'_, F> {
-        type Target = RetFinder<F>;
-
-        fn deref(&self) -> &Self::Target {
-            self.val
-        }
-    }
-
-    impl<F> std::ops::DerefMut for WithStmtGuarg<'_, F> {
-        fn deref_mut(&mut self) -> &mut Self::Target {
-            self.val
-        }
-    }
-
-    impl<F> Drop for WithStmtGuarg<'_, F> {
-        fn drop(&mut self) {
-            self.val.in_stmt = self.prev_in_stmt;
-        }
-    }
-
-    impl<'hir, F: FnMut(&'hir hir::Expr<'hir>) -> bool> intravisit::Visitor<'hir> for RetFinder<F> {
-        type Map = Map<'hir>;
-
-        fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {
-            intravisit::NestedVisitorMap::None
-        }
-
-        fn visit_stmt(&mut self, stmt: &'hir hir::Stmt<'_>) {
-            intravisit::walk_stmt(&mut *self.inside_stmt(true), stmt)
-        }
-
-        fn visit_expr(&mut self, expr: &'hir hir::Expr<'_>) {
-            if self.failed {
-                return;
-            }
-            if self.in_stmt {
-                match expr.kind {
-                    hir::ExprKind::Ret(Some(expr)) => self.inside_stmt(false).visit_expr(expr),
-                    _ => intravisit::walk_expr(self, expr),
-                }
-            } else {
-                match expr.kind {
-                    hir::ExprKind::Match(cond, arms, _) => {
-                        self.inside_stmt(true).visit_expr(cond);
-                        for arm in arms {
-                            self.visit_expr(arm.body);
-                        }
-                    },
-                    hir::ExprKind::Block(..) => intravisit::walk_expr(self, expr),
-                    hir::ExprKind::Ret(Some(expr)) => self.visit_expr(expr),
-                    _ => self.failed |= !(self.cb)(expr),
-                }
-            }
-        }
-    }
-
-    !contains_try(expr) && {
-        let mut ret_finder = RetFinder {
-            in_stmt: false,
-            failed: false,
-            cb: callback,
-        };
-        ret_finder.visit_expr(expr);
-        !ret_finder.failed
-    }
-}
diff --git a/clippy_lints/src/unnecessary_wrap.rs b/clippy_lints/src/unnecessary_wrap.rs
@@ -1,10 +1,13 @@
-use crate::utils::{is_type_diagnostic_item, match_qpath, paths, return_ty, snippet, span_lint_and_then};
+use crate::utils::{
+    is_type_diagnostic_item, match_qpath, paths, return_ty, snippet, span_lint_and_then,
+    visitors::find_all_ret_expressions,
+};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
-use rustc_hir::intravisit::{FnKind, Visitor};
+use rustc_hir::intravisit::FnKind;
 use rustc_hir::*;
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::{hir::map::Map, ty::subst::GenericArgKind};
+use rustc_middle::ty::subst::GenericArgKind;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::Span;
 
@@ -125,126 +128,3 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryWrap {
         }
     }
 }
-
-// code below is copied from `bind_instead_of_map`
-
-fn find_all_ret_expressions<'hir, F>(_cx: &LateContext<'_>, expr: &'hir Expr<'hir>, callback: F) -> bool
-where
-    F: FnMut(&'hir Expr<'hir>) -> bool,
-{
-    struct RetFinder<F> {
-        in_stmt: bool,
-        failed: bool,
-        cb: F,
-    }
-
-    struct WithStmtGuarg<'a, F> {
-        val: &'a mut RetFinder<F>,
-        prev_in_stmt: bool,
-    }
-
-    impl<F> RetFinder<F> {
-        fn inside_stmt(&mut self, in_stmt: bool) -> WithStmtGuarg<'_, F> {
-            let prev_in_stmt = std::mem::replace(&mut self.in_stmt, in_stmt);
-            WithStmtGuarg {
-                val: self,
-                prev_in_stmt,
-            }
-        }
-    }
-
-    impl<F> std::ops::Deref for WithStmtGuarg<'_, F> {
-        type Target = RetFinder<F>;
-
-        fn deref(&self) -> &Self::Target {
-            self.val
-        }
-    }
-
-    impl<F> std::ops::DerefMut for WithStmtGuarg<'_, F> {
-        fn deref_mut(&mut self) -> &mut Self::Target {
-            self.val
-        }
-    }
-
-    impl<F> Drop for WithStmtGuarg<'_, F> {
-        fn drop(&mut self) {
-            self.val.in_stmt = self.prev_in_stmt;
-        }
-    }
-
-    impl<'hir, F: FnMut(&'hir Expr<'hir>) -> bool> intravisit::Visitor<'hir> for RetFinder<F> {
-        type Map = Map<'hir>;
-
-        fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {
-            intravisit::NestedVisitorMap::None
-        }
-
-        fn visit_stmt(&mut self, stmt: &'hir Stmt<'_>) {
-            intravisit::walk_stmt(&mut *self.inside_stmt(true), stmt)
-        }
-
-        fn visit_expr(&mut self, expr: &'hir Expr<'_>) {
-            if self.failed {
-                return;
-            }
-            if self.in_stmt {
-                match expr.kind {
-                    ExprKind::Ret(Some(expr)) => self.inside_stmt(false).visit_expr(expr),
-                    _ => intravisit::walk_expr(self, expr),
-                }
-            } else {
-                match expr.kind {
-                    ExprKind::Match(cond, arms, _) => {
-                        self.inside_stmt(true).visit_expr(cond);
-                        for arm in arms {
-                            self.visit_expr(arm.body);
-                        }
-                    },
-                    ExprKind::Block(..) => intravisit::walk_expr(self, expr),
-                    ExprKind::Ret(Some(expr)) => self.visit_expr(expr),
-                    _ => self.failed |= !(self.cb)(expr),
-                }
-            }
-        }
-    }
-
-    !contains_try(expr) && {
-        let mut ret_finder = RetFinder {
-            in_stmt: false,
-            failed: false,
-            cb: callback,
-        };
-        ret_finder.visit_expr(expr);
-        !ret_finder.failed
-    }
-}
-
-/// returns `true` if expr contains match expr desugared from try
-fn contains_try(expr: &Expr<'_>) -> bool {
-    struct TryFinder {
-        found: bool,
-    }
-
-    impl<'hir> intravisit::Visitor<'hir> for TryFinder {
-        type Map = Map<'hir>;
-
-        fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {
-            intravisit::NestedVisitorMap::None
-        }
-
-        fn visit_expr(&mut self, expr: &'hir Expr<'hir>) {
-            if self.found {
-                return;
-            }
-            match expr.kind {
-                ExprKind::Match(_, _, MatchSource::TryDesugar) => self.found = true,
-                _ => intravisit::walk_expr(self, expr),
-            }
-        }
-    }
-
-    let mut visitor = TryFinder { found: false };
-    visitor.visit_expr(expr);
-    visitor.found
-}
diff --git a/clippy_lints/src/utils/mod.rs b/clippy_lints/src/utils/mod.rs
@@ -19,6 +19,7 @@ pub mod paths;
 pub mod ptr;
 pub mod sugg;
 pub mod usage;
+pub mod visitors;
 
 pub use self::attrs::*;
 pub use self::diagnostics::*;