Move more functions to utils::higher

Author: mcarton

clippy_lints/src/formatting.rs

@@ -156,7 +156,7 @@ fn check_consecutive_ifs(cx: &EarlyContext, first: &ast::Expr, second: &ast::Exp
     }
 }
 
-/// Match `if` or `else if` expressions and return the `then` and `else` block.
+/// Match `if` or `if let` expressions and return the `then` and `else` block.
 fn unsugar_if(expr: &ast::Expr) -> Option<(&P<ast::Block>, &Option<P<ast::Expr>>)> {
     match expr.node {
         ast::ExprKind::If(_, ref then, ref else_) |

clippy_lints/src/loops.rs

@@ -15,7 +15,7 @@ use syntax::ast;
 
 use utils::{snippet, span_lint, get_parent_expr, match_trait_method, match_type, in_external_macro,
             span_help_and_lint, is_integer_literal, get_enclosing_block, span_lint_and_then, higher,
-            walk_ptrs_ty, recover_for_loop};
+            walk_ptrs_ty};
 use utils::paths;
 
 /// **What it does:** This lint checks for looping over the range of `0..len` of some collection just to get the values by index.
@@ -223,7 +223,7 @@ impl LintPass for Pass {
 
 impl LateLintPass for Pass {
     fn check_expr(&mut self, cx: &LateContext, expr: &Expr) {
-        if let Some((pat, arg, body)) = recover_for_loop(expr) {
+        if let Some((pat, arg, body)) = higher::for_loop(expr) {
             check_for_loop(cx, pat, arg, body, expr);
         }
         // check for `loop { if let {} else break }` that could be `while let`

clippy_lints/src/mut_mut.rs

@@ -2,7 +2,7 @@ use rustc::hir;
 use rustc::hir::intravisit;
 use rustc::lint::*;
 use rustc::ty::{TypeAndMut, TyRef};
-use utils::{in_external_macro, recover_for_loop, span_lint};
+use utils::{higher, in_external_macro, span_lint};
 
 /// **What it does:** This lint checks for instances of `mut mut` references.
 ///
@@ -49,7 +49,7 @@ impl<'a, 'tcx, 'v> intravisit::Visitor<'v> for MutVisitor<'a, 'tcx> {
             return;
         }
 
-        if let Some((_, arg, body)) = recover_for_loop(expr) {
+        if let Some((_, arg, body)) = higher::for_loop(expr) {
             // A `for` loop lowers to:
             // ```rust
             // match ::std::iter::Iterator::next(&mut iter) {

clippy_lints/src/shadow.rs

@@ -5,7 +5,7 @@ use rustc::hir::*;
 use rustc::hir::intravisit::{Visitor, FnKind};
 use std::ops::Deref;
 use syntax::codemap::Span;
-use utils::{is_from_for_desugar, in_external_macro, snippet, span_lint_and_then};
+use utils::{higher, in_external_macro, snippet, span_lint_and_then};
 
 /// **What it does:** This lint checks for bindings that shadow other bindings already in scope, while just changing reference level or mutability.
 ///
@@ -91,7 +91,7 @@ fn check_decl(cx: &LateContext, decl: &Decl, bindings: &mut Vec<(Name, Span)>) {
     if in_external_macro(cx, decl.span) {
         return;
     }
-    if is_from_for_desugar(decl) {
+    if higher::is_from_for_desugar(decl) {
         return;
     }
     if let DeclLocal(ref local) = decl.node {

clippy_lints/src/types.rs

@@ -6,7 +6,7 @@ use rustc::ty;
 use std::cmp::Ordering;
 use syntax::ast::{IntTy, UintTy, FloatTy};
 use syntax::codemap::Span;
-use utils::{comparisons, in_external_macro, in_macro, is_from_for_desugar, match_def_path, snippet,
+use utils::{comparisons, higher, in_external_macro, in_macro, match_def_path, snippet,
             span_help_and_lint, span_lint};
 use utils::paths;
 
@@ -106,7 +106,7 @@ fn check_let_unit(cx: &LateContext, decl: &Decl) {
             if in_external_macro(cx, decl.span) || in_macro(cx, local.pat.span) {
                 return;
             }
-            if is_from_for_desugar(decl) {
+            if higher::is_from_for_desugar(decl) {
                 return;
             }
             span_lint(cx,

clippy_lints/src/utils/higher.rs

@@ -115,3 +115,36 @@ pub fn range(expr: &hir::Expr) -> Option<Range> {
     }
 }
 
+/// Checks if a `let` decl is from a `for` loop desugaring.
+pub fn is_from_for_desugar(decl: &hir::Decl) -> bool {
+    if_let_chain! {[
+        let hir::DeclLocal(ref loc) = decl.node,
+        let Some(ref expr) = loc.init,
+        let hir::ExprMatch(_, _, hir::MatchSource::ForLoopDesugar) = expr.node,
+    ], {
+        return true;
+    }}
+    false
+}
+
+/// Recover the essential nodes of a desugared for loop:
+/// `for pat in arg { body }` becomes `(pat, arg, body)`.
+pub fn for_loop(expr: &hir::Expr) -> Option<(&hir::Pat, &hir::Expr, &hir::Expr)> {
+    if_let_chain! {[
+        let hir::ExprMatch(ref iterexpr, ref arms, _) = expr.node,
+        let hir::ExprCall(_, ref iterargs) = iterexpr.node,
+        iterargs.len() == 1 && arms.len() == 1 && arms[0].guard.is_none(),
+        let hir::ExprLoop(ref block, _) = arms[0].body.node,
+        block.stmts.is_empty(),
+        let Some(ref loopexpr) = block.expr,
+        let hir::ExprMatch(_, ref innerarms, hir::MatchSource::ForLoopDesugar) = loopexpr.node,
+        innerarms.len() == 2 && innerarms[0].pats.len() == 1,
+        let hir::PatKind::TupleStruct(_, ref somepats, _) = innerarms[0].pats[0].node,
+        somepats.len() == 1
+    ], {
+        return Some((&somepats[0],
+                     &iterargs[0],
+                     &innerarms[0].body));
+    }}
+    None
+}

clippy_lints/src/utils/mod.rs

@@ -21,7 +21,6 @@ use syntax::ptr::P;
 pub mod cargo;
 pub mod comparisons;
 pub mod conf;
-pub mod higher;
 mod hir;
 pub mod paths;
 pub mod sugg;
@@ -82,6 +81,8 @@ macro_rules! if_let_chain {
     };
 }
 
+pub mod higher;
+
 /// Returns true if the two spans come from differing expansions (i.e. one is from a macro and one
 /// isn't).
 pub fn differing_macro_contexts(lhs: Span, rhs: Span) -> bool {
@@ -319,19 +320,6 @@ pub fn get_item_name(cx: &LateContext, expr: &Expr) -> Option<Name> {
     }
 }
 
-/// Checks if a `let` decl is from a `for` loop desugaring.
-pub fn is_from_for_desugar(decl: &Decl) -> bool {
-    if_let_chain! {[
-        let DeclLocal(ref loc) = decl.node,
-        let Some(ref expr) = loc.init,
-        let ExprMatch(_, _, MatchSource::ForLoopDesugar) = expr.node
-    ], {
-        return true;
-    }}
-    false
-}
-
-
 /// Convert a span to a code snippet if available, otherwise use default.
 ///
 /// # Example
@@ -706,25 +694,3 @@ pub fn same_tys<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, a: ty::Ty<'tcx>, b: ty::Ty
         infcx.can_equate(&new_a, &new_b).is_ok()
     })
 }
-
-/// Recover the essential nodes of a desugared for loop:
-/// `for pat in arg { body }` becomes `(pat, arg, body)`.
-pub fn recover_for_loop(expr: &Expr) -> Option<(&Pat, &Expr, &Expr)> {
-    if_let_chain! {[
-        let ExprMatch(ref iterexpr, ref arms, _) = expr.node,
-        let ExprCall(_, ref iterargs) = iterexpr.node,
-        iterargs.len() == 1 && arms.len() == 1 && arms[0].guard.is_none(),
-        let ExprLoop(ref block, _) = arms[0].body.node,
-        block.stmts.is_empty(),
-        let Some(ref loopexpr) = block.expr,
-        let ExprMatch(_, ref innerarms, MatchSource::ForLoopDesugar) = loopexpr.node,
-        innerarms.len() == 2 && innerarms[0].pats.len() == 1,
-        let PatKind::TupleStruct(_, ref somepats, _) = innerarms[0].pats[0].node,
-        somepats.len() == 1
-    ], {
-        return Some((&somepats[0],
-                     &iterargs[0],
-                     &innerarms[0].body));
-    }}
-    None
-}

clippy_lints/src/vec.rs

@@ -3,7 +3,7 @@ use rustc::ty::TypeVariants;
 use rustc::hir::*;
 use syntax::codemap::Span;
 use syntax::ptr::P;
-use utils::{is_expn_of, match_path, paths, recover_for_loop, snippet, span_lint_and_then};
+use utils::{higher, is_expn_of, match_path, paths, snippet, span_lint_and_then};
 
 /// **What it does:** This lint warns about using `&vec![..]` when using `&[..]` would be possible.
 ///
@@ -42,7 +42,7 @@ impl LateLintPass for Pass {
         }}
 
         // search for `for _ in vec![…]`
-        if let Some((_, arg, _)) = recover_for_loop(expr) {
+        if let Some((_, arg, _)) = higher::for_loop(expr) {
             // report the error around the `vec!` not inside `<std macros>:`
             let span = cx.sess().codemap().source_callsite(arg.span);
             check_vec_macro(cx, arg, span);