X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=clippy_lints%2Fsrc%2Futils%2Fhigher.rs;h=63e9a27c5459d13c3684b97ff887214ea12e3731;hb=cc622608db7318b1c0fe3ccd541558436c7c6c4c;hp=682093b08e4c8c457e6f3b46c2ed3214565672d4;hpb=91ef4e3ae7b8cb71ac7e4f2940e87c23434101ec;p=rust.git

diff --git a/clippy_lints/src/utils/higher.rs b/clippy_lints/src/utils/higher.rs
index 682093b08e4..63e9a27c545 100644
--- a/clippy_lints/src/utils/higher.rs
+++ b/clippy_lints/src/utils/higher.rs
@@ -3,13 +3,14 @@
 
 #![deny(clippy::missing_docs_in_private_items)]
 
-use crate::utils::{is_expn_of, match_def_path, match_qpath, opt_def_id, paths, resolve_node};
+use crate::utils::{is_expn_of, match_def_path, match_qpath, paths};
 use if_chain::if_chain;
 use rustc::lint::LateContext;
 use rustc::{hir, ty};
 use syntax::ast;
 
-/// Convert a hir binary operator to the corresponding `ast` type.
+/// Converts a hir binary operator to the corresponding `ast` type.
+#[must_use]
 pub fn binop(op: hir::BinOpKind) -> ast::BinOpKind {
     match op {
         hir::BinOpKind::Eq => ast::BinOpKind::Eq,
@@ -46,15 +47,15 @@ pub struct Range<'a> {
 
 /// Higher a `hir` range to something similar to `ast::ExprKind::Range`.
 pub fn range<'a, 'b, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'b hir::Expr) -> Option<Range<'b>> {
-    /// Find the field named `name` in the field. Always return `Some` for
+    /// Finds the field named `name` in the field. Always return `Some` for
     /// convenience.
-    fn get_field<'a>(name: &str, fields: &'a [hir::Field]) -> Option<&'a hir::Expr> {
-        let expr = &fields.iter().find(|field| field.ident.name == name)?.expr;
+    fn get_field<'c>(name: &str, fields: &'c [hir::Field]) -> Option<&'c hir::Expr> {
+        let expr = &fields.iter().find(|field| field.ident.name.as_str() == name)?.expr;
 
         Some(expr)
     }
 
-    let def_path = match cx.tables.expr_ty(expr).sty {
+    let def_path = match cx.tables.expr_ty(expr).kind {
         ty::Adt(def, _) => cx.tcx.def_path(def.did),
         _ => return None,
     };
@@ -63,10 +64,10 @@ fn get_field<'a>(name: &str, fields: &'a [hir::Field]) -> Option<&'a hir::Expr>
     if def_path.data.len() != 3 {
         return None;
     }
-    if def_path.data.get(0)?.data.as_interned_str() != "ops" {
+    if def_path.data.get(0)?.data.as_interned_str().as_symbol() != sym!(ops) {
         return None;
     }
-    if def_path.data.get(1)?.data.as_interned_str() != "range" {
+    if def_path.data.get(1)?.data.as_interned_str().as_symbol() != sym!(range) {
         return None;
     }
     let type_name = def_path.data.get(2)?.data.as_interned_str();
@@ -86,7 +87,7 @@ fn get_field<'a>(name: &str, fields: &'a [hir::Field]) -> Option<&'a hir::Expr>
     // depending on
     // `#[no_std]`. Testing both instead of resolving the paths.
 
-    match expr.node {
+    match expr.kind {
         hir::ExprKind::Path(ref path) => {
             if match_qpath(path, &paths::RANGE_FULL_STD) || match_qpath(path, &paths::RANGE_FULL) {
                 Some(Range {
@@ -99,7 +100,7 @@ fn get_field<'a>(name: &str, fields: &'a [hir::Field]) -> Option<&'a hir::Expr>
             }
         },
         hir::ExprKind::Call(ref path, ref args) => {
-            if let hir::ExprKind::Path(ref path) = path.node {
+            if let hir::ExprKind::Path(ref path) = path.kind {
                 if match_qpath(path, &paths::RANGE_INCLUSIVE_STD_NEW) || match_qpath(path, &paths::RANGE_INCLUSIVE_NEW)
                 {
                     Some(Range {
@@ -148,8 +149,8 @@ fn get_field<'a>(name: &str, fields: &'a [hir::Field]) -> Option<&'a hir::Expr>
     }
 }
 
-/// Checks if a `let` decl is from a `for` loop desugaring.
-pub fn is_from_for_desugar(decl: &hir::Decl) -> bool {
+/// Checks if a `let` statement is from a `for` loop desugaring.
+pub fn is_from_for_desugar(local: &hir::Local) -> bool {
     // This will detect plain for-loops without an actual variable binding:
     //
     // ```
@@ -158,9 +159,8 @@ pub fn is_from_for_desugar(decl: &hir::Decl) -> bool {
     // }
     // ```
     if_chain! {
-        if let hir::DeclKind::Local(ref loc) = decl.node;
-        if let Some(ref expr) = loc.init;
-        if let hir::ExprKind::Match(_, _, hir::MatchSource::ForLoopDesugar) = expr.node;
+        if let Some(ref expr) = local.init;
+        if let hir::ExprKind::Match(_, _, hir::MatchSource::ForLoopDesugar) = expr.kind;
         then {
             return true;
         }
@@ -174,12 +174,8 @@ pub fn is_from_for_desugar(decl: &hir::Decl) -> bool {
     //     // anything
     // }
     // ```
-    if_chain! {
-        if let hir::DeclKind::Local(ref loc) = decl.node;
-        if let hir::LocalSource::ForLoopDesugar = loc.source;
-        then {
-            return true;
-        }
+    if let hir::LocalSource::ForLoopDesugar = local.source {
+        return true;
     }
 
     false
@@ -189,22 +185,59 @@ pub fn is_from_for_desugar(decl: &hir::Decl) -> bool {
 /// `for pat in arg { body }` becomes `(pat, arg, body)`.
 pub fn for_loop(expr: &hir::Expr) -> Option<(&hir::Pat, &hir::Expr, &hir::Expr)> {
     if_chain! {
-        if let hir::ExprKind::Match(ref iterexpr, ref arms, hir::MatchSource::ForLoopDesugar) = expr.node;
-        if let hir::ExprKind::Call(_, ref iterargs) = iterexpr.node;
+        if let hir::ExprKind::Match(ref iterexpr, ref arms, hir::MatchSource::ForLoopDesugar) = expr.kind;
+        if let hir::ExprKind::Call(_, ref iterargs) = iterexpr.kind;
         if iterargs.len() == 1 && arms.len() == 1 && arms[0].guard.is_none();
-        if let hir::ExprKind::Loop(ref block, _, _) = arms[0].body.node;
+        if let hir::ExprKind::Loop(ref block, _, _) = arms[0].body.kind;
         if block.expr.is_none();
         if let [ _, _, ref let_stmt, ref body ] = *block.stmts;
-        if let hir::StmtKind::Decl(ref decl, _) = let_stmt.node;
-        if let hir::DeclKind::Local(ref decl) = decl.node;
-        if let hir::StmtKind::Expr(ref expr, _) = body.node;
+        if let hir::StmtKind::Local(ref local) = let_stmt.kind;
+        if let hir::StmtKind::Expr(ref expr) = body.kind;
+        then {
+            return Some((&*local.pat, &iterargs[0], expr));
+        }
+    }
+    None
+}
+
+/// Recover the essential nodes of a desugared while loop:
+/// `while cond { body }` becomes `(cond, body)`.
+pub fn while_loop(expr: &hir::Expr) -> Option<(&hir::Expr, &hir::Expr)> {
+    if_chain! {
+        if let hir::ExprKind::Loop(block, _, hir::LoopSource::While) = &expr.kind;
+        if let hir::Block { expr: Some(expr), .. } = &**block;
+        if let hir::ExprKind::Match(cond, arms, hir::MatchSource::WhileDesugar) = &expr.kind;
+        if let hir::ExprKind::DropTemps(cond) = &cond.kind;
+        if let [arm, ..] = &arms[..];
+        if let hir::Arm { body, .. } = arm;
         then {
-            return Some((&*decl.pat, &iterargs[0], expr));
+            return Some((cond, body));
         }
     }
     None
 }
 
+/// Recover the essential nodes of a desugared if block
+/// `if cond { then } else { els }` becomes `(cond, then, Some(els))`
+pub fn if_block(expr: &hir::Expr) -> Option<(&hir::Expr, &hir::Expr, Option<&hir::Expr>)> {
+    if let hir::ExprKind::Match(ref cond, ref arms, hir::MatchSource::IfDesugar { contains_else_clause }) = expr.kind {
+        let cond = if let hir::ExprKind::DropTemps(ref cond) = cond.kind {
+            cond
+        } else {
+            panic!("If block desugar must contain DropTemps");
+        };
+        let then = &arms[0].body;
+        let els = if contains_else_clause {
+            Some(&*arms[1].body)
+        } else {
+            None
+        };
+        Some((cond, then, els))
+    } else {
+        None
+    }
+}
+
 /// Represent the pre-expansion arguments of a `vec!` invocation.
 pub enum VecArgs<'a> {
     /// `vec![elem; len]`
@@ -217,20 +250,20 @@ pub enum VecArgs<'a> {
 /// from `vec!`.
 pub fn vec_macro<'e>(cx: &LateContext<'_, '_>, expr: &'e hir::Expr) -> Option<VecArgs<'e>> {
     if_chain! {
-        if let hir::ExprKind::Call(ref fun, ref args) = expr.node;
-        if let hir::ExprKind::Path(ref path) = fun.node;
+        if let hir::ExprKind::Call(ref fun, ref args) = expr.kind;
+        if let hir::ExprKind::Path(ref qpath) = fun.kind;
         if is_expn_of(fun.span, "vec").is_some();
-        if let Some(fun_def_id) = opt_def_id(resolve_node(cx, path, fun.hir_id));
+        if let Some(fun_def_id) = cx.tables.qpath_res(qpath, fun.hir_id).opt_def_id();
         then {
-            return if match_def_path(cx.tcx, fun_def_id, &paths::VEC_FROM_ELEM) && args.len() == 2 {
+            return if match_def_path(cx, fun_def_id, &paths::VEC_FROM_ELEM) && args.len() == 2 {
                 // `vec![elem; size]` case
                 Some(VecArgs::Repeat(&args[0], &args[1]))
             }
-            else if match_def_path(cx.tcx, fun_def_id, &paths::SLICE_INTO_VEC) && args.len() == 1 {
+            else if match_def_path(cx, fun_def_id, &paths::SLICE_INTO_VEC) && args.len() == 1 {
                 // `vec![a, b, c]` case
                 if_chain! {
-                    if let hir::ExprKind::Box(ref boxed) = args[0].node;
-                    if let hir::ExprKind::Array(ref args) = boxed.node;
+                    if let hir::ExprKind::Box(ref boxed) = args[0].kind;
+                    if let hir::ExprKind::Array(ref args) = boxed.kind;
                     then {
                         return Some(VecArgs::Vec(&*args));
                     }