Exhaustively handle expressions in patterns

Author: oli-obk

clippy_lints/src/default_numeric_fallback.rs

@@ -3,8 +3,11 @@ use clippy_utils::numeric_literal;
 use clippy_utils::source::snippet_opt;
 use rustc_ast::ast::{LitFloatType, LitIntType, LitKind};
 use rustc_errors::Applicability;
-use rustc_hir::intravisit::{Visitor, walk_expr, walk_stmt};
-use rustc_hir::{Block, Body, ConstContext, Expr, ExprKind, FnRetTy, HirId, Lit, Stmt, StmtKind, StructTailExpr};
+use rustc_hir::intravisit::{Visitor, walk_expr, walk_pat, walk_stmt};
+use rustc_hir::{
+    Block, Body, ConstContext, Expr, ExprKind, FnRetTy, HirId, Lit, Pat, PatExpr, PatExprKind, PatKind, Stmt, StmtKind,
+    StructTailExpr,
+};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::{self, FloatTy, IntTy, PolyFnSig, Ty};
@@ -219,6 +222,22 @@ impl<'tcx> Visitor<'tcx> for NumericFallbackVisitor<'_, 'tcx> {
         walk_expr(self, expr);
     }
 
+    fn visit_pat(&mut self, pat: &'tcx Pat<'_>) {
+        match pat.kind {
+            PatKind::Lit(&PatExpr {
+                hir_id,
+                kind: PatExprKind::Lit { lit, .. },
+                ..
+            }) => {
+                let ty = self.cx.typeck_results().node_type(hir_id);
+                self.check_lit(lit, ty, hir_id);
+                return;
+            },
+            _ => {},
+        }
+        walk_pat(self, pat)
+    }
+
     fn visit_stmt(&mut self, stmt: &'tcx Stmt<'_>) {
         match stmt.kind {
             // we cannot check the exact type since it's a hir::Ty which does not implement `is_numeric`

clippy_lints/src/len_zero.rs

@@ -8,8 +8,8 @@ use rustc_hir::def::Res;
 use rustc_hir::def_id::{DefId, DefIdSet};
 use rustc_hir::{
     AssocItemKind, BinOpKind, Expr, ExprKind, FnRetTy, GenericArg, GenericBound, ImplItem, ImplItemKind,
-    ImplicitSelfKind, Item, ItemKind, Mutability, Node, OpaqueTyOrigin, PatKind, PathSegment, PrimTy, QPath,
-    TraitItemRef, TyKind,
+    ImplicitSelfKind, Item, ItemKind, Mutability, Node, OpaqueTyOrigin, PatExprKind, PatKind, PathSegment, PrimTy,
+    QPath, TraitItemRef, TyKind,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{self, AssocKind, FnSig, Ty};
@@ -163,7 +163,13 @@ impl<'tcx> LateLintPass<'tcx> for LenZero {
         if let ExprKind::Let(lt) = expr.kind
             && match lt.pat.kind {
                 PatKind::Slice([], None, []) => true,
-                PatKind::Lit(lit) if is_empty_string(lit) => true,
+                PatKind::Lit(lit) => match lit.kind {
+                    PatExprKind::Lit { lit, .. } => match lit.node {
+                        LitKind::Str(lit, _) => lit.as_str().is_empty(),
+                        _ => false,
+                    },
+                    _ => false,
+                },
                 _ => false,
             }
             && !expr.span.from_expansion()

clippy_lints/src/manual_is_ascii_check.rs

@@ -7,7 +7,7 @@ use clippy_utils::{higher, is_in_const_context, path_to_local, peel_ref_operator
 use rustc_ast::LitKind::{Byte, Char};
 use rustc_ast::ast::RangeLimits;
 use rustc_errors::Applicability;
-use rustc_hir::{Expr, ExprKind, Node, Param, PatKind, RangeEnd};
+use rustc_hir::{Expr, ExprKind, Node, Param, PatKind, RangeEnd, PatExpr, PatExprKind, Lit};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
 use rustc_session::impl_lint_pass;
@@ -115,7 +115,7 @@ impl<'tcx> LateLintPass<'tcx> for ManualIsAsciiCheck {
         {
             let arg = peel_ref_operators(cx, arg);
             let ty_sugg = get_ty_sugg(cx, arg, start);
-            let range = check_range(start, end);
+            let range = check_expr_range(start, end);
             check_is_ascii(cx, expr.span, arg, &range, ty_sugg);
         }
     }
@@ -196,19 +196,34 @@ fn check_pat(pat_kind: &PatKind<'_>) -> CharRange {
     }
 }
 
-fn check_range(start: &Expr<'_>, end: &Expr<'_>) -> CharRange {
+fn check_expr_range(start: &Expr<'_>, end: &Expr<'_>) -> CharRange {
     if let ExprKind::Lit(start_lit) = &start.kind
         && let ExprKind::Lit(end_lit) = &end.kind
     {
-        match (&start_lit.node, &end_lit.node) {
-            (Char('a'), Char('z')) | (Byte(b'a'), Byte(b'z')) => CharRange::LowerChar,
-            (Char('A'), Char('Z')) | (Byte(b'A'), Byte(b'Z')) => CharRange::UpperChar,
-            (Char('a'), Char('f')) | (Byte(b'a'), Byte(b'f')) => CharRange::LowerHexLetter,
-            (Char('A'), Char('F')) | (Byte(b'A'), Byte(b'F')) => CharRange::UpperHexLetter,
-            (Char('0'), Char('9')) | (Byte(b'0'), Byte(b'9')) => CharRange::Digit,
-            _ => CharRange::Otherwise,
-        }
+        check_lit_range(start_lit, end_lit)
+    } else {
+        CharRange::Otherwise
+    }
+}
+
+
+fn check_range(start: &PatExpr<'_>, end: &PatExpr<'_>) -> CharRange {
+    if let PatExprKind::Lit{ lit: start_lit, negated: false } = &start.kind
+        && let PatExprKind::Lit{ lit: end_lit, negated: false  } = &end.kind
+    {
+        check_lit_range(start_lit, end_lit)
     } else {
         CharRange::Otherwise
     }
 }
+
+fn check_lit_range(start_lit: &Lit, end_lit: &Lit) -> CharRange {
+    match (&start_lit.node, &end_lit.node) {
+        (Char('a'), Char('z')) | (Byte(b'a'), Byte(b'z')) => CharRange::LowerChar,
+        (Char('A'), Char('Z')) | (Byte(b'A'), Byte(b'Z')) => CharRange::UpperChar,
+        (Char('a'), Char('f')) | (Byte(b'a'), Byte(b'f')) => CharRange::LowerHexLetter,
+        (Char('A'), Char('F')) | (Byte(b'A'), Byte(b'F')) => CharRange::UpperHexLetter,
+        (Char('0'), Char('9')) | (Byte(b'0'), Byte(b'9')) => CharRange::Digit,
+        _ => CharRange::Otherwise,
+    }
+}

clippy_lints/src/manual_range_patterns.rs

@@ -3,7 +3,7 @@ use clippy_utils::source::SpanRangeExt;
 use rustc_ast::LitKind;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::Applicability;
-use rustc_hir::{Expr, ExprKind, PatKind, RangeEnd, UnOp};
+use rustc_hir::{PatExpr, PatExprKind, PatKind, RangeEnd};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::declare_lint_pass;
@@ -38,14 +38,13 @@ declare_clippy_lint! {
 }
 declare_lint_pass!(ManualRangePatterns => [MANUAL_RANGE_PATTERNS]);
 
-fn expr_as_i128(expr: &Expr<'_>) -> Option<i128> {
-    if let ExprKind::Unary(UnOp::Neg, expr) = expr.kind {
-        expr_as_i128(expr).map(|num| -num)
-    } else if let ExprKind::Lit(lit) = expr.kind
+fn expr_as_i128(expr: &PatExpr<'_>) -> Option<i128> {
+    if let PatExprKind::Lit { lit, negated } = expr.kind
         && let LitKind::Int(num, _) = lit.node
     {
         // Intentionally not handling numbers greater than i128::MAX (for u128 literals) for now.
-        num.get().try_into().ok()
+        let n = i128::try_from(num.get()).ok()?;
+        Some(if negated { -n } else { n })
     } else {
         None
     }
@@ -58,7 +57,7 @@ struct Num {
 }
 
 impl Num {
-    fn new(expr: &Expr<'_>) -> Option<Self> {
+    fn new(expr: &PatExpr<'_>) -> Option<Self> {
         Some(Self {
             val: expr_as_i128(expr)?,
             span: expr.span,

clippy_lints/src/matches/match_bool.rs

@@ -4,7 +4,7 @@ use clippy_utils::source::{expr_block, snippet};
 use clippy_utils::sugg::Sugg;
 use rustc_ast::LitKind;
 use rustc_errors::Applicability;
-use rustc_hir::{Arm, Expr, ExprKind, PatKind};
+use rustc_hir::{Arm, Expr, PatExprKind, PatKind};
 use rustc_lint::LateContext;
 use rustc_middle::ty;
 
@@ -22,7 +22,7 @@ pub(crate) fn check(cx: &LateContext<'_>, scrutinee: &Expr<'_>, arms: &[Arm<'_>]
                 if arms.len() == 2 {
                     // no guards
                     let exprs = if let PatKind::Lit(arm_bool) = arms[0].pat.kind {
-                        if let ExprKind::Lit(lit) = arm_bool.kind {
+                        if let PatExprKind::Lit { lit, .. } = arm_bool.kind {
                             match lit.node {
                                 LitKind::Bool(true) => Some((arms[0].body, arms[1].body)),
                                 LitKind::Bool(false) => Some((arms[1].body, arms[0].body)),

clippy_lints/src/matches/match_same_arms.rs

@@ -7,7 +7,7 @@ use rustc_arena::DroplessArena;
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::def_id::DefId;
-use rustc_hir::{Arm, Expr, ExprKind, HirId, HirIdMap, HirIdMapEntry, HirIdSet, Pat, PatKind, RangeEnd};
+use rustc_hir::{Arm, Expr, PatExprKind, HirId, HirIdMap, HirIdMapEntry, HirIdSet, Pat, PatKind, RangeEnd};
 use rustc_lint::builtin::NON_EXHAUSTIVE_OMITTED_PATTERNS;
 use rustc_lint::{LateContext, LintContext};
 use rustc_middle::ty;
@@ -313,7 +313,7 @@ impl<'a> NormalizedPat<'a> {
             },
             PatKind::Lit(e) => match &e.kind {
                 // TODO: Handle negative integers. They're currently treated as a wild match.
-                ExprKind::Lit(lit) => match lit.node {
+                PatExprKind::Lit{ lit, negated: false } => match lit.node {
                     LitKind::Str(sym, _) => Self::LitStr(sym),
                     LitKind::ByteStr(ref bytes, _) | LitKind::CStr(ref bytes, _) => Self::LitBytes(bytes),
                     LitKind::Byte(val) => Self::LitInt(val.into()),
@@ -330,7 +330,7 @@ impl<'a> NormalizedPat<'a> {
                 let start = match start {
                     None => 0,
                     Some(e) => match &e.kind {
-                        ExprKind::Lit(lit) => match lit.node {
+                        PatExprKind::Lit { lit, negated: false } => match lit.node {
                             LitKind::Int(val, _) => val.get(),
                             LitKind::Char(val) => val.into(),
                             LitKind::Byte(val) => val.into(),
@@ -342,7 +342,7 @@ impl<'a> NormalizedPat<'a> {
                 let (end, bounds) = match end {
                     None => (u128::MAX, RangeEnd::Included),
                     Some(e) => match &e.kind {
-                        ExprKind::Lit(lit) => match lit.node {
+                        PatExprKind::Lit { lit, negated: false } => match lit.node {
                             LitKind::Int(val, _) => (val.get(), bounds),
                             LitKind::Char(val) => (val.into(), bounds),
                             LitKind::Byte(val) => (val.into(), bounds),

clippy_lints/src/matches/match_str_case_mismatch.rs

@@ -5,7 +5,7 @@ use clippy_utils::ty::is_type_lang_item;
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::{Visitor, walk_expr};
-use rustc_hir::{Arm, Expr, ExprKind, LangItem, PatKind};
+use rustc_hir::{Arm, Expr, ExprKind, PatExpr, PatExprKind, LangItem, PatKind};
 use rustc_lint::LateContext;
 use rustc_middle::ty;
 use rustc_span::Span;
@@ -85,8 +85,8 @@ fn verify_case<'a>(case_method: &'a CaseMethod, arms: &'a [Arm<'_>]) -> Option<(
     };
 
     for arm in arms {
-        if let PatKind::Lit(Expr {
-            kind: ExprKind::Lit(lit),
+        if let PatKind::Lit(PatExpr {
+            kind: PatExprKind::Lit { lit, negated: false },
             ..
         }) = arm.pat.kind
             && let LitKind::Str(symbol, _) = lit.node

clippy_lints/src/matches/needless_match.rs

@@ -8,7 +8,7 @@ use clippy_utils::{
 };
 use rustc_errors::Applicability;
 use rustc_hir::LangItem::OptionNone;
-use rustc_hir::{Arm, BindingMode, ByRef, Expr, ExprKind, ItemKind, Node, Pat, PatKind, Path, QPath};
+use rustc_hir::{Arm, BindingMode, ByRef, Expr, ExprKind, ItemKind, Node, Pat, PatExprKind, PatKind, Path, QPath};
 use rustc_lint::LateContext;
 use rustc_span::sym;
 
@@ -133,7 +133,7 @@ fn expr_ty_matches_p_ty(cx: &LateContext<'_>, expr: &Expr<'_>, p_expr: &Expr<'_>
         },
         // compare match_expr ty with RetTy in `fn foo() -> RetTy`
         Node::Item(item) => {
-            if let ItemKind::Fn{ .. } = item.kind {
+            if let ItemKind::Fn { .. } = item.kind {
                 let output = cx
                     .tcx
                     .fn_sig(item.owner_id)
@@ -189,8 +189,12 @@ fn pat_same_as_expr(pat: &Pat<'_>, expr: &Expr<'_>) -> bool {
             });
         },
         // Example: `5 => 5`
-        (PatKind::Lit(pat_lit_expr), ExprKind::Lit(expr_spanned)) => {
-            if let ExprKind::Lit(pat_spanned) = &pat_lit_expr.kind {
+        (PatKind::Lit(pat_expr_expr), ExprKind::Lit(expr_spanned)) => {
+            if let PatExprKind::Lit {
+                lit: pat_spanned,
+                negated: false,
+            } = &pat_expr_expr.kind
+            {
                 return pat_spanned.node == expr_spanned.node;
             }
         },

clippy_lints/src/matches/overlapping_arms.rs

@@ -34,13 +34,13 @@ fn all_ranges<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'_>], ty: Ty<'tcx>)
             if let Arm { pat, guard: None, .. } = *arm {
                 if let PatKind::Range(ref lhs, ref rhs, range_end) = pat.kind {
                     let lhs_const = if let Some(lhs) = lhs {
-                        ConstEvalCtxt::new(cx).eval(lhs)?
+                        ConstEvalCtxt::new(cx).eval_pat_expr(lhs)?
                     } else {
                         let min_val_const = ty.numeric_min_val(cx.tcx)?;
                         mir_to_const(cx.tcx, mir::Const::from_ty_const(min_val_const, ty, cx.tcx))?
                     };
                     let rhs_const = if let Some(rhs) = rhs {
-                        ConstEvalCtxt::new(cx).eval(rhs)?
+                        ConstEvalCtxt::new(cx).eval_pat_expr(rhs)?
                     } else {
                         let max_val_const = ty.numeric_max_val(cx.tcx)?;
                         mir_to_const(cx.tcx, mir::Const::from_ty_const(max_val_const, ty, cx.tcx))?
@@ -58,7 +58,9 @@ fn all_ranges<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'_>], ty: Ty<'tcx>)
                 }
 
                 if let PatKind::Lit(value) = pat.kind {
-                    let value = ConstEvalCtxt::new(cx).eval_full_int(value)?;
+                    let value = ConstEvalCtxt::new(cx)
+                        .eval_pat_expr(value)?
+                        .int_value(cx.tcx, cx.typeck_results().node_type(pat.hir_id))?;
                     return Some(SpannedRange {
                         span: pat.span,
                         node: (value, EndBound::Included(value)),

clippy_lints/src/matches/redundant_pattern_match.rs

@@ -9,7 +9,7 @@ use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::LangItem::{self, OptionNone, OptionSome, PollPending, PollReady, ResultErr, ResultOk};
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::{Arm, Expr, ExprKind, Node, Pat, PatKind, QPath, UnOp};
+use rustc_hir::{Arm, Expr, ExprKind, Node, Pat, PatKind, QPath, UnOp, PatExprKind};
 use rustc_lint::LateContext;
 use rustc_middle::ty::{self, GenericArgKind, Ty};
 use rustc_span::{Span, Symbol, sym};
@@ -75,7 +75,7 @@ fn find_match_true<'tcx>(
     message: &'static str,
 ) {
     if let PatKind::Lit(lit) = pat.kind
-        && let ExprKind::Lit(lit) = lit.kind
+        && let PatExprKind::Lit{ lit, negated: false } = lit.kind
         && let LitKind::Bool(pat_is_true) = lit.node
     {
         let mut applicability = Applicability::MachineApplicable;