Move Arithmetic into Operators lint pass

Author: Jarcho

clippy_lints/src/lib.register_lints.rs

@@ -431,12 +431,12 @@ store.register_lints(&[
     non_octal_unix_permissions::NON_OCTAL_UNIX_PERMISSIONS,
     non_send_fields_in_send_ty::NON_SEND_FIELDS_IN_SEND_TY,
     nonstandard_macro_braces::NONSTANDARD_MACRO_BRACES,
-    numeric_arithmetic::FLOAT_ARITHMETIC,
-    numeric_arithmetic::INTEGER_ARITHMETIC,
     octal_escapes::OCTAL_ESCAPES,
     only_used_in_recursion::ONLY_USED_IN_RECURSION,
     open_options::NONSENSICAL_OPEN_OPTIONS,
     operators::ABSURD_EXTREME_COMPARISONS,
+    operators::FLOAT_ARITHMETIC,
+    operators::INTEGER_ARITHMETIC,
     option_env_unwrap::OPTION_ENV_UNWRAP,
     option_if_let_else::OPTION_IF_LET_ELSE,
     overflow_check_conditional::OVERFLOW_CHECK_CONDITIONAL,

clippy_lints/src/lib.register_restriction.rs

@@ -50,8 +50,8 @@ store.register_group(true, "clippy::restriction", Some("clippy_restriction"), ve
     LintId::of(module_style::MOD_MODULE_FILES),
     LintId::of(module_style::SELF_NAMED_MODULE_FILES),
     LintId::of(modulo_arithmetic::MODULO_ARITHMETIC),
-    LintId::of(numeric_arithmetic::FLOAT_ARITHMETIC),
-    LintId::of(numeric_arithmetic::INTEGER_ARITHMETIC),
+    LintId::of(operators::FLOAT_ARITHMETIC),
+    LintId::of(operators::INTEGER_ARITHMETIC),
     LintId::of(panic_in_result_fn::PANIC_IN_RESULT_FN),
     LintId::of(panic_unimplemented::PANIC),
     LintId::of(panic_unimplemented::TODO),

clippy_lints/src/lib.rs

@@ -331,7 +331,6 @@ mod non_expressive_names;
 mod non_octal_unix_permissions;
 mod non_send_fields_in_send_ty;
 mod nonstandard_macro_braces;
-mod numeric_arithmetic;
 mod octal_escapes;
 mod only_used_in_recursion;
 mod open_options;
@@ -705,7 +704,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(move || Box::new(doc::DocMarkdown::new(doc_valid_idents.clone())));
     store.register_late_pass(|| Box::new(neg_multiply::NegMultiply));
     store.register_late_pass(|| Box::new(mem_forget::MemForget));
-    store.register_late_pass(|| Box::new(numeric_arithmetic::NumericArithmetic::default()));
     store.register_late_pass(|| Box::new(assign_ops::AssignOps));
     store.register_late_pass(|| Box::new(let_if_seq::LetIfSeq));
     store.register_late_pass(|| Box::new(mixed_read_write_in_expression::EvalOrderDependence));
@@ -940,7 +938,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(|| Box::new(default_instead_of_iter_empty::DefaultIterEmpty));
     store.register_late_pass(move || Box::new(manual_rem_euclid::ManualRemEuclid::new(msrv)));
     store.register_late_pass(move || Box::new(manual_retain::ManualRetain::new(msrv)));
-    store.register_late_pass(|| Box::new(operators::Operators));
+    store.register_late_pass(|| Box::new(operators::Operators::default()));
     // add lints here, do not remove this comment, it's used in `new_lint`
 }
 

clippy_lints/src/numeric_arithmetic.rs

@@ -1,8 +1,9 @@
-use rustc_hir::{Expr, ExprKind};
+use rustc_hir::{Body, Expr, ExprKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 
 mod absurd_extreme_comparisons;
+mod numeric_arithmetic;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -36,16 +37,90 @@ declare_clippy_lint! {
     "a comparison with a maximum or minimum value that is always true or false"
 }
 
-pub struct Operators;
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for integer arithmetic operations which could overflow or panic.
+    ///
+    /// Specifically, checks for any operators (`+`, `-`, `*`, `<<`, etc) which are capable
+    /// of overflowing according to the [Rust
+    /// Reference](https://doc.rust-lang.org/reference/expressions/operator-expr.html#overflow),
+    /// or which can panic (`/`, `%`). No bounds analysis or sophisticated reasoning is
+    /// attempted.
+    ///
+    /// ### Why is this bad?
+    /// Integer overflow will trigger a panic in debug builds or will wrap in
+    /// release mode. Division by zero will cause a panic in either mode. In some applications one
+    /// wants explicitly checked, wrapping or saturating arithmetic.
+    ///
+    /// ### Example
+    /// ```rust
+    /// # let a = 0;
+    /// a + 1;
+    /// ```
+    #[clippy::version = "pre 1.29.0"]
+    pub INTEGER_ARITHMETIC,
+    restriction,
+    "any integer arithmetic expression which could overflow or panic"
+}
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for float arithmetic.
+    ///
+    /// ### Why is this bad?
+    /// For some embedded systems or kernel development, it
+    /// can be useful to rule out floating-point numbers.
+    ///
+    /// ### Example
+    /// ```rust
+    /// # let a = 0.0;
+    /// a + 1.0;
+    /// ```
+    #[clippy::version = "pre 1.29.0"]
+    pub FLOAT_ARITHMETIC,
+    restriction,
+    "any floating-point arithmetic statement"
+}
+
+#[derive(Default)]
+pub struct Operators {
+    arithmetic_context: numeric_arithmetic::Context,
+}
 impl_lint_pass!(Operators => [
     ABSURD_EXTREME_COMPARISONS,
+    INTEGER_ARITHMETIC,
+    FLOAT_ARITHMETIC,
 ]);
 impl<'tcx> LateLintPass<'tcx> for Operators {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
-        if let ExprKind::Binary(op, lhs, rhs) = e.kind {
-            if !e.span.from_expansion() {
-                absurd_extreme_comparisons::check(cx, e, op.node, lhs, rhs);
-            }
+        match e.kind {
+            ExprKind::Binary(op, lhs, rhs) => {
+                if !e.span.from_expansion() {
+                    absurd_extreme_comparisons::check(cx, e, op.node, lhs, rhs);
+                }
+                self.arithmetic_context.check_binary(cx, e, op.node, lhs, rhs);
+            },
+            ExprKind::AssignOp(op, lhs, rhs) => {
+                self.arithmetic_context.check_binary(cx, e, op.node, lhs, rhs);
+            },
+            ExprKind::Unary(op, arg) => {
+                if op == UnOp::Neg {
+                    self.arithmetic_context.check_negate(cx, e, arg);
+                }
+            },
+            _ => (),
         }
     }
+
+    fn check_expr_post(&mut self, _: &LateContext<'_>, e: &Expr<'_>) {
+        self.arithmetic_context.expr_post(e.hir_id);
+    }
+
+    fn check_body(&mut self, cx: &LateContext<'tcx>, b: &'tcx Body<'_>) {
+        self.arithmetic_context.enter_body(cx, b);
+    }
+
+    fn check_body_post(&mut self, cx: &LateContext<'tcx>, b: &'tcx Body<'_>) {
+        self.arithmetic_context.body_post(cx, b);
+    }
 }