Add semicolon-outside/inside-block lints

CHANGELOG.md

@@ -4353,6 +4353,8 @@ Released 2018-09-13
 [`self_named_constructors`]: https://rust-lang.github.io/rust-clippy/master/index.html#self_named_constructors
 [`self_named_module_files`]: https://rust-lang.github.io/rust-clippy/master/index.html#self_named_module_files
 [`semicolon_if_nothing_returned`]: https://rust-lang.github.io/rust-clippy/master/index.html#semicolon_if_nothing_returned
+[`semicolon_inside_block`]: https://rust-lang.github.io/rust-clippy/master/index.html#semicolon_inside_block
+[`semicolon_outside_block`]: https://rust-lang.github.io/rust-clippy/master/index.html#semicolon_outside_block
 [`separated_literal_suffix`]: https://rust-lang.github.io/rust-clippy/master/index.html#separated_literal_suffix
 [`serde_api_misuse`]: https://rust-lang.github.io/rust-clippy/master/index.html#serde_api_misuse
 [`shadow_reuse`]: https://rust-lang.github.io/rust-clippy/master/index.html#shadow_reuse

clippy_lints/src/declared_lints.rs

@@ -525,6 +525,8 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::returns::NEEDLESS_RETURN_INFO,
     crate::same_name_method::SAME_NAME_METHOD_INFO,
     crate::self_named_constructors::SELF_NAMED_CONSTRUCTORS_INFO,
+    crate::semicolon_block::SEMICOLON_INSIDE_BLOCK_INFO,
+    crate::semicolon_block::SEMICOLON_OUTSIDE_BLOCK_INFO,
     crate::semicolon_if_nothing_returned::SEMICOLON_IF_NOTHING_RETURNED_INFO,
     crate::serde_api::SERDE_API_MISUSE_INFO,
     crate::shadow::SHADOW_REUSE_INFO,

clippy_lints/src/lib.rs

@@ -257,6 +257,7 @@ mod return_self_not_must_use;
 mod returns;
 mod same_name_method;
 mod self_named_constructors;
+mod semicolon_block;
 mod semicolon_if_nothing_returned;
 mod serde_api;
 mod shadow;
@@ -884,6 +885,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(|_| Box::new(from_raw_with_void_ptr::FromRawWithVoidPtr));
     store.register_late_pass(|_| Box::new(suspicious_xor_used_as_pow::ConfusingXorAndPow));
     store.register_late_pass(move |_| Box::new(manual_is_ascii_check::ManualIsAsciiCheck::new(msrv())));
+    store.register_late_pass(|_| Box::new(semicolon_block::SemicolonBlock));
     // add lints here, do not remove this comment, it's used in `new_lint`
 }
 

clippy_lints/src/semicolon_block.rs

@@ -0,0 +1,131 @@
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet_with_macro_callsite;
+use clippy_utils::{get_parent_expr_for_hir, get_parent_node};
+use rustc_errors::Applicability;
+use rustc_hir::{Block, Expr, ExprKind, Node, Stmt, StmtKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+    /// ### What it does
+    ///
+    /// For () returning expressions, check that the semicolon is inside the block.
+    ///
+    /// ### Why is this bad?
+    ///
+    /// For consistency it's best to have the semicolon inside/outside the block. Either way is fine and this lint suggests inside the block.
+    /// Take a look at `semicolon_outside_block` for the other alternative.
+    ///
+    /// ### Example
+    ///
+    /// ```rust
+    /// # fn f(_: u32) {}
+    /// # let x = 0;
+    /// unsafe { f(x) };
+    /// ```
+    /// Use instead:
+    /// ```rust
+    /// # fn f(_: u32) {}
+    /// # let x = 0;
+    /// unsafe { f(x); }
+    /// ```
+    #[clippy::version = "1.66.0"]
+    pub SEMICOLON_INSIDE_BLOCK,
+    restriction,
+    "add a semicolon inside the block"
+}
+declare_clippy_lint! {
+    /// ### What it does
+    ///
+    /// For () returning expressions, check that the semicolon is outside the block.
+    ///
+    /// ### Why is this bad?
+    ///
+    /// For consistency it's best to have the semicolon inside/outside the block. Either way is fine and this lint suggests outside the block.
+    /// Take a look at `semicolon_inside_block` for the other alternative.
+    ///
+    /// ### Example
+    ///
+    /// ```rust
+    /// # fn f(_: u32) {}
+    /// # let x = 0;
+    /// unsafe { f(x); }
+    /// ```
+    /// Use instead:
+    /// ```rust
+    /// # fn f(_: u32) {}
+    /// # let x = 0;
+    /// unsafe { f(x) };
+    /// ```
+    #[clippy::version = "1.66.0"]
+    pub SEMICOLON_OUTSIDE_BLOCK,
+    restriction,
+    "add a semicolon outside the block"
+}
+declare_lint_pass!(SemicolonBlock => [SEMICOLON_INSIDE_BLOCK, SEMICOLON_OUTSIDE_BLOCK]);
+
+impl LateLintPass<'_> for SemicolonBlock {
+    fn check_block(&mut self, cx: &LateContext<'_>, block: &Block<'_>) {
+        semicolon_inside_block(cx, block);
+        semicolon_outside_block(cx, block);
+    }
+}
+
+fn semicolon_inside_block(cx: &LateContext<'_>, block: &Block<'_>) {
+    if !block.span.from_expansion()
+    && let Some(tail) = block.expr
+    && let Some(block_expr @ Expr { kind: ExprKind::Block(_, _), ..}) = get_parent_expr_for_hir(cx, block.hir_id)
+    && let Some(Node::Stmt(Stmt { kind: StmtKind::Semi(_), span, .. })) = get_parent_node(cx.tcx, block_expr.hir_id)
+    {
+        let expr_snip = snippet_with_macro_callsite(cx, tail.span, "..");
+
+        let mut suggestion: String = snippet_with_macro_callsite(cx, block.span, "..").to_string();
+
+        if let Some((expr_offset, _)) = suggestion.rmatch_indices(&*expr_snip).next() {
+            suggestion.insert(expr_offset + expr_snip.len(), ';');
+        } else {
+            return;
+        }
+
+        span_lint_and_sugg(
+            cx,
+            SEMICOLON_INSIDE_BLOCK,
+            *span,
+            "consider moving the `;` inside the block for consistent formatting",
+            "put the `;` here",
+            suggestion,
+            Applicability::MaybeIncorrect,
+        );
+    }
+}
+
+fn semicolon_outside_block(cx: &LateContext<'_>, block: &Block<'_>) {
+    if !block.span.from_expansion()
+    && block.expr.is_none()
+    && let [.., Stmt { kind: StmtKind::Semi(expr), .. }] = block.stmts
+    && let Some(block_expr @ Expr { kind: ExprKind::Block(_, _), ..}) = get_parent_expr_for_hir(cx,block.hir_id)
+    && let Some(Node::Stmt(Stmt { kind: StmtKind::Expr(_), .. })) = get_parent_node(cx.tcx, block_expr.hir_id) {
+        let expr_snip = snippet_with_macro_callsite(cx, expr.span, "..");
+
+        let mut suggestion: String = snippet_with_macro_callsite(cx, block.span, "..").to_string();
+
+        if let Some((expr_offset, _)) = suggestion.rmatch_indices(&*expr_snip).next()
+        && let Some(semi_offset) = suggestion[expr_offset + expr_snip.len()..].find(';') {
+            suggestion.remove(expr_offset +  expr_snip.len() + semi_offset);
+        } else {
+            return;
+        }
+
+        suggestion.push(';');
+
+        span_lint_and_sugg(
+            cx,
+            SEMICOLON_OUTSIDE_BLOCK,
+            block.span,
+            "consider moving the `;` outside the block for consistent formatting",
+            "put the `;` outside the block",
+            suggestion,
+            Applicability::MaybeIncorrect,
+        );
+    }
+}

tests/ui/semicolon_inside_block.fixed

@@ -0,0 +1,83 @@
+// run-rustfix
+#![allow(
+    unused,
+    clippy::unused_unit,
+    clippy::unnecessary_operation,
+    clippy::no_effect,
+    clippy::single_element_loop
+)]
+#![warn(clippy::semicolon_inside_block)]
+
+macro_rules! m {
+    (()) => {
+        ()
+    };
+    (0) => {{
+        0
+    };};
+    (1) => {{
+        1;
+    }};
+    (2) => {{
+        2;
+    }};
+}
+
+fn unit_fn_block() {
+    ()
+}
+
+#[rustfmt::skip]
+fn main() {
+    { unit_fn_block() }
+    unsafe { unit_fn_block() }
+
+    {
+        unit_fn_block()
+    }
+
+    { unit_fn_block(); }
+    unsafe { unit_fn_block(); }
+
+    { unit_fn_block(); }
+    unsafe { unit_fn_block(); }
+
+    { unit_fn_block(); };
+    unsafe { unit_fn_block(); };
+
+    {
+        unit_fn_block();
+        unit_fn_block();
+    }
+    {
+        unit_fn_block();
+        unit_fn_block();
+    }
+    {
+        unit_fn_block();
+        unit_fn_block();
+    };
+
+    { m!(()); }
+    { m!(()); }
+    { m!(()); };
+    m!(0);
+    m!(1);
+    m!(2);
+
+    for _ in [()] {
+        unit_fn_block();
+    }
+    for _ in [()] {
+        unit_fn_block()
+    }
+
+    let _d = || {
+        unit_fn_block();
+    };
+    let _d = || {
+        unit_fn_block()
+    };
+
+    unit_fn_block()
+}

tests/ui/semicolon_inside_block.rs

@@ -0,0 +1,83 @@
+// run-rustfix
+#![allow(
+    unused,
+    clippy::unused_unit,
+    clippy::unnecessary_operation,
+    clippy::no_effect,
+    clippy::single_element_loop
+)]
+#![warn(clippy::semicolon_inside_block)]
+
+macro_rules! m {
+    (()) => {
+        ()
+    };
+    (0) => {{
+        0
+    };};
+    (1) => {{
+        1;
+    }};
+    (2) => {{
+        2;
+    }};
+}
+
+fn unit_fn_block() {
+    ()
+}
+
+#[rustfmt::skip]
+fn main() {
+    { unit_fn_block() }
+    unsafe { unit_fn_block() }
+
+    {
+        unit_fn_block()
+    }
+
+    { unit_fn_block() };
+    unsafe { unit_fn_block() };
+
+    { unit_fn_block(); }
+    unsafe { unit_fn_block(); }
+
+    { unit_fn_block(); };
+    unsafe { unit_fn_block(); };
+
+    {
+        unit_fn_block();
+        unit_fn_block()
+    };
+    {
+        unit_fn_block();
+        unit_fn_block();
+    }
+    {
+        unit_fn_block();
+        unit_fn_block();
+    };
+
+    { m!(()) };
+    { m!(()); }
+    { m!(()); };
+    m!(0);
+    m!(1);
+    m!(2);
+
+    for _ in [()] {
+        unit_fn_block();
+    }
+    for _ in [()] {
+        unit_fn_block()
+    }
+
+    let _d = || {
+        unit_fn_block();
+    };
+    let _d = || {
+        unit_fn_block()
+    };
+
+    unit_fn_block()
+}

tests/ui/semicolon_inside_block.stderr

@@ -0,0 +1,39 @@
+error: consider moving the `;` inside the block for consistent formatting
+  --> $DIR/semicolon_inside_block.rs:39:5
+   |
+LL |     { unit_fn_block() };
+   |     ^^^^^^^^^^^^^^^^^^^^ help: put the `;` here: `{ unit_fn_block(); }`
+   |
+   = note: `-D clippy::semicolon-inside-block` implied by `-D warnings`
+
+error: consider moving the `;` inside the block for consistent formatting
+  --> $DIR/semicolon_inside_block.rs:40:5
+   |
+LL |     unsafe { unit_fn_block() };
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: put the `;` here: `unsafe { unit_fn_block(); }`
+
+error: consider moving the `;` inside the block for consistent formatting
+  --> $DIR/semicolon_inside_block.rs:48:5
+   |
+LL | /     {
+LL | |         unit_fn_block();
+LL | |         unit_fn_block()
+LL | |     };
+   | |______^
+   |
+help: put the `;` here
+   |
+LL ~     {
+LL +         unit_fn_block();
+LL +         unit_fn_block();
+LL +     }
+   |
+
+error: consider moving the `;` inside the block for consistent formatting
+  --> $DIR/semicolon_inside_block.rs:61:5
+   |
+LL |     { m!(()) };
+   |     ^^^^^^^^^^^ help: put the `;` here: `{ m!(()); }`
+
+error: aborting due to 4 previous errors
+

tests/ui/semicolon_outside_block.fixed

@@ -0,0 +1,83 @@
+// run-rustfix
+#![allow(
+    unused,
+    clippy::unused_unit,
+    clippy::unnecessary_operation,
+    clippy::no_effect,
+    clippy::single_element_loop
+)]
+#![warn(clippy::semicolon_outside_block)]
+
+macro_rules! m {
+    (()) => {
+        ()
+    };
+    (0) => {{
+        0
+    };};
+    (1) => {{
+        1;
+    }};
+    (2) => {{
+        2;
+    }};
+}
+
+fn unit_fn_block() {
+    ()
+}
+
+#[rustfmt::skip]
+fn main() {
+    { unit_fn_block() }
+    unsafe { unit_fn_block() }
+
+    {
+        unit_fn_block()
+    }
+
+    { unit_fn_block() };
+    unsafe { unit_fn_block() };
+
+    { unit_fn_block() };
+    unsafe { unit_fn_block() };
+
+    { unit_fn_block(); };
+    unsafe { unit_fn_block(); };
+
+    {
+        unit_fn_block();
+        unit_fn_block()
+    };
+    {
+        unit_fn_block();
+        unit_fn_block()
+    };
+    {
+        unit_fn_block();
+        unit_fn_block();
+    };
+
+    { m!(()) };
+    { m!(()) };
+    { m!(()); };
+    m!(0);
+    m!(1);
+    m!(2);
+
+    for _ in [()] {
+        unit_fn_block();
+    }
+    for _ in [()] {
+        unit_fn_block()
+    }
+
+    let _d = || {
+        unit_fn_block();
+    };
+    let _d = || {
+        unit_fn_block()
+    };
+
+    unit_fn_block()
+}

tests/ui/semicolon_outside_block.rs

@@ -0,0 +1,83 @@
+// run-rustfix
+#![allow(
+    unused,
+    clippy::unused_unit,
+    clippy::unnecessary_operation,
+    clippy::no_effect,
+    clippy::single_element_loop
+)]
+#![warn(clippy::semicolon_outside_block)]
+
+macro_rules! m {
+    (()) => {
+        ()
+    };
+    (0) => {{
+        0
+    };};
+    (1) => {{
+        1;
+    }};
+    (2) => {{
+        2;
+    }};
+}
+
+fn unit_fn_block() {
+    ()
+}
+
+#[rustfmt::skip]
+fn main() {
+    { unit_fn_block() }
+    unsafe { unit_fn_block() }
+
+    {
+        unit_fn_block()
+    }
+
+    { unit_fn_block() };
+    unsafe { unit_fn_block() };
+
+    { unit_fn_block(); }
+    unsafe { unit_fn_block(); }
+
+    { unit_fn_block(); };
+    unsafe { unit_fn_block(); };
+
+    {
+        unit_fn_block();
+        unit_fn_block()
+    };
+    {
+        unit_fn_block();
+        unit_fn_block();
+    }
+    {
+        unit_fn_block();
+        unit_fn_block();
+    };
+
+    { m!(()) };
+    { m!(()); }
+    { m!(()); };
+    m!(0);
+    m!(1);
+    m!(2);
+
+    for _ in [()] {
+        unit_fn_block();
+    }
+    for _ in [()] {
+        unit_fn_block()
+    }
+
+    let _d = || {
+        unit_fn_block();
+    };
+    let _d = || {
+        unit_fn_block()
+    };
+
+    unit_fn_block()
+}

tests/ui/semicolon_outside_block.stderr

@@ -0,0 +1,39 @@
+error: consider moving the `;` outside the block for consistent formatting
+  --> $DIR/semicolon_outside_block.rs:42:5
+   |
+LL |     { unit_fn_block(); }
+   |     ^^^^^^^^^^^^^^^^^^^^ help: put the `;` outside the block: `{ unit_fn_block() };`
+   |
+   = note: `-D clippy::semicolon-outside-block` implied by `-D warnings`
+
+error: consider moving the `;` outside the block for consistent formatting
+  --> $DIR/semicolon_outside_block.rs:43:5
+   |
+LL |     unsafe { unit_fn_block(); }
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: put the `;` outside the block: `unsafe { unit_fn_block() };`
+
+error: consider moving the `;` outside the block for consistent formatting
+  --> $DIR/semicolon_outside_block.rs:52:5
+   |
+LL | /     {
+LL | |         unit_fn_block();
+LL | |         unit_fn_block();
+LL | |     }
+   | |_____^
+   |
+help: put the `;` outside the block
+   |
+LL ~     {
+LL +         unit_fn_block();
+LL +         unit_fn_block()
+LL +     };
+   |
+
+error: consider moving the `;` outside the block for consistent formatting
+  --> $DIR/semicolon_outside_block.rs:62:5
+   |
+LL |     { m!(()); }
+   |     ^^^^^^^^^^^ help: put the `;` outside the block: `{ m!(()) };`
+
+error: aborting due to 4 previous errors
+