diff options
Diffstat (limited to 'src/tools/clippy/clippy_lints/src/semicolon_block.rs')
-rw-r--r-- | src/tools/clippy/clippy_lints/src/semicolon_block.rs | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/src/tools/clippy/clippy_lints/src/semicolon_block.rs b/src/tools/clippy/clippy_lints/src/semicolon_block.rs new file mode 100644 index 000000000..8f1d1490e --- /dev/null +++ b/src/tools/clippy/clippy_lints/src/semicolon_block.rs @@ -0,0 +1,137 @@ +use clippy_utils::diagnostics::{multispan_sugg_with_applicability, span_lint_and_then}; +use rustc_errors::Applicability; +use rustc_hir::{Block, Expr, ExprKind, Stmt, StmtKind}; +use rustc_lint::{LateContext, LateLintPass, LintContext}; +use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::Span; + +declare_clippy_lint! { + /// ### What it does + /// + /// Suggests moving the semicolon after a block to the inside of the block, after its last + /// expression. + /// + /// ### 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 + /// + /// Suggests moving the semicolon from a block's final expression outside of 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_stmt(&mut self, cx: &LateContext<'_>, stmt: &Stmt<'_>) { + match stmt.kind { + StmtKind::Expr(Expr { + kind: ExprKind::Block(block, _), + .. + }) if !block.span.from_expansion() => { + let Block { + expr: None, + stmts: [.., stmt], + .. + } = block else { return }; + let &Stmt { + kind: StmtKind::Semi(expr), + span, + .. + } = stmt else { return }; + semicolon_outside_block(cx, block, expr, span); + }, + StmtKind::Semi(Expr { + kind: ExprKind::Block(block @ Block { expr: Some(tail), .. }, _), + .. + }) if !block.span.from_expansion() => semicolon_inside_block(cx, block, tail, stmt.span), + _ => (), + } + } +} + +fn semicolon_inside_block(cx: &LateContext<'_>, block: &Block<'_>, tail: &Expr<'_>, semi_span: Span) { + let insert_span = tail.span.source_callsite().shrink_to_hi(); + let remove_span = semi_span.with_lo(block.span.hi()); + + span_lint_and_then( + cx, + SEMICOLON_INSIDE_BLOCK, + semi_span, + "consider moving the `;` inside the block for consistent formatting", + |diag| { + multispan_sugg_with_applicability( + diag, + "put the `;` here", + Applicability::MachineApplicable, + [(remove_span, String::new()), (insert_span, ";".to_owned())], + ); + }, + ); +} + +fn semicolon_outside_block(cx: &LateContext<'_>, block: &Block<'_>, tail_stmt_expr: &Expr<'_>, semi_span: Span) { + let insert_span = block.span.with_lo(block.span.hi()); + // account for macro calls + let semi_span = cx.sess().source_map().stmt_span(semi_span, block.span); + let remove_span = semi_span.with_lo(tail_stmt_expr.span.source_callsite().hi()); + + span_lint_and_then( + cx, + SEMICOLON_OUTSIDE_BLOCK, + block.span, + "consider moving the `;` outside the block for consistent formatting", + |diag| { + multispan_sugg_with_applicability( + diag, + "put the `;` here", + Applicability::MachineApplicable, + [(remove_span, String::new()), (insert_span, ";".to_owned())], + ); + }, + ); +} |