use crate::utils::{is_direct_expn_of, is_expn_of, match_function_call, paths, span_lint}; use if_chain::if_chain; use rustc_ast::ast::LitKind; use rustc_hir::{Expr, ExprKind}; use rustc_lint::{LateContext, LateLintPass}; use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::Span; declare_clippy_lint! { /// **What it does:** Checks for missing parameters in `panic!`. /// /// **Why is this bad?** Contrary to the `format!` family of macros, there are /// two forms of `panic!`: if there are no parameters given, the first argument /// is not a format string and used literally. So while `format!("{}")` will /// fail to compile, `panic!("{}")` will not. /// /// **Known problems:** None. /// /// **Example:** /// ```no_run /// panic!("This `panic!` is probably missing a parameter there: {}"); /// ``` pub PANIC_PARAMS, style, "missing parameters in `panic!` calls" } declare_clippy_lint! { /// **What it does:** Checks for usage of `panic!`. /// /// **Why is this bad?** `panic!` will stop the execution of the executable /// /// **Known problems:** None. /// /// **Example:** /// ```no_run /// panic!("even with a good reason"); /// ``` pub PANIC, restriction, "usage of the `panic!` macro" } declare_clippy_lint! { /// **What it does:** Checks for usage of `unimplemented!`. /// /// **Why is this bad?** This macro should not be present in production code /// /// **Known problems:** None. /// /// **Example:** /// ```no_run /// unimplemented!(); /// ``` pub UNIMPLEMENTED, restriction, "`unimplemented!` should not be present in production code" } declare_clippy_lint! { /// **What it does:** Checks for usage of `todo!`. /// /// **Why is this bad?** This macro should not be present in production code /// /// **Known problems:** None. /// /// **Example:** /// ```no_run /// todo!(); /// ``` pub TODO, restriction, "`todo!` should not be present in production code" } declare_clippy_lint! { /// **What it does:** Checks for usage of `unreachable!`. /// /// **Why is this bad?** This macro can cause code to panic /// /// **Known problems:** None. /// /// **Example:** /// ```no_run /// unreachable!(); /// ``` pub UNREACHABLE, restriction, "`unreachable!` should not be present in production code" } declare_lint_pass!(PanicUnimplemented => [PANIC_PARAMS, UNIMPLEMENTED, UNREACHABLE, TODO, PANIC]); impl<'tcx> LateLintPass<'tcx> for PanicUnimplemented { fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { if_chain! { if let ExprKind::Block(ref block, _) = expr.kind; if let Some(ref ex) = block.expr; if let Some(params) = match_function_call(cx, ex, &paths::BEGIN_PANIC); if params.len() == 1; then { if is_expn_of(expr.span, "unimplemented").is_some() { let span = get_outer_span(expr); span_lint(cx, UNIMPLEMENTED, span, "`unimplemented` should not be present in production code"); } else if is_expn_of(expr.span, "todo").is_some() { let span = get_outer_span(expr); span_lint(cx, TODO, span, "`todo` should not be present in production code"); } else if is_expn_of(expr.span, "unreachable").is_some() { let span = get_outer_span(expr); span_lint(cx, UNREACHABLE, span, "`unreachable` should not be present in production code"); } else if is_expn_of(expr.span, "panic").is_some() { let span = get_outer_span(expr); span_lint(cx, PANIC, span, "`panic` should not be present in production code"); match_panic(params, expr, cx); } } } } } fn get_outer_span(expr: &Expr<'_>) -> Span { if_chain! { if expr.span.from_expansion(); let first = expr.span.ctxt().outer_expn_data(); if first.call_site.from_expansion(); let second = first.call_site.ctxt().outer_expn_data(); then { second.call_site } else { expr.span } } } fn match_panic(params: &[Expr<'_>], expr: &Expr<'_>, cx: &LateContext<'_>) { if_chain! { if let ExprKind::Lit(ref lit) = params[0].kind; if is_direct_expn_of(expr.span, "panic").is_some(); if let LitKind::Str(ref string, _) = lit.node; let string = string.as_str().replace("{{", "").replace("}}", ""); if let Some(par) = string.find('{'); if string[par..].contains('}'); if params[0].span.source_callee().is_none(); if params[0].span.lo() != params[0].span.hi(); then { span_lint(cx, PANIC_PARAMS, params[0].span, "you probably are missing some parameter in your format string"); } } }