1 // Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution.
4 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
5 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
7 // option. This file may not be copied, modified, or distributed
8 // except according to those terms.
10 use crate::utils::{is_direct_expn_of, is_expn_of, match_def_path, opt_def_id, paths, resolve_node, span_lint};
11 use if_chain::if_chain;
13 use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
14 use rustc::{declare_tool_lint, lint_array};
15 use syntax::ast::LitKind;
16 use syntax::ext::quote::rt::Span;
19 /// **What it does:** Checks for missing parameters in `panic!`.
21 /// **Why is this bad?** Contrary to the `format!` family of macros, there are
22 /// two forms of `panic!`: if there are no parameters given, the first argument
23 /// is not a format string and used literally. So while `format!("{}")` will
24 /// fail to compile, `panic!("{}")` will not.
26 /// **Known problems:** None.
30 /// panic!("This `panic!` is probably missing a parameter there: {}");
32 declare_clippy_lint! {
35 "missing parameters in `panic!` calls"
38 /// **What it does:** Checks for usage of `unimplemented!`.
40 /// **Why is this bad?** This macro should not be present in production code
42 /// **Known problems:** None.
48 declare_clippy_lint! {
51 "`unimplemented!` should not be present in production code"
56 impl LintPass for Pass {
57 fn get_lints(&self) -> LintArray {
58 lint_array!(PANIC_PARAMS, UNIMPLEMENTED)
62 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
63 fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
65 if let ExprKind::Block(ref block, _) = expr.node;
66 if let Some(ref ex) = block.expr;
67 if let ExprKind::Call(ref fun, ref params) = ex.node;
68 if let ExprKind::Path(ref qpath) = fun.node;
69 if let Some(fun_def_id) = opt_def_id(resolve_node(cx, qpath, fun.hir_id));
70 if match_def_path(cx.tcx, fun_def_id, &paths::BEGIN_PANIC);
73 if is_expn_of(expr.span, "unimplemented").is_some() {
74 let span = get_outer_span(expr);
75 span_lint(cx, UNIMPLEMENTED, span,
76 "`unimplemented` should not be present in production code");
78 match_panic(params, expr, cx);
85 fn get_outer_span(expr: &Expr) -> Span {
87 if let Some(first) = expr.span.ctxt().outer().expn_info();
88 if let Some(second) = first.call_site.ctxt().outer().expn_info();
97 fn match_panic(params: &P<[Expr]>, expr: &Expr, cx: &LateContext<'_, '_>) {
99 if let ExprKind::Lit(ref lit) = params[0].node;
100 if is_direct_expn_of(expr.span, "panic").is_some();
101 if let LitKind::Str(ref string, _) = lit.node;
102 let string = string.as_str().replace("{{", "").replace("}}", "");
103 if let Some(par) = string.find('{');
104 if string[par..].contains('}');
105 if params[0].span.source_callee().is_none();
106 if params[0].span.lo() != params[0].span.hi();
108 span_lint(cx, PANIC_PARAMS, params[0].span,
109 "you probably are missing some parameter in your format string");