diff --git a/clippy_lints/src/assertions_on_constants.rs b/clippy_lints/src/assertions_on_constants.rs index d1be15ba1663..79b584990f88 100644 --- a/clippy_lints/src/assertions_on_constants.rs +++ b/clippy_lints/src/assertions_on_constants.rs @@ -1,9 +1,11 @@ -use rustc::hir::{Expr, ExprKind}; +use crate::consts::{constant, Constant}; +use crate::utils::{is_direct_expn_of, is_expn_of, match_qpath, span_help_and_lint}; +use if_chain::if_chain; +use rustc::hir::*; use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass}; use rustc::{declare_lint_pass, declare_tool_lint}; - -use crate::consts::{constant, Constant}; -use crate::utils::{is_direct_expn_of, is_expn_of, span_help_and_lint}; +use syntax::ast::LitKind; +use syntax::source_map::symbol::LocalInternedString; declare_clippy_lint! { /// **What it does:** Checks for `assert!(true)` and `assert!(false)` calls. @@ -63,7 +65,93 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) { if assert_span.from_expansion() { return; } - lint_assert_cb(false); + if let Some((panic_message, is_true)) = assert_with_message(&cx, e) { + if is_true { + span_help_and_lint( + cx, + ASSERTIONS_ON_CONSTANTS, + e.span, + "`assert!(true)` will be optimized out by the compiler", + "remove it", + ); + } else if panic_message.starts_with("assertion failed: ") { + span_help_and_lint( + cx, + ASSERTIONS_ON_CONSTANTS, + e.span, + "`assert!(false)` should probably be replaced", + "use `panic!()` or `unreachable!()`", + ); + } else { + span_help_and_lint( + cx, + ASSERTIONS_ON_CONSTANTS, + e.span, + &format!("`assert!(false, \"{}\")` should probably be replaced", panic_message,), + &format!( + "use `panic!(\"{}\")` or `unreachable!(\"{}\")`", + panic_message, panic_message, + ), + ); + } + } } } } + +// fn get_assert_args(snip: String) -> Option> { +// +// } + +fn assert_with_message<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) -> Option<(LocalInternedString, bool)> { + if_chain! { + if let ExprKind::Match(ref expr, ref arms, MatchSource::IfDesugar { contains_else_clause: false }) = expr.kind; + // match expr + if let ExprKind::DropTemps(ref expr) = expr.kind; + if let ExprKind::Unary(UnOp::UnNot, ref expr) = expr.kind; + //if let ExprKind::Lit(ref lit) = expr.kind; + if let Some((Constant::Bool(is_true), _)) = constant(cx, cx.tables, expr); + //if is_true; + // match arms + // arm 1 pattern + if let PatKind::Lit(ref lit_expr) = arms[0].pat.kind; + if let ExprKind::Lit(ref lit) = lit_expr.kind; + if let LitKind::Bool(true) = lit.node; + //if let LitKind::Bool(true) = lit1.node; + // arm 1 block + if let ExprKind::Block(ref block1, _) = arms[0].body.kind; + if let Some(trailing_expr1) = &block1.expr; + if block1.stmts.len() == 0; + // + if let ExprKind::Block(ref actual_block1, _) = trailing_expr1.kind; + if let Some(block1_expr) = &actual_block1.expr; + // function call + if let ExprKind::Call(ref func, ref args) = block1_expr.kind; + if let ExprKind::Path(ref path) = func.kind; + // ["{{root}}", "std", "rt", "begin_panic"] does not work + if match_qpath(path, &["$crate", "rt", "begin_panic"]); + // arguments + if args.len() == 2; + if let ExprKind::Lit(ref lit) = args[0].kind; + if let LitKind::Str(ref s, _) = lit.node; + let panic_message = s.as_str(); // bind the panic message + if let ExprKind::AddrOf(MutImmutable, ref inner) = args[1].kind; + if let ExprKind::Tup(ref elements) = inner.kind; + if elements.len() == 3; + if let ExprKind::Lit(ref lit1) = elements[0].kind; + if let LitKind::Str(ref s1, _) = lit1.node; + if let ExprKind::Lit(ref lit2) = elements[1].kind; + if let LitKind::Int(_, _) = lit2.node; + if let ExprKind::Lit(ref lit3) = elements[2].kind; + if let LitKind::Int(_, _) = lit3.node; + // arm 2 block + if let PatKind::Wild = arms[1].pat.kind; + if let ExprKind::Block(ref block2, _) = arms[1].body.kind; + if let None = &block2.expr; + if block2.stmts.len() == 0; + then { + return Some((panic_message, is_true)); + } + } + return None; +} diff --git a/tests/ui/assertions_on_constants.rs b/tests/ui/assertions_on_constants.rs index aee6cc505abd..0d9fe636bf9b 100644 --- a/tests/ui/assertions_on_constants.rs +++ b/tests/ui/assertions_on_constants.rs @@ -16,6 +16,7 @@ fn main() { const C: bool = false; assert!(C); + assert!(C, "C message"); debug_assert!(true); // Don't lint this, since there is no better way for expressing "Only panic in debug mode". diff --git a/tests/ui/assertions_on_constants.stderr b/tests/ui/assertions_on_constants.stderr index c22da856975c..84a2533ccdcc 100644 --- a/tests/ui/assertions_on_constants.stderr +++ b/tests/ui/assertions_on_constants.stderr @@ -23,13 +23,13 @@ LL | assert!(true, "true message"); | = help: remove it -error: `assert!(false)` should probably be replaced +error: `assert!(false, "false message")` should probably be replaced --> $DIR/assertions_on_constants.rs:12:5 | LL | assert!(false, "false message"); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | - = help: use `panic!()` or `unreachable!()` + = help: use `panic!("false message")` or `unreachable!("false message")` error: `assert!(true)` will be optimized out by the compiler --> $DIR/assertions_on_constants.rs:15:5 @@ -47,8 +47,16 @@ LL | assert!(C); | = help: use `panic!()` or `unreachable!()` +error: `assert!(false, "C message")` should probably be replaced + --> $DIR/assertions_on_constants.rs:19:5 + | +LL | assert!(C, "C message"); + | ^^^^^^^^^^^^^^^^^^^^^^^^ + | + = help: use `panic!("C message")` or `unreachable!("C message")` + error: `assert!(true)` will be optimized out by the compiler - --> $DIR/assertions_on_constants.rs:20:5 + --> $DIR/assertions_on_constants.rs:21:5 | LL | debug_assert!(true); | ^^^^^^^^^^^^^^^^^^^^ @@ -56,5 +64,5 @@ LL | debug_assert!(true); = help: remove it = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info) -error: aborting due to 7 previous errors +error: aborting due to 8 previous errors