Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

[bool_assert_comparaison] improve suggestion #7612

Closed
wants to merge 8 commits into from
Closed

[bool_assert_comparaison] improve suggestion #7612

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
90117a0
improve suggestion for bool_assert_comparaison
ABouttefeux Sep 1, 2021
e696ba2
add extraction of fmt parameter
ABouttefeux Sep 6, 2021
3d17ede
extract the formaing string and the values
ABouttefeux Sep 21, 2021
b079660
change to a structure for parsing assert macro
ABouttefeux Sep 22, 2021
5f5ea41
remove the format_string_expr from the FormatArgsExpn
ABouttefeux Sep 22, 2021
256e6c5
change based on review and debug_assert
ABouttefeux Oct 15, 2021
073dd99
add assert to the parsing
ABouttefeux Oct 15, 2021
103ac52
reomove unecessary import
ABouttefeux Oct 21, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
80 changes: 58 additions & 22 deletions clippy_lints/src/bool_assert_comparison.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,4 +1,6 @@
use clippy_utils::{diagnostics::span_lint_and_sugg, higher, is_direct_expn_of, ty::implements_trait};
use clippy_utils::{
diagnostics::span_lint_and_sugg, higher::AssertExpn, is_direct_expn_of, source, ty::implements_trait,
};
use rustc_ast::ast::LitKind;
use rustc_errors::Applicability;
use rustc_hir::{Expr, ExprKind, Lit};
Expand Down Expand Up @@ -30,14 +32,19 @@ declare_clippy_lint! {

declare_lint_pass!(BoolAssertComparison => [BOOL_ASSERT_COMPARISON]);

fn is_bool_lit(e: &Expr<'_>) -> bool {
matches!(
e.kind,
fn bool_lit(e: &Expr<'_>) -> Option<bool> {
match e.kind {
ExprKind::Lit(Lit {
node: LitKind::Bool(_),
..
})
) && !e.span.from_expansion()
node: LitKind::Bool(b), ..
}) => {
if e.span.from_expansion() {
None
} else {
Some(b)
}
},
_ => None,
}
}

fn is_impl_not_trait_with_bool_out(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> bool {
Expand Down Expand Up @@ -68,19 +75,25 @@ impl<'tcx> LateLintPass<'tcx> for BoolAssertComparison {
let macros = ["assert_eq", "debug_assert_eq"];
let inverted_macros = ["assert_ne", "debug_assert_ne"];

for mac in macros.iter().chain(inverted_macros.iter()) {
for (mac, is_eq) in macros
.iter()
.map(|el| (el, true))
.chain(inverted_macros.iter().map(|el| (el, false)))
{
if let Some(span) = is_direct_expn_of(expr.span, mac) {
if let Some(args) = higher::extract_assert_macro_args(expr) {
if let [a, b, ..] = args[..] {
let nb_bool_args = is_bool_lit(a) as usize + is_bool_lit(b) as usize;

if nb_bool_args != 1 {
// If there are two boolean arguments, we definitely don't understand
// what's going on, so better leave things as is...
//
// Or there is simply no boolean and then we can leave things as is!
return;
}
if let Some(parse_assert) = AssertExpn::parse(expr) {
if let [a, b] = parse_assert.assert_arguments()[..] {
let (lit_value, other_expr) = match (bool_lit(a), bool_lit(b)) {
(Some(lit), None) => (lit, b),
(None, Some(lit)) => (lit, a),
_ => {
// If there are two boolean arguments, we definitely don't understand
// what's going on, so better leave things as is...
//
// Or there is simply no boolean and then we can leave things as is!
return;
},
};

if !is_impl_not_trait_with_bool_out(cx, a) || !is_impl_not_trait_with_bool_out(cx, b) {
// At this point the expression which is not a boolean
Expand All @@ -90,14 +103,37 @@ impl<'tcx> LateLintPass<'tcx> for BoolAssertComparison {
}

let non_eq_mac = &mac[..mac.len() - 3];
let mut applicability = Applicability::MachineApplicable;
let expr_string = if lit_value ^ is_eq {
format!("!({})", source::snippet(cx, other_expr.span, ""))
camsteffen marked this conversation as resolved.
Show resolved Hide resolved
} else {
source::snippet(cx, other_expr.span, "").to_string()
};
let fmt_args = parse_assert.format_arguments(cx, &mut applicability);
let arg_span = match &fmt_args[..] {
[] => None,
[a] => Some(a.to_string()),
_ => {
let mut args = fmt_args[0].to_string();
for el in &fmt_args[1..] {
args.push_str(&format!(", {}", el));
}
Some(args)
},
};
let suggestion = if let Some(spans) = arg_span {
format!("{}!({}, {})", non_eq_mac, expr_string, spans)
} else {
format!("{}!({})", non_eq_mac, expr_string)
};
span_lint_and_sugg(
cx,
BOOL_ASSERT_COMPARISON,
span,
&format!("used `{}!` with a literal bool", mac),
"replace it with",
format!("{}!(..)", non_eq_mac),
Applicability::MaybeIncorrect,
suggestion,
applicability,
);
return;
}
Expand Down
4 changes: 2 additions & 2 deletions clippy_lints/src/eq_op.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,7 @@ use clippy_utils::diagnostics::{multispan_sugg, span_lint, span_lint_and_then};
use clippy_utils::source::snippet;
use clippy_utils::ty::{implements_trait, is_copy};
use clippy_utils::{
ast_utils::is_useless_with_eq_exprs, eq_expr_value, higher, in_macro, is_expn_of, is_in_test_function,
ast_utils::is_useless_with_eq_exprs, eq_expr_value, higher::AssertExpn, in_macro, is_expn_of, is_in_test_function,
};
use if_chain::if_chain;
use rustc_errors::Applicability;
Expand Down Expand Up @@ -79,7 +79,7 @@ impl<'tcx> LateLintPass<'tcx> for EqOp {
if_chain! {
if is_expn_of(stmt.span, amn).is_some();
if let StmtKind::Semi(matchexpr) = stmt.kind;
if let Some(macro_args) = higher::extract_assert_macro_args(matchexpr);
if let Some(macro_args) = AssertExpn::parse(matchexpr).map(|v| v.assert_arguments());
if macro_args.len() == 2;
let (lhs, rhs) = (macro_args[0], macro_args[1]);
if eq_expr_value(cx, lhs, rhs);
Expand Down
4 changes: 2 additions & 2 deletions clippy_lints/src/mutable_debug_assertion.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
use clippy_utils::diagnostics::span_lint;
use clippy_utils::{higher, is_direct_expn_of};
use clippy_utils::{higher::AssertExpn, is_direct_expn_of};
use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
use rustc_hir::{BorrowKind, Expr, ExprKind, MatchSource, Mutability};
use rustc_lint::{LateContext, LateLintPass};
Expand Down Expand Up @@ -39,7 +39,7 @@ impl<'tcx> LateLintPass<'tcx> for DebugAssertWithMutCall {
fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
for dmn in &DEBUG_MACRO_NAMES {
if is_direct_expn_of(e.span, dmn).is_some() {
if let Some(macro_args) = higher::extract_assert_macro_args(e) {
if let Some(macro_args) = AssertExpn::parse(e).map(|v| v.assert_arguments()) {
for arg in macro_args {
let mut visitor = MutArgVisitor::new(cx);
visitor.visit_expr(arg);
Expand Down
192 changes: 158 additions & 34 deletions clippy_utils/src/higher.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,16 +3,19 @@
#![deny(clippy::missing_docs_in_private_items)]

use crate::ty::is_type_diagnostic_item;
use crate::{is_expn_of, last_path_segment, match_def_path, paths};
use crate::{is_expn_of, last_path_segment, match_def_path, paths, source::snippet_with_applicability};
use if_chain::if_chain;
use rustc_ast::ast::{self, LitKind};
use rustc_errors::Applicability;
use rustc_hir as hir;
use rustc_hir::{
Arm, Block, BorrowKind, Expr, ExprKind, HirId, LoopSource, MatchSource, Node, Pat, QPath, StmtKind, UnOp,
};
use rustc_lint::LateContext;
use rustc_span::{sym, symbol, ExpnKind, Span, Symbol};

use std::borrow::Cow;

/// The essential nodes of a desugared for loop as well as the entire span:
/// `for pat in arg { body }` becomes `(pat, arg, body)`. Return `(pat, arg, body, span)`.
pub struct ForLoop<'tcx> {
Expand Down Expand Up @@ -418,56 +421,177 @@ pub fn binop(op: hir::BinOpKind) -> ast::BinOpKind {
}
}

/// Extract args from an assert-like macro.
/// Currently working with:
/// - `assert!`, `assert_eq!` and `assert_ne!`
/// - `debug_assert!`, `debug_assert_eq!` and `debug_assert_ne!`
/// For example:
/// `assert!(expr)` will return `Some([expr])`
/// `debug_assert_eq!(a, b)` will return `Some([a, b])`
pub fn extract_assert_macro_args<'tcx>(e: &'tcx Expr<'tcx>) -> Option<Vec<&'tcx Expr<'tcx>>> {
/// Try to match the AST for a pattern that contains a match, for example when two args are
/// compared
fn ast_matchblock(matchblock_expr: &'tcx Expr<'tcx>) -> Option<Vec<&Expr<'_>>> {
if_chain! {
if let ExprKind::Match(headerexpr, _, _) = &matchblock_expr.kind;
if let ExprKind::Tup([lhs, rhs]) = &headerexpr.kind;
if let ExprKind::AddrOf(BorrowKind::Ref, _, lhs) = lhs.kind;
if let ExprKind::AddrOf(BorrowKind::Ref, _, rhs) = rhs.kind;
then {
return Some(vec![lhs, rhs]);
/// Kind of assert macros
pub enum AssertExpnKind<'tcx> {
/// Boolean macro like `assert!` or `debug_assert!`
Bool(&'tcx Expr<'tcx>),
/// Comparaison maacro like `assert_eq!`, `assert_ne!`, `debug_assert_eq!` or `debug_assert_ne!`
Eq(&'tcx Expr<'tcx>, &'tcx Expr<'tcx>),
}

/// A parsed
/// `assert!`, `assert_eq!` or `assert_ne!`,
/// `debug_assert!`, `debug_assert_eq!` or `debug_assert_ne!`
/// macro.
pub struct AssertExpn<'tcx> {
/// Kind of assert macro
pub kind: AssertExpnKind<'tcx>,
/// The format argument passed at the end of the macro
pub format_arg: Option<FormatArgsExpn<'tcx>>,
/// is a debug macro
pub is_debug: bool,
}
camsteffen marked this conversation as resolved.
Show resolved Hide resolved

impl<'tcx> AssertExpn<'tcx> {
/// Extract args from an assert-like macro.
/// Currently working with:
/// - `assert!`, `assert_eq!` and `assert_ne!`
/// - `debug_assert!`, `debug_assert_eq!` and `debug_assert_ne!`
/// For example:
/// `assert!(expr)` will return `Some(AssertExpn { first_assert_argument: expr,
/// second_assert_argument: None, format_arg:None })` `debug_assert_eq!(a, b)` will return
/// `Some(AssertExpn { first_assert_argument: a, second_assert_argument: Some(b),
/// format_arg:None })`
pub fn parse(e: &'tcx Expr<'tcx>) -> Option<Self> {
if let ExprKind::Block(block, _) = e.kind {
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Consider doing something like this as a first step

if let ExpnKind::Macro(_, name) = expr.span.ctxt().outer_expn_data().kind;
match *name.as_str() {
    "assert" | "debug_assert" => ..,
    "assert_eq" | "debug_assert_eq" => ..,
}

if block.stmts.len() == 1 {
if let StmtKind::Semi(matchexpr) = block.stmts.get(0)?.kind {
// debug macros with two args: `debug_assert_{ne, eq}` (e.g., `assert_ne!(a, b)`)
if_chain! {
if let ExprKind::Block(matchblock,_) = matchexpr.kind;
if let Some(matchblock_expr) = matchblock.expr;
then {
return Self::ast_matchblock(matchblock_expr, true);
}
}
// debug macros with unique arg: `debug_assert!` (e.g., `debug_assert!(some_condition)`)
return Self::ast_ifblock(matchexpr, true);
}
} else if let Some(matchblock_expr) = block.expr {
// macros with two args: `assert_{ne, eq}` (e.g., `assert_ne!(a, b)`)
return Self::ast_matchblock(matchblock_expr, false);
}
} else {
// assert! macro
return Self::ast_ifblock(e, false);
}
None
}

if let ExprKind::Block(block, _) = e.kind {
if block.stmts.len() == 1 {
if let StmtKind::Semi(matchexpr) = block.stmts.get(0)?.kind {
// macros with unique arg: `{debug_}assert!` (e.g., `debug_assert!(some_condition)`)
/// Try to parse the pattern for an assert macro with a single argument like `{debug_}assert!`
fn ast_ifblock(ifblock_expr: &'tcx Expr<'tcx>, is_debug: bool) -> Option<Self> {
if_chain! {
if let Some(If { cond, then, .. }) = If::hir(ifblock_expr);
if let ExprKind::Unary(UnOp::Not, condition) = cond.kind;
then {
if_chain! {
if let Some(If { cond, .. }) = If::hir(matchexpr);
if let ExprKind::Unary(UnOp::Not, condition) = cond.kind;
if let ExprKind::Block(block, _) = then.kind;
if let Some(begin_panic_fmt_block) = block.expr;
if let ExprKind::Block(block,_) = begin_panic_fmt_block.kind;
if let Some(expr) = block.expr;
if let ExprKind::Call(_, args_begin_panic_fmt) = expr.kind;
if !args_begin_panic_fmt.is_empty();
if let ExprKind::AddrOf(_, _, arg) = args_begin_panic_fmt[0].kind;
if let Some(format_arg_expn) = FormatArgsExpn::parse(arg);
then {
return Some(vec![condition]);
return Some(Self {
kind: AssertExpnKind::Bool(condition),
format_arg: Some(format_arg_expn),
is_debug
});
}
}
return Some(Self {
kind: AssertExpnKind::Bool(condition),
format_arg: None,
is_debug
});
}
}
None
}

// debug macros with two args: `debug_assert_{ne, eq}` (e.g., `assert_ne!(a, b)`)
/// Try to match the AST for a pattern that contains a match, for example when two args are
/// compared
fn ast_matchblock(matchblock_expr: &'tcx Expr<'tcx>, is_debug: bool) -> Option<Self> {
if_chain! {
if let ExprKind::Match(headerexpr, arms, _) = &matchblock_expr.kind;
if let ExprKind::Tup([lhs, rhs]) = &headerexpr.kind;
if let ExprKind::AddrOf(BorrowKind::Ref, _, lhs) = lhs.kind;
if let ExprKind::AddrOf(BorrowKind::Ref, _, rhs) = rhs.kind;
then {
if_chain! {
if let ExprKind::Block(matchblock,_) = matchexpr.kind;
if let Some(matchblock_expr) = matchblock.expr;
if !arms.is_empty();
if let ExprKind::Block(Block{expr: Some(if_expr),..},_) = arms[0].body.kind;
if let ExprKind::If(_, if_block, _) = if_expr.kind;
if let ExprKind::Block(Block{stmts: stmts_if_block,..},_) = if_block.kind;
if stmts_if_block.len() >= 2;
if let StmtKind::Expr(call_assert_failed)
| StmtKind::Semi(call_assert_failed) = stmts_if_block[1].kind;
if let ExprKind::Call(_, args_assert_failed) = call_assert_failed.kind;
if args_assert_failed.len() >= 4;
if let ExprKind::Call(_, [arg, ..]) = args_assert_failed[3].kind;
if let Some(format_arg_expn) = FormatArgsExpn::parse(arg);
then {
return ast_matchblock(matchblock_expr);
return Some(AssertExpn {
kind: AssertExpnKind::Eq(lhs,rhs),
format_arg: Some(format_arg_expn),
is_debug,
});
}
}
return Some(AssertExpn {
kind: AssertExpnKind::Eq(lhs,rhs),
format_arg: None,
is_debug,
});
}
} else if let Some(matchblock_expr) = block.expr {
// macros with two args: `assert_{ne, eq}` (e.g., `assert_ne!(a, b)`)
return ast_matchblock(matchblock_expr);
}
None
}

/// Gives the argument in the comparaison as a vector leaving the format
pub fn assert_arguments(&self) -> Vec<&'tcx Expr<'tcx>> {
match self.kind {
AssertExpnKind::Bool(expr) => {
vec![expr]
},
AssertExpnKind::Eq(lhs, rhs) => {
vec![lhs, rhs]
},
}
}

/// Gives the argument passed to the macro as a string
pub fn all_arguments_string(
&self,
cx: &LateContext<'_>,
applicability: &mut Applicability,
) -> Vec<Cow<'static, str>> {
let mut vec_arg = vec![];
for arg in self.assert_arguments() {
vec_arg.push(snippet_with_applicability(cx, arg.span, "..", applicability));
}
vec_arg.append(&mut self.format_arguments(cx, applicability));
vec_arg
}

/// Returns only the format agruments
pub fn format_arguments(&self, cx: &LateContext<'_>, applicability: &mut Applicability) -> Vec<Cow<'static, str>> {
let mut vec_arg = vec![];
if let Some(ref fmt_arg) = self.format_arg {
vec_arg.push(snippet_with_applicability(
cx,
fmt_arg.format_string_span,
"..",
applicability,
));
for arg in &fmt_arg.value_args {
vec_arg.push(snippet_with_applicability(cx, arg.span, "..", applicability));
}
}
vec_arg
}
None
}

/// A parsed `format!` expansion
Expand Down
Loading