//! Contains utility functions to generate suggestions.
#![deny(clippy::missing_docs_in_private_items)]
-use crate::utils::{higher, in_macro, snippet, snippet_opt};
+use crate::utils::{higher, in_macro_or_desugar, snippet, snippet_opt, snippet_with_macro_callsite};
use matches::matches;
use rustc::hir;
use rustc::lint::{EarlyContext, LateContext, LintContext};
pub fn hir_opt(cx: &LateContext<'_, '_>, expr: &hir::Expr) -> Option<Self> {
snippet_opt(cx, expr.span).map(|snippet| {
let snippet = Cow::Owned(snippet);
- match expr.node {
- hir::ExprKind::AddrOf(..)
- | hir::ExprKind::Box(..)
- | hir::ExprKind::Closure(.., _)
- | hir::ExprKind::If(..)
- | hir::ExprKind::Unary(..)
- | hir::ExprKind::Match(..) => Sugg::MaybeParen(snippet),
- hir::ExprKind::Continue(..)
- | hir::ExprKind::Yield(..)
- | hir::ExprKind::Array(..)
- | hir::ExprKind::Block(..)
- | hir::ExprKind::Break(..)
- | hir::ExprKind::Call(..)
- | hir::ExprKind::Field(..)
- | hir::ExprKind::Index(..)
- | hir::ExprKind::InlineAsm(..)
- | hir::ExprKind::Lit(..)
- | hir::ExprKind::Loop(..)
- | hir::ExprKind::MethodCall(..)
- | hir::ExprKind::Path(..)
- | hir::ExprKind::Repeat(..)
- | hir::ExprKind::Ret(..)
- | hir::ExprKind::Struct(..)
- | hir::ExprKind::Tup(..)
- | hir::ExprKind::While(..)
- | hir::ExprKind::Err => Sugg::NonParen(snippet),
- hir::ExprKind::Assign(..) => Sugg::BinOp(AssocOp::Assign, snippet),
- hir::ExprKind::AssignOp(op, ..) => Sugg::BinOp(hirbinop2assignop(op), snippet),
- hir::ExprKind::Binary(op, ..) => Sugg::BinOp(AssocOp::from_ast_binop(higher::binop(op.node)), snippet),
- hir::ExprKind::Cast(..) => Sugg::BinOp(AssocOp::As, snippet),
- hir::ExprKind::Type(..) => Sugg::BinOp(AssocOp::Colon, snippet),
- }
+ Self::hir_from_snippet(expr, snippet)
})
}
default: &'a str,
applicability: &mut Applicability,
) -> Self {
- if *applicability != Applicability::Unspecified && in_macro(expr.span) {
+ if *applicability != Applicability::Unspecified && in_macro_or_desugar(expr.span) {
*applicability = Applicability::MaybeIncorrect;
}
Self::hir_opt(cx, expr).unwrap_or_else(|| {
})
}
+ /// Same as `hir`, but will use the pre expansion span if the `expr` was in a macro.
+ pub fn hir_with_macro_callsite(cx: &LateContext<'_, '_>, expr: &hir::Expr, default: &'a str) -> Self {
+ let snippet = snippet_with_macro_callsite(cx, expr.span, default);
+
+ Self::hir_from_snippet(expr, snippet)
+ }
+
+ /// Generate a suggestion for an expression with the given snippet. This is used by the `hir_*`
+ /// function variants of `Sugg`, since these use different snippet functions.
+ fn hir_from_snippet(expr: &hir::Expr, snippet: Cow<'a, str>) -> Self {
+ match expr.node {
+ hir::ExprKind::AddrOf(..)
+ | hir::ExprKind::Box(..)
+ | hir::ExprKind::Closure(.., _)
+ | hir::ExprKind::Unary(..)
+ | hir::ExprKind::Match(..) => Sugg::MaybeParen(snippet),
+ hir::ExprKind::Continue(..)
+ | hir::ExprKind::Yield(..)
+ | hir::ExprKind::Array(..)
+ | hir::ExprKind::Block(..)
+ | hir::ExprKind::Break(..)
+ | hir::ExprKind::Call(..)
+ | hir::ExprKind::Field(..)
+ | hir::ExprKind::Index(..)
+ | hir::ExprKind::InlineAsm(..)
+ | hir::ExprKind::Lit(..)
+ | hir::ExprKind::Loop(..)
+ | hir::ExprKind::MethodCall(..)
+ | hir::ExprKind::Path(..)
+ | hir::ExprKind::Repeat(..)
+ | hir::ExprKind::Ret(..)
+ | hir::ExprKind::Struct(..)
+ | hir::ExprKind::Tup(..)
+ | hir::ExprKind::While(..)
+ | hir::ExprKind::DropTemps(_)
+ | hir::ExprKind::Err => Sugg::NonParen(snippet),
+ hir::ExprKind::Assign(..) => Sugg::BinOp(AssocOp::Assign, snippet),
+ hir::ExprKind::AssignOp(op, ..) => Sugg::BinOp(hirbinop2assignop(op), snippet),
+ hir::ExprKind::Binary(op, ..) => Sugg::BinOp(AssocOp::from_ast_binop(higher::binop(op.node)), snippet),
+ hir::ExprKind::Cast(..) => Sugg::BinOp(AssocOp::As, snippet),
+ hir::ExprKind::Type(..) => Sugg::BinOp(AssocOp::Colon, snippet),
+ }
+ }
+
/// Prepare a suggestion from an expression.
pub fn ast(cx: &EarlyContext<'_>, expr: &ast::Expr, default: &'a str) -> Self {
use syntax::ast::RangeLimits;
| ast::ExprKind::Closure(..)
| ast::ExprKind::If(..)
| ast::ExprKind::IfLet(..)
- | ast::ExprKind::ObsoleteInPlace(..)
| ast::ExprKind::Unary(..)
| ast::ExprKind::Match(..) => Sugg::MaybeParen(snippet),
ast::ExprKind::Async(..)
| ast::ExprKind::Array(..)
| ast::ExprKind::While(..)
| ast::ExprKind::WhileLet(..)
+ | ast::ExprKind::Await(..)
| ast::ExprKind::Err => Sugg::NonParen(snippet),
ast::ExprKind::Range(.., RangeLimits::HalfOpen) => Sugg::BinOp(AssocOp::DotDot, snippet),
ast::ExprKind::Range(.., RangeLimits::Closed) => Sugg::BinOp(AssocOp::DotDotEq, snippet),
make_unop("&mut *", self)
}
+ /// Convenience method to transform suggestion into a return call
+ pub fn make_return(self) -> Sugg<'static> {
+ Sugg::NonParen(Cow::Owned(format!("return {}", self)))
+ }
+
+ /// Convenience method to transform suggestion into a block
+ /// where the suggestion is a trailing expression
+ pub fn blockify(self) -> Sugg<'static> {
+ Sugg::NonParen(Cow::Owned(format!("{{ {} }}", self)))
+ }
+
/// Convenience method to create the `<lhs>..<rhs>` or `<lhs>...<rhs>`
/// suggestion.
#[allow(dead_code)]
}
}
- /// Add parenthesis to any expression that might need them. Suitable to the
- /// `self` argument of
- /// a method call (eg. to build `bar.foo()` or `(1 + 2).foo()`).
+ /// Adds parenthesis to any expression that might need them. Suitable to the
+ /// `self` argument of a method call
+ /// (e.g., to build `bar.foo()` or `(1 + 2).foo()`).
pub fn maybe_par(self) -> Self {
match self {
Sugg::NonParen(..) => self,
- // (x) and (x).y() both don't need additional parens
+ // `(x)` and `(x).y()` both don't need additional parens.
Sugg::MaybeParen(sugg) => {
if sugg.starts_with('(') && sugg.ends_with(')') {
Sugg::MaybeParen(sugg)
/// Helper type to display either `foo` or `(foo)`.
struct ParenHelper<T> {
- /// Whether parenthesis are needed.
+ /// `true` if parentheses are needed.
paren: bool,
/// The main thing to display.
wrapped: T,
}
impl<T> ParenHelper<T> {
- /// Build a `ParenHelper`.
+ /// Builds a `ParenHelper`.
fn new(paren: bool, wrapped: T) -> Self {
Self { paren, wrapped }
}
}
}
-/// Build the string for `<op><expr>` adding parenthesis when necessary.
+/// Builds the string for `<op><expr>` adding parenthesis when necessary.
///
/// For convenience, the operator is taken as a string because all unary
/// operators have the same
Sugg::MaybeParen(format!("{}{}", op, expr.maybe_par()).into())
}
-/// Build the string for `<lhs> <op> <rhs>` adding parenthesis when necessary.
+/// Builds the string for `<lhs> <op> <rhs>` adding parenthesis when necessary.
///
/// Precedence of shift operator relative to other arithmetic operation is
/// often confusing so
/// parenthesis will always be added for a mix of these.
pub fn make_assoc(op: AssocOp, lhs: &Sugg<'_>, rhs: &Sugg<'_>) -> Sugg<'static> {
- /// Whether the operator is a shift operator `<<` or `>>`.
+ /// Returns `true` if the operator is a shift operator `<<` or `>>`.
fn is_shift(op: &AssocOp) -> bool {
matches!(*op, AssocOp::ShiftLeft | AssocOp::ShiftRight)
}
- /// Whether the operator is a arithmetic operator (`+`, `-`, `*`, `/`, `%`).
+ /// Returns `true` if the operator is a arithmetic operator
+ /// (i.e., `+`, `-`, `*`, `/`, `%`).
fn is_arith(op: &AssocOp) -> bool {
matches!(
*op,
)
}
- /// Whether the operator `op` needs parenthesis with the operator `other`
- /// in the direction
- /// `dir`.
+ /// Returns `true` if the operator `op` needs parenthesis with the operator
+ /// `other` in the direction `dir`.
fn needs_paren(op: &AssocOp, other: &AssocOp, dir: Associativity) -> bool {
other.precedence() < op.precedence()
|| (other.precedence() == op.precedence()
rhs
),
AssocOp::Assign => format!("{} = {}", lhs, rhs),
- AssocOp::ObsoleteInPlace => format!("in ({}) {}", lhs, rhs),
AssocOp::AssignOp(op) => format!("{} {}= {}", lhs, token_to_string(&token::BinOp(op)), rhs),
AssocOp::As => format!("{} as {}", lhs, rhs),
AssocOp::DotDot => format!("{}..{}", lhs, rhs),
Right,
}
-/// Return the associativity/fixity of an operator. The difference with
-/// `AssocOp::fixity` is that
-/// an operator can be both left and right associative (such as `+`:
-/// `a + b + c == (a + b) + c == a + (b + c)`.
+/// Returns the associativity/fixity of an operator. The difference with
+/// `AssocOp::fixity` is that an operator can be both left and right associative
+/// (such as `+`: `a + b + c == (a + b) + c == a + (b + c)`.
///
/// Chained `as` and explicit `:` type coercion never need inner parenthesis so
/// they are considered
use syntax::util::parser::AssocOp::*;
match *op {
- ObsoleteInPlace | Assign | AssignOp(_) => Associativity::Right,
+ Assign | AssignOp(_) => Associativity::Right,
Add | BitAnd | BitOr | BitXor | LAnd | LOr | Multiply | As | Colon => Associativity::Both,
Divide | Equal | Greater | GreaterEqual | Less | LessEqual | Modulus | NotEqual | ShiftLeft | ShiftRight
| Subtract => Associativity::Left,
}
}
-/// Convert a `hir::BinOp` to the corresponding assigning binary operator.
+/// Converts a `hir::BinOp` to the corresponding assigning binary operator.
fn hirbinop2assignop(op: hir::BinOp) -> AssocOp {
use syntax::parse::token::BinOpToken::*;
})
}
-/// Convert an `ast::BinOp` to the corresponding assigning binary operator.
+/// Converts an `ast::BinOp` to the corresponding assigning binary operator.
fn astbinop2assignop(op: ast::BinOp) -> AssocOp {
use syntax::ast::BinOpKind::*;
use syntax::parse::token::BinOpToken;
})
}
-/// Return the indentation before `span` if there are nothing but `[ \t]`
+/// Returns the indentation before `span` if there are nothing but `[ \t]`
/// before it on its line.
fn indentation<'a, T: LintContext<'a>>(cx: &T, span: Span) -> Option<String> {
let lo = cx.sess().source_map().lookup_char_pos(span.lo());
if let Some(line) = lo.file.get_line(lo.line - 1 /* line numbers in `Loc` are 1-based */) {
if let Some((pos, _)) = line.char_indices().find(|&(_, c)| c != ' ' && c != '\t') {
- // we can mix char and byte positions here because we only consider `[ \t]`
+ // We can mix char and byte positions here because we only consider `[ \t]`.
if lo.col == CharPos(pos) {
Some(line[..pos].into())
} else {
if let Some(indent) = indentation(cx, item) {
let span = item.with_hi(item.lo());
- self.span_suggestion_with_applicability(span, msg, format!("{}\n{}", attr, indent), applicability);
+ self.span_suggestion(span, msg, format!("{}\n{}", attr, indent), applicability);
}
}
})
.collect::<String>();
- self.span_suggestion_with_applicability(span, msg, format!("{}\n{}", new_item, indent), applicability);
+ self.span_suggestion(span, msg, format!("{}\n{}", new_item, indent), applicability);
}
}
}
}
- self.span_suggestion_with_applicability(remove_span, msg, String::new(), applicability);
+ self.span_suggestion(remove_span, msg, String::new(), applicability);
+ }
+}
+
+#[cfg(test)]
+mod test {
+ use super::Sugg;
+ use std::borrow::Cow;
+
+ const SUGGESTION: Sugg<'static> = Sugg::NonParen(Cow::Borrowed("function_call()"));
+
+ #[test]
+ fn make_return_transform_sugg_into_a_return_call() {
+ assert_eq!("return function_call()", SUGGESTION.make_return().to_string());
+ }
+
+ #[test]
+ fn blockify_transforms_sugg_into_a_block() {
+ assert_eq!("{ function_call() }", SUGGESTION.blockify().to_string());
}
}
projects / rust.git / blobdiff