use clippy_utils::last_path_segment;
use clippy_utils::macros::root_macro_call_first_node;
use clippy_utils::source::{indent_of, snippet};
-use rustc_errors::{Applicability, Diagnostic};
+use rustc_errors::Applicability;
use rustc_hir::{Expr, ExprKind, QPath, TyKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
let Some(macro_call) = root_macro_call_first_node(cx, expr) else { return; };
let Some(VecArgs::Repeat(elem, len)) = VecArgs::hir(cx, expr) else { return; };
let Some(symbol) = new_reference_call(cx, elem) else { return; };
- let lint_span = macro_call.span;
- let symbol_name = symbol.as_str();
- let len_snippet = snippet(cx, len.span, "..");
- let elem_snippet = elem_snippet(cx, elem, symbol_name);
- let indentation = indent_of(cx, lint_span).unwrap_or(0);
- let lint_suggestions =
- construct_lint_suggestions(lint_span, symbol_name, &elem_snippet, len_snippet.as_ref(), indentation);
-
- emit_lint(cx, symbol, lint_span, &lint_suggestions);
+
+ emit_lint(cx, symbol, macro_call.span, elem, len);
}
}
struct LintSuggestion {
- span: Span,
message: String,
- suggestion: String,
- applicability: Applicability,
-}
-
-impl LintSuggestion {
- fn span_suggestion(&self, diag: &mut Diagnostic) {
- diag.span_suggestion(self.span, &self.message, &self.suggestion, self.applicability);
- }
+ snippet: String,
}
fn construct_lint_suggestions(
+ cx: &LateContext<'_>,
span: Span,
symbol_name: &str,
- elem_snippet: &str,
- len_snippet: &str,
- indentation: usize,
+ elem: &Expr<'_>,
+ len: &Expr<'_>,
) -> Vec<LintSuggestion> {
+ let len_snippet = snippet(cx, len.span, "..");
+ let elem_snippet = elem_snippet(cx, elem, symbol_name);
+ let indentation = indent_of(cx, span).unwrap_or(0);
let indentation = " ".repeat(indentation);
- let loop_init_suggestion = loop_init_suggestion(elem_snippet, len_snippet, &indentation);
- let extract_suggestion = extract_suggestion(elem_snippet, len_snippet, &indentation);
+ let loop_init_suggestion = loop_init_suggestion(&elem_snippet, len_snippet.as_ref(), &indentation);
+ let extract_suggestion = extract_suggestion(&elem_snippet, len_snippet.as_ref(), &indentation);
vec![
LintSuggestion {
- span,
message: format!("consider initializing each `{symbol_name}` element individually"),
- suggestion: loop_init_suggestion,
- applicability: Applicability::Unspecified,
+ snippet: loop_init_suggestion,
},
LintSuggestion {
- span,
message: format!(
"or if this is intentional, consider extracting the `{symbol_name}` initialization to a variable"
),
- suggestion: extract_suggestion,
- applicability: Applicability::Unspecified,
+ snippet: extract_suggestion,
},
]
}
fn elem_snippet(cx: &LateContext<'_>, elem: &Expr<'_>, symbol_name: &str) -> String {
- let mut elem_snippet = snippet(cx, elem.span, "..").to_string();
+ let elem_snippet = snippet(cx, elem.span, "..").to_string();
if elem_snippet.contains('\n') {
- let reference_initialization = format!("{symbol_name}::new");
- // This string must be found in `elem_snippet`, otherwise we won't be constructing the snippet in
- // the first place.
- let reference_initialization_end =
- elem_snippet.find(&reference_initialization).unwrap() + reference_initialization.len();
- elem_snippet.replace_range(reference_initialization_end.., "..");
+ let reference_creation = format!("{symbol_name}::new");
+ let (code_until_reference_creation, _right) = elem_snippet.split_once(&reference_creation).unwrap();
+
+ return format!("{code_until_reference_creation}{reference_creation}(..)");
}
+
elem_snippet
}
)
}
-fn emit_lint(cx: &LateContext<'_>, symbol: Symbol, lint_span: Span, lint_suggestions: &[LintSuggestion]) {
+fn emit_lint(cx: &LateContext<'_>, symbol: Symbol, lint_span: Span, elem: &Expr<'_>, len: &Expr<'_>) {
let symbol_name = symbol.as_str();
span_lint_and_then(
lint_span,
&format!("calling `{symbol_name}::new` in `vec![elem; len]`"),
|diag| {
+ let suggestions = construct_lint_suggestions(cx, lint_span, symbol_name, elem, len);
+
diag.note(format!("each element will point to the same `{symbol_name}` instance"));
- lint_suggestions
- .iter()
- .for_each(|suggestion| suggestion.span_suggestion(diag));
+ suggestions.iter().for_each(|suggestion| {
+ diag.span_suggestion(
+ lint_span,
+ &suggestion.message,
+ &suggestion.snippet,
+ Applicability::Unspecified,
+ );
+ });
},
);
}