-//! This module contains functions that retrieves specifiec elements.
+//! This module contains functions that retrieve specific elements.
#![deny(clippy::missing_docs_in_private_items)]
+use crate::ty::is_type_diagnostic_item;
use crate::{is_expn_of, match_def_path, paths};
use if_chain::if_chain;
use rustc_ast::ast::{self, LitKind};
use rustc_hir as hir;
-use rustc_hir::{Arm, Block, BorrowKind, Expr, ExprKind, LoopSource, MatchSource, Node, Pat, StmtKind, UnOp};
+use rustc_hir::{Arm, Block, Expr, ExprKind, HirId, LoopSource, MatchSource, Node, Pat, QPath};
use rustc_lint::LateContext;
-use rustc_span::{sym, ExpnKind, Span, Symbol};
+use rustc_span::{sym, symbol, Span};
/// 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 arg: &'tcx hir::Expr<'tcx>,
/// `for` loop body
pub body: &'tcx hir::Expr<'tcx>,
+ /// Compare this against `hir::Destination.target`
+ pub loop_id: HirId,
/// entire `for` loop span
pub span: Span,
}
impl<'tcx> ForLoop<'tcx> {
- #[inline]
/// Parses a desugared `for` loop
pub fn hir(expr: &Expr<'tcx>) -> Option<Self> {
if_chain! {
- if let hir::ExprKind::Match(iterexpr, arms, hir::MatchSource::ForLoopDesugar) = expr.kind;
- if let Some(first_arm) = arms.get(0);
- if let hir::ExprKind::Call(_, iterargs) = iterexpr.kind;
- if let Some(first_arg) = iterargs.get(0);
- if iterargs.len() == 1 && arms.len() == 1 && first_arm.guard.is_none();
- if let hir::ExprKind::Loop(block, ..) = first_arm.body.kind;
- if block.expr.is_none();
- if let [ _, _, ref let_stmt, ref body ] = *block.stmts;
- if let hir::StmtKind::Local(local) = let_stmt.kind;
- if let hir::StmtKind::Expr(body_expr) = body.kind;
+ if let hir::ExprKind::DropTemps(e) = expr.kind;
+ if let hir::ExprKind::Match(iterexpr, [arm], hir::MatchSource::ForLoopDesugar) = e.kind;
+ if let hir::ExprKind::Call(_, [arg]) = iterexpr.kind;
+ if let hir::ExprKind::Loop(block, ..) = arm.body.kind;
+ if let [stmt] = &*block.stmts;
+ if let hir::StmtKind::Expr(e) = stmt.kind;
+ if let hir::ExprKind::Match(_, [_, some_arm], _) = e.kind;
+ if let hir::PatKind::Struct(_, [field], _) = some_arm.pat.kind;
then {
return Some(Self {
- pat: &*local.pat,
- arg: first_arg,
- body: body_expr,
- span: first_arm.span
+ pat: field.pat,
+ arg,
+ body: some_arm.body,
+ loop_id: arm.body.hir_id,
+ span: expr.span.ctxt().outer_expn_data().call_site,
});
}
}
pub fn hir(cx: &LateContext<'_>, expr: &Expr<'hir>) -> Option<Self> {
if let ExprKind::If(
Expr {
- kind: ExprKind::Let(let_pat, let_expr, _),
+ kind:
+ ExprKind::Let(hir::Let {
+ pat: let_pat,
+ init: let_expr,
+ ..
+ }),
..
},
if_then,
hir::ExprKind::Call(path, args)
if matches!(
path.kind,
- hir::ExprKind::Path(hir::QPath::LangItem(hir::LangItem::RangeInclusiveNew, _))
+ hir::ExprKind::Path(hir::QPath::LangItem(hir::LangItem::RangeInclusiveNew, ..))
) =>
{
Some(Range {
})
},
hir::ExprKind::Struct(path, fields, None) => match &path {
- hir::QPath::LangItem(hir::LangItem::RangeFull, _) => Some(Range {
+ hir::QPath::LangItem(hir::LangItem::RangeFull, ..) => Some(Range {
start: None,
end: None,
limits: ast::RangeLimits::HalfOpen,
}),
- hir::QPath::LangItem(hir::LangItem::RangeFrom, _) => Some(Range {
+ hir::QPath::LangItem(hir::LangItem::RangeFrom, ..) => Some(Range {
start: Some(get_field("start", fields)?),
end: None,
limits: ast::RangeLimits::HalfOpen,
}),
- hir::QPath::LangItem(hir::LangItem::Range, _) => Some(Range {
+ hir::QPath::LangItem(hir::LangItem::Range, ..) => Some(Range {
start: Some(get_field("start", fields)?),
end: Some(get_field("end", fields)?),
limits: ast::RangeLimits::HalfOpen,
}),
- hir::QPath::LangItem(hir::LangItem::RangeToInclusive, _) => Some(Range {
+ hir::QPath::LangItem(hir::LangItem::RangeToInclusive, ..) => Some(Range {
start: None,
end: Some(get_field("end", fields)?),
limits: ast::RangeLimits::Closed,
}),
- hir::QPath::LangItem(hir::LangItem::RangeTo, _) => Some(Range {
+ hir::QPath::LangItem(hir::LangItem::RangeTo, ..) => Some(Range {
start: None,
end: Some(get_field("end", fields)?),
limits: ast::RangeLimits::HalfOpen,
return if match_def_path(cx, fun_def_id, &paths::VEC_FROM_ELEM) && args.len() == 2 {
// `vec![elem; size]` case
Some(VecArgs::Repeat(&args[0], &args[1]))
- }
- else if match_def_path(cx, fun_def_id, &paths::SLICE_INTO_VEC) && args.len() == 1 {
+ } else if match_def_path(cx, fun_def_id, &paths::SLICE_INTO_VEC) && args.len() == 1 {
// `vec![a, b, c]` case
if_chain! {
if let hir::ExprKind::Box(boxed) = args[0].kind;
}
None
- }
- else if match_def_path(cx, fun_def_id, &paths::VEC_NEW) && args.is_empty() {
+ } else if match_def_path(cx, fun_def_id, &paths::VEC_NEW) && args.is_empty() {
Some(VecArgs::Vec(&[]))
- }
- else {
+ } else {
None
};
}
kind:
ExprKind::If(
Expr {
- kind: ExprKind::Let(let_pat, let_expr, _),
+ kind:
+ ExprKind::Let(hir::Let {
+ pat: let_pat,
+ init: let_expr,
+ ..
+ }),
..
},
if_then,
}
}
-/// 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]);
- }
- }
- 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)`)
- if_chain! {
- if let Some(If { cond, .. }) = If::hir(matchexpr);
- if let ExprKind::Unary(UnOp::Not, condition) = cond.kind;
- then {
- return Some(vec![condition]);
- }
- }
-
- // 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 ast_matchblock(matchblock_expr);
- }
- }
- }
- } 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
-}
-
-/// A parsed `format!` expansion
-pub struct FormatExpn<'tcx> {
- /// Span of `format!(..)`
- pub call_site: Span,
- /// Inner `format_args!` expansion
- pub format_args: FormatArgsExpn<'tcx>,
+/// A parsed `Vec` initialization expression
+#[derive(Clone, Copy)]
+pub enum VecInitKind {
+ /// `Vec::new()`
+ New,
+ /// `Vec::default()` or `Default::default()`
+ Default,
+ /// `Vec::with_capacity(123)`
+ WithLiteralCapacity(u64),
+ /// `Vec::with_capacity(slice.len())`
+ WithExprCapacity(HirId),
}
-impl FormatExpn<'tcx> {
- /// Parses an expanded `format!` invocation
- pub fn parse(expr: &'tcx Expr<'tcx>) -> Option<Self> {
- if_chain! {
- if let ExprKind::Block(block, _) = expr.kind;
- if let [stmt] = block.stmts;
- if let StmtKind::Local(local) = stmt.kind;
- if let Some(init) = local.init;
- if let ExprKind::Call(_, [format_args]) = init.kind;
- let expn_data = expr.span.ctxt().outer_expn_data();
- if let ExpnKind::Macro(_, sym::format) = expn_data.kind;
- if let Some(format_args) = FormatArgsExpn::parse(format_args);
- then {
- Some(FormatExpn {
- call_site: expn_data.call_site,
- format_args,
- })
- } else {
- None
- }
- }
- }
-}
-
-/// A parsed `format_args!` expansion
-pub struct FormatArgsExpn<'tcx> {
- /// Span of the first argument, the format string
- pub format_string_span: Span,
- /// Values passed after the format string
- pub value_args: Vec<&'tcx Expr<'tcx>>,
-
- /// String literal expressions which represent the format string split by "{}"
- pub format_string_parts: &'tcx [Expr<'tcx>],
- /// Symbols corresponding to [`Self::format_string_parts`]
- pub format_string_symbols: Vec<Symbol>,
- /// Expressions like `ArgumentV1::new(arg0, Debug::fmt)`
- pub args: &'tcx [Expr<'tcx>],
- /// The final argument passed to `Arguments::new_v1_formatted`, if applicable
- pub fmt_expr: Option<&'tcx Expr<'tcx>>,
-}
-
-impl FormatArgsExpn<'tcx> {
- /// Parses an expanded `format_args!` or `format_args_nl!` invocation
- pub fn parse(expr: &'tcx Expr<'tcx>) -> Option<Self> {
- if_chain! {
- if let ExpnKind::Macro(_, name) = expr.span.ctxt().outer_expn_data().kind;
- let name = name.as_str();
- if name.ends_with("format_args") || name.ends_with("format_args_nl");
-
- if let ExprKind::Match(inner_match, [arm], _) = expr.kind;
-
- // `match match`, if you will
- if let ExprKind::Match(args, [inner_arm], _) = inner_match.kind;
- if let ExprKind::Tup(value_args) = args.kind;
- if let Some(value_args) = value_args
- .iter()
- .map(|e| match e.kind {
- ExprKind::AddrOf(_, _, e) => Some(e),
- _ => None,
- })
- .collect();
- if let ExprKind::Array(args) = inner_arm.body.kind;
-
- if let ExprKind::Block(Block { stmts: [], expr: Some(expr), .. }, _) = arm.body.kind;
- if let ExprKind::Call(_, call_args) = expr.kind;
- if let Some((strs_ref, fmt_expr)) = match call_args {
- // Arguments::new_v1
- [strs_ref, _] => Some((strs_ref, None)),
- // Arguments::new_v1_formatted
- [strs_ref, _, fmt_expr] => Some((strs_ref, Some(fmt_expr))),
- _ => None,
- };
- if let ExprKind::AddrOf(BorrowKind::Ref, _, strs_arr) = strs_ref.kind;
- if let ExprKind::Array(format_string_parts) = strs_arr.kind;
- if let Some(format_string_symbols) = format_string_parts
- .iter()
- .map(|e| {
- if let ExprKind::Lit(lit) = &e.kind {
- if let LitKind::Str(symbol, _style) = lit.node {
- return Some(symbol);
+/// Checks if given expression is an initialization of `Vec` and returns its kind.
+pub fn get_vec_init_kind<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Option<VecInitKind> {
+ if let ExprKind::Call(func, args) = expr.kind {
+ match func.kind {
+ ExprKind::Path(QPath::TypeRelative(ty, name))
+ if is_type_diagnostic_item(cx, cx.typeck_results().node_type(ty.hir_id), sym::Vec) =>
+ {
+ if name.ident.name == sym::new {
+ return Some(VecInitKind::New);
+ } else if name.ident.name == symbol::kw::Default {
+ return Some(VecInitKind::Default);
+ } else if name.ident.name.as_str() == "with_capacity" {
+ let arg = args.get(0)?;
+ if_chain! {
+ if let ExprKind::Lit(lit) = &arg.kind;
+ if let LitKind::Int(num, _) = lit.node;
+ then {
+ return Some(VecInitKind::WithLiteralCapacity(num.try_into().ok()?));
}
}
- None
- })
- .collect();
- then {
- Some(FormatArgsExpn {
- format_string_span: strs_ref.span,
- value_args,
- format_string_parts,
- format_string_symbols,
- args,
- fmt_expr,
- })
- } else {
- None
- }
- }
- }
-}
-
-/// Checks if a `let` statement is from a `for` loop desugaring.
-pub fn is_from_for_desugar(local: &hir::Local<'_>) -> bool {
- // This will detect plain for-loops without an actual variable binding:
- //
- // ```
- // for x in some_vec {
- // // do stuff
- // }
- // ```
- if_chain! {
- if let Some(expr) = local.init;
- if let hir::ExprKind::Match(_, _, hir::MatchSource::ForLoopDesugar) = expr.kind;
- then {
- return true;
+ return Some(VecInitKind::WithExprCapacity(arg.hir_id));
+ }
+ },
+ ExprKind::Path(QPath::Resolved(_, path))
+ if match_def_path(cx, path.res.opt_def_id()?, &paths::DEFAULT_TRAIT_METHOD)
+ && is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::Vec) =>
+ {
+ return Some(VecInitKind::Default);
+ },
+ _ => (),
}
}
-
- // This detects a variable binding in for loop to avoid `let_unit_value`
- // lint (see issue #1964).
- //
- // ```
- // for _ in vec![()] {
- // // anything
- // }
- // ```
- if let hir::LocalSource::ForLoopDesugar = local.source {
- return true;
- }
-
- false
+ None
}
projects / rust.git / blobdiff