#![deny(clippy::missing_docs_in_private_items)]
-use crate::{is_expn_of, match_def_path, paths};
+use crate::ty::is_type_diagnostic_item;
+use crate::{is_expn_of, last_path_segment, 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, BorrowKind, Expr, ExprKind, HirId, LoopSource, MatchSource, Node, Pat, QPath, StmtKind, UnOp,
+};
use rustc_lint::LateContext;
-use rustc_span::{sym, ExpnKind, Span, Symbol};
+use rustc_span::{sym, symbol, ExpnKind, Span, Symbol};
/// 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)`.
if_else,
) = expr.kind
{
- let hir = cx.tcx.hir();
- let mut iter = hir.parent_iter(expr.hir_id);
+ let mut iter = cx.tcx.hir().parent_iter(expr.hir_id);
if let Some((_, Node::Block(Block { stmts: [], .. }))) = iter.next() {
if let Some((
_,
}
}
}
+
+ /// Returns a vector of `FormatArgsArg`.
+ pub fn args(&self) -> Option<Vec<FormatArgsArg<'tcx>>> {
+ if let Some(expr) = self.fmt_expr {
+ if_chain! {
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, expr) = expr.kind;
+ if let ExprKind::Array(exprs) = expr.kind;
+ then {
+ exprs.iter().map(|fmt| {
+ if_chain! {
+ // struct `core::fmt::rt::v1::Argument`
+ if let ExprKind::Struct(_, fields, _) = fmt.kind;
+ if let Some(position_field) = fields.iter().find(|f| f.ident.name == sym::position);
+ if let ExprKind::Lit(lit) = &position_field.expr.kind;
+ if let LitKind::Int(position, _) = lit.node;
+ then {
+ let i = usize::try_from(position).unwrap();
+ Some(FormatArgsArg { value: self.value_args[i], arg: &self.args[i], fmt: Some(fmt) })
+ } else {
+ None
+ }
+ }
+ }).collect()
+ } else {
+ None
+ }
+ }
+ } else {
+ Some(
+ self.value_args
+ .iter()
+ .zip(self.args.iter())
+ .map(|(value, arg)| FormatArgsArg { value, arg, fmt: None })
+ .collect(),
+ )
+ }
+ }
+}
+
+/// Type representing a `FormatArgsExpn`'s format arguments
+pub struct FormatArgsArg<'tcx> {
+ /// An element of `value_args` according to `position`
+ pub value: &'tcx Expr<'tcx>,
+ /// An element of `args` according to `position`
+ pub arg: &'tcx Expr<'tcx>,
+ /// An element of `fmt_expn`
+ pub fmt: Option<&'tcx Expr<'tcx>>,
+}
+
+impl<'tcx> FormatArgsArg<'tcx> {
+ /// Returns true if any formatting parameters are used that would have an effect on strings,
+ /// like `{:+2}` instead of just `{}`.
+ pub fn has_string_formatting(&self) -> bool {
+ self.fmt.map_or(false, |fmt| {
+ // `!` because these conditions check that `self` is unformatted.
+ !if_chain! {
+ // struct `core::fmt::rt::v1::Argument`
+ if let ExprKind::Struct(_, fields, _) = fmt.kind;
+ if let Some(format_field) = fields.iter().find(|f| f.ident.name == sym::format);
+ // struct `core::fmt::rt::v1::FormatSpec`
+ if let ExprKind::Struct(_, subfields, _) = format_field.expr.kind;
+ let mut precision_found = false;
+ let mut width_found = false;
+ if subfields.iter().all(|field| {
+ match field.ident.name {
+ sym::precision => {
+ precision_found = true;
+ if let ExprKind::Path(ref precision_path) = field.expr.kind {
+ last_path_segment(precision_path).ident.name == sym::Implied
+ } else {
+ false
+ }
+ }
+ sym::width => {
+ width_found = true;
+ if let ExprKind::Path(ref width_qpath) = field.expr.kind {
+ last_path_segment(width_qpath).ident.name == sym::Implied
+ } else {
+ false
+ }
+ }
+ _ => true,
+ }
+ });
+ if precision_found && width_found;
+ then { true } else { false }
+ }
+ })
+ }
+
+ /// Returns true if the argument is formatted using `Display::fmt`.
+ pub fn is_display(&self) -> bool {
+ if_chain! {
+ if let ExprKind::Call(_, [_, format_field]) = self.arg.kind;
+ if let ExprKind::Path(QPath::Resolved(_, path)) = format_field.kind;
+ if let [.., t, _] = path.segments;
+ if t.ident.name == sym::Display;
+ then { true } else { false }
+ }
+ }
}
/// Checks if a `let` statement is from a `for` loop desugaring.
false
}
+
+/// A parsed `panic!` expansion
+pub struct PanicExpn<'tcx> {
+ /// Span of `panic!(..)`
+ pub call_site: Span,
+ /// Inner `format_args!` expansion
+ pub format_args: FormatArgsExpn<'tcx>,
+}
+
+impl PanicExpn<'tcx> {
+ /// Parses an expanded `panic!` invocation
+ pub fn parse(expr: &'tcx Expr<'tcx>) -> Option<Self> {
+ if_chain! {
+ if let ExprKind::Block(block, _) = expr.kind;
+ if let Some(init) = block.expr;
+ if let ExprKind::Call(_, [format_args]) = init.kind;
+ let expn_data = expr.span.ctxt().outer_expn_data();
+ if let ExprKind::AddrOf(_, _, format_args) = format_args.kind;
+ if let Some(format_args) = FormatArgsExpn::parse(format_args);
+ then {
+ Some(PanicExpn {
+ call_site: expn_data.call_site,
+ format_args,
+ })
+ } else {
+ None
+ }
+ }
+ }
+}
+
+/// 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),
+}
+
+/// 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()?))
+ }
+ }
+ 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);
+ }
+ _ => (),
+ }
+ }
+ None
+}
projects / rust.git / blobdiff