//! This module contains functions for retrieve the original AST from lowered
//! `hir`.
-#![deny(missing_docs_in_private_items)]
+#![deny(clippy::missing_docs_in_private_items)]
+use crate::utils::{is_expn_of, match_def_path, match_qpath, paths};
use if_chain::if_chain;
-use rustc::{hir, ty};
use rustc::lint::LateContext;
+use rustc::{hir, ty};
use syntax::ast;
-use crate::utils::{is_expn_of, match_def_path, match_qpath, opt_def_id, paths, resolve_node};
-/// Convert a hir binary operator to the corresponding `ast` type.
+/// Converts a hir binary operator to the corresponding `ast` type.
+#[must_use]
pub fn binop(op: hir::BinOpKind) -> ast::BinOpKind {
match op {
hir::BinOpKind::Eq => ast::BinOpKind::Eq,
/// Higher a `hir` range to something similar to `ast::ExprKind::Range`.
pub fn range<'a, 'b, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'b hir::Expr) -> Option<Range<'b>> {
+ /// Finds the field named `name` in the field. Always return `Some` for
+ /// convenience.
+ fn get_field<'c>(name: &str, fields: &'c [hir::Field]) -> Option<&'c hir::Expr> {
+ let expr = &fields.iter().find(|field| field.ident.name.as_str() == name)?.expr;
- let def_path = match cx.tables.expr_ty(expr).sty {
+ Some(expr)
+ }
+
+ let def_path = match cx.tables.expr_ty(expr).kind {
ty::Adt(def, _) => cx.tcx.def_path(def.did),
_ => return None,
};
if def_path.data.len() != 3 {
return None;
}
- if def_path.data.get(0)?.data.as_interned_str() != "ops" {
+ if def_path.data.get(0)?.data.as_interned_str().as_symbol() != sym!(ops) {
return None;
}
- if def_path.data.get(1)?.data.as_interned_str() != "range" {
+ if def_path.data.get(1)?.data.as_interned_str().as_symbol() != sym!(range) {
return None;
}
let type_name = def_path.data.get(2)?.data.as_interned_str();
return None;
}
- /// Find the field named `name` in the field. Always return `Some` for
- /// convenience.
- fn get_field<'a>(name: &str, fields: &'a [hir::Field]) -> Option<&'a hir::Expr> {
- let expr = &fields.iter().find(|field| field.ident.name == name)?.expr;
-
- Some(expr)
- }
-
// The range syntax is expanded to literal paths starting with `core` or `std`
// depending on
// `#[no_std]`. Testing both instead of resolving the paths.
- match expr.node {
+ match expr.kind {
hir::ExprKind::Path(ref path) => {
if match_qpath(path, &paths::RANGE_FULL_STD) || match_qpath(path, &paths::RANGE_FULL) {
Some(Range {
None
}
},
- hir::ExprKind::Call(ref path, ref args) => if let hir::ExprKind::Path(ref path) = path.node {
- if match_qpath(path, &paths::RANGE_INCLUSIVE_STD_NEW) || match_qpath(path, &paths::RANGE_INCLUSIVE_NEW) {
+ hir::ExprKind::Call(ref path, ref args) => {
+ if let hir::ExprKind::Path(ref path) = path.kind {
+ if match_qpath(path, &paths::RANGE_INCLUSIVE_STD_NEW) || match_qpath(path, &paths::RANGE_INCLUSIVE_NEW)
+ {
+ Some(Range {
+ start: Some(&args[0]),
+ end: Some(&args[1]),
+ limits: ast::RangeLimits::Closed,
+ })
+ } else {
+ None
+ }
+ } else {
+ None
+ }
+ },
+ hir::ExprKind::Struct(ref path, ref fields, None) => {
+ if match_qpath(path, &paths::RANGE_FROM_STD) || match_qpath(path, &paths::RANGE_FROM) {
+ Some(Range {
+ start: Some(get_field("start", fields)?),
+ end: None,
+ limits: ast::RangeLimits::HalfOpen,
+ })
+ } else if match_qpath(path, &paths::RANGE_STD) || match_qpath(path, &paths::RANGE) {
+ Some(Range {
+ start: Some(get_field("start", fields)?),
+ end: Some(get_field("end", fields)?),
+ limits: ast::RangeLimits::HalfOpen,
+ })
+ } else if match_qpath(path, &paths::RANGE_TO_INCLUSIVE_STD) || match_qpath(path, &paths::RANGE_TO_INCLUSIVE)
+ {
Some(Range {
- start: Some(&args[0]),
- end: Some(&args[1]),
+ start: None,
+ end: Some(get_field("end", fields)?),
limits: ast::RangeLimits::Closed,
})
+ } else if match_qpath(path, &paths::RANGE_TO_STD) || match_qpath(path, &paths::RANGE_TO) {
+ Some(Range {
+ start: None,
+ end: Some(get_field("end", fields)?),
+ limits: ast::RangeLimits::HalfOpen,
+ })
} else {
None
}
- } else {
- None
- },
- hir::ExprKind::Struct(ref path, ref fields, None) => if match_qpath(path, &paths::RANGE_FROM_STD)
- || match_qpath(path, &paths::RANGE_FROM)
- {
- Some(Range {
- start: Some(get_field("start", fields)?),
- end: None,
- limits: ast::RangeLimits::HalfOpen,
- })
- } else if match_qpath(path, &paths::RANGE_STD) || match_qpath(path, &paths::RANGE) {
- Some(Range {
- start: Some(get_field("start", fields)?),
- end: Some(get_field("end", fields)?),
- limits: ast::RangeLimits::HalfOpen,
- })
- } else if match_qpath(path, &paths::RANGE_TO_INCLUSIVE_STD) || match_qpath(path, &paths::RANGE_TO_INCLUSIVE) {
- Some(Range {
- start: None,
- end: Some(get_field("end", fields)?),
- limits: ast::RangeLimits::Closed,
- })
- } else if match_qpath(path, &paths::RANGE_TO_STD) || match_qpath(path, &paths::RANGE_TO) {
- Some(Range {
- start: None,
- end: Some(get_field("end", fields)?),
- limits: ast::RangeLimits::HalfOpen,
- })
- } else {
- None
},
_ => None,
}
}
-/// Checks if a `let` decl is from a `for` loop desugaring.
-pub fn is_from_for_desugar(decl: &hir::Decl) -> bool {
+/// 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
+ // // do stuff
// }
// ```
if_chain! {
- if let hir::DeclKind::Local(ref loc) = decl.node;
- if let Some(ref expr) = loc.init;
- if let hir::ExprKind::Match(_, _, hir::MatchSource::ForLoopDesugar) = expr.node;
+ if let Some(ref expr) = local.init;
+ if let hir::ExprKind::Match(_, _, hir::MatchSource::ForLoopDesugar) = expr.kind;
then {
return true;
}
//
// ```
// for _ in vec![()] {
- // // anything
+ // // anything
// }
// ```
- if_chain! {
- if let hir::DeclKind::Local(ref loc) = decl.node;
- if let hir::LocalSource::ForLoopDesugar = loc.source;
- then {
- return true;
- }
+ if let hir::LocalSource::ForLoopDesugar = local.source {
+ return true;
}
false
/// `for pat in arg { body }` becomes `(pat, arg, body)`.
pub fn for_loop(expr: &hir::Expr) -> Option<(&hir::Pat, &hir::Expr, &hir::Expr)> {
if_chain! {
- if let hir::ExprKind::Match(ref iterexpr, ref arms, hir::MatchSource::ForLoopDesugar) = expr.node;
- if let hir::ExprKind::Call(_, ref iterargs) = iterexpr.node;
+ if let hir::ExprKind::Match(ref iterexpr, ref arms, hir::MatchSource::ForLoopDesugar) = expr.kind;
+ if let hir::ExprKind::Call(_, ref iterargs) = iterexpr.kind;
if iterargs.len() == 1 && arms.len() == 1 && arms[0].guard.is_none();
- if let hir::ExprKind::Loop(ref block, _, _) = arms[0].body.node;
+ if let hir::ExprKind::Loop(ref block, _, _) = arms[0].body.kind;
if block.expr.is_none();
if let [ _, _, ref let_stmt, ref body ] = *block.stmts;
- if let hir::StmtKind::Decl(ref decl, _) = let_stmt.node;
- if let hir::DeclKind::Local(ref decl) = decl.node;
- if let hir::StmtKind::Expr(ref expr, _) = body.node;
+ if let hir::StmtKind::Local(ref local) = let_stmt.kind;
+ if let hir::StmtKind::Expr(ref expr) = body.kind;
then {
- return Some((&*decl.pat, &iterargs[0], expr));
+ return Some((&*local.pat, &iterargs[0], expr));
}
}
None
}
+/// Recover the essential nodes of a desugared while loop:
+/// `while cond { body }` becomes `(cond, body)`.
+pub fn while_loop(expr: &hir::Expr) -> Option<(&hir::Expr, &hir::Expr)> {
+ if_chain! {
+ if let hir::ExprKind::Loop(block, _, hir::LoopSource::While) = &expr.kind;
+ if let hir::Block { expr: Some(expr), .. } = &**block;
+ if let hir::ExprKind::Match(cond, arms, hir::MatchSource::WhileDesugar) = &expr.kind;
+ if let hir::ExprKind::DropTemps(cond) = &cond.kind;
+ if let [arm, ..] = &arms[..];
+ if let hir::Arm { body, .. } = arm;
+ then {
+ return Some((cond, body));
+ }
+ }
+ None
+}
+
+/// Recover the essential nodes of a desugared if block
+/// `if cond { then } else { els }` becomes `(cond, then, Some(els))`
+pub fn if_block(expr: &hir::Expr) -> Option<(&hir::Expr, &hir::Expr, Option<&hir::Expr>)> {
+ if let hir::ExprKind::Match(ref cond, ref arms, hir::MatchSource::IfDesugar { contains_else_clause }) = expr.kind {
+ let cond = if let hir::ExprKind::DropTemps(ref cond) = cond.kind {
+ cond
+ } else {
+ panic!("If block desugar must contain DropTemps");
+ };
+ let then = &arms[0].body;
+ let els = if contains_else_clause {
+ Some(&*arms[1].body)
+ } else {
+ None
+ };
+ Some((cond, then, els))
+ } else {
+ None
+ }
+}
+
/// Represent the pre-expansion arguments of a `vec!` invocation.
pub enum VecArgs<'a> {
/// `vec![elem; len]`
/// from `vec!`.
pub fn vec_macro<'e>(cx: &LateContext<'_, '_>, expr: &'e hir::Expr) -> Option<VecArgs<'e>> {
if_chain! {
- if let hir::ExprKind::Call(ref fun, ref args) = expr.node;
- if let hir::ExprKind::Path(ref path) = fun.node;
+ if let hir::ExprKind::Call(ref fun, ref args) = expr.kind;
+ if let hir::ExprKind::Path(ref qpath) = fun.kind;
if is_expn_of(fun.span, "vec").is_some();
- if let Some(fun_def_id) = opt_def_id(resolve_node(cx, path, fun.hir_id));
+ if let Some(fun_def_id) = cx.tables.qpath_res(qpath, fun.hir_id).opt_def_id();
then {
- return if match_def_path(cx.tcx, fun_def_id, &paths::VEC_FROM_ELEM) && args.len() == 2 {
+ 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.tcx, 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(ref boxed) = args[0].node;
- if let hir::ExprKind::Array(ref args) = boxed.node;
+ if let hir::ExprKind::Box(ref boxed) = args[0].kind;
+ if let hir::ExprKind::Array(ref args) = boxed.kind;
then {
return Some(VecArgs::Vec(&*args));
}
projects / rust.git / blobdiff