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syntax: Parse import prefixes as paths
1 parent 6fa61b8 commit e7bc939

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9 files changed

+224
-134
lines changed

9 files changed

+224
-134
lines changed

‎src/librustc_resolve/build_reduced_graph.rs‎

Lines changed: 35 additions & 19 deletions
Original file line numberDiff line numberDiff line change
@@ -28,9 +28,9 @@ use rustc::hir::def::*;
2828
use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId};
2929
use rustc::ty::{self, VariantKind};
3030

31-
use syntax::ast::Name;
31+
use syntax::ast::{Name, NodeId};
3232
use syntax::attr::AttrMetaMethods;
33-
use syntax::parse::token::{special_idents, SELF_KEYWORD_NAME, SUPER_KEYWORD_NAME};
33+
use syntax::parse::token::keywords;
3434
use syntax::codemap::{Span, DUMMY_SP};
3535

3636
use rustc::hir;
@@ -100,6 +100,37 @@ impl<'b, 'tcx:'b> Resolver<'b, 'tcx> {
100100
block.stmts.iter().any(is_item)
101101
}
102102

103+
fn sanity_check_import(&self, view_path: &hir::ViewPath, id: NodeId) {
104+
let path = match view_path.node {
105+
ViewPathSimple(_, ref path) |
106+
ViewPathGlob (ref path) |
107+
ViewPathList(ref path, _) => path
108+
};
109+
110+
// Check for type parameters
111+
let found_param = path.segments.iter().any(|segment| {
112+
!segment.parameters.types().is_empty() ||
113+
!segment.parameters.lifetimes().is_empty() ||
114+
!segment.parameters.bindings().is_empty()
115+
});
116+
if found_param {
117+
self.session.span_err(path.span,
118+
"type or lifetime parameter is found in import path");
119+
}
120+
121+
// Checking for special identifiers in path
122+
// prevent `self` or `super` at beginning of global path
123+
if path.global && path.segments.len() > 0 {
124+
let first = path.segments[0].identifier.name;
125+
if first == keywords::Super.to_name() || first == keywords::SelfValue.to_name() {
126+
self.session.add_lint(
127+
lint::builtin::SUPER_OR_SELF_IN_GLOBAL_PATH, id, path.span,
128+
format!("expected identifier, found keyword `{}`", first)
129+
);
130+
}
131+
}
132+
}
133+
103134
/// Constructs the reduced graph for one item.
104135
fn build_reduced_graph_for_item(&mut self, item: &Item, parent_ref: &mut Module<'b>) {
105136
let parent = *parent_ref;
@@ -117,10 +148,8 @@ impl<'b, 'tcx:'b> Resolver<'b, 'tcx> {
117148
// Extract and intern the module part of the path. For
118149
// globs and lists, the path is found directly in the AST;
119150
// for simple paths we have to munge the path a little.
120-
let is_global;
121151
let module_path: Vec<Name> = match view_path.node {
122152
ViewPathSimple(_, ref full_path) => {
123-
is_global = full_path.global;
124153
full_path.segments
125154
.split_last()
126155
.unwrap()
@@ -132,30 +161,17 @@ impl<'b, 'tcx:'b> Resolver<'b, 'tcx> {
132161

133162
ViewPathGlob(ref module_ident_path) |
134163
ViewPathList(ref module_ident_path, _) => {
135-
is_global = module_ident_path.global;
136164
module_ident_path.segments
137165
.iter()
138166
.map(|seg| seg.identifier.name)
139167
.collect()
140168
}
141169
};
142170

143-
// Checking for special identifiers in path
144-
// prevent `self` or `super` at beginning of global path
145-
if is_global && (module_path.first() == Some(&SELF_KEYWORD_NAME) ||
146-
module_path.first() == Some(&SUPER_KEYWORD_NAME)) {
147-
self.session.add_lint(
148-
lint::builtin::SUPER_OR_SELF_IN_GLOBAL_PATH,
149-
item.id,
150-
item.span,
151-
format!("expected identifier, found keyword `{}`",
152-
module_path.first().unwrap().as_str()));
153-
}
171+
self.sanity_check_import(view_path, item.id);
154172

155173
// Build up the import directives.
156-
let is_prelude = item.attrs.iter().any(|attr| {
157-
attr.name() == special_idents::prelude_import.name.as_str()
158-
});
174+
let is_prelude = item.attrs.iter().any(|attr| attr.name() == "prelude_import");
159175

160176
match view_path.node {
161177
ViewPathSimple(binding, ref full_path) => {

‎src/libsyntax/parse/parser.rs‎

Lines changed: 63 additions & 111 deletions
Original file line numberDiff line numberDiff line change
@@ -81,6 +81,8 @@ type ItemInfo = (Ident, ItemKind, Option<Vec<Attribute> >);
8181
pub enum PathParsingMode {
8282
/// A path with no type parameters; e.g. `foo::bar::Baz`
8383
NoTypesAllowed,
84+
/// Same as `NoTypesAllowed`, but may end with `::{` or `::*`, which are left unparsed
85+
ImportPrefix,
8486
/// A path with a lifetime and type parameters, with no double colons
8587
/// before the type parameters; e.g. `foo::bar<'a>::Baz<T>`
8688
LifetimeAndTypesWithoutColons,
@@ -589,20 +591,6 @@ impl<'a> Parser<'a> {
589591
}
590592
}
591593

592-
pub fn parse_path_list_item(&mut self) -> PResult<'a, ast::PathListItem> {
593-
let lo = self.span.lo;
594-
let node = if self.eat_keyword(keywords::SelfValue) {
595-
let rename = self.parse_rename()?;
596-
ast::PathListItemKind::Mod { id: ast::DUMMY_NODE_ID, rename: rename }
597-
} else {
598-
let ident = self.parse_ident()?;
599-
let rename = self.parse_rename()?;
600-
ast::PathListItemKind::Ident { name: ident, rename: rename, id: ast::DUMMY_NODE_ID }
601-
};
602-
let hi = self.last_span.hi;
603-
Ok(spanned(lo, hi, node))
604-
}
605-
606594
/// Check if the next token is `tok`, and return `true` if so.
607595
///
608596
/// This method will automatically add `tok` to `expected_tokens` if `tok` is not
@@ -1761,8 +1749,8 @@ impl<'a> Parser<'a> {
17611749
LifetimeAndTypesWithColons => {
17621750
self.parse_path_segments_with_colons()?
17631751
}
1764-
NoTypesAllowed => {
1765-
self.parse_path_segments_without_types()?
1752+
NoTypesAllowed | ImportPrefix => {
1753+
self.parse_path_segments_without_types(mode == ImportPrefix)?
17661754
}
17671755
};
17681756
path.segments.extend(segments);
@@ -1799,8 +1787,8 @@ impl<'a> Parser<'a> {
17991787
LifetimeAndTypesWithColons => {
18001788
self.parse_path_segments_with_colons()?
18011789
}
1802-
NoTypesAllowed => {
1803-
self.parse_path_segments_without_types()?
1790+
NoTypesAllowed | ImportPrefix => {
1791+
self.parse_path_segments_without_types(mode == ImportPrefix)?
18041792
}
18051793
};
18061794

@@ -1918,7 +1906,8 @@ impl<'a> Parser<'a> {
19181906

19191907
/// Examples:
19201908
/// - `a::b::c`
1921-
pub fn parse_path_segments_without_types(&mut self) -> PResult<'a, Vec<ast::PathSegment>> {
1909+
pub fn parse_path_segments_without_types(&mut self, import_prefix: bool)
1910+
-> PResult<'a, Vec<ast::PathSegment>> {
19221911
let mut segments = Vec::new();
19231912
loop {
19241913
// First, parse an identifier.
@@ -1930,9 +1919,11 @@ impl<'a> Parser<'a> {
19301919
parameters: ast::PathParameters::none()
19311920
});
19321921

1933-
// If we do not see a `::`, stop.
1934-
if !self.eat(&token::ModSep) {
1922+
// If we do not see a `::` or see `::{`/`::*`, stop.
1923+
if !self.check(&token::ModSep) || import_prefix && self.is_import_coupler() {
19351924
return Ok(segments);
1925+
} else {
1926+
self.bump();
19361927
}
19371928
}
19381929
}
@@ -6119,106 +6110,67 @@ impl<'a> Parser<'a> {
61196110
self.parse_item_(attrs, true, false)
61206111
}
61216112

6113+
fn parse_path_list_items(&mut self) -> PResult<'a, Vec<ast::PathListItem>> {
6114+
self.parse_unspanned_seq(&token::OpenDelim(token::Brace),
6115+
&token::CloseDelim(token::Brace),
6116+
SeqSep::trailing_allowed(token::Comma), |this| {
6117+
let lo = this.span.lo;
6118+
let node = if this.eat_keyword(keywords::SelfValue) {
6119+
let rename = this.parse_rename()?;
6120+
ast::PathListItemKind::Mod { id: ast::DUMMY_NODE_ID, rename: rename }
6121+
} else {
6122+
let ident = this.parse_ident()?;
6123+
let rename = this.parse_rename()?;
6124+
ast::PathListItemKind::Ident { name: ident, rename: rename, id: ast::DUMMY_NODE_ID }
6125+
};
6126+
let hi = this.last_span.hi;
6127+
Ok(spanned(lo, hi, node))
6128+
})
6129+
}
6130+
6131+
/// `::{` or `::*`
6132+
fn is_import_coupler(&mut self) -> bool {
6133+
self.check(&token::ModSep) &&
6134+
self.look_ahead(1, |t| *t == token::OpenDelim(token::Brace) ||
6135+
*t == token::BinOp(token::Star))
6136+
}
61226137

6123-
/// Matches view_path : MOD? non_global_path as IDENT
6124-
/// | MOD? non_global_path MOD_SEP LBRACE RBRACE
6125-
/// | MOD? non_global_path MOD_SEP LBRACE ident_seq RBRACE
6126-
/// | MOD? non_global_path MOD_SEP STAR
6127-
/// | MOD? non_global_path
6138+
/// Matches ViewPath:
6139+
/// MOD_SEP? non_global_path
6140+
/// MOD_SEP? non_global_path as IDENT
6141+
/// MOD_SEP? non_global_path MOD_SEP STAR
6142+
/// MOD_SEP? non_global_path MOD_SEP LBRACE item_seq RBRACE
6143+
/// MOD_SEP? LBRACE item_seq RBRACE
61286144
fn parse_view_path(&mut self) -> PResult<'a, P<ViewPath>> {
61296145
let lo = self.span.lo;
6130-
6131-
// Allow a leading :: because the paths are absolute either way.
6132-
// This occurs with "use $crate::..." in macros.
6133-
let is_global = self.eat(&token::ModSep);
6134-
6135-
if self.check(&token::OpenDelim(token::Brace)) {
6136-
// use {foo,bar}
6137-
let idents = self.parse_unspanned_seq(
6138-
&token::OpenDelim(token::Brace),
6139-
&token::CloseDelim(token::Brace),
6140-
SeqSep::trailing_allowed(token::Comma),
6141-
|p| p.parse_path_list_item())?;
6142-
let path = ast::Path {
6146+
if self.check(&token::OpenDelim(token::Brace)) || self.is_import_coupler() {
6147+
// `{foo, bar}` or `::{foo, bar}`
6148+
let prefix = ast::Path {
6149+
global: self.eat(&token::ModSep),
6150+
segments: Vec::new(),
61436151
span: mk_sp(lo, self.span.hi),
6144-
global: is_global,
6145-
segments: Vec::new()
61466152
};
6147-
return Ok(P(spanned(lo, self.span.hi, ViewPathList(path, idents))));
6148-
}
6149-
6150-
let first_ident = self.parse_ident()?;
6151-
let mut path = vec!(first_ident);
6152-
if let token::ModSep = self.token {
6153-
// foo::bar or foo::{a,b,c} or foo::*
6154-
while self.check(&token::ModSep) {
6153+
let items = self.parse_path_list_items()?;
6154+
Ok(P(spanned(lo, self.span.hi, ViewPathList(prefix, items))))
6155+
} else {
6156+
let prefix = self.parse_path(ImportPrefix)?;
6157+
if self.is_import_coupler() {
6158+
// `foo::bar::{a, b}` or `foo::bar::*`
61556159
self.bump();
6156-
6157-
match self.token {
6158-
token::Ident(..) => {
6159-
let ident = self.parse_ident()?;
6160-
path.push(ident);
6161-
}
6162-
6163-
// foo::bar::{a,b,c}
6164-
token::OpenDelim(token::Brace) => {
6165-
let idents = self.parse_unspanned_seq(
6166-
&token::OpenDelim(token::Brace),
6167-
&token::CloseDelim(token::Brace),
6168-
SeqSep::trailing_allowed(token::Comma),
6169-
|p| p.parse_path_list_item()
6170-
)?;
6171-
let path = ast::Path {
6172-
span: mk_sp(lo, self.span.hi),
6173-
global: is_global,
6174-
segments: path.into_iter().map(|identifier| {
6175-
ast::PathSegment {
6176-
identifier: identifier,
6177-
parameters: ast::PathParameters::none(),
6178-
}
6179-
}).collect()
6180-
};
6181-
return Ok(P(spanned(lo, self.span.hi, ViewPathList(path, idents))));
6182-
}
6183-
6184-
// foo::bar::*
6185-
token::BinOp(token::Star) => {
6160+
if self.check(&token::BinOp(token::Star)) {
61866161
self.bump();
6187-
let path = ast::Path {
6188-
span: mk_sp(lo, self.span.hi),
6189-
global: is_global,
6190-
segments: path.into_iter().map(|identifier| {
6191-
ast::PathSegment {
6192-
identifier: identifier,
6193-
parameters: ast::PathParameters::none(),
6194-
}
6195-
}).collect()
6196-
};
6197-
return Ok(P(spanned(lo, self.span.hi, ViewPathGlob(path))));
6198-
}
6199-
6200-
// fall-through for case foo::bar::;
6201-
token::Semi => {
6202-
self.span_err(self.span, "expected identifier or `{` or `*`, found `;`");
6203-
}
6204-
6205-
_ => break
6162+
Ok(P(spanned(lo, self.span.hi, ViewPathGlob(prefix))))
6163+
} else {
6164+
let items = self.parse_path_list_items()?;
6165+
Ok(P(spanned(lo, self.span.hi, ViewPathList(prefix, items))))
62066166
}
6167+
} else {
6168+
// `foo::bar` or `foo::bar as baz`
6169+
let rename = self.parse_rename()?.
6170+
unwrap_or(prefix.segments.last().unwrap().identifier);
6171+
Ok(P(spanned(lo, self.last_span.hi, ViewPathSimple(rename, prefix))))
62076172
}
62086173
}
6209-
let mut rename_to = path[path.len() - 1];
6210-
let path = ast::Path {
6211-
span: mk_sp(lo, self.last_span.hi),
6212-
global: is_global,
6213-
segments: path.into_iter().map(|identifier| {
6214-
ast::PathSegment {
6215-
identifier: identifier,
6216-
parameters: ast::PathParameters::none(),
6217-
}
6218-
}).collect()
6219-
};
6220-
rename_to = self.parse_rename()?.unwrap_or(rename_to);
6221-
Ok(P(spanned(lo, self.last_span.hi, ViewPathSimple(rename_to, path))))
62226174
}
62236175

62246176
fn parse_rename(&mut self) -> PResult<'a, Option<Ident>> {

‎src/test/compile-fail/import-prefix-macro-1.rs‎

Lines changed: 26 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,26 @@
1+
// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
mod a {
12+
pub mod b {
13+
pub mod c {
14+
pub struct S;
15+
pub struct Z;
16+
}
17+
}
18+
}
19+
20+
macro_rules! import {
21+
($p: path) => (use $p {S, Z}); //~ERROR expected one of `::`, `;`, or `as`, found `{`
22+
}
23+
24+
import! { a::b::c }
25+
26+
fn main() {}

‎src/test/compile-fail/import-prefix-macro-2.rs‎

Lines changed: 26 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,26 @@
1+
// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
mod a {
12+
pub mod b {
13+
pub mod c {
14+
pub struct S;
15+
pub struct Z;
16+
}
17+
}
18+
}
19+
20+
macro_rules! import {
21+
($p: path) => (use ::$p {S, Z}); //~ERROR expected identifier, found `a::b::c`
22+
}
23+
24+
import! { a::b::c }
25+
26+
fn main() {}

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