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Merge #4227

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4227: Report invalid, nested, multi-segment crate-paths r=matklad a=djrenren

There was a bug in the previous path-validating code that didn't detect multi-segment paths that started with `crate`.

```rust
// Successfully reported
use foo::{crate};

// BUG: was not being reported
use foo::{crate::bar};
```

This was due to my confusion about path-associativity. That is, the path with no qualifier is the innermost path, not the outermost. I've updated the code with a lot of comments to explain what's going on. 

This bug was discovered when I found an erroneous `ok` test which I reported here: 
https://github.com/rust-analyzer/rust-analyzer/issues/4226

This test now fails and has been modified, hopefully in the spirit of the original test, to be correct.  Sorry about submitting the bug in the first place!

Co-authored-by: John Renner <john@jrenner.net>
This commit is contained in:
bors[bot] 2020-04-30 18:37:35 +00:00 committed by GitHub
commit 745bd45ddb
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GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 116 additions and 81 deletions
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2
crates/ra_parser/src/grammar/items/use_item.rs
View File

@ -47,7 +47,7 @@ fn use_tree(p: &mut Parser, top_level: bool) {
// use {crate::path::from::root, or::path::from::crate_name}; // Rust 2018 (with a crate named `or`)
// use {path::from::root}; // Rust 2015
// use ::{some::arbritrary::path}; // Rust 2015
// use ::{{{crate::export}}}; // Nonsensical but perfectly legal nestnig
// use ::{{{root::export}}}; // Nonsensical but perfectly legal nesting
T!['{'] => {
use_tree_list(p);
}

29
crates/ra_syntax/src/validation.rs
View File

@ -236,21 +236,40 @@ fn validate_crate_keyword_in_path_segment(
};
// Disallow both ::crate and foo::crate
let path = segment.parent_path();
let mut path = segment.parent_path();
if segment.coloncolon_token().is_some() || path.qualifier().is_some() {
errors.push(SyntaxError::new(ERR_MSG, crate_token.text_range()));
return;
}
// We now know that the path variable describes a complete path.
// For expressions and types, validation is complete, but we still have
// to handle UseItems like this:
// use foo:{crate};
// so we crawl upwards looking for any preceding paths on `UseTree`s
// to handle invalid UseItems like this:
//
// use foo:{crate::bar::baz};
//
// To handle this we must inspect the parent `UseItem`s and `UseTree`s
// but right now we're looking deep inside the nested `Path` nodes because
// `Path`s are left-associative:
//
// ((crate)::bar)::baz)
// ^ current value of path
//
// So we need to climb to the top
while let Some(parent) = path.parent_path() {
path = parent;
}
// Now that we've found the whole path we need to see if there's a prefix
// somewhere in the UseTree hierarchy. This check is arbitrarily deep
// because rust allows arbitrary nesting like so:
//
// use {foo::{{{{crate::bar::baz}}}}};
for node in path.syntax().ancestors().skip(1) {
match_ast! {
match node {
ast::UseTree(it) => if let Some(tree_path) = it.path() {
// Even a top-level path exists within a `UseTree` so we must explicitly
// allow our path but disallow anything else
if tree_path != path {
errors.push(SyntaxError::new(ERR_MSG, crate_token.text_range()));
}

113
crates/ra_syntax/test_data/parser/err/0040_illegal_crate_kw_location.rast
View File

@ -1,4 +1,4 @@
SOURCE_FILE@0..83
SOURCE_FILE@0..98
USE_ITEM@0..12
USE_KW@0..3 "use"
WHITESPACE@3..4 " "
@ -9,11 +9,11 @@ SOURCE_FILE@0..83
CRATE_KW@6..11 "crate"
SEMICOLON@11..12 ";"
WHITESPACE@12..13 "\n"
USE_ITEM@13..39
USE_ITEM@13..54
USE_KW@13..16 "use"
WHITESPACE@16..17 " "
USE_TREE@17..38
USE_TREE_LIST@17..38
USE_TREE@17..53
USE_TREE_LIST@17..53
L_CURLY@17..18 "{"
USE_TREE@18..23
PATH@18..23
@ -21,56 +21,71 @@ SOURCE_FILE@0..83
CRATE_KW@18..23 "crate"
COMMA@23..24 ","
WHITESPACE@24..25 " "
USE_TREE@25..37
USE_TREE@25..52
PATH@25..28
PATH_SEGMENT@25..28
NAME_REF@25..28
IDENT@25..28 "foo"
COLON2@28..30 "::"
USE_TREE_LIST@30..37
USE_TREE_LIST@30..52
L_CURLY@30..31 "{"
USE_TREE@31..36
PATH@31..36
PATH_SEGMENT@31..36
CRATE_KW@31..36 "crate"
R_CURLY@36..37 "}"
R_CURLY@37..38 "}"
SEMICOLON@38..39 ";"
WHITESPACE@39..40 "\n"
USE_ITEM@40..57
USE_KW@40..43 "use"
WHITESPACE@43..44 " "
USE_TREE@44..56
PATH@44..56
PATH@44..49
PATH_SEGMENT@44..49
NAME_REF@44..49
IDENT@44..49 "hello"
COLON2@49..51 "::"
PATH_SEGMENT@51..56
CRATE_KW@51..56 "crate"
SEMICOLON@56..57 ";"
WHITESPACE@57..58 "\n"
USE_ITEM@58..82
USE_KW@58..61 "use"
WHITESPACE@61..62 " "
USE_TREE@62..81
PATH@62..81
PATH@62..74
PATH@62..67
PATH_SEGMENT@62..67
NAME_REF@62..67
IDENT@62..67 "hello"
COLON2@67..69 "::"
PATH_SEGMENT@69..74
CRATE_KW@69..74 "crate"
COLON2@74..76 "::"
PATH_SEGMENT@76..81
NAME_REF@76..81
IDENT@76..81 "there"
SEMICOLON@81..82 ";"
WHITESPACE@82..83 "\n"
USE_TREE@31..51
PATH@31..51
PATH@31..46
PATH@31..41
PATH@31..36
PATH_SEGMENT@31..36
CRATE_KW@31..36 "crate"
COLON2@36..38 "::"
PATH_SEGMENT@38..41
NAME_REF@38..41
IDENT@38..41 "foo"
COLON2@41..43 "::"
PATH_SEGMENT@43..46
NAME_REF@43..46
IDENT@43..46 "bar"
COLON2@46..48 "::"
PATH_SEGMENT@48..51
NAME_REF@48..51
IDENT@48..51 "baz"
R_CURLY@51..52 "}"
R_CURLY@52..53 "}"
SEMICOLON@53..54 ";"
WHITESPACE@54..55 "\n"
USE_ITEM@55..72
USE_KW@55..58 "use"
WHITESPACE@58..59 " "
USE_TREE@59..71
PATH@59..71
PATH@59..64
PATH_SEGMENT@59..64
NAME_REF@59..64
IDENT@59..64 "hello"
COLON2@64..66 "::"
PATH_SEGMENT@66..71
CRATE_KW@66..71 "crate"
SEMICOLON@71..72 ";"
WHITESPACE@72..73 "\n"
USE_ITEM@73..97
USE_KW@73..76 "use"
WHITESPACE@76..77 " "
USE_TREE@77..96
PATH@77..96
PATH@77..89
PATH@77..82
PATH_SEGMENT@77..82
NAME_REF@77..82
IDENT@77..82 "hello"
COLON2@82..84 "::"
PATH_SEGMENT@84..89
CRATE_KW@84..89 "crate"
COLON2@89..91 "::"
PATH_SEGMENT@91..96
NAME_REF@91..96
IDENT@91..96 "there"
SEMICOLON@96..97 ";"
WHITESPACE@97..98 "\n"
error 6..11: The `crate` keyword is only allowed as the first segment of a path
error 31..36: The `crate` keyword is only allowed as the first segment of a path
error 51..56: The `crate` keyword is only allowed as the first segment of a path
error 69..74: The `crate` keyword is only allowed as the first segment of a path
error 66..71: The `crate` keyword is only allowed as the first segment of a path
error 84..89: The `crate` keyword is only allowed as the first segment of a path

2
crates/ra_syntax/test_data/parser/err/0040_illegal_crate_kw_location.rs
View File

@ -1,4 +1,4 @@
use ::crate;
use {crate, foo::{crate}};
use {crate, foo::{crate::foo::bar::baz}};
use hello::crate;
use hello::crate::there;

49
crates/ra_syntax/test_data/parser/inline/ok/0002_use_tree_list.rast
View File

@ -1,4 +1,4 @@
SOURCE_FILE@0..250
SOURCE_FILE@0..249
USE_ITEM@0..58
USE_KW@0..3 "use"
WHITESPACE@3..4 " "
@ -104,32 +104,33 @@ SOURCE_FILE@0..250
WHITESPACE@166..167 " "
COMMENT@167..179 "// Rust 2015"
WHITESPACE@179..180 "\n"
USE_ITEM@180..206
USE_ITEM@180..205
USE_KW@180..183 "use"
WHITESPACE@183..184 " "
USE_TREE@184..205
USE_TREE@184..204
COLON2@184..186 "::"
USE_TREE_LIST@186..205
USE_TREE_LIST@186..204
L_CURLY@186..187 "{"
USE_TREE@187..204
USE_TREE_LIST@187..204
USE_TREE@187..203
USE_TREE_LIST@187..203
L_CURLY@187..188 "{"
USE_TREE@188..203
USE_TREE_LIST@188..203
USE_TREE@188..202
USE_TREE_LIST@188..202
L_CURLY@188..189 "{"
USE_TREE@189..202
PATH@189..202
PATH@189..194
PATH_SEGMENT@189..194
CRATE_KW@189..194 "crate"
COLON2@194..196 "::"
PATH_SEGMENT@196..202
NAME_REF@196..202
IDENT@196..202 "export"
R_CURLY@202..203 "}"
R_CURLY@203..204 "}"
R_CURLY@204..205 "}"
SEMICOLON@205..206 ";"
WHITESPACE@206..207 " "
COMMENT@207..249 "// Nonsensical but pe ..."
WHITESPACE@249..250 "\n"
USE_TREE@189..201
PATH@189..201
PATH@189..193
PATH_SEGMENT@189..193
NAME_REF@189..193
IDENT@189..193 "root"
COLON2@193..195 "::"
PATH_SEGMENT@195..201
NAME_REF@195..201
IDENT@195..201 "export"
R_CURLY@201..202 "}"
R_CURLY@202..203 "}"
R_CURLY@203..204 "}"
SEMICOLON@204..205 ";"
WHITESPACE@205..206 " "
COMMENT@206..248 "// Nonsensical but pe ..."
WHITESPACE@248..249 "\n"

2
crates/ra_syntax/test_data/parser/inline/ok/0002_use_tree_list.rs
View File

@ -1,4 +1,4 @@
use {crate::path::from::root, or::path::from::crate_name}; // Rust 2018 (with a crate named `or`)
use {path::from::root}; // Rust 2015
use ::{some::arbritrary::path}; // Rust 2015
use ::{{{crate::export}}}; // Nonsensical but perfectly legal nestnig
use ::{{{root::export}}}; // Nonsensical but perfectly legal nesting