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Pretty-print $crate as crate/::my_crate in tokens

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...but only if those tokens are printed from inside of AST pretty-printing.
This commit is contained in:
Vadim Petrochenkov 2019-07-04 02:37:34 +03:00
parent 7aaf0de700
commit 4344a90308
3 changed files with 70 additions and 55 deletions
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109
src/libsyntax/print/pprust.rs
View file

@ -18,7 +18,7 @@ use crate::tokenstream::{self, TokenStream, TokenTree};
use rustc_target::spec::abi::{self, Abi};
use syntax_pos::{self, BytePos};
use syntax_pos::{DUMMY_SP, FileName};
use syntax_pos::{DUMMY_SP, FileName, Span};
use std::borrow::Cow;
use std::io::Read;
@ -181,7 +181,46 @@ pub fn literal_to_string(lit: token::Lit) -> String {
out
}
fn ident_to_string(ident: ast::Ident, is_raw: bool) -> String {
ident_to_string_ext(ident.name, is_raw, Some(ident.span))
}
// AST pretty-printer is used as a fallback for turning AST structures into token streams for
// proc macros. Additionally, proc macros may stringify their input and expect it survive the
// stringification (especially true for proc macro derives written between Rust 1.15 and 1.30).
// So we need to somehow pretty-print `$crate` in a way preserving at least some of its
// hygiene data, most importantly name of the crate it refers to.
// As a result we print `$crate` as `crate` if it refers to the local crate
// and as `::other_crate_name` if it refers to some other crate.
// Note, that this is only done if the ident token is printed from inside of AST pretty-pringing,
// but not otherwise. Pretty-printing is the only way for proc macros to discover token contents,
// so we should not perform this lossy conversion if the top level call to the pretty-printer was
// done for a token stream or a single token.
fn ident_to_string_ext(
name: ast::Name, is_raw: bool, convert_dollar_crate: Option<Span>
) -> String {
if is_raw {
format!("r#{}", name)
} else {
if name == kw::DollarCrate {
if let Some(span) = convert_dollar_crate {
let converted = span.ctxt().dollar_crate_name();
return if converted.is_path_segment_keyword() {
converted.to_string()
} else {
format!("::{}", converted)
}
}
}
name.to_string()
}
}
pub fn token_kind_to_string(tok: &TokenKind) -> String {
token_kind_to_string_ext(tok, None)
}
fn token_kind_to_string_ext(tok: &TokenKind, convert_dollar_crate: Option<Span>) -> String {
match *tok {
token::Eq => "=".to_string(),
token::Lt => "<".to_string(),
@ -227,8 +266,7 @@ pub fn token_kind_to_string(tok: &TokenKind) -> String {
token::Literal(lit) => literal_to_string(lit),
/* Name components */
token::Ident(s, false) => s.to_string(),
token::Ident(s, true) => format!("r#{}", s),
token::Ident(s, is_raw) => ident_to_string_ext(s, is_raw, convert_dollar_crate),
token::Lifetime(s) => s.to_string(),
/* Other */
@ -243,7 +281,12 @@ pub fn token_kind_to_string(tok: &TokenKind) -> String {
}
pub fn token_to_string(token: &Token) -> String {
token_kind_to_string(&token.kind)
token_to_string_ext(token, false)
}
fn token_to_string_ext(token: &Token, convert_dollar_crate: bool) -> String {
let convert_dollar_crate = if convert_dollar_crate { Some(token.span) } else { None };
token_kind_to_string_ext(&token.kind, convert_dollar_crate)
}
crate fn nonterminal_to_string(nt: &Nonterminal) -> String {
@ -256,9 +299,8 @@ crate fn nonterminal_to_string(nt: &Nonterminal) -> String {
token::NtBlock(ref e) => block_to_string(e),
token::NtStmt(ref e) => stmt_to_string(e),
token::NtPat(ref e) => pat_to_string(e),
token::NtIdent(e, false) => ident_to_string(e),
token::NtIdent(e, true) => format!("r#{}", ident_to_string(e)),
token::NtLifetime(e) => ident_to_string(e),
token::NtIdent(e, is_raw) => ident_to_string(e, is_raw),
token::NtLifetime(e) => e.to_string(),
token::NtLiteral(ref e) => expr_to_string(e),
token::NtTT(ref tree) => tt_to_string(tree.clone()),
token::NtImplItem(ref e) => impl_item_to_string(e),
@ -293,15 +335,15 @@ pub fn lifetime_to_string(lt: &ast::Lifetime) -> String {
}
pub fn tt_to_string(tt: tokenstream::TokenTree) -> String {
to_string(|s| s.print_tt(tt))
to_string(|s| s.print_tt(tt, false))
}
pub fn tts_to_string(tts: &[tokenstream::TokenTree]) -> String {
to_string(|s| s.print_tts(tts.iter().cloned().collect()))
tokens_to_string(tts.iter().cloned().collect())
}
pub fn tokens_to_string(tokens: TokenStream) -> String {
to_string(|s| s.print_tts(tokens))
to_string(|s| s.print_tts_ext(tokens, false))
}
pub fn stmt_to_string(stmt: &ast::Stmt) -> String {
@ -344,10 +386,6 @@ pub fn path_segment_to_string(p: &ast::PathSegment) -> String {
to_string(|s| s.print_path_segment(p, false))
}
pub fn ident_to_string(id: ast::Ident) -> String {
to_string(|s| s.print_ident(id))
}
pub fn vis_to_string(v: &ast::Visibility) -> String {
to_string(|s| s.print_visibility(v))
}
@ -629,11 +667,7 @@ pub trait PrintState<'a> {
self.writer().word("::");
}
if segment.ident.name != kw::PathRoot {
if segment.ident.name == kw::DollarCrate {
self.print_dollar_crate(segment.ident);
} else {
self.writer().word(segment.ident.as_str().to_string());
}
self.writer().word(ident_to_string(segment.ident, segment.ident.is_raw_guess()));
}
}
}
@ -707,10 +741,10 @@ pub trait PrintState<'a> {
/// appropriate macro, transcribe back into the grammar we just parsed from,
/// and then pretty-print the resulting AST nodes (so, e.g., we print
/// expression arguments as expressions). It can be done! I think.
fn print_tt(&mut self, tt: tokenstream::TokenTree) {
fn print_tt(&mut self, tt: tokenstream::TokenTree, convert_dollar_crate: bool) {
match tt {
TokenTree::Token(ref token) => {
self.writer().word(token_to_string(&token));
self.writer().word(token_to_string_ext(&token, convert_dollar_crate));
match token.kind {
token::DocComment(..) => {
self.writer().hardbreak()
@ -729,12 +763,16 @@ pub trait PrintState<'a> {
}
fn print_tts(&mut self, tts: tokenstream::TokenStream) {
self.print_tts_ext(tts, true)
}
fn print_tts_ext(&mut self, tts: tokenstream::TokenStream, convert_dollar_crate: bool) {
self.ibox(0);
for (i, tt) in tts.into_trees().enumerate() {
if i != 0 {
self.writer().space();
}
self.print_tt(tt);
self.print_tt(tt, convert_dollar_crate);
}
self.end();
}
@ -744,21 +782,6 @@ pub trait PrintState<'a> {
}
fn nbsp(&mut self) { self.writer().word(" ") }
// AST pretty-printer is used as a fallback for turning AST structures into token streams for
// proc macros. Additionally, proc macros may stringify their input and expect it survive the
// stringification (especially true for proc macro derives written between Rust 1.15 and 1.30).
// So we need to somehow pretty-print `$crate` in paths in a way preserving at least some of
// its hygiene data, most importantly name of the crate it refers to.
// As a result we print `$crate` as `crate` if it refers to the local crate
// and as `::other_crate_name` if it refers to some other crate.
fn print_dollar_crate(&mut self, ident: ast::Ident) {
let name = ident.span.ctxt().dollar_crate_name();
if !ast::Ident::with_empty_ctxt(name).is_path_segment_keyword() {
self.writer().word("::");
}
self.writer().word(name.as_str().to_string())
}
}
impl<'a> PrintState<'a> for State<'a> {
@ -2287,11 +2310,7 @@ impl<'a> State<'a> {
}
crate fn print_ident(&mut self, ident: ast::Ident) {
if ident.is_raw_guess() {
self.s.word(format!("r#{}", ident));
} else {
self.s.word(ident.as_str().to_string());
}
self.s.word(ident_to_string(ident, ident.is_raw_guess()));
self.ann.post(self, AnnNode::Ident(&ident))
}
@ -2322,11 +2341,7 @@ impl<'a> State<'a> {
segment: &ast::PathSegment,
colons_before_params: bool) {
if segment.ident.name != kw::PathRoot {
if segment.ident.name == kw::DollarCrate {
self.print_dollar_crate(segment.ident);
} else {
self.print_ident(segment.ident);
}
self.print_ident(segment.ident);
if let Some(ref args) = segment.args {
self.print_generic_args(args, colons_before_params);
}

4
src/test/ui/proc-macro/dollar-crate-issue-57089.stdout
View file

@ -1,4 +1,4 @@
PRINT-BANG INPUT (DISPLAY): struct M ( $crate :: S ) ;
PRINT-BANG INPUT (DISPLAY): struct M ( crate :: S ) ;
PRINT-BANG INPUT (DEBUG): TokenStream [
Ident {
ident: "struct",
@ -39,7 +39,7 @@ PRINT-BANG INPUT (DEBUG): TokenStream [
},
]
PRINT-ATTR INPUT (DISPLAY): struct A(crate::S);
PRINT-ATTR RE-COLLECTED (DISPLAY): struct A ( $crate :: S ) ;
PRINT-ATTR RE-COLLECTED (DISPLAY): struct A ( crate :: S ) ;
PRINT-ATTR INPUT (DEBUG): TokenStream [
Ident {
ident: "struct",

12
src/test/ui/proc-macro/dollar-crate.stdout
View file

@ -1,4 +1,4 @@
PRINT-BANG INPUT (DISPLAY): struct M ( $crate :: S ) ;
PRINT-BANG INPUT (DISPLAY): struct M ( crate :: S ) ;
PRINT-BANG INPUT (DEBUG): TokenStream [
Ident {
ident: "struct",
@ -39,7 +39,7 @@ PRINT-BANG INPUT (DEBUG): TokenStream [
},
]
PRINT-ATTR INPUT (DISPLAY): struct A(crate::S);
PRINT-ATTR RE-COLLECTED (DISPLAY): struct A ( $crate :: S ) ;
PRINT-ATTR RE-COLLECTED (DISPLAY): struct A ( crate :: S ) ;
PRINT-ATTR INPUT (DEBUG): TokenStream [
Ident {
ident: "struct",
@ -80,7 +80,7 @@ PRINT-ATTR INPUT (DEBUG): TokenStream [
},
]
PRINT-DERIVE INPUT (DISPLAY): struct D(crate::S);
PRINT-DERIVE RE-COLLECTED (DISPLAY): struct D ( $crate :: S ) ;
PRINT-DERIVE RE-COLLECTED (DISPLAY): struct D ( crate :: S ) ;
PRINT-DERIVE INPUT (DEBUG): TokenStream [
Ident {
ident: "struct",
@ -120,7 +120,7 @@ PRINT-DERIVE INPUT (DEBUG): TokenStream [
span: #2 bytes(LO..HI),
},
]
PRINT-BANG INPUT (DISPLAY): struct M ( $crate :: S ) ;
PRINT-BANG INPUT (DISPLAY): struct M ( ::dollar_crate_external :: S ) ;
PRINT-BANG INPUT (DEBUG): TokenStream [
Ident {
ident: "struct",
@ -161,7 +161,7 @@ PRINT-BANG INPUT (DEBUG): TokenStream [
},
]
PRINT-ATTR INPUT (DISPLAY): struct A(::dollar_crate_external::S);
PRINT-ATTR RE-COLLECTED (DISPLAY): struct A ( $crate :: S ) ;
PRINT-ATTR RE-COLLECTED (DISPLAY): struct A ( ::dollar_crate_external :: S ) ;
PRINT-ATTR INPUT (DEBUG): TokenStream [
Ident {
ident: "struct",
@ -202,7 +202,7 @@ PRINT-ATTR INPUT (DEBUG): TokenStream [
},
]
PRINT-DERIVE INPUT (DISPLAY): struct D(::dollar_crate_external::S);
PRINT-DERIVE RE-COLLECTED (DISPLAY): struct D ( $crate :: S ) ;
PRINT-DERIVE RE-COLLECTED (DISPLAY): struct D ( ::dollar_crate_external :: S ) ;
PRINT-DERIVE INPUT (DEBUG): TokenStream [
Ident {
ident: "struct",