d75b0ae7ce
This test currently fails (as expected).
--- stderr -------------------------------
Pretty-printer lost necessary parentheses
BEFORE: (#[attr] loop {}).field
AFTER: #[attr] loop {}.field
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84 lines
2.6 KiB
Rust
84 lines
2.6 KiB
Rust
#![feature(rustc_private)]
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extern crate rustc_ast;
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extern crate rustc_driver;
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extern crate rustc_errors;
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extern crate rustc_parse;
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extern crate rustc_session;
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extern crate rustc_span;
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use rustc_ast::ast::{AttrKind, Attribute, DUMMY_NODE_ID, Expr};
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use rustc_ast::mut_visit::{self, MutVisitor};
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use rustc_ast::node_id::NodeId;
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use rustc_ast::ptr::P;
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use rustc_ast::token::{self, Token};
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use rustc_ast::tokenstream::{AttrTokenStream, AttrTokenTree, LazyAttrTokenStream};
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use rustc_errors::Diag;
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use rustc_parse::parser::Recovery;
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use rustc_session::parse::ParseSess;
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use rustc_span::{AttrId, DUMMY_SP, FileName, Span};
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use std::sync::Arc;
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pub fn parse_expr(psess: &ParseSess, source_code: &str) -> Option<P<Expr>> {
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let parser = rustc_parse::unwrap_or_emit_fatal(rustc_parse::new_parser_from_source_str(
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psess,
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FileName::anon_source_code(source_code),
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source_code.to_owned(),
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));
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let mut parser = parser.recovery(Recovery::Forbidden);
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let mut expr = parser.parse_expr().map_err(Diag::cancel).ok()?;
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if parser.token != token::Eof {
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return None;
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}
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Normalize.visit_expr(&mut expr);
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Some(expr)
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}
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// Erase Span information that could distinguish between identical expressions
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// parsed from different source strings.
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struct Normalize;
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impl MutVisitor for Normalize {
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fn visit_id(&mut self, id: &mut NodeId) {
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*id = DUMMY_NODE_ID;
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}
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fn visit_span(&mut self, span: &mut Span) {
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*span = DUMMY_SP;
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}
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fn visit_attribute(&mut self, attr: &mut Attribute) {
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attr.id = AttrId::from_u32(0);
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if let AttrKind::Normal(normal_attr) = &mut attr.kind {
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if let Some(tokens) = &mut normal_attr.tokens {
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let mut stream = tokens.to_attr_token_stream();
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normalize_attr_token_stream(&mut stream);
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*tokens = LazyAttrTokenStream::new_direct(stream);
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}
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}
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mut_visit::walk_attribute(self, attr);
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}
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}
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fn normalize_attr_token_stream(stream: &mut AttrTokenStream) {
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Arc::make_mut(&mut stream.0)
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.iter_mut()
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.for_each(normalize_attr_token_tree);
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}
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fn normalize_attr_token_tree(token: &mut AttrTokenTree) {
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match token {
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AttrTokenTree::Token(token, _spacing) => {
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Normalize.visit_span(&mut token.span);
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}
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AttrTokenTree::Delimited(dspan, _spacing, _delim, stream) => {
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normalize_attr_token_stream(stream);
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Normalize.visit_span(&mut dspan.open);
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Normalize.visit_span(&mut dspan.close);
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}
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AttrTokenTree::AttrsTarget(_) => unimplemented!("AttrTokenTree::AttrsTarget"),
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}
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}
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