Skip to content

Revert "Unstable book options parser" #154488

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
rust-bors merged 1 commit into from
Mar 28, 2026
+587 −865
Merged

Revert "Unstable book options parser" #154488

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 0 additions & 2 deletions Cargo.lock
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6088,8 +6088,6 @@ name = "unstable-book-gen"
version = "0.1.0"
dependencies = [
"num-traits",
"proc-macro2",
"syn 2.0.110",
"tidy",
]

Expand Down
590 changes: 585 additions & 5 deletions compiler/rustc_session/src/options.rs
View file
Open in desktop

Large diffs are not rendered by default.

585 changes: 0 additions & 585 deletions compiler/rustc_session/src/options/unstable.rs
View file
Open in desktop

This file was deleted.

2 changes: 0 additions & 2 deletions src/tools/unstable-book-gen/Cargo.toml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,8 +6,6 @@ edition = "2021"

[dependencies]
tidy = { path = "../tidy" }
proc-macro2 = { version = "1.0", features = ["span-locations"] }
syn = { version = "2.0", features = ["full", "parsing"] }

# not actually needed but required for now to unify the feature selection of
# `num-traits` between this and `rustbook`
Expand Down
200 changes: 2 additions & 198 deletions src/tools/unstable-book-gen/src/main.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,16 +5,11 @@ use std::env;
use std::fs::{self, write};
use std::path::Path;

use proc_macro2::{Span, TokenStream, TokenTree};
use syn::parse::{Parse, ParseStream};
use syn::{Attribute, Ident, Item, LitStr, Token, parenthesized};
use tidy::diagnostics::RunningCheck;
use tidy::features::{
Feature, Features, Status, collect_env_vars, collect_lang_features, collect_lib_features,
};
use tidy::features::{Features, collect_env_vars, collect_lang_features, collect_lib_features};
use tidy::t;
use tidy::unstable_book::{
COMPILER_FLAGS_DIR, ENV_VARS_DIR, LANG_FEATURES_DIR, LIB_FEATURES_DIR, PATH_STR,
ENV_VARS_DIR, LANG_FEATURES_DIR, LIB_FEATURES_DIR, PATH_STR,
collect_unstable_book_section_file_names, collect_unstable_feature_names,
};

Expand Down Expand Up @@ -118,188 +113,6 @@ fn copy_recursive(from: &Path, to: &Path) {
}
}

fn collect_compiler_flags(compiler_path: &Path) -> Features {
let options_path = compiler_path.join("rustc_session/src/options/unstable.rs");
let options_rs = t!(fs::read_to_string(&options_path), options_path);
parse_compiler_flags(&options_rs, &options_path)
}

const DESCRIPTION_FIELD: usize = 3;
const REQUIRED_FIELDS: usize = 4;
const OPTIONAL_FIELDS: usize = 5;

struct ParsedOptionEntry {
name: String,
line: usize,
description: String,
}

struct UnstableOptionsInput {
struct_name: Ident,
entries: Vec<ParsedOptionEntry>,
}

impl Parse for ParsedOptionEntry {
fn parse(input: ParseStream<'_>) -> syn::Result<Self> {
let _attrs = input.call(Attribute::parse_outer)?;

let name: Ident = input.parse()?;
let line = name.span().start().line;
input.parse::<Token![:]>()?;
let _ty: syn::Type = input.parse()?;
input.parse::<Token![=]>()?;

let tuple_content;
parenthesized!(tuple_content in input);
let tuple_tokens: TokenStream = tuple_content.parse()?;
let tuple_fields = split_tuple_fields(tuple_tokens);

if !matches!(tuple_fields.len(), REQUIRED_FIELDS | OPTIONAL_FIELDS) {
return Err(syn::Error::new(
name.span(),
format!(
"unexpected field count for option `{name}`: expected {REQUIRED_FIELDS} or {OPTIONAL_FIELDS}, found {}",
tuple_fields.len()
),
));
}

if tuple_fields.len() == OPTIONAL_FIELDS
&& !is_deprecated_marker_field(&tuple_fields[REQUIRED_FIELDS])
{
return Err(syn::Error::new(
name.span(),
format!(
"unexpected trailing field in option `{name}`: expected `is_deprecated_and_do_nothing: ...`"
),
));
}

let description = parse_description_field(&tuple_fields[DESCRIPTION_FIELD], &name)?;
Ok(Self { name: name.to_string(), line, description })
}
}

impl Parse for UnstableOptionsInput {
fn parse(input: ParseStream<'_>) -> syn::Result<Self> {
let struct_name: Ident = input.parse()?;
input.parse::<Token![,]>()?;
let _tmod_enum_name: Ident = input.parse()?;
input.parse::<Token![,]>()?;
let _stat_name: Ident = input.parse()?;
input.parse::<Token![,]>()?;
let _opt_module_name: Ident = input.parse()?;
input.parse::<Token![,]>()?;
let _prefix: LitStr = input.parse()?;
input.parse::<Token![,]>()?;
let _output_name: LitStr = input.parse()?;
input.parse::<Token![,]>()?;

let entries =
syn::punctuated::Punctuated::<ParsedOptionEntry, Token![,]>::parse_terminated(input)?
.into_iter()
.collect();

Ok(Self { struct_name, entries })
}
}

fn parse_compiler_flags(options_rs: &str, options_path: &Path) -> Features {
let options_input = parse_unstable_options_macro(options_rs).unwrap_or_else(|error| {
panic!("failed to parse unstable options from `{}`: {error}", options_path.display())
});

let mut features = Features::new();
for entry in options_input.entries {
if entry.name == "help" {
continue;
}

features.insert(
entry.name,
Feature {
level: Status::Unstable,
since: None,
has_gate_test: false,
tracking_issue: None,
file: options_path.to_path_buf(),
line: entry.line,
description: Some(entry.description),
},
);
}

features
}

fn parse_unstable_options_macro(source: &str) -> syn::Result<UnstableOptionsInput> {
let ast = syn::parse_file(source)?;

for item in ast.items {
let Item::Macro(item_macro) = item else {
continue;
};

if !item_macro.mac.path.is_ident("options") {
continue;
}

let parsed = syn::parse2::<UnstableOptionsInput>(item_macro.mac.tokens)?;
if parsed.struct_name == "UnstableOptions" {
return Ok(parsed);
}
}

Err(syn::Error::new(
Span::call_site(),
"could not find `options!` invocation for `UnstableOptions`",
))
}

fn parse_description_field(field: &TokenStream, option_name: &Ident) -> syn::Result<String> {
let lit = syn::parse2::<LitStr>(field.clone()).map_err(|_| {
syn::Error::new_spanned(
field.clone(),
format!("expected description string literal in option `{option_name}`"),
)
})?;
Ok(lit.value())
}

fn split_tuple_fields(tuple_tokens: TokenStream) -> Vec<TokenStream> {
let mut fields = Vec::new();
let mut current = TokenStream::new();

for token in tuple_tokens {
if let TokenTree::Punct(punct) = &token {
if punct.as_char() == ',' {
fields.push(current);
current = TokenStream::new();
continue;
}
}
current.extend([token]);
}
fields.push(current);

while matches!(fields.last(), Some(field) if field.is_empty()) {
fields.pop();
}

fields
}

fn is_deprecated_marker_field(field: &TokenStream) -> bool {
let mut tokens = field.clone().into_iter();
let Some(TokenTree::Ident(name)) = tokens.next() else {
return false;
};
let Some(TokenTree::Punct(colon)) = tokens.next() else {
return false;
};
name == "is_deprecated_and_do_nothing" && colon.as_char() == ':'
}

fn main() {
let library_path_str = env::args_os().nth(1).expect("library/ path required");
let compiler_path_str = env::args_os().nth(2).expect("compiler/ path required");
Expand All @@ -316,7 +129,6 @@ fn main() {
.filter(|&(ref name, _)| !lang_features.contains_key(name))
.collect();
let env_vars = collect_env_vars(compiler_path);
let compiler_flags = collect_compiler_flags(compiler_path);

let doc_src_path = src_path.join(PATH_STR);

Expand All @@ -332,17 +144,9 @@ fn main() {
&dest_path.join(LIB_FEATURES_DIR),
&lib_features,
);
generate_feature_files(
&doc_src_path.join(COMPILER_FLAGS_DIR),
&dest_path.join(COMPILER_FLAGS_DIR),
&compiler_flags,
);
generate_env_files(&doc_src_path.join(ENV_VARS_DIR), &dest_path.join(ENV_VARS_DIR), &env_vars);

copy_recursive(&doc_src_path, &dest_path);

generate_summary(&dest_path, &lang_features, &lib_features);
}

#[cfg(test)]
mod tests;
73 changes: 0 additions & 73 deletions src/tools/unstable-book-gen/src/tests.rs
View file
Open in desktop

This file was deleted.

Loading