rust/compiler/rustc_builtin_macros/src/cmdline_attrs.rs

//! Attributes injected into the crate root from command line using `-Z crate-attr`.

use rustc_ast::attr::mk_attr;
use rustc_ast::{self as ast, AttrItem, AttrStyle, token};
use rustc_parse::parser::ForceCollect;
use rustc_parse::{new_parser_from_source_str, unwrap_or_emit_fatal};
use rustc_session::parse::ParseSess;
use rustc_span::FileName;

use crate::errors;

pub fn inject(krate: &mut ast::Crate, psess: &ParseSess, attrs: &[String]) {
    for raw_attr in attrs {
        let mut parser = unwrap_or_emit_fatal(new_parser_from_source_str(
            psess,
            FileName::cli_crate_attr_source_code(raw_attr),
            raw_attr.clone(),
        ));

        let start_span = parser.token.span;
        let AttrItem { unsafety, path, args, tokens: _ } =
            match parser.parse_attr_item(ForceCollect::No) {
                Ok(ai) => ai,
                Err(err) => {
                    err.emit();
                    continue;
                }
            };
        let end_span = parser.token.span;
        if parser.token != token::Eof {
            psess.dcx().emit_err(errors::InvalidCrateAttr { span: start_span.to(end_span) });
            continue;
        }

        krate.attrs.push(mk_attr(
            &psess.attr_id_generator,
            AttrStyle::Inner,
            unsafety,
            path,
            args,
            start_span.to(end_span),
        ));
    }
}