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use crate::base::{self, *};
use crate::proc_macro_server;
use rustc_ast as ast;
use rustc_ast::ptr::P;
use rustc_ast::token;
use rustc_ast::tokenstream::TokenStream;
use rustc_data_structures::sync::Lrc;
use rustc_errors::ErrorGuaranteed;
use rustc_parse::parser::ForceCollect;
use rustc_session::config::ProcMacroExecutionStrategy;
use rustc_span::profiling::SpannedEventArgRecorder;
use rustc_span::{Span, DUMMY_SP};
struct CrossbeamMessagePipe<T> {
tx: crossbeam_channel::Sender<T>,
rx: crossbeam_channel::Receiver<T>,
}
impl<T> pm::bridge::server::MessagePipe<T> for CrossbeamMessagePipe<T> {
fn new() -> (Self, Self) {
let (tx1, rx1) = crossbeam_channel::bounded(1);
let (tx2, rx2) = crossbeam_channel::bounded(1);
(CrossbeamMessagePipe { tx: tx1, rx: rx2 }, CrossbeamMessagePipe { tx: tx2, rx: rx1 })
}
fn send(&mut self, value: T) {
self.tx.send(value).unwrap();
}
fn recv(&mut self) -> Option<T> {
self.rx.recv().ok()
}
}
fn exec_strategy(ecx: &ExtCtxt<'_>) -> impl pm::bridge::server::ExecutionStrategy {
pm::bridge::server::MaybeCrossThread::<CrossbeamMessagePipe<_>>::new(
ecx.sess.opts.unstable_opts.proc_macro_execution_strategy
== ProcMacroExecutionStrategy::CrossThread,
)
}
pub struct BangProcMacro {
pub client: pm::bridge::client::Client<pm::TokenStream, pm::TokenStream>,
}
impl base::BangProcMacro for BangProcMacro {
fn expand<'cx>(
&self,
ecx: &'cx mut ExtCtxt<'_>,
span: Span,
input: TokenStream,
) -> Result<TokenStream, ErrorGuaranteed> {
let _timer =
ecx.sess.prof.generic_activity_with_arg_recorder("expand_proc_macro", |recorder| {
recorder.record_arg_with_span(ecx.expansion_descr(), span);
});
let proc_macro_backtrace = ecx.ecfg.proc_macro_backtrace;
let strategy = exec_strategy(ecx);
let server = proc_macro_server::Rustc::new(ecx);
self.client.run(&strategy, server, input, proc_macro_backtrace).map_err(|e| {
let mut err = ecx.struct_span_err(span, "proc macro panicked");
if let Some(s) = e.as_str() {
err.help(&format!("message: {}", s));
}
err.emit()
})
}
}
pub struct AttrProcMacro {
pub client: pm::bridge::client::Client<(pm::TokenStream, pm::TokenStream), pm::TokenStream>,
}
impl base::AttrProcMacro for AttrProcMacro {
fn expand<'cx>(
&self,
ecx: &'cx mut ExtCtxt<'_>,
span: Span,
annotation: TokenStream,
annotated: TokenStream,
) -> Result<TokenStream, ErrorGuaranteed> {
let _timer =
ecx.sess.prof.generic_activity_with_arg_recorder("expand_proc_macro", |recorder| {
recorder.record_arg_with_span(ecx.expansion_descr(), span);
});
let proc_macro_backtrace = ecx.ecfg.proc_macro_backtrace;
let strategy = exec_strategy(ecx);
let server = proc_macro_server::Rustc::new(ecx);
self.client.run(&strategy, server, annotation, annotated, proc_macro_backtrace).map_err(
|e| {
let mut err = ecx.struct_span_err(span, "custom attribute panicked");
if let Some(s) = e.as_str() {
err.help(&format!("message: {}", s));
}
err.emit()
},
)
}
}
pub struct DeriveProcMacro {
pub client: pm::bridge::client::Client<pm::TokenStream, pm::TokenStream>,
}
impl MultiItemModifier for DeriveProcMacro {
fn expand(
&self,
ecx: &mut ExtCtxt<'_>,
span: Span,
_meta_item: &ast::MetaItem,
item: Annotatable,
) -> ExpandResult<Vec<Annotatable>, Annotatable> {
let is_stmt = matches!(item, Annotatable::Stmt(..));
let hack = crate::base::ann_pretty_printing_compatibility_hack(&item, &ecx.sess.parse_sess);
let input = if hack {
let nt = match item {
Annotatable::Item(item) => token::NtItem(item),
Annotatable::Stmt(stmt) => token::NtStmt(stmt),
_ => unreachable!(),
};
TokenStream::token_alone(token::Interpolated(Lrc::new(nt)), DUMMY_SP)
} else {
item.to_tokens()
};
let stream = {
let _timer =
ecx.sess.prof.generic_activity_with_arg_recorder("expand_proc_macro", |recorder| {
recorder.record_arg_with_span(ecx.expansion_descr(), span);
});
let proc_macro_backtrace = ecx.ecfg.proc_macro_backtrace;
let strategy = exec_strategy(ecx);
let server = proc_macro_server::Rustc::new(ecx);
match self.client.run(&strategy, server, input, proc_macro_backtrace) {
Ok(stream) => stream,
Err(e) => {
let mut err = ecx.struct_span_err(span, "proc-macro derive panicked");
if let Some(s) = e.as_str() {
err.help(&format!("message: {}", s));
}
err.emit();
return ExpandResult::Ready(vec![]);
}
}
};
let error_count_before = ecx.sess.parse_sess.span_diagnostic.err_count();
let mut parser =
rustc_parse::stream_to_parser(&ecx.sess.parse_sess, stream, Some("proc-macro derive"));
let mut items = vec![];
loop {
match parser.parse_item(ForceCollect::No) {
Ok(None) => break,
Ok(Some(item)) => {
if is_stmt {
items.push(Annotatable::Stmt(P(ecx.stmt_item(span, item))));
} else {
items.push(Annotatable::Item(item));
}
}
Err(mut err) => {
err.emit();
break;
}
}
}
if ecx.sess.parse_sess.span_diagnostic.err_count() > error_count_before {
ecx.struct_span_err(span, "proc-macro derive produced unparseable tokens").emit();
}
ExpandResult::Ready(items)
}
}
