| use std::mem; |
| |
| use smallvec::smallvec; |
| use syntax::ast::{self, Ident}; |
| use syntax::attr; |
| use syntax::ext::base::ExtCtxt; |
| use syntax::ext::expand::{AstFragment, ExpansionConfig}; |
| use syntax::ext::proc_macro::is_proc_macro_attr; |
| use syntax::parse::ParseSess; |
| use syntax::ptr::P; |
| use syntax::symbol::{kw, sym}; |
| use syntax::visit::{self, Visitor}; |
| use syntax_pos::{Span, DUMMY_SP}; |
| use syntax_pos::hygiene::AstPass; |
| |
| struct ProcMacroDerive { |
| trait_name: ast::Name, |
| function_name: Ident, |
| span: Span, |
| attrs: Vec<ast::Name>, |
| } |
| |
| struct ProcMacroDef { |
| function_name: Ident, |
| span: Span, |
| } |
| |
| struct CollectProcMacros<'a> { |
| derives: Vec<ProcMacroDerive>, |
| attr_macros: Vec<ProcMacroDef>, |
| bang_macros: Vec<ProcMacroDef>, |
| in_root: bool, |
| handler: &'a errors::Handler, |
| is_proc_macro_crate: bool, |
| is_test_crate: bool, |
| } |
| |
| pub fn inject(sess: &ParseSess, |
| resolver: &mut dyn (::syntax::ext::base::Resolver), |
| mut krate: ast::Crate, |
| is_proc_macro_crate: bool, |
| has_proc_macro_decls: bool, |
| is_test_crate: bool, |
| num_crate_types: usize, |
| handler: &errors::Handler) -> ast::Crate { |
| let ecfg = ExpansionConfig::default("proc_macro".to_string()); |
| let mut cx = ExtCtxt::new(sess, ecfg, resolver); |
| |
| let (derives, attr_macros, bang_macros) = { |
| let mut collect = CollectProcMacros { |
| derives: Vec::new(), |
| attr_macros: Vec::new(), |
| bang_macros: Vec::new(), |
| in_root: true, |
| handler, |
| is_proc_macro_crate, |
| is_test_crate, |
| }; |
| if has_proc_macro_decls || is_proc_macro_crate { |
| visit::walk_crate(&mut collect, &krate); |
| } |
| (collect.derives, collect.attr_macros, collect.bang_macros) |
| }; |
| |
| if !is_proc_macro_crate { |
| return krate |
| } |
| |
| if num_crate_types > 1 { |
| handler.err("cannot mix `proc-macro` crate type with others"); |
| } |
| |
| if is_test_crate { |
| return krate; |
| } |
| |
| krate.module.items.push(mk_decls(&mut cx, &derives, &attr_macros, &bang_macros)); |
| |
| krate |
| } |
| |
| impl<'a> CollectProcMacros<'a> { |
| fn check_not_pub_in_root(&self, vis: &ast::Visibility, sp: Span) { |
| if self.is_proc_macro_crate && self.in_root && vis.node.is_pub() { |
| self.handler.span_err(sp, |
| "`proc-macro` crate types cannot \ |
| export any items other than functions \ |
| tagged with `#[proc_macro_derive]` currently"); |
| } |
| } |
| |
| fn collect_custom_derive(&mut self, item: &'a ast::Item, attr: &'a ast::Attribute) { |
| // Once we've located the `#[proc_macro_derive]` attribute, verify |
| // that it's of the form `#[proc_macro_derive(Foo)]` or |
| // `#[proc_macro_derive(Foo, attributes(A, ..))]` |
| let list = match attr.meta_item_list() { |
| Some(list) => list, |
| None => return, |
| }; |
| if list.len() != 1 && list.len() != 2 { |
| self.handler.span_err(attr.span, |
| "attribute must have either one or two arguments"); |
| return |
| } |
| let trait_attr = match list[0].meta_item() { |
| Some(meta_item) => meta_item, |
| _ => { |
| self.handler.span_err(list[0].span(), "not a meta item"); |
| return |
| } |
| }; |
| let trait_ident = match trait_attr.ident() { |
| Some(trait_ident) if trait_attr.is_word() => trait_ident, |
| _ => { |
| self.handler.span_err(trait_attr.span, "must only be one word"); |
| return |
| } |
| }; |
| |
| if !trait_ident.name.can_be_raw() { |
| self.handler.span_err(trait_attr.span, |
| &format!("`{}` cannot be a name of derive macro", trait_ident)); |
| } |
| |
| let attributes_attr = list.get(1); |
| let proc_attrs: Vec<_> = if let Some(attr) = attributes_attr { |
| if !attr.check_name(sym::attributes) { |
| self.handler.span_err(attr.span(), "second argument must be `attributes`") |
| } |
| attr.meta_item_list().unwrap_or_else(|| { |
| self.handler.span_err(attr.span(), |
| "attribute must be of form: `attributes(foo, bar)`"); |
| &[] |
| }).into_iter().filter_map(|attr| { |
| let attr = match attr.meta_item() { |
| Some(meta_item) => meta_item, |
| _ => { |
| self.handler.span_err(attr.span(), "not a meta item"); |
| return None; |
| } |
| }; |
| |
| let ident = match attr.ident() { |
| Some(ident) if attr.is_word() => ident, |
| _ => { |
| self.handler.span_err(attr.span, "must only be one word"); |
| return None; |
| } |
| }; |
| if !ident.name.can_be_raw() { |
| self.handler.span_err( |
| attr.span, |
| &format!("`{}` cannot be a name of derive helper attribute", ident), |
| ); |
| } |
| |
| Some(ident.name) |
| }).collect() |
| } else { |
| Vec::new() |
| }; |
| |
| if self.in_root && item.vis.node.is_pub() { |
| self.derives.push(ProcMacroDerive { |
| span: item.span, |
| trait_name: trait_ident.name, |
| function_name: item.ident, |
| attrs: proc_attrs, |
| }); |
| } else { |
| let msg = if !self.in_root { |
| "functions tagged with `#[proc_macro_derive]` must \ |
| currently reside in the root of the crate" |
| } else { |
| "functions tagged with `#[proc_macro_derive]` must be `pub`" |
| }; |
| self.handler.span_err(item.span, msg); |
| } |
| } |
| |
| fn collect_attr_proc_macro(&mut self, item: &'a ast::Item) { |
| if self.in_root && item.vis.node.is_pub() { |
| self.attr_macros.push(ProcMacroDef { |
| span: item.span, |
| function_name: item.ident, |
| }); |
| } else { |
| let msg = if !self.in_root { |
| "functions tagged with `#[proc_macro_attribute]` must \ |
| currently reside in the root of the crate" |
| } else { |
| "functions tagged with `#[proc_macro_attribute]` must be `pub`" |
| }; |
| self.handler.span_err(item.span, msg); |
| } |
| } |
| |
| fn collect_bang_proc_macro(&mut self, item: &'a ast::Item) { |
| if self.in_root && item.vis.node.is_pub() { |
| self.bang_macros.push(ProcMacroDef { |
| span: item.span, |
| function_name: item.ident, |
| }); |
| } else { |
| let msg = if !self.in_root { |
| "functions tagged with `#[proc_macro]` must \ |
| currently reside in the root of the crate" |
| } else { |
| "functions tagged with `#[proc_macro]` must be `pub`" |
| }; |
| self.handler.span_err(item.span, msg); |
| } |
| } |
| } |
| |
| impl<'a> Visitor<'a> for CollectProcMacros<'a> { |
| fn visit_item(&mut self, item: &'a ast::Item) { |
| if let ast::ItemKind::MacroDef(..) = item.node { |
| if self.is_proc_macro_crate && attr::contains_name(&item.attrs, sym::macro_export) { |
| let msg = |
| "cannot export macro_rules! macros from a `proc-macro` crate type currently"; |
| self.handler.span_err(item.span, msg); |
| } |
| } |
| |
| // First up, make sure we're checking a bare function. If we're not then |
| // we're just not interested in this item. |
| // |
| // If we find one, try to locate a `#[proc_macro_derive]` attribute on it. |
| let is_fn = match item.node { |
| ast::ItemKind::Fn(..) => true, |
| _ => false, |
| }; |
| |
| let mut found_attr: Option<&'a ast::Attribute> = None; |
| |
| for attr in &item.attrs { |
| if is_proc_macro_attr(&attr) { |
| if let Some(prev_attr) = found_attr { |
| let msg = if attr.path.segments[0].ident.name == |
| prev_attr.path.segments[0].ident.name { |
| format!("only one `#[{}]` attribute is allowed on any given function", |
| attr.path) |
| } else { |
| format!("`#[{}]` and `#[{}]` attributes cannot both be applied \ |
| to the same function", attr.path, prev_attr.path) |
| }; |
| |
| self.handler.struct_span_err(attr.span, &msg) |
| .span_note(prev_attr.span, "previous attribute here") |
| .emit(); |
| |
| return; |
| } |
| |
| found_attr = Some(attr); |
| } |
| } |
| |
| let attr = match found_attr { |
| None => { |
| self.check_not_pub_in_root(&item.vis, item.span); |
| let prev_in_root = mem::replace(&mut self.in_root, false); |
| visit::walk_item(self, item); |
| self.in_root = prev_in_root; |
| return; |
| }, |
| Some(attr) => attr, |
| }; |
| |
| if !is_fn { |
| let msg = format!("the `#[{}]` attribute may only be used on bare functions", |
| attr.path); |
| |
| self.handler.span_err(attr.span, &msg); |
| return; |
| } |
| |
| if self.is_test_crate { |
| return; |
| } |
| |
| if !self.is_proc_macro_crate { |
| let msg = format!("the `#[{}]` attribute is only usable with crates of the \ |
| `proc-macro` crate type", attr.path); |
| |
| self.handler.span_err(attr.span, &msg); |
| return; |
| } |
| |
| if attr.check_name(sym::proc_macro_derive) { |
| self.collect_custom_derive(item, attr); |
| } else if attr.check_name(sym::proc_macro_attribute) { |
| self.collect_attr_proc_macro(item); |
| } else if attr.check_name(sym::proc_macro) { |
| self.collect_bang_proc_macro(item); |
| }; |
| |
| let prev_in_root = mem::replace(&mut self.in_root, false); |
| visit::walk_item(self, item); |
| self.in_root = prev_in_root; |
| } |
| |
| fn visit_mac(&mut self, mac: &'a ast::Mac) { |
| visit::walk_mac(self, mac) |
| } |
| } |
| |
| // Creates a new module which looks like: |
| // |
| // const _: () = { |
| // extern crate proc_macro; |
| // |
| // use proc_macro::bridge::client::ProcMacro; |
| // |
| // #[rustc_proc_macro_decls] |
| // static DECLS: &[ProcMacro] = &[ |
| // ProcMacro::custom_derive($name_trait1, &[], ::$name1); |
| // ProcMacro::custom_derive($name_trait2, &["attribute_name"], ::$name2); |
| // // ... |
| // ]; |
| // } |
| fn mk_decls( |
| cx: &mut ExtCtxt<'_>, |
| custom_derives: &[ProcMacroDerive], |
| custom_attrs: &[ProcMacroDef], |
| custom_macros: &[ProcMacroDef], |
| ) -> P<ast::Item> { |
| let expn_id = cx.resolver.expansion_for_ast_pass( |
| DUMMY_SP, |
| AstPass::ProcMacroHarness, |
| &[sym::rustc_attrs, sym::proc_macro_internals], |
| None, |
| ); |
| let span = DUMMY_SP.with_def_site_ctxt(expn_id); |
| |
| let proc_macro = Ident::new(sym::proc_macro, span); |
| let krate = cx.item(span, |
| proc_macro, |
| Vec::new(), |
| ast::ItemKind::ExternCrate(None)); |
| |
| let bridge = cx.ident_of("bridge", span); |
| let client = cx.ident_of("client", span); |
| let proc_macro_ty = cx.ident_of("ProcMacro", span); |
| let custom_derive = cx.ident_of("custom_derive", span); |
| let attr = cx.ident_of("attr", span); |
| let bang = cx.ident_of("bang", span); |
| |
| let decls = { |
| let local_path = |sp: Span, name| { |
| cx.expr_path(cx.path(sp.with_ctxt(span.ctxt()), vec![name])) |
| }; |
| let proc_macro_ty_method_path = |method| cx.expr_path(cx.path(span, vec![ |
| proc_macro, bridge, client, proc_macro_ty, method, |
| ])); |
| custom_derives.iter().map(|cd| { |
| cx.expr_call(span, proc_macro_ty_method_path(custom_derive), vec![ |
| cx.expr_str(cd.span, cd.trait_name), |
| cx.expr_vec_slice( |
| span, |
| cd.attrs.iter().map(|&s| cx.expr_str(cd.span, s)).collect::<Vec<_>>() |
| ), |
| local_path(cd.span, cd.function_name), |
| ]) |
| }).chain(custom_attrs.iter().map(|ca| { |
| cx.expr_call(span, proc_macro_ty_method_path(attr), vec![ |
| cx.expr_str(ca.span, ca.function_name.name), |
| local_path(ca.span, ca.function_name), |
| ]) |
| })).chain(custom_macros.iter().map(|cm| { |
| cx.expr_call(span, proc_macro_ty_method_path(bang), vec![ |
| cx.expr_str(cm.span, cm.function_name.name), |
| local_path(cm.span, cm.function_name), |
| ]) |
| })).collect() |
| }; |
| |
| let decls_static = cx.item_static( |
| span, |
| cx.ident_of("_DECLS", span), |
| cx.ty_rptr(span, |
| cx.ty(span, ast::TyKind::Slice( |
| cx.ty_path(cx.path(span, |
| vec![proc_macro, bridge, client, proc_macro_ty])))), |
| None, ast::Mutability::Immutable), |
| ast::Mutability::Immutable, |
| cx.expr_vec_slice(span, decls), |
| ).map(|mut i| { |
| let attr = cx.meta_word(span, sym::rustc_proc_macro_decls); |
| i.attrs.push(cx.attribute(attr)); |
| i |
| }); |
| |
| let block = cx.expr_block(cx.block( |
| span, |
| vec![cx.stmt_item(span, krate), cx.stmt_item(span, decls_static)], |
| )); |
| |
| let anon_constant = cx.item_const( |
| span, |
| ast::Ident::new(kw::Underscore, span), |
| cx.ty(span, ast::TyKind::Tup(Vec::new())), |
| block, |
| ); |
| |
| // Integrate the new item into existing module structures. |
| let items = AstFragment::Items(smallvec![anon_constant]); |
| cx.monotonic_expander().fully_expand_fragment(items).make_items().pop().unwrap() |
| } |