| // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| /// Module-level assembly support. |
| /// |
| /// The macro defined here allows you to specify "top-level", |
| /// "file-scoped", or "module-level" assembly. These synonyms |
| /// all correspond to LLVM's module-level inline assembly instruction. |
| /// |
| /// For example, `global_asm!("some assembly here")` codegens to |
| /// LLVM's `module asm "some assembly here"`. All of LLVM's caveats |
| /// therefore apply. |
| |
| use syntax::ast; |
| use syntax::source_map::respan; |
| use syntax::ext::base; |
| use syntax::ext::base::*; |
| use syntax::feature_gate; |
| use syntax::ptr::P; |
| use syntax::symbol::Symbol; |
| use syntax_pos::Span; |
| use syntax::tokenstream; |
| |
| pub const MACRO: &str = "global_asm"; |
| |
| pub fn expand_global_asm<'cx>(cx: &'cx mut ExtCtxt, |
| sp: Span, |
| tts: &[tokenstream::TokenTree]) -> Box<dyn base::MacResult + 'cx> { |
| if !cx.ecfg.enable_global_asm() { |
| feature_gate::emit_feature_err(&cx.parse_sess, |
| MACRO, |
| sp, |
| feature_gate::GateIssue::Language, |
| feature_gate::EXPLAIN_GLOBAL_ASM); |
| return DummyResult::any(sp); |
| } |
| |
| let mut p = cx.new_parser_from_tts(tts); |
| let (asm, _) = match expr_to_string(cx, |
| panictry!(p.parse_expr()), |
| "inline assembly must be a string literal") { |
| Some((s, st)) => (s, st), |
| None => return DummyResult::any(sp), |
| }; |
| |
| MacEager::items(smallvec![P(ast::Item { |
| ident: ast::Ident::with_empty_ctxt(Symbol::intern("")), |
| attrs: Vec::new(), |
| id: ast::DUMMY_NODE_ID, |
| node: ast::ItemKind::GlobalAsm(P(ast::GlobalAsm { |
| asm, |
| ctxt: cx.backtrace(), |
| })), |
| vis: respan(sp.shrink_to_lo(), ast::VisibilityKind::Inherited), |
| span: sp, |
| tokens: None, |
| })]) |
| } |