1 // The compiler code necessary to support the env! extension. Eventually this
2 // should all get sucked into either the compiler syntax extension plugin
6 use rustc_ast::tokenstream::TokenStream;
7 use rustc_ast::{self as ast, GenericArg};
8 use rustc_expand::base::{self, *};
9 use rustc_span::symbol::{kw, sym, Ident, Symbol};
14 pub fn expand_option_env<'cx>(
15 cx: &'cx mut ExtCtxt<'_>,
18 ) -> Box<dyn base::MacResult + 'cx> {
19 let Some(var) = get_single_str_from_tts(cx, sp, tts, "option_env!") else {
20 return DummyResult::any(sp);
23 let sp = cx.with_def_site_ctxt(sp);
24 let value = env::var(var.as_str()).ok().as_deref().map(Symbol::intern);
25 cx.sess.parse_sess.env_depinfo.borrow_mut().insert((var, value));
28 let lt = cx.lifetime(sp, Ident::new(kw::StaticLifetime, sp));
29 cx.expr_path(cx.path_all(
32 cx.std_path(&[sym::option, sym::Option, sym::None]),
33 vec![GenericArg::Type(cx.ty_ref(
35 cx.ty_ident(sp, Ident::new(sym::str, sp)),
41 Some(value) => cx.expr_call_global(
43 cx.std_path(&[sym::option, sym::Option, sym::Some]),
44 vec![cx.expr_str(sp, value)],
50 pub fn expand_env<'cx>(
51 cx: &'cx mut ExtCtxt<'_>,
54 ) -> Box<dyn base::MacResult + 'cx> {
55 let mut exprs = match get_exprs_from_tts(cx, tts) {
56 Some(exprs) if exprs.is_empty() => {
57 cx.span_err(sp, "env! takes 1 or 2 arguments");
58 return DummyResult::any(sp);
60 None => return DummyResult::any(sp),
61 Some(exprs) => exprs.into_iter(),
64 let Some((var, _style)) = expr_to_string(cx, exprs.next().unwrap(), "expected string literal") else {
65 return DummyResult::any(sp);
67 let msg = match exprs.next() {
68 None => Symbol::intern(&format!("environment variable `{}` not defined", var)),
69 Some(second) => match expr_to_string(cx, second, "expected string literal") {
70 None => return DummyResult::any(sp),
71 Some((s, _style)) => s,
75 if exprs.next().is_some() {
76 cx.span_err(sp, "env! takes 1 or 2 arguments");
77 return DummyResult::any(sp);
80 let sp = cx.with_def_site_ctxt(sp);
81 let value = env::var(var.as_str()).ok().as_deref().map(Symbol::intern);
82 cx.sess.parse_sess.env_depinfo.borrow_mut().insert((var, value));
85 cx.span_err(sp, msg.as_str());
86 return DummyResult::any(sp);
88 Some(value) => cx.expr_str(sp, value),