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::ast::{self, GenericArg};
7 use rustc_ast::tokenstream::TokenStream;
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 var = match get_single_str_from_tts(cx, sp, tts, "option_env!") {
20 None => return DummyResult::any(sp),
24 let sp = cx.with_def_site_ctxt(sp);
25 let e = match env::var(&var.as_str()) {
27 let lt = cx.lifetime(sp, Ident::new(kw::StaticLifetime, sp));
28 cx.expr_path(cx.path_all(
31 cx.std_path(&[sym::option, sym::Option, sym::None]),
32 vec![GenericArg::Type(cx.ty_rptr(
34 cx.ty_ident(sp, Ident::new(sym::str, sp)),
40 Ok(s) => cx.expr_call_global(
42 cx.std_path(&[sym::option, sym::Option, sym::Some]),
43 vec![cx.expr_str(sp, Symbol::intern(&s))],
49 pub fn expand_env<'cx>(
50 cx: &'cx mut ExtCtxt<'_>,
53 ) -> Box<dyn base::MacResult + 'cx> {
54 let mut exprs = match get_exprs_from_tts(cx, sp, tts) {
55 Some(ref exprs) if exprs.is_empty() => {
56 cx.span_err(sp, "env! takes 1 or 2 arguments");
57 return DummyResult::any(sp);
59 None => return DummyResult::any(sp),
60 Some(exprs) => exprs.into_iter(),
63 let var = match expr_to_string(cx, exprs.next().unwrap(), "expected string literal") {
64 None => return DummyResult::any(sp),
65 Some((v, _style)) => v,
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 e = match env::var(&*var.as_str()) {
82 cx.span_err(sp, &msg.as_str());
83 return DummyResult::any(sp);
85 Ok(s) => cx.expr_str(sp, Symbol::intern(&s)),