| // The compiler code necessary to support the env! extension. Eventually this |
| // should all get sucked into either the compiler syntax extension plugin |
| // interface. |
| // |
| |
| use rustc_ast::tokenstream::TokenStream; |
| use rustc_ast::{self as ast, AstDeref, GenericArg}; |
| use rustc_expand::base::{self, *}; |
| use rustc_span::symbol::{kw, sym, Ident, Symbol}; |
| use rustc_span::Span; |
| use std::env; |
| use thin_vec::thin_vec; |
| |
| use crate::errors; |
| |
| pub fn expand_option_env<'cx>( |
| cx: &'cx mut ExtCtxt<'_>, |
| sp: Span, |
| tts: TokenStream, |
| ) -> Box<dyn base::MacResult + 'cx> { |
| let Some(var) = get_single_str_from_tts(cx, sp, tts, "option_env!") else { |
| return DummyResult::any(sp); |
| }; |
| |
| let sp = cx.with_def_site_ctxt(sp); |
| let value = env::var(var.as_str()).ok().as_deref().map(Symbol::intern); |
| cx.sess.parse_sess.env_depinfo.borrow_mut().insert((var, value)); |
| let e = match value { |
| None => { |
| let lt = cx.lifetime(sp, Ident::new(kw::StaticLifetime, sp)); |
| cx.expr_path(cx.path_all( |
| sp, |
| true, |
| cx.std_path(&[sym::option, sym::Option, sym::None]), |
| vec![GenericArg::Type(cx.ty_ref( |
| sp, |
| cx.ty_ident(sp, Ident::new(sym::str, sp)), |
| Some(lt), |
| ast::Mutability::Not, |
| ))], |
| )) |
| } |
| Some(value) => cx.expr_call_global( |
| sp, |
| cx.std_path(&[sym::option, sym::Option, sym::Some]), |
| thin_vec![cx.expr_str(sp, value)], |
| ), |
| }; |
| MacEager::expr(e) |
| } |
| |
| pub fn expand_env<'cx>( |
| cx: &'cx mut ExtCtxt<'_>, |
| sp: Span, |
| tts: TokenStream, |
| ) -> Box<dyn base::MacResult + 'cx> { |
| let mut exprs = match get_exprs_from_tts(cx, tts) { |
| Some(exprs) if exprs.is_empty() || exprs.len() > 2 => { |
| cx.emit_err(errors::EnvTakesArgs { span: sp }); |
| return DummyResult::any(sp); |
| } |
| None => return DummyResult::any(sp), |
| Some(exprs) => exprs.into_iter(), |
| }; |
| |
| let var_expr = exprs.next().unwrap(); |
| let Some((var, _)) = expr_to_string(cx, var_expr.clone(), "expected string literal") else { |
| return DummyResult::any(sp); |
| }; |
| |
| let custom_msg = match exprs.next() { |
| None => None, |
| Some(second) => match expr_to_string(cx, second, "expected string literal") { |
| None => return DummyResult::any(sp), |
| Some((s, _)) => Some(s), |
| }, |
| }; |
| |
| let span = cx.with_def_site_ctxt(sp); |
| let value = env::var(var.as_str()).ok().as_deref().map(Symbol::intern); |
| cx.sess.parse_sess.env_depinfo.borrow_mut().insert((var, value)); |
| let e = match value { |
| None => { |
| let ast::ExprKind::Lit(ast::token::Lit { |
| kind: ast::token::LitKind::Str | ast::token::LitKind::StrRaw(..), |
| symbol, |
| .. |
| }) = &var_expr.kind |
| else { |
| unreachable!("`expr_to_string` ensures this is a string lit") |
| }; |
| |
| if let Some(msg_from_user) = custom_msg { |
| cx.emit_err(errors::EnvNotDefinedWithUserMessage { span, msg_from_user }); |
| } else if is_cargo_env_var(var.as_str()) { |
| cx.emit_err(errors::EnvNotDefined::CargoEnvVar { |
| span, |
| var: *symbol, |
| var_expr: var_expr.ast_deref(), |
| }); |
| } else { |
| cx.emit_err(errors::EnvNotDefined::CustomEnvVar { |
| span, |
| var: *symbol, |
| var_expr: var_expr.ast_deref(), |
| }); |
| } |
| |
| return DummyResult::any(sp); |
| } |
| Some(value) => cx.expr_str(span, value), |
| }; |
| MacEager::expr(e) |
| } |
| |
| /// Returns `true` if an environment variable from `env!` is one used by Cargo. |
| fn is_cargo_env_var(var: &str) -> bool { |
| var.starts_with("CARGO_") |
| || var.starts_with("DEP_") |
| || matches!(var, "OUT_DIR" | "OPT_LEVEL" | "PROFILE" | "HOST" | "TARGET") |
| } |