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|
// 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;
fn lookup_env<'cx>(cx: &'cx ExtCtxt<'_>, var: Symbol) -> Option<Symbol> {
let var = var.as_str();
if let Some(value) = cx.sess.opts.logical_env.get(var) {
return Some(Symbol::intern(value));
}
// If the environment variable was not defined with the `--env` option, we try to retrieve it
// from rustc's environment.
env::var(var).ok().as_deref().map(Symbol::intern)
}
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 = lookup_env(cx, var);
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 = lookup_env(cx, var);
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")
}
|
