Make compile_error! lazy and emit a diagnostic

This commit is contained in:
Jonas Schievink 2020-12-03 15:31:04 +01:00
parent 4634bfb332
commit 883c8d177d
3 changed files with 34 additions and 21 deletions

View file

@ -84,6 +84,9 @@ macro_rules! env {}
#[rustc_builtin_macro]
macro_rules! include {}
#[rustc_builtin_macro]
macro_rules! compile_error {}
#[rustc_builtin_macro]
macro_rules! format_args {
() => {}
@ -103,6 +106,9 @@ fn f() {
env!("OUT_DIR");
//^^^^^^^^^^^^^^^ `OUT_DIR` not set, enable "load out dirs from check" to fix
compile_error!("compile_error works");
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `compile_error!` called: compile_error works
// Lazy:
format_args!();

View file

@ -86,7 +86,6 @@ pub fn find_builtin_macro(
register_builtin! {
LAZY:
(column, Column) => column_expand,
(compile_error, CompileError) => compile_error_expand,
(file, File) => file_expand,
(line, Line) => line_expand,
(assert, Assert) => assert_expand,
@ -97,6 +96,7 @@ register_builtin! {
(format_args_nl, FormatArgsNl) => format_args_expand,
EAGER:
(compile_error, CompileError) => compile_error_expand,
(concat, Concat) => concat_expand,
(include, Include) => include_expand,
(include_bytes, IncludeBytes) => include_bytes_expand,
@ -213,25 +213,6 @@ fn file_expand(
ExpandResult::ok(expanded)
}
fn compile_error_expand(
_db: &dyn AstDatabase,
_id: LazyMacroId,
tt: &tt::Subtree,
) -> ExpandResult<tt::Subtree> {
if tt.count() == 1 {
if let tt::TokenTree::Leaf(tt::Leaf::Literal(it)) = &tt.token_trees[0] {
let s = it.text.as_str();
if s.contains('"') {
return ExpandResult::ok(quote! { loop { #it }});
}
};
}
ExpandResult::only_err(mbe::ExpandError::BindingError(
"`compile_error!` argument be a string".into(),
))
}
fn format_args_expand(
_db: &dyn AstDatabase,
_id: LazyMacroId,
@ -280,6 +261,30 @@ fn unquote_str(lit: &tt::Literal) -> Option<String> {
token.value().map(|it| it.into_owned())
}
fn compile_error_expand(
_db: &dyn AstDatabase,
_id: EagerMacroId,
tt: &tt::Subtree,
) -> ExpandResult<Option<(tt::Subtree, FragmentKind)>> {
let err = match &*tt.token_trees {
[tt::TokenTree::Leaf(tt::Leaf::Literal(it))] => {
let text = it.text.as_str();
if text.starts_with('"') && text.ends_with('"') {
// FIXME: does not handle raw strings
mbe::ExpandError::Other(format!(
"`compile_error!` called: {}",
&text[1..text.len() - 1]
))
} else {
mbe::ExpandError::BindingError("`compile_error!` argument must be a string".into())
}
}
_ => mbe::ExpandError::BindingError("`compile_error!` argument must be a string".into()),
};
ExpandResult { value: Some((quote! {}, FragmentKind::Items)), err: Some(err) }
}
fn concat_expand(
_db: &dyn AstDatabase,
_arg_id: EagerMacroId,
@ -646,7 +651,8 @@ mod tests {
"#,
);
assert_eq!(expanded, r#"loop{"error!"}"#);
// This expands to nothing (since it's in item position), but emits an error.
assert_eq!(expanded, "");
}
#[test]

View file

@ -207,6 +207,7 @@ fn macro_expand_with_arg(
} else {
return ExpandResult {
value: Some(db.lookup_intern_eager_expansion(id).subtree),
// FIXME: There could be errors here!
err: None,
};
}