Check for macros in built-in attributes that don't support them.

1 files changed, 25 insertions, 5 deletions

diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index cb7529b527e..0a6d76c99b7 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -23,7 +23,7 @@ use rustc_middle::middle::cstore::{MetadataLoader, MetadataLoaderDyn};
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, GlobalCtxt, ResolverOutputs, TyCtxt};
 use rustc_mir_build as mir_build;
-use rustc_parse::{parse_crate_from_file, parse_crate_from_source_str};
+use rustc_parse::{parse_crate_from_file, parse_crate_from_source_str, validate_attr};
 use rustc_passes::{self, hir_stats, layout_test};
 use rustc_plugin_impl as plugin;
 use rustc_query_impl::{OnDiskCache, Queries as TcxQueries};
@@ -33,8 +33,8 @@ use rustc_session::config::{CrateType, Input, OutputFilenames, OutputType, PpMod
 use rustc_session::lint;
 use rustc_session::output::{filename_for_input, filename_for_metadata};
 use rustc_session::search_paths::PathKind;
-use rustc_session::Session;
-use rustc_span::symbol::{Ident, Symbol};
+use rustc_session::{Limit, Session};
+use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::FileName;
 use rustc_trait_selection::traits;
 use rustc_typeck as typeck;
@@ -311,8 +311,7 @@ pub fn configure_and_expand(
 
         // Create the config for macro expansion
         let features = sess.features_untracked();
-        let recursion_limit =
-            rustc_middle::middle::limits::get_recursion_limit(&krate.attrs, &sess);
+        let recursion_limit = get_recursion_limit(&krate.attrs, &sess);
         let cfg = rustc_expand::expand::ExpansionConfig {
             features: Some(&features),
             recursion_limit,
@@ -1070,3 +1069,24 @@ pub fn start_codegen<'tcx>(
 
     codegen
 }
+
+fn get_recursion_limit(krate_attrs: &[ast::Attribute], sess: &Session) -> Limit {
+    if let Some(attr) = krate_attrs
+        .iter()
+        .find(|attr| attr.has_name(sym::recursion_limit) && attr.value_str().is_none())
+    {
+        // This is here mainly to check for using a macro, such as
+        // #![recursion_limit = foo!()]. That is not supported since that
+        // would require expanding this while in the middle of expansion,
+        // which needs to know the limit before expanding. Otherwise,
+        // validation would normally be caught in AstValidator (via
+        // `check_builtin_attribute`), but by the time that runs the macro
+        // is expanded, and it doesn't give an error.
+        validate_attr::emit_fatal_malformed_builtin_attribute(
+            &sess.parse_sess,
+            attr,
+            sym::recursion_limit,
+        );
+    }
+    rustc_middle::middle::limits::get_recursion_limit(krate_attrs, sess)
+}