On outer attr not found, avoid knock-down errors

When we encounter code like

```rust
#![non_existent]

#[derive(Clone)]
struct S;

fn main() {
    S.clone();
}
```

we avoid emitting errors about the `derive` (which isn't early resolved
as normal, but *has* a later resolution) and stop the compiler from
advancing to later stages, to avoid knock down errors from the `derive`
not being evaluated. Recovering these would be possible, but would
produce incorrect errors in the cases where had the outer attribute been
present it would have modified the behavior/evaluation of the `derive`
attributes.

Fix #118455.

Author: estebank

compiler/rustc_resolve/src/diagnostics.rs

@@ -1039,6 +1039,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                             if let Ok((Some(ext), _)) = this.resolve_macro_path(
                                 derive,
                                 Some(MacroKind::Derive),
+                                false,
                                 parent_scope,
                                 false,
                                 false,

compiler/rustc_resolve/src/ident.rs

@@ -443,6 +443,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                             match this.resolve_macro_path(
                                 derive,
                                 Some(MacroKind::Derive),
+                                false,
                                 parent_scope,
                                 true,
                                 force,

compiler/rustc_resolve/src/late.rs

@@ -3869,7 +3869,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             let path_seg = |seg: &Segment| PathSegment::from_ident(seg.ident);
             let path = Path { segments: path.iter().map(path_seg).collect(), span, tokens: None };
             if let Ok((_, res)) =
-                self.r.resolve_macro_path(&path, None, &self.parent_scope, false, false)
+                self.r.resolve_macro_path(&path, None, false, &self.parent_scope, false, false)
             {
                 return Ok(Some(PartialRes::new(res)));
             }

compiler/rustc_resolve/src/lib.rs

@@ -1047,7 +1047,7 @@ pub struct Resolver<'a, 'tcx> {
     proc_macro_stubs: FxHashSet<LocalDefId>,
     /// Traces collected during macro resolution and validated when it's complete.
     single_segment_macro_resolutions:
-        Vec<(Ident, MacroKind, ParentScope<'a>, Option<NameBinding<'a>>)>,
+        Vec<(Ident, MacroKind, bool, ParentScope<'a>, Option<NameBinding<'a>>)>,
     multi_segment_macro_resolutions:
         Vec<(Vec<Segment>, Span, MacroKind, ParentScope<'a>, Option<Res>)>,
     builtin_attrs: Vec<(Ident, ParentScope<'a>)>,

compiler/rustc_resolve/src/macros.rs

@@ -15,7 +15,7 @@ use rustc_ast_pretty::pprust;
 use rustc_attr::StabilityLevel;
 use rustc_data_structures::intern::Interned;
 use rustc_data_structures::sync::Lrc;
-use rustc_errors::{struct_span_err, Applicability};
+use rustc_errors::{struct_span_err, Applicability, FatalError};
 use rustc_expand::base::{Annotatable, DeriveResolutions, Indeterminate, ResolverExpand};
 use rustc_expand::base::{SyntaxExtension, SyntaxExtensionKind};
 use rustc_expand::compile_declarative_macro;
@@ -373,6 +373,7 @@ impl<'a, 'tcx> ResolverExpand for Resolver<'a, 'tcx> {
                     match self.resolve_macro_path(
                         path,
                         Some(MacroKind::Derive),
+                        false,
                         &parent_scope,
                         true,
                         force,
@@ -504,8 +505,14 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         force: bool,
         soft_custom_inner_attributes_gate: bool,
     ) -> Result<(Lrc<SyntaxExtension>, Res), Indeterminate> {
-        let (ext, res) = match self.resolve_macro_path(path, Some(kind), parent_scope, true, force)
-        {
+        let (ext, res) = match self.resolve_macro_path(
+            path,
+            Some(kind),
+            inner_attr,
+            parent_scope,
+            true,
+            force,
+        ) {
             Ok((Some(ext), res)) => (ext, res),
             Ok((None, res)) => (self.dummy_ext(kind), res),
             Err(Determinacy::Determined) => (self.dummy_ext(kind), Res::Err),
@@ -627,6 +634,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         &mut self,
         path: &ast::Path,
         kind: Option<MacroKind>,
+        inner_attr: bool,
         parent_scope: &ParentScope<'a>,
         trace: bool,
         force: bool,
@@ -685,6 +693,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 self.single_segment_macro_resolutions.push((
                     path[0].ident,
                     kind,
+                    inner_attr,
                     *parent_scope,
                     binding.ok(),
                 ));
@@ -794,7 +803,9 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         }
 
         let macro_resolutions = mem::take(&mut self.single_segment_macro_resolutions);
-        for (ident, kind, parent_scope, initial_binding) in macro_resolutions {
+        let mut has_reported_inner_attr_error = false;
+        let mut raise_fatal_error = false;
+        for (ident, kind, inner_attr, parent_scope, initial_binding) in macro_resolutions {
             match self.early_resolve_ident_in_lexical_scope(
                 ident,
                 ScopeSet::Macro(kind),
@@ -810,7 +821,17 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                     });
                     let res = binding.res();
                     let seg = Segment::from_ident(ident);
-                    check_consistency(self, &[seg], ident.span, kind, initial_res, res);
+                    if has_reported_inner_attr_error
+                        && let Res::Def(DefKind::Macro(MacroKind::Attr), _) = res
+                        && let None = initial_res
+                    {
+                        // Do not emit an indeterminate resolution and later errors when an outer
+                        // attribute wasn't found, as this can be knock down effects. #118455
+                        raise_fatal_error = true;
+                    } else {
+                        let res = binding.res();
+                        check_consistency(self, &[seg], ident.span, kind, initial_res, res);
+                    };
                     if res == Res::NonMacroAttr(NonMacroAttrKind::DeriveHelperCompat) {
                         let node_id = self
                             .invocation_parents
@@ -825,7 +846,10 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                         );
                     }
                 }
-                Err(..) => {
+                Err(_) => {
+                    if inner_attr {
+                        has_reported_inner_attr_error = true;
+                    }
                     let expected = kind.descr_expected();
 
                     let mut err = self.tcx.sess.create_err(CannotFindIdentInThisScope {
@@ -851,6 +875,16 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 None,
             );
         }
+
+        if raise_fatal_error {
+            // When we encounter an inner attribute failure, and subsequent successful macro
+            // resolutions following early resolution failures. This is so when an outer attribute
+            // isn't found, and we encounter `derive` attributes, we won't raise errors caused by
+            // any code that relies on those derives having been evaluated. We don't attempt to
+            // recover because the behavior of those derives could have been modified by the outer
+            // attribute, causing *other* errors, so it is safest to just stop early instead.
+            FatalError.raise();
+        }
     }
 
     fn check_stability_and_deprecation(

tests/ui/proc-macro/derive-helper-legacy-spurious.rs

@@ -5,8 +5,10 @@
 #[macro_use]
 extern crate test_macros;
 
-#[derive(Empty)] //~ ERROR cannot determine resolution for the attribute macro `derive`
+#[derive(Empty, Clone)] // no error emitted here
 #[empty_helper] //~ ERROR cannot find attribute `empty_helper` in this scope
 struct Foo {}
 
-fn main() {}
+fn main() {
+    let _ = Foo.clone(); // no error emitted here
+}

tests/ui/proc-macro/derive-helper-legacy-spurious.stderr

@@ -4,19 +4,11 @@ error: cannot find attribute `dummy` in this scope
 LL | #![dummy]
    |    ^^^^^
 
-error: cannot determine resolution for the attribute macro `derive`
-  --> $DIR/derive-helper-legacy-spurious.rs:8:3
-   |
-LL | #[derive(Empty)]
-   |   ^^^^^^
-   |
-   = note: import resolution is stuck, try simplifying macro imports
-
 error: cannot find attribute `empty_helper` in this scope
   --> $DIR/derive-helper-legacy-spurious.rs:9:3
    |
 LL | #[empty_helper]
    |   ^^^^^^^^^^^^
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors