[gcc r14-7680] gccrs: fix unsafe lookup at zero index

[Arthur Cohen]

https://gcc.gnu.org/g:946af759bdc029c1bbd3d6349ad5f80098bc30e3

commit r14-7680-g946af759bdc029c1bbd3d6349ad5f80098bc30e3
Author: Philip Herron <herron.philip@googlemail.com>
Date:   Tue Jun 20 10:39:54 2023 +0100

    gccrs: fix unsafe lookup at zero index
    
    Using lookup_predciate by DefId is the safe way to get the relevant
    predicate.
    
    Addresses #1893
    
    gcc/rust/ChangeLog:
    
            * typecheck/rust-hir-trait-resolve.cc: use lookup_predicate (DefID)
            * typecheck/rust-hir-type-check-path.cc (TypeCheckExpr::resolve_segments): fix formatting
    
    Signed-off-by: Philip Herron <herron.philip@googlemail.com>

Diff:
---
 gcc/rust/typecheck/rust-hir-trait-resolve.cc   | 8 +++-----
 gcc/rust/typecheck/rust-hir-type-check-path.cc | 4 +---
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/gcc/rust/typecheck/rust-hir-trait-resolve.cc b/gcc/rust/typecheck/rust-hir-trait-resolve.cc
index 7c6ce4c7a2d..099c6729483 100644
--- a/gcc/rust/typecheck/rust-hir-trait-resolve.cc
+++ b/gcc/rust/typecheck/rust-hir-trait-resolve.cc
@@ -513,11 +513,9 @@ AssociatedImplTrait::setup_associated_types (
 	? SubstMapperInternal::Resolve (associated_self, infer_arguments)
 	: associated_self;
 
-  // FIXME this needs to do a lookup for the trait-reference DefId instead of
-  // assuming its the first one in the list
-  rust_assert (associated_self->num_specified_bounds () > 0);
-  TyTy::TypeBoundPredicate &impl_predicate
-    = associated_self->get_specified_bounds ().at (0);
+  const TyTy::TypeBoundPredicate &impl_predicate
+    = associated_self->lookup_predicate (bound.get_id ());
+  rust_assert (!impl_predicate.is_error ());
 
   // infer the arguments on the predicate
   std::vector<TyTy::BaseType *> impl_trait_predicate_args;
diff --git a/gcc/rust/typecheck/rust-hir-type-check-path.cc b/gcc/rust/typecheck/rust-hir-type-check-path.cc
index 6ae58cea631..4bac75a63d9 100644
--- a/gcc/rust/typecheck/rust-hir-type-check-path.cc
+++ b/gcc/rust/typecheck/rust-hir-type-check-path.cc
@@ -427,9 +427,7 @@ TypeCheckExpr::resolve_segments (NodeId root_resolved_node_id,
 				     seg.get_locus ());
 	  bool ok = prev_segment->get_kind () != TyTy::TypeKind::ERROR;
 	  if (!ok)
-	    {
-	      return;
-	    }
+	    return;
 
 	  if (found_impl_trait)
 	    {