[gcc r17-4321] gccrs: Fix debug output of variance analysis to switch to substitutionref

[Arthur Cohen via Gcc-cvs]

https://gcc.gnu.org/g:83d9ebd601c11c3f976944f2f21037ae9e9e2081

commit r17-4321-g83d9ebd601c11c3f976944f2f21037ae9e9e2081
Author: Philip Herron <herron.phi...@googlemail.com>
Date:   Mon Aug 31 22:47:37 2026 +0100

    gccrs: Fix debug output of variance analysis to switch to substitutionref
    
    gcc/rust/ChangeLog:
    
            * typecheck/rust-tyty-variance-analysis.cc 
(GenericTyPerCrateCtx::debug_print_solutions):
            we can switch into a substitutionref base class to make this generic
    
    Signed-off-by: Philip Herron <herron.phi...@googlemail.com>

Diff:
---
 gcc/rust/typecheck/rust-tyty-variance-analysis.cc | 62 +++++++++++++----------
 1 file changed, 36 insertions(+), 26 deletions(-)

diff --git a/gcc/rust/typecheck/rust-tyty-variance-analysis.cc 
b/gcc/rust/typecheck/rust-tyty-variance-analysis.cc
index 6c6877ef9ecb..2b1a8b7db6f8 100644
--- a/gcc/rust/typecheck/rust-tyty-variance-analysis.cc
+++ b/gcc/rust/typecheck/rust-tyty-variance-analysis.cc
@@ -180,39 +180,49 @@ GenericTyPerCrateCtx::debug_print_solutions ()
       BaseType *ty = lookup_type (ref);
 
       std::string result = "\t";
+      SubstitutionRef *subst = nullptr;
 
-      if (auto adt = ty->try_as<ADTType> ())
+      switch (ty->get_kind ())
        {
-         result += adt->get_identifier ();
-         result += "<";
+       case TypeKind::ADT:
+         subst = static_cast<ADTType *> (ty);
+         break;
+       case TypeKind::FNDEF:
+         subst = static_cast<FnType *> (ty);
+         break;
+       case TypeKind::CLOSURE:
+         subst = static_cast<ClosureType *> (ty);
+         break;
+       case TypeKind::PROJECTION:
+         subst = static_cast<ProjectionType *> (ty);
+         break;
+       default:
+         rust_unreachable ();
+       }
 
-         size_t i = solution_index;
-         for (auto &region : adt->get_used_arguments ().get_regions ())
-           {
-             (void) region;
-             if (i > solution_index)
-               result += ", ";
-             result += solutions[i].as_string ();
-             i++;
-           }
-         for (auto &param : adt->get_substs ())
-           {
-             if (i > solution_index)
-               result += ", ";
-             result += param.get_type_representation ().as_string ();
-             result += "=";
-             result += solutions[i].as_string ();
-             i++;
-           }
+      result += ty->get_name ();
+      result += "<";
 
-         result += ">";
+      size_t i = solution_index;
+      for (auto &region : subst->get_used_arguments ().get_regions ())
+       {
+         (void) region;
+         if (i > solution_index)
+           result += ", ";
+         result += solutions[i].as_string ();
+         i++;
        }
-      else
+      for (auto &param : subst->get_substs ())
        {
-         rust_sorry_at (
-           ty->get_ref (),
-           "This is a compiler bug: Unhandled type in variance analysis");
+         if (i > solution_index)
+           result += ", ";
+         result += param.get_type_representation ().as_string ();
+         result += "=";
+         result += solutions[i].as_string ();
+         i++;
        }
+
+      result += ">";
       rust_debug ("%s", result.c_str ());
     }
 }