[gcc r14-4829] objc++: type/expr tsubst conflation [PR111920]

[gcc r14-4829] objc++: type/expr tsubst conflation [PR111920]

[Patrick Palka]

https://gcc.gnu.org/g:80ddcb9c8f9b5a387f379e1db39bc6f3680bd52f

commit r14-4829-g80ddcb9c8f9b5a387f379e1db39bc6f3680bd52f
Author: Patrick Palka <ppalka@redhat.com>
Date:   Sun Oct 22 16:13:33 2023 -0400

    objc++: type/expr tsubst conflation [PR111920]
    
    After r14-4796-g3e3d73ed5e85e7, tsubst_copy_and_build (now named
    tsubst_expr) no longer dispatches to tsubst for type trees, and
    callers have to do it themselves if appropriate.  This patch makes
    some overlooked adjustments to Objective-C++-specific code paths.
    
            PR objc++/111920
    
    gcc/cp/ChangeLog:
    
            * pt.cc (tsubst_expr) <case AT_ENCODE_EXPR>: Use tsubst instead
            of tsubst_expr.
    
    gcc/objcp/ChangeLog:
    
            * objcp-lang.cc (objcp_tsubst_expr) <case CLASS_REFERENCE_EXPR>:
            Use tsubst instead of tsubst_expr for type operands.

Diff:
---
 gcc/cp/pt.cc            |  2 +-
 gcc/objcp/objcp-lang.cc | 10 ++++++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 210c6cb9e4d3..1c1c93131180 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -20261,7 +20261,7 @@ tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 	op1 = TREE_OPERAND (t, 0);
 	++cp_unevaluated_operand;
 	++c_inhibit_evaluation_warnings;
-	op1 = tsubst_expr (op1, args, complain, in_decl);
+	op1 = tsubst (op1, args, complain, in_decl);
 	--cp_unevaluated_operand;
 	--c_inhibit_evaluation_warnings;
 	RETURN (objc_build_encode_expr (op1));
diff --git a/gcc/objcp/objcp-lang.cc b/gcc/objcp/objcp-lang.cc
index 5b04cd66290f..ee39aece8484 100644
--- a/gcc/objcp/objcp-lang.cc
+++ b/gcc/objcp/objcp-lang.cc
@@ -66,8 +66,14 @@ objcp_tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 	 RECURSE (TREE_OPERAND (t, 2)), NULL);
 
     case CLASS_REFERENCE_EXPR:
-      return objc_get_class_reference
-	(RECURSE (TREE_OPERAND (t, 0)));
+      {
+	tree ident = TREE_OPERAND (t, 0);
+	if (TYPE_P (ident))
+	  ident = tsubst (ident, args, complain, in_decl);
+	else
+	  ident = RECURSE (ident);
+	return objc_get_class_reference (ident);
+      }
 
     default:
       break;