[gcc r12-7669] c++: further lookup_member simplification

[Patrick Palka]

https://gcc.gnu.org/g:5809bb4f78c9aae0f3be3c8d942b6af75ba23a74

commit r12-7669-g5809bb4f78c9aae0f3be3c8d942b6af75ba23a74
Author: Patrick Palka <ppalka@redhat.com>
Date:   Wed Mar 16 08:26:11 2022 -0400

    c++: further lookup_member simplification
    
    As a minor followup to r12-7656-gffe9c0a0d3564a, this condenses the
    handling of ambiguity and access w.r.t. the value of 'protect' so that
    the logic is more clear.
    
    gcc/cp/ChangeLog:
    
            * search.cc (lookup_member): Simplify by handling all values
            of protect together in the ambiguous case.  Don't modify protect.

Diff:
---
 gcc/cp/search.cc | 32 +++++++++++++-------------------
 1 file changed, 13 insertions(+), 19 deletions(-)

diff --git a/gcc/cp/search.cc b/gcc/cp/search.cc
index 85e3e7cb487..b86b3a24080 100644
--- a/gcc/cp/search.cc
+++ b/gcc/cp/search.cc
@@ -1168,27 +1168,21 @@ lookup_member (tree xbasetype, tree name, int protect, bool want_type,
   if (rval_binfo)
     type = BINFO_TYPE (rval_binfo);
 
-  /* If we are not interested in ambiguities, don't report them;
-     just return NULL_TREE.  */
-  if (!protect && lfi.ambiguous)
-    return NULL_TREE;
-
-  if (protect == 2)
-    {
-      if (lfi.ambiguous)
-	return lfi.ambiguous;
-      else
-	protect = 0;
-    }
-
-  if (protect == 1 && lfi.ambiguous)
+  if (lfi.ambiguous)
     {
-      if (complain & tf_error)
+      if (protect == 0)
+	return NULL_TREE;
+      else if (protect == 1)
 	{
-	  error ("request for member %qD is ambiguous", name);
-	  print_candidates (lfi.ambiguous);
+	  if (complain & tf_error)
+	    {
+	      error ("request for member %qD is ambiguous", name);
+	      print_candidates (lfi.ambiguous);
+	    }
+	  return error_mark_node;
 	}
-      return error_mark_node;
+      else if (protect == 2)
+	return lfi.ambiguous;
     }
 
   if (!rval)
@@ -1213,7 +1207,7 @@ lookup_member (tree xbasetype, tree name, int protect, bool want_type,
 
     only the first call to "f" is valid.  However, if the function is
     static, we can check.  */
-  if (protect && !really_overloaded_fn (rval))
+  if (protect == 1 && !really_overloaded_fn (rval))
     {
       tree decl = is_overloaded_fn (rval) ? get_first_fn (rval) : rval;
       decl = strip_using_decl (decl);