[gcc r13-6643] c++: handle _FloatNN redeclaration like bool [PR107128]

[Jason Merrill <jason@gcc.gnu.org>]

https://gcc.gnu.org/g:538a0d0f29b12cff05681b6de2e0a3d7b33f3ef0

commit r13-6643-g538a0d0f29b12cff05681b6de2e0a3d7b33f3ef0
Author: Jason Merrill <jason@redhat.com>
Date:   Mon Mar 13 14:06:11 2023 -0400

    c++: handle _FloatNN redeclaration like bool [PR107128]
    
    It's been inconvenient to compile testcases preprocessed with GCC 12 or
    earlier because they break on
    
      typedef __float128 _Float128;
    
    We already had code for handling this with bool and wchar_t, it just needs
    to be extended to _FloatNN as well.
    
            PR c++/107128
    
    gcc/cp/ChangeLog:
    
            * parser.cc (cp_parser_set_decl_spec_type): Use
            redefined_builtin_type for extended_float_type_p.
    
    gcc/testsuite/ChangeLog:
    
            * g++.dg/warn/pragma-system_header6.h: New test.
            * g++.dg/warn/pragma-system_header6.C: New test.

Diff:
---
 gcc/testsuite/g++.dg/warn/pragma-system_header6.h | 3 +++
 gcc/cp/parser.cc                                  | 2 ++
 gcc/testsuite/g++.dg/warn/pragma-system_header6.C | 1 +
 3 files changed, 6 insertions(+)

diff --git a/gcc/testsuite/g++.dg/warn/pragma-system_header6.h b/gcc/testsuite/g++.dg/warn/pragma-system_header6.h
new file mode 100644
index 00000000000..989ccd8795a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/pragma-system_header6.h
@@ -0,0 +1,3 @@
+#pragma GCC system_header
+
+typedef float _Float32;
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index 533041946c0..a277003ea58 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -33452,10 +33452,12 @@ cp_parser_set_decl_spec_type (cp_decl_specifier_seq *decl_specs,
      C++-safe.  */
   if (decl_spec_seq_has_spec_p (decl_specs, ds_typedef)
       && !type_definition_p
+      && TYPE_P (type_spec)
       && (type_spec == boolean_type_node
 	  || type_spec == char8_type_node
 	  || type_spec == char16_type_node
 	  || type_spec == char32_type_node
+	  || extended_float_type_p (type_spec)
 	  || type_spec == wchar_type_node)
       && (decl_specs->type
 	  || decl_spec_seq_has_spec_p (decl_specs, ds_long)
diff --git a/gcc/testsuite/g++.dg/warn/pragma-system_header6.C b/gcc/testsuite/g++.dg/warn/pragma-system_header6.C
new file mode 100644
index 00000000000..924e4522cf0
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/pragma-system_header6.C
@@ -0,0 +1 @@
+#include "pragma-system_header6.h"