https://gcc.gnu.org/g:f707c093dee0468a3ef837a6c40afcf4c7fa7e46
commit r16-3413-gf707c093dee0468a3ef837a6c40afcf4c7fa7e46
Author: Jakub Jelinek <ja...@redhat.com>
Date: Wed Aug 27 14:00:51 2025 +0200
c++: Fix up cpp_warn on __STDCPP_FLOAT*_T__ [PR121520]
I got the cpp_warn on __STDCPP_FLOAT*_T__ if we aren't predefining those
wrong, so e.g. on powerpc64le we don't diagnose #undef __STDCPP_FLOAT16_T__.
I've added it as else if on the
if (c_dialect_cxx () && cxx_dialect > cxx20 && !floatn_nx_types[i].extended)
condition, which means cpp_warn is called in case a target supports some
extended type like _Float32x, cpp_warn is called on __STDCPP_FLOAT32_T__
(where when it supported _Float32 as well it did cpp_define_warn
(pfile, "__STDCPP_FLOAT32_T__=1") earlier).
On targets where the types aren't supported the earlier
if (FLOATN_NX_TYPE_NODE (i) == NULL_TREE) continue;
path is taken.
This patch fixes it to cpp_warn on the non-extended types for C++23
if the target doesn't support them and cpp_define_warn as before if it does.
2025-08-27 Jakub Jelinek <ja...@redhat.com>
PR target/121520
* c-cppbuiltin.cc (c_cpp_builtins): Properly call cpp_warn
for __STDCPP_FLOAT<NN>_T__ if FLOATN_NX_TYPE_NODE (i) is NULL
for C++23 for non-extended types and don't call cpp_warn for
extended types.
Diff:
---
gcc/c-family/c-cppbuiltin.cc | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/gcc/c-family/c-cppbuiltin.cc b/gcc/c-family/c-cppbuiltin.cc
index fe80e1f80fff..6b22f9e60b14 100644
--- a/gcc/c-family/c-cppbuiltin.cc
+++ b/gcc/c-family/c-cppbuiltin.cc
@@ -1327,22 +1327,22 @@ c_cpp_builtins (cpp_reader *pfile)
for (int i = 0; i < NUM_FLOATN_NX_TYPES; i++)
{
- if (FLOATN_NX_TYPE_NODE (i) == NULL_TREE)
- continue;
if (c_dialect_cxx ()
&& cxx_dialect > cxx20
&& !floatn_nx_types[i].extended)
{
char name[sizeof ("__STDCPP_FLOAT128_T__=1")];
+ if (FLOATN_NX_TYPE_NODE (i) == NULL_TREE)
+ {
+ sprintf (name, "__STDCPP_FLOAT%d_T__", floatn_nx_types[i].n);
+ cpp_warn (pfile, name);
+ continue;
+ }
sprintf (name, "__STDCPP_FLOAT%d_T__=1", floatn_nx_types[i].n);
cpp_define_warn (pfile, name);
}
- else if (cxx_dialect >= cxx23)
- {
- char name[sizeof ("__STDCPP_FLOAT128_T__")];
- sprintf (name, "__STDCPP_FLOAT%d_T__", floatn_nx_types[i].n);
- cpp_warn (pfile, name);
- }
+ else if (FLOATN_NX_TYPE_NODE (i) == NULL_TREE)
+ continue;
char prefix[20], csuffix[20];
sprintf (prefix, "FLT%d%s", floatn_nx_types[i].n,
floatn_nx_types[i].extended ? "X" : "");
