From 85e5cbd5ca94c4ad211628b2a6ef19493ceaee76 Mon Sep 17 00:00:00 2001
From: fuhsnn <66062782+fuhsnn@users.noreply.github.com>
Date: Fri, 12 Jul 2024 21:13:03 +0800
Subject: [PATCH] gh-121647: Define _Py_TYPEOF macro on more compilers

Extend the _Py_TYPEOF macro to more implementations of __typeof__ and standardized equivalents on C23 and C++11.
On MSVC, __typeof__ is enabled through _MSC_VER check; for others, an autoconf probe is implemented.
---
 Include/pyport.h |  9 +++++++--
 configure        | 30 ++++++++++++++++++++++++++++++
 configure.ac     | 13 +++++++++++++
 pyconfig.h.in    |  3 +++
 4 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/Include/pyport.h b/Include/pyport.h
index 2b6bd4c21110e5..9ed83765defc75 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -554,9 +554,14 @@ extern "C" {
 //
 // Example: _Py_TYPEOF(x) x_copy = (x);
 //
-// The macro is only defined if GCC or clang compiler is used.
-#if defined(__GNUC__) || defined(__clang__)
+// Defined if __typeof__ or its equivalents are available.
+#if defined(__GNUC__) || defined(__clang__) || defined(HAVE_TYPEOF) || \
+    (defined(_MSC_VER) && _MSC_VER >= 1939)
 #  define _Py_TYPEOF(expr) __typeof__(expr)
+#elif defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L
+#  define _Py_TYPEOF(expr) typeof(expr)
+#elif defined(__cplusplus) && __cplusplus >= 201103
+#  define _Py_TYPEOF(expr) decltype(expr)
 #endif
 
 
diff --git a/configure b/configure
index 19786f18e61726..1a6ba2b1204808 100755
--- a/configure
+++ b/configure
@@ -27661,6 +27661,36 @@ printf "%s\n" "#define HAVE_COMPUTED_GOTOS 1" >>confdefs.h
 
 esac
 
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CC supports __typeof__" >&5
+printf %s "checking whether $CC supports __typeof__... " >&6; }
+if test ${ac_cv_typeof+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int i;
+__typeof__(i) *p = &i;
+
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+  ac_cv_typeof=yes
+else $as_nop
+  ac_cv_typeof=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_typeof" >&5
+printf "%s\n" "$ac_cv_typeof" >&6; }
+if test "$ac_cv_typeof" = yes
+then
+
+printf "%s\n" "#define HAVE_TYPEOF 1" >>confdefs.h
+
+fi
+
 case $ac_sys_system in
 AIX*)
 
diff --git a/configure.ac b/configure.ac
index df146cc9cf0b75..6311aa60de3ca1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6983,6 +6983,19 @@ case "$ac_cv_computed_gotos" in yes*)
   [Define if the C compiler supports computed gotos.])
 esac
 
+AC_CACHE_CHECK([whether $CC supports __typeof__], [ac_cv_typeof],
+AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+int i;
+__typeof__(i) *p = &i;
+]])],
+[ac_cv_typeof=yes],
+[ac_cv_typeof=no]))
+if test "$ac_cv_typeof" = yes
+then
+  AC_DEFINE([HAVE_TYPEOF], [1],
+  [Define if the C compiler supports  __typeof__(expr)])
+fi
+
 case $ac_sys_system in
 AIX*)
   AC_DEFINE([HAVE_BROKEN_PIPE_BUF], [1],
diff --git a/pyconfig.h.in b/pyconfig.h.in
index 8fbba7ed3b949e..9d81b390cec0f3 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -1498,6 +1498,9 @@
 /* Define to 1 if you have the `ttyname' function. */
 #undef HAVE_TTYNAME
 
+/* Define if the C compiler supports __typeof__(expr) */
+#undef HAVE_TYPEOF
+
 /* Define to 1 if you don't have `tm_zone' but do have the external array
    `tzname'. */
 #undef HAVE_TZNAME