From f7f9401cc842824bccc3c79873d6e9f9dfe92997 Mon Sep 17 00:00:00 2001
From: Ilija Tovilo <ilija.tovilo@me.com>
Date: Thu, 9 Nov 2023 20:44:30 +0100
Subject: [PATCH] Disable -fsanitize=function on Clang 17

Closes GH-12642
---
 configure.ac | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/configure.ac b/configure.ac
index 0c5304b9e48..91cb9e2fe4c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1534,6 +1534,23 @@ if test "$PHP_UNDEFINED_SANITIZER" = "yes"; then
   AX_CHECK_COMPILE_FLAG([-fsanitize=undefined], [
     CFLAGS="$CFLAGS -fsanitize=undefined"
     CXXFLAGS="$CXXFLAGS -fsanitize=undefined"
+
+    dnl Clang 17 adds stricter function pointer compatibility checks where pointer args cannot be
+    dnl cast to void*. In that case, set -fno-sanitize=function.
+    OLD_CFLAGS="$CFLAGS"
+    CFLAGS="$CFLAGS -fno-sanitize-recover=undefined"
+    AC_RUN_IFELSE([AC_LANG_SOURCE([[
+void foo(char *string) {}
+int main(void) {
+  void (*f)(void *) = (void (*)(void *))foo;
+  f("foo");
+}
+    ]])],,[ubsan_needs_no_function=yes],)
+    CFLAGS="$OLD_CFLAGS"
+    if test "$ubsan_needs_no_function" = yes; then
+      CFLAGS="$CFLAGS -fno-sanitize=function"
+      CXXFLAGS="$CFLAGS -fno-sanitize=function"
+    fi
   ], [AC_MSG_ERROR([UndefinedBehaviorSanitizer is not available])])
 fi