0001-WIP-Fix-AC_CHECK_DECLS-equivalent-in-meson.patch

From e12c5d224a195b893f79c470bc4f21de1585c808 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Tue, 1 Apr 2025 19:00:39 +0200
Subject: [PATCH] WIP: Fix AC_CHECK_DECLS equivalent in meson

---
 meson.build | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/meson.build b/meson.build
index 6932a0f00f7..ba7916d1493 100644
--- a/meson.build
+++ b/meson.build
@@ -2594,8 +2594,23 @@ foreach c : decl_checks
   args = c.get(2, {})
   varname = 'HAVE_DECL_' + func.underscorify().to_upper()
 
-  found = cc.has_header_symbol(header, func,
-    args: test_c_args, include_directories: postgres_inc,
+  found = cc.compiles('''
+#include <@0@>
+
+int main()
+{
+#ifndef @1@
+    (void) @1@;
+#endif
+
+return 0;
+}
+'''.format(header, func),
+    name: 'test whether @0@ is declared'.format(func),
+    # need to add cflags_warn to get at least
+    # -Werror=unguarded-availability-new if applicable
+    args: test_c_args + cflags_warn,
+    include_directories: postgres_inc,
     kwargs: args)
   cdata.set10(varname, found, description:
 '''Define to 1 if you have the declaration of `@0@', and to 0 if you
-- 
2.49.0