From 23e72941ff560f75e398975daee28f3e7db9b37c Mon Sep 17 00:00:00 2001
From: Daniele Varrazzo <daniele.varrazzo@gmail.com>
Date: Fri, 9 May 2025 15:00:34 +0200
Subject: [PATCH] fix: fix building with PostgreSQL v18 libpq

Use 64 bits support from C99 types.

Fix #1082
---
 docs/news.rst                        |  1 +
 psycopg_c/psycopg_c/types/numutils.c | 38 +++++++---------------------
 2 files changed, 10 insertions(+), 29 deletions(-)

diff --git a/docs/news.rst b/docs/news.rst
index e253078ff..151e8114d 100644
--- a/docs/news.rst
+++ b/docs/news.rst
@@ -26,6 +26,7 @@ Psycopg 3.2.8 (unreleased)
   returns `None` (:ticket:`#1073`).
 - Fix `ConnectionInfo.port` when the port is specified as an empty string
   (:ticket:`#1078`).
+- Add support for PostgreSQL 18 libpq (:ticket:`#1082`).
 
 
 Current release
diff --git a/psycopg_c/psycopg_c/types/numutils.c b/psycopg_c/psycopg_c/types/numutils.c
index 4be7108bb..2be6b3973 100644
--- a/psycopg_c/psycopg_c/types/numutils.c
+++ b/psycopg_c/psycopg_c/types/numutils.c
@@ -15,32 +15,10 @@
 /*
  * 64-bit integers
  */
-#ifdef HAVE_LONG_INT_64
-/* Plain "long int" fits, use it */
-
-# ifndef HAVE_INT64
-typedef long int int64;
-# endif
-# ifndef HAVE_UINT64
-typedef unsigned long int uint64;
-# endif
-# define INT64CONST(x)  (x##L)
-# define UINT64CONST(x) (x##UL)
-#elif defined(HAVE_LONG_LONG_INT_64)
-/* We have working support for "long long int", use that */
-
-# ifndef HAVE_INT64
-typedef long long int int64;
-# endif
-# ifndef HAVE_UINT64
-typedef unsigned long long int uint64;
-# endif
-# define INT64CONST(x)  (x##LL)
-# define UINT64CONST(x) (x##ULL)
-#else
-/* neither HAVE_LONG_INT_64 nor HAVE_LONG_LONG_INT_64 */
-# error must have a working 64-bit integer datatype
-#endif
+typedef uint64_t uint64;
+typedef int64_t int64;
+
+#define UINT64CONST(x) UINT64_C(x)
 
 
 #ifndef HAVE__BUILTIN_CLZ
@@ -90,13 +68,15 @@ static inline int
 pg_leftmost_one_pos64(uint64_t word)
 {
 #ifdef HAVE__BUILTIN_CLZ
-#if defined(HAVE_LONG_INT_64)
+
+#if SIZEOF_LONG == 8
 	return 63 - __builtin_clzl(word);
-#elif defined(HAVE_LONG_LONG_INT_64)
+#elif SIZEOF_LONG_LONG == 8
 	return 63 - __builtin_clzll(word);
 #else
-#error must have a working 64-bit integer datatype
+#error "cannot find integer type of the same size as uint64_t"
 #endif
+
 #else							/* !HAVE__BUILTIN_CLZ */
 	int			shift = 64 - 8;
 
-- 
2.47.3