[PATCH] stdbit: don’t assume -DHAVE_CONFIG_H

[Paul Eggert]

This is needed for diffutils, which doesn’t define HAVE_CONFIG_H.
There needs to be some way for a test shared with glibc to discover
whether it should use the Gnulib or the glibc testing framework,
and I guess this is it.
* modules/stdbit-tests (GNULIB_TEST_STDBIT): Define.
* tests/tst-stdbit.h: Use GNULIB_TEST_STDBIT, not HAVE_CONFIG_H.
---
 ChangeLog            | 10 ++++++++++
 modules/stdbit-tests |  2 ++
 tests/tst-stdbit.h   |  6 +++---
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6154ef2bc8..3e5df0d22d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2024-05-11  Paul Eggert  <eggert@cs.ucla.edu>
+
+       stdbit: don’t assume -DHAVE_CONFIG_H
+       This is needed for diffutils, which doesn’t define HAVE_CONFIG_H.
+       There needs to be some way for a test shared with glibc to discover
+       whether it should use the Gnulib or the glibc testing framework,
+       and I guess this is it.
+       * modules/stdbit-tests (GNULIB_TEST_STDBIT): Define.
+       * tests/tst-stdbit.h: Use GNULIB_TEST_STDBIT, not HAVE_CONFIG_H.
+
 2024-05-11  Collin Funk  <collin.funk1@gmail.com>
 
        gnulib-tool.py: Filter out dependencies that cannot be found.
diff --git a/modules/stdbit-tests b/modules/stdbit-tests
index 4ef358aca9..a5832c84f2 100644
--- a/modules/stdbit-tests
+++ b/modules/stdbit-tests
@@ -23,6 +23,8 @@ libc-config
 stdint
 
 configure.ac:
+AC_DEFINE([GNULIB_TEST_STDBIT], [1],
+  [Define to 1 so that stdbit tests use the Gnulib framework, not glibc's.])
 
 Makefile.am:
 TESTS += \
diff --git a/tests/tst-stdbit.h b/tests/tst-stdbit.h
index b40d7447bf..0a0ab6b66c 100644
--- a/tests/tst-stdbit.h
+++ b/tests/tst-stdbit.h
@@ -19,14 +19,14 @@
 #ifndef _TST_STDBIT_H
 #define _TST_STDBIT_H
 
-#if HAVE_CONFIG_H
+#if GNULIB_TEST_STDBIT
 # include <libc-config.h>
 #endif
 
 #include <stdbit.h>
 #include <stdbool.h>
 
-#if !HAVE_CONFIG_H
+#if !GNULIB_TEST_STDBIT
 # include <array_length.h>
 # include <support/check.h>
 #else
@@ -46,7 +46,7 @@ struct stdbit_test
   uint64_t res_8, res_16, res_32, res_64;
 };
 
-#if !HAVE_CONFIG_H
+#if !GNULIB_TEST_STDBIT
 # define TEST_TYPE(EXPR, TYPE)                                         \
   _Static_assert (_Generic ((EXPR), TYPE: 1, default: 0), "bad type")
 #elif ((defined __GNUC__ && 2 <= __GNUC__) \
-- 
2.40.1