Fixed ptrdiff_t redefined static analysis warning on GCC. Failing ptrdiff_t detection...

  In file included from zlib-ng/zlib-ng.h:33,
                   from zlib-ng/zutil.h:38,
                   from zlib-ng/adler32.c:7:
  zlib-ng/zconf-ng.h:118:18: error: conflicting types for ‘ptrdiff_t’
    118 | typedef uint64_t ptrdiff_t;
        |                  ^~~~~~~~~
  In file included from zlib-ng/zutil.h:31,
                   from zlib-ng/adler32.c:7:
  stddef.h:143:26: note: previous declaration of ‘ptrdiff_t’ was here
    143 | typedef __PTRDIFF_TYPE__ ptrdiff_t;
        |                          ^~~~~~~~~

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ce103f6a7ccdcc47362c84c2bfe9fab6493d6da1..66139a14fc341aaeafad7d81fbd210a52e305c65 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -444,7 +444,7 @@ endif()
 #
 check_c_source_compiles(
     "#include <stddef.h>
-     int main() { ptrdiff_t *a; return 0; }"
+     int main() { ptrdiff_t *a; (void)a; return 0; }"
     HAVE_PTRDIFF_T
 )
 if(NOT HAVE_PTRDIFF_T)