[src/mpfr-impl.h] MPFR_GROUP_* macros / mpfr_group_t structure: when

MPFR_GROUP_STATIC_SIZE is 0 (for testing), use a flexible array member
(ISO C99) instead of a zero-length array (GNU extension, forbidden in
ISO C).
(merged changeset r13517 from the trunk)

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/branches/4.0@13518 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 14 insertions, 0 deletions

diff --git a/src/mpfr-impl.h b/src/mpfr-impl.h
index e2a2dd0d9..98e2d2325 100644
--- a/src/mpfr-impl.h
+++ b/src/mpfr-impl.h
@@ -2026,7 +2026,21 @@ __MPFR_DECLSPEC extern mpfr_prec_t mpfr_log_prec;
 struct mpfr_group_t {
   size_t     alloc;
   mp_limb_t *mant;
+#if MPFR_GROUP_STATIC_SIZE != 0
   mp_limb_t  tab[MPFR_GROUP_STATIC_SIZE];
+#else
+  /* In order to detect memory leaks when testing, MPFR_GROUP_STATIC_SIZE
+     can be set to 0, in which case tab will not be used. ISO C does not
+     support zero-length arrays[*], thus let's use a flexible array member
+     (which will be equivalent here). Note: this is new in C99, but this
+     is just used for testing.
+     [*] Zero-length arrays are a GNU extension:
+           https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
+         and as such an extension is forbidden in ISO C, it triggers an
+         error with -Werror=pedantic.
+  */
+  mp_limb_t  tab[];
+#endif
 };
 
 #define MPFR_GROUP_DECL(g) struct mpfr_group_t g