Commit ff7c8b21 (2021) to pacify -Wsuggest-attribute=pure with GCC 10.3
induces the code to be removed with clang 21,22 with -fno-inline.
I don't see the same code elimination on GCC 15,
but the the incorrect warning is still there.
(Note xalloc_die() is marked _Noreturn so GCC is wrong here).
You can see the difference using split(1).
Without -fno-inline it behaves as expected:
$ src/split --number=r/9223372036854775808
split: memory exhausted
and with the -fno-inline:
$ src/split --number=r/9223372036854775807
Segmentation fault (core dumped)
* lib/xmalloc.c (check_nonnull): Remove the "pure" attribute,
and suppress the incorrect GCC warning with pragmas.
---
lib/xmalloc.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/lib/xmalloc.c b/lib/xmalloc.c
index b67cd4c223..b889004381 100644
--- a/lib/xmalloc.c
+++ b/lib/xmalloc.c
@@ -27,13 +27,24 @@
#include <stdint.h>
#include <string.h>
-static void * _GL_ATTRIBUTE_PURE
+/* Suppress GCC's -Wsuggest-attribute=pure
+ incorrectly generated by GCC versions up to at least GCC 15.1.
+ Note with attribute pure, `clang -fno-inline` would eliminate
+ calls to check_nonnull(). */
+#if _GL_GNUC_PREREQ (4, 7)
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wsuggest-attribute=pure"
+#endif
+static void *
check_nonnull (void *p)
{
if (!p)
xalloc_die ();
return p;
}
+#if _GL_GNUC_PREREQ (4, 7)
+# pragma GCC diagnostic pop
+#endif
/* Allocate S bytes of memory dynamically, with error checking. */
--
2.52.0
