malloc: Remove __malloc_initialize_hook from the API [BZ #19564]

__malloc_initialize_hook is interposed by application code, so
the usual approach to define a compatibility symbol does not work.
This commit adds a new mechanism based on #pragma GCC poison in
<stdc-predef.h>.

1 files changed, 15 insertions, 1 deletions

diff --git a/malloc/malloc.c b/malloc/malloc.c
index 6f77d372a8..ac0f751593 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -491,6 +491,15 @@ void *(*__morecore)(ptrdiff_t) = __default_morecore;
 #define HAVE_MREMAP 0
 #endif
 
+/* We may need to support __malloc_initialize_hook for backwards
+   compatibility.  */
+
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24)
+# define HAVE_MALLOC_INIT_HOOK 1
+#else
+# define HAVE_MALLOC_INIT_HOOK 0
+#endif
+
 
 /*
   This version of malloc supports the standard SVID/XPG mallinfo
@@ -1841,7 +1850,12 @@ static void *realloc_hook_ini (void *ptr, size_t sz,
 static void *memalign_hook_ini (size_t alignment, size_t sz,
                                 const void *caller) __THROW;
 
-void weak_variable (*__malloc_initialize_hook) (void) = NULL;
+#if HAVE_MALLOC_INIT_HOOK
+void weak_variable (*old__malloc_initialize_hook) (void) = NULL;
+compat_symbol (libc, old__malloc_initialize_hook,
+	       old__malloc_initialize_hook, GLIBC_2_0);
+#endif
+
 void weak_variable (*__free_hook) (void *__ptr,
                                    const void *) = NULL;
 void *weak_variable (*__malloc_hook)