bug#18368: HYBRID_MALLOC broke AIX build

bug#18368: HYBRID_MALLOC broke AIX build

[Paul Eggert]

The trunk's recent HYBRID_MALLOC changes broke the build on AIX.  Here 
are the first couple of compile-time diagnostics:

xlc -c  -Demacs  -I. -I. -I../lib -I../lib -g3 -O  gmalloc.c
"/usr/include/unistd.h", line 201.17: 1506-343 (S) Redeclaration of 
lseek64 differs from previous declaration on line 199 of 
"/usr/include/unistd.h".
"/usr/include/unistd.h", line 201.17: 1506-050 (I) Return type "long 
long" in redeclaration is not compatible with the previous return type 
"long".

The culprit is this part of gmalloc.c:

/* If HYBRID_MALLOC is defined in config.h, then conf_post.h #defines
    malloc and friends as macros before including stdlib.h.  In this
    file we will need the prototypes for the system malloc, so we must
    include stdlib.h before config.h.  And we have to do this
    unconditionally, since HYBRID_MALLOC hasn't been defined yet.  */
#include <stdlib.h>

#include <config.h>


This doesn't work, as <config.h> must come first for various reasons; I 
suspect the AIX breakage is just the tip of the iceberg.

One possible fix is to declare the system malloc directly, if 
HYBRID_MALLOC is defined.  Another one, which might be safer, is to 
modify config.h to capture the system malloc before it's redefined.

Since AIX does not define HYBRID_MALLOC, I have temporarily worked 
around the problem on my AIX host by using this in gmalloc.c:

#ifdef HYBRID_MALLOC
#include <stdlib.h>
#endif

#include <config.h>

#include <stdlib.h>

but I suspect this is not the right way to fix the problems on platforms 
that need HYBRID_MALLOC but have AIX-like problems with redefinitions.

bug#18368: HYBRID_MALLOC broke AIX build

[Ken Brown]

On 8/30/2014 6:50 PM, Paul Eggert wrote:
> The trunk's recent HYBRID_MALLOC changes broke the build on AIX.

How's this:

=== modified file 'src/gmalloc.c'
--- src/gmalloc.c       2014-08-28 14:48:02 +0000
+++ src/gmalloc.c       2014-08-31 01:29:41 +0000
@@ -19,13 +19,6 @@
     The author may be reached (Email) at the address mike@ai.mit.edu,
     or (US mail) as Mike Haertel c/o Free Software Foundation.  */

-/* If HYBRID_MALLOC is defined in config.h, then conf_post.h #defines
-   malloc and friends as macros before including stdlib.h.  In this
-   file we will need the prototypes for the system malloc, so we must
-   include stdlib.h before config.h.  And we have to do this
-   unconditionally, since HYBRID_MALLOC hasn't been defined yet.  */
-#include <stdlib.h>
-
  #include <config.h>

  #if defined HAVE_PTHREAD && !defined HYBRID_MALLOC
@@ -1725,6 +1718,17 @@
  #undef aligned_alloc
  #undef free

+/* Declare system malloc and friends.  */
+extern void *malloc (size_t size);
+extern void *realloc (void *ptr, size_t size);
+extern void *calloc (size_t nmemb, size_t size);
+extern void free (void *ptr);
+#ifdef HAVE_ALIGNED_ALLOC
+extern void *aligned_alloc (size_t alignment, size_t size);
+#elif defined HAVE_POSIX_MEMALIGN
+extern int posix_memalign (void **memptr, size_t alignment, size_t size);
+#endif
+
  /* See the comments near the beginning of this file for explanations
     of the following functions. */

bug#18368: HYBRID_MALLOC broke AIX build

[Paul Eggert]

Ken Brown wrote:
> How's this:

Thanks, I verified that that patch works on AIX.

bug#18368: HYBRID_MALLOC broke AIX build

[Ken Brown]

Version: 24.5

On 8/30/2014 10:21 PM, Paul Eggert wrote:
> Thanks, I verified that that patch works on AIX.

I've installed the patch in the trunk as bzr revision 117787.

Ken