[PATCH 2/2] Use new symver function attribute to support LTO builds

The LTO support cannot work properly when there are versioned symbols
via asm statements, as those are not seen by the compiler. Use the new
function attributes if supported instead of the asm statements.

We need to move the SYMVER calls after the function definitions
otherwise it will reference symbols not yet seen.

Signed-off-by: Guillem Jover <guillem@hadrons.org>
Gbp-Pq: Name 0002-Use-new-symver-function-attribute-to-support-LTO-bui.patch

diff --git a/src/compat-0_1.c b/src/compat-0_1.c
index 722e107444f533ba7ef50338af5e7cd0a8c76c4f..ac40fccdd6898db0a42d7606a1e7ba0fbda18fdb 100644 (file)
--- a/src/compat-0_1.c
+++ b/src/compat-0_1.c
@@ -28,7 +28,6 @@
 
 
 /* ABI change.  Provide partial compatibility on this one for now. */
-SYMVER(compat0_1_io_cancel, io_cancel, 0.1);
 int compat0_1_io_cancel(io_context_t ctx, struct iocb *iocb)
 {
        struct io_event event;
@@ -36,8 +35,8 @@ int compat0_1_io_cancel(io_context_t ctx, struct iocb *iocb)
        /* FIXME: the old ABI would return the event on the completion queue */
        return io_cancel(ctx, iocb, &event);
 }
+SYMVER(compat0_1_io_cancel, io_cancel, 0.1);
 
-SYMVER(compat0_1_io_queue_wait, io_queue_wait, 0.1);
 int compat0_1_io_queue_wait(io_context_t ctx, struct timespec *when)
 {
        struct timespec timeout;
@@ -45,10 +44,10 @@ int compat0_1_io_queue_wait(io_context_t ctx, struct timespec *when)
                timeout = *when;
        return io_getevents(ctx, 0, 0, NULL, when ? &timeout : NULL);
 }
+SYMVER(compat0_1_io_queue_wait, io_queue_wait, 0.1);
 
 
 /* ABI change.  Provide backwards compatibility for this one. */
-SYMVER(compat0_1_io_getevents, io_getevents, 0.1);
 int compat0_1_io_getevents(io_context_t ctx, long nr,
                       struct io_event *events,
                       const struct timespec *const_timeout)
@@ -59,4 +58,4 @@ int compat0_1_io_getevents(io_context_t ctx, long nr,
        return io_getevents(ctx, 1, nr, events,
                        const_timeout ? &timeout : NULL);
 }
-
+SYMVER(compat0_1_io_getevents, io_getevents, 0.1);

diff --git a/src/syscall.h b/src/syscall.h
index 31d440df3a277087328c4ecbf61c36e61d70639f..bbc88e42430f901f067d5dc581c42b4c61c78332 100644 (file)
--- a/src/syscall.h
+++ b/src/syscall.h
@@ -2,14 +2,27 @@
 #include <unistd.h>
 #include <errno.h>
 
+#ifndef __has_attribute
+#define __has_attribute(x) 0
+#endif
+
 #define _SYMSTR(str)   #str
 #define SYMSTR(str)    _SYMSTR(str)
 
+#if __has_attribute(__symver__)
+#define SYMVER(compat_sym, orig_sym, ver_sym)  \
+       extern __typeof(compat_sym) compat_sym \
+         __attribute__((__symver__(SYMSTR(orig_sym) "@LIBAIO_" SYMSTR(ver_sym))))
+#define DEFSYMVER(compat_sym, orig_sym, ver_sym)       \
+       extern __typeof(compat_sym) compat_sym \
+         __attribute__((__symver__(SYMSTR(orig_sym) "@@LIBAIO_" SYMSTR(ver_sym))))
+#else
 #define SYMVER(compat_sym, orig_sym, ver_sym)  \
        __asm__(".symver " SYMSTR(compat_sym) "," SYMSTR(orig_sym) "@LIBAIO_" SYMSTR(ver_sym))
 
 #define DEFSYMVER(compat_sym, orig_sym, ver_sym)       \
        __asm__(".symver " SYMSTR(compat_sym) "," SYMSTR(orig_sym) "@@LIBAIO_" SYMSTR(ver_sym))
+#endif
 
 #if defined(__i386__)
 #include "syscall-i386.h"