Compilation fails on Snow Leopard / MacPorts 2.1.3 / gcc 4.2.1

[BjoKaSH]

Compilation fails in dsl_scan.c and zio.c when trying to inline some function marked as "always inline":

zio.c: In function ‘zio_ready’:
zio.c:1250: error: ‘always_inline’ function could not be inlined in call to ‘__zio_execute’: function not considered for inlining
zio.c:537: error: called from here

dsl_scan.c: In function ‘dsl_scan_visitbp’:
dsl_scan.c:712: error: ‘always_inline’ function could not be inlined in call to ‘dsl_scan_visitdnode’: function not considered for inlining
dsl_scan.c:668: error: called from here
dsl_scan.c:712: error: ‘always_inline’ function could not be inlined in call to ‘dsl_scan_visitdnode’: function not considered for inlining
dsl_scan.c:686: error: called from here
dsl_scan.c:712: error: ‘always_inline’ function could not be inlined in call to ‘dsl_scan_visitdnode’: function not considered for inlining
dsl_scan.c:696: error: called from here
dsl_scan.c:712: error: ‘always_inline’ function could not be inlined in call to ‘dsl_scan_visitdnode’: function not considered for inlining
dsl_scan.c:699: error: called from here

A work-around is to remove the always inle qualifier, but the question is, if that is wise to do.

diff --git a/module/zfs/dsl_scan.c b/module/zfs/dsl_scan.c
index 297caa0..fa344ea 100644
--- a/module/zfs/dsl_scan.c
+++ b/module/zfs/dsl_scan.c
@@ -599,7 +599,7 @@ dsl_scan_check_resume(dsl_scan_t *scn, const dnode_phys_t *dnp,
  * Return nonzero on i/o error.
  * Return new buf to write out in *bufp.
  */
-inline __attribute__((always_inline)) static int
+inline /* __attribute__((always_inline)) */ static int
 dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype,
     dnode_phys_t *dnp, const blkptr_t *bp,
     const zbookmark_t *zb, dmu_tx_t *tx, arc_buf_t **bufp)
@@ -705,7 +705,7 @@ dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype,
        return (0);
 }
 
-inline __attribute__((always_inline)) static void
+inline /* __attribute__((always_inline)) */ static void
 dsl_scan_visitdnode(dsl_scan_t *scn, dsl_dataset_t *ds,
     dmu_objset_type_t ostype, dnode_phys_t *dnp, arc_buf_t *buf,
     uint64_t object, dmu_tx_t *tx)
diff --git a/module/zfs/zio.c b/module/zfs/zio.c
index bc7b759..594406e 100644
--- a/module/zfs/zio.c
+++ b/module/zfs/zio.c
@@ -1244,7 +1244,7 @@ zio_execute(zio_t *zio)
        __zio_execute(zio);
 }
 
-__attribute__((always_inline))
+/* __attribute__((always_inline)) */
 static inline void
 __zio_execute(zio_t *zio)
 {

[lundman]

That is correct, you can just comment out the "always inline" to compile (But I have not tried more than that).

The Linux version does this to an attempt to save on stack-usage, on the functions that are called recursively. Linux has more restrictive stackusage than Solaris. I do not know where OSX lies in this, or if we will have issues with it in future

[lundman]

We could remove it for all versions until we know if it will break, or use some autoconf checks like
https://github.com/penberg/classpath/blob/master/m4/gcc_attribute.m4
to correctly handle the case where it isn't supported.

[BjoKaSH]

Temporarily fixed by commit 9fc59df. But we still need a proper automake/autoconf check for this.