[PATCH XEN v7 18/29] tools/libs/foreignmemory: pull array length argument to map forward

[Ian Campbell <ian.campbell@citrix.com>]

By having the "num" argument before the page and error arrays we can
potentially use a variable-length-array argument ("int pages[num]") in
the function prototype.

However VLAs are a C99 feature and we are currently targetting C89 and
later, so we don't actually make use of this here, merely arrange that
we can switch to VLAs in the future without changing the function ABI.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
---
v6: New
---
 tools/libs/foreignmemory/compat.c                   | 4 ++--
 tools/libs/foreignmemory/core.c                     | 5 +++--
 tools/libs/foreignmemory/freebsd.c                  | 4 ++--
 tools/libs/foreignmemory/include/xenforeignmemory.h | 4 ++--
 tools/libs/foreignmemory/linux.c                    | 3 ++-
 tools/libs/foreignmemory/minios.c                   | 3 ++-
 tools/libs/foreignmemory/private.h                  | 3 ++-
 tools/libxc/xc_foreign_memory.c                     | 4 ++--
 tools/libxc/xc_sr_restore.c                         | 2 +-
 tools/libxc/xc_sr_save.c                            | 2 +-
 10 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/tools/libs/foreignmemory/compat.c b/tools/libs/foreignmemory/compat.c
index 039297c..b79ec1a 100644
--- a/tools/libs/foreignmemory/compat.c
+++ b/tools/libs/foreignmemory/compat.c
@@ -22,8 +22,8 @@
 #include "private.h"
 
 void *osdep_xenforeignmemory_map(xenforeignmemory_handle *fmem,
-                                 uint32_t dom, int prot,
-                                 const xen_pfn_t *arr, int *err, size_t num)
+                                 uint32_t dom, int prot, size_t num,
+                                 const xen_pfn_t arr[/*num*/], int err[/*num*/])
 {
     xen_pfn_t *pfn;
     unsigned int i;
diff --git a/tools/libs/foreignmemory/core.c b/tools/libs/foreignmemory/core.c
index 4e0541f..cfb0a73 100644
--- a/tools/libs/foreignmemory/core.c
+++ b/tools/libs/foreignmemory/core.c
@@ -64,7 +64,8 @@ int xenforeignmemory_close(xenforeignmemory_handle *fmem)
 
 void *xenforeignmemory_map(xenforeignmemory_handle *fmem,
                            uint32_t dom, int prot,
-                           const xen_pfn_t *arr, int *err, size_t num)
+                           size_t num,
+                           const xen_pfn_t arr[/*num*/], int err[/*num*/])
 {
     void *ret;
     int *err_to_free = NULL;
@@ -75,7 +76,7 @@ void *xenforeignmemory_map(xenforeignmemory_handle *fmem,
     if ( err == NULL )
         return NULL;
 
-    ret = osdep_xenforeignmemory_map(fmem, dom, prot, arr, err, num);
+    ret = osdep_xenforeignmemory_map(fmem, dom, prot, num, arr, err);
 
     if ( ret == 0 && err_to_free )
     {
diff --git a/tools/libs/foreignmemory/freebsd.c b/tools/libs/foreignmemory/freebsd.c
index ed26ebb..703754f 100644
--- a/tools/libs/foreignmemory/freebsd.c
+++ b/tools/libs/foreignmemory/freebsd.c
@@ -84,8 +84,8 @@ int osdep_xenforeignmemory_close(xenforeignmemory_handle *fmem)
 
 void *osdep_xenforeignmemory_map(xenforeignmemory_handle *fmem,
                                  uint32_t dom, int prot,
-                                 const xen_pfn_t *arr, int *err,
-                                 size_t num)
+                                 size_t num,
+                                 const xen_pfn_t arr[/*num*/], int err[/*num*/])
 {
     int fd = fmem->fd;
     privcmd_mmapbatch_t ioctlx;
diff --git a/tools/libs/foreignmemory/include/xenforeignmemory.h b/tools/libs/foreignmemory/include/xenforeignmemory.h
index b162dca..d75f946 100644
--- a/tools/libs/foreignmemory/include/xenforeignmemory.h
+++ b/tools/libs/foreignmemory/include/xenforeignmemory.h
@@ -104,8 +104,8 @@ int xenforeignmemory_close(xenforeignmemory_handle *xmem);
  * of @err indicating failure to map every page.
  */
 void *xenforeignmemory_map(xenforeignmemory_handle *fmem, uint32_t dom,
-                           int prot, const xen_pfn_t *arr, int *err,
-                           size_t pages);
+                           int prot, size_t pages,
+                           const xen_pfn_t arr[/*pages*/], int err[/*pages*/]);
 
 /*
  * Unmap a mapping previous created with xenforeignmemory_map().
diff --git a/tools/libs/foreignmemory/linux.c b/tools/libs/foreignmemory/linux.c
index 6620391..32b6def 100644
--- a/tools/libs/foreignmemory/linux.c
+++ b/tools/libs/foreignmemory/linux.c
@@ -161,7 +161,8 @@ out:
 
 void *osdep_xenforeignmemory_map(xenforeignmemory_handle *fmem,
                                  uint32_t dom, int prot,
-                                 const xen_pfn_t *arr, int *err, size_t num)
+                                 size_t num,
+                                 const xen_pfn_t arr[/*num*/], int err[/*num*/])
 {
     int fd = fmem->fd;
     privcmd_mmapbatch_v2_t ioctlx;
diff --git a/tools/libs/foreignmemory/minios.c b/tools/libs/foreignmemory/minios.c
index bdc1239..ca5ba71 100644
--- a/tools/libs/foreignmemory/minios.c
+++ b/tools/libs/foreignmemory/minios.c
@@ -41,7 +41,8 @@ int osdep_xenforeignmemory_close(xenforeignmemory_handle *fmem)
 
 void *osdep_xenforeignmemory_map(xenforeignmemory_handle *fmem,
                                  uint32_t dom, int prot,
-                                 const xen_pfn_t *arr, int *err, size_t num)
+                                 size_t num,
+                                 const xen_pfn_t arr[/*num*/], int err[/*num*/])
 {
     unsigned long pt_prot = 0;
     if (prot & PROT_READ)
diff --git a/tools/libs/foreignmemory/private.h b/tools/libs/foreignmemory/private.h
index 36a71ec..cd732fd 100644
--- a/tools/libs/foreignmemory/private.h
+++ b/tools/libs/foreignmemory/private.h
@@ -27,7 +27,8 @@ int osdep_xenforeignmemory_close(xenforeignmemory_handle *fmem);
 
 void *osdep_xenforeignmemory_map(xenforeignmemory_handle *fmem,
                                  uint32_t dom, int prot,
-                                 const xen_pfn_t *arr, int *err, size_t num);
+                                 size_t num,
+                                 const xen_pfn_t arr[num], int err[num]);
 int osdep_xenforeignmemory_unmap(xenforeignmemory_handle *fmem,
                                  void *addr, size_t num);
 
diff --git a/tools/libxc/xc_foreign_memory.c b/tools/libxc/xc_foreign_memory.c
index 4b24388..4053d26 100644
--- a/tools/libxc/xc_foreign_memory.c
+++ b/tools/libxc/xc_foreign_memory.c
@@ -28,7 +28,7 @@ void *xc_map_foreign_pages(xc_interface *xch, uint32_t dom, int prot,
         return NULL;
     }
 
-    return xenforeignmemory_map(xch->fmem, dom, prot, arr, NULL, num);
+    return xenforeignmemory_map(xch->fmem, dom, prot, num, arr, NULL);
 }
 
 void *xc_map_foreign_range(xc_interface *xch,
@@ -84,7 +84,7 @@ void *xc_map_foreign_ranges(xc_interface *xch,
 void *xc_map_foreign_bulk(xc_interface *xch, uint32_t dom, int prot,
                           const xen_pfn_t *arr, int *err, unsigned int num)
 {
-    return xenforeignmemory_map(xch->fmem, dom, prot, arr, err, num);
+    return xenforeignmemory_map(xch->fmem, dom, prot, num, arr, err);
 }
 
 /*
diff --git a/tools/libxc/xc_sr_restore.c b/tools/libxc/xc_sr_restore.c
index a334efd..d6d2397 100644
--- a/tools/libxc/xc_sr_restore.c
+++ b/tools/libxc/xc_sr_restore.c
@@ -318,7 +318,7 @@ static int process_page_data(struct xc_sr_context *ctx, unsigned count,
 
     mapping = guest_page = xenforeignmemory_map(xch->fmem,
         ctx->domid, PROT_READ | PROT_WRITE,
-        mfns, map_errs, nr_pages);
+        nr_pages, mfns, map_errs);
     if ( !mapping )
     {
         rc = -1;
diff --git a/tools/libxc/xc_sr_save.c b/tools/libxc/xc_sr_save.c
index 3d78970..4894a57 100644
--- a/tools/libxc/xc_sr_save.c
+++ b/tools/libxc/xc_sr_save.c
@@ -154,7 +154,7 @@ static int write_batch(struct xc_sr_context *ctx)
     if ( nr_pages > 0 )
     {
         guest_mapping = xenforeignmemory_map(xch->fmem,
-            ctx->domid, PROT_READ, mfns, errors, nr_pages);
+            ctx->domid, PROT_READ, nr_pages, mfns, errors);
         if ( !guest_mapping )
         {
             PERROR("Failed to map guest pages");
-- 
2.1.4