[PATCH 03/19] OvmfPkg/XenBusDxe: eliminate AsciiStrCat() calls

[Laszlo Ersek <lersek@redhat.com>]

AsciiStrCat() is deprecated / disabled under the
DISABLE_NEW_DEPRECATED_INTERFACES feature test macro.

Replace AsciiStrCat() with AsciiSPrint(). Spell out the (already existent)
PrintLib dependency in the INF file. Add an explicit ASSERT() to document
that XenStoreJoin() assumes that the pool allocation always succeeds.

Cc: Anthony PERARD <anthony.perard@citrix.com>
Cc: Gary Lin <glin@suse.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=166
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---

Notes:
    not used in my setup, testing would be appreciated

 OvmfPkg/XenBusDxe/XenBusDxe.inf |  1 +
 OvmfPkg/XenBusDxe/XenStore.c    | 15 +++++++++------
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/OvmfPkg/XenBusDxe/XenBusDxe.inf b/OvmfPkg/XenBusDxe/XenBusDxe.inf
index f0c5db98b1f4..5ff1cd04840c 100644
--- a/OvmfPkg/XenBusDxe/XenBusDxe.inf
+++ b/OvmfPkg/XenBusDxe/XenBusDxe.inf
@@ -56,6 +56,7 @@ [LibraryClasses]
   DebugLib
   XenHypercallLib
   SynchronizationLib
+  PrintLib
 
 [Protocols]
   gEfiDriverBindingProtocolGuid
diff --git a/OvmfPkg/XenBusDxe/XenStore.c b/OvmfPkg/XenBusDxe/XenStore.c
index aa3ff7d3017b..b7ae1d04863d 100644
--- a/OvmfPkg/XenBusDxe/XenStore.c
+++ b/OvmfPkg/XenBusDxe/XenStore.c
@@ -303,14 +303,17 @@ XenStoreJoin (
   )
 {
   CHAR8 *Buf;
+  UINTN BufSize;
 
   /* +1 for '/' and +1 for '\0' */
-  Buf = AllocateZeroPool (
-          AsciiStrLen (DirectoryPath) + AsciiStrLen (Node) + 2);
-  AsciiStrCat (Buf, DirectoryPath);
-  if (Node[0] != '\0') {
-    AsciiStrCat (Buf, "/");
-    AsciiStrCat (Buf, Node);
+  BufSize = AsciiStrLen (DirectoryPath) + AsciiStrLen (Node) + 2;
+  Buf = AllocatePool (BufSize);
+  ASSERT (Buf != NULL);
+
+  if (Node[0] == '\0') {
+    AsciiSPrint (Buf, BufSize, "%a", DirectoryPath);
+  } else {
+    AsciiSPrint (Buf, BufSize, "%a/%a", DirectoryPath, Node);
   }
 
   return Buf;
-- 
2.9.2