[edk2-devel] [PATCH EDK2 v2 1/1] MdeModulePkg/FileExplorerLib: remove redundant null pointer check

wenyi,xie via groups.io xiewenyi2=huawei.com at groups.io
Thu Nov 26 01:50:33 UTC 2020


If "Info" is a valid pointer to an EFI_FILE_SYSTEM_VOLUME_LABEL
structure, then "Info->VolumeLabel" denotes a valid array object.
When the "Info->VolumeLabel" expression is evaluated, as seen in
the LibFindFileSystem(), it is implicitly converted to
(&Info->VolumeLabel[0]). Because the object described by the
expression (Info->VolumeLabel[0]) is a valid CHAR16 object, its
address can never compare equal to NULL. Therefore, the condition
(Info->VolumeLabel == NULL) will always evaluate to FALSE.
Substitute the constant FALSE into the "if" statement, and
simplify the resultant code (eliminate the dead branch).

Cc: Jian J Wang <jian.j.wang at intel.com>
Cc: Hao A Wu <hao.a.wu at intel.com>
Cc: Dandan Bi <dandan.bi at intel.com>
Cc: Eric Dong <eric.dong at intel.com>
Signed-off-by: Wenyi Xie <xiewenyi2 at huawei.com>
Reviewed-by: Liming Gao <gaoliming at byosoft.com.cn>
---
 MdeModulePkg/Library/FileExplorerLib/FileExplorer.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/MdeModulePkg/Library/FileExplorerLib/FileExplorer.c b/MdeModulePkg/Library/FileExplorerLib/FileExplorer.c
index 58e49102593c..13a214b06af9 100644
--- a/MdeModulePkg/Library/FileExplorerLib/FileExplorer.c
+++ b/MdeModulePkg/Library/FileExplorerLib/FileExplorer.c
@@ -821,13 +821,9 @@ LibFindFileSystem (
       if (Info == NULL) {
         VolumeLabel = L"NO FILE SYSTEM INFO";
       } else {
-        if (Info->VolumeLabel == NULL) {
-          VolumeLabel = L"NULL VOLUME LABEL";
-        } else {
-          VolumeLabel = Info->VolumeLabel;
-          if (*VolumeLabel == 0x0000) {
-            VolumeLabel = L"NO VOLUME LABEL";
-          }
+        VolumeLabel = Info->VolumeLabel;
+        if (*VolumeLabel == 0x0000) {
+          VolumeLabel = L"NO VOLUME LABEL";
         }
       }
       MenuEntry->DisplayString  = AllocateZeroPool (MAX_CHAR);
-- 
2.20.1.windows.1



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