From 22454f1042f3e56fdcf6c01670220110e4324a70 Mon Sep 17 00:00:00 2001 From: Hao Wu Date: Fri, 17 Feb 2017 11:00:45 +0800 Subject: [PATCH] ShellPkg: Refine casting expression result to bigger size There are cases that the operands of an expression are all with rank less than UINT64/INT64 and the result of the expression is explicitly cast to UINT64/INT64 to fit the target size. An example will be: UINT32 a,b; // a and b can be any unsigned int type with rank less than UINT64, like // UINT8, UINT16, etc. UINT64 c; c = (UINT64) (a + b); Some static code checkers may warn that the expression result might overflow within the rank of "int" (integer promotions) and the result is then cast to a bigger size. The commit refines codes by the following rules: 1). When the expression is possible to overflow the range of unsigned int/ int: c = (UINT64)a + b; 2). When the expression will not overflow within the rank of "int", remove the explicit type casts: c = a + b; 3). When the expression will be cast to pointer of possible greater size: UINT32 a,b; VOID *c; c = (VOID *)(UINTN)(a + b); --> c = (VOID *)((UINTN)a + b); 4). When one side of a comparison expression contains only operands with rank less than UINT32: UINT8 a; UINT16 b; UINTN c; if ((UINTN)(a + b) > c) {...} --> if (((UINT32)a + b) > c) {...} For rule 4), if we remove the 'UINTN' type cast like: if (a + b > c) {...} The VS compiler will complain with warning C4018 (signed/unsigned mismatch, level 3 warning) due to promoting 'a + b' to type 'int'. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Hao Wu Reviewed-by: Ruiyu Ni Reviewed-by: Jaben Carsey --- .../UefiShellDebug1CommandsLib/HexEdit/BufferImage.c | 8 ++++---- ShellPkg/Library/UefiShellLib/UefiShellLib.c | 4 ++-- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/ShellPkg/Library/UefiShellDebug1CommandsLib/HexEdit/BufferImage.c b/ShellPkg/Library/UefiShellDebug1CommandsLib/HexEdit/BufferImage.c index 68d2443d2e..1048ecd415 100644 --- a/ShellPkg/Library/UefiShellDebug1CommandsLib/HexEdit/BufferImage.c +++ b/ShellPkg/Library/UefiShellDebug1CommandsLib/HexEdit/BufferImage.c @@ -2,7 +2,7 @@ Defines HBufferImage - the view of the file that is visible at any point, as well as the event handlers for editing the file - Copyright (c) 2005 - 2014, Intel Corporation. All rights reserved.
+ Copyright (c) 2005 - 2017, Intel Corporation. All rights reserved.
This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at @@ -1108,15 +1108,15 @@ HBufferImageCharToHex ( // change the character to hex // if (Char >= L'0' && Char <= L'9') { - return (INTN) (Char - L'0'); + return (Char - L'0'); } if (Char >= L'a' && Char <= L'f') { - return (INTN) (Char - L'a' + 10); + return (Char - L'a' + 10); } if (Char >= L'A' && Char <= L'F') { - return (INTN) (Char - L'A' + 10); + return (Char - L'A' + 10); } return -1; diff --git a/ShellPkg/Library/UefiShellLib/UefiShellLib.c b/ShellPkg/Library/UefiShellLib/UefiShellLib.c index 536db3c805..55e8a67ac4 100644 --- a/ShellPkg/Library/UefiShellLib/UefiShellLib.c +++ b/ShellPkg/Library/UefiShellLib/UefiShellLib.c @@ -3,7 +3,7 @@ (C) Copyright 2016 Hewlett Packard Enterprise Development LP
Copyright 2016 Dell Inc. - Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.
+ Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.
This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at @@ -3755,7 +3755,7 @@ InternalShellHexCharToUintn ( return Char - L'0'; } - return (UINTN) (10 + InternalShellCharToUpper (Char) - L'A'); + return (10 + InternalShellCharToUpper (Char) - L'A'); } /** -- 2.39.2