From bcee1b9f172a606b1c4ee86dcda04c15718c4ed9 Mon Sep 17 00:00:00 2001 From: Hao Wu Date: Wed, 15 Feb 2017 16:04:26 +0800 Subject: IntelFspWrapperPkg: 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: Jiewen Yao --- IntelFspWrapperPkg/FspNotifyDxe/LoadBelow4G.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'IntelFspWrapperPkg/FspNotifyDxe') diff --git a/IntelFspWrapperPkg/FspNotifyDxe/LoadBelow4G.c b/IntelFspWrapperPkg/FspNotifyDxe/LoadBelow4G.c index 6f06e24cae..089413cc3e 100644 --- a/IntelFspWrapperPkg/FspNotifyDxe/LoadBelow4G.c +++ b/IntelFspWrapperPkg/FspNotifyDxe/LoadBelow4G.c @@ -1,6 +1,6 @@ /** @file -Copyright (c) 2015, Intel Corporation. All rights reserved.
+Copyright (c) 2015 - 2017, Intel Corporation. All rights reserved.
This program and the accompanying materials are licensed and made available under the terms and conditions @@ -115,7 +115,7 @@ RelocateImageUnder4GIfNeeded ( // Align buffer on section boundary // ImageContext.ImageAddress += ImageContext.SectionAlignment - 1; - ImageContext.ImageAddress &= ~((EFI_PHYSICAL_ADDRESS)(ImageContext.SectionAlignment - 1)); + ImageContext.ImageAddress &= ~((EFI_PHYSICAL_ADDRESS)ImageContext.SectionAlignment - 1); // // Load the image to our new buffer // -- cgit v1.2.3