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From: Hao Wu <hao.a.wu@intel.com>
To: edk2-devel@lists.01.org
Cc: Hao Wu <hao.a.wu@intel.com>,
	Michael Kinney <michael.d.kinney@intel.com>,
	Liming Gao <liming.gao@intel.com>,
	Eric Dong <eric.dong@intel.com>
Subject: [PATCH 1/1] MdePkg: Refine casting expression result to bigger size
Date: Sun, 22 Jan 2017 14:43:54 +0800	[thread overview]
Message-ID: <1485067434-12064-2-git-send-email-hao.a.wu@intel.com> (raw)
In-Reply-To: <1485067434-12064-1-git-send-email-hao.a.wu@intel.com>

There are cases that the operands of an expression are all with rank less
than UINT64/INT64 and the result of the expression is casted 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.

For the consideration of generated binaries size, the commit will keep the
size of the operands as the size of int, and explitly add a type cast
before converting the result to UINT64/INT64.

1). When there is no operand with type UINTN
(UINTN)  (a + b) -> (UINTN)(UINT32)  (a + b) or
(UINT64) (a + b) -> (UINT64)(UINT32) (a + b)

2). Otherwise
(UINT64) (a + b) -> (UINT64)(UINTN)  (a + b)

Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
---
 MdePkg/Library/BaseLib/String.c                              | 4 ++--
 MdePkg/Library/BasePeCoffLib/BasePeCoff.c                    | 4 ++--
 MdePkg/Library/BaseS3PciLib/S3PciLib.c                       | 4 ++--
 MdePkg/Library/SmmMemoryAllocationLib/MemoryAllocationLib.c  | 4 ++--
 MdePkg/Library/UefiMemoryAllocationLib/MemoryAllocationLib.c | 4 ++--
 5 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/MdePkg/Library/BaseLib/String.c b/MdePkg/Library/BaseLib/String.c
index e84bf50..82aa405 100644
--- a/MdePkg/Library/BaseLib/String.c
+++ b/MdePkg/Library/BaseLib/String.c
@@ -586,7 +586,7 @@ InternalHexCharToUintn (
     return Char - L'0';
   }
 
-  return (UINTN) (10 + InternalCharToUpper (Char) - L'A');
+  return (UINTN)(UINT32) (10 + InternalCharToUpper (Char) - L'A');
 }
 
 /**
@@ -1211,7 +1211,7 @@ InternalAsciiHexCharToUintn (
     return Char - '0';
   }
 
-  return (UINTN) (10 + InternalBaseLibAsciiToUpper (Char) - 'A');
+  return (UINTN)(UINT32) (10 + InternalBaseLibAsciiToUpper (Char) - 'A');
 }
 
 
diff --git a/MdePkg/Library/BasePeCoffLib/BasePeCoff.c b/MdePkg/Library/BasePeCoffLib/BasePeCoff.c
index 33cad23..d7f5fd0 100644
--- a/MdePkg/Library/BasePeCoffLib/BasePeCoff.c
+++ b/MdePkg/Library/BasePeCoffLib/BasePeCoff.c
@@ -15,7 +15,7 @@
   PeCoffLoaderGetPeHeader() routine will do basic check for PE/COFF header.
   PeCoffLoaderGetImageInfo() routine will do basic check for whole PE/COFF image.
 
-  Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
   Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
@@ -703,7 +703,7 @@ PeCoffLoaderGetImageInfo (
       //
       DebugDirectoryEntryFileOffset = 0;
 
-      SectionHeaderOffset = (UINTN)(
+      SectionHeaderOffset = (UINTN)(UINT32)(
                                ImageContext->PeCoffHeaderOffset +
                                sizeof (UINT32) +
                                sizeof (EFI_IMAGE_FILE_HEADER) +
diff --git a/MdePkg/Library/BaseS3PciLib/S3PciLib.c b/MdePkg/Library/BaseS3PciLib/S3PciLib.c
index e29f7fe..d712c64 100644
--- a/MdePkg/Library/BaseS3PciLib/S3PciLib.c
+++ b/MdePkg/Library/BaseS3PciLib/S3PciLib.c
@@ -3,7 +3,7 @@
   the PCI operations to be replayed during an S3 resume. This library class
   maps directly on top of the PciLib class. 
 
-  Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
 
   This program and the accompanying materials
   are licensed and made available under the terms and conditions
@@ -25,7 +25,7 @@
 #include <Library/S3PciLib.h>
 
 #define PCILIB_TO_COMMON_ADDRESS(Address) \
-        ((UINT64) ((((UINTN) ((Address>>20) & 0xff)) << 24) + (((UINTN) ((Address>>15) & 0x1f)) << 16) + (((UINTN) ((Address>>12) & 0x07)) << 8) + ((UINTN) (Address & 0xfff ))))
+        ((UINT64)(UINTN) ((((UINTN) ((Address>>20) & 0xff)) << 24) + (((UINTN) ((Address>>15) & 0x1f)) << 16) + (((UINTN) ((Address>>12) & 0x07)) << 8) + ((UINTN) (Address & 0xfff ))))
 
 /**
   Saves a PCI configuration value to the boot script.
diff --git a/MdePkg/Library/SmmMemoryAllocationLib/MemoryAllocationLib.c b/MdePkg/Library/SmmMemoryAllocationLib/MemoryAllocationLib.c
index 937165a..8321b6c 100644
--- a/MdePkg/Library/SmmMemoryAllocationLib/MemoryAllocationLib.c
+++ b/MdePkg/Library/SmmMemoryAllocationLib/MemoryAllocationLib.c
@@ -12,7 +12,7 @@
   allocation for the Reserved memory types are not supported and will always 
   return NULL.
 
-  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
   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        
@@ -343,7 +343,7 @@ InternalAllocateAlignedPages (
       Status = gSmst->SmmFreePages (Memory, UnalignedPages);
       ASSERT_EFI_ERROR (Status);
     }
-    Memory         = (EFI_PHYSICAL_ADDRESS) (AlignedMemory + EFI_PAGES_TO_SIZE (Pages));
+    Memory         = (EFI_PHYSICAL_ADDRESS)(UINTN) (AlignedMemory + EFI_PAGES_TO_SIZE (Pages));
     UnalignedPages = RealPages - Pages - UnalignedPages;
     if (UnalignedPages > 0) {
       //
diff --git a/MdePkg/Library/UefiMemoryAllocationLib/MemoryAllocationLib.c b/MdePkg/Library/UefiMemoryAllocationLib/MemoryAllocationLib.c
index 3da5e211..d818f9c 100644
--- a/MdePkg/Library/UefiMemoryAllocationLib/MemoryAllocationLib.c
+++ b/MdePkg/Library/UefiMemoryAllocationLib/MemoryAllocationLib.c
@@ -2,7 +2,7 @@
   Support routines for memory allocation routines based 
   on boot services for Dxe phase drivers.
 
-  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
   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        
@@ -216,7 +216,7 @@ InternalAllocateAlignedPages (
       Status = gBS->FreePages (Memory, UnalignedPages);
       ASSERT_EFI_ERROR (Status);
     }
-    Memory         = (EFI_PHYSICAL_ADDRESS) (AlignedMemory + EFI_PAGES_TO_SIZE (Pages));
+    Memory         = (EFI_PHYSICAL_ADDRESS)(UINTN) (AlignedMemory + EFI_PAGES_TO_SIZE (Pages));
     UnalignedPages = RealPages - Pages - UnalignedPages;
     if (UnalignedPages > 0) {
       //
-- 
1.9.5.msysgit.0



  reply	other threads:[~2017-01-22  6:44 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-22  6:43 [PATCH 0/1] Refine casting expression result to bigger size Hao Wu
2017-01-22  6:43 ` Hao Wu [this message]
2017-01-23 11:01 ` Laszlo Ersek
2017-01-23 20:58   ` Ard Biesheuvel
2017-01-24  5:53     ` Wu, Hao A

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