MdePkg: 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 <hao.a.wu@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

diff --git a/MdePkg/Library/BaseLib/String.c b/MdePkg/Library/BaseLib/String.c
index e84bf50d7f6220a2d911ce3f73f7cb311930f34d..4151e0e7ac5866d992694c8e83fb78ffed3713dc 100644 (file)
--- a/MdePkg/Library/BaseLib/String.c
+++ b/MdePkg/Library/BaseLib/String.c
@@ -586,7 +586,7 @@ InternalHexCharToUintn (
     return Char - L'0';\r
   }\r
 \r
-  return (UINTN) (10 + InternalCharToUpper (Char) - L'A');\r
+  return (10 + InternalCharToUpper (Char) - L'A');\r
 }\r
 \r
 /**\r
@@ -1211,7 +1211,7 @@ InternalAsciiHexCharToUintn (
     return Char - '0';\r
   }\r
 \r
-  return (UINTN) (10 + InternalBaseLibAsciiToUpper (Char) - 'A');\r
+  return (10 + InternalBaseLibAsciiToUpper (Char) - 'A');\r
 }\r
 \r
 \r

diff --git a/MdePkg/Library/BasePeCoffLib/BasePeCoff.c b/MdePkg/Library/BasePeCoffLib/BasePeCoff.c
index 33cad23a014e03998b9a0fcc53d7aca7560daf21..8d1daba4bbe5cc5a2361ff2d3b08b1f7ad8cd160 100644 (file)
--- 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.\r
   PeCoffLoaderGetImageInfo() routine will do basic check for whole PE/COFF image.\r
 \r
-  Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>\r
+  Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>\r
   Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>\r
   This program and the accompanying materials\r
   are licensed and made available under the terms and conditions of the BSD License\r
@@ -703,12 +703,10 @@ PeCoffLoaderGetImageInfo (
       //\r
       DebugDirectoryEntryFileOffset = 0;\r
 \r
-      SectionHeaderOffset = (UINTN)(\r
-                               ImageContext->PeCoffHeaderOffset +\r
-                               sizeof (UINT32) +\r
-                               sizeof (EFI_IMAGE_FILE_HEADER) +\r
-                               Hdr.Pe32->FileHeader.SizeOfOptionalHeader\r
-                               );\r
+      SectionHeaderOffset = ImageContext->PeCoffHeaderOffset +\r
+                            sizeof (UINT32) +\r
+                            sizeof (EFI_IMAGE_FILE_HEADER) +\r
+                            Hdr.Pe32->FileHeader.SizeOfOptionalHeader;\r
 \r
       for (Index = 0; Index < Hdr.Pe32->FileHeader.NumberOfSections; Index++) {\r
         //\r

diff --git a/MdePkg/Library/BaseS3PciLib/S3PciLib.c b/MdePkg/Library/BaseS3PciLib/S3PciLib.c
index e29f7fe63e4c995cc94cb5d367af7b7e7ee2ab34..27342b0eca889d32c915fb9fa5250c4df63af266 100644 (file)
--- 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\r
   maps directly on top of the PciLib class. \r
 \r
-  Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>\r
+  Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>\r
 \r
   This program and the accompanying materials\r
   are licensed and made available under the terms and conditions\r
@@ -25,7 +25,7 @@
 #include <Library/S3PciLib.h>\r
 \r
 #define PCILIB_TO_COMMON_ADDRESS(Address) \\r
-        ((UINT64) ((((UINTN) ((Address>>20) & 0xff)) << 24) + (((UINTN) ((Address>>15) & 0x1f)) << 16) + (((UINTN) ((Address>>12) & 0x07)) << 8) + ((UINTN) (Address & 0xfff ))))\r
+        ((((UINTN) ((Address>>20) & 0xff)) << 24) + (((UINTN) ((Address>>15) & 0x1f)) << 16) + (((UINTN) ((Address>>12) & 0x07)) << 8) + ((UINTN) (Address & 0xfff )))\r
 \r
 /**\r
   Saves a PCI configuration value to the boot script.\r

diff --git a/MdePkg/Library/SmmMemoryAllocationLib/MemoryAllocationLib.c b/MdePkg/Library/SmmMemoryAllocationLib/MemoryAllocationLib.c
index 937165adf9fa60ec988bedfc2cc10ec7b43558c5..592cced5a475aeb13a74a619f0b28a985ab699e0 100644 (file)
--- 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 \r
   return NULL.\r
 \r
-  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>\r
+  Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>\r
   This program and the accompanying materials                          \r
   are licensed and made available under the terms and conditions of the BSD License         \r
   which accompanies this distribution.  The full text of the license may be found at        \r
@@ -343,7 +343,7 @@ InternalAllocateAlignedPages (
       Status = gSmst->SmmFreePages (Memory, UnalignedPages);\r
       ASSERT_EFI_ERROR (Status);\r
     }\r
-    Memory         = (EFI_PHYSICAL_ADDRESS) (AlignedMemory + EFI_PAGES_TO_SIZE (Pages));\r
+    Memory         = AlignedMemory + EFI_PAGES_TO_SIZE (Pages);\r
     UnalignedPages = RealPages - Pages - UnalignedPages;\r
     if (UnalignedPages > 0) {\r
       //\r

diff --git a/MdePkg/Library/UefiMemoryAllocationLib/MemoryAllocationLib.c b/MdePkg/Library/UefiMemoryAllocationLib/MemoryAllocationLib.c
index 3da5e21113b332c4df0751a4ab847ffd1d63ef87..3bd3aefa216d459a80ef2cd44e6c6e24551464ea 100644 (file)
--- a/MdePkg/Library/UefiMemoryAllocationLib/MemoryAllocationLib.c
+++ b/MdePkg/Library/UefiMemoryAllocationLib/MemoryAllocationLib.c
@@ -2,7 +2,7 @@
   Support routines for memory allocation routines based \r
   on boot services for Dxe phase drivers.\r
 \r
-  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>\r
+  Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>\r
   This program and the accompanying materials                          \r
   are licensed and made available under the terms and conditions of the BSD License         \r
   which accompanies this distribution.  The full text of the license may be found at        \r
@@ -216,7 +216,7 @@ InternalAllocateAlignedPages (
       Status = gBS->FreePages (Memory, UnalignedPages);\r
       ASSERT_EFI_ERROR (Status);\r
     }\r
-    Memory         = (EFI_PHYSICAL_ADDRESS) (AlignedMemory + EFI_PAGES_TO_SIZE (Pages));\r
+    Memory         = AlignedMemory + EFI_PAGES_TO_SIZE (Pages);\r
     UnalignedPages = RealPages - Pages - UnalignedPages;\r
     if (UnalignedPages > 0) {\r
       //\r