MdeModulePkg: 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: Feng Tian <feng.tian@intel.com>
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@@ -2,7 +2,7 @@
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This code produces the Smbios protocol. It also responsible for constructing
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SMBIOS table into system table.
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Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>
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Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR>
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This program and the accompanying materials
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are licensed and made available under the terms and conditions of the BSD License
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which accompanies this distribution. The full text of the license may be found at
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@@ -1138,7 +1138,7 @@ SmbiosCreateTable (
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EntryPointStructure->MaxStructureSize = (UINT16) sizeof (EndStructure);
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}
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if ((UINTN) EFI_SIZE_TO_PAGES (EntryPointStructure->TableLength) > mPreAllocatedPages) {
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if (EFI_SIZE_TO_PAGES ((UINT32) EntryPointStructure->TableLength) > mPreAllocatedPages) {
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//
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// If new SMBIOS table size exceeds the previous allocated page,
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// it is time to re-allocate memory (below 4GB).
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@@ -1307,7 +1307,7 @@ SmbiosCreate64BitTable (
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EndStructure.Tailing[1] = 0;
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Smbios30EntryPointStructure->TableMaximumSize = (UINT32) (Smbios30EntryPointStructure->TableMaximumSize + sizeof (EndStructure));
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if ((UINTN) EFI_SIZE_TO_PAGES (Smbios30EntryPointStructure->TableMaximumSize) > mPre64BitAllocatedPages) {
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if (EFI_SIZE_TO_PAGES (Smbios30EntryPointStructure->TableMaximumSize) > mPre64BitAllocatedPages) {
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//
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// If new SMBIOS table size exceeds the previous allocated page,
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// it is time to re-allocate memory at anywhere.
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