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648ea00a19
Replace traditional `#ifndef`/`#define`/`#endif` include guards with
`#pragma` once.
`#pragma once` is a widely supported preprocessor directive that
prevents header files from being included multiple times. It is
supported by all toolchains used to build edk2: GCC, Clang/LLVM, and
MSVC.
Compared to macro-based include guards, `#pragma once`:
- Eliminates the risk of macro name collisions or copy/paste errors
where two headers inadvertently use the same guard macro.
- Eliminate inconsistency in the way include guard macros are named
(e.g., some files use `__FILE_H__`, others use `FILE_H_`, etc.).
- Reduces boilerplate (three lines replaced by one).
- Avoids polluting the macro namespace with guard symbols.
- Can improve build times as the preprocessor can skip re-opening the
file entirely, rather than re-reading it to find the matching
`#endif` ("multiple-include optimization").
- Note that some compilers may already optimize traditional include
guards, by recognzining the idiomatic pattern.
This change is made acknowledging that overall portability of the
code will technically be reduced, as `#pragma once` is not part of the
C/C++ standards.
However, this is considered acceptable given:
1. edk2 already defines a subset of supported compilers in
BaseTools/Conf/tools_def.template, all of which have supported
`#pragma once` for over two decades.
2. There have been concerns raised to the project about inconsistent
include guard naming and potential macro collisions.
Approximate compiler support dates:
- MSVC: Supported since Visual C++ 4.2 (1996)
- GCC: Supported since 3.4 (2004)
(http://gnu.ist.utl.pt/software/gcc/gcc-3.4/changes.html)
- Clang (LLVM based): Since initial release in 2007
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
42 lines
1.1 KiB
C
42 lines
1.1 KiB
C
/** @file
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Fsp related definitions
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Copyright (c) 2014 - 2016, Intel Corporation. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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#pragma once
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//
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// Fv Header
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//
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#define FVH_FV_LENGTH_OFFSET 0x20
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#define FVH_SIGINATURE_OFFSET 0x28
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#define FVH_SIGINATURE_VALID_VALUE 0x4856465F // valid signature:_FVH
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#define FVH_HEADER_LENGTH_OFFSET 0x30
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#define FVH_EXTHEADER_OFFSET_OFFSET 0x34
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#define FVH_EXTHEADER_SIZE_OFFSET 0x10
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//
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// Ffs Header
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//
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#define FSP_HEADER_SIGNATURE_OFFSET 0x1C
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#define FSP_HEADER_SIGNATURE 0x48505346 ; valid signature:FSPH
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#define FSP_HEADER_GUID_DWORD1 0x912740BE
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#define FSP_HEADER_GUID_DWORD2 0x47342284
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#define FSP_HEADER_GUID_DWORD3 0xB08471B9
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#define FSP_HEADER_GUID_DWORD4 0x0C3F3527
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#define FFS_HEADER_SIZE_VALUE 0x18
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//
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// Section Header
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//
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#define SECTION_HEADER_TYPE_OFFSET 0x03
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#define RAW_SECTION_HEADER_SIZE_VALUE 0x04
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//
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// Fsp Header
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//
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#define FSP_HEADER_IMAGEBASE_OFFSET 0x1C
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#define FSP_HEADER_TEMPRAMINIT_OFFSET 0x30
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