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https://github.com/tianocore/edk2
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0e6d10de1c
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.
Note: Some files in BaseTools are excluded from the change if they
are autogenerated or direcly related to a header from a subproject,
etc. In particular, headers in these directories were ignored:
- BaseTools/Source/C/LzmaCompress/Sdk/
- BaseTools/Source/C/VfrCompile/Pccts/
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>
64 lines
1.5 KiB
C
64 lines
1.5 KiB
C
/** @file
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Header file for compression routine.
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Providing both EFI and Tiano Compress algorithms.
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Copyright (c) 2004 - 2018, 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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#include <string.h>
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#include <stdlib.h>
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#include "CommonLib.h"
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#include <Common/UefiBaseTypes.h>
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/**
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Tiano compression routine.
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**/
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EFI_STATUS
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TianoCompress (
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IN UINT8 *SrcBuffer,
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IN UINT32 SrcSize,
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IN UINT8 *DstBuffer,
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IN OUT UINT32 *DstSize
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)
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;
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/**
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Efi compression routine.
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**/
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EFI_STATUS
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EfiCompress (
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IN UINT8 *SrcBuffer,
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IN UINT32 SrcSize,
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IN UINT8 *DstBuffer,
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IN OUT UINT32 *DstSize
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)
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;
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/**
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The compression routine.
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@param SrcBuffer The buffer storing the source data
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@param SrcSize The size of source data
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@param DstBuffer The buffer to store the compressed data
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@param DstSize On input, the size of DstBuffer; On output,
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the size of the actual compressed data.
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@retval EFI_BUFFER_TOO_SMALL The DstBuffer is too small. In this case,
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DstSize contains the size needed.
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@retval EFI_SUCCESS Compression is successful.
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@retval EFI_OUT_OF_RESOURCES No resource to complete function.
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@retval EFI_INVALID_PARAMETER Parameter supplied is wrong.
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**/
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typedef
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EFI_STATUS
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(*COMPRESS_FUNCTION) (
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IN UINT8 *SrcBuffer,
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IN UINT32 SrcSize,
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IN UINT8 *DstBuffer,
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IN OUT UINT32 *DstSize
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);
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