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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>
28 lines
799 B
C
28 lines
799 B
C
/** @file
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Local Definitions for the VolInfo utility
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Copyright (c) 1999 - 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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#define PI_SPECIFICATION_VERSION 0x00010000
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#define EFI_DEP_BEFORE 0x00
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#define EFI_DEP_AFTER 0x01
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#define EFI_DEP_PUSH 0x02
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#define EFI_DEP_AND 0x03
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#define EFI_DEP_OR 0x04
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#define EFI_DEP_NOT 0x05
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#define EFI_DEP_TRUE 0x06
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#define EFI_DEP_FALSE 0x07
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#define EFI_DEP_END 0x08
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#define EFI_DEP_SOR 0x09
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#define EFI_SECTION_LAST_LEAF_SECTION_TYPE 0x1C
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#define EFI_SECTION_LAST_SECTION_TYPE 0x1C
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#define OPENSSL_COMMAND_FORMAT_STRING "%s sha1 -out %s %s"
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#define EXTRACT_COMMAND_FORMAT_STRING "%s -d -o %s %s"
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